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Biomedical subjects

Tsunehiko Nishimura

Publications and source records attributed to Tsunehiko Nishimura.

At least 73 records · Page 4Linked to original sources
PubMed2004

Interventional radiologic treatment for hepatic arterial occlusion after repeated hepatic arterial infusion chemotherapy via implanted port-catheter system.

The present study evaluated the feasibility of interventional radiologic treatments for hepatic arterial occlusion after hepatic arterial infusion chemotherapy (HAIC) via an implanted port-catheter system. Treatment for hepatic arterial occlusion was attempted in seven patients with unresectable liver cancer. In six, the obstructed hepatic artery was recanalized. In three patients, the recanalized hepatic artery again became obstructed. However, by performing additional interventional radiologic procedures, secondary patency of the hepatic artery was successfully obtained in two patients. In conclusion, when hepatic arterial occlusion occurs, HAIC can be resumed in the attempt to recanalize the hepatic artery.

Adult↗
PubMed2004

Percutaneous needle biopsy for small lung nodules beneath the rib under CT scan fluoroscopic guidance with gantry tilt.

OBJECTIVES: The present study was performed to evaluate the efficacy and safety of gantry tilting for the performance of lung biopsy of peripheral small lesions located beneath the rib. DESIGN: Interventional. MATERIALS AND METHODS: Our study was based on 22 of 237 lesions for which percutaneous needle biopsies of the lung were performed under CT scan-fluoroscopic guidance at our institution between January 2000 and August 2002. For these 22 lesions, a biopsy was performed with gantry tilt because a rib blocked the biopsy route even after trials to change the relationship between the target and the rib. The characteristics of each lesion, the success rate for obtaining an adequate specimen, and the ability to determine whether the lesion was malignant or benign were investigated, specific cell types were characterized, and the complications that were encountered were identified. RESULTS: In all 22 lesions, adequate specimens for cytopathologic evaluation were obtained using fine-needle aspiration biopsy, tissue core biopsies, or both. In 21 lesions, whether the lesion was malignant or benign was precisely diagnosed, and in 19 lesions the specific cell type was determined. No serious complications occurred. CONCLUSION: Percutaneous needle biopsy under CT scan-fluoroscopic guidance with gantry tilt is a useful and safe technique for the biopsy of small lung nodules located beneath the rib.

Biopsy, Needle↗
PubMed2004

[Diagnosis of coronary artery disease by thallium-201 myocardial scintigraphy with intravenous infusion of SUNY4001 (adenosine) in effort angina pectoris--the clinical trial report at multi-center: phase II].

Forty-four patients with effort angina pectoris were evaluated with SUNY4001 (adenosine) thallium-201 (201Tl) myocardial scintigraphy to detect coronary artery disease. These patients had single-vessel disease (> or = AHA 90% stenosis) in either RCA or LAD. Adenosine was infused at the rate of 120 or 140 microg/kg/min for six minutes. 111 MBq of 201Tl was injected after three minutes of the start of the infusion. The early and delayed images were obtained by SPECT imaging. The sensitivity was 94.7% at 120 microg/kg/min and 84.2% at 140 microg/kg/min. Adenosine 201Tl myocardial scintigraphy showed high accuracy for detecting significant coronary artery disease. Adverse reactions occurred in 77.3% of the patients. Regarding the rates of the adverse reactions, there was no significant difference between 120 and 140 microg/kg/min. Major adverse reactions were Chest pain/discomfort (52.3%) and Flushing/Feeling of warmth (27.3%). No serious complication was observed at any infusion rate. Most of adverse reactions disappeared sortly. Only two patients required treatment for moderate chest pain, which, however, disappeared in several minutes. One of the treatments was merely the termination of adenosine infusion, and the other was sublingual spray of nitroglycerin. Adenosine infusion caused slight decrease in blood pressure and increase in heart rate. The hemodynamic changes resolved within several minutes after the adenosine infusion. Decrease in systolic blood pressure of more than 20 mmHg from the base level occurred in 26.1% and 52.4% at 120 and 140 microg/kg/min infusion rate respectively. Therefore, the adenosine infusion at 120 microg/kg/min should be considered safe and useful for the diagnosis of coronary artery disease by pharmacologic stress imaging.

