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Biomedical subjects

F Kinoshita

Publications and source records attributed to F Kinoshita.

At least 37 records · Page 2Linked to original sources
PubMed1993

Optimization of Butterworth filter for brain SPECT imaging.

A method has been described to optimize the cutoff frequency of the Butterworth filter for brain SPECT imaging. Since a computer simulation study has demonstrated that separation between an object signal and the random noise in projection images in a spatial-frequency domain is influenced by the total number of counts, the cutoff frequency of the Butterworth filter should be optimized for individual subjects according to total counts in a study. To reveal the relationship between the optimal cutoff frequencies and total counts in brain SPECT study, we used a normal volunteer and 99mTc hexamethyl-propyleneamine oxime (HMPAO) to obtain projection sets with different total counts. High quality images were created from a projection set with an acquisition time of 300-seconds per projection. The filter was optimized by calculating mean square errors from high quality images visually inspecting filtered reconstructed images. Dependence between total counts and optimal cutoff frequencies was clearly demonstrated in a nonogram. Using this nomogram, the optimal cutoff frequency for each study can be estimated from total counts, maximizing visual image quality. The results suggest that the cutoff frequency of Butterworth filter should be determined by referring to total counts in each study.

Brain↗
PubMed1993

Visualization of nasopharyngeal carcinoma with Tl-201 chloride and a three-head rotating gamma camera SPECT system.

Tl-201 SPECT was performed on 12 patients with nasopharyngeal carcinoma (NPC) by means of a three-head rotating gamma camera to evaluate whether or not Tl-201 SPECT was useful and reliable for assessing the tumor viability of NPC. Tl-201 clearly accumulated in the tumor in 3 patients before radiation treatment and increased Tl-201 uptake by the lesion ceased after the treatment. Three of 9 patients who were followed up after radiotherapy developed apparent local recurrence and Tl-201 SPECT clearly visualized these recurrent lesions. Tl-201 SPECT was very useful for assessing the tumor response to irradiation and for detecting local recurrent tumor. A high resolution SPECT system employing Tl-201 chloride is a new reliable and accurate diagnostic tool for the assessment of NPC.

Adult↗
PubMed1993

Usefulness of bone SPECT of the cervical spine: with special reference to separate visualization of the trachea and thyroid cartilage.

We applied bone SPECT for the examination of the cervical spine. A three-head rotating gamma camera SPECT system was employed for this study. The SPECT image disclosed 42.7% of abnormal accumulations in the skeleton not seen with planar imagings. SPECT could separately visualize the trachea and thyroid cartilage and also provided interpretation of abnormality in the anterior part of the vertebral body being difficult with planar imagings only. The trachea cartilage was seen in 55.4% and the thyroid cartilage was seen in 47.3% of patients with anterior neck density in planar imagings. SPECT clarified that marked cervical curvature and diffuse high uptake by the skeleton might cause high intensity of the anterior neck in planar imagings in the case of non-pathological change. We concluded that bone SPECT is a useful diagnostic tool in detecting occult lesion in the skeleton and to rule out extraskeletal accumulations in examination of the cervical spine.

Adult↗
PubMed1993

Demonstration of abnormal perfusion in the pons with high resolution SPECT and technetium-99m HMPAO in a patient with acoustic neuroma.

We detected a regional defect in the pons with ipsilateral cerebellar hypoperfusion in a patient with acoustic neuroma by brain SPECT with 99mTc HMPAO. A high spatial resolution SPECT system with three detectors equipped with fan-beam collimators was employed. This is the first report of a defect in the brainstem being visualized by perfusion SPECT and this method could make it possible to clarify the cause of a remote effect on the cerebellar perfusion by injury to the brainstem.

Cerebellum↗
PubMed1992

Putrescine-dependent invasive capacity of rat ascites hepatoma cells.

