sodium-pertechnetate-tc-99m and Hypothyroidism

The etiology of congenital hypothyroidism (CH) may play an important role in determining disease severity, outcome, and, therefore, its treatment schedule. Radionuclide imaging (RI) is currently the most precise diagnostic technique to establish the etiology of CH. Conventional ultrasound can identify an athyrotic condition at the normal neck position and has gained acceptance for the initial evaluation of CH; however, its ability in delineating ectopic thyroid is limited. We used color Doppler ultrasonography (CDU) to assess blood flow and morphology in the detection of ectopic thyroid in 11 CH patients disclosed by neonatal screening; thyroid glands were undetectable at the normal location by gray-scale ultrasonography (GSU). The patients studied consisted of two infants for initial investigation and nine children for reevaluating the cause of CH. All of the patients underwent GSU, CDU, RI, and magnetic resonance imaging (MRI) investigation. We set RI as the defining diagnostic test for detecting ectopic thyroid and compared the imaging of CDU with those of GSU and MRI. The results of RI showed 10 ectopic thyroids and one athyreosis. In the patients with ectopic thyroid, the sensitivity of CDU, GSU, and MRI for detecting ectopic thyroid was 90, 70, and 70%, respectively. We conclude that CDU is superior to GSU and MRI for detecting ectopic thyroid and that CDU may be adopted as the diagnostic tool for the initial investigation of suspected CH.

Topics: Adolescent; Adult; Child; Child, Preschool; Choristoma; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant; Infant, Newborn; Magnetic Resonance Imaging; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Tongue Diseases; Ultrasonography, Doppler, Color

The aim of this study was to investigate the frequency and mechanisms of hypothyroidism observed in diabetic patients with advanced diabetic nephropathy, including outcomes of management for this condition. A controlled study was designed using 32 diabetic and 31 non-diabetic patients not receiving hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) who excreted mean urinary protein greater than 0.5 g/day examined on three consecutive days during admission to our hospital. Thyroid hormones in both serum and urine, anti-thyroid antibodies, renal function and iodine concentrations in serum were measured during admission in all patients included. In particular, in patients who showed overt hypothyroidism, further studies including large-needle biopsies of the thyroid and iodine-perchlorate discharge tests were performed. All patients in the two groups revealed negative antithyroid antibody titers, and the mean serum total iodine levels did not significantly differ between the two groups. Mean serum FT4 levels significantly decreased, and the TSH level was significantly elevated in the diabetic group compared to those in the non-diabetic group (p < 0.005, p < 0.02, respectively). The frequency of overt hypothyroidism in the diabetic group (22%; 7/32) was significantly higher (p < 0.05) than that in the non-diabetic group (3.2%; 1/31). The daily urinary thyroid hormone excretion in both groups did not show any significant correlation with serum thyroid hormone levels. Seven patients who revealed overt hypothyroidism in the diabetic group showed elevated serum total iodine levels during hypothyroidal status, ranging between 177 and 561 microg/l. Also, the iodine-perchlorate discharge tests carried out in six of these patients all showed a positive discharge. After management based on iodine restriction, normalization of serum thyroid hormone levels in accordance with definite decreases in the serum total iodine level was achieved, accompanied by a significant weight reduction. In conclusion, we found a significantly high prevalence of non-autoimmune primary hypothyroidism in patients with advanced diabetic nephropathy compared to those with non-diabetic chronic renal dysfunction, which may partly relate to earlier development of oedematous status. Clinical and laboratory findings suggest that impaired renal handling of iodine resulting in an elevation of serum iodine levels, rather than autoimmune mechanism or urinary hormone loss, may play a princ

Topics: Aged; Antibodies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Goiter; Humans; Hypothyroidism; Kidney Failure, Chronic; Luminescent Measurements; Male; Middle Aged; Proteinuria; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroglobulin; Thyroid Function Tests; Thyroid Gland; Thyroid Hormones; Treatment Outcome

The presented study prospectively evaluates the efficacy of optimized radioiodine therapy in patients (pts) with multifocal (MFA) and disseminated (DISA) autonomy. The target dose was related to the total thyroid volume and was increased in moderate and nonlinear increments from 150 to 300 Gy dependent on the pretherapeutic Tc-99m pertechnetate thyroid uptake under suppression (TcTUs). Patients with focal autonomy were treated with a target dose independent of TcTUs and were used as control group.. The data of 641 pts (518 women, 123 men) were evaluated, 466 pts with MFA or DISA and 175 pts with focal autonomy. In pts with MFA and DISA the target dose was increased in four steps: TcTUs < 3%: 150 Gy, > 3-6%: 200 Gy, > 6-12%: 250 Gy and > 12%: 300 Gy. In pts with focal autonomy a fixed target dose of 300 or 400 Gy was applied. The radioactivity to be administered was calculated using a modified Marinelli formula. The follow-up examination was performed at the earliest after four, on average after eight months. Normalization of TSH was the only criterion for successful therapy.. The success rate in pts with latent or manifest hyperthyroidism in focal autonomy was 91.5%, therapy was not successful in 5.1% and hypothyroidism occurred in 3.4%. The average success rate in pts with MFA and DISA was 91.5%, therapy failed in 7.5% and a very low rate of 1% with hypothyroidism was seen.. The presented optimized therapy concept with calculated, nonlinear increase of the target dose according to the TcTUs-level guaranteed even in MFA and DISA a high success rate comparable to that in focal autonomy along with a very low rate of hypothyroidism.

Topics: Female; Humans; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland

Technetium-99m pertechnetate (Tc-99m) scan is presently the best diagnostic modality to delineate the anatomy of the neonatal thyroid. Because several factors will inhibit Tc-99m uptake in a normal thyroid gland and the Tc-99m scan requires expensive equipment and sometimes raises fear of radiation in parents, the ultrasonography might be an important complementary method for neonatal thyroid disorders. We described our experience with ultrasonography of the thyroid in 52 infants with suspected congenital hypothyroidism to compare the results obtained by using Tc-99m imaging in the same infants.. From Dec. 1991 to May 1992, 52 neonates with suspected congenital hypothyroidism by newborn screening were referred to Veterans General Hospital-Taipei for confirmatory diagnoses. All of them were investigated with Tc-99m and ultrasonography of the thyroid gland. Results of Tc-99m scan and ultrasonography were compared and analyzed.. The ultrasonography failed to identify any ectopic gland and all cases were misinterpreted as hypoplasia or hemiagenesis of thyroid gland, but it never misinterpreted them as normal thyroid glands. The ultrasound never misinterpreted normal thyroid gland, while the Tc-99m scan misguided a normal gland as an athyreotic gland.. The ultrasonography may be adopted as the first line image examination for the babies with suspected congenital hypothyroidism. If sonography shows abnormal thyroid gland such as hypoplasia, hemiagenesis or agenesis, the isotopic scan may be a good complementary method to confirm the diagnosis.

Topics: Female; Humans; Hypothyroidism; Infant; Male; Predictive Value of Tests; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Ultrasonography

The presence of ectopic thyroid tissue in 2 or more different sites is rare. A 12-year-old girl presented with midline anterior neck swelling in the infrahyoid region with subclinical hypothyroidism. Thyroid scanning with Tc-pertechnetate was performed, and SPECT/CT was ordered for further evaluation. Two hyperdense lesions demonstrating intense radiotracer uptake were seen in the midline at the base of the tongue and infrahyoid neck. We emphasis the role of hybrid SPECT/CT for characterization and localization of suspected ectopic thyroid tissue.

Topics: Biological Transport; Child; Female; Humans; Hypothyroidism; Single Photon Emission Computed Tomography Computed Tomography; Sodium Pertechnetate Tc 99m; Thyroid Dysgenesis

To determine the diagnostic and predictive value of ultrasound and radioisotope scans of the thyroid, alone and in combination, during a single visit after initial referral by the screening laboratory with thyroid-stimulating hormone (TSH) elevation.. Retrospective blind review of ultrasound and radioisotope images followed by final diagnosis based on clinical features, biochemistry, imaging, and molecular genetic study.. Infants (n = 97; 61 female) with median birthweight 3.38 kg (range 2.04-4.86) and gestation 40 weeks (range 33-42), underwent successful dual thyroid ultrasound and technetium-99m pertechnetate radioisotope scan in a single center. Combined scanning at the initial visit resulted in a correct final diagnosis in 79 of 97 (81%) cases. One patient was misdiagnosed initially as having athyreosis as the result of delayed radioisotope scan and the diagnosis of ectopia made later on diagnostic challenge. The specificity/sensitivity for radioisotope scan and for ultrasound was as follows: 100%/97% and 100%/55% for ectopia (n = 39); 81%/100% and 54%/100% for athyreosis (n = 18); and 89%/90% and 80%/95% for dyshormonogenesis (n = 20). Neither modality, alone or in combination, predicted final diagnosis in eutopic glands due to hypoplasia (n = 4), transient TSH elevation (n = 12), and status still uncertain (n = 4).. More than 80% of newborn infants with TSH elevation can be diagnosed correctly on initial imaging with combined radioisotope scan and ultrasound. Ultrasound cannot reliably detect thyroid ectopia. Radioisotope scan, especially if performed late, may show no uptake despite the presence of a eutopic gland.

