technetium-tc-99m-bicisate and Cerebral-Infarction

Radiotracers called chemical microsphere are widely accepted as brain perfusion agents. Following the intravenous administration, these drugs are transported via the artery to the brain, cross the intact blood-brain barrier, and enter the brain tissue. Once the tracer flows into the brain, the efflux of the tracer is prevented by some trapping mechanism, resulting in prolonged retention. Because the distribution of the accumulated tracer remains approximately consistent with regional cerebral blood flow for a relatively long period, high-quality SPECT images reflecting the distribution pattern of cerebral blood flow can be acquired. However, unlike true microsphere, cerebral kinetics of the brain perfusion agents is complicated, and various causes may produce discrepancy between the distributions of the tracer and blood flow. In this review, cerebral kinetics of the brain perfusion agents used commonly is discussed. The knowledge of the mechanism of brain accumulation appears to be essential to appropriately determine the tracer of choice and interpret the obtained images.

Topics: Amphetamines; Brain; Brain Neoplasms; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Humans; Iodine Radioisotopes; Iofetamine; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime

We sought to study the prognostic value of early 99mtechnetium-ethyl-cysteinate-dimer single-photon emission CT (99mTc-ECD SPECT) for fatal ischemic brain edema in patients with middle cerebral artery (MCA) stroke compared with the prognostic value of CT and of clinical findings.. We prospectively studied 108 patients clinically, with 99mTc-ECD SPECT, and with CT within 6 hours of symptom onset (Scandinavian Stroke Scale <40 points) appropriate to MCA ischemia. The follow-up consisted of Scandinavian Stroke Scale and CT on days 1 and 7, Barthel Index, and Modified Rankin Scale after 3 months. An activity deficit of the complete MCA territory on the SPECT scans and a parenchymal hypoattenuation of the complete MCA territory on CT scans were considered as predictors for a fatal MCA infarction due to mass effect and midbrain herniation.. In 11 of 108 patients (10%), the MCA infarction was the cause of death. The sensitivity of SPECT for fatal outcome was 82% in both visual and semiquantitative analyses, while specificity was 98% and 99%, respectively. The sensitivity and specificity of baseline CT were 36% and 100%, respectively; the sensitivity and specificity of clinical findings (Scandinavian Stroke Scale, depressed level of consciousness, gaze deviation) varied from 36% to 73% and from 45% to 88%, respectively. In a multivariate logistic regression model, only SPECT findings were found to be independent predictors of malignant MCA infarction/death.. We were able to identify patients with fatal MCA infarction with high accuracy by using 99mTc-ECD SPECT within 6 hours of stroke onset. This technique offers great potential to select stroke patients for specific therapies, eg, decompressive hemicraniectomy, soon after onset of symptoms.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain Edema; Brain Ischemia; Cerebral Infarction; Cerebrovascular Disorders; Cysteine; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Prognosis; Prospective Studies; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Technetium-99m ethyl cysteinate dimer (ECD) has high initial cerebral uptake with slow clearance in nonhuman primates suggesting ideal characteristics for single photon emission computer tomography (SPECT) imaging. We evaluated the biodistribution, dosimetry and scintigraphic pattern of [99mTc]ECD in normal subjects and the accuracy of SPECT imaging in patients with chronic cerebral infarction. Sixteen normal subjects were injected with approximately 10 mCi of [99mTc]ECD. Anterior and posterior single-pass whole-body images were obtained at multiple times after injection. Blood clearance of the radiotracer was rapid, falling to 10.0 +/- 6.6% and 4.9 +/- 1.1% of the injected dose at 2 and 60 min, respectively. Brain uptake was 6.4 +/- 2.1% of the injected dose 5 min after injection. The critical organ was the urinary bladder. Technetium-99m ECD SPECT was performed with a rotating gamma camera in ten of the 16 normal subjects and 34 patients with clinical and CT evidence of chronic stroke. Thirty-three of the thirty-four patients had focal [99mTc]ECD abnormalities on SPECT (97.1%) based on visual inspection of the SPECT images. In summary, we obtained high quality SPECT images as a result of the optimal physical and biologic characteristics of the tracer. Technetium-99m ECD SPECT shows promise for the evaluation of patients with stroke.