The effects of inhibitors of polyamine synthesis on the invasive capacity of rat ascites hepatoma (LC-AH) cells were examined by in vitro assay of penetration of the LC-AH cells through a monolayer of calf pulmonary arterial endothelial (CPAE) cells. Pretreatment of LC-AH cells with alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, before seeding them onto a CPAE cell monolayer and culturing them for 24 h in the absence of DFMO decreased the number of penetrating tumor cells time and dose dependently (about 35% of the maximal inhibition) without affecting their viability or proliferative activity. DFMO treatment caused a marked decrease in the intracellular level of putrescine but not of spermidine or spermine. The DFMO-induced decreases in invasive capacity and putrescine level were almost completely reversed by the addition of putrescine to the medium during pretreatment with DFMO or invasion assay but were not affected by exogenous spermidine or spermine. No change in the invasive capacity was observed when the CPAE cells were treated with DFMO and the LC-AH cells with methylglyoxal-bis(guanylhydrazone), an inhibitor of S-adenosylmethionine decarboxylase, which depressed the spermidine and spermine levels but increased the putrescine level in the LC-AH cells. These results suggest that intracellular putrescine modulates the in vitro invasive capacity of LC-AH cells.

Animals↗
PubMed1992

Giant hypertrophic gastritis and acute hepatitis associated with cytomegalovirus infection.

A 38-year-old man developed prominent hypoproteinemia after acute elevation of serum transaminase levels. Giant hypertrophy of the gastric mucosa, a short serum albumin half-life, and the absence of massive hepatocyte necrosis established the diagnosis of protein-losing gastropathy. The hypoproteinemia, gastric fold hypertrophy and hepatitis remitted spontaneously within 4 months. A high antibody titer against cytomegalovirus suggested an association between the viral infection and the patient's disease.

Acute Disease↗
PubMed1992

[Assessment of skull base involvement of nasopharyngeal carcinoma by bone SPECT using three detectors system].

SPECT of the skull was performed on twelve patients with histologically proven nasopharyngeal carcinoma using newly developed three detectors SPECT system (Toshiba GCA 9300A) mounted with fan-beam collimators, for the purpose of early detection of skull base involvement of the disease. This SPECT system has extremely improved resolution with FWHM of 8 mm in the center, and it provides clear tomographic images of the skull which has anatomically complex structure. SPECT image was taken 3 hours after injection of 740 MBq (20 mCi) of 99mTc-MDP following whole body skeletal survey. In twelve patients with confirmed nasopharyngeal carcinoma, 8 patients showed positive findings on SPECT. Three of SPECT positive patients also showed destructive findings on CT. Other five positive patients did not show destructive findings on CT at their initial examinations, but in three of them CT findings turned to positive later. SPECT was superior to CT in early detection of skull base involvement. We believe that SPECT of the skull is a diagnostic tool for early detection of skull base involvement of nasopharyngeal carcinoma.

Adult↗
PubMed1991

Coping style of schizophrenic patients in the recovery from acute psychotic state: a preliminary study.

This study was undertaken to clarify a clinically effective coping style of 13 schizophrenic patients during recovery from an acute psychotic state. Sixteen recovered depressives served as the control group. A comparison of the coping behavior profile between the two groups revealed that changes in physical activity were significantly more frequent in the schizophrenics (62%) than in the depressives (25%).

Acute Disease↗
PubMed1991

Induction of ornithine decarboxylase by sialagogues in a human parotid gland adenocarcinoma cell line.

Ornithine decarboxylase in a human parotid gland adenocarcinoma cell line was induced by both cholinergic (carbachol) and beta-adrenergic (isoproterenol) sialagogues. The enzyme protein level, measured with anti-peptide antiserum, as well as the enzyme activity, was found to be high in unstimulated cells and to increase approximately 2-fold on stimulation, while the mRNA level increased 3-4 fold, as revealed by Northern hybridization. The rise in activity was completely blocked by the simultaneous addition of antagonists or actinomycin D. These results suggest that receptor-mediated stimulation of ornithine decarboxylase activity by sialagogues involves alterations in the level of mRNA and that the proliferative responses of human parotid cells to these sialagogues resemble those of the murine parotid gland.

Adenocarcinoma↗
PubMed1991

[Diagnosis of pancreatic cancer using 201Tl-chloride and a three-head rotating gamma camera SPECT system].

201Tl SPECT was performed on 17 patients with pancreatic cancer or chronic pancreatitis using a three-head rotating gamma camera SPECT system. In 7 of 10 patients with pancreatic cancer, the lesions were clearly delineated by 201Tl SPECT. Whereas the lesion of 30 mm in diameter was visualized, a large tumor of 80 mm in diameter could not be visualized. Namely, it was thought that 201Tl uptake by pancreatic cancer might be well correlated with tumor blood flow and/or its histological subtype rather than with tumor size. In 5 of 7 patients with chronic pancreatitis, no uptake by the pancreas was shown. The sensitivity, specificity, and accuracy in diagnosing pancreatic cancer by 201Tl SPECT were 70%, 71%, and 71%, respectively. The present results obtained by 201Tl SPECT were thought satisfactory enough to evaluate pancreatic cancer under the present conditions where there was no useful imaging agent for visualizing pancreatic cancer by SPECT. 201Tl SPECT is expected to be a new diagnostic tool for investigation of pancreatic tumorous lesion.

