Gliosarcoma with thallium-201 SPECT.

Thallium-201 (201Tl) chloride scintigraphy is the imaging method use for the detection of various tumors including glioblastoma, but only limited information on 201Tl uptake in gliosarcoma is available. We investigated a patient with gliosarcoma by means of 201Tl single-photon emission computed tomography (SPECT) and MRI. SPECT imaging revealed high 201Tl uptake in the tumor, which was closely correlated with contrast-enhancement on MRI. These results suggest that SPECT with 201Tl may be useful for detecting gliosarcoma and provide physiological information on this tumor.

A novel technique using biplane cine magnetic resonance imaging to evaluate left ventricular volume in children.

The purpose of the study is to determine the feasibility of a novel simplified technique using cine magnetic resonance imaging (MRI) to assess left ventricular (LV) volume and ejection fraction (EF) validated by comparison with biplane LV angiography. Previous MRI studies to assess LV volumes have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, we developed a simplified imaging approach using biplane cine MRI and imaging planes aligned with the intrinsic cardiac axes of the LV. We studied 20 children (aged 4 months to 10 years) with various heart diseases. The accuracy of cine MRI was compared with that of LV angiography in all patients. LV volumes were calculated using Simpson's rule algorithm, for both MRI and LV angiography. LV volumes determined from MRI were slightly underestimated but correlated reasonably well with angiographic volumes (LVEDV: Y = 0.88X + 1.58, r = 0.99, LVESV: Y = 0.73X + 1.03, r = 0.98). Most importantly, even in patients who had abnormal ventricular curvature such as in tetralogy of Fallot, MRI determined LV volumes correlated well with angiographic values. The MR study was completed within 35 min in all patients. In conclusion, simplified biplane cine MRI, using the intrinsic LV axis planes, permits noninvasive assessment of LV volumes in views comparable to standard angiographic projections and appears practical for clinical use in childhood heart disease since the scan and analysis times are relatively short.

Radiotoxicity after iodine-131 therapy for thyroid cancer using the micronucleus assay.

UNLABELLED: The purpose of the present study was to evaluate the degree of cytological radiation damage to lymphocytes after 131I therapy using the cytokinesis-blocked micronucleus assay. The chromosomal damage to lymphocytes induced by 131I in vivo should result in augmentation of the cells with micronuclei. METHODS: We studied 25 patients with differentiated thyroid carcinoma who were treated with 3.7 GBq of 131I. Isolated lymphocytes collected from patients 1 wk after therapy were harvested and treated according to the cytokinesis-blocked method of Fenech and Morley. The micronucleus number of micronuclei per 500 binucleated cells were scored by visual inspection. As controls, lymphocytes from the same patients before therapy were also studied. In an in vitro study, lymphocytes from three patients at least 3 mo after therapy were exposed to doses varying from 0.25 to 1 Gy and studied with the same method. RESULTS: The mean number (mean +/- s.d.) of micronuclei after treatment was significantly increased (p < 0.05) as compared to control subjects (15.7 +/- 2.7 vs. 5.4 +/- 1.4). Since there was an interval ranging from 6 to 20 mo (mean 11.8 mo) between the present and the last radioiodine therapy, no significant effect on the frequency of micronucleus with cumulative radiation exposure of 131I to lymphocytes was detected. Internal radiation absorbed doses estimated for 25 patients were 0.33 +/- 0.09 Gy in this external irradiation study. CONCLUSION: The relatively low frequency of lymphocyte micronuclei induced by 131I in vivo and lack of significant effect on the frequency of lymphocyte micronuclei with cumulative 131I supported the contention that short-term nonstochastic damage of this therapy with 3.7 GBq of 131I in thyroid cancer patients is minimal and reversible.

Malignant gastrointestinal stromal tumor of the small intestine: radiologic-pathologic correlation.

Neoplasms of the small intestine are very rare. Gastrointestinal stromal tumors (GISTs) are one of the new undifferentiated stromal tumors of the gastrointestinal tract diagnosed by immunohistochemistry. We present a case of a malignant GIST arising from the small intestine and report the radiologic characteristics of the tumor and pathological correlation. CT showed a very large, enhancing mass with extensive central necrosis located on the mesenteric side of the jejunum. A perforation into the jejunal lumen was observed by upper GI series. MRI showed a very large tumor which was hypointense on T2-weighted images. Ultrasound revealed a mixed solid and cystic mass. Grossly, the tumor was solid peripherally with extensive central necrosis. Microscopically, it consisted of spindle and epithelioid cells. Immunohistochemically, the cells stained positive for CD34, which is diagnostic of GIST.

