Publications by authors named "Kuniyuki Tashiro"

We report a 34-year-old male who manifested T shortening of the cerebral cortices after more than 86 contrast-enhanced MRI studies. We observed high-signal intensity (SI) on T-weighted images (TWIs) not only in the globus pallidus, dentate nucleus, and pulvinar of thalamus, but also in the cortices of the pre- and post-central gyri and around the calcarine sulcus. High SI in the cerebral cortices was not clearly demonstrated on TWI scans performed 11 years earlier.

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Purpose: We compared quantitative indices estimated by use of technetium-(99m) galactosyl human serum albumin ((99m)Tc-GSA) single-photon emission computed tomography (SPECT)/computed tomography (CT) fused imaging and hepatic fibrosis in patients with chronic liver disease.

Materials And Methods: On the basis of pathological findings we divided 161 patients into non-severe and severe fibrosis groups (n = 81 and n = 80, respectively). We measured 2 indices by (99m)Tc-GSA SPECT/CT fused imaging: liver uptake value (LUV) = [radioactivity (whole liver)/radioactivity (injected)] × 100/body surface area, and functional liver index (FLI) = [radioactivity (hepatocytes)/radioactivity (injected)] × 100/liver volume.

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As there is continuing controversy over the role of F-18-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT-fused imaging in radiation therapy (RT) planning, we performed a phantom study to assess the feasibility of FDG-PET/CT-based gross tumor volume (GTV) contouring. The phantom set, consisting of an elliptical bowl and 6 spheres measuring from 10-37 mm in diameter, were filled with FDG to obtain 3 source-to-background ratios (SBRs) of 4, 8, and 16. The ratio to maximum intensity at 5% intervals was applied as the threshold for contouring.

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Purpose: To evaluate the role of hepatic asialoglycoprotein receptor analysis in the preoperative estimation of postoperative hepatic functional reserve.

Methods: We obtained technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin (99mTc-GSA) SPECT/CT fusion images in 256 patients with liver disease scheduled for hepatic resection. The liver uptake value corrected for body surface area [LUV(BSA)] and liver uptake ratio (LUR) of the remnant were preoperatively estimated based on the fused images.

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Objective: Imperfect image resolution because of finite-sized collimator channels often causes a decrease in diagnostic performance in myocardial perfusion single-photon emission computed tomography (SPECT). This prompted us to evaluate the clinical usefulness of collimator distance dependent resolution recovery (RR) in myocardial perfusion SPECT.

Methods: We retrospectively reviewed myocardial SPECT images of 60 consecutive patients (26 men, 34 women; mean age 68 years).

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Purpose: To evaluate the advantages of a segmentectomy of the right upper lobe (RUL) over a right upper (RU) lobectomy regarding the preservation of the functional volume of the right middle lobe (RML), the postoperative forced expiratory volume in one second (FEV(1)) of the RML was compared between an RU lobectomy and an RUL segmentectomy, by using a coregistered perfusion single-photon emission computed tomography and computed tomography (SPECT/CT).

Methods: The pulmonary function tests and perfusion SPECT/CT were conducted before and after surgery (RU lobectomy: 7; RUL segmentectomy: 13). The FEV(1) of the RML before and after surgery was calculated from the data of the pulmonary function test and SPECT/CT.

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Purpose: I-123-labeled N-isopropyl-p-iodoamphetamine ((123)I-IMP) is used for the measurement of regional cerebral blood flow (rCBF). A continuous or single arterial blood sampling (ABS) is necessary to estimate an integral of arterial input function (AIF) for the measurement of rCBF by using a microsphere model analysis. Therefore, a method of measuring rCBF without any blood sampling is desired.

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Objective: Anatomical repositioning and expansion of the ipsilateral preserved lung after lung resection may influence postoperative pulmonary function. To study the postoperative changes in pulmonary function of the preserved lung after lobectomy compared with that after segmentectomy, the preoperative and postoperative forced expiratory volume in 1s (FEV(1)) of the ipsilateral non-operated lobe was measured using perfusion single-photon-emission computed tomography and computed tomography (SPECT/CT).

Methods: Eighty-nine patients (n=24; lobectomy, n=65; segmentectomy) who were examined with pulmonary function test and perfusion SPECT/CT both before and after surgery were enrolled in this study.

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Objective: The impact of segmentectomy for preservation of pulmonary function was quantified by using a co-registered perfusion single-photon-emission computed tomography and multidetector computed tomography (SPECT/CT).

Methods: Pulmonary function tests and perfusion SPECT/CT were conducted before and after segmentectomy in 56 patients. Actual values of forced expiratory volume in 1 second (FEV(1)) after segmentectomy were compared with the FEV(1) after virtual lobectomy, which was calculated by SPECT/CT.

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