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Biomedical subjects

M Furuse

Publications and source records attributed to M Furuse.

302 records · Page 17Linked to original sources
PubMedDate not supplied

Venous sac embolization of pulmonary arteriovenous malformation: preliminary experience using interlocking detachable coils.

PURPOSE: To evaluate the indication and advantages of venous sac embolization of pulmonary arteriovenous malformations (PAVMs) using interlocking detachable coils (IDCs). METHODS: We performed percutaneous embolization in 12 PAVMs in four patients using IDCs, initially placed in the venous sac or at the feeding artery to prevent systemic migration of additional coils. We placed the IDCs in the venous sac in PAVMs with the following vascular architecture: the draining vein was larger than the feeding arteries and both vessels were interposed with the venous sac or there were short feeding arteries. RESULTS: Complete occlusion was achieved in all 12 PAVMs without significant complications. We deployed IDCs in the venous sac in eight PAVMs and in the feeding artery in four. CONCLUSION: Venous sac embolization may be beneficial in PAVMs with large out-flow vessels or short feeding arteries. IDCs are suitable for this procedure.

Adult↗
PubMedDate not supplied

Assessment of T1 time course changes and tissue-blood ratios after Gd-DTPA administration in brain tumors.

Sequential T1 changes in brain tumor tissue after Gd-DTPA administration were investigated in 10 patients, including 4 meningiomas, 2 gliomas, 3 metastatic cerebral tumors and 1 brain abscess. T1 values were measured serially for 60 minutes following Gd-DTPA injection using a magnetic focusing technique. In vitro T1 of the whole blood samples was also comparatively examined. Time processes in the tissue-blood ratio (TBR) were calculated from two-point relaxation rates at 5 and 30 minutes. The obtained ratios of TBR were ranged from 1.0 to 3.0, probably depending on histological types of brain tumor (the value of 1.0 to 1.5 for meningioma and 1.5 to 3.0 for glioma and metastatic tumor). No significant changes in the T1 value were observed in the examined normal tissue and peritumoral edema. These results indicate that Gd-DTPA plays an important role not only as an image enhancer for tumor tissue but also as an indicator for estimating the blood-brain barrier function.

Adult↗
PubMedDate not supplied

Intracerebroventricular injection of fusaric acid attenuates the anorexia by glucagon-like peptide-1 in the neonatal chick.

It is known that central injection of glucagon-like peptide-1 (GLP-1) suppresses feeding in rats and chicks, but the systems for GLP-1 are still open with special reference to the chick. The present study was done to determine whether a noradrenergic mechanism contributes to the anorexigenic effect of GLP-1 on the neonatal chick. Central administration of norepinephrine (NE) suppressed food intake with narcolepsy as GLP-1 in chicks. However, in spite of that dopamine (DA) did not affect food intake, coadministration of inhibitor of dopamine-beta-hydroxylase (DBH), fusaric acid (FA), attenuated the suppressive effect of GLP-1 on feeding behavior. It is suggested that there may be the interactive relationships between GLP-1 and noradrenergic system in the neonatal chick.

Animals↗
PubMedDate not supplied

MR angiography of intracranial aneurysms: a comparison of 0.5 T and 1.5 T.

The objective of this paper is to compare the diagnostic efficacy of 3 DFT time-of-flight MR angiography (MRA) at middle-field-strength and high-field-strength in diagnosis of intracranial aneurysms. Thirty-one patients, including 26 patients with angiographically confirmed intracranial aneurysms (n = 28), underwent MRA at 0.5 and 1.5 T. Images were interpreted by six trained observers who were blinded to diagnosis. Twelve projections of MRA of the circle of Willis, by maximum-intensity projection algorithm, were reviewed using continuous confidence-judgement scales. It was found that MRA at 1.5 T was more sensitive than that at 0.5 T in detection of aneurysms. The sensitivity of six observers ranged between 50 and 64% (mean 56%) at 0.5 T, and between 61 and 86 86% (mean 75%) at 1.5 T. In the smaller aneurysms less than 5 mm, the differences between the units became greater. The sensitivity for small aneurysms ranged from 23 to 54% (mean 32%) at 0.5 T, and from 31 to 69% (mean 58%) at 1.5 T. Our conclusion was that high field strength confers higher accuracy in the detection of intracranial aneurysms with MRA with current-generation MR imagers.