Laminectomy-induced arachnoradiculitis: a postoperative serial MRI study.

Time-related changes of laminectomy-induced cauda equina adhesions were investigated by MRI in ten patients with degenerative spinal disease who underwent posterior surgery to the lumbar spine; seven had disc herniations and three spinal stenosis. Axial MRI was performed before and 3, 7, 21 and 42 days after surgery. Cauda equina adhesions were most severe at the laminectomised levels L3-4, L4-5 and L5-S1 (n = 16); partial adhesions were found in 9 of 16 levels at 6 weeks after surgery. At the L3-4 or L5-S1 levels (n = 14), the area of laminar exposure without laminectomy, the cauda equina adhesions continued 1 week after surgery, but thereafter resolved; only partial adhesions were seen at 5 of 14 levels 6 weeks after surgery. Shrinkage of the arachnoid sac was also found at the level of the laminectomy, but it re-expanded 3 weeks after surgery in all cases. Cauda equina adhesions and shrinkage of the sac were correlated closely with laminectomy, with or without discectomy, suggesting that an inflammatory process of deep wound healing may be involved in the mechanism of a laminectomy-induced arachnoradiculitis which may be correlated with post-operative leg symptoms.

Elevation of ratio of urinary N-acetylneuraminlactose to free sialic acid in some advanced cancer patients.

We estimated the levels of free sialic acid and sialylated oligosaccharides excreted in the urine of normal donors (n = 10) and patients with gastric cancer (n = 6) and colorectal cancer (n = 4). The total sialic acid level in cancer patients was similar to that in normal donors. However, the ratios of glycosidically bound sialic acids to free sialic acid were higher in some advanced cancer patients than in the normal donors. A major component of sialylated oligosaccharides was N-acetylneuraminyl alpha (2-->3) lactose. The elevation of the urinary ratio of this sialylated oligosaccharide to free sialic acid observed in some advanced cancer patients in this study may reflect the elevation of sialyltransferase activity in tumor tissues.

Effect of ionic and nonionic contrast media on regional distribution of thallium-201 in rabbits.

Cardiac output is effectively redistributed to each part of the body by regional changes in vascular resistance. Thallium-201 distribution reflects the fractional distribution of cardiac output and parallels regional blood flow. The side effects of iodinated contrast media in different organs have been well documented in animal experiments and clinical studies. However, no simultaneous assessment of regional blood flow change in each part of the body after the administration of contrast media has been reported. Using a double-dose thallium-201 method, we investigated the effect of contrast media on the regional distribution of thallium-201 in each organ as an estimate of regional blood flow change in rabbits. The distribution of 201T1 and 99mTc-MAA was similar in the heart, spleen, kidneys, and leg muscles in the control animals (r = 0.99). The regional distribution of thallium-201 significantly increased in the heart and leg muscle, but decreased in the liver in the nonionic (Iohexol) and ionic (Iothalamate) contrast medium groups as compared with the control group. There were no significant changes in the kidneys or intestine in these three groups in our study. The intravenous infusion of contrast media in rabbits causes uneven redistribution of regional blood flow in the heart, leg muscle and liver. These changes are more prominent in the ionic contrast medium group.

Clinical utility of three-dimensional time-of-flight magnetic resonance angiography for the evaluation of intracranial aneurysms.

Magnetic resonance (MR) angiographic studies of 14 patients with intracranial aneurysms (AN) were analyzed retrospectively as compared with contrast angiographic studies. Eighteen of 19 (95%) lesions were detected, and the relation between AN and their parent vessels was precisely assessed. The diameter of the smallest aneurysm detected in our case was 3 mm. However, small vessels around AN were not visualized. Therefore, MR angiography (MRA) is definitely not a substitute for preoperative contrast angiography. MRA is a useful screening tool for nonruptured AN, but further refinement is required to evaluate emergency ruptured AN.

Basilar artery migraine. Reversible ischemia demonstrated by Tc-99m HMPAO brain SPECT.

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.

Distribution of 111In- and 125I-labeled monoclonal antibody 17-1A in mice bearing xenografts of human pancreatic carcinoma HuP-T4.