Adenosine↗
PubMed2004

[The diagnostic value for ischemic heart disease of thallium-201 myocardial scintigraphy by intravenous infusion of SUNY4001 (adenosine)--the report of clinical trial at multi-center: phase III].

With two hundred and seven patients unable to exercise adequately, the diagnostic accuracy and adverse reaction of 201Tl myocardial scintigraphy with the pharmacologic stress by SUNY4001 (adenosine) infusion were studied. Adenosine was infused for six minutes at the rate of 120 microg/kg/min, and then 201Tl was injected after three minutes from the start of infusion. The early and delayed images were obtained by SPECT imaging. According to angiography, > or = AHA 90% stenosis was defined as significant. The sensitivity of detecting coronary artery disease was 87.1% and the specificity was 46.0%. Adverse reactions occurred in 66.7% of the patients, most of which disappeared shortly with no need for treatment. Major adverse reactions were chest pain/discomfort (30.4%), flushing/feeling of warmth (22.4%) and blood pressure decrease (17.4%). Adenosine infusion caused slight decrease in blood pressure and increase in heart rate. These hemodynamic changes were resolved within several minutes from the termination of adenosine infusion. We concluded that adenosine-201Tl imaging is safe and useful to detect coronary artery disease in patients unable to exercise adequately.

Adenosine↗
PubMed2004

[Comparison of myocardial perfusion imaging by thallium-201 single-photon emission computed tomography with SUNY4001 (adenosine) and exercise--crossover clinical trial at multi-center].

We compared the ischemic diagnosis ability and adverse events of 201Tl myocardial perfusion imaging with SUNY4001 (adenosine) stress to that with exercise (ergometer) stress both on random crossover trial. Thirty one known or suspected chronic stable angina patients who are able to exercise and 10 healthy volunteers were enrolled for the trial. The early and delayed images were obtained by SPECT imaging. The concordance of diagnoses [ischemia vs. no ischemia] between the two types of stresses was 97.3% (36/37) [Kappa: 0.9068]. The sensitivity and specificity based on the exercise test were 100% (6/6) and 96.8% (30/31) respectively. The incidence of adverse events caused by SUNY4001 and the exercise were 44.7% (17/38) and 52.6% (20/38), respectively. Major adverse events caused by SUNY4001 were BP decrease, flushing and headache. And those by exercise were ST decrease, dyspnea and chest pain. None of the adverse events required the intervention or caused life-threatening complication in the trial. The trial showed that the ischemic diagnosis ability and safety of 201Tl scintigraphy with SUNY4001 stress are almost equal to those of the exercise stress that is considered as the standard stress method. We concluded that 201Tl imaging with SUNY4001 is safe and useful for detecting ischemic heart disease, especially for patients unable to exercise adequately.

Adenosine↗
PubMed2003

Assessment of left ventricular diastolic function by gated single-photon emission tomography: comparison with Doppler echocardiography.

Gated single-photon emission tomography (SPET) is not yet an established procedure for the evaluation of left ventricular (LV) diastolic function. This study examined diastolic function derived from gated SPET in comparison with an established diagnostic tool, Doppler echocardiography. We examined 37 consecutive patients with normal sinus rhythm who underwent gated technetium-99m tetrofosmin SPET. A gated SPET program was used with a temporal resolution of 32 frames per R-R interval. We obtained the Doppler transmitral flow velocity waveform immediately before gated SPET image acquisition. Patients who showed a ratio of peak early transmitral flow velocity to atrial flow velocity (E/A) of >1 or whose R-R intervals differed by >5% between Doppler echocardiography and gated SPET were excluded from this investigation. We compared diastolic indices and presumed corresponding intervals in diastole using the two methods. The peak filling rate (PFR) derived from gated SPET correlated with the Doppler peak velocity of the early transmitral flow (E) wave ( r=0.65) and deceleration of the E wave ( r=0.71). The time to PFR and percent atrial contribution to LV filling from gated SPET correlated excellently with the Doppler LV isovolumic relaxation time ( r=0.93) and the E/A ratio ( r=-0.85), respectively. There was a significant linear correlation in all the intervals from the R wave to the presumed corresponding diastolic points. The point of PFR in gated SPET and the peak of the E wave in Doppler echocardiography generally coincided. The onset of filling in gated SPET tended to be closer to the second heart sound than the start of the E wave in Doppler echocardiography. We conclude that gated SPET permits the assessment of not only myocardial perfusion and LV systolic function but also diastolic function, although there may be some errors in detection of the precise beginning of LV filling.