Topics: Cerebral Infarction; Chronic Disease; Cysteine; Female; Humans; Male; Multicenter Studies as Topic; Organometallic Compounds; Organotechnetium Compounds; Radiation Dosage; Reference Values; Tissue Distribution; Tomography, Emission-Computed

Topics: Agraphia; Brain; Cerebral Infarction; Cysteine; Humans; Language Tests; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

Topics: Cerebral Infarction; Cysteine; Diffusion Magnetic Resonance Imaging; Feeding and Eating Disorders; Female; Humans; Middle Aged; Organotechnetium Compounds; Reward; Tomography, Emission-Computed, Single-Photon

Extracranial-intracranial (EC-IC) bypass surgery remains an important treatment alternative for patients with occlusive cerebrovascular disease. The aim of the present study was to use perfusion CT and CT angiography (CTA) to evaluate cerebral hemodynamics and bypass patency in patients with occlusive cerebrovascular disease before and after EC-IC bypass surgery.. Ten patients underwent perfusion CT and CTA before and after bypass surgery. Preoperative and postoperative digital subtraction angiography served as the diagnostic gold standard. An artery bypass was established from the superficial temporal artery to a cortical branch of the middle cerebral artery. Perfusion CT scanning was performed at the level of the basal ganglia. Color-coded perfusion maps of cerebral blood volume, cerebral blood flow, and time to peak were calculated.. Preoperative perfusion CT showed significant prolonged time to peak and reduced cerebral blood flow of the affected hemisphere. Postoperative neurological deterioration did not develop in any patient. Computed tomography angiography provided adequate evaluation of the anastomoses as well as the course and caliber of the bypass and confirmed bypass patency in all patients. Postoperative perfusion CT showed improved cerebral hemodynamics with a return to nearly normal perfusion parameters.. Computed tomography angiography is a noninvasive and reliable tool for evaluating patients with EC-IC bypass. Perfusion CT allows monitoring of hemodynamic changes after bypass surgery. The combination of both modalities enables noninvasive anatomical and functional analysis of superficial temporal artery-middle cerebral artery anastomoses using a single CT protocol. Hemodynamic evaluation of patients with occlusive cerebrovascular disease before and after surgery may improve the prediction of outcome and may help identify patients in whom a bypass procedure can be performed.

Topics: Anastomosis, Surgical; Angiography, Digital Subtraction; Cerebral Angiography; Cerebral Infarction; Cerebrovascular Circulation; Cerebrovascular Disorders; Cysteine; Follow-Up Studies; Humans; Monitoring, Intraoperative; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Treatment Outcome; Vascular Grafting

Hypercholesterolemia has been identified as an important risk factor for stroke. It has been reported that statins might reduce the risk for new or recurrent cardiovascular events and strokes.. This paper reports on the effects of pitavastatin on cerebral blood flow in 2 elderly patients.. Two patients, a 72-year-old right-handed Japanese man and a 77-year-old right-handed Japanese woman, both with a history of cerebral infarction, received 6-month treatment with pitavastatin 2 mg/d for complicated hypercholesterolemia. To assess regional cerebral blood flow (rCBF), single-photon emission computed tomography (SPECT) studies with technetium-99m-ethyl cysteinate dimer were carried out before and after pitavastatin administration. Tomography was evaluated using the Easy z Score Imaging System. None of the patients' other treatments, with the exception of pitavastatin initiation, were modified during the treatment period. In both patients, serum total cholesterol concentrations were improved within 3 months of initiation of pitavastatin treatment, with no marked changes in clinical symptoms. In both patients, improvement was found in rCBF on SPECT. The z score of the left parietal lobe in 1 patient was improved, from 2.20 to 1.69. That of the other patient was also improved, from 2.42 to 1.94.. In both patients, clinically significant improvement in rCBF was found after 6-month treatment with pitavastatin 2 mg/d.