Topics: Female; Humans; Hypothyroidism; Infant, Newborn; Male; Multimodal Imaging; Neonatal Screening; Predictive Value of Tests; Radionuclide Imaging; Radiopharmaceuticals; Referral and Consultation; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyrotropin; Ultrasonography

To assess the value of thyroid scintigraphy to determine thyroid status in dogs with hypothyroidism and various non-thyroidal illnesses.. Thyroid hormone concentrations were measured and quantitative thyroid scintigraphy performed in 21 dogs with clinical and/or clinicopathological features consistent with hypothyroidism.. In 14 dogs with technetium thyroidal uptake values consistent with euthyroidism, further investigations supported non-thyroidal illness. In five dogs with technetium thyroidal uptake values within the hypothyroid range, primary hypothyroidism was confirmed as the only disease in four. The remaining dog had pituitary-dependent hyperadrenocorticism. Two dogs had technetium thyroidal uptake values in the non-diagnostic range. One dog had iodothyronine concentrations indicative of euthyroidism. In the other, a dog receiving glucocorticoid therapy, all iodothyronine concentrations were decreased. Markedly asymmetric technetium thyroidal uptake was present in two dogs. All iodothyronine concentrations were within reference interval but canine thyroid stimulating hormone concentration was elevated in one. Non-thyroidal illness was identified in both cases.. In dogs, technetium thyroidal uptake is a useful test to determine thyroid function. However, values may be non-diagnostic, asymmetric uptake can occur and excess glucocorticoids may variably suppress technetium thyroidal uptake and/or thyroid hormone concentrations. Further studies are necessary to evaluate quantitative thyroid scintigraphy as a gold standard method for determining canine thyroid function.

Topics: Adrenocortical Hyperfunction; Animals; Dog Diseases; Dogs; Female; Hypothyroidism; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Diseases; Thyroid Function Tests; Thyroid Gland; Thyroid Hormones

This study investigated the recombinant human thyrotropin (rhTSH) stimulation test in healthy cats (group 1), cats with non-thyroidal illness (group 2) and cats with low serum total T(4) (TT(4)) and azotaemia after (131)I treatment (group 3). Serum TT(4) responses and thyroidal pertechnetate uptake after administration of 25 microg rhTSH IV were assessed. Baseline serum TT(4) was significantly lower in group 3 compared with group 1, but not between other group pairs. Serum TT(4) increased significantly in groups 1 and 2 but not in group 3 after rhTSH administration. Post-rhTSH serum TT(4) concentrations differed significantly between groups 1 and 3 and groups 2 and 3, but not between groups 1 and 2. Thyroid/salivary gland uptake ratio (T/S uptake ratio) differed only significantly between groups 1 and 3. Stimulation with rhTSH is valuable to differentiate euthyroidism from iatrogenic hypothyroidism in cats.

Topics: Animals; Azotemia; Case-Control Studies; Cat Diseases; Cats; Diagnosis, Differential; Female; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Radionuclide Imaging; Recombinant Proteins; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine

Topics: Adolescent; Airway Obstruction; Child; Child, Preschool; Congenital Hypothyroidism; Female; Hormone Replacement Therapy; Humans; Hypothyroidism; Infant, Newborn; Lingual Thyroid; Male; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyrotropin; Thyroxine

Iodide transport defect (ITD) is an infrequent condition associated with congenital dyshormonogenetic goiter due to mutations in the Na(+)/I(-) symporter (NIS) gene transmitted in an autosomal recessive manner. Herein, we describe a patient with ITD and discuss the features important for the diagnosis, focusing on whether or not measuring the saliva/serum radioactive iodide ratio is useful.. A 42-year-old Japanese man attended our hospital in 2010. At that time, he had been off L-thyroxine for several months. He had no obvious mental retardation. His parents were cousins and his sister also had a goiter. Since thyroid dyshormonogenesis could not be ruled out, thyroid function tests, scintigraphy, and ultrasonography were performed. The results showed marked hypothyroidism with a high thyroglobulin level of 627 ng/mL. The results for thyroglobulin antibody and thyroid peroxidase antibody were both negative. Ultrasonography showed an enlarged thyroid gland. Neither the thyroid nor the salivary gland was visualized by (99m)TcO(4)(-) scintigraphy. Therefore, we performed genetic testing for the NIS gene without measuring the saliva/serum radioactive iodide ratio. A homozygous mutation, T354P, was identified in the NIS gene. On the basis of this finding, we could make the definitive diagnosis of ITD due to an NIS mutation.. We recommend confirming the presence of the thyroid by ultrasonography of the neck first and then performing (99m)TcO(4)(-) scintigraphy. If neither the salivary gland nor the thyroid is visualized, screening for NIS mutations should be undertaken. This approach obviates the need to undertake measurement of the saliva/serum radioactive iodide ratio to diagnose ITD.

Topics: Adult; Humans; Hypothyroidism; Iodides; Male; Radionuclide Imaging; Saliva; Sodium Pertechnetate Tc 99m; Symporters; Thyroid Gland; Ultrasonography

This study investigated the thyroidal response to administration of recombinant human thyroid stimulating hormone (rhTSH) by means of serum total thyroxine (TT(4)) concentration and pertechnetate uptake by the thyroid gland in six healthy euthyroid spayed female cats. A pertechnetate scan was performed on day 1 to calculate thyroid/salivary gland (T/S) uptake ratio. On day 3, 25 microg rhTSH was injected intravenously. Six hours later the thyroid scan was repeated as on day 1. Blood was drawn for serum TT(4) measurement prior to injection of rhTSH and performance of the pertechnetate scan. Statistically significant differences in mean serum TT(4) concentration, T/S uptake ratio before and 6h after rhTSH administration and T/S uptake ratio between left and right lobes were noted. We can conclude that 25 microg rhTSH increases pertechnetate uptake in the thyroid glands of cats, this should be taken into account when thyroid scintigraphy after rhTSH administration is interpreted.

Topics: Animals; Cat Diseases; Cats; Female; Hypothyroidism; Radionuclide Imaging; Recombinant Proteins; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine; Time Factors

The exact prevalence and clinical significance of ectopic thyroid or thyroglossal duct remnant (TGDR) in the general population have not yet been fully determined despite numerous case reports. This study was prepared to assess the prevalence of TGDR in asymptomatic subjects during hypothyroidism after a total thyroidectomy for differentiated thyroid cancer (DTC) and to clarify the clinical implication.. Tc-99m pertechnetate scintigraphy (Tc-scan) of the head and neck before radioiodine ablation therapy and whole-body and pinhole I-131 scintigraphy (I-scan) after ablation therapy were reviewed for 131 consecutive DTC patients with hypothyroidism after a total thyroidectomy.. Forty-four among the 131 patients (33.6%) revealed an unexpected linear or focal radioactivity at the anterior midline of the neck, suggesting the presence of TGDR. The Tc-scan and pinhole I-scan were concordant in all cases of abnormal midline neck uptake, although the planar I-scan failed to delineate TGDR due to prominent photon scattering in most cases. Preoperative enhanced neck computed tomography scan was performed in 49 patients and showed no evidence of thyroid glandular tissue separated from thyroid gland in midline of the anterior neck except 1 case. The success rate after radioiodine ablation did not differ significantly between the positive and negative TGDR patients.. TGDR can be frequently observed in scintigraphy of hypothyroid subjects after a thyroidectomy, even when clinically unexpected. Therefore, care should be taken not to confuse the tracer uptake by TGDR with metastatic foci in I- and Tc-scans of patients with hypothyroidism after a thyroidectomy for DTC.

