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The aim of this study was to evaluate the reproducibility of 99Tcm-mercaptoacetyltriglycine (99Tcm-MAG3) clearance and to compare it with that of 131I-orthoiodohippurate (131I-OIH), which is widely used in clinical practice. Twelve young healthy volunteers with a mean age of 23.4 years (range 19-28) were enrolled in the study. The investigations were repeated at an interval of 1 month under similar physiological conditions. Each volunteer received a simultaneous injection of 99Tcm-MAG3 and 131I-OIH that was commercially available in an already labelled form. Blood samples were obtained at 44 and 104 min post-injection. Clearance values were calculated using the two-sample method. The mean (+/- S.D.) change from the first to the second measurement was -7.1 +/- 11.1% for 99Tcm-MAG3 and 1.7 +/- 13.6% for 131I-OIH. There were no significant differences between the first and the second measurements of 99Tcm-MAG3 and 131I-OIH clearance, respectively. 99Tcm-MAG3 clearance was shown to be very similar to that of 131I-OIH in healthy volunteers.

SPECT imaging with I-123 IMP or Tc-99m HMPAO was performed in two patients with Creutzfeldt-Jakob disease to evaluate abnormalities in brain perfusion. In the first patient, there was decreased perfusion of the left frontal, parietal, and temporal lobes. CT and MRI were negative. In the second patient, there was patchy perfusion and slightly decreased perfusion of the right hemisphere. MRI revealed slight brain atrophy and bilateral high intensity areas in the basal ganglia on T2 weighted images. Subsequent SPECT imaging revealed severely decreased perfusion of the entire brain. Subsequent MRI demonstrated severe brain atrophy.

The authors present a case of extensive soft-tissue radioactivity visualized on both 99mTc-MDP and 201Tl-chloride scintigrams in a patient with dermatomyositis and colon cancer. Incidentally, diffuse and intense uptake of 99mTc-MDP was observed in the shoulder girdles, anterior chest wall, psoas muscles, both proximal thighs and right lower limb, corresponding to the sites of symptomatic muscles, even though skin lesions were limited and no calcification was detected on radiographs. Moreover, 201Tl-chloride was also intensely accumulated in nearly the same sites as the symptomatic muscles as shown on the 99mTc-MDP bone scintigrams. Whole-body scintigraphy with 99mTc-MDP and 201Tl-chloride is a useful tool to detect occult muscle lesions with dystrophic calcification and hyperemia in dermatomyositis.

Simultaneous assessment of regional adrenergic activity and perfusion with 123 I-meta-iodobenzylguanidine ( 123 I-MIBG) and 201 Tl in various organs was performed in 13 patients with congestive heart failure (CHF) and 13 subjects without heart failure. In order to reduce the crosstalk of 201 Tl to the 123 I energy window to less than 5%, a dose of 123 -MSBG more than five times greater than that of 201 Tl was administered following 201 Tl scintigraphy. Regional uptake of 201 Tl (% dose) was significantly increased in the heart (left ventricle) and lung (both P < 0.01) in the patients with CHF. The increased global cardiac uptake could have been related to the enlarged left ventricle. The patterns of regional uptake of 123 I-MIBG (% dose) at 15 min were similar to those of 201 Tl, suggesting that early 123 I-MSBG uptake could in part depend on regional perfusion in both groups. At 3 h, regional uptake of 123 I-MIBG was significantly increased in the heart, lung and kidney (all P < 0.01) in the patients with CHF. The delayed 123 I-MIBG uptake indicates the degree of neuronal accumulation of the tracer, and therefore reflects adrenergic activity. Interestingly, the cardiac 123 I-MIBG (adrenergic activity) to 201 Tl (unit of perfusion) ratio decreased significantly in the heart (P < 0.01) but increased significantly in the kidney (P < 0.01) in the patients with CHF compared with the control group. Cardiac 123 I-MIBG washout was also significantly increased in the CHF patients. Moreover, the cardiac 123 I-MIBG : 201 Tl ratio was negatively correlated with plasma norepinephrine concentration (r = -0.74, P