Topics: Aged; Cerebral Infarction; Cerebrovascular Circulation; Cholesterol; Cysteine; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Male; Organotechnetium Compounds; Quinolines; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Cerebral infarction in infants is not uncommon, and it differs in many important ways from cerebral infarction in older children and adults. Computed tomography, ultrasound, and conventional and diffusion-weighted magnetic resonance imaging are useful for diagnosing cerebral infarction, but these imaging techniques cannot be used to measure cerebral blood flow and metabolic activity. Abnormality in those parameters seems to follow a different pattern and time course than those in older patients. In this study, the rapid changes in regional cerebral blood flow and metabolic rate of glucose were estimated by single-photon emission computed tomography and positron emission tomography during the acute and subacute phases of neonatal infarction. Subacute increases in blood flow and metabolic rate in the infarcted area of a term infant with multiple apneic episodes within 2 days after birth were observed, as well as acute increases in both in the infarcted area of a term infant with acute clonic seizures within 24 hours after birth. Follow-up studies at 4 months for the first infant and at 10 days for the second infant demonstrated that both the blood flow and metabolic rate in the infarcted region decreased. The results of this study should contribute to an understanding of the relationship between blood flow and metabolic rate changes after neonatal infarction as well as to improvement of diagnosis of neurologic impairments in neonates.

Topics: Cerebral Infarction; Cysteine; Female; Glucose; Humans; Infant, Newborn; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Mean cerebral blood flow (mCBF) in the slice including the basal ganglia (reference slice) is necessary for the quantification of regional CBF using Patlak plot and BUR methods on 99mTc-ECD cerebral perfusion SPECT. The mCBF was calculated from the mean counts of this slice. A region of interest (ROI) has been manually set on the reference slice to obtain the mean counts (manual ROI method). However, there was large variability observed in the value of rCBF in this method. We developed a 3DSRT method for improving the accuracy of the mean counts in the reference slice and evaluated the difference between the value of rCBF on manual ROI method and that on 3DSRT method in consecutive 11 patients with cerebral vascular disease. Difference in the value of mean counts of the reference slice was distributed within the 2 standard deviations (SD) with Blant-Altman analysis in 9 of 11 patients. Significant difference in the value of mean counts between two methods was observed in 2 of 11 patients. 3DSRT method is superior accuracy to the manual ROI method in the evaluation of the counts in the ROI. Lower accuracy in manual ROI method, therefore, results in the difference of the value of mean counts. 3DSRT method provides high accuracy with the various quantitative methods for the evaluation of rCBF using 99mTc-ECD.

Topics: Aged; Basal Ganglia; Brain; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Female; Humans; Imaging, Three-Dimensional; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Software; Tomography, Emission-Computed, Single-Photon

A 55-year-old right-handed male patient with atrial fibrillation was admitted to our hospital because of a sudden disturbance of consciousness and right hemiparesis. Neurological examinations revealed left conjugate deviation of the eyes, aphasia, right hemianopsia without macula sparing using a Goldmann perimeter, right hemianesthesia, and right hemiparesis. Magnetic resonance imaging showed low intensity areas (left posterior limb of internal capsule, left cerebral peduncle of middle brain, a part of left substantia nigra, left amygdala, ventral posterior lateral nucleus and ventral anterior nucleus of left thalamus, left lateral geniculate body, and left occipital lobe) in T1 weighted image, due to the infarct in the left anterior choroidal artery territory. Aphasia in this case was accompanied with non-fluent speech, good repetition, naming deficits, and perseveration. We suggest that aphasia with anterior choroidal artery syndrome cannot be classified using the conventional system, and emphasize the importance of accurate descriptions of the symptoms characteristic of aphasia with anterior choroidal artery.

