Novel LPL mutation (L303F) found in a patient associated with coronary artery disease and severe systemic atherosclerosis.

BACKGROUND: Patients with lipoprotein lipase (LPL) deficiency had been generally thought to be spared accelerated atherosclerosis in spite of a marked elevation of plasma triglyceride levels. However, it has been recently reported that some heterozygous and homozygous LPL-deficient patients are associated with premature atherosclerosis. In this paper, we report a 55-year-old type I hyperlipidaemic patient with a novel missense mutation in the LPL gene. PATIENT AND RESULTS: The patient had suffered from coronary artery disease, abdominal aortic aneurysm, and stenoses of the bilateral renal arteries and superficial femoral arteries. Sequencing of the genomic DNA revealed that the patient was a homozygote for the mutation, a G to C transition at nucleotide position 1069 in the exon 6, resulting in an amino acid substitution of Phe for Leu303 (L303F). Approximately 6% and approximately 40% of normal LPL activity and LPL mass, respectively, were detected in the patient's postheparin plasma. An in vitro expression study demonstrated that COS7 cells transfected with L303F mutant cDNA produced a 40% amount of LPL protein in cell lysates compared with normal cDNA, but no protein was detected in the media. Lipoprotein lipase activity was completely absent in both lysates and media of the cells transfected with the mutant cDNA, suggesting that this mutation in the LPL gene results in the production of a functionally inactive protein. CONCLUSION: This case suggests that the LPL missense mutation (L303F), which impairs lipolysis but preserves the LPL mass, is proatherogenic.

Reference values of plasma lipoprotein (a) in newly classified apolipoprotein(a) phenotype groups in the Japanese population.

We tried to establish the reference values of plasma lipoprotein (a) [Lp(a)] concentration in phenotype groups of apoliprotein(a) [apo A] classified by a new criterion. Lp(a) concentration was determined by latex agglutination immunoassay, and apo A was analysed by electrophoresis in sodium dodecyl sulphate-polyacrylamide gel and a Western blotting technique. According to the relative mobility to the apo B-100 band, apo A was classified into 11 isoforms, i.e. F, B, and S1-S9, and the phenotype was defined by their apparent combination. The frequency ratio of single-band versus double-band was approximately 2:1. In 382 cases of single-band, the most frequent phenotype was S5 (24.3%), followed by S4 (17.3%), S6 (15.4%) and S3 (14.4%). In 181 cases of double-band, S5/S6 phenotype was observed most frequently (12.2%). followed by S4/S5 (10.5%) and S3/S6 (7.2%). The reference value was determined between antilogs of the mean +/- 1.96 standard deviation by logarithmic transformation of all observed values for individual phenotype cases. These results suggest that the reference values shown to be variable with apo A phenotypes should be useful for evaluating Lp(a) values in diagnosis of atherosclerosis.

Use of iodine-123 metaiodobenzylguanidine scintigraphy to assess cardiac sympathetic denervation and the impact of hypertension in patients with non-insulin-dependent diabetes mellitus.

The objectives of this clinical study using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy were (a) to evaluate cardiac sympathetic denervation in non-insulin-dependent diabetes mellitus (NIDDM) patients with and without hypertension and (b) to investigate the relation between cardiac sympathetic denervation and prognosis in NIDDM patients. We compared clinical characteristics and MIBG data [heart to mediastinum (H/M) ratio and % washout rate (WR)] in a control group and NIDDM patients with and without hypertension. MIBG scintigraphy was performed in 11 controls and 82 NIDDM patients without overt cardiovascular disease except for hypertension (systolic blood pressure >/=140 and/or diastolic blood pressure >/=90 mmHg). After MIBG examination, blood pressure was measured regularly in all NIDDM patients. There were significant differences between 65 normotensive and 17 hypertensive NIDDM patients with respect to age (55+/-11 vs 63+/-12 years, respectively, P<0.05), prevalence of diabetic retinopathy (12% vs 35%, respectively, P<0.05) and systolic blood pressure (120+/-12 vs 145+/-16 mmHg, respectively, P<0.001). The H/M ratio in hypertensive NIDDM patients was significantly lower than in the control group (1. 81+/-0.29 vs 2.27+/-0.20, respectively, P<0.01). During the follow-up period (18+/- 12 months), 17 NIDDM patients newly developed hypertension after MIBG examination. There were no significant differences in their clinical characteristics compared with persistently normotensive or hypertensive NIDDM patients. %WR in patients with new onset hypertension was significantly higher than in the control group (30.88%+/-16.87% vs 12.89%+/-11.94%, respectively, P<0.05). Moreover, in these patients %WR correlated with duration from the date of MIBG scintigraphy to the onset of hypertension (r=-0.512, P<0.05). Five NIDDM patients died during the follow-up period (four newly hypertensive patients and one normotensive patient). There were significant statistical differences between the control group and non-survivors in terms of age (54+/-11 vs 73+/-11 years, respectively, P<0.01), H/M ratio (2. 27+/- 0.20 vs 1.64+/-0.36, respectively, P<0.01) and %WR (12. 89%+/-11.94% vs 42.52%+/-22.39%, respectively, P<0.01). In conclusion, cardiac sympathetic denervation using MIBG scintigraphy observed in hypertensive NIDDM patients, and was more profound in non-survivors. MIBG scintigraphy proved useful for the evaluation of NIDDM patients with new onset hypertension, and it was found that NIDDM patients with abnormalities on MIBG scintigraphy needed to be observe carefully.

[Plasma nicotinic acid levels in hemodialysis patients after the administration of niceritrol].

Lp(a) has recently begun to attract attention as a risk factor of atherosclerotic disease, especially of ischemic heart disease. The Lp(a) concentration in the serum was shown to be important for chronic hemodialysis patients who have high mortality due to cardiovascular disease. Nicotinic acid derivatives, which are recognized for their capacity to lower the serum Lp(a) concentration, are effective against a high Lp(a) concentration in hemodialysis patients. In this study, niceritrol which is a nicotinic acid derivative was tested on hemodialysis patients and healthy controls by investigating the serum nicotinic acid level. Serum nicotinic acid concentration was also measured by the severity of renal dysfunction of patients untreated by niceritrol. The blood nicotinic acid concentration in healthy controls (n = 4) was changed after 2 hrs by the administration of niceritrol from 9.8 +/- 1.4 ng/ml to 192.7 +/- 23.1 ng/ml then slowly decreased. Chronic hemodialysis patients who take niceritrol every day showed the highest nicotinic acid serum concentration (500-1,000 ng/ml) on the day without hemodialysis and the serum level decreased with dialysis for 4 hrs to 25-80%. There was no significant difference in the nicotinic acid level in the serum between healthy controls (n = 10), chronic glomerulonephritis patients (n = 7), chronic renal failure patients (n = 8) and chronic hemodialysis patients (n = 17). Lp(a) concentration in the serum, however, was increased with greater severity of renal dysfunction, The side effect was not observed in any cases administered niceritrol. These data suggest nicotinate derivatives are effective for hemodialysis patients. High nicotinic acid level in the serum after treatment with niceritrol was lowered by dialysis. It is plausible that the nicotinate level in patients without niceritrol treatment did not influence the Lp(a) concentration, because there was no increase in the nicotinate level of the serum even if the patients had renal dysfunction.

Effect of vitamin E on lipid metabolism and atherosclerosis in ESRD patients.

BACKGROUND: Oxidative stress is enhanced in patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD). Bioincompatibility represents an important source of reactive oxygen species. HD patients exhibit altered anti-oxidative defences and anti-oxidative vitamins such as vitamin E and C are altered in uremia. Frequently, HD patients also suffer from atherosclerotic cardiac disease. We have previously reported that low density lipoprotein (LDL) of HD patients is rich in malondialdehyde (MDA), an end product of lipid peroxidation. MDA rich LDL is thought to be an atherogenic lipoprotein due to its enhancement of macrophage foam cell formation. METHODS: We conducted a controlled study for two years comparing the effects of a vitamin E coated cellulose membrane dialyzer and an ordinary cellulose membrane dialyzer on lipid metabolism and the progress of atherosclerosis. LDL-MDA and oxidized LDL (ox-LDL) were measured in HD patients using these two types of dialyzers. Plasma vitamin E and lipid concentrations were also evaluated. The aortic calcification index (ACI) was evaluated by CT scan to assess the progress of atherosclerosis before and for every year after treatment. RESULTS: Use of a vitamin E coated cellulose membrane dialyzer for six months, one year and two years resulted in a significant reduction in LDL-MDA and ox-LDL compared to the ordinary cellulose membrane dialyzer. Treatment with a vitamin E-coated dialyzer significantly reduced the percentage increase in ACI after 24 months compared to the control. There were no significant changes in plasma vitamin E and lipid concentrations between the two groups. CONCLUSIONS: These results suggest that the oxidative stress could be one of the stimulating factors of abnormal lipid metabolism and atherosclerosis in ESRD patients.

Factors associated with calcification of the abdominal aorta in hemodialysis patients.

BACKGROUND: Cardiovascular and cerebrovascular injury caused by arteriosclerosis has been the major cause of the death in hemodialysis (HD) patients. We quantitatively analyzed and evaluated the severity of abdominal aortic calcification in HD patients in comparison to risk factors for arteriosclerosis. METHODS: One hundred thirty-seven HD patients were examined. Using image analysis software, areas of the calcified abdominal aorta were quantitatively analyzed on plain computerized tomography images. Other factors such as blood pressure (BP), lipid levels, and calcium (Ca) x phosphorus (Pi) value were also analyzed. RESULTS: Patients with a higher one-year average of systolic BP showed a higher severity of abdominal aortic calcification. That is, the severity of abdominal aortic calcification in patients with a one-year systolic BP average above 160 mm Hg was 31.5 +/- 13.6%, and this severity was significantly higher than that in patients with a one-year systolic BP average of less than 120 mm Hg (8.0 +/- 7.7%, P < 0.01). The severity of abdominal aortic calcification in patients demonstrating risk values of ectopic calcification, that is serum Ca x Pi > or = 60 (mg/dl), on more than 4 of 24 measurements within one year (25.8 +/- 13.6%) was significantly higher than the severity of aortic calcification in patients demonstrating this value less than four times in one year (P < 0.05). There was no correlation between levels of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, lipoprotein(a), and severity of abdominal aortic calcification. CONCLUSIONS: Systolic BP levels and the product of serum Ca and Pi were related to the severity of abdominal aortic calcification in HD patients. These observations suggested that BP control, as well as control of serum Ca and Pi levels, was important in preventing the progression of abdominal aortic arteriosclerosis.

[Quantitative assessment of 201Tl-SPECT in tumors of bone and soft tissue].

201Tl-SPECT was performed to diagnose the malignancy of bone and soft tissue tumors by visual and quantitative assessment in 48 patients (17 malignant lesions and 31 benign lesions). SPECT images were obtained in the early phase (15 min after injection) and the delayed phase (240 min). By visual assessment a tumor was considered malignant if high accumulation was found in the tumor in the early phase and the accumulation was confirmed in the delayed phase. Tumors which did not meet these criteria were considered benign. For quantitative assessment, the ROI (region of interest) accumulation ratios of the tumor to the contralateral normal tissue in the early phase (ER) and in the delayed phase (DR), the ROI accumulation ratio of the delayed phase to the early phase of the tumor (Td/Te), and the ROI accumulation ratio of the delayed phase to the early phase of the contralateral normal tissue (Nd/Ne) were obtained. Sixteen patients with malignant tumors each had a high accumulation each but 12 of 31 benign lesions had no high accumulation on visual assessment. Furthermore, the accuracy was 85.4%, sensitivity 94.1%, and specificity 80.6%. Quantitative assessment was performed for 36 cases of high accumulation. The ER of malignant and benign lesions was 5.51 +/- 3.73 and 2.75 +/- 2.17, respectively, and the ER of malignant lesions was significantly higher than that of benign lesions. The DR did not demonstrate a significant difference. If the tumor having an ER greater than 3.9 was assumed to be malignant, the accuracy for differentiating malignant lesions from benign lesions was 85.4%. The Td/Te of benign lesions (0.97 +/- 0.28) was higher than that of malignant lesions (0.77 +/- 0.09). The Nd/Ne of normal tissue which contained muscles in both lesions were higher than 1.4. In conclusion, 201Tl-SPECT was very useful for the differential diagnosis of benign or malignant bone and soft tissue tumors. The ER was important for quantitative assessment, but a delayed image was necessary for visual assessment.

Effects of aldose reductase inhibitor and vitamin B12 on myocardial uptake of iodine-123 metaiodobenzylguanidine in patients with non-insulin-dependent diabetes mellitus.

This study was undertaken to examine the effects of aldose reductase inhibitor (ARI) and vitamin B12 (VB12) on myocardial uptake of iodine-123 metaiodobenzylguanidine (MIBG) in patients with diabetic autonomic disorder. Myocardial scintigraphy using 123I-MIBG was performed on 20 healthy volunteers (controls) and 56 patients with non-insulin-dependent diabetes mellitus (NIDDM), in order to obtain the heart/mediastinum ratio in the initial (HMi) and the delayed images (HMd), and the washout rate (%WR). Thirty-four of the 56 NIDDM patients could be diagnosed as having diabetic autonomic disorder by evaluating their scintigraphic findings in comparison with the controls. Seventeen of these 34 patients received 150 mg/day of doses before meals, and the other 17 received 1.5 mg/day of mecobalamin (VB12 group) in three divided doses after meals, for 3-5 months. According to the presence or absence of clinical symptoms of autonomic or peripheral somatic nerve disorder, the patients were subclassified into four groups. group 1=patients, with autonomic symptoms or somatosensory disorder in the ARI group; group 2=patients without autonomic symptoms or somatosensory disorder in the ARI group; group 3=patients with autonomic symptoms or somatosensory disorder in the VB12 group; and group 4=patients without autonomic symptoms or somatosensory disorder in the VB12 group. After completion of the treatment, myocardial scintigraphy was performed again. Comparing the results obtained before and after the treatment, it was seen that ARI improved only the HMi in group 1 (P=0.046), whereas VB12 significantly improved HMi in the group 3 (P=0.018) and HMi, HMd and %WR in group 4 (P=0.043, P=0.018 and P=0.043, respectively). We conclude that VB12 is more efficacious than ARI in the treatment of diabetic cardiovascular autonomic disorder.

Malignant lymphoma originating in the jejunum of a long-term follow-up case of protein-losing enteropathy.

A 50-year-old female patient, who had been followed for 15 years for protein-losing enteropathy, was hospitalized due to epigastric pain. Examination on admission revealed that the patient was in the sub-ileus state. On the 26th day after admission, she complained of severe abdominal pain and shortly after she went into shock. The emergency laparotomy documented intestinal perforation and a tumor. The perforated site was right at the middle of tumor. The histological and histochemical studies identified the tumor as malignant lymphoma of B lymphocyte lineage. As far as we know, this is the third case of malignant lymphoma occurring in the jejunum in a patient with protein-losing enteropathy in Japan. The possible relationship between lymphomas and protein-losing enteropathy is discussed.

[Three-dimensional helical CT angiography of the abdomen].

To evaluate the quality of three-dimensional (3D) images of the abdominal vasculature acquired using enhanced helical CT, 3D reconstructions were performed for 43 examinations (38 patients). Twenty-one of 43 examinations were also reconstructed by Maximum Intensity Projection (MIP). The CT scanner employed was the Toshiba Xforce. Helical CT data were acquired using up to 20 continuous 1.5-sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 to 10 mm/1.5 sec. Axial images were reconstructed at a section interval of 2 mm. Optimal protocol on enhanced helical CT was as follows: Iopamidol 300 mg I/ml was administered intravenously using a biphasic technique (3-4 ml/sec for the initial 100 ml, followed by 0.7-1.5 ml for the remaining 50 ml), and delay times of the early and late phases were 25-35 and 90 sec, respectively. Aortic branches were clearly demonstrated on early phase, while portal branches were well defined on late phase. In the visualization of abdominal vessels, 3D images were nearly equal to MIP images. However, for anteroposterior images, MIP images were superior to 3D images in quality, because 3D images had some longitudinal direction artifacts. Three-dimensional images were considered to be useful for correctly evaluating overlapping abdominal vasculatures. From the above results, 3D and MIP images of the abdominal vasculature obtained using enhanced helical CT were considered to compensate for each other.

Three-dimensional display of pulmonary nodules using helical CT.

To evaluate the clinical usefulness of three-dimensional (3D) images of pulmonary nodules acquired using helical CT, 3D reconstructions were performed in 32 patients using a CEMAX VIPstation. The CT scanner employed was the Toshiba Xforce. Helical CT data were acquired using up to 20 continuous 1.5-sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 mm/1.5 sec. Axial images were reconstructed at a section interval of 2 mm. The optimal lower and upper threshold CT values for 3D images were as follows: 1) solid pulmonary nodule (-700--400/-100 HU), 2) tumor invading pleura or chest wall (-700--400/-200 HU), 3) pulmonary nodule with cavity (-700--400/50 HU), 4) small pulmonary nodule (< 10 mm) (-750--650/-100 HU), and 5) arteriovenous malformation (180/500 HU). In all cases, it was possible not only to demonstrate abnormal findings three-dimensionally but also to grasp anatomical relationships among the pulmonary nodule, bronchi, vessels, and chest wall.

Blueberry juice: preliminary evaluation as an oral contrast agent in gastrointestinal MR imaging.

PURPOSE: To evaluate the use of blueberry juice as an oral contrast agent in magnetic resonance (MR) imaging. MATERIALS AND METHODS: MR imaging of phantoms of blueberry juice and of manganese chloride solutions with different manganese concentrations were conducted. Patient trials were conducted to evaluate manganese blood levels and signal intensity changes on MR images of the abdomen. T1- and T2-weighted conventional spin-echo MR imaging was performed at various field strengths. Six radiologists graded image contrast; signal intensities were calculated. RESULTS: T1 and T2 relaxation curves for blueberry juice and manganese chloride showed similar signal intensity profiles as a function of manganese concentration. Blood concentrations of manganese were unchanged before and after an oral dose of blueberry juice that contained 18 mg of manganese. The results of patient studies indicated that the optimal oral dose of manganese in blueberry juice was 3-4 mg/dL. T1 and T2 shortening were apparent at field strengths of 0.2-1.5 T. CONCLUSION: At appropriate concentrations, blueberry juice has the potential to be an effective oral contrast agent for MR imaging.

[Assessment of myocardial contraction and relaxation with 99mTc-tetrofosmin multi-gated myocardial SPECT].

Myocardial relaxation at the diastolic phase was not evaluated by multi-gated myocardial SPECT, although myocardial contraction at the systolic phase was studied by percent wall thickening and Bull's eye methods. We make out a myocardial volume curve and report to evaluate the myocardial relaxation using multi-gated myocardial SPECT. The study population consisted of 3 normal human subjects (3 male, 32-37 years old), 10 idiopathic cardiomyopathy, 10 coronary artery disease and 1 hypertensive heart disease combined with aortic regurgitation. All cases were injected 555 MBq of 99mTc-tetrofosmin (Amersham Healthcare Corporation) intravenously at rest. A triple detector gamma-camera (GCA-9300A, Toshiba Medical, Japan) and a data processing computer (GMS-5500A, Toshiba Medical, Japan) were used in this study. A cardiac cycle (R-R interval) was divided by 16 frames (50-80 msec per 1 frame). Eight myocardial volume curves were calculated at the anterior wall, apex and inferior wall of the vertical long axis view and were calculated at the septal wall, apex and lateral wall of the horizontal long axis view, respectively. The patterns of the myocardial volume curves were classified into 5 patterns (Normal pattern (N), Delayed Contraction pattern (DC), Delayed Relaxation pattern (DR), Mixed pattern (M) and Normal pattern with Decreased amplitude (ND)). Myocardial uptake was evaluated visually of grading into severe hypertrophy (5), hypertrophy (4), normal (3), mild hypoperfusion (2), hypoperfusion (1) and perfusion defect (0). We compared patterns of the myocardial volume curves to myocardial uptake in the same segments. It was possible to detect myocardial edge of the total 16 frames with 50-60% threshold in the normal volunteer and in patients with hypertrophic cardiomyopathy and to make a myocardial volume curve. The region of the severe myocardial perfusion defect could be detected with 20% threshold in patients with old myocardial infarction. In comparison with myocardial volume curves and myocardial uptake, 74.6% in the N pattern had a normal uptake (3), 66.7% in the ND pattern had a normal uptake (3), 61.5% in the DC pattern had a hypoperfusion segment (0, 1 or fill-in to normal uptake), 44.4% in the DR pattern had a hypertrophic segment (4, 5 or fill-in to increased uptake). The pattern of myocardial volume curve indicates myocardial contractility and relaxation in each myocardial segment.

Thrombocytopenia associated with platelet-associated immunoglobulin G in alcoholic hepatitis.

A 45 year old Japanese man with alcoholic hepatitis developed thrombocytopenia together with an increase in the level of platelet-associated immunoglobulin G (PAIgG). Bone marrow aspiration revealed a normal nucleated cell count and a slight increase of megakaryocytes. After abstinence from alcohol, laboratory and symptomatic improvement occurred in association with a prompt increase in the platelet count and a corresponding decrease of PAIgG. These findings suggest that PAIgG may have been involved in the development of thrombocytopenia in this patient.

[Clinical evaluation of asymmetric film-screen system for thoracic lesions].

We investigated the clinical usefulness of the asymmetric film-screen system on postero-anterior chest roentgenograms for thoracic lesions. The asymmetric film-screen system, the so-called Kodak Insight thoracic imaging system, records a different image on each side of double-emulsion film. An image displaying the lung field is captured on the anterior side of the film, while one displaying the mediastinal, retrocardiac and retrodiaphragmatic structures is captured on the posterior side. The clinical usefulness of the asymmetric film was evaluated in 20 patients for visibility of the anatomical structures and abnormal lesions in comparison with conventional film. In the asymmetric film-screen system, the front and rear screens were HC (high contrast) and Regular, respectively. Chest radiography was performed at 200mA and 100kVp. As conventional film, we used SRC film (Konica, orthotype film), and chest radiography was performed at 100mA and 130kVp. The chest roentgenograms obtained with the asymmetric film-screen system provided better information on normal structures and abnormal lesions in the lung field, but slightly inferior information on mediastinal structures. In conclusion, it was considered that the asymmetric film-screen system was useful for thoracic lesions.

[Contrast enhancement effect of new oral agent (blueberry juice) for upper abdominal MR imaging].

Manganese is known to affect relaxation times. Blueberry is naturally rich in manganese, and oral contrast effect by its squeezed juice (B. J) was expected. At some appropriate concentration of manganese within daily intake level, B. J worked as positive contrast agent on T1WIs and negative one on T2WIs simultaneously without any side effects. The negative effect on T2WIs could reduce ghost artifacts from motion of high intensity structures. B. J improved confirmation of gastroduodenal tract regardless of field strength and could be adapted for fast SE. We introduced a preliminary examination of B. J as an oral contrast agent for upper abdominal MRI.

[A case of malignant lymphoma of the thyroid accompanied by interstitial pneumonitis during radiation therapy after systemic chemotherapy].

We reported a case of malignant lymphoma of the thyroid accompanied by interstitial pneumonitis during radiation therapy after systemic chemotherapy. Thyroid malignant lymphoma is a rare malignant tumor, which usually responds well to irradiation and systemic chemotherapy. Interstitial pneumonitis occurred during radiation after systemic chemotherapy. In this case, irradiation was simultaneously done with the chemotherapy. The radiation field included the neck and upper mediastinum. Chest X-ray showed multiple patchy shadows in both the middle and lower lung field, and it changed to contraction shadows after steroid pulse therapy. 67Ga scintigram showed multifocal increase of uptake, when chest X-ray patchy shadows were seen only in the middle and lower lung fields. 67Ga scintigraphy and CT were considered useful for evaluation of drug-induced interstitial pneumonitis.

[A case of benign paraganglioma arising in the middle mediastinum; 201Tl-SPECT for differentiation from malignant tumor].

A case of benign paraganglioma arising in the middle mediastinum was reported. 201Tl SPECT showed high accumulation in tumor on early images at 15 min and reduced on late images at 3 hours after infusion. The patient was a 57 year old female. In the contrast enhanced CT, 3 x 4 cm tumor with intensive enhancement was recognized at the right middle mediastinum. Under the radiological images, the tumor was surgically removed. The pathologic diagnosis was a low atypical nonfunctioning aortico-pulmonary paraganglioma. This report was suggested that 201Tl SPECT was useful for differential diagnosis of benign neurogenic mediastinal neoplasms.

[A basic study of multi-gated single photon emission computed tomography with thallium-201].

A Multi-gated SPECT was acquired commonly in 64 x 64 matrix and 8 frames per cardiac cycle (64 x 64/8F). But it was not established that 64 x 64 matrix and 8 frames per cardiac cycle were the most suitable in multi-gated SPECT. Five normal volunteers were examined multi-gated 201Tl SPECT with 5 acquisition modes of 128 x 128 matrix/16 frames, 128 x 128/8F, 64 x 64/32F, 64 x 64/8F using multi-detector SPECT system (GCA-9300). And we calculated percent wall thickening (%WT) [%WT = (ES counts - ED counts)/ED counts] in 9 cases with 64 x 64/8F. The images quality of both 128 x 128/16F and 128 x 128/8F was not clear in compared with images of both 64 x 64/16F and 64 x 64/8F, because the end-diastolic phase of 128 x 128/16F images showed a decreased uptake of 201Tl in the antero-apical region. Although 64 x 64 (8) images had only 8 frames per cardiac cycle, we could observe systolic and diastolic phase and we could calculate %WT. The %WT (M +/- SD) of horizontal long axis images were 48 +/- 15 (sept. basal), 48 +/- 19 (sept. apical), 65 +/- 29 (apex), 49 +/- 22 (lat. apical) and 40 +/- 15 (lat. basal).(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical evaluation of two- and three-dimensional imaging of helical scanning CT in the upper abdomen].

To evaluate the usefulness of helical scanning CT of the upper abdomen, 30 patients with hepatic, adrenal, pancreatic and renal disease were examined using a Toshiba CT system, the Xforce. Helical scanning CT data were acquired using up to 20 continuous 1.5-second rotations, with a 1.5-3 ml bolus injection of contrast medium, and during a single breath-hold. Helical scanning provided both better data continuity and resolution than conventional scanning. The axial images with a slice thickness of 5 mm were not inferior in quality to equivalent images acquired by conventional CT, and multiplanar reconstruction images were superior. Targeted structures could be easily obtained because helical scanning CT permits image reconstruction in any direction. Using a CEMAX-VIPstation, we generated three-dimensional display images of high-density structures from the postcontrast data acquired with helical scanning. On these images, it was easy to observe the high-density tumors three-dimensionally and to determine the position of the tumors relative to the high-density surrounding organs. In conclusion, helical scanning CT was considered to be useful in clinical diagnosis involving the upper abdomen.