Adenocarcinoma↗
PubMed1991

[Blood flow measurement of brain tumor by 123I-IMP using 3-heads rotating gamma camera SPECT].

Using 3-heads rotating gamma camera SPECT system, regional blood flow was measured from the super-early image obtained 4 to 6 minutes after the intravenous injection of 123I-IMP on 11 patients with various brain tumors. Two cases of olfactory groove meningioma and malignant astrocytoma showed significantly high 123I-IMP uptake by the lesion visualized by MRI compared to the uptake by normal brain cortex on super-early image but 123I-IMP uptake by the tumor decreased on early image. In both cases, blood flow of the tumor measured from super-early image showed values much higher than those of normal brain cortex. It was thought that usual correction method based on early image did not correctly represent the blood flow of the lesion but that the present method based on super-early image could show the increase of blood flow of the tumor.

Adult↗
PubMed1990

[Factor analysis in thallium-201 chloride thyroid studies].

Factor analysis was applied to thyroid thallium-201 imaging to get separated image of tumor from normal thyroid tissue. Thirty-eight patients with various thyroid tumors which were histologically confirmed were included in this study. Following intravenous injection of 111 MBq (3 mCi) of 201Tl chloride, thyroid images in 64 frames were taken for 30 to 60 minutes using Toshiba gamma camera system and data were analyzed by 2 or 3 factor analysis. In 28 of 38 patients separated images of the lesions from normal thyroid were obtained and time-activity curves of various shapes corresponding to the lesions were also obtained. When the curves were classified into 3 groups according to their shapes: increasing, flat and decreasing, follicular carcinoma did not show increasing shape whilst neither of papillary carcinoma, squamous cell carcinoma and anaplastic carcinoma showed decreasing shape. The shapes of the curves were thought to be reflected in clearance of the agent from the lesions. Factor analysis in 201Tl chloride thyroid scan provided separated image of tumor from normal thyroid gland automatically and the obtained curves corresponding to the lesions provided information for estimating the characteristics of thyroid tumors.

Adult↗
PubMed1990

[Tumor imaging using 99mTc-hexamethylpropyleneamine oxime].

Tumor imagings have been performed in 32 tumor sites in 28 patients with a variety of malignancies by using 99mTc-HM-PAO. They have been compared with radionuclide angiography and conventional tumor imagings such as 67Ga citrate or 201TlCl scanning, and then their possible values have been evaluated for the investigation of tumor blood flow. Tumors were clearly visualized in 19 out of 32 sites, with 59% of positive rate. Good correlation was observed between the radioactivity in the tumor site on static image of 99mTc-HM-PAO and the radioactivity at arterial phase on radionuclide angiography, which represents tumor blood flow. The radioactivities in the marginal regions tended to be stronger than those in the center of large tumors. These results indicated that tumor imaging by 99mTc-HM-PAO mainly reflected tumor blood flow. On the other hand, 99MTc-HM-PAO imagings were not well correlated with 67Ga-studies, while they were coincided with all 201Tl scannings performed. It suggested that the affinity of 99mTc-HM-PAO to capillary wall also involved in its accumulation in the tumor. In conclusion, tumor imaging by 99MTc-HM-PAO was able to estimate tumor blood flow, and this examination would be helpful for the management of malignancies.

Adult↗
PubMed1989

Two cases of adenocarcinoma of the lung in which thallium-201 gave a better delineation of metastatic lesions than gallium-67.

The authors report two cases of adenocarcinoma of the lung in which Tl-201 gave a better delineation of metastatic lesions than did Ga-67. In the case of multiple bone metastases, the metastatic lesion of the skull was clearly demonstrated by Tl-201 but not by Ga-67. In another case of multiple brain metastases, the lesions were also visualized by Tl-201 but not by Ga-67. Tl-201 is occasionally superior to Ga-67 for visualizing metastatic adenocarcinoma of the lung.

Adenocarcinoma↗