BACKGROUND: The prognosis of pancreatic adenocarcinoma still remains poor because of the lack of reliable diagnostic tests for early stages of the disease. Monoclonal antibody 17-1A (MoAb 17-1A) has been studied extensively, and the antigen recognized by MoAb 17-1A is expressed by adenocarcinomas of the pancreas and stomach, as well as other normal and malignant epithelial tissues. The potential of MoAb 17-1A was investigated for its ability to detect pancreatic carcinomas. The use of MoAb 17-1A in treatment also was studied. METHODS: Immunoreactivity of MoAb 17-1A with human pancreatic carcinoma cell line HuP-T4 was examined histochemically by the avidin-biotinylated enzyme complex method. MoAb 17-1A was labeled with 125I by the Iodogen method and 111In using either diethylenetriaminepentaacetic anhydride (cDTPA) or 1-(p-benzyldiazonium) diethylenetriaminepentaacetic acid (aDTPA). After injection in nude mice bearing HuP-T4 xenografts, the biodistribution of 111In- and 125I-labeled MoAb 17-1A was examined at various time points. RESULTS: Positive staining of MoAb 17-1A was noted for HuP-T4 cells. A statistically significant (P < 0.01) greater tumor uptake was observed at 3 days after intravenous injection of 125I-labeled MoAb 17-1A when compared with 125I-labeled nonspecific immunoglobulin G. 125I- and 111In-labeled MoAb 17-1A was concentrated in HuP-T4 carcinoma 1.9-4.8 times higher than in the spleen, heart, liver, and pancreas. CONCLUSIONS: MoAb 17-1A was found to bind selectively to human pancreatic carcinoma HuP-T4. Tumor exhibited higher uptake of radiolabeled MoAb 17-1A compared with adjacent normal tissues. These results suggest that MoAb 17-1A may be applicable to the radioimmunodetection and radioimmunotherapy of pancreatic adenocarcinomas.

[MR evaluation of common femoral arterial flow: age-related changes and characteristics in obstructive arterial disease of lower extremities].

Flow velocity measurements of the common femoral arteries in 60 lower extremities of 30 healthy subjects and 12 lower extremities of 7 patients with arteriosclerosis obliterans (ASO) were performed by means of magnetic resonance imaging with a use of presaturation bolus tracking (PBT) method. Our PBT method can provide both precise determination of flow velocity and evaluation of flow patterns within 30 minutes in the clinical setting. In phantom study, MR flow velocity had good correlation with actual flow velocity (r = 0.997). 30 healthy volunteers were classified into three groups; group I (20-40 years), group II (41-60 years) and group III (61-80 years). Starting time of acceleration (STA) were shortened as the age progressed. Peak reverse velocity (PRV), maximum deceleration rate (MDR), peak forward velocity/mean velocity ratio (PFV/MV) and pulsatility index (PI) were significantly decreased in group III as compared to group I and group II. Although intraluminal flow profile showed almost uniform during acceleration time on MR images, flow profile became disproportioned and reverse flow was observed in the medial portion during deceleration time. These characteristic hemodynamics were recognized in all healthy subjects regardless to the different age group. In ASO, STA was prolonged and PFV, PRV, Maximum acceleration rate, MDR, PFV/MV, PI, Vascular sectional area, flow volume were significantly decreased (p < 0.001) as compared to the control healthy group III. As the result we obtained marked characteristics such as flattening of curves and disappearance of reverse flow in MR flow waveform. On MR images, disproportion of intraluminal flow profile, decreased flow velocities during acceleration time and disappearance of reverse flow (11 of 12 extremities) during deceleration time were observed.

Colloid liver SPECT of hepatic alveolar echinococcosis.

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.

Regional distribution of 201Tl during one-leg exercise: comparison with leg blood flow by plethysmography.

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.

Long-term efficacy of heparin exercise treatment for patients with chronic effort angina: evaluation by exercise Tl-201 myocardial scintigraphy.

To determine the effects of heparin exercise treatment on the coronary collateral flow reserve, exercise thallium-201 myocardial perfusion images were obtained with the same work-load before and late after heparin exercise treatment (17 +/- 2 months, mean +/- S.E.). In six patients with stable effort angina, to develop the collateral circulation, treadmill exercise was performed 20 times for 2-3 weeks with pretreatment with a single intravenous dose of heparin (5000 IU). The coronary collateral flow reserve was measured quantitatively as a severity score by analysis of exercise thallium-201 myocardial perfusion images. The severity score was decreased from 11,976 +/- 1722 to 5531 +/- 1967 (P < 0.05) long after heparin exercise treatment. The ST segment depression at the time of peak exercise was also decreased from 0.15 +/- 0.02 mV to 0.05 +/- 0.02 mV. In an additional five medically treated patients, these indexes remained unchanged during 18 +/- 3 months of follow-up period. These findings demonstrate that the coronary collateral flow reserve is significantly enhanced with heparin exercise treatment. These preliminary results lend support for heparin exercise treatment as one of the possible therapeutic modalities for treating patients with chronic stable effort angina.

