technetium-tc-99m-bicisate and Brain-Diseases

Radionuclide angiography with technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) or technetium-99m ethyl cysteinate dimer (99mTc-ECD) enables the non-invasive estimation of absolute cerebral blood flow (CBF) to be determined by using spectral analysis (SA). We previously demonstrated the clinical use of SA; however, this method involves a few manual steps. The aim of this study was to evaluate the interobserver variability of CBF estimations made using SA and compare these results with those obtained by using graphical analysis (GA). In twenty patients with various brain diseases (27-74 years old), radionuclide angiography examinations were performed using 99mTc-labeled compounds (10 patients, 99mTc-HMPAO; 10 patients, 99mTc-ECD). Bilateral cerebral hemispheres were studied in all patients, and the brain perfusion index (BPI) values were estimated using SA and GA. The interobserver variability between two observers was then assessed. A good correlation between the BPI values assessed using both SA (BPI(S)) and GA (BPI(G)) was obtained. The correlation coefficient for BPI(S) (r = 0.987) was almost the same as that for BPI(G) (r = 0.982). The degree of interobserver variability was not affected by the measurement of elevated BPI values. Measurements carried out by two observers using both SA and GA exhibited a similar degree of interobserver variability. SA appears to have a satisfactory interobserver variability and may be more suitable for clinical applications.

Topics: Algorithms; Brain; Brain Diseases; Cerebrovascular Circulation; Cysteine; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Observer Variation; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic; Technetium Tc 99m Exametazime

To develop non-invasive regional cerebral blood flow (rCBF) measurements using technetium-99m ethyl cysteinate dimer (99mTc-ECD) and single-photon emission tomography (SPET), the same graphical analysis as was described in our previous reports using technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) was applied to time-activity data for the aortic arch and brain hemispheres after intravenous injection of 99mTc-ECD. Hemispherical brain perfusion indices (BPI) for 99mTc-ECD showed a highly significant correlation (n = 22, r = 0.935, P = 0.0001) with those for 99mTc-HMPAO in 11 patients who underwent both tracer studies. Using both linear regression line equations between 99mTc-ECD BPI and 99mTc-HMPAO BPI and between 99mTc-HMPAO BPI and mean cerebral blood flow (CBF) values obtained from a xenon-133 inhalation SPET method in a previous study, 99mTc-ECD BPI was converted to 133Xe CBF values (y = 2.60 chi + 9.8). Then raw SPET images of 99mTc-ECD were converted to rCBF maps using Lassen's correction algorithm. In this algorithm, the correction factor alpha was fixed to 1.5, 2.6 and infinite. In the comparison of rCBF values for 99mTc-ECD SPET with those for 99mTc-HMPAO SPET in 396 regions of interest in the aforementioned 11 patients, the fixed correction factor alpha of 2.6 gave nearly the same rCBF values for 99mTc-ECD (50.1 +/- 16.9 ml/100 g/min, mean +/- SD) as for 99mTc-HMPAO (49.9 +/- 17.3 ml/100 g/min). In conclusion, the same non-invasive method as has been used in 99mTc-HMPAO studies is applicable to a 99mTc-ECD study for the measurement of rCBF without any blood sampling.

Topics: Adult; Aged; Algorithms; Brain; Brain Diseases; Cysteine; Female; Humans; Linear Models; Male; Middle Aged; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A multicenter study was performed in seven European centers comparing 99mTc-bicisate with 133Xe as a means of evaluating bicisate as a tracer of CBF distribution in humans. The same type of single photon emission computed tomography (SPECT) instrument (Tomomatic) was used in all centers. A total of 115 cases were collected, and of these 105 were considered technically adequate, comprising 18 normal subjects, 18 senile dementia, eight epilepsy, one brain tumor, eight chronic head trauma, and 52 stroke cases. As expected, bicisate gave better spatial resolution than Xe. Agreement between the results of the two methods was noted in 98 cases, but not in the remaining 7, all belonging to the stroke group. These seven all suffered from a subacute stroke (11-23 days after onset), and the disagreement in all cases consisted of bicisate showing low count rate in the area of the infarct and Xe a normal or elevated flow (luxury perfusion) as sign of spontaneous thrombolysis with reperfusion; in fact, these seven cases comprised all the reperfusion cases in the series. The results validate bicisate as a tracer of CBF in normal humans and in chronic brain diseases. Only in a subgroup of subacute stroke cases does bicisate not follow CBF, as it fails to show reperfusion hyperemia. This suggests the usefulness of bicisate in stroke cases, particularly in the subacute phase, where other SPECT methods often present difficulties due to reflow masking the size and the severity of the lesion.

