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In a series of 327 patients with primary GI malignancies, the occurrence of hepatic metastases was correctly detected in 70% of 113 cases by focal defects in the radiocolloid scintiscan. Only 1% of false positives were observed among the 214 patients without hepatic metastases. For these patients, the predictive value of the liver scan was 97%, and the overall accuracy, 89%. A composite test formed by disjoining focal radionuclide defects with the combination of elevated CEA and hepatomegaly, or elevated CEA and high alkaline phosphatase activity, exhibited a predictive value of 92% and an overall accuracy of 92%. Formation of such a composite test may be useful for preserving high accuracy when very strict scintigraphic criteria for metastases are employed.

The objective of this study was to clarify the relationship between cardiac sympathetic nervous function (CSNF) and left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM).Thirty-eight cases (32 males, 6 females; mean age, 56 +/- 15 y), consisting of 5 healthy control subjects, 15 patients with DCM, and 18 patients with HCM, were studied with (123)I-metaiodobenzylguanidine (MIBG) and (99m)Tc-tetrofosmin SPECT. CSNF was evaluated from cardiac uptake and washout of MIBG, whereas LV perfusion and function were evaluated from tetrofosmin uptake and wall thickening on electrocardiographically gated SPECT. As quantitative parameters of global cardiac MIBG uptake and washout, the heart-to-mediastinum ratio (H/M) and percentage washout were calculated from early and delayed planar images. As quantitative regional parameters, the regional uptake and percentage washout of MIBG were calculated from SPECT images dividing the left ventricle into 12 segments. In the tetrofosmin study, the H/M and LV ejection fraction were calculated as the parameters of global LV perfusion and function. As quantitative regional parameters, the regional uptake and wall thickening were also calculated for the 12 myocardial segments using the quantitative gated SPECT software. Multiple linear regression analysis was performed to investigate the correlations between the parameters from the 2 studies.In DCM and HCM, multiple linear regression analysis of the regional parameters showed significant correlations between LV function and CSNF (P0.0001) and between LV perfusion and CSNF (P0.0001). According to the partial correlation coefficients, washout and early uptake of MIBG were the most significant factors for predicting LV function and LV perfusion, respectively.In cardiomyopathies, CSNF was closely related to LV function. The quantitative parameters of MIBG washout could reflect cardiac functional impairment. Early MIBG uptake might be determined by myocardial perfusion in cardiomyopathies.

Cerebral blood flow(CBF) in 34 patients with bilateral chronic subdural hematoma was measured by 99mTc-HMPAO SPECT before operation. The regional CBF was measured in 26 regions of the 10 cortical regions, putamen, thalamus and cerebellar hemisphere on both sides. According to the thickness of subdural hematoma, the thicker hematoma side was measured and examined as the thick hematoma side, and the other side as the thin hematoma side. Thirty four cases with bilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 13 cases with headache(headache group), 10 cases with hemiparesis(hemiparesis group), 5 cases with tetraparesis(tetraparesis group) and 6 cases with consciousness disturbance or dementia(consciousness disturbance group), and into two groups according to the degree of midline brain shift on MRI: 14 cases of non-shifted group and 20 cases of shifted group. The average CBF of 34 patients in each region indicated a regional CBF reduction in the frontal, parietal and occipital cortices on the thin hematoma side, and in the putamen on the thick hematoma side. In the headache group, the regional CBF reduction on the thin hematoma side was found in the frontal, parietal and occipital cortices compared with the corresponding regions on the thick hematoma side, and in thalamus on the thick hematoma side. In the hemiparesis and tetraparesis groups, there was no statistically significant CBF reduction between the thick and thin hematoma sides. In the consciousness disturbance group, the CBF reduction in whole brain was remarkably significant. By the degree of the midline brain shift, the CBF reductions between the thick and thin hematoma sides were observed. Namely, in the shifted group, the CBF reductions were noted in the frontal, parietal and occipital cortices in the thin hematoma side, and in the putamen in the thick hematoma side. We concluded that the CBF reduction of bilateral chronic subdural hematoma was bilaterally found in the hemiparesis and tetraparesis groups, and which was finally observed in whole brain in the consciousness disturbance group.

Using direct measurement, we investigated entrance surface doses of patients for routine radiographs in attempt to develop evaluation methods of patient dose in order to establish the guidance level in Japan. To date, patient doses have been evaluated by calculations based on radiographic conditions, or model experiments using phantoms. Their patient doses are then evaluated based on several assumptions. Direct measurement of patient dose is difficult to perform in many patients due to its time requirement, level of expertise required and difficulty in providing an explanation of the procedure to the patient. However, such direct measurement is essential since it incorporates all aspects of radiography from the radiographic equipment used, to the actual conditions of each patient without assumption. In this study, we examined the (1) need for introducing the guidance level, (2) controversial points in the calculation method for patient dose evaluation, (3) evaluation accuracy required for introducing the guidance level, and (4) necessity for a standardized method.