Simultaneous measurements of twenty-four-hour whole-body retention of 47Ca-chloride and 99mTc-MDP: early differentiation of metabolic bone diseases in rat models.

The 24-h whole-body retention (24-h WBR) of 47Ca-chloride and 99mTc-MDP was measured in four rat models over a 6-week period at 2 week intervals. Fine detail bone radiographs of the femurs and histologic bone specimens were also obtained simultaneously. In the osteomalacic (M) and steroid-induced osteoporotic (S) groups the 24-h WBR values of 47Ca were significantly lower, and in the osteoporotic (P) group were higher than in the control (C) group from the second week. The 24-h WBR values of 99mTc-MDP were significantly higher in the M group and were lower in the S group from the second week. Simultaneous measurements of 24-h WBR of these two radiopharmaceuticals facilitated the early differentiation of metabolic bone diseases in the animal models prior to the detection of radiologic bone changes.

Biodistribution of intravenously injected [131I]Lipiodol in rats.

Tissue distribution studies of intravenously injected [131I]Lipiodol in rats were performed, and serial whole-body autoradiograms were obtained simultaneously for seven days. Most of the radiotracer was retained in the lungs. Lung uptake reached a maximum (42.44% ID/g) at 1 day, with an effective half-life of 3.0 days. The other organs showed markedly lower uptakes (less than 0.56% ID/g). The ratio between liver and lung reached a maximum (0.01) at 3 hr and then decreased with time, precluding adequate external imaging of the liver as compared with the lung.

Effect of diets containing different levels of calcium, phosphate, and vitamin D3 on tooth uptake of 47Ca-chloride in rat models: comparison with bone uptake.

The effect of dietary manipulation on global tooth uptake of 47Ca-chloride was evaluated in three rat models of metabolic bone diseases verified by histologic bone study. The 24-hr tooth uptake of 47Ca-chloride was significantly decreased in the osteomalacic group, and was increased in the osteoporotic group at the fourth week. Tooth uptake closely paralleled femoral uptake at a correlation coefficient of 0.73 (p less than 0.01). The uptake of 47Ca-chloride in tooth was found to be more affected by dietary manipulation than that in femur in our rat models.

[Magnetic resonance imaging: evaluation of the Blalock-Taussig shunts and anatomy of the pulmonary artery].

The morphology and circulation of the pulmonary arteries and shunt vessels were evaluated by magnetic resonance imaging (MRI) in 8 patients with cyanotic heart disease after a Blalock-Taussig shunt operation. Their ages ranged from one month to 17 years. MRI permitted assessment of the size and patency of the Blalock-Taussig shunts, as well as the size and morphology of the pulmonary arteries in all patients. Measurements of the vessel diameters on MRI correlated well with the angiographic measurements (main pulmonary artery, r = 0.98; right pulmonary artery, r = 0.98; left pulmonary artery, r = 0.98; and Blalock-Taussig shunt, r = 0.97). MRI successfully imaged 3 of 4 shunt obstructions and 3 of 4 pulmonary stenoses with high resolution. In assessing peripheral pulmonary stenosis or obstruction, MRI was superior to echocardiography, the latter being unable to image peripheral pulmonary arteries satisfactorily. We concluded that MRI is an excellent noninvasive method for serially evaluating the anatomy and function of Blalock-Taussig shunts and pulmonary arteries, which is particularly useful for children with cyanotic congenital heart disease.

A case of liver echinococcosis mimicing a solid liver tumor.

A case of hepatic echinococcosis mimicing a solid tumor was presented. The echinococcosis appeared as an echogenic mass in US, a low density area in CT, and an area of low (T1-weighted image) and high (T2-weighted image) intensity in MRI. Echo-guided biopsy showed PAS-positive cuticle layer of echinococcus in the necrotic tissue. Anular features around the lesion noted in MRI seemed to imply increased hepatic tissue water (congestion and/or edema). When a solid tumor is noted in the liver, proper history taking and awareness of this disease will decrease the chance of misdiagnosis.