Topics: Aged; Brain Diseases; Brain Ischemia; Cerebrovascular Circulation; Cerebrovascular Disorders; Chronic Disease; Cysteine; Female; Humans; Hyperemia; Male; Organotechnetium Compounds; Reference Values; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

Topics: Adult; Brain Diseases; Cysteine; Encephalitis; Female; Hashimoto Disease; Humans; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon; Tropanes

We studied single photon emission computed tomography (SPECT) of 15 children with acute encephalopathy after more than 1 year from the onset, using technetium-99 m-L, L-ethyl cystinate dimer (99mTc-ECD) and a three-dementional stereotaxic region of interest template. Regional cerebral blood flow was evaluated and divided in three groups according to the severity of disability: absent or mild, moderate, and severe. There was no abnormality on SPECT in the patients without disability or with mild disability. Diffuse hypoperfusion was shown in the groups with moderate and severe disability. The patients with severe disability showed hypoperfusion in the pericallosal, frontal and central areas which was more pronounced than in the patients with moderate disability.

Topics: Brain; Brain Diseases; Cerebrovascular Circulation; Child; Child, Preschool; Cysteine; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon

We made a 3-dimensional, 99mTc-ECD brain perfusion single photon emission computed tomography (SPECT) database in children by a statistical analysis. We selected 52 individuals between 1 and 15 years of age whose brain SPECT and brain MRI findings were normal, and divided them into three age groups: 1-5, 6-10 and 11-15 years. By comparing databases obtained for each group, an age-dependent change of regional cerebral blood flow was investigated. The results showed that the relative blood flow increases in the frontal lobe and cerebeller hemisphere and decrease in the occipital lobe with increasing age, findings consistent with those of previous reports. This database enabled us to easily find 3-dimensional brain perfusion abnormality in individual patient by SPECT, and may help elucidate the pathophysiology of many brain disorders.

Topics: Adolescent; Age Factors; Brain; Brain Diseases; Cerebrovascular Circulation; Child; Child, Preschool; Cysteine; Female; Humans; Imaging, Three-Dimensional; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Radiopharmaceuticals; Regional Blood Flow; Tomography, Emission-Computed, Single-Photon

Bilateral symmetric striopallidodentate calcinosis, also known as Fahr's disease, is characterized by bilateral calcifications of the basal ganglia, thalami, dentate nuclei of the cerebellum, and the white matter of the cerebral hemisphere. Intracranial calcifications are easily visible as high-density areas on computed tomographic images. On magnetic resonance images, the calcifications exhibit different signal intensities. The differences in signal intensity are thought to be related to the stage of the disease, differences in calcium metabolism, and the volume of the calcium deposit. The moderate reduction of cerebral blood flow in bilateral thalami was also identified using brain SPECT.

Topics: Aged; Basal Ganglia Diseases; Brain Diseases; Calcinosis; Cerebellar Diseases; Cysteine; Dysarthria; Gait Ataxia; Humans; Male; Occipital Lobe; Organotechnetium Compounds; Paralysis; Radiography; Radiopharmaceuticals; Thalamic Diseases; Tomography, Emission-Computed, Single-Photon

Involvement of the brain is one of the most important complications of Behçet's disease, but its diagnosis is difficult because of the lack of effective imaging tools. Therefore, technetium-99m ethyl cysteinate dimer (Tc-99m ECD) single-photon emission computed tomography (SPECT) of the brain was used to detect abnormal regional cerebral blood flow in patients with neuro-Behçet's syndrome (NBS). Tc-99m ECD brain SPECT was performed to detect hypoperfusion areas of the brain in 10 NBS patients with definite neuropsychiatric symptoms or signs and normal brain magnetic resonance imaging (MRI) findings. Tc-99m ECD brain SPECT demonstrated hypoperfusion areas of the brain in all of the 10 NBS patients. The parietal lobes were the most common areas with hypoperfusion lesions. Tc-99m ECD brain SPECT is a more sensitive and useful tool than brain MRI for detecting hypoperfusion areas of the brain in NBS patients.

Topics: Adult; Behcet Syndrome; Brain Diseases; Cerebrovascular Circulation; Cysteine; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Discrepancies have been reported between the findings of Tc-99m HMPAO and Tc-99m ECD brain perfusion SPECT imaging. This study investigated the discrepancies in the accumulation of these tracers using dynamic SPECT to detect the super early phase of distribution. Thirteen patients with luxury perfusion or high flow states were studied with both dynamic and standard SPECT using Tc-99m HMPAO and Tc-99m ECD within 1-3 days. Standard SPECT showed discrepancies in 6 of 13 patients. Patients with meningioma and cerebral thrombosis had increased accumulation of Tc-99m HMPAO and decreased uptake of Tc-99m ECD. Patients with arteriovenous malformation, subarachnoid hemorrhage, and cavernous angioma had decreased accumulation of both tracers, but to different degrees. Dynamic SPECT showed increased or normal accumulation (i.e., essentially no discrepancy) in the first few minutes. However, Tc-99m HMPAO had a longer retention time than Tc-99m ECD in the ensuing 5-10 minutes. Dynamic SPECT revealed a similar accumulation pattern but different washout rates for the two tracers. Tc-99m HMPAO might be a more suitable tracer to detect high flow states or luxury perfusion because the findings on standard SPECT were more in agreement with those of dynamic SPECT using this tracer.