Algorithms↗
PubMedDate not supplied

The use of deblurring technique for improving the longitudinal resolution in helical CT of the head and neck region.

We evaluated the use of deblurring technique by digital deconvolution for improving the longitudinal resolution in helical CT in a phantom and CT images of head and neck patients. After performing the helical scanning, overlapped axial images were reconstructed at 1/10 of the actual collimation. Then, the deblurring technique was performed. Results revealed that the resolution of slice profiles was improved after deblurring. Further, the longitudinal resolution increased as the strength of the deconvolution increased, at the expense of an increase in helical artifacts. The sharpness and visualization of horizontally running structures were improved in the reconstructed MPR, MPVR, MIP and 3D images in both the phantom and the images of all patients. Also, visualization of the peripheral vessels in CTAs was improved.

Angiography↗
PubMedDate not supplied

High level cross of the esophagus with the descending aorta in scoliosis: CT study.

OBJECTIVE: The esophagus occasionally crosses the descending aorta at an unusually high level (3-5 cm inferior to the carina) in right-sided scoliosis. The purpose of this study was to analyze the mechanism of this finding. MATERIALS AND METHODS: We prospectively evaluated thoracic CT scans in 30 patients with right-sided scoliosis. We assessed the alterations in the positions of the esophagus and the descending aorta by the thoracic deformity. RESULTS: The descending aorta followed the scoliotic curve of the spine in 26 (87%) patients. The esophagus followed the scoliotic curve of the spine in 14 (47%) patients and did not in 16 (53%). The anteroposterior diameter of the thorax in the former group was significantly smaller than that in the latter (p < 0.01). High level cross of both structures was identified in 14 (47%) patients, and all of them belonged to the group in which the esophagus did not follow the scoliotic curve of the spine. CONCLUSION: The unusual high level cross of the esophagus with the descending aorta occasionally seen in scoliosis is due to a difference in the positional alterations of the two structures resulting from the scoliosis.

Adolescent↗
PubMedDate not supplied

CT findings of pulmonary parenchyma in Takayasu arteritis.

PURPOSE: Our goal was to describe the pulmonary parenchymal manifestations of Takayasu arteritis visualized on CT. METHOD: We assessed the CT findings for the pulmonary parenchyma in 25 patients with Takayasu arteritis and compared them with those visualized by pulmonary angiography (n = 20) and radionuclide perfusion scintigraphy (n = 19). RESULTS: A review of the CT scans revealed a total of 33 low attenuation areas in the lung (11 patients), subpleural reticulolinear changes (12 patients), and pleural thickening (9 patients). The low attenuation areas were preferentially seen in patients with pulmonary arteritis and corresponded to pulmonary angiographic staining and scintigraphic perfusion defects. No significant correlation was found between other CT findings and pulmonary arteritis. CONCLUSION: The findings suggest that pulmonary low attenuation areas observed on CT represent regional hypoperfusion due to pulmonary arteritis. We speculate that pulmonary thromboembolism may contribute to other CT findings for the pleura and adjacent lung.

Adult↗
PubMedDate not supplied

Pulmonary vein and left atrial invasion by lung cancer: assessment by breath-hold gadolinium-enhanced three-dimensional MR angiography.

PURPOSE: The purpose of this work was to evaluate the ability of breath-hold gadolinium-enhanced three-dimensional (3D) MR angiography to assess the invasion of the pulmonary vein and the left atrium by lung cancer. METHOD: Gadolinium-enhanced 3D MR angiography was performed in 20 consecutive patients with lung cancer. RESULTS: At two sites with left atrial invasion shown by MR angiography, associated partial resection of the left atrium was performed. At five sites with invasion of the proximal pulmonary vein within 1.5 cm from the left atrium on MR, partial resection of the left atrium was performed at one site, and the pulmonary vein was resected at the intrapericardial portion at three sites. At two sites with invasion of the proximal pulmonary vein 1.5 cm more distal to the left atrium, the pulmonary vein was resected at the extrapericardial portion. CONCLUSION: Breath-hold gadolinium-enhanced 3D MR angiography is suitable for assessing invasion of the pulmonary vein and the left atrium by lung cancer.