To determine the effect of exercise intensity on regional blood flow in exercising and resting leg muscles and organs, we assessed relative changes in the regional distribution of 201Tl during one-leg ergometer exercise and at rest by whole-body scintigraphy as an estimate of regional blood flow changes in 10 healthy males. The regional 201Tl activity was expressed as a percentage of the whole-body activity, and relative changes in each region were compared to those at the anaerobic threshold (AT) and at peak exercise. In the legs, the distribution of 201Tl in the exercising thigh and calf increased significantly at the AT to 390.7 and 219.2% respectively of resting levels (both P < 0.01), but remained unchanged the resting thigh from rest to peak exercise. Conversely its distribution in the resting calf decreased significantly at the AT to 60.0% of the resting level (P < 0.01). However, there were no significant differences between AT and peak exercise. In the organs, the distribution of 201Tl in the lung, liver, spleen and kidneys decreased significantly at the AT to 88.4 +/- 10.4%, 67.0 +/- 11.5%, 62.4 +/- 11.8% and 67.0 +/- 8.6% respectively of resting levels (all P < 0.01). Redistribution of blood flow to the exercising leg occurs predominantly during mild to moderate exercise. Therefore, blood flow in the leg during strenuous exercise depends primarily upon an increase in cardiac output. The splanchnic organs are the major sources of redistribution.

I-131 MIBG, a specific radiopharmaceutical agent for scintigraphic imaging and treatment of pheochromocytoma and neuroblastoma may be useful for detection of apudomas. Scintigraphy with I-123 radiolabeled MIBG was performed in a patient with metastatic carcinoid tumor from the rectum. I-123 MIBG scintigraphic findings showed multiple areas of abnormal tumor uptake of hepatic and bone metastases from the rectal carcinoid. Bone scintigraphy demonstrated multiple metastatic lesions. Computed tomography revealed multiple solid tumors of the liver. This report describes accumulation of I-123 MIBG in the liver and bone metastases from the rectal carcinoid. Radioiodine MIBG scintigraphy may be useful for detecting metastatic lesions, for evaluating postoperative recurrence, and also for the treatment of the carcinoid tumor.

A patient with osteomalacia secondary to vitamin D deficiency after gastrectomy for gastric cancer is presented. Initial bone scintigrams showed both asymmetric and symmetric focal areas of intense uptake due to pseudofractures reminiscent of bone metastases. Radiographs only confirmed the presence of pseudofractures at some, but not all, of the abnormal sites demonstrated by bone scintigraphy. At first, metastatic bone disease was suspected. However, the appearance of repeated bone scintigram was normalized after treatment with vitamin D. A diagnosis of osteomalacia was established. The present case serves to illustrate that symmetric focal lesions are important features of pseudofractures secondary to osteomalacia, and comparison with radiographs and repeated bone scintigraphy are necessary in distinguishing between bone metastases and pseudofractures.

The authors present a case of basilar artery migraine in a 33-year-old woman who was initially misdiagnosed as having a cerebrovascular or mental disorder and subjected to MRI and cerebral angiography, which, however, did not show any pathologic findings. During admission to the university hospital, she lost consciousness. An emergency Tc-99m HMPAO brain SPECT showed a significant decrease of regional cerebral blood flow in the right temporal and occipital cortices, and right cerebellar hemisphere, where regional cerebral blood flow was decreased by 10-24% as compared to the left side. The second brain SPECT during a symptom-free phase showed the reversion of regional cerebral blood flow to normal in these areas. Basilar artery migraine was diagnosed by the finding of reversible ischemia in the territory of the right basilar artery on brain SPECT images and the clinical picture.

To validate the use of 201Tl distribution as an estimate of regional blood flow in the legs, 201Tl leg uptake was compared by whole body scintigraphy and simultaneously measured leg blood flow by plethysmography during one-leg exercise in 11 male subjects. 201Tl leg uptake ratio and leg blood flow ratio were also compared to exclude the effect of cardiac output variation in each subject. There was a good correlation between 201Tl leg uptake and leg blood flow (r = 0.85, P < 0.01, y = 0.28x + 1.00). Moreover, there was a highly linear correlation between these ratios (r = 0.98, P < 0.01, y = 0.75x + 0.13), although the 201Tl leg uptake ratio somewhat underestimated the leg blood flow ratio as exercise became strenuous. It is concluded that 201Tl leg uptake reflects regional blood flow in the legs during exercise.

