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The aim of this study was to determine the time-activity curve in the cardiac and hepatic region by 99mTc-GSA dynamic SPECT which is clinically used in liver scintigraphy and evaluate the temporal changes in the consistency and errors at the absolute scale using the regression equation of changes in the blood concentration of 99mTc-GSA.In 11 patients who underwent 99mTc-GSA dynamic SPECT over the 30 min period after IV injection, the percentages of activity in the collected blood and in the blood pool estimated by dynamic SPECT were determined as the plasma clearance by blood collection and as the blood clearance by cardiac pooling. Extrahepatic uptake, expressesd as 100--(% uptake in the liver by dynamic SPECT (%)) was calculated as the blood clearance by the liver. The regression equation (Y = Y0 + Ae(-alphat)) was determined from the changes in the counts, expressed as a percent. Percent errors and the differences in the Y-intercept (Y0), coefficient (A) and slope (alpha) on the regression curve were compared.Blood pool clearance gradually exceeded the measured plasma clearance. The clearance by the liver started from a very low initial value and gradually became equal to that of plasma clearance over the first 15 minutes and exceeded it over the second 15 minutes. The Y-intercept was significantly higher in the blood pool clearance than that in the measured plasma clearance (p0.001), and the coefficient was significantly lower in the former than the latter (p0.001). The coefficient and slope were significantly lower in the hepatic clearance than the plasma clearance (p0.001, p0.005).The time-activity curve of the blood pool showed a tendency towards overestimation in the second half of the examination, probably due to scatter effect from the liver. The time-activity curve of liver uptake showed a tendency towards overestimation in the first half of the examination, probably due to the high concentration in the hepatic blood pool, and underestimation in the second half.

1. 1.A 78-year-old female with DDST and pain disorder was treated by clomipramine 20–100 mg/day. The hypochondriacal delusion was completely resolved, while the pains were partially resolved. 2. 2.The SPECT using Xe-133 taken at the early stage of clomipramine treatment, when she still had hypochondriacal delusions, showed markedly reduced rCBF in the temporal and parietal lobes, with predominance on the left hemisphere. Meanwhile, the SPECT taken after resolution of the hypochondriacal delusions showed a marked improvement in the reduced rCBF. 3. 3.This report suggests that DDST has some association with reduced rCBF in the temporal and parietal lobes.

This survey was performed in order to investigate the incidence of adverse reactions to radiopharmaceuticals in FY2006 in Japan. It was based on responses to questionnaires sent to nuclear medicine institutions. The reply was obtained from 975 institutions among 1263 to which the questionnaire had been sent. Thirty-two cases of adverse reactions were reported. A total of 1,189,127 radiopharmaceutical administrations was reported. The incidence of adverse reactions per 100,000 cases was 2.7. Three cases of defect products were reported, and the incidence of defect products per 100,000 cases was 0.3.

To determine the relationship between functional recovery and improvement in perfusion after coronary artery bypass graft surgery (CABG), 49 patients were studied. Radionuclide angiography was performed before, 1 month after, and 6 to 12 months after CABG to evaluate regional wall motion. Exercise thallium-201 myocardial perfusion imaging was done before and 1 month after CABG to assess regional perfusion. Preoperative asynergy was observed in 108 segments, and 74 of them showed an improvement in wall motion 1 month after CABG (segment A). Sixty-six of these segments (89%) were associated with an improvement in perfusion. Eight segments that had not improved 1 month after CABG demonstrated a delayed recovery of wall motion 6 to 12 months after CABG (segment B). However, seven of eight segments (88%) already showed an improvement in perfusion 1 month after CABG. A total of 82 segments exhibited functional recovery after CABG and were considered hibernating segments. In the preoperative study segment B more frequently had areas of akinesis or dyskinesis than segment A (75% vs 34%, p less than 0.05). The mean percent thallium-201 uptake in segment B was lower than that in segment A (74% +/- 9% vs 83% +/- 8%, p less than 0.05). Functional recovery of hibernating myocardium usually coincided with an improvement in perfusion. However, delayed functional recovery after reperfusion was observed in some instances. Severe asynergy and severe thallium-201 defects were more frequently observed in these segments with delayed recovery. Hibernating myocardium might remain stunned during those recovery periods.

This survey was performed in order to investigate the incidence of adverse reactions to radiopharmaceuticals in FY2005 in Japan. It was based on responses to questionnaires sent to nuclear medicine institutions. The reply was obtained from 1,007 institutions among 1,243 to which the questionnaire had been sent. Nineteen cases of adverse reactions were reported. A total of 1,264,098 radiopharmaceutical administrations was reported. The incidence of adverse reactions per 100,000 cases was 1.5. Three cases of defect products were reported, and the incidence of defect products per 100,000 cases was 0.2.

Regional cerebral blood flow (rCBF) was determined by the 133Xe inhalation technique (Headtome II: ring detection SPECT) in 53 DSM-III schizophrenic patients. The rCBF values were corrected by using end-tidal carbon dioxide concentration values (PECO2). After rCBF measurement, neuropsychological tests--Word Fluency Test, Maze Test and Wisconsin Card Sorting Test--were performed. There were significant correlations between frontal rCBF and scores on each neuropsychological test. In particular, a moderate correlations between the frontal rCBF and the performance on the Wisconsin Card Sorting Test was noted. It seems likely that decrease of rCBF in prefrontal regions at rest reflects a disturbance of frontal lobe function in schizophrenic patients.

According to the three hypotheses on the regional brain dysfunction in schizophrenia that have received some support in studies of cerebral blood flow (CBF) and cerebral metabolic rate, we calculated eight CBF measurement indices in 59 schizophrenic patients; frontality, laterality, cortical to subcortical gradients and superior to inferior difference. Four factors were selected from these eight indices, treated by principal component factor analysis (factor 1: cortical to subcortical gradient; factor 2: inferior frontality; factor 3: superior frontality; factor 4: laterality). We investigated their correlations with clinical and demographic characteristics. Factor 1 correlated with duration of illness. Factor 2 related most highly to numbers of perseverative errors on the Wisconsin Card Sorting Test and moderately to anhedonia. Factor 4 related to attentional impairment score of the Scale for the Assessment of Negative Symptoms. The schizophrenia specific symptom score calculated from the Brief Psychiatric Rating Scale did not relate to any of these factors. It seemed that there were various dimensions of neural deficits in schizophrenia, corresponding to various aspects of symptomatology or neuropsychological functions.

This survey was performed in order to investigate the incidence of adverse reactions to radiopharmaceuticals and defect products in FY2004 in Japan. It was based on responses to questionnaires sent to nuclear medicine institutions. The reply was obtained from 968 institutions among 1,220 to which the questionnaire had been sent. Sixteen cases of adverse reactions were reported. A total of 1,277,906 radiopharmaceutical administrations was reported. The incidence of adverse reactions per 100,000 cases was 1.3. Eight cases of defect products were reported, and the incidence of defect products per 100,000 cases was 0.6.

To analyze the retention process of technetium-99m ethyl cysteinate dimer (99mTc-ECD) in normal and ischemic lesions, we developed a super rapid dynamic SPECT system based on the CERASPECT (DSI, Inc., Waltham, MA, USA). The system made it possible to take a SPECT series every 2 seconds. Each SPECT series contains a maximum of 16 slices (6.6 mm slice interval) in a matrix size of 32 x 32. The sensitivity of this system is 175 kcps/MBq/ml/cm slice thickness, and resolution is 12 mm FWHM at the center of a 20 cm(phi) water phantom. Using the super rapid SPECT system, the kinetic behavior of the 99mTc-ECD during retention in normal and ischemic lesions was analyzed. Twenty patients with ischemic lesions that were clearly demonstrated by 133Xe-rCBF (regional cerebral blood flow) SPECT but unclear on static 99mTc-ECD SPECT were examined. For the dynamic SPECT, 700 MBq of 99mTc-ECD was injected intravenously, and dynamic SPECT data were acquired every 2 seconds during a 90-second period. The serial dynamic SPECT and time-activity curves at some lesions with reduced rCBF and at the contralateral normal brain were analyzed. These dynamic SPECT data were compared with conventional static 99mTc-ECD SPECT and quantitative 133Xe-rCBF SPECT. All of mildly or moderately reduced rCBF lesions on the 133Xe-rCBF SPECT were recognized as low activity regions only at the early phase (during about 2-20 sec or less), with the lesions then gradually vanishing. These lesions were not recognized on the conventional static SPECT taken after the dynamic study. The time-activity curve at the reduced rCBF lesion was lower than that of contralateral normal brain at the early phase, and overtook the activity in the normal region with a gradual increase. The early phase images of 99mTc-ECD SPECT within 20 seconds by the super rapid dynamic SPECT were very useful to the same extent as the 133Xe-rCBF SPECT for detecting mild or moderate ischemic lesions. This study suggests that esterase activity, participating in the ECD retention mechanism, may be tolerable to mild or moderate ischemia. This tolerance may be the main cause of the nonlinear relationship between ECD accumulation and cerebral blood flow.

A patient with bilateral diminished visual acuity and blurred vision was given the diagnosis of psychogenic visual disturbance after extensive psychiatric and ophthalmological examinations. Single photon emission computed tomography with Tc-99m-ethylcysteinate dimer demonstrated remarkably reduced regional cerebral blood flow (rCBF) in the bilateral occipital lobes. More specifically, rCBF was reduced in the visual association areas, but not in the primary visual areas. These findings suggest that functional suppression of the visual association area is associated with the development of psychogenic visual disturbance.

Relative regional cerebral blood flow was measured with single photon emission computed tomography (SPECT) using 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) in 16 patients with major depression while they were in the depressed state as well as in remission. All patients were closely matched with regard to medication status. In the depressed state, significant reductions in tracer uptake were found in the left superior frontal, bilateral parietal and right lateral temporal cortex. During remission, significant increases in uptake were found in the left superior frontal, right parietal and right lateral temporal cortex. There were no significant differences in tracer uptake between patients in remission and controls. These findings suggest that the regional decreases in tracer uptake observed in the depressed state might be a state-related abnormality.

Recently, two methods have been proposed for regional cerebral blood flow (rCBF) quantitation using [123I]iodoamphetamine (IMP) and single-photon emission computed tomography (SPECT). The table look-up (TLU) method has been shown to provide both rCBF and volume of distribution, Vd, images from two SPECT scans, while a single-scan autoradiographic (ARG) technique provided rCBF using a fixed and assumed Vd. In both methods, a single blood sample was referred to calibrate the previously determined standard input function The present multicenter project was designed to evaluate the accuracy of both methods for use as clinical investigative tools. Ten independent institutions performed [123I]IMP-SPECT studies according to both methods in 76 subjects (10 normal volunteers, 32 patients with cerebrovascular disease, and 34 patients with other diseases). Calculated rCBF values were compared with those obtained by the following reference methods available in the participating institutions; [15O] H2O positron emission tomography (PET) (five institutions), [133Xe]SPECT (four institutions), and the [123I]IMP microsphere method (three institutions). Both ARG and TLU methods provided rCBF values that were significantly correlated with those measured by the [15O] H2O PET technique ( p < 0.001 for all subjects; overall regression equation, y = 15.14 + 0.54×) and those measured by the [123I]IMP-microsphere method ( p < 0.001 for all subjects; y = 2.0 + 0.80×). Significant correlation ( p < 0.05) was observed in 18 of 24 subjects studied with the [133Xe] SPECT reference technique (overall regression equation, y = 15.0 + 0.55×). Mean cortical gray matter rCBF in a group of normal subject was 43.9 ± 3.3 and 43.4 ± 2.0 ml/min/100 g for the ARG and TLU methods, respectively. Regional Vd of [123I]IMP estimated by the TLU method was 45 ml/ml ± 20% in the normal cortical region. Close agreement between ARG and TLU rCBF values was observed (y = −3.21 + 1.07×, r = 0.97), confirming the validity of assuming a fixed Vd in the ARG method. Results of this study demonstrate that both the ARG and TLU methods accurately and reliably estimate rCBF in a variety of clinical settings.

Thallium-201 (Tl-201) distribution during adenosine infusion was assessed quantitatively and compared with that of exercise imaging. Adenosine and exercise Tl-201 single-photon emission computed tomography (SPECT) were performed in 40 patients with suspected coronary artery disease. In the whole-body images (n = 5) and the unprocessed anterior projection images acquired as part of the initial imaging (n = 35), Tl-201 counts in the myocardium were normalized for the injected dose. Total heart counts were higher during adenosine infusion than during exercise (190 +/- 43 counts/MBq vs 145 +/- 31 counts/MBq, p0.01). A heart-to-lung count ratio between adenosine infusion and exercise was not different. A heart-to-liver count ratio was lower during adenosine infusion than during exercise (1.3 +/- 0.3 vs 2.3 +/- 0.5, p0.01). Regional Tl-201 uptakes at the inferior wall of the left ventricle during adenosine infusion were closely correlated with those uptakes during exercise (r = 0.94, p0.01, slope = 0.96). The sensitivity, specificity, and accuracy of adenosine Tl-201 SPECT for the detection of right coronary artery stenosis were comparable with those of exercise imaging. These results indicated that higher Tl-201 uptake in the liver during adenosine than during exercise did not interfere with the interpretation of myocardial images. Tl-201 counts in the myocardium that were larger during adenosine infusion than during exercise reflected a larger increase in coronary blood flow and thus resulted in better image quality.

Advanced coronary artery disease, defined as left main or three-vessel coronary disease, was identifiable noninvasively by means of adenosine Tl-201 single photon emission tomography. Among 75 consecutive patients with angiographically documented coronary artery disease, there were 11 patients with the presence (group 1) and 64 patients with the absence (group 2) of advanced coronary artery disease. The lung-to-heart ratio (L/H ratio) of Tl-201 uptake was calculated as the fraction of average Tl-201 counts per pixel in the lung divided by those in the myocardium. The left ventricular dilation ratio (LVDR) was determined as a ratio of left ventricular cavity size in the early image to that in the delayed image. The patients in group 1 had more defects (2.3 +/- 0.6 seg. vs. 0.9 +/- 0.7 seg., p0.001), a higher L/H ratio (35 +/- 4% vs. 28 +/- 5%, p0.001) and a higher LVDR (1.13 +/- 0.04 vs. 1.06 +/- 0.04, p0.001) than those in group 2. The diagnostic accuracy of the identification of advanced coronary artery disease was 89% by perfusion defects, 68% by L/H ratio and 81% by LVDR. Stepwise discriminant analysis revealed that LVDR (F = 36.2, p0.0001) and perfusion defects (F = 8.9, p0.004) were the significant and independent discriminators of advanced coronary disease. Identification of patients with left main or three-vessel coronary disease was enhanced by additional analysis of cavity dilation of the left ventricle and increased Tl-201 activity in the lung.

We compared radiographic findings and the retention of N-isopropyl- p[123I]-iodoamphetamine (123I-IMP) in 23 patients with pulmonary fibrosis. During the 30 minutes following a rapid injection of 55.5 MBq of 123I-IMP into the antecubital vein, the image of regional activity was stored. After this, 185 MBq of 99mTc-MAA was injected and its image was stored to determine the region of interest. The half time (T1/2) of 123I-IMP release from the lung was calculated in each pixel between 10 and 25 minutes after the injection. Chest roentgenograms were taken, and the lung field was divided into 6 portions (right upper, middle and lower, and left upper, middle and lower). A quantitative score was assigned to the radiographic finding (X-ray score). The T1/2 values in the above patients were longer than the T1/2 values in normal subjects. Prolonged T1/2 values were observed in the lung fields which had high X-ray scores. The X-ray scores and the T1/2 values in corresponding areas had a positive relation.

To investigate the significance and mechanism of dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging, we performed both dipyridamole thallium-201 imaging and dipyridamole radionuclide anglography on 83 patients with known angiograms. The dipyridamole/delayed ratio of the left ventricular dimension from the thallium-201 image was defined as the left ventricular dilatation ratio (LVDR). An LVDR greater than the mean + two standard deviations in patients without coronary artery disease was defined as abnormal. Twenty-two of 83 patients showed an abnormal LVDR, and 18 of the 22 patients (82%) had triple-vessel disease. By defect and washout analysis, the sensitivity and specificity for correctly identifying the patients as having triple-vessel disease was 72% and 76%, respectively, whereas LVDR had a sensitivity of 72% and a specificity of 93%. When LVDR was used in combination with the defect and washout criteria, sensitivity increased to 84% without a loss of specificity. In those 22 patients with abnormal LVDRs, end-diastolic volume measured by radionuclide angiography did not change after dipyridamole infusion. Dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging reflected relative subendocardial hypoperfusion induced by dipyridamole rather than actual chamber enlargement. The LVDR was moderately sensitive and highly specific for triple-vessel disease and provided complementary information to dipyridamole thallium-201 imaging.

This study was done to evaluate the quantification of thallium-201 myocardial perfusion imaging (MPI) for the detection of coronary artery disease (CAD). Segmental analysis of stress and delayed MPI was performed in 33 patients with angiographically proved CAD. They were divided into two groups : 22 patients without previous infarction (Group 1) and 11 patients with prior myocardial infarction (Group 2). Using computer analysis of MPI, 9 region-of-interests (ROIs) were set on the left ventricular image. We defined 3 indices as follows : initial uptake (%) = a ratio of ROI counts to the highest ROI counts on the exercise image ; washout rate (WR) = a ratio of [(ROI counts of the exercise image) - (those on the delayed image)] to those on the exercise image : redistribution index (ROI)= a ratio of the maximal WR to WR. Coronary arteriograms were evaluated according to Pujadas' method. In group 1, the region supplied by the coronary artery with significant stenosis showed a lower initial uptake (p < 0.005) and a higher ROI (p < 0.001) than the region supplied by the coronary artery without significant stenosis. If an initial uptake less than 83% and/or a RDI greater than 1.15 are defined as abnormal, the sensitivity for detecting CAD, including the detection of a stenosis site, was 76% and the specificity was 84%. In group 2, the sensitivity was 76% and the specificity was 80%. The mean WR could also indicate the severity of CAD. In all patients studied., the average of mean WR was 0.451 in one-vessel disease (n=18), 0.446 in two-vessel disease (n=6) and 0.305 in three-vessel disease (n=8). In conclusion, the quantitative evaluation of stress MPI using initial uptake, RDI and WR appear to be useful for noninvasive and objective diagnosis of CAD, particularly in detecting the severity and location of stenotic coronary arteries.

First pass radionuclide angiocardiography was utilized to calculate right and left ventricular ejection fraction in 74 infants and children. For the synchronization of radionuclide imaging with the cardiac cycle, the peaks and valleys of corrected ventricular time activity curve were adopted as the time reference points instead of R wave of electrocardiogram. Left ventricular ejection fractions obtained by the radionuclide technique correlated well with those derived from the contrast angiographic technique (r = 0.90), but right ventricular ejection fractions correlated less well (r = 0.74). This noninvasive technique appeared useful for evaluation of right and left ventricular ejection fraction.

Tl-201 imaging and first-pass radionuclide ventriculography (RNV) by 4 min infusion of 0.56 mg/kg dipyridamole were performed on 22 patients with coronary artery disease in order to know the relationship of myocardial perfusion and left ventricular function after dipyridamole-infusion, and thereby to define whether Tl-201 defect with dipyridamole could imply myocardial ischemia. Initial and delayed Tl-201 images were divided into anterior, apical, and infero-posterior segments, and segmental perfusion defects were categorized as reversible, fixed and no defect. RNV on the 30-degree right anterior oblique view was also divided into anterior, apical, and infero-posterior wall to be evaluated for regional wall motion by a 5 point score before and after dipyridamole. Changes in left ventricular ejection fraction (LVEF) with dipyridamole were also calculated. Normal responses of regional wall motion and LVEF to dipyridamole were established from the data of 14 normal subjects. Reversible defects were closely associated (69%) with an abnormal response of regional wall motion (score decrease of 1 or more after dipyridamole). Both fixed defects and no defects showed little association with abnormal response of regional wall motion. Moreover, 77% of the patients having reversible-defect segment showed an abnormal response of LVEF (reduction of 3% or more following dipyridamole). However, patients without reversible defect did not show an abnormal response to dipyridamole. These results suggest that dipyridamole-induced Tl-201 defects represent a myocardial ischemia which causes a reduction of ventricular function.

As a new parametric image of cerebral lesions, a map of the ratio between regional cerebral blood flow (rCBF) and the 2nd image of a series of dynamic images was proposed and tested. Three classes (poor, mild and well) were defined based on the degree of coupling between the rCBF and the new parametric image of the affected lesion. In 16 patients with cerebral infarction, those in the acute stage (within 1 week after onset) were found to belong to the poor coupling group, and the subacute group (1 to 4 weeks) showed mild coupling. In the chronic group (over 4 weeks), well coupling was observed. All patients of TIA fell into the mild coupling group. In a stimulation study with 5% CO2 mixed air, all of the well or mild-coupled lesions changed to uncoupled. These clinical findings demonstrate the characteristics of the new proposed image.

To evaluate the regional ventilation using 133Xe under different conditions, the respiratory flow and the phase with image were measured simultaneously, and sequential frames were made breath by breath. The flow signal and phase signal were converted to pulse signals by a microcomputer and stored with image data in the same file. Thus, the tidal volume and duration of each breath were measured. From sequential frames compiled breath by breath, an activity breath-number curve was made in each pixel, and the half-clearance breath number (B1/2) was calculated. The changes in conventional half-clearance time (T1/2) and B1/2 were compared under different ventilatory conditions in normal subjects and in patients with chronic pulmonary emphysema. Values of B1/2 indicated the change of turnover rate more accurately than T1/2. It is considered that B1/2 is a better parameter than T1/2 for evaluating the change in regional ventilatory function under different conditions.

Asynchronous communication was made between host (FACOM M-340) and personal computer (OLIBETTIE S-2250) to get patient's information required for RIA test registration. The retrieval system consists of a keyboard input of six numeric codes, patient's ID, and a real time reply containing six parameters for the patient. Their identified parameters are patient's name, sex, date of birth (include area), department, and out- or inpatient. Linking this program to RIA registration program for individual patient, then, operator can input name of RIA test requested. Our simple retrieval program made a useful data network between different types of host and stand-alone personal computers, and enabled us accurate and labor-saving registration for RIA test.