Adult↗
PubMedDate not supplied

Lobar intracerebral hemorrhage: etiology and a long-term follow-up study of 32 patients.

Thirty-two patients with lobar hematoma were encountered during a period of six and a half years. Of these patients, 13 had arterial hypertension, 7 had other etiologies, and the remaining 12 were without apparent etiology. In 5 of these patients, cryptic angiomas were suspected from angiograms and CT scans. In one young patient, there was a later recurrence of hemorrhage that resulted in death. Our experience in this series and a review of the literature have led us to conclude that, in young normotensive patients with lobar hematoma, surgical intervention may be a reasonable consideration so that evacuation of the hematoma may be accomplished and a detailed search for small angiomatous malformations may be carried out with a view to preventing recurrences.

Adolescent↗
PubMedDate not supplied

Release and endogenous actions of the gastrin/cholecystokinin (CCK) family in the chicken.

The regulation of cholecystokinin (CCK) and gastrin release in the chicken and their endogenous actions are summarized. Both dietary protein and amino acids stimulated CCK releases. Among dietary fat sources, medium-chain triacylglycerol (MCT) was a potent stimulator of CCK release compared with long-chain triacylglycerol (LCT). However, it is difficult to explain that endogenous CCK released by those stimulators has an important role in the avian gastrointestinal physiology. Luminal acids may be an important regulator in pancreatic enzyme and fluid secretion. Gastrin (a regulator of luminal acid secretion) release was stimulated by food components, strongly by MCT, but not by LCT, and weakly by some amino acids, and was inhibited by luminal acids. Luminal acids controlled food passage from the crop. In conclusion, gastrointestinal physiology may be directly regulated by luminal acid rather than by the gastrin/CCK family in the chicken.

Amino Acid Sequence↗
PubMedDate not supplied

Transfer index of MR relaxation enhancer: a quantitative evaluation of MR contrast enhancement.

To clarify the effects of Gd-DTPA on biological water, we examined the effects of the compound on spin-lattice relaxation rate with various concentrations of gelatin solutions. The results indicate that the effects of relaxation rate of Gd-DTPA in biological water fundamentally correspond to those in aqueous solution. To evaluate the distribution of Gd-DTPA in tissues, we introduced a transfer index that represents the product of tissue-blood ratio of Gd-DTPA and the ratio of extracellular volume of a tissue based on the above findings. The index depends neither on dose of the compound nor on Larmor frequency. The clinical significance of the index was studied in patients with brain tumors. The indexes varied from 0.038 to 0.51, depending on the biological characteristics of the tumors. The transfer index may be used in the quantitative evaluation of MR relaxation enhancement, which may be applied to monitoring therapeutic efficacy and to estimating tissue perfusion.

Brain↗
PubMedDate not supplied

Development of a growable vascular graft.

A vascular graft that can grow with the growth of its recipient was developed. The graft implanted in the thoracic descending aorta grew slowly to the expected size within a year after implantation in puppies. Human saphenous vein was used as the substrate material. It was dipped into distilled water and sonicated, resulting in cell destruction, and followed by cross-linking with a polyepoxy compound to give both controlled biodegradability, hydrophilicity, and antithrombogenic properties. Four millimeter inner diameter (ID) grafts, enveloped with polyester mesh tubes of 10 mm ID, were implanted in 11 puppies. The diameter of the grafts grew to 9.5 mm from their original 4 mm. After 1 year, the graft walls that were reinforced with polyester mesh were covered with endothelial cells. The following requirements were provided in a growable graft: 1) antithrombogenicity in a small caliber graft; 2) ability to grow as well as to terminate growth. The polyester mesh tube, which was larger than the graft, caused arrest of growth at the expected diameter, whereas the growth rate was controlled by the degree of graft cross-linking. With this method, any size graft can be made by changing the size of the original graft and the polyester mesh tube around it.

Animals↗