Cerebral blood flow (CBF) measured by 99mTc-HMPAO SPECT before operation was studied in 60 patients with unilateral chronic subdural hematoma. The regional CBF was measured in 26 regions of the fronto-occipital 10 cortices, putamen, thalamus and cerebellar hemisphere on both sides. Sixty cases with unilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 17 cases with headache (headache group), 34 cases with hemiparesis (hemiparesis group) and 9 cases with consciousness disturbance or dementia (consciousness disturbance group), and into three groups on the basis of the degree of midline brain shift on MRI: 7 cases of mild shift group, 24 cases of moderate shift group and 29 cases of severe shift group. The average CBF in 60 patients in each region indicated that the regional CBF was reduced in frontal, occipital cortices and cerebellum on the non-hematoma side, and in putamen and thalamus on the hematoma side. In the headache group, the regional CBF reduction on the non-hematoma side was found in only frontal and occipital cortices compared with the corresponding regions on the hematoma side. In the hemiparesis group, the regional CBF was reduced in frontal and occipital cortices on the non-hematoma side and in putamen and thalamus on the hematoma side. The part of CBF reduction in both hemispheres was also noted in the hemiparesis group. In the consciousness disturbance group, the CBF reduction was markedly noted in whole brain. The CBF reductions in frontal and occipital cortices on the non-hematoma side and in putamen, thalamus and cerebellum on the hematoma side was not mutually related with the degree of midline brain shift. We concluded that the disturbance of CBF in chronic subdural hematoma was started from frontal and occipital cortices on the non-hematoma side observed in the headache group, and which was extended to putamen and thalamus on the hematoma side and a part of both hemispheres observed in the hemiparesis group. And such disturbance was finally observed as the CBF reductions in whole brain in the consciousness disturbance group.

Preoperative assessment of residual hepatic functional reserve offers important strategic information for hepatic resection. To predict the postoperative residual liver function, we assessed the value of hepatic 99mTc-diethylenetriamine pentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) clearance estimated by dynamic SPECT analysis.We investigated 114 consecutive patients with liver disease, including 55 hepatectomy cases. One minute after injection of 185 MBq 99mTc-GSA, 15 serial dynamic SPECT images were obtained every minute. The initial five sets of SPECT images were analyzed by Patlak plot to estimate the sequential initial hepatic 99mTc-GSA clearance (mL/min) as an index of hepatic function. The sum of hepatic 99mTc-GSA clearance of the segments immune from resection was categorized as predicted residual 99mTC-GSA clearance. In the hepatectomy cases, scintigraphy was performed before and 37 +/- 10 d after the operation.Good correlation was observed between the total hepatic 99mTc-GSA clearance and conventional hepatic function tests: plasma retention rate of iodocyanine green (ICG) at 15 min (ICG R15), r = -0.600, P0.0001, n = 94; plasma disappearance rate of ICG (K ICG), r = 0.670, P0.0001, n = 83; cholinesterase, r = 0.539, P0.0001, n = 121; serum albumin, r = 0.421, P = 0.0001, n = 123; and hepaplastin test, r = 0.456, P0.0001, n = 120. There was good correlation between the predicted residual 99mTc-GSA clearance and the postoperative total hepatic 99mTc-GSA clearance in patients who underwent segmentectomy or lobectomy (r = 0.84, P0.0001, n = 28) and between the pre- and postoperative total hepatic 99mTc-GSA clearance in patients who underwent subsegmentectomy (r = 0.91, P0.0001, n = 25). Five patients who had postoperative complications due to hepatic insufficiency (2 patients died of postoperative hepatic failure within 2 mo after operation) showed significantly lower predicted residual 99mTc-GSA clearance compared with the patients without complications (90.3 +/- 37.2 versus 320.9 +/- 158.8 mL/min; P0.005).The total hepatic 99mTC-GSA clearance reflected hepatic function. In addition, preoperative predicted residual hepatic 99mTc-GSA clearance was a good indicator of postoperative hepatic function and early prognosis. 99mTc-GSA dynamic SPECT is assumed to be a useful method for determining the surgical strategy in patients with hepatic tumor and especially in patients with hepatic dysfunction.

Epidemiological studies recently have indicated that magnetic fields and radiofrequency (RF) radiation have an adverse influence on the living body. The purpose of this study was to examine the safety of magnetic resonance imaging (MRI) by observing whether bacterial mutation occurs in an approximate MRI environment. We employed a GX-270 FT-NMR unit (JEOL, Ltd.) with a magnetic field strength of 6.3 Tesla. The Salmonella typhimurium tester strains used in the AMES test were exposed, and the incidence of point and frameshift mutations was evaluated. TA98 and TA7001-7006 mixed strains were used to detect frameshift and point mutations, respectively. Tester strains were exposed to the 6.3 Tesla magnetic field with RF radiation (90 degrees and 180 degrees refocusing pulses were repeated using the hydrogen Lamor frequency at 2-second intervals) for 15, 30, 45, and 60 minutes. After each exposure, the rate of revertant mutation was counted. The rates of revertant mutation in mixed strains and the TA98 strain were not statistically significant. Therefore, it was concluded that bacterial mutation is not increased by RF radiation under a 6.3 Tesla magnetic field.