Adult↗
PubMed2003

Fiber-tracking method reveals sensorimotor pathway involvement in stroke patients.

BACKGROUND AND PURPOSE: We tested the feasibility of a new MRI technique that provides visualization of the sensorimotor tracts in vivo in a group of stroke victims. SUMMARY OF REPORT: Fourteen patients with small infarctions involving the white matter of the supratentorial brain were evaluated. Sensorimotor tracts on the lesional and contralesional sides were successfully depicted in all cases. The position of the sensorimotor tracts relative to the infarct was in good agreement with clinical symptoms. The overall sensitivity and specificity for sensorimotor tract involvement were 100% and 77%, respectively. CONCLUSIONS: Our proposed fiber-tracking method was shown to be a clinically feasible technique that correlates well with clinical symptoms.

Aged↗
PubMed2003

MR imaging-guided axillary node biopsy for breast cancer: initial findings.

The aim of this study was to evaluate the usefulness and feasibility of preoperative sentinel node needle biopsy of the breast under guidance of open MR imaging, a method that we developed. Nine patients with breast cancer in whom the axillary lymph nodes were not palpable underwent preoperative sentinel node needle biopsy under real-time MR imaging guidance. The sentinel nodes were identified before the biopsy using CT and MR imaging. Diagnostic ability of this method was compared with that of the operative diagnosis. Sentinel nodes were correctly identified in all 9 patients. The MR imaging-guided sentinel node needle biopsy was performed for all of the 9 patients, and, in 7 (77.8%) of the 9, a specimen sufficient for pathologic evaluation was obtained; and in 6, whether malignancy existed was precisely diagnosed. No serious complications were noted. This experience indicates the possibility of a precise diagnosis of whether the sentinel node in breast cancer is benign or malignant without surgery.

Adult↗
PubMed2003

Left ventricular mass index measured by quantitative gated myocardial SPECT with 99mTc-tetrofosmin: a comparison with echocardiography.

OBJECTIVE: Left ventricular mass is an important determinant of diagnosis and prognosis in patients with heart disease. The aim of the present study was to validate measurement of the left ventricular mass index (LVMI) by quantitative gated myocardial SPECT (QGS) with 99mTc-tetrofosmin by comparing it with echocardiography. METHODS: QGS and M-mode echocardiography (Echo) were performed within one month of each other in 179 patients. M-mode echocardiography was carried out according to Devereux's method. QGS images were acquired one hour after injection of 99Tc-tetrofosmin at rest. Myocardial volume was defined as the volume between the endocardial and epicardial surface in the end-diastolic phase. LVMI (g/m2) was defined as myocardial volume divided by myocardial specific density and corrected for body surface area. QGS LVMI measurements were performed twice by the same observer and independently by two different observers. Regional hypoperfusion in the group of patients with old myocardial infarction (n = 26) was evaluated semiquantitatively on the basis of the total defect score on the resting 99mTc-tetrofosmin SPECT images. RESULTS: Among the patients as a whole QGS LVMI was significantly correlated with Echo LVMI (r = 0.96, p < 0.001). Intra-observer and inter-observer analyses showed significant reproducibility (r = 0.99 and r = 0.98, respectively, p < 0.001). In the patients with old myocardial infarction, but QGS LVMI was significantly lower than Echo LVMI (p < 0.001), and the magnitude of the underestimation was closely related to the severity of the perfusion defect on the resting SPECT images. CONCLUSIONS: Measurements of LVMI by 99mTc-tetrofosmin QGS are reproducible and consistent with echocardiograpic estimates. Underestimation in patients with severe perfusion defects must be taken into consideration.

Echocardiography↗
PubMed2003

Optimization of TI values in inversion-recovery MR sequences for the depiction of fine structures within gray and white matter: separation of globus pallidus interna and externa.

