sodium-pertechnetate-tc-99m and Congenital-Hypothyroidism

At the molecular level, the uptake of radioiodine and pertechnetate is proportional to the expression of the thyroidal sodium/iodine symporter (NIS). Qualitative and quantitative scintigraphic evaluation of the thyroid is performed with a gamma camera fitted with an on-line computer system and enables determination of the iodine uptake or the technetium uptake (TCTU) as an iodine clearance equivalent. Despite new molecular genetic insights into congenital hypothyroidism, the iodine-123 or pertechnetate scan remains the most accurate test for the detection of ectopic thyroid tissue. Following the identification of specific mutations of the genes coding for the NIS, thyroid peroxidase and pendrin, the discharge test has lost its role in establishing the diagnosis of inherited dyshormonogenesis, but it is still of value in the assessment of defect severity. In PDS mutations the test can be used to establish the diagnosis of syndromic disease. Quantitative pertechnetate scintigraphy is the most sensitive and specific technique for the diagnosis and quantification of thyroid autonomy. The method has proved to be valuable in risk stratification of spontaneous or iodine-induced hyperthyroidism, in the estimation of the target volume prior to radioiodine therapy and in the evaluation of therapeutic success after definitive treatment. In iodine deficiency areas the thyroid scan remains indispensable for the functional characterisation of a thyroid nodule and is still a first-line diagnostic procedure in cases of suspected thyroid malignancy. This is especially of importance in patients with Graves' disease, among whom a relatively high prevalence of cancer has been found in cold thyroid nodules. While determination of the TCTU is without any value in the differentiation between autoimmune thyroiditis and Graves' disease in most cases, it is of substantial importance in the differentiation between hyperthyroid autoimmune thyroiditis and Graves' disease.

Topics: Adult; Child; Congenital Hypothyroidism; Gamma Cameras; Humans; Iodine Radioisotopes; Ion Channels; Ion Transport; Perchlorates; Potassium Compounds; Prognosis; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Symporters; Thyroid Diseases; Thyroid Function Tests; Thyroid Gland; Thyroid Neoplasms; Thyroid Nodule; Thyroiditis, Autoimmune; Ultrasonography

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

A 4-day-old female neonate with raised cord blood thyroid-stimulating hormone (127 μIU/mL) underwent Tc thyroid scan to rule out thyroid dysgenesis. The images revealed midline focus of lingual thyroid as the only functioning thyroid tissue. In addition, bilateral focal and symmetrical breast uptake was seen without clinically palpable breast nodule on either side. Transplacental transfer of maternal hormones leading to stimulation of neonatal breasts explains this unusual scan finding. One should be aware of this rare pattern of focal breast uptake in Tc-pertechnetate scan in neonates with congenital hypothyroidism to avoid scan misinterpretation.

Topics: Biological Transport; Breast; Congenital Hypothyroidism; Female; Humans; Infant, Newborn; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

A 9-day-old female infant with congenital hypothyroidism presented for thyroid scintigraphy. Multiple attempts including the "intravenous team" failed to establish peripheral access for administration of 99mTc-pertechnetate. We administered 99mTc-pertechnetate subcutaneously into the upper arm. Rapid absorption (85% of the dose in 20 minutes) was documented on dynamic images with physiological uptake, allowing diagnostic thyroid scintigraphy at 35 minutes that revealed ectopic sublingual thyroid. Subcutaneous injection allowed us to avoid traumatic and risky central vascular access procedure. When peripheral intravenous access cannot be obtained, 99mTc-pertechnetate can be administered subcutaneously for diagnostic thyroid scintigraphy, which is particularly useful in neonates.

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

The purpose of this study was to retrospectively evaluate the use of sonography as the primary imaging modality for congenital hypothyroidism (CH).. From our regional registry, we reviewed the cases of patients for whom either sonography or (99m)Tc-pertechnetate scanning was performed for CH between 2003 and 2010. Ultrasound studies were reviewed for presence, size, echotexture, vascularity, and location of the thyroid gland. Technetium-99m-pertechnetate scans were evaluated for the presence and location of the thyroid gland. The ultrasound studies were compared with the (99m)Tc-pertechnetate scans. We assessed the use of ultrasound as the primary imaging modality for the evaluation of CH.. We identified the cases of 124 patients (89 girls, 35 boys). Ultrasound studies were available for 121 patients, and (99m)Tc-pertechnetate studies for 62 patients. Three patients were examined only by (99m)Tc-pertechnetate scanning. The final imaging results were normal location with normal size or diffuse enlargement of the thyroid gland (n = 47), sublingual thyroid gland (n = 49), agenesis (n = 18), hypoplasia (n = 8), and hemiagenesis (n = 2). Compared with (99m)Tc-pertechnetate scanning, ultrasound had high (100%) specificity and low (44%) sensitivity for detection of sublingual thyroid gland.. We suggest using ultrasound as the primary imaging modality for guiding the treatment of children with CH, potentially decreasing radiation exposure and cost.

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

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

Thyroid imaging is helpful in confirming the diagnosis of congenital hypothyroidism and in establishing the aetiology. Although isotope scanning is the standard method of imaging, ultrasound assessment may be complementary.. To determine the strengths and weaknesses of thyroid ultrasound and isotope scanning in neonates with thyroid stimulating hormone (TSH) elevation.. Babies from the West of Scotland with raised capillary TSH (>15 mU/l) on neonatal screening between January 1999 and 2004 were recruited. Thyroid dimensions were measured using ultrasonography, and volumes were calculated. Isotope scanning was carried out with a pinhole collimator after an intravenous injection of 99m-technetium pertechnetate.. 40 infants (29 female) underwent scanning at a median of 17 days (range 12 days to 15 months). The final diagnosis was athyreosis (n = 11), ectopia (n = 12), hypoplasia (n = 8; 3 cases of hemi-agenesis), dyshormonogenesis (n = 5), transient hypothyroidism (n = 2), transient hyperthyrotropinaemia (n = 1) and uncertain status with gland in situ (n = 1). 6 infants had discordant scans with no isotope uptake but visualisation of thyroid tissue on ultrasound. This was attributed to TSH suppression from thyroxine (n = 3); maternal blocking antibodies (n = 1); cystic degeneration of the thyroid (n = 1); and possible TSH receptor defect (n = 1).. Isotope scanning was superior to ultrasound in the detection of ectopic tissue. However, ultrasound detected tissue that was not visualised on isotope scanning, and showed abnormalities of thyroid volume and morphology. We would therefore advocate dual scanning in newborns with TSH elevation as each modality provides different information.

Topics: Congenital Hypothyroidism; Female; Humans; Infant; Infant, Newborn; Male; Neonatal Screening; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Thyrotropin; Thyroxine; Ultrasonography

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

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

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

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: 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: Choristoma; Congenital Hypothyroidism; Female; Humans; Infant, Newborn; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Tongue Diseases

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

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

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

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

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: Congenital Hypothyroidism; Humans; Infant, Newborn; Infant, Newborn, Diseases; Radionuclide Imaging; Salivary Glands; Sodium Pertechnetate Tc 99m; Technetium