Topics: Aphasia; Atrial Fibrillation; Cerebral Infarction; Choroid Plexus; Cysteine; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

The brain distribution of 9mTc-hexamethylpropyleneamine oxime (HMPAO) correlates with regional brain perfusion, whereas 99mTc-ethyl cysteinate dimer (ECD) reflects not only perfusion but also the metabolic status of brain tissue. We compared 99mTc-ECD single-photon emission CT (SPECT) with 99mTc-HMPAO SPECT early after recanalization by local intraarterial thrombolysis (LIT) in patients with acute embolic middle cerebral artery occlusion. We also assessed the predictive value of 99mTc-HMPAO and 99mTc-ECD SPECT for the development of ischemic brain damage.. 99mTc-HMPAO and consecutive 99mTc-ECD SPECT studies were performed in 15 patients within 3 hours of LIT. The two SPECT studies were obtained independently using a subtraction technique. SPECT evaluation was performed using semiquantitative region-of-interest analysis. Noninfarction, infarction, and hemorrhage were identified by follow-up CT or MR imaging.. Forty-five lesions were identified (21 noninfarctions, 19 infarctions, and five hemorrhages). Regardless of 99mTc-HMPAO SPECT findings, lesions showing isoactivity (count rate densities of 0.9 to 1.1 as compared with the contralateral side) on 99mTc-ECD SPECT were salvaged. Lesions with hypoactivity (values < 0.9) on 99mTc-ECD SPECT developed irreversible brain damage. Hemorrhage appeared in lesions with both hyperactivity (values > 1.1) on 99mTc-HMPAO SPECT and hypoactivity on 99mTc-ECD SPECT.. The brain distribution of 99mTc-ECD in a reperfused area identified by 99mTc-HMPAO SPECT early after recanalization of acute ischemic stroke is dependent on cerebral tissue viability. By combining 99mTc-ECD and 99mTc-HMPAO SPECT, performed within the first few hours of LIT, it is possible to identify patients at risk for hemorrhagic transformation reliably.

Topics: Aged; Arterial Occlusive Diseases; Brain; Cerebral Hemorrhage; Cerebral Infarction; Cysteine; Female; Fibrinolytic Agents; Humans; Injections, Intra-Arterial; Intracranial Embolism; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Brain SPECT with 99mTc-ethylcysteinate dimer (99mTc-ECD) reveals a subacute cerebral infarct as a hypoactive area, even in the presence of postischemic hyperperfusion. The brain retention of 99mTc-ECD depends on hydrophilic conversion mediated by enzymes, and impaired enzymatic trapping is hypothesized to depress the retention efficiency in the infarcted region. The aim of this study was to determine whether the metabolic rate of 99mTc-ECD is actually reduced in infarcted brain tissue.. In 50 mmol/L phosphate buffer (pH 7.4), 99mTc-ECD was incubated for 30 min with homogenates of rat brain tissue with and without triphenyltetrazolium chloride (TTC) staining. The ratio of polar products was determined by thin-layer chromatography as a function of incubation time, and metabolic rates were obtained. Permanent focal ischemia was induced by occlusion of the right middle cerebral artery (MCA) in rats. The brain was removed 24 h after MCA occlusion, and the infarcted area was defined by TTC staining. The metabolic rate of 99mTc-ECD was determined in homogenates of infarcted tissue, contralateral noninfarcted tissue, and tissue sampled from sham-operated rats. The infarct volume was measured by direct and indirect methods to assess volume expansion caused by edema, and the metabolic rate in infarcted tissue was corrected for the effect of edema.. TTC staining had no effect on the metabolic rate of 99mTc-ECD. The metabolic rates in the infarcted tissue were 0.222%/min +/- 0.054%/min and 0.285%/min +/- 0.064%/min before and after correction for edema, respectively. These rates were significantly lower than those in the contralateral noninfarcted tissue (0.426%/min +/- 0.028%/min) and the tissue sampled from the sham-operated rats (0.439%/min +/- 0.031%/min). No substantial difference in rates was observed between the contralateral tissue and the tissue from the sham-operated rats.. The results of this study showed that infarction decreases the activity of enzymes that mediate the hydrophilic conversion of 99mTc-ECD in the brain and suggest that reduced metabolic activity is related to decreased accumulation of 99mTc-ECD in hyperperfused infarcts.