RATIONALE AND OBJECTIVES: The authors' purpose was to search the inversion time (TI) values that enable the best differentiation of fine structures in gray matter (gray-gray differentiation). MATERIALS AND METHODS: Seven healthy adult volunteers with no history of neurologic disease or head trauma were recruited and gave their informed consent. The subjects consisted of two men and five women ranging in age from 25 to 38 years, with a mean age of 28 years +/- 5. The subjects were imaged with a turbo spin-echo inversion-recovery sequence. This sequence was performed in the axial plane at the level of the basal ganglia with the following parameters: repetition time, 3,200 msec; echo time, 15 msec; three signals acquired; echo train, seven; section thickness, 3 mm; matrix size, 256 x 256; and field of view, 180 mm. The tested values were TI = 100, 200, 300, 400, and 500 msec. Region-of interest measurements were performed at the following anatomic structures and represent gray-gray and white-white differentiations, respectively: globus pallidus externa versus globus pallidus interna, and optic radiation versus surrounding white matter. RESULTS: The maximum contrast index value occurred at TI = 400 msec for globus pallidus externa versus globus pallidus interna (P < .05) With the contrast-to-noise ratio, no significant difference in gray-gray differentiation was observed among the various TIs. The minimum signal-to-noise ratio of the gray matter occurred at TI = 400 msec (P < .05). A subjective evaluation revealed an overall superiority of gray-matter differentiation with TI = 400 msec. CONCLUSION: A TI of 400 msec was the most suitable for this purpose.

Adult↗
PubMed2003

Transient aphasia as late-onset seizure after embolization for dural arteriovenous malformation.

Tc-99m HMPAO single photon emission computed tomography was performed in a patient who had experienced aphasia for 3 days. The patient had a medical history of subarachnoid hemorrhage and intracranial hemorrhage. Both of these hemorrhages were related to a dural arteriovenous malformation that was embolized after the onset of the cerebral vascular events. Focal hyperperfusion was seen in the left temporal lobe adjacent to a perfusion defect corresponding to the old cerebral hemorrhage. The finding was interpreted as the focus of the patient's epilepsy. His aphasia resolved after the administration of anticonvulsant medication for several days.

Aphasia↗
PubMed2003

Withdrawal of implanted port-catheter for hepatic arterial infusion chemotherapy with fixed catheter tip technique.

The purpose of the present study is to evaluate the feasibility of a method developed to withdraw a port-catheter system that had been implanted with use of the fixed catheter tip technique. Withdrawal of an implanted catheter was required in four patients with advanced liver cancer in whom port-catheter systems had been implanted for performance of repeated hepatic arterial infusion. In all patients, port-catheter systems were successfully removed without complications. In conclusion, an implanted port-catheter system can be removed even when implanted with the fixed catheter tip technique.

Aged↗
PubMed2003

Brain fiber tracking with clinically feasible diffusion-tensor MR imaging: initial experience.

Two technical challenges must be overcome before brain fiber tracking with diffusion-tensor magnetic resonance (MR) imaging can be applied to clinical practice: Imaging time must be shortened, and image distortion must be minimized. Single-shot echo-planar MR imaging with parallel imaging technique enabled both objectives to be accomplished. Twenty-three consecutive patients with brain tumors underwent MR imaging with a 1.5-T whole-body MR system. Fiber tracts on the lesion side in the brain had varying degrees of displacement or disruption as a result of the tumor. Tract disruption resulted from direct tumor involvement, compression on the tract, and vasogenic edema surrounding the tumor. This diffusion-tensor MR imaging method with the parallel imaging technique allows clinically feasible brain fiber tracking.

Adolescent↗
PubMed2003

Usefulness of new automated cutting needle for tissue-core biopsy of lung nodules under CT fluoroscopic guidance.

OBJECTIVES: The goal of our study was to evaluate the efficacy and safety of a new type of automated cutting needle for tissue-core lung biopsy under real-time CT fluoroscopic guidance. DESIGN: Observational MATERIALS AND METHODS: One hundred ten percutaneous needle tissue-core lung biopsies were performed with the Auto Surecut needle (Create Medic; Yokohama, Japan) under CT fluoroscopic guidance, and the specimens obtained underwent histopathologic evaluation. A final diagnosis was confirmed by independent surgical pathology. RESULTS: The rate of success for the diagnosis for specimens that were adequate for histopathologic analysis was 94.5% (104 of 110 specimens). The sensitivity, specificity, and accuracy in diagnosing malignancy were 95.1%, 100%, and 96.2%, respectively. A specific cell type could be characterized in 95.2% of those 104 lesions (99 lesions; malignant, 76 lesions; benign, 23 lesions). The specific cell type was precisely diagnosed, and was confirmed after surgery in 65 malignant lesions and 23 benign lesions. The biopsy-induced complications encountered were pneumothorax in 34.5% (38 of 110 patients) and hemoptysis in 6.4% (7 of 110 patients). No patient had a serious complication. CONCLUSION: CT fluoroscopy-guided lung biopsy using the Auto Surecut needle provides a high degree of diagnostic accuracy, allows for the specific characterization of lung nodules, and can be performed safely.