Topics: Adult; Aged; Choristoma; Combined Modality Therapy; Female; Humans; Hypothyroidism; Korea; Lymphatic Metastasis; Male; Middle Aged; Prevalence; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroglobulin; Thyroglossal Cyst; Thyroid Gland; Thyroid Neoplasms; Thyroidectomy; Thyrotropin

The aetiology of congenital hypothyroidism (CH) may be important in determining disease severity, outcome and treatment schedules because athyroid patients need higher treatment doses and close monitoring particularly early in life. The aim of this study was to evaluate thyroid scintigraphy (TS) findings in infants with CH and to determine the relationship of serum TSH and T4 values with thyroid agenesia, in an attempt to identify factors that may detect thyroid agenesia before treatment. Since August 2002 to April 2005, screening program for CH was carried out in the Isfahan University of Medical Sciences and Health Services, Isfahan, Iran. Screening was performed by measuring both the serums T4 and TSH concentration at day 3-7 of birth. Full-term newborns were recalled based on a serum TSH >20 mIU/l or serum T4 < 6.5 microg/dl and premature newborns based on T4 level by weight and TSH level by age. After repeating the laboratory test and clinical evaluation, Tc-99m TS was recommended for all infants with suspected CH before thyroxin replacement therapy. On the basis of Tc-99m TS, the thyroid gland was classified as normal scan, ectopic, goiter and athyrosis. TS results were compared with serum T4 and TSH levels. Of 93 381 newborns screened over a period of nearly 3 years, 262 neonates were found to have CH. The overall incidence of CH was 1 : 357 live births with a female/male ratio (F/M) of 1.4/1. Thyroid scan was performed on 116 (54%) of the infants with CH; of them, 33 cases (28.4%) were athyrotic (F/M = 0.8/1) while seven infants (6%) had ectopic thyroid (F/M = 1.3/1) and 76 cases (65.6%) had a normal thyroid scan (F/M = 1.5/1). Infants with the absence of thyroid in TS had significantly higher TSH value in comparison with those with ectopic or normal TS (116.3 +/- 109.64 vs. 108.10 +/- 62.92 or 55.35 +/- 48.26 mIU/l, respectively, P < 0.0001). Although not statistically different, the mean T4 level was higher in normal TS group than in ectopic and athyrotic groups (8.03 +/- 3.48 vs. 6.36 +/- 5.57 or 5.04 +/- 3 microg/dl, respectively, P = 0.09). We conclude that Tc-99m TS is a useful diagnostic tool for the initial investigation of suspected CH and considering the correlation of TS results with blood TSH levels, proper management and close monitoring of hypothyroid infants with severe hormonal alterations is necessary for the detection of thyroid agenesia.

Topics: Congenital Hypothyroidism; Consanguinity; Female; Humans; Hypothyroidism; Infant, Newborn; Iran; Male; Neonatal Screening; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Dysgenesis; Thyrotropin; Thyroxine

To assess whether the risk of development of hypothyroidism after treatment with iodine 131 (131I) was associated with the pattern of sodium pertechnetate Tc 99m activity in the thyroid gland detected via scintigraphy before treatment in cats with hyperthyroidism.. Retrospective study.. 165 cats.. Medical records of cats with hyperthyroidism that had been treated with 131I (from 1990 to 2002) and had undergone scintigraphy of the thyroid gland before treatment were reviewed; data regarding signalment, scintigraphic findings (classified as unilateral, bilateral-asymmetric, bilateral-symmetric, or multifocal patterns), serum total thyroxine (T4) concentrations before treatment and prior to hospital discharge, and 131I treatment were collected. A questionnaire was sent to each referring veterinarian to obtain additional data including whether the cats subsequently developed hypothyroidism (defined as serum total T4 concentration less than the lower reference limit > or = 3 months after treatment).. 50 of 165 (30.3%) 131I-treated cats developed hypothyroidism. Hypothyroidism developed in 39 of 109 cats with bilateral, 10 of 50 cats with unilateral, and 1 of 6 cats with multifocal scintigraphic patterns of their thyroid glands. Cats with a bilateral scintigraphic pattern were approximately 2 times as likely to develop hypothyroidism after 131I treatment than were cats with a unilateral scintigraphic pattern (hazard ratio, 2.1; 95% confidence interval, 1.04 to 4.2).. Cats with hyperthyroidism that have a bilateral scintigraphic pattern in the thyroid gland before 131I treatment appear to have a significantly higher risk of subsequently developing hypothyroidism, compared with cats with a unilateral scintigraphic pattern.

Topics: Animals; Cat Diseases; Cats; Female; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Male; Radionuclide Imaging; Retrospective Studies; Risk Factors; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Hormones

Thyroid imaging with isotopic iodide (123I) or technetium Tc 99m pertechnetate has been available for decades but is not routinely used in newborn infants diagnosed with congenital hypothyroidism (CH). Among clinicians who believe that presence, absence, or abnormal location of a thyroid does not alter management of CH, imaging is not advocated for anatomic diagnosis of CH.. To define the role of thyroid scintigraphy in diagnosing and managing newborn CH.. Retrospective review of 249 confirmed cases of CH seen at a large, group-model managed care organization during the 24-year period extending from September 1978 through December 2002. Neonatal thyroid scintigraphy was performed in 210 cases (86%): 123I was used in 143 cases (68%), and technetium Tc 99m pertechnetate was used in 67 cases (32%). To perform scintigraphy with 123I, 30 to 50 microCi ([1.11-1.85] x 10(6) Bq) of 123I was administered orally; an uptake image was taken in 3 to 6 hours; and, if necessary, another image was taken in 24 hours. For technetium, 0.5 to 1 mCi ([1.85-3.7] x 10(7) Bq) of technetium Tc 99m pertechnetate was administered intravenously with imaging 20 minutes later. Thyroid dysplasia was defined as an absent or ectopic gland requiring lifetime therapy and eutopic thyroid as a normal-appearing thyroid gland in the proper location but possibly malfunctioning and requiring therapy.. Of the 210 infants with CH receiving scintigraphy, 90 (43%) had eutopic (normal-appearing) thyroid diagnosed, and 120 (57%) had ectopic or absent gland (25% ectopic, 32% absent) diagnosed. Of these 210 infants, ethnicity was known in 198; of these, 76 (38%) were Latino/Hispanic, and 122 (62%) of the infants were non-Latino/non-Hispanic. Prevalence of CH differed between ethnic groups in our population of >700,000 newborn infants; total prevalence of CH was 1 per 3139. Prevalence of CH in Latino/Hispanic infants was highest at 1 per 1750 infants (1:1357 females, 1:2463 males). Prevalence of CH in non-Latino/non-Hispanic infants was 1 per 4648 infants (1:3500 females, 1:6914 males). Given that the total Kaiser Permanente infant population was approximately 19% Latino/Hispanic, the percentage of Latino/Hispanic infants with CH was significantly higher than expected. Dysplastic thyroid was more common in Latino/Hispanic females (69%) than in non-Latino/non-Hispanic females (52%). The female-to-male ratio of patients with CH was 1.9:1. Among the 210 infants with CH, normal thyroid was diagnosed more by 123I scintigraphy (49% of cases) than by scintigraphy using technetium Tc 99m pertechnetate (31% of cases). Use of technetium Tc 99m pertechnetate could have diagnosed dysplastic thyroid in some cases that would be considered eutopic had 123I been used. Eight familial cases of CH were identified.. CH, a heterogeneous disorder with prevalence influenced by familial, ethnic, and gender factors, is more common in Latino/Hispanic females. When present, a eutopic thyroid is more likely to be detected by 123I scintigraphy; this method is therefore preferred over scintigraphy using technetium Tc 99m pertechnetate for optimal management of CH. Parents can then be counseled on either the certainty of lifetime therapy (for dysplastic thyroid) or the possibility of later discontinuing therapy (for eutopic thyroid, because CH may be transient in these children). If the dysplastic thyroid gland is absent or ectopic (usually a small sublingual gland), parents can be told that the infant will need lifetime thyroid therapy. If the thyroid gland is present in the normal position (eutopic) and the condition is transient (as shown by controlled withdrawal of thyroid in older children), lifelong treatment may not be needed. Parents rightly expect this maximal clinical and laboratory information in the immediate newborn period. Some clinicians hesitate to recommend neonatal scintigraphy for children with CH because of concern about delaying L-thyroxine therapy, concern about radiation exposure, or both. We believe that neither concern is warranted. 123I thyroid imaging has been used for many decades without evidence of risk for thyroid cancer. Treatment need not be delayed until scintigraphy is done. We did not use ultrasonography for thyroid imaging because this technique was not available in the early years of our study and may still not have sufficient sensitivity. Sources of discrepancy in our study could include scintigraphy interpreter bias due to lack of objective standards. We cannot estimate the true prevalence of transient CH because not all physicians give children with CH a trial off therapy at 2 to 3 years old, even if a eutopic thyroid is shown by 123I scintigraphy. Because therapy with L-thyroxine is simple and inexpensive and the outcome of untreated CH can be devastating, some parents and physicians are reluctant to discontinue treatment in children with CH, even when scans show a eutopic thyroid. Additionally, the clinical information contained in our database was not detailed enough to enable us to discover all cases of CH in which thyroxine therapy was discontinued. Because the study began in 1978 (>25 years ago), some patients were unavailable for long-term follow-up. In addition to allowing a more rational clinical approach to CH, 123I thyroid sci. Despite data limitations, we believe that neonatal diagnosis of CH represents perhaps the greatest success of newborn screening programs. Initial laboratory diagnosis is simple and sufficiently accurate; treatment is simple, inexpensive, and effective. Severe mental retardation and growth failure can be prevented. Considering today's rapid advances in understanding the basic mechanisms of thyroid embryogenesis and gene abnormalities, thyroid scintigraphy may provide insight into clinical and genetic correlates in CH.