Topics: Adult; Aged; Brain; Brain Diseases; Brain Neoplasms; Cerebrovascular Circulation; Cerebrovascular Disorders; Cysteine; Female; Humans; Hyperemia; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to comparatively evaluate the quality of SPECT images for the mapping of rCBF using three tracers, 123I-IMP, 99mTc-HMPAO and 99mTc-ECD. We performed three SPECT studies on seven patients with various cerebral diseases under the same conditions. An effect of Lassen's correction on SPECT images obtained by HMPAO was also evaluated. The same irregular regions of interest were placed on the four transaxial SPECT images. To quantitatively evaluate the pattern of tracer uptake and image contrast, the uptake ratio, regional count/mean count of the cerebrum, and its coefficient variations (CV) were defined, respectively. The order of the value of CV was HMPAO with correction > IMP > ECD > HMPAO without correction. HMPAO with correction showed the best image contrast, but HMPAO without correction was the worst. Uptake ratios of ECD and HMPAO with correction were decreased in the brain stem and thalamus in comparison with those of IMP. Both uptake ratios of ECD and HMPAO without correction were increased in the occipital cortex. IMP provides high quality SPECT images. Images obtained by HMPAO should be modified by Lassen's correction to increase image contrast. ECD or HMPAO should not be used to evaluate patients with spinocerebellar degeneration.

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

The purpose of the study is to validate the split-dose method corrected with dose ratio of 99mTc-ECD for brain perfusion scan. A dose of 600 MBq of 99mTc-ECD was divided into two with various dose ratios from 1:1 to 1:4, and injected to eleven patients with various cerebral diseases. A lesser dose of 99mTc-ECD was injected under a control state for the first SPECT scan, and 15 min SPECT scan was performed 10 min after injection with a triple-head high resolution gamma camera. After the scan, the other dose of 99mTc-ECD was injected under the same control state and the second SPECT scan was performed as same as above. A ratio of the activity of the first scan to the net activity of the second scan corrected by dose ratio, defined as K, was measured in brain regions of each subject. Expected value of K was 1, but the value was distributed with large variations in each subject. The mean % error of the K value was 10.4 +/- 4.9%. Hence it is considered that activity changes by more than 20% from the control values should be required to detect a significant rCBF change in an activation SPECT study. Then, we proposed a new method in which the activity of both two SPECT scans was normalized by cerebellar or occipital activity and compared. The ratio obtained by the proposed method came closer to 1 with less variations and with less mean % error in comparison with those of K value obtained by the dose-correction method. Although the proposed method has a limitation in the use of an activation study loaded with Diamox, it may be useful to evaluate an alteration of rCBF in the study such as postural testing or finger-moving test.

Topics: Brain; Brain Diseases; Cerebrovascular Circulation; Cysteine; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Regional Blood Flow; Tomography, Emission-Computed, Single-Photon

A patient with neuro-Behçet's disease was studied with both Tc-99m-HMPAO and Tc-99m-ECD brain perfusion SPECT during the same time period. In Tc-99m-HMPAO SPECT, focal high uptake was observed in the left basal ganglia where MRI depicted abnormal signal intensity. Conversely, Tc-99m-ECD SPECT did not show corresponding high uptake, but demonstrated rather low uptake in contrast to the Tc-99m-HMPAO SPECT. This case suggests that Tc-99m-HMPAO and Tc-99m-ECD may show discordant distribution in inflammatory brain disease such as neuro-Behçet's disease.

Topics: Adult; Behcet Syndrome; Brain; Brain Diseases; Cysteine; Female; Humans; Magnetic Resonance Imaging; Organotechnetium Compounds; Oximes; Reproducibility of Results; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The aim of this study was to compare 99mTc-bicisate with 133Xe inhalation in regional CBF (rCBF) imaging. Five healthy volunteers and five patients were imaged with both techniques. Regional standardized values (SVs) of 99mTc-bicisate, uptake indexes (UIs), and asymmetry indexes (AIs) were compared quantitatively with, respectively, rCBF, flow indexes (FIs), and AIs. Areas with highest rCBF (sylvian and thalamic areas) appeared to be underestimated with 99mTc-bicisate, but significant correlations were found between SV and rCBF (n = 140, r = 0.468, p < 0.01) and for the 10 subjects between UI and FI and between AIs (p < 0.0001). There are therefore distinct regional differences in the cerebral distinction of 99mTc-bicisate and CBF, particularly in the thalamus and the temporal cortex. It is probable but not yet proved that an underestimation of high flow rates occurs with bicisate.

Topics: Adolescent; Adult; Aged; Brain; Brain Diseases; Cerebrovascular Circulation; Cysteine; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Reference Values; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

Topics: Adult; Aged; Brain Diseases; Cysteine; Humans; Male; Middle Aged; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon