Depressed myocardial fatty acid metabolism in patients with muscular dystrophy.

Myocardial involvement is frequently associated with various types of muscular dystrophy and Thallium-201 scintigraphy can show regional myocardial perfusion abnormalities in patients with muscular dystrophy. Myocardial fatty acid metabolism can now be imaged using a radioiodinated branched fatty acid (123I-BMIPP). The present study evaluates myocardial fatty acid metabolism in muscular dystrophy. Twenty-eight patients underwent 123I-BMIPP(BMIPP) and Thallium dual single photon emission tomography. Regional uptake of both tracers was visually analyzed. We also assessed electrocardiography and echocardiography. The results showed that the BMIPP uptake compared to Thallium was smaller in 57% of all patients. BMIPP SPECT images revealed abnormalities in four of eight patients with a normal electrocardiogram. Abnormal BMIPP uptake with normal regional wall motion was evident in nine patients. The size of the region with defective BMIPP uptake was larger than that of asynergic areas detected by echocardiography in 11 patients. In conclusion, muscular dystrophy involves depressed myocardial fatty acid metabolism in larger extent of region than that in perfusion or mechanical abnormality.

Total and partial cardiac sympathetic denervation after surgical repair of ascending aortic aneurysm.

UNLABELLED: Sympathetic cardiopulmonary nerves arise from the cervical sympathetic trunks and travel alongside the great arteries to innervate the ventricles. Because of the proximity of the nerve and artery, cardiac sympathetic denervation may occur in patients who have just undergone surgery for the repair of an ascending aortic aneurysm. METHODS: To evaluate the cardiac sympathetic activity in aortic aneurysm, we performed cardiac 123I-metaiodobenzylguanidine (MIBG) imaging on 12 patients (mean age +/- SD, 47 +/- 17 y) before and after the surgical repair of an aneurysm. Seven patients scheduled for coronary artery bypass grafting also underwent 123I-MIBG imaging as controls for open-chest surgery. Planar images were obtained at 15 min (early) and 4 h (delayed) after injection of 111 MBq 123I-MIBG, and the cardiac 123I-MIBG uptake was graded quantitatively and visually. The quantitative evaluation was based on the heart-to-mediastinum ratio (H/M), and visual evaluation was performed by assigning a score of 0-3 (0 = absent, 1 = severely reduced, 2 = reduced, and 3 = normal). Heart rate variability using 24-h Holter electrocardiography was analyzed before and after the operation to generate a time-domain index of heart rate variability as an index of autonomic balance. RESULTS: In patients with aortic aneurysms, both early and delayed H/Ms were significantly decreased after the operation (early H/M: 1.84 +/- 0.16 before vs. 1.40 +/- 0.16 after, P = 0.001; delayed H/M: 1.79 +/- 0.38 before vs. 1.27 +/- 0.18 after, P = 0.004). Visual analysis of 123I-MIBG accumulation in early images showed absence of 123I-MIBG accumulation in 3 of 12 patients, a score of 1 in 7 patients, and a score of 2 in 2 patients. In contrast, no significant difference between H/M before surgery and H/M after surgery was seen in patients who underwent coronary artery bypass grafting. The time-domain index of heart rate variability was significantly lower after the operation than before (135 +/- 40 after vs. 96 +/- 27 before, P < 0.05). CONCLUSION: Cardiac sympathetic nerves are totally or partially denervated after the surgical repair of ascending aortic aneurysm.

Evaluation of myocardial perfusion and fatty acid uptake using a single injection of iodine-123-BMIPP in patients with acute coronary syndromes.

UNLABELLED: The purpose of this study was to clarify the possibility of simultaneous evaluation of myocardial perfusion and fatty acid metabolism using a single injection of 123I-beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) in patients with acute coronary syndromes. METHODS: Thirty patients with unstable angina pectoris (UAP group) and 15 patients with acute myocardial infarction (MI group) were studied. BMIPP dynamic SPECT was performed 2 min after the injection of BMIPP (185 MBq), and images were obtained every 3 min for 15 min with a three-head gamma camera. Conventional BMIPP SPECT was also performed 30 min after the injection. Serial BMIPP and resting 201TI images were compared. RESULTS: A 201TI-BMIPP mismatch between 30-min BMIPP and resting 201TI images was observed in 27 of 30 patients in the UAP group and 8 of 15 patients in the MI group, respectively. However, a 201TI-BMIPP mismatch between early (2-5-min) BMIPP and resting 201TI images was observed in only 2 of 30 patients in the UAP group and in only 2 of 15 patients in the MI group, respectively. The kappa statistics of tracer uptake between early BMIPP and resting 201TI images showed good concordance in UAP (kappa = 0.823) and MI (kappa = 0.765) groups, respectively. These results indicated that initial distribution of BMIPP reflects myocardial perfusion in patients with acute coronary syndromes. CONCLUSION: Myocardial perfusion and fatty acid metabolism can be evaluated simultaneously using a single injection of BMIPP, when images are taken soon (2-5 min) and long after the injection in patients with acute coronary syndromes.

A new view of the so-called adenoma malignum of the uterine cervix.

Adenoma malignum of the uterine cervix (mucinous type of minimal deviation adenocarcinoma, mucinous MDA), is a unique neoplasm that is difficult to diagnose owing to the deceptively benign appearance of the tumour cells. The present study was undertaken to explore the phenotypic expression of this tumour compared with those of non-neoplastic cervical tissues and of cervical carcinomas of various types. Ten cases of mucinous MDA, 50 cases with non-neoplastic cervical tissues, 13 of cervical adenocarcinoma including the mucinous (endocervical or intestinal type) and endometrioid types, and 2 of mucoepidermoid carcinoma were examined by various histochemical staining methods, including those for gastric mucins, pepsinogen, lysozyme, chromogranin A and carcinoembryonic antigen. The results revealed that mucinous MDA characteristically exhibited gastric phenotypes. The presence of gastric metaplasia was also demonstrated in 9 cases of mucinous MDA and in 5 of the other cases examined. The 7 endocervical-type adenocarcinomas also included 4 that expressed gastric phenotypes, and 2 of the 3 intestinal-type adenocarcinomas showed the same properties focally. These results indicate the presence of a group of lesions expressing gastric phenotypes in the uterine cervix and suggest a close relationship between these lesions. Cervical adenocarcinomas expressing gastric phenotypes are probably derived from MDA.

Helicobacter pylori infection produces reversible glycosylation changes to gastric mucins.

The protective ability of gastric mucins may depend largely on their oligosaccharide chains. We evaluated the effects of H. pylori infection on the glycosylation of gastric mucins. Gastric biopsy specimens from 20 H. pylori-infected patients before and after cure of the H. pylori infection and 8 normal uninfected volunteers were examined by immunostaining for simple mucin-type glycoproteins and blood-group-related antigens bearing type 1 chain backbone. The immunoreactivity in different gastric compartments was evaluated. Simple mucin-type glycoproteins and blood-group-related antigens were expressed in surface mucous cells. Simple mucin-type glycoproteins showed antrum-predominant expression in normal volunteers and were found in significantly fewer surface mucous cells in infected patients than in normal volunteers; their expression was restored after eradication of H. pylori. Sialyl Lewis(a) and Lewis(b) were expressed in fewer surface mucous cells after than before eradication. The patterns of glycosylation of gastric mucins vary in different gastric compartments and are reversibly altered by H. pylori infection. These alterations may affect the protective functions of gastric mucins.

Screening for unruptured asymptomatic intracranial aneurysms in patients undergoing coronary angiography.

In screening for unruptured asymptomatic intracranial aneurysms, an intracranial intra-arterial digital subtraction angiography (IA-DSA), posteroanterior view, was obtained in 72 consecutive patients who underwent coronary angiography for workup of angina pectoris. In cases where an aneurysm was suspected from IA-DSA, conventional intracranial angiography was obtained. Five asymptomatic unruptured aneurysms were detected in four of these cases. The aneurysms ranged from 4 to 16 mm in diameter. There were no complications associated with the coronary angiography nor with the additional intracranial IA-DSA, which required less than 5 minutes to perform in all cases. The value of performing intracranial IA-DSA in patients undergoing coronary angiography to screen for unruptured asymptomatic aneurysm is discussed, as is the possible racial differences in the frequency of aneurysms.

Spindle poisons induce allelic loss in mouse lymphoma cells through mitotic non-disjunction.

Aneuploidy is an important contributor to reproductive failure and tumor development. It arises spontaneously or as a result of exposure to aneugenic agents through non-disjunction. Two spindle poisons, colchicine (COL) and vinblastine (VBL) are mutagenic in the mouse lymphoma assay (MLA), a gene mutation assay that targets the heterozygous thymidine kinase (tk) gene on chromosome 11 in mouse lymphoma L5178Y tk+/- 3.7.2c cells. To investigate the mechanisms of spindle poison mutagenesis, we analyzed the COL- and VBL-induced TK mutants at the molecular and cytogenetic level. Loss of heterozygosity (LOH) analysis employing a microsatellite region within the tk locus revealed that almost all mutants had lost the functional tk allele. To determine the extent of the LOH, we further examined LOH mutants for heterozygosity at nine microsatellite loci spanning the entire chromosome 11. Interestingly, every microsatellite marker showed LOH in all COL- and VBL-induced LOH mutants, suggesting that these mutants were generated by loss of the whole chromosome 11 through mitotic non-disjunction. Chromosome painting analysis supported this hypothesis; there were no mutants showing structural changes such as deletions or translocations involving chromosome 11. In contrast, spontaneous TK mutants followed from point mutations, deletions and recombinational events as well as whole chromosome loss. Our present study indicates that spindle poisons induce mutations through mitotic non-disjunction without structural DNA changes and supports a possible mechanism in which a recessive mutation mediated by aneuploidy may develop tumors.

Enamel matrix derivative in the treatment of human intrabony osseous defects.

BACKGROUND: There is limited information available from clinical trials regarding the performance of enamel matrix derivative (EMD) in the treatment of periodontal intrabony defects. This randomized, double-blind, placebo-controlled, split-mouth study was designed to compare the clinical and radiographical effects of EMD treatment to that of placebo-controlled treatment for intrabony defects. METHODS: Sixteen patients were included, each of whom had 1 or 2 pairs of intrabony defects located contralaterally in the same arch. Thirty-six intrabony defects were randomly assigned treatment with flap surgery plus EMD or flap surgery plus placebo. At baseline and at the 12-month follow-up evaluation visit, clinical and radiographic measurements were determined. Data were statistically analyzed using the Wilcoxon-signed rank test (alpha = 0.05). RESULTS: At the 12-month visit, bleeding on probing for the EMD group was 0.11 +/- 0.32 compared to the placebo group, 0.61 +/- 0.50 (P <0.05). Probing depth reduction was greater in the EMD group (3.00 +/- 0.97 mm) compared to the placebo group (2.22 +/- 0.81 mm) (P <0.05). Mean values for clinical attachment gain in the EMD and the placebo groups were 1.72 +/- 1.07 mm and 0.83 +/- 0.86 mm, respectively (P <0.05). Vertical relative attachment gain was 38.5 +/- 22.6% in the EMD group and 21.4 +/- 25.2% in the placebo group (P<0.05). Radiographic bone density gain was greater in the EMD (20.2 +/- 16.6%) compared to the placebo group (-3.94 +/- 23.3%) (P<0.01). CONCLUSIONS: Treatment with flap surgery and EMD, compared to flap surgery with placebo, produced a significantly more favorable clinical improvement in intrabony periodontal defects.

Comparison of parameters of 123I-MIBG scintigraphy for predicting prognosis in patients with dilated cardiomyopathy.

123I-metaiodobenzylguanidine (MIBG) scintigraphy has been used to predict prognosis of patients with dilated cardiomyopathy (DCM), although it is unknown which parameter of MIBG is the most useful clinically. We studied MIBG in 59 patients with DCM, and followed them up to evaluate the prognosis of DCM. Single photon emission tomography (SPET) and planar imaging were performed, both early (e) and 4 h (delayed, d) post-injection. 201Tl (TL) SPET and radionuclide-ventriculography were also investigated. The total defect score of early and delayed MIBG and 201 Tl (MIBGeDS, MIBGdDS, TLDS) was analysed visually for each SPET image. The heart to mediastinum ratio (H/M) for both the early and delayed MIBG planar images and myocardial washout rate at 4 h were analysed quantitatively. Sixteen patients died during follow-up. Cox Hazards univariate analysis selected washout rate (P < 0.0001), H/Me (P = 0.0012), H/Md (P = 0.0001) and left ventricular ejection fraction (P = 0.0004) as indices for the prediction of cardiac death. Multivariate analysis selected washout rate as the most powerful independent predictor of prognosis (P < 0.0001). Survival curves with a threshold value of 52% for washout rate were able to differentiate a negative outcome from survival (P < 0.0001). TLDS, MIBGeDS and MIBGdDS were not useful in the prediction of prognosis. The washout rate of MIBG is the most potent predictor of cardiac death and is considered clinically useful.

Evaluation of regional cardiac sympathetic innervation in congenital long QT syndrome using 123I-MIBG scintigraphy.

The aim of this study was to determine whether sympathetic imbalance in congenital long QT syndrome (LQTS) can be identified by cardiac sympathetic neuronal dysinnervation. 123I-metaiodobenzylguanidine (MIBG) is a tracer of the norepinephrine analogue which reflects the regional innervation and norepinephrine kinetics in cardiac sympathetic nerves. Sixteen patients with LQTS, who were members of 12 families, and 7 normal controls underwent MIBG scintigraphy. Myocardial SPET and planar images were obtained 15 min and 4 h after the injection of MIBG in each patient. The relative regional uptake (RRU) and regional washout rate (rWR) of MIBG at 4 h in each of nine regions were compared with those in the control group. The heat-to-mediastinum ratio (H/M) and global washout rate (GWR) were also calculated. The RRU, rWR, H/M and GWR showed no significant difference between LQTS patients and normal controls. Furthermore, the RRU in 96% of all regions in LQTS was within the mean +/- 2 standard deviations of that in the control group. Patients with LQTS have normal cardiac sympathetic innervation, as assessed by MIBG. The sympathetic imbalance hypothesis is unlikely to be attributed to an abnormal distribution and different regional norepinephrine kinetics of cardiac sympathetic nerves.

Suppression of secondary hyperparathyroidism in chronic dialysis patients by single oral weekly dose of 1,25-dihydroxycholecalciferol.

Eleven hemodialysis patients who developed refractory secondary hyperparathyroidism, despite conventional vitamin D therapy, were treated with large oral doses of 1,25-dihydroxycholecalciferol [1,25(OH)2D3]. Therapeutic regimen was a single oral dose of up to 8.0 micrograms administered once weekly following hemodialysis. A maximum serum level of 1,25(OH)2D occurred four hours after the 8.0 micrograms dose. A positive correlation (Y = 84.3X-22.1: P < 0.01) was found between the maximal serum 1,25(OH)2D concentration (Cmax) and the dose of 1,25(OH)2D3 when plotted on a logarithmic scale. Forty-eight hours after the administration of the 8.0 micrograms dose, the parathyroid hormone (PTH) level and the alkaline phosphatase activity (ALP) were markedly decreased without evidence of hypercalcemia. A significant inverse relationship was found between the Cmax of 1,25(OH)2D and the percent change in the PTH level measured after 48 hours, either with carboxy-terminal (C-PTH) or the highly sensitive mid-portion assay (HS-PTH). From these results, the level of serum 1,25(OH)2D required to blunt the rise in serum PTH was 168 pg/ml and 203 pg/ml, respectively; these serum levels were achieved by the oral administration of doses of 6.0-8.0 micrograms or higher. There were no adverse effects of treatment. Following this study, one patient was continuously treated with 8.0 micrograms of 1,25(OH)2D3 orally once a week for 18 months. There was a therapeutic effect (as evidenced by PTH suppression, ALP suppression and the disappearance of subjective complaints) without the development of severe hypercalcemia or hyperphosphatemia. This treatment may help to prevent or treat secondary hyperparathyroidism in patients receiving long-term dialysis.

A case of amylase-producing lung cancer.

A case of lung cancer with hyperamylasemia was studied. Small cell carcinoma was diagnosed histologically. The salivary gland and pancreas had no clinical involvement in the hyperamylasemia. Saliva-type amylase was dominant as observed from amylase isozyme patterns in the serum and tumorous tissue. Levels of amylase were higher in tumorous tissue than in normal lung tissue. Immunohistochemical study showed amylase localized in tumor cells. Observation of the ultrastructure revealed electron-dense granules in the cytoplasm of the tumor cells. Findings suggested that amylase was being produced by the lung cancer in this case.

Regional cardiac sympathetic reinnervation in transplanted human hearts detected by 123I-MIBG SPECT imaging.

The purpose of this study was to assess the regional cardiac sympathetic reinnervation late (> or = 1 year) after heart transplantation (HTX) by means of 123I-MIBG (MIBG) scintigraphy. Eight patients with a pretransplantation diagnosis of idiopathic dilated cardiomyopathy underwent MIBG scintigraphy more than one year after HTX. The presence or absence of regional MIBG uptake was evaluated in each SPECT image, and global MIBG uptake was semi-quantitatively assessed by the heart to mediastinum ratio (H/M). Five of 8 patients had visible MIBG uptake in both planar and SPECT images (PU group), whereas 3 of 8 patients had no uptake, 2 of them after a period of 2 years, and one of them as long as 5 years after HTX, respectively (NU group). Positive regional MIBG uptake involved the basal anterior region in all 5 patients, the basal septal region in 4 patients, the basal lateral region in 3 patients and the basal posterior region in 1 patient. The H/M value was 1.24+/-0.10 in the PU group and 1.09+/-0.03 in the NU group. In conclusion, MIBG SPECT can detect regional sympathetic reinnervation, indicating that basal septal and lateral regions next to the basal anterior are more likely to be reinnervated, but reinnervation is much less likely to occur in the midventricular and apical regions.

Secondary malignant lymphoma which simulated primary thyroid cancer.

A patient with secondary thyroid lymphoma who complained of a neck mass was presented. Multiple nodules were detected in both lobes of the thyroid gland, which appeared as homogeneous hypoechoic masses on ultrasonogarphy (US), low-density masses on computed tomography (CT), and areas of increased uptake on gallium-67 scintigraphy. The residual thyroid gland was normal. Surgery established a diagnosis of secondary thyroid lymphoma with no coexistent Hashimoto's thyroiditis but with cervical node involvement by lymphoma. Radiologic evidence of normal residual thyroid gland in a patient with thyroid lymphoma may be a sign of secondary thyroid lymphoma.

[Case-control study of risk factors for cedar pollinosis among parents of 3-year-old children].

PURPOSE: To identify risk factors associated with cedar pollinosis among parents of three-year-old children. METHODS: The subjects were parents whose children underwent health examination at the age of three years in September and October 1997 in Tochigi prefecture. We distributed questionnaires to the examinees beforehand with the request that they be filled in and brought to the examination site. Information on parents' environmental factors (place of residence, type and structure of housing, and distance from roads with heavy traffic), and mothers' past history and family history of allergic diseases was obtained. We defined cedar pollinosis in terms of three symptoms, sneezing, nasal discharge, and nasal obstruction, between February and May. Controls were those who did not have any of the three symptoms. Environmental factors were assessed with univariate and multivariate analyses using unconditional logistic models. Maternal genetic factors were also analyzed with odds ratios and 95% confidence intervals calculated for each. We also compared odds ratios of environmental factors between groups with and without genetic factors. RESULTS: Of the parents of children taking the health examination, 90.2% took part (2,968 of 3,291 couples). Information was obtained from 2,846 mothers and 2,905 fathers. Mother and father cases were 312 and 229, and controls were 1,857 and 1,934, respectively. For the univariate analysis of environmental factors, place of residence (residential area/agricultural area), type of housing (apartment complex/solitary house), structure (reinforced concrete building/wooden house), and distance from heavy traffic (< 100 m/100 m+) were positively related to cedar pollinosis. For the multivariate analysis using unconditional logistic models, the odds ratio was significantly high for distance from heavy traffic (< 100 m/100 m+) among fathers. Mothers' past history and family history of allergic diseases showed high odds ratios for cedar pollinosis. We classified groups with and without past and family histories of allergic diseases (group with and without genetic factors) for assessment with multivariate analyses. Odds ratios for the group with an allergic history were higher than for those without such a history, but difference for factors such as, distance from heavy traffic type of housing, and structure were not statistically significant. CONCLUSION: Risk of cedar pollinosis increases with distance from heavy traffic among fathers. Mothers with histories of allergy show slightly elevated odds ratios for environmental factors, but without statistic significance.

[Relationship between breast milk and atopic dermatitis in children].

OBJECTIVE: To determine whether or not dioxins and furans in breast milk have a role in the prevalence of atopic dermatitis among children. METHODS: The target population of the study was all children participating in health check-up program for 3-year-old children in Tochigi Prefecture in September and October 1997. Using a questionnaire, information on nutrition in infants (breast milk only, bottled milk only, or mixed), parity, mothers' age at birth, and a history of atopic dermatitis was obtained. Besides, data on potential confounding factors were obtained. RESULTS: Questionnaires from 2,968 children (85.3% of those who were to participate in the programs, and 90.2% of children who participated them) were analyzed. The risk of atopic dermatitis was higher among children with breast milk (odds ratio [OR] = 1.37 with 95% confidence interval [CI] 1.02-1.83) and those with mixed nutrition (OR = 1.21, 95% CI: 0.94-1.57) in comparison with children with only bottled milk. Mothers' age at birth (OR for those who were more than 30 years or older in comparison with those who were younger than 30 years = 1.27; 95% CI, 1.01-1.62) and those with second or later parity orders (OR = 1.32, 95% CI; 1.04-1.67) were also risk factors of the dermatitis after the adjustment for some potential confounding factors. CONCLUSION: Breast milk elevates the risk of atopic dermatitis slightly; the risk is, however, higher in children in second or later parity orders. If the PCDDs and PCDFs in breast milk cause the dermatitis, this would contradict the assumed metabolism of these chemicals in human bodies.

[99mTc-HMDP accumulation in soft tissue tumor].

Accumulation with bone scintigraphy using technetium-99m hydroxymethylene diphosphonate (99mTc-HMDP) in 68 cases with radiographically or pathologically verified soft tissue tumor was examined. Radiographical or histopathologic diagnoses of the 68 cases included; 14 lipomas, 11 liposarcomas, 11 neurinomas or neurofibromas, 6 malignant lymphomas, 5 malignant fibrous histiocytomas, 5 hemangioma, rhabdomyosarcomas, 2 Langerhans cell histiocytoses, 2 desmoid tumors and one each of neuroblastoma, hemangiopericytoma, angiomyxoma, plasmacytoma, liomyosarcoma, lymphangioma, fibrosarcoma, elastofibroma, synovial sarcoma, and ganglion. Thirty-seven (54%) showed positive accumulation and 31 were negative. One half of soft tissue tumors can be accumulated by 99mTc-HMDP.

[Evaluation of myocardial uptake of beta-methyl-(123I)-iodophenylpentadecanoic acid (123I-BMIPP)].

To evaluate the myocardial uptake of beta-methyl-(123I)-iodophenylpentadecanoic acid (123I-BMIPP), nineteen patients with ischemic heart disease including left ventricular hypertrophy (mean age 63 +/- 7.8, 14 males and 5 females) underwent BMIPP myocardial scintigraphy. Myocardial uptake (MU) of BMIPP to the total injected dose was calculated from anterior view of the planar image in all subjects, and was compared with plasma glucose (BS), triglyceride (TG), and free fatty acid (FFA). It was also compared with left ventricular mass (LVM) calculated with echocardiography. MU was not related to BS, TG, and FFA, however had the positive correlation with LVM (r = 0.676, p < 0.01). Myocardial uptake per left ventricular mass (MU/LVM) had the negative correlation with LVM (r = -0.671, p < 0.01). Further studies for the significance of MU/LVM will be required.

[Quantitative analysis of 123I-metaiodobenzylguanidine myocardial scintigraphy by myocardial uptake using a phantom].

To evaluate the quantitative analysis of 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, total injected dose measured by first pass (FP) method (TFP) was compared with that measured by phantom method using an acrylic phantom in 45 patients with cardiac disease. Heart per mediastinum ratio (H/M) was compared to myocardial uptake calculated with TFP. The total injected dose measured using the phantom in which the syringe was set in depth of 3.5 cm (Tpham) was correlated with TFP (r = 0.73, p = 0.0001). When Tpham was corrected by body weight (c-Tpham), c-Tpham showed better correlation with TFP. MU calculated by TFP (MU-FP) was well correlated with MU by c-Tpham (MU-pham) (r = 0.94, p = 0.001). These results indicate that phantom method is sufficient to substitute for FP method. Though H/M was correlated with MU-FP (p < 0.001), the interpatient variation was relatively large. Then the analysis by H/M is insufficient to substitute for the myocardial uptake. It is though to be enough to use the phantom method on daily routine work, since this method is accurate and easy to quantitate the myocardial uptake of MIBG taking a short time.

[Artifactual defect of inferior myocardium on 123I-metaiodobenzylguanidine myocardial SPECT: characteristic findings and preventive method on phantom study].

Discordance between planar and SPECT image of inferior myocardial defect on 123I-metaiodobenzylguanidine myocardial scintigraphy (MIBG) was occasionally observed in the clinical studies. The purpose of this study is to clarify the existence of artifactual myocardial defect on MIBG SPECT image. Phantom study was performed in various kinds of situation using triple gamma camera. Artifactual defect adjacent to the liver was significantly observed in the case of increased liver/heart uptake ratio more than 2:1. Artifactual defect was markedly observed in the 180 degrees than that in the 360 degrees SPECT acquisition. To avoid artifactual defect during SPECT acquisition, liver phantom was moved down to the foot direction (vanishing liver position). In this phantom position, artifactual defect adjacent to the liver was not observed on reconstructed myocardial SPECT image. The vanishing liver position was also applicable to human study. Human body was inclined to right side at an angle of 15 degrees, artifactual defect could be avoided. Further study is needed to analyze the cause of this artifactual defect and to conform the preventive method with vanishing liver position in the routine myocardial SPECT examination.