PubMed Health⌕ Search

Biomedical subjects

K Yasumori

Publications and source records attributed to K Yasumori.

At least 19 recordsLinked to original sources
PubMed2000

[A case of severe stenosis of bilateral distal vertebral artery successfully treated with anastomosis operation].

A 65-year-old male complained of loss of consciousness for several minutes, transient diplopia and dizziness. He had no neurological deficits nor abnormalities in MR imaging. However, flow velocity of bilateral vertebral artery on ultrasonography indicated severe stenosis of bilateral distal vertebral artery. Brain angiography revealed severe stenosis of bilateral distal vertebral artery as well as occlusion of right middle cerebral artery (MCA). Single photon emission CT (SPECT: ECD-RVR method with acetazolamide loading) showed decreased cerebral blood flow and poor perfusion reserve in bilateral cerebellar hemisphere and right MCA territory. Superficial temporal artery-superior cerebellar artery (STA-SCA) anastomosis was performed. The patient turned out to have no episodes of unconsciousness attack, transient diplopia and dizziness after operation. Cerebral blood flow (CBF) in the posterior circulation was also improved. Evaluating quantitative CBF measurement by means of ECD-RVR method was useful for evaluating CBF. In cases who have severe stenosis of bilateral distal vertebral artery with complaints of vertebrobasilar insufficiency, STA-SCA anastomosis may be one of the most effective treatments.

Aged↗
PubMed1995

[Selective intra-arterial injection of calcium for localization of insulinomas: proposed new criteria].

To elucidate whether noninvasive arterial stimulation venous sampling (ASVS) is helpful for localizing insulinomas, calcium gluconate (0.02-0.025 mEq Ca2+/kg) was injected directly into the gastroduodenal, splenic and superior mesenteric arteries of six patients with episodic hypoglycemia. In all six patients, there was a greater than 26-fold increase in serum insulin levels in blood samples obtained from the hepatic vein after the infusion of calcium into the artery supplying the tumor. However, in four of the six patients, such an injection into an artery not supplying the tumor resulted in a greater than twofold increase in insulin concentration. Accurate localization of the insulinomas was verified at surgery in all patients. We believe that these false positive results were caused mainly by the influx of calcium via branches of intrapancreatic anastomoses. In order to minimize false positive results, we have recommended the following new criteria for ASVS: maximum insulin concentrations exceeding 150 microU/ml in blood samples obtained from the hepatic vein, and greater than twofold increases in insulin concentration. We concluded that noninvasive ASVS is helpful in determining the location of insulinomas.

Adult↗
PubMed1994

MRI of the brain in chronic carbon monoxide poisoning.

We examined 13 patients with chronic carbon monoxide (CO) poisoning by magnetic resonance imaging (MRI); all of them had been in an explosion in a coal mine 25 years previously. Symmetrical globus pallidus lesions were observed in 12, as was degeneration of the white matter, with focal cortical atrophy. The temporal parietal and occipital lobes were usually affected, the parietooccipital region being the most frequently and extensively damaged. Of the 12 patients with white matter degeneration 7 had definitely asymmetrical cortical and subcortical lesions. There were 6 patients with dilated temporal horns, probably due to atrophy of the hippocampal gyri. A history of CO inhalation and an awareness of the typical distributions of lesions are important for recognition of the effects of CO poisoning, especially when patients are in the chronic stage.

Accidents, Occupational↗
PubMed1994

Management of tracheal and bronchial stenoses with the Gianturco stent.

Thirty-six cancer patients with symptomatic tracheobronchial stenoses received Gianturco tracheobronchial stents over a 9-year period. Symptoms improved in 28 patients (78%). The overall median survival was 1 month 3 weeks (range, 4 days to 35 months). The median survival for patients who showed improvement after receiving stents was 3 months compared with 1 week for those who did not respond. Complications were minimal. The Gianturco stent may palliate symptoms of tracheobronchial compression in selected cancer patients.

Adult↗
PubMed1993

Hepatocellular carcinoma: prospective assessments of the T-factor with CT, US, and MR imaging.

The capabilities of computed tomography (CT), ultrasonography (US), and magnetic resonance (MR) imaging were studied in order to determine the role of each of these noninvasive examinations for estimating the T-factor of hepatocellular carcinomas (HCCs). Fifty-one patients with surgically proven HCCs received CT (50 patients), US (46 patients), and MR (44 patients). The images of CT, US, and MR were prospectively evaluated for main tumor size, intrahepatic metastases, and vascular invasion, which compose the T-factor of HCC, and compared to pathological results. The sizes of the main tumor were estimated correctly by all examinations. For estimating intrahepatic metastases, US (74%) and MR (73%) were superior to CT (65%). For estimating portal invasion, CT (79%) was superior to US (70%) and MR (66%), because CT could demonstrate the segmental staining caused by portal invasion. The estimates of hepatic venous invasion were difficult during any of the examinations. We conclude that presurgical evaluations of the T-factor require the use of US and CT or MR and CT.

