Biomedical subjects

Hisato Ikeda

Publications and source records attributed to Hisato Ikeda.

6 recordsLinked to original sources

PubMed2005

Evaluation of hyperacute stroke using perfusion computed tomography.

Evaluation of the cerebral circulation dynamics in patients with stroke soon after onset is extremely important for planning the optimum treatment. Perfusion computed tomography (CT) was evaluated in 118 patients with stroke within 10 hours of onset in whom initial CT showed no ischemic change. The mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV) perfusion CT maps were visually evaluated in three slices covering the body of the lateral ventricle, the basal ganglia, and the pons, and the ratios of the values in regions of interest (ROIs) in the ischemic lesion and the symmetrical location in the opposite hemisphere were calculated (ROI ratio of regional (r) MTT, rCBF, and rCBV). The location of occlusion was confirmed by angiography performed on the same day in 106 cases and the location of infarction by later magnetic resonance (MR) imaging. MTT maps correctly identified 44 of 46 cases of ischemia in the carotid system, 20 of 29 cases of ischemia in the vertebrobasilar system, and 11 of 35 cases of ischemia in perforator regions. Eight cases could not be identified by perfusion CT, angiography, or MR imaging. The ROI ratios at the upper boundary of infarction (n = 18) were: rCBF 0.574 +/- 0.220 (mean +/- SD) and rCBV 0.972 +/- 0.276, and at the lower boundary of non-infarction (n = 24) were: rCBF 0.504 +/- 0.247 and rCBV 0.815 +/- 0.169; showing a statistical significance of p = 0.348 for CBF and p = 0.026 for CBV (unpaired t-test). The perfusion CT MTT maps correlated well with the angiographical findings for the carotid system, but poorly for the vertebrobasilar system and the perforator regions. A rCBF ratio of 0.5 and rCBV ratio of 0.9 were established for the boundaries of ischemia.

Aged↗

PubMed2005

Three-dimensional computed tomography angiography of the galenic system for the occipital transtentorial approach.

The venous variations of the galenic system were evaluated using three-dimensional computed tomography angiography (3D-CTA) to assess the influence on the occipital transtentorial approach in 150 patients who underwent 3D-CTA as a routine screening examination for cerebrovascular diseases. The variations of the vein of Galen with its tributaries, the tentorial sinus, and the veins around the tentorium were evaluated in multiple intensity projections and stereoscopic images. The angle between the vein of Galen and the straight sinus was 67.1 +/- 31.9 degrees (mean +/- SD). Observation of the pineal body from the direction of the approach tended to extend to the quadrigeminal bodies in acute angle cases, and to the third ventricle in obtuse angle cases. Bilateral internal cerebral veins (ICVs) joined in the anterior portion were associated with a long vein of Galen, or in the posterior portion with a short vein of Galen. The distance between the bilateral ICVs was 4.66 +/- 2.28 mm (mean +/- SD), and the shape of the space could be classified as spindle, parallel, hairpin, and round types. The basal vein could be classified into well-developed, hypoplastic, hardly recognized, and mimicking two basal veins because the tributary did not join but ran parallel to the basal vein. The drainage pathways lead to the anterior or posterior portion of the vein of Galen, the ICV, the tentorial sinus, and the superior petrosal sinus. The various types of the tentorial sinus and primitive tentorial sinus which might be sacrificed during section of the tentorium were confirmed. The inferior cerebral vein draining to the tentorial sinus could be seen. 3D-CTA could also demonstrate the presence, the course, and the drainage points of the internal occipital vein, the precentral cerebellar vein, the posterior pericallosal vein, and so on. 3D-CTA is useful to evaluate the variations of the venous system and the relationship with the tumor, and for preoperative simulation and intraoperative navigation of the occipital transtentorial approach.

Cerebral Angiography↗

PubMed2005

[A case of cerebellar tuberculoma].

We report a case of cerebellar tuberculoma presenting with headache, without any specific data. A 22-year-old male had headache for recent three months. Because of detection of the tubercle bacillus in his sputum, he was suspected the pulmonary tuberculosis and the tuberculous meningitis. On admission the cerebrospinal fluid revealed no abnormal data and the tubercle bacillus was not detected in the culture. We started medication for the tuberculosis. MRI demonstrated a mass lesion at the right cerebellum, suggesting the presence of a tuberculoma. He underwent total removal of the tumor via the supracerebellar route. Histological examination revealed tuberculoma when there are no abnormal data. The intracranial tuberculoma may be confused with an intracranial neoplasm. It is important to make an overall evaluation to diagnose tuberculosis; for instance, compromised high age, HIV, and the type of steroid administered, will increase intracranial tuberculoma. In this report, we describe a cerebellar tuberculoma without any abnormal data, suggesting that intracranial tuberculoma should be considered in the differential diagnosis of any intracranial mass lesion.

Adult↗

PubMed2004

Preoperative evaluation of the venous system for potential interference in the clipping of cerebral aneurysm.

BACKGROUND: Variations of the venous system affecting the surgical treatment of cerebral aneurysm were evaluated using three-dimensional computed tomography angiography (3D-CTA) to evaluate the essential aspects of preoperative diagnosis. METHODS: This study included 50 patients who underwent clipping of cerebral aneurysm through the pterional and trans-sylvan approaches. The 3D-CTA and operative findings were compared to assess the characteristics of cases in which the veins restrict brain retraction, hinder operative manipulations or require sacrifice because of the position in the operative field. RESULTS: Superficial sylvian veins that restricted brain retraction were identified in 8 cases. The veins entered the cavernous sinus in a relatively high position just below either the sphenoid ridge (superior lateral type) or the anterior clinoid process (superior medial type), and the veins entering at a more medial position were closer to the spatula and tended to be compressed or directly excluded (superior medial type). The inferior medial type did not tend to become tense and so did not restrict brain retraction. The inferior lateral type hardly affected the operative manipulation. The first segment of the basal vein of Rosenthal, the uncal vein entering the cavernous sinus, or the sphenoparietal sinus were located in the operative field in six cases, and affected the manipulation of dissecting arteries, and exposure and clipping of the aneurysm. CONCLUSIONS: 3D-CTA provides essential information for operative planning to protect the venous system during the pterional and trans-sylvian approaches.

Brain↗

PubMed2003

Duplex Doppler ultrasonography of subclavian steal syndrome--three case reports.

Three cases of subclavian steal syndrome were detected by duplex Doppler ultrasonography. Ultrasonography demonstrated retrograde flow with to-and-fro pattern in the right vertebral artery in two cases, and reflux with diastolic flow deceleration in one case. Interventional treatment with stenting was successfully performed in two cases and conservative treatment was given in one case. Ultrasonography is an effective noninvasive method for the evaluation of the vertebral artery, and should become a routine part of cerebrovascular examinations.

Aged↗

PubMed2003

Venous infarction resulting from sacrifice of a bridging vein during clipping of a cerebral aneurysm: preoperative evaluation using three-dimensional computed tomography angiography--case report.

A 67-year-old woman presented with a ruptured aneurysm of the left internal carotid artery bifurcation. Three-dimensional computed tomography angiography (3D-CTA) demonstrated the first segment of the basal vein of Rosenthal passing in front of the internal carotid artery and the anastomosis with the cavernous sinus, the partially hypoplastic second segment, and the superficial sylvian vein entering the lateral side of the sphenoparietal sinus. Dissection of the sylvian fissure toward the distal direction enabled transfer of the superficial sylvian vein to the temporal side, but the bridging vein had to be sacrificed to secure adequate operating space. Postoperative CT demonstrated hemorrhagic infarction at the left caudate head and surrounding region. Postoperative venous infarction is not an uncommon complication of various approaches. 3D-CTA can provide important information about the venous anatomy indispensable for avoiding postoperative venous infarction.

Aged↗