Topics: Choristoma; Congenital Hypothyroidism; Female; Hispanic or Latino; Humans; Hypothyroidism; Infant, Newborn; Iodine Radioisotopes; Male; Neonatal Screening; Radionuclide Imaging; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine; White People

Congenital hypothyroidism is one of the most frequent endocrine diseases of the newborn and requires an early diagnosis to avoid its deleterious effects on neurological and intellectual functions.. To evaluate thyroid scintigraphy (TS) findings in newborns with congenital hypothyroidism (CH), detected in the national program of newborn screening, which is working in Chile since 1992.. TS findings of 189 newborns with CH (68% female) were analyzed. Tc99m pertechnetate TS was performed at 19 +/- 11 days of life. The gland was classified as eutopic, ectopic or absence of contrast (AC). Eutopic glands were classified by visual and quantitative criteria as: normal, goiter and decreased contrast (DC). TS results were compared by gender and hormonal levels.. Forty seven percent of newborns had ectopy, 29.1% eutopy and 24.3% AC. Eutopic gland predominated in males (44.2% vs 22.7%) and ectopy was more frequent in girls (53.1% vs 32.8%, p < 0.05). Newborns with AC had the most severe hormonal alterations, without gender differences. Newborns with normal TS had less hormonal alterations than those with goiter.. TS allows an etiological classification of CH. Thyroid dysgenesis is the most frequent cause, most of which correspond to ectopy, especially in girls. Eutopic glands are present in one third of newborns with CH. Goiter predominates, especially in males.

Topics: Chile; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Neonatal Screening; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland

Dietary iodine intake in Japan varies from as little as 0.1 mg/day to as much as 20 mg/day. The present study was undertaken to assess the frequency of iodine-induced reversible hypothyroidism in patients diagnosed as having primary hypothyroidism, and to clarify the clinical backgrounds responsible for the spontaneous recovery of thyroid functions. Thirty-three consecutive hypothyroid patients (25 women and eight men) with a median age of 52 years (range, 21-77 years) without a history of destructive thyroiditis within 1 year were asked to refrain from taking any iodine-containing drugs and foods such as seaweed products for 1-2 months. The median serum thyrotropin (TSH) level, which was initially 21.9 mU/L (range, 5.4-285 mU/L), was reduced to 5.3 mU/L (range, 0.9-52.3 mU/L) after iodine restriction. Twenty-one patients (63.6%) showed a decrease in serum TSH by >50% and to <10 mU/L. Eleven patients (33.3%) became euthyroid with TSH levels within the normal range (0.3-3.9 mU/L). The ratios of TSH after iodine restriction to TSH before iodine restriction (aTSH/bTSH) did not correlate significantly with titers of anti-thyroid peroxidase antibody and anti-thyroglobulin antibody or echogenicity on ultrasonography, but correlated inversely with (99m)Tc uptake (r = 0.600, p < 0.001). Serum non-hormonal iodine levels, although not correlated significantly with aTSH/bTSH values, were significantly higher in the 21 patients with reversible hypothyroidism than in the remaining 12 patients. TSH binding inhibitor immunoglobulin was negative in all except one weakly positive case. In conclusion, (1) primary hypothyroidism was recovered following iodine restriction in more than half of the patients, and (2) the reversibility of hypothyroidism was not significantly associated with Hashimoto's thyroiditis but with increased (99m)Tc uptake and elevated non-hormonal iodine levels.

Topics: Adult; Aged; Autoantibodies; Female; Humans; Hypothyroidism; Iodine; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland; Thyroid Hormones; Thyrotropin

The authors report an uncommon finding of hot nodule on Tc-99m sodium pertechnetate thyroid scan in three patients with hypothyroidism. Data indicate that hypothyroidism is secondary to Hashimoto's disease (HD). There was a concordant aspect on I-131 scan in two; a nodular discrepancy (cold nodule with I-131) was associated with the highest microsomal antibodies titer. The findings of thyroid scan and ultrasonographic findings indicate that hot nodules may be observed either on initial or advanced stages of HD. Color flow Doppler sonography, showed an absence of internal increase of vascularization. These data suggest that the observed hot nodules correspond to localized hyperplasia of the less diseased portions secondary to chronic stimulation by TSH.

Topics: Adult; Diagnosis, Differential; Female; Humans; Hypothyroidism; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Nodule; Thyroiditis, Autoimmune

Technetium-99m pertechnetate scintigraphy is a well-established technique for diagnosing congenital hypothyroid disease. However, the biodistribution of pertechnetate (TcO4-) in neonates and young infants is not well documented. The purpose of this study was to analyze and document the biodistribution of TcO4- in young infants.. Scintigraphic studies of 31 patients being examined for hypothyroid disease were analyzed. All patients had elevated levels of thyroid-stimulating hormone. Dyshormonogenesis was diagnosed in 7 patients, ectopic thyroid glands in 19, and agenesis in 5.. Images of the neck, chest, and abdomen taken in the anterior and left lateral positions using a low-energy, all-purpose collimator were reviewed. Twenty-six of the patients had no accumulation of the isotope in the salivary glands and 11 had no gastric uptake on either view.. Based on the absence of salivary gland activity in the patients examined, this study suggests that this is a normal finding in infants younger than 3 months. A lateral view of the neck with markers is sufficient to localize the thyroid gland, because any activity in the neck region would belong to the thyroid. Furthermore, poor and variable uptake of the isotope in the stomach may lead to false-negative results, so caution is urged in the use of this tracer in Meckel's scintigraphy in young infants, particularly if the study findings are within normal limits.

Topics: Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant; Infant, Newborn; Male; Radionuclide Imaging; Radiopharmaceuticals; Salivary Glands; Sodium Pertechnetate Tc 99m

The Greek screening program for primary congenital hypothyroidism was initiated in 1979. By early 2000, thyrotropin measurements had been performed in 1,976,719 newborns, using dried blood spots obtained by heel prick. Among these children, 584 were diagnosed with congenital hypothyroidism (incidence: 1/3,384 births) and were given L-thyroxine (L-T4) replacement therapy. In order to further evaluate and classify the children as having either an aplastic (AT) or an ectopic thyroid gland (ET) or as showing thyroidal dyshormonogenesis (DN, with a nomotopic gland), scintigraphic studies were performed at the age of 2-3 years. In 413 children of this age group (including 24 subsequently diagnosed as having had transient hypothyroidism, in whom L-T4 therapy was not resumed), thyroid hormones were measured and scintigraphic studies were done after withdrawal of L-T4 replacement treatment for 3 weeks. Given the long duration of the study, we used various scintigraphic modalities. In 96 children (group A), scintigraphy was performed using technetium-99m pertechnetate (99mTcO4-; 18.5 MBq given i.v.) and a rectilinear scanner. Seventy-three children (group B) were studied with 99mTcO4- (18.5 MBq given i.v.) and a gamma camera equipped with a pinhole collimator. In these groups, atropine was administered 30 min prior to the study (0.02 mg/kg i.v. or i.m.) in order to reduce the secretion of saliva from the salivary glands. Finally, in the remaining 220 children (group C) iodine-123 sodium iodide (123I-Na) (0.74-1.85 MBq i.v.) and the same gamma camera were used. Between-group comparisons of scintigraphic findings were done with the chi square test. In 191 children from group C, thyroglobulin (Tg) was measured and in 49 children ultrasound (US) was performed (categorising the gland as AT or ET/DN). Comparison of these modalities was done with the kappa statistic. In group A, 61.5% of children had AT, 26.0% had ET and 12.5% had DN; in group B, 28.8% of children had AT, 52.0% had ET and 19.2% had DN; in group C, 23.2% of children had AT, 63.2% had ET and 13.6% had DN. Statistically significant differences in group A versus groups B and C were noted for AT and ET. The implementation of newer scintigraphic modalities, and especially the use of 123I-Na, indicates that the commonest finding in congenital hypothyroidism is ET. Scintigraphy was more concordant with Tg measurements (though at a moderate level) than with US. The latter was even less concordant with Tg values. T

Topics: Child, Preschool; Congenital Hypothyroidism; Female; Greece; Humans; Hypothyroidism; Iodine Radioisotopes; Male; Mass Screening; Neck; Paraneoplastic Endocrine Syndromes; Radionuclide Imaging; Radiopharmaceuticals; Sodium Iodide; Sodium Pertechnetate Tc 99m; Thyroglobulin; Ultrasonography

Primary congenital hypothyroidism (PCH) is currently detected effectively by heel-stick screening. When elevated thyrotropin (TSH) and/or decreased T4 are found in the blood of neonates, they are recalled, values are confirmed in venous blood and thyroxine replacement therapy (TRT) is immediately instituted, thus cretinism or severe retardation is prevented. However, in a significant percentage of neonates with abnormal blood levels of T4 or TSH, the disorder is transient. To help determine the exact cause of PCH and the possibility of transient PCH, pinhole thyroid imaging is performed 30 min after an intravenous injection of 18.5 MBq (500 microCi) 99mTc-pertechnetate (TcPT). Patients with a nonvisualized gland or patients with images suggesting dyshormonogenesis are reevaluated at age 3-4 y to exclude transient PCH.. To define the role of TcPT imaging in determining the exact etiology of PCH and the possibility of its being transient, we reviewed data from 103 neonates with PCH who had scintigraphy in our laboratory between 1970 and 1996 and we correlated the results with clinical outcome.. Four patterns of thyroid scintigrams were recognized and these determined patient classification: (a) normal in 7 patients with false-positive heel-stick screening but normal venous blood hormone levels; (b) hypoplasia-ectopia in 32 patients requiring lifelong TRT; (c) nonvisualization in 35 patients-32 with agenesis requiring lifelong TRT and 3 with fetal thyroid suppression by maternal antibodies whose TRT was discontinued at a later age; and (d) dyshormonogenesis (markedly increased TcPT concentration) in 29 patients-25 with permanent PCH requiring lifelong TRT and 4 with transient PCH in whom TRT was discontinued. Of the 25 patients with dyshormonogenesis, 12 belonged to five families with two or three siblings having the same disorder.. TcPT thyroid scintigraphy in the neonate with PCH provides a more specific diagnosis, is useful for selecting patients for re-evaluation to uncover transient PCH and discontinue TRT and defines dyshormonogenesis, which is familial and requires genetic counseling. It is also cost-effective.

