Norihiko Yoshimura

Hepatic perfusion abnormalities during treatment with hepatic arterial infusion chemotherapy: Value of CT arteriography using an implantable port system

PURPOSE The purpose of this study was to evaluate CT arteriography (CTA) using an implantable port system in the detection of perfusion abnormalities occurring during hepatic arterial infusion chemotherapy (HAIC). METHOD In 51 patients with unresectable primary and metastatic liver tumors, who had implanted port systems for HAIC, CTA examinations through the infusion pump were performed. When perfusion abnormalities were found, selective angiography and/or digital subtraction angiography using the implantable port system were performed to determine the etiology. RESULTS Forty-nine perfusion abnormalities were detected in 32 patients. Intrahepatic hypoperfusion was found in 24 cases. Of 11 patients in whom correction of the hypoperfusion was attempted, it was successful in 10. Of 13 patients in whom correction was not attempted, 6 patients showed progressive disease in nonperfused areas. Intrahepatic hyperperfusion was found in 14 cases, which showed no subsequent complication. Extrahepatic perfusion was found in 11 cases. CONCLUSION We consider CTA to be useful in detecting perfusion abnormalities that may compromise HAIC.

Coronary artery anomalies with a shunt : Evaluation with electron-beam CT

PURPOSE Our goal was to evaluate the role of electron-beam CT (EBT) in the diagnosis of patients with coronary artery anomalies with a shunt. METHOD We performed EBT in seven patients with coronary artery anomalies with a shunt. Four cases were coronary artery fistula (CAF) and three were an anomalous origin of the left coronary artery from the pulmonary artery (ALCA from PA). Serial single volume mode scanning was performed at end-diastole to evaluate the anatomical course of the anomalous coronary arteries. Cine mode scanning was done in all but one to examine the ventricular wall motion and volumetrics. RESULTS EBT could detect the course and drainage sites of all CAFs and ALCAs from PA. Cine mode scanning revealed reduced wall motion in one case with CAF and two cases with ALCA from PA. CONCLUSION EBT serves a useful role in the assessment of coronary artery anomalies with a shunt.

Measuring Noncalcified Coronary Atherosclerotic Plaque Using Voxel Analysis with MDCT Angiography: A Pilot Clinical Study

OBJECTIVE The purpose of our study was to evaluate a new method using voxel analysis for quantifying noncalcified plaque in coronary arteries using MDCT angiography (MDCTA) compared with luminal stenosis by catheter coronary arteriography. MATERIALS AND METHODS Forty-one normal and eight abnormal arterial cross sections with noncalcified plaque selected from 40 patients undergoing MDCTA were analyzed for percentage of stenosis and plaque volume using a voxel analysis technique. RESULTS Using voxel analysis, the normal arterial wall thickness was determined to be 0.8 +/- 0.4 mm. Attenuation values (in Hounsfield units) for normal segments ranged between 30 and 175 H and for abnormal (plaque-containing) segments ranged from -49 to 139 H (p < 0.05). Plaque volume measurements varied from 0.90 to 156 mm(3) with good interobserver correlation (R(2) = 0.9671). Percentage of stenosis correlated with quantitative coronary arteriography measurement (R(2) = 0.55). Voxel analysis underestimated the percentage of stenosis (Pearsons correlation coefficient, 1.2; p = 0.03). CONCLUSION The study shows that the voxel analysis technique appears to be an accurate and reproducible method to measure arterial wall thickness, noncalcified plaque, and degree of arterial stenosis using density values measured in Hounsfield units. The technique may be useful on further correlative studies.

3-Dimensional adaptive raw-data filter: Evaluation in low dose chest multidetector-row computed tomography

Objectives: To evaluate a 3-dimensional adaptive raw-data filter in reducing streak artifacts in low dose chest computed tomographic (CT) images. Methods: Fourteen adult patients who underwent low dose chest CT examination (parameters: 25 or 50 mAs, 120 kV) on 64-detector CTscanner were included in this study. We prepared 2 sets of contiguous 5-mm thick images by reconstruction with and without 3-dimensional adaptive raw-data filter (filter-processed and unprocessed images). Streak artifacts and visualization of peripheral vessels in both filter-processed and unprocessed images were evaluated using a 5-point scale. Upper, middle, and lower thorax were evaluated separately. Results: The difference in artifact severity was statistically significant in upper and lower thorax (P = 0.002 and 0.03, respectively), whereas it was not significant in middle thorax (P = 0.13). The difference in the visibility of peripheral pulmonary vessels was not statistically significant in all anatomical regions. Conclusions: The 3-dimensional adaptive raw-data filter reduced streak artifacts in low dose chest CT in upper and lower thorax.

Measuring Noncalcified Coronary Atherosclerotic Plaque Using Voxel Analysis with MDCT Angiography: Phantom Validation

OBJECTIVE This purpose of this study was to evaluate the accuracy and reproducibility of a voxel analysis technique for measuring noncalcified plaque in the coronary arteries. MATERIALS AND METHODS Polyethylene phantoms representing noncalcified plaque were scanned in both MDCT and micro-CT scanners and inter- and intrareader variability of volume calculation was performed. RESULTS Volume measurements by both MDCT and micro-CT were comparable to the true volume as measured by micrometry (< 3%, p = 0.05). CONCLUSION There appears to be no significant difference (< 3%) between MDCT and micro-CT measurements.

Noninvasive Imaging of Anomalous Origin of the Left Coronary Artery From the Pulmonary Artery

Electron beam computerized tomography (EBCT) during intravenous administration of contrast medium showed an anomalous origin of the left coronary artery from the pulmonary artery, sometimes known as the Bland-White-Garland syndrome. This 28-year-old woman presented with chest pain caused by progressive myocardial ischemia. In this case, a right coronary arteriogram confirmed …

MR arteriography using an implantable port system: a new method in assessing perfusion abnormalities during hepatic arterial infusion chemotherapy.

We present a case in which MR arteriography (MRA) with an indwelling catheter was used in a perfusion study of intrahepatic arterial chemotherapy for liver metastases. After embolization of collateral vessels using platinum coils, CT imaging was disturbed by strong artifact. However, platinum coils produced no MR artifact. In addition, MRA had greater advantages in depicting perfusion defects than perfusion scintigraphy. We consider MRA useful in assessing perfusion abnormalities during intrahepatic arterial chemotherapy.

Management for Patients with De Novo or Recurrent Tumors in the Residual Kidney after Surgery for Nonfamilial Bilateral Renal Cell Carcinoma

The tumor de novo in the residual kidney after surgery for nonfamilial bilateral renal cell carcinoma (RCC) is problematic. We reviewed 5 patients who experienced such a situation. Three patients had had metachronous bilateral RCC, treated with radical nephrectomy in one kidney and nephron-sparing surgery (NSS) in the other. Two patients had had synchronous disease; one patient had received radical nephrectomy and NSS, and the other bilateral NSS. The 5 patients had another solid mass/de novo tumor in the residual kidney 16–88 (mean 46.8) months after surgery. For the tumor de novo in earlier years (1992–1999), one patient underwent surgery and hemodialysis, and the other selected a conservative observation. In recent years (2000–2007), one patient was conservatively observed; the remaining 2 received computerized-tomography-guided radiofrequency ablation, and the local tumors were well controlled postoperatively for 20 and 12 months with their renal function unimpaired. Ablative techniques can potentially strike a balance between oncological and nephrological outcomes in patients with sporadic multiple RCC, successful management of which was difficult previously.