We report an experience of percutaneous transcatheter embolization to posttraumatic arterial priapism in a child. Priapism was successfully treated with this method. Angiography with subsequent selective embolization should be considered to be the treatment of choice for arterial priapism in children as well as in adults when less invasive treatments fail.

Wandering spleen is the term commonly applied to splenic hypermobility that results from laxity or maldevelopment of its suspensory ligaments. It comes to medical attention usually as an abdominal mass, or when the spleen undergoes torsion. Diagnosis on clinical grounds alone is rarely made, and ultrasonography, CT and MRI findings have no specific characteristics for this condition. 99mTc-labeled colloid taken up by the spleen may provide a specific diagnosis. We report a case of wandering spleen, in which the preoperative diagnosis was made on the basis of sequential liver-spleen scintigraphy with 99mTc-Sn-colloid and blood-pool scintigraphy with 99mTc-RBC. This is a rare case, in which hypermobility was assessed by sequential 99mTc-Sn-colloid scintigraphy, and to our knowledge, is the first case in which 99mTc-RBC scintigraphy provided useful information on splenic blood volume and its location.

Seventy-one-year-old man had a liver mass. He lived in Hokkaido, where there is an epidemic of hydatic disease. Abdominal US image showed an echogenic mass. CT revealed a low density mass with an unclear margin. A 99mTc-Sulfur colloid liver SPECT study was performed to detect the liver mass. The SPECT scan was done after intravenous administration of 5 mCi of 99mTc-sulfur colloid, and it revealed a lack of uptake in the liver mass. The liver SPECT findings were correlated with subsequent CT and US imaging. Echo-guided biopsy showed a PAS-positive cuticle layer of echinococcosis in the necrotic tissue. This is the first report of a case of detection of hepatic alveolar echinococcosis by means of a colloid liver SPECT imaging procedure.

Two patients with malignant melanoma were evaluated using Tl-201 scintigraphy. Planar scintigraphy showed tumor accumulation, and SPECT Tl-201 imaging revealed exact tumor localization. The findings indicate the utility of Tl-201 to detect the primary lesion and to identify postoperative recurrence in malignant melanoma.

F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) imaging is a useful modality in the detection of various tumors, including gastric cancer. We evaluated a patient with gastric neuroendocrine carcinoma with multiple liver and lymph node metastases using F-18 FDG PET imagin

To improve the detectability of gastrointestinal (GI) bleeding, we have developed a new method, 'sequential subtraction scintigraphy' (SSS) with 99Tcm-labelled red blood cells (RBC). Sequential subtraction scintigrams were obtained by subtracting 5 min interval images from each other using a digital gamma camera. With this method, we are able to detect the bleeding site and calculate the bleeding rate earlier because of the lower background activity. The results of the present study demonstrate that the minimum detectable bleeding rate was 0.05 ml min-1 in both a phantom and an animal model. The minimum detectable activity volumes within 10 min were 0.5 ml by SSS and more that 3 ml by conventional non-subtraction scintigraphy (CNS). The bleeding rates calculated with the subtraction method correlated well with the actual syringe pump rates. The detectability of GI bleeding by SSS and CNS in animal models was compared using the area under receiver operator characteristic (ROC) curves. The results showed that SSS significantly increased the area under the ROC curves from 0.55 +/- 0.05 to 0.79 +/- 0.04 for the 10 min image set and from 0.65 +/- 0.05 to 0.83 +/- 0.04 for the 30 min image set (Z = 5.45, P < 0.0001 and Z = 4.36, P < 0.0001, respectively). These results suggest that sequential subtraction scintigraphy with 99Tcm-RBC is an effective method for the early detection of GI bleeding when compared with the conventional non-subtraction method.

Brain SPECT in a patient with Wilson's disease revealed deceased perfusion in the areas of the basal ganglia and cerebellum. CT showed no abnormalities. Brain SPECT with Tc-99m HMPAO showed perfusion abnormalities.