Topics: Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Neonatal Screening; Radionuclide Imaging; Radiopharmaceuticals; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine

Two sisters who presented with midline neck masses proved to be biochemically hypothyroid. Thyroid scintigraphy supplemented with perchlorate discharge testing showed lingual thyroid glands and ruled out the expected autosomal recessive organification defect. The related literature is reviewed.

Topics: Adult; Child; Choristoma; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland; Tongue Diseases

A girl with Williams syndrome (WS) presented with elevated thyrotropin (TSH) levels (7.0 microU/ml), normal free thyroid hormone concentrations, and absent antithyroid autoantibodies. Thyroid ultrasonography and scintigraphy showed hemiagenesis of the left lobe and no evidence of ectopic tissue. TSH response to thyrotropin-releasing hormone (TRH) injection (200 microg/mq, i.v.) was exaggerated and prolonged, suggesting subclinical hypothyroidism. The biological activity of circulating TSH was slightly below the normal range [TSH bioactivity (B) to immunoreactivity (I) ratio (TSH B/I) = 0.4, normal: 0.6-2.2]. These abnormalities are similar to those seen in patients with hypothalamic hypothyroidism. Thyroid function is not a recognized manifestation of WS and is not routinely investigated. However, abnormalities of the hypothalamic-pituitary-thyroid (HPT) axis and thyroid dysgenesis have been found in other WS cases. Genes mapping at 7q11.23, contiguous to the chromosomal region deleted in most WS patients, may be involved in the development of the thyroid gland, contributing to the complex phenotype of WS.

Topics: Adult; Aging; Chromosome Mapping; Chromosomes, Human, Pair 7; Female; Follow-Up Studies; Humans; Hypothyroidism; Infant; Male; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyrotropin-Releasing Hormone; Thyroxine; Triiodothyronine; Williams Syndrome

A case of Plummer's disease that spontaneously progressed to hypothyroidism is presented. A 49-year-old female visited our hospital because of a 3 kg decrease in body weight during the previous month and a painless nodule in the right anterior area of her neck. A diagnosis of Plummer's disease was made based on the results of thyroid function tests, thyroid scintigrams, and an ultrasonogram, but the patient's disease followed an usual clinical course. About two months later, she gradually developed manifestations of permanent hypothyroidism, and anti-thyroid autoantibodies became positive. In spite of continuous administration of levothyroxine sodium, uptake of 99mTcO4- to the nodule was unchanged or rather increased according to the consecutive thyroid scintigraphies. These results suggested that this case represented an autonomously functioning nodule with underlying silent thyroiditis and Hashimoto's disease.

Topics: Autoantibodies; Disease Progression; Female; Goiter, Nodular; Humans; Hypothyroidism; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid (USP); Thyroid Gland; Thyrotropin; Thyroxine; Triiodothyronine; Ultrasonography

The presence or absence of thyroid glandular tissue demonstrated by thyroid scintigraphy is important for genetic and prognostic counseling and for acceleration of diagnosis in other affected siblings. Technetium-99m-pertechnetate thyroid scintigraphy was performed on 27 children with cretinism at the Division of Nuclear Medicine, Faculty of Medicine Siriraj Hospital during the 5-year period from June 1991. Based on scintigraphic findings, three main groups of thyroid localization were seen. Thirteen (48.1%) were athyrotic while 3 (11.1%) had an ectopic thyroid and 11 (40.8%) had gland in normal position. Perchlorate discharge test was performed in 8 children of the last group and the results were positive indicating an organification defect. Thyroid scintigraphy and perchlorate discharge test provided the useful information for diagnosis, follow-up, and prognosis in children with cretinism.

Topics: Adolescent; Child; Child, Preschool; Congenital Hypothyroidism; Female; Follow-Up Studies; Humans; Hypothyroidism; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland

Thyroid gland ectopy is the most common cause in infants with congenital hypothyroidism (CH). Its association with iodine organification defect, as suggested by positive perchlorate discharge test (PDT) has been reported. However, whether such an association represents a true or transient defect has not yet been determined. This finding has an important clinical, epidemiological, and genetic implications.. To determine the natural history of iodine organification defect in patients with CH caused by thyroid ectopy detected by neonatal screening.. Prospective longitudinal study.. King Khalid University Hospital, Riyadh, Saudi Arabia.. PDT was performed, at the time of diagnosis and follow-up, in infants who showed an enlarged ectopic thyroid gland with a Tc-99m pertechnetate uptake of 2% or more.. Of 115 neonates with ectopic thyroid glands, 19 showed an enlarged gland with Tc-99m uptake ranging from 2 to 3.2%. Perchlorate discharge test was performed in 13 of these and was consistent with iodine organification defect in nine. Repeated PDT in seven patients showed normal values.. The results of the authors' study indicate the transient nature of the iodine organification defect and suggest that a delay in the developmental of synthetic mechanisms occur in the dysgenetic glands.

Topics: Choristoma; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Neonatal Screening; Perchlorates; Potassium Compounds; Prospective Studies; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland; Tongue Diseases

Topics: Choristoma; Female; Humans; Hypertrophy; Hypothyroidism; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland

The aim of this study is to investigate the value of Tc-99m tetrofosmin (Tc-99m-TF) in conjunction with conventional Tc-99m-pertechnetate (Tc-99m-P) scintigraphy in the differentiation of malignant nodules from benign thyroid nodules. Forty-two patients [(32 females, 10 males; mean age 41 +/- 13 years; twenty-two multinodular goiter (MNG) patients with 58 nodules and 20 solitary thyroid nodules (STN)] were included in the study. Thyroid scintigraphy with Tc-99m-P and Tc-99m-TF, thyroid ultrasonography and fine needle aspiration cytology (FNAC) were performed. After i.v. injection of 370-550 MBq Tc-99m-TF, images were obtained at 15 minutes and evaluated semiquantitatively by using a five point (0-4) scoring system. Four patients with a hypoactive STN, and 1 patient with a hypoactive MNG was found to have thyroid malignancy by histopathological examination; 2 of these patients had false negative benign FNAC results. The tetrofosmin uptake score (TUS) was 2-3-3-3 and 3 in these 5 malignant nodules. Five hyperactive (hot or warm) STN with benign FNAC had a TUS of 2-3-3-3-3. All hypoactive (cold) MNG nodules with benign FNAC (n = 21) had TUS < or = 2. Our preliminary results suggest that follicular adenomas and thyroid cancers have higher tetrofosmin uptake than benign colloidal goiter nodules. Mitochondrial sequestration of tetrofosmin in benign or malignant follicular cells that proliferate more rapidly than normal follicular cells and/or hypervascularity may be responsible for this. The use of Tc-99m-TF in conjunction with Tc-99m-P thyroid scintigraphy will be helpful in the evaluation of patients with nodular goiter (NG). In patients with a STN, a hypoactive nodule with a high TUS has a higher probability of malignancy; whereas a hyperactive nodule with a high TUS is a follicular adenoma. In patients with MNG, a hypoactive nodule with a high TUS may be suggestive of malignancy despite a benign FNAC result. We think that further studies with Tc-99m-TF are required to confirm these results.

