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Biomedical subjects

M Iio

Publications and source records attributed to M Iio.

At least 91 records · Page 5Linked to original sources

A research method for MRI tissue characterization studies using small coils for excised organs.

The main purpose of this report is to describe our method of MRI tissue characterization studies, which consists of MR imaging of the patient, precision MR imaging of the excised organ, and pathological examination of the organ. We first made small coils to be used with conventional MRI scanners to examine the excised organs. In order to make it easier to understand the effectiveness of our method, three illustrative case reports of abdominal or pelvic tumors were presented as examples of the tissue characterization studies. In conclusion, this method seemed very useful and, in addition, it was found that this small coil technique has several advantages in other applications.

Abdominal Neoplasms↗

CNS changes in Usher's syndrome with mental disorder: CT, MRI and PET findings.

CNS changes in a case of Usher's syndrome associated with schizophrenia-like mental disorder were observed by CT, MRI and PET. The neuro-radiological findings of the case demonstrate the degenerative and metabolic alterations in various regions of cortex, white matter and subcortical areas in the brain. Mental disorder of the case is almost indistinguishable from that of schizophrenia, but the psychotic feature is regarded as an atypical or mixed organic brain syndrome according to the classification in the third edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-III).

Adult↗

Hepatocellular carcinoma and cavernous hemangioma: differentiation with MR imaging. Efficacy of T2 values at 0.35 and 1.5 T.

Seventy-two patients with hepatocellular carcinoma (hepatoma) and 56 with hemangioma were studied with magnetic resonance (MR) imaging at 0.35 or 1.5 T to evaluate the efficacy of T2 values in differential diagnosis. T2 values were calculated with the two-point method. The mean T2 values of hepatoma and hemangioma were 58.9 msec +/- 8.9 and 101.6 msec +/- 25.8 at 0.35 T and 49.1 msec +/- 9.8 and 85.3 msec +/- 21.2 at 1.5 T. The difference in the T2 values for hepatoma and hemangioma was statistically significant (P less than .001) at both 0.35 and 1.5 T. Fifty-three of 56 lesions (94.6%) at 0.35 T and 86 of 102 lesions (84.3%) at 1.5 T were correctly classified when the T2 borderline between hepatoma and hemangioma was set at 80 msec. All misdiagnosed lesions were hemangioma, and all but one were smaller than 2 cm. However, over 90% of lesions smaller than 2 cm were correctly diagnosed when 70 msec at 0.35 T and 60 msec at 1.5 T were used as borderline T2 values. MR imaging with T2 measurement was very useful for differentiating between hepatoma and hemangioma (including small lesions) at 1.5 T as well as at 0.35 T.

Adult↗

[Prospective study to assess the clinical efficacy of bone scintigraphy--comparative study of the efficacy in breast carcinoma and prostate carcinoma].

Prospective study of bone scintigraphy was performed on 414 patients with breast carcinoma and 88 patients with prostate carcinoma. In 468 of them, confirmative diagnoses of bone, whether metastasis was existent or not, were made after the observations over a year. Finally, the incidences of bone metastasis were 11 percent for breast carcinoma and 54 percent for prostate carcinoma respectively. The efficacy of preoperative bone scintigraphy in breast carcinoma was comparable to that in prostate carcinoma with regard to improvement of predictive probability of bone metastasis: raising up the probability in the positive cases and bringing down in the negative cases.

Bone Neoplasms↗

[Prospective study to assess the clinical efficacy of bone scintigraphy--some analyses of clinical data].

The value of preoperative bone scans in patients with primary breast and prostate cancer was evaluated prospectively. Of 414 patients with breast cancer, clinical stage I is 14, II is 219, IIIA is 59, IIIB is 39 and IV is 14. Of 88 patients with prostate cancer, clinical stage I is 14, II is 15, III is 18 and IV is 41. 11 percent of patients with breast cancer and 54 percent of patients with prostate cancer had bone metastases. Clavicle, ribs, thoracic spine, lumbar spine and pelvis metastasized most frequently. The incidences of bone metastases were 18.4% with Scirrhous carcinoma, 15.4% with Medullary tubular carcinoma and 3.8% with Papillotubular carcinoma. The methodology and results of ROC analysis were described in our other papers. Some results of data analysis were described in this paper.

Adult↗

[Prospective study to assess the clinical efficacy of bone scintigraphy--ROC analysis].

The value of preoperative bone scans in patients with primaly breast and prostate cancer was evaluated prospectively. The methodology and some clinical results were described previously. The clinical efficacy of the bone scan was assessed by using ROC analysis and we obtained the following results. 1) Preoperative bone scan of carcinomas of the breast is effective for patients with clinical stage IIIA, IIIB and IV. It is not so effective for patients with clinical stage I and II, but there is no denying the importance of it, because it provides a base-line scan for comparison to subsequent scans obtained in the postoperative period. 2) Preoperative bone scan of prostate carcinomas is effective, especially for clavicle, the ribs and the cervical spine, when compared with bone X-ray. 3) Bone scan is effective means for patients who were diagnosed uncertainly to have bone metastasis.

Bone Neoplasms↗

[Positron emission tomography using pyruvate-1-11C on mitochondrial encephalomyopathy].

In order to investigate in vivo metabolism of pyruvate in the brain, positron emission tomography (PET) using pyruvate-1-11C were performed on two patients with mitochondrial encephalomyopathy, one patient with Leigh disease and one patient with epilepsy. PET images of epilepsy showed less RI uptakes in brain tissues than in skull muscles. And RI was cleared rapidly from the brain tissues. But PET images of mitochondrial encephalomyopathies showed increased RI uptakes and slow RI clearance in cerebral cortices, basal ganglia and thalamus. Also RI was cleared slowly or accumulated in ventricles. This suggested that pyruvate metabolism may be impaired with metabolical trapping of 11C by lactic acids, since it is said that 11C of pyruvate-1-11C is cleared rapidly from the normal brain tissues by decarboxylation of pyruvate. The usefulness of PET studies with pyruvate-1-11C are suggested for investigating pyruvate metabolism in brain tissues, and for diagnosing mitochondrial encephalomyopathy.

Brain↗

[Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease].

The distribution of cerebral blood flow and metabolism is related to neuronal activity. Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and oxygen extraction fraction (OEF) in ten patients with Parkinson's disease and five age-matched normal control subjects were measured with positron emission tomography (PET) using 15O2, C15O2 steady state inhalational technique to investigate functional changes of the cortex and the basal ganglia in Parkinson's disease. All patients had no history of cerebrovascular disease and CT scan showed no abnormal findings except for moderate cerebral atrophy in only one patient. When the level of clinical disability was related on the scale of Hoehn and Yahr, one patient was stage I, four were stage II, four were stage III, and one was stage IV. Psychic symptoms which include hallucination, depression, and dementia were recognized in four patients. One of these four patients was mildly demented. Four patients were newly diagnosed and had never been treated with antiparkinsonian medication before. Before the patients had their PET study their antiparkinsonian medication was discontinued for more than three days. But in two patients PET study was performed without discontinuity of antiparkinsonian medication. The values for regional CBF and regional CMRO2 were lower in the patients than in the normal control subjects, especially in the frontal cortex there was a significant decrease of CBF and CMRO2. There was no discrepancy between CBF and CMRO2 both in the patients and the normal control. CBF and CMRO2 in the cortex and the basal ganglia were not correlated with the severity of tremor, bradykinesia, and rigidity.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