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Biomedical subjects

M Jimbo

Publications and source records attributed to M Jimbo.

At least 109 records · Page 6Linked to original sources
PubMed1980

[An attempt to numerical diagnosis by computed tomography (author's transl)].

In the previous report, the authors described a method obtaining numerical values of 'standard deviation (SD)' and deviation coefficient (DC) from printed out data of a brain CT slice picking up the basal ganglia. In the report, using these values, a possibility of numerical discrimination between normal and abnormal was also discussed. In the present investigation, it was attempted to apply admissible linear discriminant analysis to numerical diagnosis using SD value and DC value. From fifty normal scans and fifty abnormal ones of proved pathology, the admissible linear discriminant function, as below, was extracted, its misdiscriminant rate being 7.6% theroretically. S=-0.4248(SD)-6.4709 (DC) S larger than or equal to -11.447; normal, S < -11.447; abnormal. By this analysis, 98% of abnormal scans and 92% of normal scans were correctly judged without referring to analogue display and actual misdiscriminant rate was 5.0%. Furtermore, for the purpose of confirming reappearance of this result, another twenty normal scans and twenty abnormal scans were investigated by this method. Only one normal scan was judged uncorrectly and all abnormal scans were judged correctly. Accordingly misdiscriminant rate of this sample was 2.5%. It would be emphasized that this method was useful for screeing examination by CT, not only because the total discriminant rate was high, but also false negative rate was relatively low.

Adolescent↗
PubMed1978

Quantitative investigation of the x-ray absorption coefficient in computed tomography. An approach to numerical diagnosis.

From printout data of 50 normal and 50 abnormal scans of a brain slice picking up the basal ganglia the numerical values of SD and DC were obtained and those values lying inside M + 2sigma were arbitrarily regarded as normal. By these criteria two cases (4%) were diagnosed as false negative and three cases (6%) as false positive, with a misdiagnosis rate of 5%.

Adolescent↗
PubMed1978

[Normal pressure hydrocephalus. Part 1. Dynamic study of CSF circulation in patients with normal pressure hydrocephalus (author's transl)].

To clarify the pathogenesis of normal pressure hydrocephalus (NPH), quantitative measurement of CSF dynamics was attempted using RI techniques. In this study results concerning RI ventriculography and RI transfer test from CSF to plasma were reported. "Barrier ratio" and regional cerebral blood flow study in NPH will be reported elsewhere. Fifty-three patients with chronic communicating hydrocephalus wer devided into two groups. Thus, twenty-seven cases were diagnosed as NPH according to clinical symptoms and signs, and others were considered as mere chronic communicating hydrocephalus without any NPH characteristics. Results are as follows: 1) 169Yb--DTPA ventriculography; In NPH group, there was longer retention of RI injected into lateral ventricle, and RI activity was not detected in the cisterna magna 60 minutes after the injection. These findings show remarkable delay of CSF flow in NPH patients. 2) Transfer test of 169Yb--DTPA from CSF to plasma; Immediately after the RI injection, Transfer ratio of RI activity from CSF to plasma was measured. It was revealed that intraventricular RI was more rapidly transfered to plasma in NPH group compared with in the control group, suggesting accelerated trans-ependymal absorption of RI in NPH group.

Aged↗
PubMed1978

[Cystic craniopharyngioma extending down into the upper cervical spinal canal (author's transl)].

A case of craniopharyngioma with a large cyst extending through the posterior fossa down into the upper cervical spinal canal was reported. The patient is a 14-year-old female who was operated on for the first time in 1970, because of a suprasellar calcified mass. Histological examination verified craniopharyngioma of adamantinomatous type. Since then, she had been operated three times because of deterioration of visual acuity. She was admitted for the fifth time in January, 1977, complaining of severe neck pain radiating bilaterally to the shoulders. Radiological examination demonstrated, besides the suprasellar tumor, a huge mass extending along the clivus down to the level of C3 of spinal canal. Anteroposterior diameter of bony spinal canal evidently enlarged in upper cervical region. Interpedicular distance also widened markedly in the same region. Laminae of C1-C3 vertebrae were abnormally stretched and the spinal cord was compressed posteriorly by the tumor. Suboccipital craniectomy verified a cystic tumor in the region of foramen magnum and cervical spinal canal. The medulla oblongata was pushed backward by the tumor. The cystic tumor was evacuated and the capsule of the tumor was partly resected, which was histologically verified as craniopharyngioma of squamous type. The patient was relieved from the neck pain after operation and discharged in April 1977.