Topics: Adult; Biopsy, Needle; Diagnosis, Differential; Female; Goiter, Nodular; Humans; Hypothyroidism; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Neoplasms

Atrial fibrillation (AF) and primary hypothyroidism are most often diagnosed in middle-aged and older dogs of large and giant breeds. We hypothesized that the frequency of primary hypothyroidism may be higher in dogs with AF than in those without AF. Two groups were investigated. Group 1 (March 1987-June 1990) consisted of 128 dogs with AF. A thyroid-stimulating hormone (TSH) stimulation test was performed in dogs with a low voltage on the ECG and low uptake of pertechnetate on a thyroid scan. Group 2 (July 1990-July 1991) consisted of both dogs with AF (n = 38) and control dogs (n = 235) in which plasma thyroxine (T4) was measured. If T4 was below 15 nmol/l, a TSH stimulation test was performed. The frequencies of primary hypothyroidism in group 1 (8/128) and in the group 2 AF dogs (3/38) were not different, but were higher than in the control animals (3/235) (P < 0.05). The group 1 and the group 2 AF dogs were found to be comparable, and pooling of the data of the two groups enhanced the significance of the frequency of primary hypothyroidism in dogs with AF versus the control animals (11/166 versus 3/235) (P < 0.01). We concluded that the frequency of primary hypothyroidism in dogs with AF is higher than in the group of control dogs without AF. This may be due to the additional cardiovascular changes accompanying primary hypothyroidism in dogs that already have heart disease.

Topics: Animals; Atrial Fibrillation; Cardiovascular Physiological Phenomena; Cardiovascular System; Dog Diseases; Dogs; Electrocardiography; Female; Hypothyroidism; Incidence; Male; Sodium Pertechnetate Tc 99m; Thyrotropin; Thyroxine

We report herein a case of amyloid goiter associated with rheumatoid arthritis in which hypothyroidism was observed. A 52-year-old housewife who had suffeed from rheumatoid arthritis for 15 years was referred to our hospital because of general fatigue. On admission, a large goiter was observed. Laboratory data showed primary hypothyroidism. Renal biopsy and gastric mucosa biopsy showed amyloid deposition of AA-type. Thyroid biopsy showed massive amyloid involvement. Although the findings of iodine-123 scintigraphy, technetium-99m pertechnetate scintigraphy, computed tomography and magnetic resonance image studies were similar to those for goiter associated with chronic thyroiditis, tallium-201 chloride scintigraphy gave a differing result, demonstrating absent uptake at 3 hours in this case. Replacement therapy with levothyroxine relieved the symptoms. This case was unusual in that amyloid goiter presented clinically as hypothyroidism. Absence of tallium-201 chloride uptake at 3 hours may be a diagnostic specificity for amyloid goiter in differentiating its hypothyroidism from that caused by chronic thyroiditis.

Topics: Amyloid; Female; Goiter; Humans; Hypothyroidism; Magnetic Resonance Imaging; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thallium Radioisotopes; Thyroid Gland; Tomography, X-Ray Computed; Ultrasonography

Topics: Child, Preschool; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Perchlorates; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland

Quantitative thyroid scanning using low doses of technetium-99m sodium pertechnetate was performed on 147 infants (55 males and 92 females) with congenital hypothyroidism detected through the national neonatal screening programme. Thirty-two (21.8%) were athyrotic, while 62 (42.2%) had an ectopic thyroid and 53 (36%) had a eutopic gland with increased 99mTc uptake (mean 17%; range, 5%-38%). The perchlorate discharge test (PDT) was performed in nine of the infants with ectopic glands and 15 with eutopic glands; the findings were consistent with an organification defect in 22 cases (seven ectopic and 15 eutopic). Thyroid scintigraphy and PDT can add useful aetiological, genetic and prognostic information in the clinical evaluation of infants with congenital hypothyroidism detected by neonatal screening.

Topics: Choristoma; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Iodine Radioisotopes; Male; Neonatal Screening; Perchlorates; Potassium Compounds; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland

To determine the clinical utility of cervical ultrasound in patients suspected of having congenital hypothyroidism.. Thirty-seven patients with suspected congenital hypothyroidism underwent ultrasound and scintigraphic evaluation of the thyroid anatomy, morphology, and function. The ultrasound findings and laboratory data were compared with the standard-of-reference scintigraphic findings and laboratory data for diagnosing specific causes in those patients, and prognosis was correlated with the ultrasound findings.. Ultrasound was not reliable for detecting ectopia (n = 8) or differentiating ectopia from aplasia (n = 1). Ultrasound showed ectopia in six (four in the mouth floor and two in the tongue base) of eight cases (75% sensitivity). Ultrasound did not show one ectopia in the floor of mouth because its echogenicity was similar to that of surrounding tissues. A second ectopia, in the hypopharynx, was missed because of hindrance of the laryngeal air. Radioactive iodine uptake and scintigraphy was required for the patients with enlarged glands in the normal place to differentiate dyshormonogenesis from other categories. Specific causes were diagnosed correctly with ultrasound findings and laboratory data alone in all of the 20 patients who had hemiaplasia or small or normal-size glands in the normal location. Incidences of heterogeneity and hypoechogenicity of the thyroid gland in patients with prolonged clinical course (whose replacement therapy or follow-up extended for more than 1 year) were significantly higher than those in patients with short clinical course.. Ultra-sound can obviate the need for scintigraphy in more than half (54%) of patients with possible congenital hypothyroidism. Ultrasound has a potential to predict prognosis of these patients.

Topics: Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant; Infant, Newborn; Male; Neonatal Screening; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine; Ultrasonography

Topics: Adenoma; Adult; Choristoma; Female; Humans; Hypothyroidism; Parathyroid Neoplasms; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thallium Radioisotopes; Thyroid Gland; Tongue Diseases

The present study was designed to analyse the scintigraphic appearance of the thyroid in hypothyroid patients with blocking-type TSH receptor antibodies (TRAbs). Eleven hypothyroid patients with autoimmune thyroiditis positive for TSH binding inhibitor immunoglobulins (TBII) [80% +/- 12 (SD)%; normal < 11%] and for thyroid stimulation-blocking antibodies (TSBAbs) (90% +/- 9%: normal < 32%) were studied. Thyroid scanning was performed using technetium-99m or iodine-123, when the patients were hypothyroid. Analysis of the scan images revealed the presence of localized functioning areas in six patients (group 1), and no visualization of the thyroid in the remaining five patients (group 2). Patients in group 1 showed significantly higher uptake of 99mTc than those in group 2 (P < 0.05). Interestingly, three patients in group 1 were positive for thyroid-stimulating antibodies (TSAbs) (249% +/- 17%; normal < 145%), which were not detected in the remaining eight patients. Antibodies against thyroglobulin and microsomal antigens were detected in nine nine (81.8%) and 11 (100%) patients, respectively, but neither of these titres correlated with the scan image. Three patients in group 1 underwent scintigraphy again after treatment with thyroxine, at which time the functioning lesion was not noted. Fourteen hypothyroid patients with negative TBII displayed no such scintigraphic findings. Chronic stimulation of the thyroid by TSAbs and/or TSH might be responsible for the presence of the functioning lesion, but clarification of the mechanism requires further studies. In summary (1) TSAbs were detected in three (27.3%) of 11 hypothyroid patients with blocking TRAbs; (2) thyroid scintigraphy revealed the presence of localized functioning area(s) in approximately half of these cases.

Topics: Adolescent; Adult; Aged; Binding, Competitive; Female; Humans; Hypothyroidism; Immunoglobulins, Thyroid-Stimulating; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Receptors, Thyrotropin; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroiditis, Autoimmune; Ultrasonography

Topics: Child, Preschool; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant; Infant, Newborn; Male; Radionuclide Imaging; Retrospective Studies; Salivary Glands; Sodium Pertechnetate Tc 99m; Thyrotropin; Thyroxine

Serum thyroglobulin (Tg) data are presented for 47 infants with congenital thyroid disorders. Abnormal elevation of serum Tg (> 250 micrograms/L) occurred in 17% of the population studied, whereas values in excess of 1,000 micrograms/L were demonstrated in 11% of infants. The latter group includes the first report of supraphysiologic Tg elevation in an infant with thyroid gland ectopia, and the highest reported thyroglobulin level in the syndrome of generalized thyroid hormone resistance in an infant homozygous for a novel deletion in the c-erbA beta receptor. Mechanisms involved in the pathogenesis of Tg elevation are discussed. We conclude that Tg elevation in congenital thyroid disorders is more common than previously recognized, and values > 1,000 micrograms/L identify infants with a spectrum of anatomic and biochemical abnormalities.

Topics: Congenital Hypothyroidism; Humans; Hypothyroidism; Infant; Infant, Newborn; Radionuclide Imaging; Reference Values; Sodium Pertechnetate Tc 99m; Thyroglobulin; Thyroid Diseases; Thyroid Hormones

Technetium-99m pertechnetate thyroid scans were generally applied to patients with thyroid diseases including hypothyroidism. We reviewed the thyroid images of 126 neonates who were suspected to have congenital hypothyroidism by neonatal TSH screening and of 2 cases by clinical suspicion. Of these, 62 cases were of transient hyperthyrotropinemia or were normal. Twenty-nine cases were of ectopic thyroid (M:F = 9:20). Two cases were hemiagenesis, both were female. Eight cases were athyrosis (M:F = 4:4). Two cases were secondary hypothyroidism (M:F = 1:1). Twenty-five cases were eutopic hypothyroidism (M:F = 13:12). We considered that the Tc-99m thyroid scan is convenient and useful in the differential diagnosis of the etiology of congenital hypothyroidism.

Topics: Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant; Infant, Newborn; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland

Thyroid scintigraphy was performed in 69 consecutive infants with permanent primary congenital hypothyroidism (CH) detected by systematic neonatal thyroid screening using a rectilinear scanner or a gamma camera 15 minutes after the intravenous injection of 250 microCi Tc-99m sodium pertechnetate, immediately after the infants were fed. Immobilization of the infant in a supine position with the neck in hyperextension was achieved by a vacuum cushion without any sedation. Thyroid scintigraphy showed thyroid ectopia in 43 of the 69 CH infants, thyroid agenesis in 19, and goiter in the last 7 infants, respectively. The images were easily interpretable in all cases, even in very small ectopic glands in the lingual area, as there was no interference with extra-thyroidal uptake of the tracer, especially by the salivary glands. Our experience indicates that thyroid scintigraphy in the CH newborns can be performed immediately at the time of diagnosis of CH without technical difficulties. As thyroid scintigraphy is the only procedure allowing the distinction between thyroid agenesis and ectopia, and as the neurointellectual prognosis might be lower in the former than in the latter situation, thyroid scintigraphy in CH newborns contributes not only to the diagnosis but also the prognosis of the disorder.

Topics: Choristoma; Congenital Hypothyroidism; Humans; Hypothyroidism; Infant, Newborn; Neonatal Screening; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Tongue Neoplasms

Fifty-four neonates with congenital hypothyroidism identified by the North East and North West Thames Regional hypothyroid screening programme between January 1985 and December 1987 were investigated with radioisotope (Tc99m) and ultrasound scans of the thyroid before treatment with 1-thyroxine was commenced. Compared with the radioisotope scans, ultrasound identified normally sited thyroid tissue in only 7 out of 10 cases, and ectopic thyroid tissue in only 5 out of 26 cases. Three out of 18 cases with no isotope uptake in the neck appeared to have normally sited tissue on ultrasound scan. We conclude that in our hands ultrasound of the neck is of only limited value in the assessment of young infants with congenital hypothyroidism.

Topics: Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Ultrasonography

This paper describes diminished concentration of Tc-99m pertechnetate in the salivary glands of infants with congenital hypothyroidism. The salivary glands' abnormalities were incidentally noted on the neck images acquired for suspected lingual thyroid or athyrosis. None of the 11 infants with congenital hypothyroidism revealed normal Tc-99m pertechnetate trapping in the salivary glands.

Topics: Congenital Hypothyroidism; Humans; Hypothyroidism; Infant; Infant, Newborn; Radionuclide Imaging; Retrospective Studies; Salivary Glands; Sodium Pertechnetate Tc 99m; Thyroid Gland

99mTc-pertechnetate uptake was estimated 8-13 weeks after radioiodine therapy for hyperthyroidism in 132 patients in order to evaluate the usefulness of the uptake test in predicting both persisting hyperthyroidism and the early onset of hypothyroidism during the first year after therapy. The estimation was simple, the result immediately available, and its sensitivities, positive predictive value and its overall accuracy (83%) compared favourably with that of in-vitro tests, FT4I (75%) and FT3I (80%), carried out on the same occasions during the early follow-up period. Pertechnetate uptake can be a useful guide to management by promptly identifying patients likely to need further radioiodine therapy and those with transient or permanent hypothyroidism. The study confirmed some previous findings that hypothyroidism was more frequent in patients with thyroid antibodies and less frequent in patients with nodular thyroids, and it also indicated that hypothyroidism was more frequent in those treated with carbimazole before and after radioiodine, and that hyperthyroidism was more likely to persist in those treated with carbimazole before or after radioiodine.

Topics: Follow-Up Studies; Humans; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Prognosis; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Unlike radionuclide scanning (RNS) ultrasound investigation (USI) permits thyroid volume estimation in hyperplasia and euthyroid goiter. USI in nodular goiter gives an opportunity to reveal the sizes of a tumor, its macrostructure, topographic position with regard to the neck organs and vessels and is a method of choice in autoimmune thyroiditis. A considerable advantage of USI is a possibility to characterize the thyroid collateral lobe in toxic adenoma and to perform investigations over time. A positive feature of RNS is a possibility for differential diagnosis of "hot" and "cold" nodes of the thyroid, metastases to other organs and atypical localization of the gland.

Topics: Adult; Female; Goiter, Nodular; Graves Disease; Humans; Hyperplasia; Hypothyroidism; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Diseases; Thyroid Gland; Thyroiditis, Autoimmune; Ultrasonography

This study prospective without any selection bias included 80 of the 152 hypothyroid infants and children seen over the past six years. The clinical diagnosis was confirmed by TSH and thyroid hormone (T3, T4) studies. Scanning for thyroid with TC99m pertechnetate was carried out in all except seven older children with grade II and III goiters where 131I uptake studies were done. Serum thyroglobulin (RIA) was estimated and antithyroglobulin and antimicrosomal antibodies were tested. Based on thyroid 131I scan or 131I uptake, 52.5% had no demonstrable thyroid tissue except one with hypoplasia (Group I, n = 42), 25% had ectopic thyroid (Group II, n = 20), and 22.5% had normal or enlarged thyroid gland (Group III, n = 18). One hypothyroid patient of Group III had thyroiditis with high antibody titre and one was proved to have iodine deficiency). The mean age at time of diagnosis was lowest in Group I (age in months--30.3 +/- 36.2; 60.6 +/- 53.9; 106.2 +/- 69.3 in Groups I, II and III respectively. The intergroup differences in age were significant. The mean serum Tg levels increased progressively from Groups I to III. In the present series thyroid dysgenesis led to hypothyroidism in 77.5%, with athyreosis in 52.5% and ectopia in 25%. Dyshormonogenesis was noted in 20% and thyroiditis in 1.5%.

Topics: Adolescent; Age Factors; Child; Child, Preschool; Humans; Hypothyroidism; Infant; Iodine Radioisotopes; Prospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Hormones

Topics: Humans; Hydroxyquinolines; Hypothyroidism; Iodoquinol; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Quantitative Tc-99m pertechnetate thyroid imaging was performed on a hypothyroid neonate. The image revealed markedly increased trapping in an enlarged, bilobed, eutopic gland. A perchlorate washout test using quantitative imaging with I-123 confirmed an organification problem.

Topics: Congenital Hypothyroidism; Humans; Hypothyroidism; Infant, Newborn; Iodine Radioisotopes; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Forty-one infants have been referred for thyroid scintigraphy following routine screening for congenital hypothyroidism: 14 (35%) were athyreotic, 19 (45%) had an ectopic thyroid, four (10%) were normal and four (10%) demonstrated other abnormalities. There was a female: male ratio of 4:1. Thyroid scintigraphy is a useful adjunct to biochemical screening.

Topics: Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Mass Screening; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Two cases of congenital defect in iodide trapping mechanism are related. The absence of thyroid and gastric concentration of 99mTcO4 led to the diagnosis. The study of saliva and gastric:serum concentration ratios confirmed the complete defect. The kinetics of radioiodine studied by external detection showed an early simultaneous decay in the thyroid, the stomach and the left ventricle. Thyroid accumulation of 131I, demonstrated by camera imaging, was estimated to be 0.1% at 48 h. It probably originated from simple diffusion. Iodide supplementation was progressively increased to 4.5 g and 10 g day-1 respectively. It resulted in a normalization of all parameters. Huge doses of iodide did not result in any evidence of hyperthyroidism as TSH rose normally after TRH. Intermittent iodide supplementation in one case could not maintain euthyroidism longer than a few weeks. Daily treatment, therefore, seems necessary.