Topics: Animals; Brain; Cerebral Infarction; Coloring Agents; Cysteine; Male; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Wistar; Tetrazolium Salts

To evaluate the usefulness of a combination of linearization and scatter-attenuation correction on 99mTc-bicisate (ECD)-single photon emission tomographic (SPECT) images, both cerebral blood flow (CBF)-positron emission tomographic (PET) images and ECD-SPECT images from fifteen patients with chronic cerebral infarction were acquired. We measured radioactivity counts in regions of interest (ROIs) on all sets of both images and obtained a 2D scattered graph between ECD-SPECT and CBF-PET data. To evaluate diagnostic accuracy, the sensitivity, specificity and accuracy of ECD-SPECT images were calculated by means of discriminant analysis. The same analysis was also performed on the ECD-SPECT images corrected by a combination of linearization and scatter-attenuation correction. An overall nonlinear relationship was observed between ECD-SPECT and CBF-PET. The sensitivity, specificity, and accuracy of ECD-SPECT images were 69.6%, 91.4% and 73.0%, and those of ECD images corrected by the combination of linearization and scatter-attenuation correction were 79.5%, 95.7% and 82.0% respectively. The clinically diagnostic accuracy of ECD-SPECT images corrected by the combined method apparently increased. So that the linearization with the scatter-attenuation method is useful for improving the diagnostic accuracy of ECD-SPECT images.

Topics: Aged; Brain; Cerebral Infarction; Cerebrovascular Circulation; Chronic Disease; Cysteine; Discriminant Analysis; Female; Humans; Linear Models; Male; Middle Aged; Organotechnetium Compounds; Oxygen Radioisotopes; Radiopharmaceuticals; Scattering, Radiation; Sensitivity and Specificity; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

We present a case of antiphospholipid antibody syndrome (APS) with repeated transient ischemic attacks (TIAs). Magnetic resonance imaging showed multiple cerebral infarcts and ischemic changes in the cerebral white matter. Cerebral angiographies showed no abnormalities. Technetium-99m-ethyl cysteinate dimer (Tc-99m-ECD) brain SPECT showed multiple decreased perfusion areas, which were more extensive than the lesions demonstrated on MRI. After treatment with an antiplatelet agent, the patient subsequently recovered from the TIAs. Although no interval changes were observed by MRI after therapy, follow-up Tc-99m-ECD SPECT revealed a marked improvement in brain perfusion. This is the first imaging report of remarkable post-therapy improvement in brain perfusion in APS cases.

Topics: Antiphospholipid Syndrome; Aspirin; Cerebral Infarction; Cysteine; Female; Follow-Up Studies; Humans; Middle Aged; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

In acute ischemic stroke, the infarcted core is surrounded by a zone of tissue that has decreased perfusion. Some of this tissue may be salvaged by prompt, effective treatment. Diffusion-weighted MRI is sensitive in detecting the infarcted tissue, whereas SPECT also detects the hypoperfused tissue around the infarcted core. We studied the potential of combined diffusion-weighted MRI and SPECT to predict infarct growth and clinical outcome in patients not receiving thrombolytic treatment.. Sixteen patients with acute stroke were examined consecutively with diffusion-weighted MRI and 99mTc-ethyl cysteinate dimer (99mTc-ECD) SPECT within 24 h of the onset of symptoms. Follow-up diffusion-weighted MRI was performed on the second day and after 1 wk. The volumes of infarcted and hypoperfused brain tissue were measured from diffusion-weighted MRI and SPECT, respectively. The volume difference between the hypoperfused and infarcted tissue on the first day was compared with the possible increase in infarct volume during the follow-up. Each patient's neurologic status was assessed with the National Institutes of Health Stroke Scale (NIHSS).. The volume of infarcted tissue increased from 48 +/- 54 cm3 (mean +/- SD) on the first day to 88 +/- 93 cm3 on the second day (P = 0.001) and to 110 +/- 121 cm3 at 1 wk (P = 0.001). The volume of hypoperfused tissue on the first day was significantly greater than the infarct volume (102 +/- 135 cm3; P = 0.001). The volume difference between the hypoperfused and infarcted tissue on the first day correlated significantly with the infarct growth between the first day and 1 wk (r = 0.71; P < 0.01). Between the first day and 1 wk, the increase of the infarct volume correlated significantly with the change in the NIHSS (r = 0.54; P < 0.05).. A large hypoperfusion zone around the infarct core in the acute phase of ischemic stroke predicts the infarct growth during the first week, and this correlates significantly with the change in the neurologic status of the patient. Combined diffusion-weighted MRI and SPECT performed within 24 h after the onset of symptoms can be useful in the evaluation of acute stroke to predict infarct growth.