Adolescent↗
PubMed1978

[Normal pressure hydrocephalus. Part 2. The evaluation of severity of cerebral dysfunction by measurement of "barrier ratio" and regional cerebral blood flow (author's transl)].

In the previous study, quantitative analysis of RI ventriculography was reported in fifty-three cases with chronic communicating hydrocephalus. In this study, according to the same criteria as that of previous report, fifty-three cases were divided into two groups, namely NPH group (twenty-seven cases) and control group, which were considered as mere chronic communicating hydrocephalus without and NPH chalacteristics. (twenty-six cases). Results of "barrier ratio (B.R.)" measurement and regional cerebral blood flow study in these cases are as follows: 1) "Barrier ratio" using of 99mTcO4-: Concerning about B.R. of 99mTcO4- there was no significant difference between NPH and control group. However it tends to be that shunt surgery is not so effective in NPH cases in which B.R. shows abnormally low value. 2) rCBF by 133Xe clearance method: Regional cerebral blood flow was diffusely decreased in NPH patients, especially in its frontal area, suggesting the frontal area would be more severely damaged in NPH cases. These findings leads us to the conclusion that whether the shunt surgery might be effective or not depends on severity of cerebral dysfunction and the cerebral dysfunction is clearly evaluated by RI technique mentioned above.

Adult↗
PubMed1977

[Computerized transverse axial tomography in intracerebral, intracerebellar and intraventricular hemorrhage (author's transl)].

Computerized transverse axial tomography (CT) of the brain is a recently developed method which allows non-invasive roentgenologic evaluation of intracranial diseases. The advent of CT represents a great advance in the diagnosis of a very wide variety of intracranial lesions, including cerebrovascular diseases. Especially, CT was found to be extremely informative in evaluating intracerebral, intracerebellar and intraventricular hemorrhage. The purpose of this report is to evaluate the clinical usefulness of CT in the diagnosis of intracranial hemorrhage. From the seven hundreds cases of various intracranial diseases hitherto examined by the EMI-scanner (160 X 160 matrix), twenty-three cases of nontraumatic intracranial hemorrhage were selected for the present study. Fifteen cases of fresh hemorrhage consisted of hypertensive cerebrovascular disease, arterio-venous malformation, aneurysm and unknown etiology, number of cases being six, three, four and two, respectively. All cases were examined within fifteen days after the ictus and the positive findings were obtained in all cases. The characteristic feature of the hematoma is the circumscribed and increased density area surrounded by the decreased density zone probably representing the accompanied brain edema. The sequential CT studies revealed that the hematoma area was gradually decreased in its density and finally transformed into the rather low density one in four weeks or so after the ictus. The smallest hematoma detected by CT was the cerebellar hematoma about five grams in weight, which was failed to be recognized by the angiography. In cases of the old hemorrhage, besides the decreased density area of the hematoma, such findings were obtained as cerebral atrophy, ventricular dilatation and porencephalic change. It would be concluded that CT study is the most useful aid at present available in the diagnosis of intracranial hemorrhage. The precise anatomic extent of the hematoma, associated brain edema, ventricular deformity and displacement and hydrocephalus are all readily assessed by CT.

Adolescent↗
PubMed1977

[A new technique for collection the cerebrospinal fluid from rat (authors transl)].

An attempt was made to collect the cerebrospinal fluid (CSF) of rat using a capillary phenomenon technique. Experiments were carried out in 76 rats anesthetized with pentobarbital sodium (Nembutal, Abbot. 50 mg/kg IP). The midline incision in the occipital region was made from 0.5 cm anterior to interauricular line of 4 cm in length. Exposing the atlanto-occipital dura mater by separating the nuchal muscles, the CSF was collected with a heparinized microtube (MICROPET. Bection, Dickson and Company) through a small hole made by a 18G syringe needle. Thus, 0.05-0.05 ml of the CSF could be readily obtained without mixture of the blood in 64 cases out of 76 trials, 84%. This simple technique is a useful way to get a small amount of CSF from little animals, such as rats.