Aged↗
PubMed1993

Hepatocellular carcinoma: correlation of CT, angiographic, and histopathologic findings.

PURPOSE: To elucidate the causes of various enhancement patterns of hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Computed tomographic (CT) scans of 68 surgically resected HCCs (62 patients) were obtained 45 seconds and 6 minutes after administration of contrast material. These scans were compared with angiographic and histopathologic findings. RESULTS: On the early images, 24 HCCs (35%) were hypoattenuating, 33 were totally or partially hyperattenuating (48%), and 11 were isoattenuating (16%) compared to adjacent liver. On the delayed images, 55 HCCs (81%) were hypoattenuating and 13 (19%) were isoattenuating. Twenty-nine of the 48 very hypervascular or hypervascular tumors (60%) were hyperattenuating or partially hyperattenuating at early CT. Sixteen of the 20 slightly hypervascular or hypovascular tumors (80%) were isoattenuating or hypoattenuating. CONCLUSION: Although there was relatively good agreement between tumor vascularity and enhancement pattern (60% correlation for hypervascular tumors, 80% correlation for hypovascular tumors), hyperattenuation of the large HCCs (> or = 5 cm) at CT appeared to be a function of dilated sinusoids within the tumor (peliotic changes) as well as vascularity. In patients with advanced cirrhosis, hypovascular HCCs could be hyperattenuating at CT.

Angiography↗
PubMed1992

Rupture of embolised coeliac artery pseudoaneurysm into the stomach: is coil embolisation an effective treatment for coeliac anastomotic pseudoaneurysm?

An elderly woman with an anastomotic pseudoaneurysm of the coeliac artery, after previous treatment of a thoraco-abdominal aortic aneurysm, was treated by stainless steel coil embolisation. One year later, the embolised pseudoaneurysm ruptured into the stomach and total gastrectomy and aneurysmorraphy was necessary. She is leading a normal life 6 months later.

Aged↗
PubMed1992

Splenic hyperkinetic state and splenic artery aneurysm in portal hypertension.

Forty-eight out of six hundred and thirty patients with portal hypertension undergoing a celiac angiography series were diagnosed as cases of splenic artery aneurysm during the period 1977-1988. The case-control study of patients with portal hypertension with splenic artery aneurysms and those without was designed to characterize the angiological features. The splenic arterial flow was assessed by measuring the radii of the splenic arteries on celiac arteriograms. In the portal hypertensive patients with splenic artery aneurysms, the splenic artery was larger (p < 0.05) and the splenic arterial flow greater (p < 0.05), and these patients were in a more hyperkinetic state, than were those with no splenic artery aneurysm. The study suggests that splenic artery aneurysms in cases of portal hypertension may be the consequence of a hyperkinetic state in the spleen.

Adolescent↗
PubMed1991

[MR imaging in paranasal and intracranial aspergillosis].

The MR findings in three patients with paranasal and intracranial aspergillosis were analyzed. Two patients had sphenoid sinus aspergillosis with mucocele, and one had aspergillosis in the maxillary sinus and pachymeningitis in the posterior fossa. In all patients with aspergillosis of the paranasal sinuses, a markedly hypointense area was present within the lesion on T2-weighted images. In the patient with pachymeningitis, contrast-enhanced MR images clearly demonstrated the extent of the lesion.

Aspergillosis↗
PubMed1991

[MRI of brain abscesses].

Four cases of brain abscess were examined on 1.5T MR and their findings were evaluated retrospectively. Preoperative cases had relatively characteristic findings, such as 1) peripheral edema producing hypointensity on T1-weighted images (T1WI) and hyperintensity on T2-weighted images (T2WI); 2) central necrosis with abscess fluid hypointense relative to white matter on T1WI and hyperintense on T2WI; 3) abscess rim iso- to hypointense on T2WI. Gd-DTPA enhanced T1WI carried further information; comparison of iso- to hypointense rim on T2WI (abscess rim) and enhanced area by Gd-DTPA on T1WI suggested that the former represented zone of macrophage infiltration.

Adult↗
PubMed1991

Lateral ventricular arteriovenous malformations: natural history and surgical indications.

The authors report 21 cases of lateral ventricular arteriovenous malformation (AVM) focusing on their natural history and surgical indications. Eighteen of 21 patients (86%) had bleedings prior to admission. We performed definitive surgery in 9 patients and conservative treatment in 12 patients. In 7 of 9 patients (78%) in the operative group and in 5 of 12 patients (42%) in the non-operative group, the nidus of the AVM was less than 4 cm in diameter. The other 2 AVMs in the operative group, more than 4 cm in diameter, were located in the temporal lobe and widely extended to the temporal horn of the lateral ventricle. The nidi of the AVMs were totally removed in all 9 cases in the operative group. All patients have been doing well except one who had a mental breakdown 6 years after surgery. In 10 patients in the non-operative group, AVMs were located in the left cerebral hemispheres. Three patients in the non-operative group had rebleeding of the AVM. Two of the 12 patients in the non-operative group (17%) died of the recurrent haemorrhages. The rate of bleeding of the lateral ventricular AVM seems to be higher than that of the cerebral cortical AVM, but the mortality due to recurrent bleeding might be similar between the two. The operative indications we made depended on the sizes and locations of the AVMs. For AVMs in the temporal horn, even though they were large, we performed total removals of the nidi and had good results. We did not perform any definitive surgery for AVMs more than 4 cm in diameter except for those in the temporal horn. The mortality and morbidity of the 21 cases were 10% and 14%, respectively. Patients with AVMs in the temporal horn and patients with small AVMs in the frontal horn were good candidates for definitive surgery. We undertook conservative treatment for patients with large AVMs, and the results were acceptable.

Adolescent↗
PubMed1991

Arterioenteric fistulae: diagnosis and treatment by angiography.

Two cases of massive gastrointestinal haemorrhage caused by arterioenteric fistulae are presented. In both cases, bleeding was controlled by interventional angiography. In the first case, a fistula between an aberrant right subclavian artery and a reconstructed oesophagus was temporarily occluded with a balloon catheter as a pre-surgical measure. In the second case a communication between the external iliac artery and the colon in a patient with invasive cervical cancer was treated by embolization. An arterioenteric fistula should be considered as a possible cause of acute gastrointestinal haemorrhage in post-operative or cancer patients and aortography or pelvic arteriography may be required to make the diagnosis.

Catheterization↗
PubMed1991

Hemifacial spasm caused by CP angle AVM associated with ruptured aneurysm in the feeding artery--case report.

A 66-year-old male presented with clinical features of hemifacial spasm. Cerebral angiograms disclosed an arteriovenous malformation (AVM) in the cerebellopontine angle. The hemifacial spasm was caused by a dilated feeding artery of the AVM compressing the facial nerve at the root exit zone. Surgery was not initially performed because of his age and absence of AVM rupture. However, the AVM was associated with a small aneurysm in the feeding artery, which rapidly grew during 20 days after discharge and ruptured causing subarachnoid hemorrhage. The aneurysm was clipped and the feeding artery of the AVM partially obliterated. Careful angiographic examination for associated aneurysms and consequent surgical obliteration to prevent hemorrhage are suggested in cases of AVM.

Aged↗
PubMed1991

Transcatheter embolization of testicular vein for varicocele testis.

Percutaneous transcatheter embolization of the testicular vein was performed on 28 patients with angiographically proven varicocele testis. In 2 patients bilateral and in 26 only the left vein was embolized using 3-, 5-, or 8-mm stainless steel coils. All patients had clinically palpable varicoceles and male infertility. The grade of varicoceles improved after embolization in 23 of 28 cases (82%). Effective sperm count increased significantly from 34.5 +/- 44.6 to 65.1 +/- 71.0 following embolization. However, pregnancy was achieved only in one of 28 cases. Technically, the basilic vein approach was felt to be superior to the femoral vein or jugular vein approach for this procedure.

Adult↗
PubMed1990

Neuronal migration anomalies causing extensive ventricular indentation.

Neuronal migration disorders include various anomalies of the brain, and cortical heterotopia is the most common type. In this report, we present the radiological findings of two adults with unusually large cortical heterotopia associated with fused-lip schizencephaly that caused extensive ventricular indentation. The lesion showed density on a computed tomographic scan and signal intensity on a magnetic resonance imaging scan similar to normal gray matter. Perifocal edema, contrast enhancement, and calcification were not seen. An abnormally decreased volume of the ipsilateral cerebral hemisphere, the presence of adjacent microgyri, and deep fissures that contained blood vessels were also characteristic findings, indicating abnormal development. Knowledge of this entity is important in differentiating true intracerebral neoplasms.

Adult↗
PubMed1990

Magnetic resonance imaging compared with computed tomography and angiography in moyamoya disease.

Magnetic resonance (MR) imaging performed in 13 patients with moyamoya disease was reviewed and compared with computed tomography (CT) and angiography. The MR findings consisted of occlusion of arteries, collateral vessels and parenchymal changes. Narrowing or occlusion of the middle cerebral artery and the supraclinoid portion of the internal carotid artery were seen in all hemispheres but one. Collateral vessels, cerebral infarcts and atrophy with dilatation of the ventricles were observed on MR imaging. In general, the MR findings correlated well with angiography regarding occlusive changes and moyamoya vessels but was less sensitive in a few cases. Because of its higher sensitivity in detecting occlusive changes and collateral vessels, MR imaging was superior to CT in the diagnosis of this disease.

Adolescent↗