Topics: Acute Disease; Aged; Aged, 80 and over; Brain; Brain Ischemia; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Disease Progression; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Cerebral infarct due to embolic stroke without recanalization was examined by cerebral blood flow (CBF) SPECT in the early acute stage, and the possibility of predicting the size it will reach in the later stages was evaluated. Twenty patients (67 +/- 13 years) were examined by CBF SPECT with 99mTc-ECD 4.5 +/- 3.1 hours after the onset of cardiogenic cerebral embolism. The ratio of the anteroposterior length of the cerebral hemisphere to that of the severe ischemic region, which was defined as an area of clear-cut severe reduction in CBF as observed by SPECT, was calculated. One week after the onset, the cerebral infarct was measured in the same manner by CT, and the relationship between the two measurements was evaluated. The CBF in the region of severe ischemia and the surrounding region was determined by the Patlak plot method, and the affected/non-affected (A/NA) ratio was calculated. In severe ischemic regions the CBF ranged from 1.7 ml/100 g/min to 20 ml/100 g/min (mean, 11 +/- 5 ml/100 g/min), whereas the A/NA ratio ranged from 4% to 45% (mean, 26 +/- 11%). On the other hand, the CBF in the surrounding regions ranged from 20 ml/100 g/min to 52 ml/100 g/min (mean, 34 +/- 8 ml/100 g/min) whereas the A/NA ratio ranged from 52% to 104% (mean, 77 +/- 11%). The coefficient of correlation between the infarct size predicted by SPECT and that measured by CT was r = 0.986, and the correlation equation was Y = 1.047X - 2.969. CBF SPECT performed in the early acute stage can be used to predict the size of cerebral infarct.

Topics: Aged; Brain; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Functional Laterality; Humans; Image Processing, Computer-Assisted; Intracranial Embolism; Male; Organotechnetium Compounds; Radiopharmaceuticals; Regional Blood Flow; Regression Analysis; Time Factors; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

We report a right-handed 67-year-old woman with an infarction in the left posterior cerebral artery territory presenting amnesic syndrome, right homonymous hemianopsia, pure alexia, color anomia, and defective route finding. The patient often walked in wrong directions out of her hospital room as well as in her home. She was able to recognize her own house and nearby streets by looking at them. Prosopagnosia and constructional impairment was not observed. Wechsler memory scale revised (WMS-R) revealed that she had marked disturbance in both visual and verbal recent memory. Brain MRI revealed an infarction involving the left medial inferior temporal and left medial occipital lobe, the left splenium of corpus callosum, and the left retrosplenial region. SPECT indicated a defect in the left medial occipital lobe and hypoperfusion in the left medial temporal lobe. Cerebral angiography demonstrated stenosis of the left medial occipital artery and occlusion of the left dorsal corpus callosal branches and the left calcarine artery. We conclude that left hippocampus, left parahippocampal gyrus and the left retrosplenial region may cause memory disturbance in our case. The lesion in the left retrosplenial region may have contributed to the occurrence of defective route finding. The relation between defective route finding and the retrosplenial amnesia is discussed.