Induced hypertension with angiotensin II (AT-II) and the inhibition of kininase with enalapril maleate may increase the tumor targeting of radiolabeled monoclonal antibodies (MAbs). We previously found that short-period infusion of 2.0 microg/kg/min of AT-II enhanced tumor targeting of MAb without an impact on normal tissue distribution. In this study, we aimed to optimize the manipulation with these agents, and examine the possible mechanism of their effects on MAb distribution. Effect of the manipulation on tissue circulation was assessed in mice bearing colon cancer xenografts by 201Tl and 99mTc-human serum albumin (HSA) as markers of tissue blood flow and tissue blood volume and/or vascular permeability. A dose finding study of enalapril ranging from 3 to 300 microg showed that 30 microg of enalapril in combination with AT-II infusion produced the best improvement in tumor uptake of 99Tc-HSA without altering 201Tl distribution, suggesting that the increase of vascular permeability was caused by enalapril. AT-II infusion for longer than 1 h affected renal blood flow and caused subcutaneous edema. Tumor uptake of (111)In-A7, a murine IgG1, was 1.62-fold improved 72 h postinjection (P0.001) and intratumoral distribution became uniform with 2.0 microg/kg/min of AT-II for 1 h and 30 microg of enalapril. Vessels in manipulated tumors were distended even 48 h after the cessation of AT-II infusion. In conclusion, it was suggested that persistent distension of tumor vessels and the increase of diffusive extravasation of MAb caused by short-period-induced hypertension and inhibition of bradykinin degradation produced favorable effect for the MAb distribution in tumors.

Phase III clinical study in 78 patients with hyperparathyroidism was performed to determine clinical utility of 99mTc-MIBI in the localization of hyperfunctioning parathyroid lesions. Except slight tremor in one patient, no adverse events were reported. No abnormal changes in clinical laboratories or vital signs were noted. The clinical utility of the agent was evaluated in 70 patients. Out of 108 hyperfunctioning glands, 93 (86%) were detected with 99mTc-MIBI regardless of their histology, numbers, or location. Specifically, single or ectopic lesions were detected with high sensitivity (97% and 100%, respectively). Sensitivity in 53 glands with weight data was 79%, while 94% in 36 glands above 200 mg, which is extremely high compared to the 201T1-99mTc subtraction method. Specificity in a group of PHP patients with single adenoma who underwent surgery was 100% (63/63), though in case of coexistent thyroid disease obviously interfered parathyroid images. Our study indicates that 99mTc-MIBI is a safe and excellent agent for the localization of hyperfunctioning parathyroid tissues. Especially, the fact that 99mTc-MIBI detected ectopic glands with high specificity is a great advantage over the ultrasound or 201Tl-99mTc subtraction method.

Phase III clinical study in 136 patients diagnosed or strongly suspected of thyroid, lung/mediastinum or breast cancer was performed to determine clinical utility of 99mTc-MIBI in the localization of tumors, and the results in 135 were evaluated. Except taste peculiar in 43 patients and nausea in one, no adverse events were reported. Seven abnormal changes in vital signs and 27 in clinical laboratories were noted, which were all judged as having no or unlikely relationship to the agent. Out of 177 malignant lesions, 156 (88%) were detected with 99mTc-MIBI regardless of their histology or location. Of 6 benign tumors, 3 were detected. Fifteen sites of false positive in 11 malignant tumor patients and 5 sites in 6 patients with non-tumor disease were observed. Our study indicates that 99mTc-MIBI is a safe and excellent agent for the localization of tumors. Especially, the fact that 99mTc-MIBI detected remote metastatic lesions with high sensitivity is a great advantage over the other conventional imaging modalities.

To obtain both hepatic blood flow and an index of asialoglycoprotein receptor amount by simple calculation in the asialoglycoprotein receptor imaging with 99mTc-DTPA-Galactosyl Human Serum Albumin (99mTc-GSA), we have tested the applicability of the direct integral linear least square regression (DILS) method based on a linear 3-compartment model (Bronqvist, 1984) to the kinetic analysis of 99mTc-GSA scintigraphy. DILS method can provide hepatic blood flow (k1) and the product of receptor amount and forward binding rate constant (k1k3/k2) as a receptor index, without requiring iterative calculation and initial estimates of the parameters. To compare DILS method with nonlinear least square regression (NLS) method as a standard, data from 35 patients with liver dysfunction were analyzed by both methods. The effect of the data noise to parameter estimate were simulated, and both DILS and NLS method could provide reliable parameter estimate which is relatively insensitive to the data noise. In estimated model parameters, both hepatic blood flow (k1) and the receptor index (k1k3/k2) showed significant correlation between 2 methods (r2 = 0.96, p0.0001; r2 = 0.99, p0.0001, respectively). We concluded that DILS method was comparable to NLS method in determination of the model parameters and could be useful in the asialoglycoprotein receptor imaging.