Aged↗
PubMed2003

Combining fine-needle aspiration and core biopsy under CT fluoroscopy guidance: a better way to treat patients with lung nodules?

OBJECTIVE: The goal of our study was to evaluate the efficacy of the combined use of fine-needle aspiration and tissue core biopsy under real-time CT fluoroscopy guidance. SUBJECTS AND METHODS: One hundred thirty-eight percutaneous needle lung biopsy samples were obtained by two methods. The samples obtained by tissue fine-needle aspiration underwent cytologic evaluation, and those obtained by core biopsy using an automated cutting needle underwent histologic evaluation. The final diagnosis was confirmed by independent surgical pathologic findings, independent culture results, or clinical follow-up. RESULTS: Rates of adequate specimens obtained and of precise diagnosis by combined use of fine-needle aspiration and core biopsy were 97.1% (134/138) and 94.2% (130/138) evaluated lung lesions, respectively, whereas those rates were 84.8% (117/138) and 79.7% (110/138) by fine-needle aspiration alone and 91.3% (126/138) and 89.1% (123/138) by core biopsy alone, respectively. Precise diagnosis was achieved by the combined use of the techniques in 30 (93.8%) of 32 lesions ranging from 3 to 10 mm in diameter, 42 (93.3%) of 45 lesions ranging from 11 to 20 mm, 43 (93.5%) of 46 lesions ranging from 21 to 30 mm, and 100% of 15 lesions ranging from 31 to 100 mm. In 89 of 90 lesions shown to be malignant by CT-guided lung biopsy and 30 of 44 shown to be benign, specific cell types could be proven from specimens obtained by the combined use of the two different types of needle biopsy. CONCLUSION: The combined use of fine-needle aspiration and core biopsy improves the diagnostic ability of CT fluoroscopy-guided lung biopsy, even in small lesions.

Adolescent↗
PubMed2003

Change in the hemodynamics of the portal venous system after retrograde transvenous balloon occlusion of a gastrorenal shunt.

OBJECTIVE: The purpose of our investigation was to examine changes in the hemodynamics of the liver after artificial occlusion of a gastrorenal shunt. SUBJECTS AND METHODS: Nine patients with portal hypertension underwent splenic arteriography and CT arterial portography during infusion of contrast material via the splenic artery. Images were obtained with the balloon catheter both inflated and deflated in the gastrorenal shunt, and results were compared. RESULTS: During the portal phase of splenic arteriography, the intrahepatic portal vein was more clearly seen when the balloon occluded the gastrorenal shunt. Mean CT attenuation values of branches of the intrahepatic portal vein on CT arterial portograms acquired when the balloon catheter was inflated were higher than values acquired when the balloon was deflated; however, results for the inferior vena cava were the opposite. Differences in CT attenuation values were statistically significant for the right branch of the portal vein, main portal vein, right lobe of the liver parenchyma, and inferior vena cava. CONCLUSION: Closure of large gastrorenal shunts (hepatofugal portasystemic shunts) causes the portal blood flow to switch from hepatofugal to hepatopetal, which increases the effective intrahepatic portal blood flow.

Aged↗
PubMed2003

[Intravascular ultrasound imaging of the renal artery in patients with renovascular hypertension caused by neurofibromatosis 1].

A 26-year-old woman with neurofibromatosis 1 was admitted to our hospital for investigation of prolonged hypertension after toxemia of pregnancy. Plasma renin activity was elevated. From the renogram, stenosis of right renal artery was suspected and we performed renal arteriography, which revealed proximal right renal artery stenosis. The intravascular ultrasound (IVUS) image showed concentric stenosis with intimal and medial hypertrophy, which was iso-echoic and partly high echoic. Percutaneous transluminal renal angioplasty was performed and the lesion was well dilated. After angioplasty, blood pressure normalized in a week. From the clinical course and the IVUS image, we suspected that renal artery stenosis was due to neurofibromatosis 1.

Adult↗