Objective : The purpose of our study was to characterize the relationship between signal intensity on STIR MRI, histology, and liver function. Materials and Methods : MRI was performed in 39 patients with chronic liver diseases [chronic persistent hepatitis (CPH), chronic active hepatitis (CAH), liver cirrhosis (LC)] and 11 patients without liver dysfunction (normal). Results : On STIR images, very low signal intensities compared with those of the spleen were seen in all 11 normal livers (100%), and brighter intensities were seen in chronic diffuse liver diseases (10 patients with CPH, 11 patients with CAH, and 18 patients with LC) (100%). The higher the signal grade on STIR images (moderate, marked), the more advanced was the chronic diffuse liver disease (p < 0.02). The levels of serum glutamic-oxaloacetic and glutamic-pyruvic transaminase increased in parallel with increasing signal intensity on STIR images (both p < 0.01). Conclusion : We found that the signal intensity of liver on STIR images appeared to be associated with the degree of histologic and/or clinical severity in patients with chronic liver disease.

To improve the early detectability of gastrointestinal (GI) bleeding, we have developed a new subtraction scintigraphic technique using in vivo labeled 99mTc red blood cells (RBC). Use of this new sequential subtraction method every 5 min makes it possible to detect early the bleeding site and calculate the bleeding rate. In phantom experiments, focal activity was detected on subtraction images at pump rates of more than 0.20 ml/min at any urethane thickness, but was negative on conventional scintigrams. The calculated pump rate by the subtraction method correlated well with the actual syringe pump rate (y = 1.07x - 0.02, r = 0.99, p0.01) in the case of an 8-cm urethane board as an abdominal wall. Twenty-four of 50 patients with suspected GI bleeding were confirmed to be positive within 24 hr. The subtraction method showed 15 true positive and 2 false positive cases within 60 min. On the other hand, the conventional scintigraphic method showed only 7 true positive and 1 false positive cases. Sensitivity of the subtraction method was 62.5%, which was significantly higher (p0.05) than that of the conventional scintigraphic method (29.2%). These results suggest that sequential subtraction scintigraphy with 99mTc-RBC is an effective method for the early detection of GI bleeding and shortening the examination time as compared with conventional scintigraphy.

We report the case of a 58-year-old male with cholecystocolic fistula and hepatic abscess that were not diagnosed by routine radiologic examinations, but concurrently detected by hepatobiliary scintigraphy with 99mTc-PMT, and confirmed at operation. Hepatobiliary scintigraphy is noninvasive and useful in the detection of a biliary enteric fistula and lesions about related organs. Concurrent detection of cholecystocolic fistula and hepatic abscess on hepatobiliary series is of great clinical value in planning surgical intervention.

There have been few reports to evaluate the diagnostic value of Ga-67 citrate imaging in renal neoplasms, and none of these studies have described a tumor thrombus in the inferior vena cava from renal cell carcinoma. The authors present an unusual case of a 48-year-old woman with renal cell carcinoma extension into the inferior vena cava, which was incidentally detected by Ga-67 citrate imaging and confirmed by findings at autopsy

A patient with neuro-Behcet disease is described. SPECT using Tc-99m HMPAO was performed to evaluate brain perfusion. The brain SPECT revealed decreased perfusion in the right frontal, parietal, temporal, and occipital lobes. MRI showed high intensity lesions in the white matter in the right periventricular centrum semiovale and frontal region on T2 weighted images. Gray matter abnormalities were evident on brain SPECT, but not on MRI. Brain SPECT using Tc-99m HMPAO may provide useful clinical information on regional cerebral cortical abnormalities associated with neuro-Behcet disease.

Acute renal failure after exercise with frank pain and patchy renal vasoconstriction is a clinical syndrome that occurs in young, previously healthy persons. The authors describe a 24-year-old man who had this syndrome. CT scan showed wedge-shaped contrast enhancement of both kidneys, which suggested patchy renal vasoconstriction. Tc-99m MDP imaging revealed diffuse increased uptake of both kidneys. After renal function was improved, Tc-99m MDP imaging showed normal uptake of both kidneys. Acute renal failure due to acute tubular necrosis was confirmed by renal biopsy. The authors conclude that Tc-99m MDP may be useful in evaluation of acute renal failure after exercise with flank pain and patchy renal vasoconstriction due to acute tubular necrosis.