Topics: Adolescent; Child, Preschool; Congenital Hypothyroidism; Female; Gastric Juice; Humans; Hypothyroidism; Iodides; Iodine Radioisotopes; Kinetics; Male; Saliva; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine; Triiodothyronine

Iodine excess is associated with a low thyroidal radioiodine uptake due to dilution of the radioisotope by the increased stable iodide pool. We studied thyroidal uptake of radioisotopes in cardiac patients with iodine excess due to amiodarone treatment. 99mTc-pertechnetate scintigraphy was performed in 13 patients receiving long term amiodarone therapy. Five patients had a clearly visible thyroid gland, and 8 patients had no or a very faint thyroid image. All patients with positive scans had an increased plasma TSH level, whereas all patients with negative scans had a normal or absent TSH response to TRH. Thyroidal uptake and discharge of 123I were studied in 30 other patients. Group I (n = 11) had normal plasma TSH responses to TRH and no iodine excess, group II (n = 7) had normal TSH responses to TRH and excess iodine from metrizoate angiography in the previous month, group III (n = 7) had normal or decreased TSH responses to TRH while receiving long term amiodarone therapy, and group IV (n = 5) had increased TSH responses to TRH while receiving long term amiodarone therapy. The mean radioiodine uptake value in group I [5.4 +/- 0.8% (+/- SE) at 60 min] was higher than those in group II (2.3 +/- 0.7%; P = 0.009) and group III (0.8 +/- 0.3%; P = 0.0005), but not different from that in group IV (5.3 +/- 1.2%; P = NS). Radioiodine discharge after perchlorate (expressed as a percentage of the 60 min uptake) in group I (10.1 +/- 2.2%) was lower than those in group II (24.9 +/- 10.6%; P = 0.05) and group III (28.8 +/- 5.3%; P less than 0.005), whereas discharge in group IV (58.0 +/- 6.1%) was greater than those in group II (P less than 0.05) and group III (P less than 0.01). In conclusion, 1) thyroid visualization by 99mTc-pertechnetate and thyroid radioiodine uptake during iodine excess are decreased in euthyroid and hyperthyroid patients, but preserved in hypothyroid patients. 2) The organification defect induced by iodine excess is greater in iodide-induced hypothyroidism than in eu- or hyperthyroidism. These findings may be explained by the increased TSH secretion in hypothyroidism and/or by decreased thyroidal concentration of an unknown specific iodinated compound (whose concentration and action vary with the total organic iodine content of the thyroid) that mediates the inhibition of iodide transport.

Topics: Adult; Aged; Amiodarone; Benzofurans; Female; Humans; Hypothyroidism; Iodine; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland

Topics: Humans; Hyperthyroidism; Hypothyroidism; Sodium Pertechnetate Tc 99m; Thyroxine; Triiodothyronine

Technetium 99m pertechnetate thyroid scans were performed on 57 infants referred for evaluation of suspected congenital hypothyroidism. Thyroid anatomy may be characterized by four general types, based on the scintigraphic findings: (1) normal size and location; (2) ectopic location; (3) no detectable thyroid activity; (4) normal location with increased size or uptake. There are diverse etiologies of congenital hypothyroidism. Correlation of thyroid scintigraphy with blood T4 and TSH levels allows specific etiological diagnosis in the majority of cases of congenital hypothyroidism.

Topics: Choristoma; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Mass Screening; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Hormones; Thyrotropin; Tongue Neoplasms

Thyroid function and thyroid gland volume, ultrasonically determined, were investigated in 27 hyperthyroid patients with solitary autonomous thyroid nodules before and during one year after 131I-treatment. Total thyroid volume decreased gradually from 40.9 +/- 3.5 ml (mean +/- SEM) before treatment to 23.9 +/- 1.8 ml (P less than 0.001) at 3 months after 131I-treatment. No further change was observed. All but two patients received only one dose of 131I, and in spite of a significant decrease also of the non-adenoma side of the gland, none became hypothyroid. We conclude that 131I-therapy has an important place in the treatment of solitary autonomous thyroid nodules since all our patients became euthyroid within 3 months, only 2 of 27 patients needed more than one dose of 131I, no cases of hypothyroidism occurred, and thyroid volume was substantially decreased.

Topics: Adenoma; Adult; Aged; Female; Follow-Up Studies; Humans; Hypothyroidism; Iodine Radioisotopes; Male; Middle Aged; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland; Thyroid Neoplasms

Thyroid dysgenesis is often manifested by a lingual or sublingual location of the thyroid gland. If radionuclide studies are not readily available or are contraindicated, ultrasound (US) may be used to locate the gland. The US appearance of a lingual thyroid gland and the role of US in the evaluation of suspected thyroid dysgenesis are described.

Topics: Child; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Tongue; Ultrasonography

It has been established that chronic hypothyroidism may affect cardiac function by several mechanisms. It is not known how long the patient has to be hypothyroid for cardiac involvement to develop. This study was undertaken to assess the effect of a short period of hypothyroidism (10 days) on cardiac function. Nine patients who had had total thyroidectomy, had received ablative radioiodine for thyroid cancer and were euthyroid on replacement therapy were studied while both euthyroid and hypothyroid. Cardiac assessment was performed by X-ray, ECG, echocardiography and gated blood-pool scans. After 10 days of hypothyroidism, the left-ventricular ejection fraction failed to rise after exercise in 4 of the 9 patients studied, which was significant (P less than 0.002). No significant changes in cardiac size or function at rest were detected. This functional abnormality in the absence of any demonstrable change in cardiac size and the absence of pericardial effusion with normal basal function suggest that short periods of hypothyroidism may reduce cardiac reserve, mostly because of alterations in metabolic function.

Topics: Acute Disease; Adult; Electrocardiography; Female; Heart; Humans; Hypothyroidism; Male; Middle Aged; Physical Exertion; Radioimmunoassay; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Thyroid Hormones; Thyroidectomy

Seventeen patients, screened from a neonatal programme for hypothyroidism were studied. As well as the scintigraphic investigations, serum TSH, T3, free T3, T4, free T4, and TBG were measured in all patients. Not more than 11.1 MBq (300 microCi) 99mTcO4- was administered IV. A gamma camera with a parallel-hole collimator on line with the computer was used. The method allowed good statistics to be obtained in 5-10 min in a wide field of exploration, thus reducing the problems of positioning and prolonged immobilization of the young patient. The data collected in the computer were elaborated to define better the characteristics of the thyroid image. This kind of in vivo study introduced into a screening programme, enables an 'anatomic' diagnosis of the defect to be obtained before starting the therapy. This is undoubtedly valuable from the epidemiological point of view, enables early determination of the degree of thyroid insufficiency, and contributes to the formulation of a prognosis based on the degree and on the moment in which prenatal harm occurred.

Topics: Computers; Congenital Hypothyroidism; Female; Humans; Hypothyroidism; Infant, Newborn; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Hormones

Tumor risk factors were calculated for newborns who were investigated for congenital hypothyroidism (CHT) with radionuclides by thyroid scintigraphy. Figures for three radiopharmaceuticals, 99mTc-pertechnetate, 123I-and 131I-sodium iodide for adults were extrapolated to newborns. The radiation dose to the normal thyroid gland in newborns was seven times higher for 123I-NaI than for 99mTcO-4, the somatically effective total body dose was two times higher for 123I-NaI than for 99mTcO-4. The use of 123I-NaI was preferred because of better scintigraphic results. Risk estimates for thyroid scintigraphy in newborns in the diagnostic work-up of CHT are given using published age-dependent tumor induction figures derived from atomic bomb survivors.

Topics: Congenital Hypothyroidism; Humans; Hypothyroidism; Infant, Newborn; Iodine Radioisotopes; Neoplasms, Radiation-Induced; Radiation Dosage; Radionuclide Imaging; Risk; Sodium Pertechnetate Tc 99m; Technetium; Thyroid Neoplasms

An 11-year-old dog was diagnosed as having concurrent unilateral follicular thyroid carcinoma and hypothyroidism. Radioisotope imaging with technetium 99m as sodium pertechnatate identified the extent of thyroid tissue involvement. A combination of surgical resection and hormonal supplementation resulted in a favorable clinical response.

Topics: Adenocarcinoma; Animals; Dog Diseases; Dogs; Hypothyroidism; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Thyroid Neoplasms

Quantitative thyroid scanning using low doses of 99mTc sodium pertechnetate (1.85-3.7 MBq) was performed in 38 cases of congenital hypothyroidism. Of these 38 cases, 29 were scanned at 14 +/- 6 days old, and 9 at 1 year old. The scans show the full range of gland anatomy from athyreotic to normal. All morphologically normal scans had grossly increased uptakes of 99mTc. The incidence of the various thyroid anatomies was different in each age group. The average radiation dose to the thyroid was 2.29 mGy, with at least 70% of patients receiving a dose of 3.0 mGy or less. Such low doses of 99mTc should allow further scanning in later life. Neonatal thyroid scanning reveals the aetiology of congenital hypothyroidism and enables the clinician to assess the short- and long-term needs of the child.

Topics: Congenital Hypothyroidism; Humans; Hypothyroidism; Infant; Infant, Newborn; Methods; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium

Three children with goitrous hypothyroidism had thyroid scans with [Tc-99m] sodium pertechnetate, which showed symmetrically enlarged thyroid glands with uniformly increased activities compared to little activities in the salivary glands and low body background activities. These scan findings, simulating those of Graves' disease, reflect acid trapping of this tracer, analogous to that seen with I-131. Perchlorate discharge test was positive in two patients, indicating an organification defect.

Topics: Adolescent; Child; Congenital Hypothyroidism; Female; Goiter; Humans; Hypothyroidism; Infant, Newborn; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Thyrotropin

Topics: Antithyroid Agents; Basal Metabolism; Endocrinology; Feces; Humans; Hyperthyroidism; Hypothyroidism; Iodine Isotopes; Male; Metabolism; Perchlorates; Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Thyroid Function Tests; Thyroid Gland; Thyrotropin; Urine