A multicenter study was undertaken in Japan to evaluate the correlation between the percentage of renal uptake of 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) estimated by the count-based gamma camera method and the blood clearance of 99mTc-MAG3. Twenty four centers were enrolled and 172 cases were finally analyzed in this study. The renal clearance of 99mTc-MAG3 (TER) was obtained by using a single blood sample taken at 44 min after injection. Comparison of TER and renal uptake provided a coefficient of correlation of 0.874; suggesting that sufficiently accurate quantification of renal function could be obtained from the renal uptake estimate by the gamma camera method. This study also showed that the comparison of renal function might be feasible among patients under the same protocols, although precise and careful consideration is required in each center.

We retrospectively reviewed the records of 11 thymoma patients to clarify the role of hemithoracic irradiation and chemotherapy for patients with thoracic dissemination at the initial presentation. Radiotherapy was administered postoperatively in all but two patients who were not candidates for surgical treatment. Radiotherapy doses ranged from 10 to 17 Gy for the entire hemithorax of the disseminated site and from 30 to 55 Gy to the primary tumor bed. Chemotherapy of various protocols was also employed preceding radiotherapy in seven cases. Cumulative 5- and 10-year survival rates were 80% and 64%, respectively. Regrowth-free 5- and 10-year survival rates were 55% and 37%, respectively. Six of the 11 patients were free from regrowth at a median follow-up interval of 60 months. The role of chemotherapy remained unclear. Acute or late sequelae were modest and acceptable. In conclusion, entire hemithoracic irradiation is justified as postoperative or definitive radiotherapy treatment for disseminated thymoma unless there is a risk of radiation pneumonitis. Further evaluation should be conducted.

We studied the abnormality of myocardial sympathetic nervous system in patients with hypertrophic cardiomyopathy using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in comparison with the parameters of other clinical examinations. In 50 patients with HCM, the heart to mediastinum 123I-MIBG uptake ratio (H/M) was significantly low and washout rate (WR) of 123I-MIBG was significantly high respectively compared with normal subjects (n = 8). H/M was negatively correlated with serum norepinephrine level, wall thickness of left ventricle, left ventricular mass index, left ventricular end diastolic pressure respectively, and WR was positively correlated with those parameters respectively. On the other hand, LF/HF calculated by spectral analysis in holter electrocardiogram was positively correlated with H/M, and negatively correlated with WR. In HCM, H/M in patients with subjective symptoms was significantly lower than that without subjective symptoms, and WR in patients with paroxysmal atrial fibrillation was significantly higher than that without paroxysmal atrial fibrillation. This study revealed that H/M and WR reflected the severity and the difference of disease type in HCM. In conclusion, 123I-MIBG contributes to evaluating more details in diagnosis and pathophysiology of HCM.

We examined a series of 21 peripheral facial palsy patients attempted to (17 Bell's palsy, 4 Hunt syndrome) with Gd-DTPA-enhanced MRI and attempted to determine the relation between prognosis and MRI findings. We divided patients into two groups based on facial palsy scores of Japanese facial nerve research: a good group (G-Group) and a bad group (B-group). The G-group scored over 20 points on the 20th day after the first visit and the B-group under 20 points. G-group consisted of 9 Bell's palsy and 1 Hunt syndrome patients, and the B-group of 8 Bell's palsy and 3 Hunt syndrome patients. The averaged facial palsy score of both groups was analyzed every week during 4 weeks. Recovery from the palsy was better in the G-group than the B-group (P0.05); the scores at the 4th week of the G- and B-groups were 32.6 +/- 15.2 and 7.8 +/- 7.4, respectively. The MRI findings of both groups were examined retrospectively. Nine of 10 G-group and nine of 11 B-group patients had abnormal contrast enhancement. The result of enhanced facial nerve segment was as follows:G-group, auditory canal 1, labyrinthine/geniculate 7, tympanic 7, mastoid 7; B-group, auditory canal 2,labyrinthine/geniculate 8,tympanic 8, mastoid 7. Our results indicate no relation between the prognosis and the MRI findings. Therefore, it is impossible to predict the prognosis of facial palsy from the results of Gd-DTPA-enhanced MRI.

Inflammatory imaging using 99mTc-HMPAO-labeled mixed leukocytes was assessed for use in treating 11 cases diagnosed as ulcerative colitis: 10 cases with total colitis and 1 with left-sided colitis. They consisted of 8 patients with relapse-remitting type and 3 with chronic continuous type. Radionuclide abdominal images were obtained at 1 hr, 4 hr and 24 hr after intravenous injection of 200 MBq prepared 99mTc leukocytes. Obvious colonic activity noted at 4 hr served as the basis for positive comparative criterion in the present study. The diagnostic efficacy of radionuclide imaging was compared with endoscopic findings (based on Matts' classification) and the clinical manifestations as reference. The sensitivity and specificity of this imaging were 83.3% and 85.7%, respectively, these values being consistent with endoscopic findings and clinical manifestations at sites of disease activity. All of positive images changed to negative after treatment by leukocyte apheresis or glucocorticoid. Based on these results, 99mTc leukocyte imaging can be used to accurately evaluate severity and treatment response in ulcerative colitis. Leukocytes may be closely related to the pathogenesis of ulcerative colitis.

We studied 50 patients with mild to moderate renal dysfunction to compare pharmacokinetics of 99mTc-MAG3 with that of 131I-OIH. After simultaneous bolus injection of both 99mTc-MAG3 and 131I-OIH, 8-point venous blood sampling was performed from 2 to 44 min post injection. Aliquoted plasma samples were counted for radioactivity along with the injected standard to obtain % injected dose/ml plasma for each tracer. Using obtained time-concentration data, classical 2 compartment model analysis was performed for both tracers to obtain various pharmacokinetic parameters, including distribution volumes (Vds), inter-compartmental rate constants, and plasma clearance. In these parameters, Vd of central compartment, Vd at steady state, central to peripheral inter-compartmental rate constant, and plasma clearance were significantly larger for 131I-OIH. In all parameters, significant correlation was found between 99mTc-MAG3 and 131I-OIH. The best correlation was seen in plasma clearance (r = 0.891, p0.0001). Plasma clearance ratio (99mTc-MAG3/131I-OIH), however, showed weak but significant negative correlation with serum creatinine, although this correlation was not likely to affect the overall correlation of clearance between 131I-OIH and 99mTc-MAG3. From these results, we confirmed that 99mTc-MAG3 clearance could be used as an alternative to 131I-OIH clearance, although pharmacokinetic behavior of 99mTc-MAG3 was not exactly the same as that of 131I-OIH.

We retrospectively reviewed the case histories of 45 patients with invasive thymoma who underwent postoperative or definitive radiotherapy. Patients in stage II or stage III were classified according to the treatment volume as follows: a) those who received irradiation confined to the primary tumor site with a generous margin (involved field group, n = 17) and b)those who received prophylactic whole mediastinal irradiation with or without entire hemithoracic irradiation (prophylactic group, n = 21). Seven recurrences were observed among the involved field group, while all patients in the prophylactic group were relapse-free and alive after a median follow-up interval of 50 months. Major side effects were observed in two patients who received entire hemithoracic irradiation. One developed severe pneumonitis resulting in lung fibrosis that required hospitalization, while the other developed nephrotic syndrome of unknown cause. We conclude that whole mediastinal irradiation with or without entire hemithoracic irradiation can be used as a treatment of choice for postoperative invasive thymoma.

We report two cases of alveolar echinococcosis (AE) of the bone, and present the computed tomography (CT) and magnetic resonance (MR) imaging findings of these surgically proven cases of AE of the ilium and clavicle. CT and MR imaging showed destruction of the ilium and clavicle, and numerous cysts of the bone and surrounding tissues. Moreover, CT and MR imaging clearly demonstrated spread of the parailiac region and superior mediastinum. CT and MR imaging were very useful in determining the extent of surgery. Our experience suggested that CT and MR imaging are complementary studies.

Forty-one patients with non-hodgkin's lymphoma at stages I and II who had received radiation therapy were reviewed to analyze the prognosis and prognostic factors, with the main focus on a comparison of elderly (age65 years) and younger patients. In terms of clinical and histological characteristics, there were no differences between the elderly and younger patients. The 5-year-survival rate (5YS) in elderly patients was 52.8%, compared with 68.6% for younger patients. In patients treated with irradiation alone, the 5YS was 49.5% in elderly patients and 22.1% in younger patients. Combination treatment consisting of irradiation and chemotherapy improved 5YS markedly to 84.9% in the younger patients, while no apparent improvement was seen in the elderly patients, in whom 5YS was 54.1%. Using Cox's multiregression life table, two prognostic factors, the presence of symptoms and LDH, were extracted and found to have a significant influence upon the survival of the elderly patients. Complete response was 90.2% in the elderly patients, although relapse was seen in 54.1% of the complete responders. Relapse occurred overwhelmingly outside the irradiated regions. Since the prognosis of elderly patients could not be improved with the current chemotherapy regimen, some different regimen must be established to lower the high relapse rate in the area outside the irradiated field.

Presently, radionuclide imaging in hepatobiliary disease is mainly used to evaluate the functional aspect in hepatobiliary disease. For the evaluation of hepatic function, three kinds of radiopharmaceuticals are now commercially available: these are the Kupffer-cell oriented radiotracer of 99mTc-colloid, the hepatocyte oriented radiotracer of 99mTc-PMT, and the receptor-binding radiopharmaceutical of 99mTc-GSA. These radiopharmaceuticals must be properly used, according to the purposes. 99mTc-PMT can be used to determine the degree of functional disorder in acute hepatic disease and evaluate the severity of diffuse hepatic disease, whereas 99mTc-colloid can effectively evaluate the potential etiology of the disease process and its chronicity. And 99mTc-GSA may also be used to evaluate the severity of the disease. In particular, the hepatic functional reserve must be evaluated with 99mTc-GSA. The biliary patency from the intrahepatic bile canaliculi to the common bile duct can be effectively evaluated with 99mTc-PMT. The diagnosis of acute cholecystitis is most reliably made by radionuclide imaging. And radionuclide imaging is sometimes to be used for the differentiation of cholestasis. In particular, the discrimination among the disease entities of chronic intermittent intrahepatic cholestasis including primary biliary cirrhosis, primary sclerosing cholangitis and juvenile intrahepatic bile duct hypoplasia can be made. Moreover, it is also be used in evaluating constitutional hyperbilirubinemia, biliary leakage, infantile jaundice and gallbladder or syphinctor Oddi motor dysfunction.

We investigated the usefulness of gallium scintigraphy and its importance in the choice of a treatment method for Crohn's disease. The subjects for the study were 30 patients diagnosed as Crohn's disease. After intravenous injections of 67Ga-citrate 111 MBq, planar and SPECT images were taken at 48 and 72 hrs. The overall positive rate was 42.1%, and among the positive cases, 78.6% required surgical treatment. On the other hand, surgical treatment was only performed in 18.8% of the negative cases, which was significantly low percentage. However, since 75% of the cases, in whom surgical treatment was performed, showed preoperative positive 67Ga results, positive cases detected by 67Ga scintigraphy were considered to be high-risk cases requiring surgical treatment.

We synthesized four new tumor imaging agents, 99mTc-labeled metalloporphyrins (99mTc-STA-R12, -STA-R21, -STA-RN101 and -ATN-12) for the tumor imaging. We compared the differences of tumor imaging potency among these agents in CDF1 mice implanted with colon 26 tumor. Tumor images with these agents were obtained by using digital gamma-camera (RC135-E, Hitachi, Tokyo) and the biodistributions were analyzed by computerized medical radionuclide imageanalyser (RP-200, Hitachi, Tokyo). The highest tumor organ ratio and the excellent tumor image were obtained by 99mTc-STA-R12 (13,17-Bispropanyl aspartic acid-3-ethenyl-8-[N,N',N",N"-tetrakis (carboxylmethyl-2,7,12,18-tetramethyl-porphyrinato]-manga nes e(III). The maximum concentration of 99mTc-STA-R12 in tumor tissue was observed at around 120 minutes after i.v. injection. On the contrary, the uptake rates of other organs and tissues such as liver, brain, muscle, lung, bone and blood continuously decreased. The rapid accumulation of STA-R12 in cancer tissue and the clearance from other tissue suggested a potential usefulness of this compound for tumor imaging agent.

In order to assess prognostic factors and therapeutic methods, 104 patients (aged 6 to 89; mean age 57.4; male 68, female 36; stage: I 45, II 59) with clinical stages I and II non-Hodgkin's lymphoma treated at our department between 1977 and 1991 were reviewed. Factors, such as sex, age, clinical stage, primary site, presence of general symptoms, pathology, tumor size, LDH and therapeutic methods (radiotherapy alone; initial radiotherapy plus chemotherapy; initial chemotherapy plus radiotherapy) were calculated by univariated analysis to determine important factors influencing the survival. The survival of patients with symptoms and large tumors (more than 70 mm) was shorter than that of those without symptoms and with small tumors (5 years survival: symptom B 17.9%, A 68.2%, p0.001; tumor more than 70 mm 44.0%, less than 70 mm 67.1%, p0.05). Regarding therapeutic methods, radiotherapy alone achieved a 5-year survival rate of 37.1%; initial radiotherapy plus chemotherapy had 64.6% and initial chemotherapy plus radiotherapy 78.5%, but a significant difference was noticed only between radiotherapy alone and initial chemotherapy plus radiotherapy (p0.001). These results suggest that important factors influencing the survival are presence of general symptoms, tumor size and therapeutic methods.

201Tl single photon emission computed tomography (SPECT) was evaluated in 170 patients suspected of having a malignant pulmonary lesion greater than 20 mm in diameter on the surgical specimen. Delayed SPECT (at 3 h after injection) visualized all of the 147 malignant pulmonary lesions and 16 of the 23 (69.6%) benign pulmonary lesions, and generally exhibited the lesion more clearly than the early SPECT images (at 15 min after injection). There was no significant difference in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) among the various histological groups except between the adenocarcinoma and large cell carcinoma groups (P0.05), and no difference was noted between the malignant and benign lesions. However, in retention index (degree of retention in the lesion) a significant difference was noted between the malignant and benign lesions (P0.01), although there was no significant difference in this index among malignant different histology groups. These results indicate that this method is useful for visualizing malignant pulmonary lesions greater than 20 mm in diameter to exclude the possibility of malignancy in the lesions when no abnormal 201Tl accumulation is observed. When the lesion shows abnormal 201Tl accumulation, the retention index seems to help differentiate malignant from benign lesions.

The utility of 99mTc-mercaptoacetyltriglycine (MAG3) with studied clinically. In the renography obtained with 99mTc-MAG3, the abdominal aorta and the common iliac arteries were clearly visualized in the vascular phase. Due to less background activity and high target to background ratio, the quality of 99mTc-MAG3 image was superior to that of 123I-OIH or 99mTc-DTPA image. The parameters on the renogram including Tmax, T2/3, and T1/2 were compared. The correlation of Tmax and T2/3 or T1/2 were not significant between 99mTc-MAG3 and 123I-OIH. Another parameter of C20/Cmax, where C20 and Cmax are renal activities at 20 min after injection and at Tmax respectively, showed an excellent correlation between 99mTc-MAG3 and 123I-OIH. Using C20/Cmax, pattern of renogram can be characterized numerically. Concerning about the relation between C20/Cmax and renogram pattern, standard renogram pattern showed the C20/Cmax value of less than 0.4, while hypofunctioning pattern showed more than 0.5. The correlation coefficient between the renal uptake of 99mTc-MAG3 and 123I-OIH was 0.880 with a correlation plot: "Y = 1.16X-0.043", where X and Y represent renal uptake of 99mTc-MAG3 and 123I-OIH, respectively. It can be concluded that 99mTc-MAG3 is useful renal imaging agent as an alternative to 123I-OIH, in order to evaluate the proximal tubular function and calculate ERPF.

We evaluated 67Ga SPECT in the differentiation of mass-like lesions in the orbital and ocular areas. A two-headed SPECT system equipped with parallel-hole collimator was used. 67Ga SPECT demonstrated three dimensionally the extent of tumors found by CT and MRI. 67Ga SPECT was especially useful in the assessment of localized lesions in and around the lacrimal gland. In a total of 43 patients studied, the overall accuracy of 67Ga SPECT in diagnosing orbital and ocular lesions was 72%. Sixteen of 21 malignant lesions (76%) showed true positive findings and 15 of 22 benign lesions (68%) showed true negative findings. All seven malignant lymphoma lesions showed true positive findings. One of four cases of malignant melanoma was not visualized. This lesion was less than 15 mm in diameter. None of the three cases of retinoblastoma was visualized, regardless of tumor size. Four of seven cases of pseudotumor or pseudolymphoma showed false positive findings. The differentiation of pseudotumor and pseudolymphoma from malignant lymphoma seemed to be difficult. We conclude that 67Ga SPECT is useful in the differentiation of lesions in the orbital and ocular areas and that evaluation of the extent of malignant lesions can be improved by comparing the findings obtained by morphological diagnostic modalities.

A 39-yr-old man with an autonomously functioning thyroid carcinoma is presented. Only 17 similar cases have been reported in the literature. The patient had unilateral Graves' ophthalmopathy. He was euthyroid as reflected by normal TSH concentration, whereas the results of a T3 suppression test established the presence of autonomous thyroid function. A thyroid scan with (123)I revealed a hot nodule corresponding to the location of a papillary carcinoma and remained substantially unchanged after T3 administration. The hyperfunction of the carcinoma itself was clearly confirmed by the intense concentration of (131)I within the tumor on microautoradiograms. While a hot nodule on radioiodine scan is unlikely to be malignant, the possibility of carcinoma should not be overlooked.

Using data from 17 patients with liver cirrhosis and 3 patients with fatty liver, we have compared the utility of 3 hepatic imaging agents in the evaluation of hepatic functional reserve. Evaluated here were 99mTc-galactosyl human serum albumin (GSA) which is a new ligand for hepatic binding protein, 99mTc-N-pyridoxyl-5-methyl tryptophan (PMT) of a hepatobiliary agent, and 99mTc-Sn colloid. In each patient, we performed these 3 imaging studies within a week and also examined hepatic function tests (indocyanine green test, hepaplastin test, choline-esterase, etc). In each imaging study, serial images and dynamic data were obtained after the injection of 99mTc-GSA (185 MBq/3 mg), 99mTc-PMT (185 MBq), or 99mTc-Sn colloid (185 MBq). Using the obtained dynamic data, we analyzed the liver kinetics of the 3 agents based on 1 compartment model with 3 parameters (hepatic clearance, hepatic excretion rate, non-specific volume of distribution). From fitting the liver and heart data to this model, three unknown parameters were determined. Patlak plot was also applied in order to estimate liver uptake rate. Both curve fitting and Patlak plot could determine appropriate parameters in every study. In 99mTc-GSA, a nonlinear 3 compartment model was also applied in order to estimate hepatic blood flow, liver receptor density, and affinity of receptor-GSA binding separately. Using the obtained parameters, we analyzed the correlations between the parameters and the results of hepatic function tests. In all of the parameters, those obtained from 99mTc-GSA imaging showed the most significant statistical correlation with the results of hepatic function tests. From the present results, 99mTc-GSA imaging was concluded to be the best for evaluation of hepatic functional reserve.

A radionuclide imaging with Tc-99m HMPAO labeled leukocyte was performed in order to determine its clinical usefulness in inflammatory disease. The mixed leukocyte isolated from 40 ml of whole blood containing 5 ml of acid citrate dextrose A and 7 ml of 6% hydroxyethyl starch was incubated with 370 MBq (10 mCi) of Tc-99m HMPAO at 37 degrees C for 30 minutes. Because the labeling efficiency of Tc-99m HMPAO labeled leukocyte was 60.2 +/- 6.3%, the procedure of washing Tc-99m, leukocyte with 5 ml of physiological saline was necessary before intravenous injection, in order to remove the unlabeled Tc-99m HMPAO. The recoveries of Tc-99m leukocyte in the blood after intravenous injection were 41.1 +/- 6.7% at 5 minutes, 33.4 +/- 2.1% at 30 minutes, and 27.2 +/- 3.4% at 2 hours after injection. Moreover, the labeled leukocyte was not stained with trypan blue. Therefore, the biological activity of the Tc-99m leukocyte was maintained as that of In-111 oxine labeled leukocyte. In the 39 patients with clinical suspicion of inflammatory disease including 15 patients with acute and chronic infectious disease where both Tc-99m leukocyte and Ga-67 citrate imagings were performed, the sensitivity, specificity and accuracy for infectious disease were 47%, 100% and 79% with Tc-99m leukocyte, and 67%, 79% and 74% with Ga-67 citrate. These results suggest that Tc-99m HMPAO labeled leukocyte imaging is promising for evaluating inflammatory disease because of the much higher specificity, the ready availability of Tc-99m HMPAO, the good image quality, and the lower radiation dose to the patient.

The diagnostic value of In-111 transferrin abdominal imaging was studied in 17 patients with clinical suspicion of protein-losing gastroenteropathy, compared to that of alpha-1-antitrypsin fecal clearance test. The presence or absence of gastrointestinal protein-loss was finally decided based on the result of alpha-1-antitrypsin fecal clearance test (normal range, less than 13 ml/day) or of protein content measurement on the gastric juice (normal range, less than 71 mg/dl). In-111 transferrin was labeled in vitro. After intravenous administration, serial anterior abdominal images were obtained. All seven patients with a value equal to or more than 20 ml/day on the alpha-1-antitrypsin clearance test and two out of ten patients with a value less than 20 ml/day showed definite intestinal activity demonstrating protein-loss, and the loss-site was estimated by observing the movement of radiotracer within the bowel lumen. The patients with severe protein-loss showed the intestinal activity on the early image. In the patients with milder protein-loss, on the other hand, the activity was noted on the later image. All two patients with positive In-111 transferrin imaging and negative alpha-1-antitrypsin test were associated with protein-losing gastropathy, where a value of alpha-1-antitrypsin clearance was not increased because of denatured alpha-1-antitrypsin by acidic gastric juice and pepsin. These results suggest that In-111 transferrin abdominal imaging can be more useful for the diagnosis of protein-losing gastroenteropathy, because of its capabilities to evaluate the patients with gastropathy as well as to estimate the loss-site.

We administered both per-rectal thallium-201 (201Tl) and technetium-99m pertechnetate (99mTc) to patients with liver diseases in order to understand the abnormalities of inferior mesenteric vein (IMV) blood flow circulation. As 201Tl heart-to-liver uptake ratio (H:L), reflecting the degree of portal-systemic shuntings (PSS), increased, the visualization of IMV in general became poor on 99mTc scintigrams. 201Tl H:L in the group with no visualization of IMV on 99mTc scintigrams was significantly higher than in the group with clear visualization of IMV (p less than 0.001). However, there were patients who showed IMV visualization among those with high 201Tl H:L. In these patients, it was considered that IMV blood flowed in the normograde direction, escaping mainly through PSS at the upper part of the portal system, and resulting in elevated H:L. In the patients without IMV visualization, IMV blood flowed in the retrograde direction, escaping mainly through collaterals at the lower part of IMV. Inferior vena cava (IVC) was visualized on 99mTc scintigrams in some patients without IMV visualization, indicating the presence of collaterals from the distal part of IMV to IVC. Per-rectal studies using these two radiotracers can afford us useful informations on the abnormalities of IMV blood flow hemodynamics in patients with liver diseases.

The neck uptake ratio of 99mTcO4- was measured using a gamma camera and pinhole collimator. The patient was sit 2 m apart from the collimator surface and radioactivity was counted 20 minutes after injection. The whole body count with lead shield (Cc) and without shield (Cd), and natural background count (CBG) were measured. As the shield was utilized the B filter for conventional thyroidal 131I uptake test (lead plate of 1.3 cmx10 cmx10 cm) and it was placed over the anterior neck to cover the thyroid gland at the measurement of (Cc). Then 99mTcO4- neck uptake ratio was calculated as following: (formula: see text) The mean values were 5.3%, 4.5%, 3.1%, 11.2% and 20.7% in the group of euthyroid, hypothyroid, subacute thyroiditis, hyperthyroid state with chronic thyroiditis and Graves' disease, respectively. This method is very convenient and simple to perform following scintigraphy of the thyroid gland with pinhole collimator.