Topics: Aged; Amnesia; Brain; Cerebral Angiography; Cerebral Infarction; Cysteine; Female; Humans; Magnetic Resonance Imaging; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

Two patients with subacute cerebral infarction underwent benzodiazepine receptor imaging using I-123-iomazenil and cerebral perfusion imaging with Tc-99m HMPAO and Tc-99m ECD. Iomazenil early images resembled HMPAO images, which demonstrated increased uptake in a part of the infarcted site. Iomazenil delayed images and ECD images showed reduced accumulation in the same area. Crossed cerebellar diaschisis was observed in HMPAO, ECD, and iomazenil early images, but it was not remarkable in iomazenil delayed images. These cases suggest that sequential iomazenil images visualized increased uptake with relatively impaired viability in the infarcted site and hypoperfusion with preserved viability in the contralateral cerebellar hemisphere, which could not be recognized without using both HMPAO and ECD in the subacute phase of cerebral infarction.

Topics: Adult; Brain; Cerebellum; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Female; Flumazenil; Humans; Iodine Radioisotopes; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Receptors, GABA-A; Technetium Tc 99m Exametazime; Temporal Lobe; Tissue Survival; Tomography, Emission-Computed, Single-Photon

In the present study we developed a method for quantifying regional cerebral blood flow (rCBF) using 99mTc-ECD SPECT based on a 3-compartment model. The dynamic SPECT scanning and sequential sampling of arterial blood were performed on 12 subjects with cerebrovascular diseases and etc. We defined brain fractionation index (BFI) as a parameter of rCBF, which was obtained from a single SPECT data and arterial input. The relationship between the values of BFI and rCBF obtained by the 133Xe inhalation method was analyzed by approximation with exponential function. In this method, rCBF was calculated from the values of BFI using the inverse function of the exponential function as a regression curve. The method was applied seven other patients with cerebrovascular diseases and the values of rCBF were compared with those obtained by the 133Xe inhalation method. We observed a good correlation (r = 0.854), and the inclination was approximately 1. This method can be applied to not only large field SPECT cameras but also conventional SPECT cameras.

Topics: Adult; Aged; Brain; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Female; Humans; Male; Middle Aged; Models, Biological; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

Topics: Aged; AIDS-Related Opportunistic Infections; Brain Ischemia; Brain Neoplasms; Cerebellar Neoplasms; Cerebral Infarction; Cysteine; Diagnosis, Differential; Fatal Outcome; Humans; Lymphoma, AIDS-Related; Male; Necrosis; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Mean cerebral blood flow (mCBF) was measured by SPECT using the 99mTc-ECD-Patlak-Plot method in a selected group of 61 normal non-hospitalized subjects aged 51 to 91 years. The mCBF values showed 48.4 +/- 4.7 ml/100 g/min in aged 50-59 years group, 49.9 +/- 5.9 ml/100 g/min in aged 60-69 years group, 46.4 +/- 6.5 ml/100 g/min in aged 70-79 group, 38.0 +/- 3.7 ml/100 g/min in aged 80-89 years group, 38.9 ml/100 g/min in aged 90-99 years group. There was a statistically significant reduction of mCBF with advancing age (R = -0.41; p = 0.001). Women have significantly higher mCBF values than men up to aged 70 years group. In this study, there was no significant laterality in the mCBF between right and left hemispheres in all decade groups. The history of hypertension, alcohol consumption, and cigarette smoking failed to show significant difference in the mCBF values. The present study shows that normal aging is associated with mCBF reduction.

Topics: Aged; Aged, 80 and over; Aging; Brain; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Dementia; Female; Humans; Male; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Topics: Anomia; Brain; Cerebral Infarction; Cysteine; Humans; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Three patients with subacute ischemic cerebral infarction examined by SPECT with 99mTc-ECD and PET within the same day showed signs of luxury perfusion in the subacute phase, which is between 9 to 20 days after the onset. A 99mTc-HMPAO SPECT study was also performed within 2 days of the ECD-SPECT study. ECD-SPECT images of three patients displayed a focal decreased uptake in the infarcted lesions, while in infarcted foci, there was almost equivalent or increased CBF compared to normal and unaffected areas, decreased CMRO2, and high HMPAO uptake. The ECD-SPECT results were similar to those of CMRO2 rather than CBF, though the HMPAO-SPECT image was similar to that of CBF. In one patient, HMPAO images revealed hyperfixation of the tracer. In the chronic phase and in the acute phase before 5 days after the onset, there were no discrepancies among the ECD-SPECT, CBF, HMPAO-SPECT, and CMRO2 images. These observations indicated that 99mTc-ECD is a good indicator of damaged brain tissues in subacute ischemic infarction. They also suggested that 99mTc-ECD is a potential agent with which to evaluate cerebral tissue viability in some pathological states of cerebrovascular disease. The characteristics may be suitable for confirming the effects of thrombolytic therapy in acute ischemia, because these conditions often show signs of luxury perfusion when the therapy is successful.