Animals↗
PubMed1976

[Cerebrospinal fluid flow dynamics in cerebral infarction--Numerical study with RI Anger camera (author's transl)].

Although the cerebral blood flow dynamics in cerebral infarction has already been studied by many investigators, the CSF flow dynamics in cerebral infarction has not been well discussed. The purpose of this paper is to investigate CSF flow dynamics in chronic cerebral infarction by RI cisternography and our new quantitative method. In 12 patients with cerebral infarction, the flow of CSF was estimated following intrathecal injection of 169Yb-DTPA or 111In-DTPA. In this study, in addition to the conventional cisternograms, quantitative evaluation of CSF flow was performed in 6 patients by our method. Our previous work included the quantitative CSF flow dynamics in 26 various cerebral disorders using RI Anger camera. This method consisted of following procedure: 30 minutes after RI injection, RI activity was studied continuously for 30 minutes, afterwards playing back the record to calculate the changes of RI activity in the optimal regions of interest. These operations were performed with Anger camera, accessory digital ratemeter and tape-recorder. The changes of RI activity which appeared to be linear is called flow rate in our study for convenience. In this report, the region of interest was selected at Sylvian cistern. 6 patients had abnormal cisternograms consisting of reflux of tracer into the ventricle and delayed migration of tracer to the basal cisterns and diminished flow of tracer in the affected hemisphers. In 5 patients whose cisternograms could not demonstrate the laterality of RI perfsion over the cerebral hemishere, a marked difference of flow rate between right and left Sylvian cisterns was found. These findings probably indicated the correlation between cerebral blood flow dynamics and CSF flow dynamics in cerebral infarction. Moreover, it was confirmed that our method could be of clinical use to evaluate CSF flow dynamics quantitatively. The possible mechanisms of CSF flow disturbance in the affected hemisphere following cerebral infarction was discussed.

Adult↗
PubMed1976

[Existence of triphasic flow pattern in regional cerebral blood flow of prolonged unconscious patients (author's transl)].

Anticipating to get some new informations about the cerebral circulations of the comatous patients, two kinds of radioisotopic techniques were combined and applied to twelve unconscious patients of various etiologies. The first step was the conventional gas clearance method using xenon 133 as the indicator. Regional cerebral blood flows were measured at the six areas over each hemisphere. Immediately following this procedure, about 150 muCi of I-131 MAA (I-31 macroaggregated human serum albumin) were injected into internal carotid artery via the same catheter inserted already for the first procedure. Radioactivities of the head and lungs were measured and the relative shunt flow was calculated based on the formula already described elsewhere. Profil scanning of the whole body of the patient was also performed after the intracarotid injection of I-131 MAA. Consciousness states of the ten patients were all severely damaged and causes of the disturbed consciousness were various, including 5 of subdural hematoma, 2 of occlusive cerebrovascular disease, 2 of brain tumor and 1 of ruptured intracranial aneurysm. This investigation revealed the following results; 1) In all patients, regional cerebral blood flows were shown decreased over all areas detected. The regional cerebral blood flows could not be increased by 5% carbon dioxide inhalation, suggesting angioparalysis in these areas. 2) Graphical analysis of the clearance curves revealed triphasic flow pattern in rCBF in four cases. In three cases among the four, the intracarotid injection of I-131 MAA showed the radioisotope labelled particles were captured not only in the brain, but also in the lungs and the relative shunt flow calculated increased up to twice as much as normal controls. It indicates that some of the particles larger than the cerebral capillary size passed through the brain and were captured by the capillary net work of the lungs. From the above described data, it might be concluded that the initial rapid component of triphasic flow pattern in rCBF measurement does not represent the hyperemia of luxury perfusion of metabolic origin, but arteriovenous shunting blood flow, probably, through the precapillary thoroughfare channels which have been anatomically demonstrated by Hasegawa et al.

Adult↗