Topics: Aged; Brain; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Oxygen Consumption; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Acute Disease; Adult; Blood Flow Velocity; Brain Edema; Cerebral Arteries; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Humans; Ischemic Attack, Transient; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon

Topics: Cerebral Infarction; Cysteine; Humans; Organotechnetium Compounds; Oximes; Radioactive Tracers; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

To assess the clinical role of 99mTc-ethyl cysteinate dimer (ECD) as a cerebral perfusion tracer, 10 patients with unilateral cerebral infarction were studied.. ECD SPECT images were compared with IMP and/or HMPAO SPECT in nine patients, seven in chronic phases and two in subacute phases. Five of these patients and one additional patient with chronic infarction received PET imaging in order to compare ECD distribution with quantitative regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO2) images.. In patients with chronic cerebral infarction, regression analysis showed excellent correlation between ECD and IMP in the uptake ratio of lesions-to-nonaffected cortices (r = 0.91). In two cases of subacute infarction, decreased uptake of ECD was observed in the area of "luxury perfusion," which showed elevated or preserved rCBF with diminished rCMRO2. On visual analysis, ECD image contrast was less prominent compared to that of IMP, but contrast was better than that of HMPAO.. ECD uptake showed a curvilinear relationship against rCBF, suggesting flow-limited uptake in a high flow range. ECD is a clinically useful cerebral perfusion tracer with distinct characteristics when compared with other available agents.

Topics: Adult; Amphetamines; Brain; Cerebral Infarction; Cerebrovascular Circulation; Contrast Media; Cysteine; Female; Humans; Iodine Radioisotopes; Iofetamine; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

The usefulness of a new cerebral perfusion imaging radiopharmaceutical, 99mTc-ethyl cysteinate dimer (ECD), was clinically evaluated. The subjects of this study were 14 patients with neurological disorders including 10 patients with cerebral infarction and 4 patients with other diseases. A total of 15 examinations was performed. 99mTc-HM-PAO or 123I-IMP SPECTs were performed simultaneously, and the findings from those examinations were compared with 99mTc-ECD. As to the count ratio of lesions to normal area (L/N), the L/N ratio in severe ischemic patients was lower in 99mTc-ECD than in 99mTc-HM-PAO or 123I-IMP. In mild ischemic patients, on the other hand, the L/N ratio was the lowest in 123I-IMP. When the relationship between rCBFs obtained from 123I-IMP and the values of L/N in 99mTc-ECD or 99mTc-HM-PAO was compared, the values of L/N in 99mTc-ECD or 99mTc-HM-PAO were found to have decreased linearity with increasing rCBF. In a patient showing luxury perfusion, the accumulation pattern of 99mTc-ECD was different from that of the other two radiopharmaceuticals, and focal defect was revealed in 99mTc-ECD SPECT. On the dynamic SPECT of 99mTc-ECD in a patient with meningioma, the tumor showed a change from high to low perfusion with the passage of time. This finding indicated that care should be taken in the evaluation of accumulation of 99mTc-ECD. Therefore, 99mTc-ECD was found to be useful as a cerebral perfusion agent. In addition, as accumulation of 99mTc-ECD might somehow reflect metabolism in some cases, further careful investigation of many cases should be carried out.

Topics: Adult; Aged; Amphetamines; Cerebral Infarction; Cysteine; Female; Humans; Iodine Radioisotopes; Iofetamine; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon