Biomedical subjects

I Narabayashi

Publications and source records attributed to I Narabayashi.

121 records · Page 7Linked to original sources

PubMedDate not supplied

Intraarterial infusion chemotherapy with lipiodol-CDDP suspension for hepatocellular carcinoma.

PURPOSE: To quantitatively evaluate the usefulness of lipiodol-CDDP suspension (LCS) chemotherapy in hepatocellular carcinoma (HCC). METHODS: CDDP (cis-diamminedichloroplatinum) powder was prepared by removing the water and NaCl from aqueous CDDP. Two quantities of prepared CDDP powder, 10 mg and 20 mg, were mixed with 1 ml each of iopamidol 300 mgI/ml (IP300) and lipiodol (LPD) using a high pressure pumping method, thus producing LCS. Thirty-two patients with HCC, who had good renal function [creatinine clearance (Ccr) 50 ml/min or more], received additional intraarterial infusion chemotherapy with LCS or LCS alone. RESULTS: The most frequently observed CDDP powder sizes were 5.95-10.90 microm (average: 11.59 microm). The LCS obtained demonstrated a suspension of 2-12 microm (average 3.69 microm) immediately after mixing, and no significant changes were observed in LCS particle sizes 3 hr after mixing. Moreover, the sustained release with LCS was observed for up to 3 hr. Meanwhile, the peripheral free platinum concentration between intraarterial infusion chemotherapy with LCS and intraarterial infusion with the aqueous solution of CDDP, with respect to variance residence time (VRT), showed a significant difference, with a p value of 0.0382. The survival rate was 89.84% at 1 year, 73.78% at 2 years, and 68.51% at 3 years. Furthermore, the platinum concentration in the tumor was 25-95 times the concentration in the surrounding liver parenchyma. CONCLUSION: Good clinical results can be expected by applying LCS to HCC.

Antineoplastic Agents↗

PubMedDate not supplied

Three-dimensional CT angiography of the splenic-portal venous system by using multiple threshold display.

We assessed the three-dimensional (3D) CT angiographic reconstruction of the splenic-portal venous system obtained by using multiple threshold display (MTD) in 40 patients with liver disease. In each patient, both shaded surface display(SSD) and MTD images were generated by using an Xtension with a Sun SPARCstation 20, and they were compared by two radiologists. MTD image quality was superior to that of SSD images, because MTD diminished longitudinal direction artifacts and the image depicted the small vessels clearly. Based on the above results, we consider MTD to be a useful method for 3D-CT angiography of the splenic-portal venous system.

Angiography↗

PubMedDate not supplied

Optimal scan delay of arterial phase scanning of hepatic CT using a real-time image reconstruction system.

To optimize scan delay of arterial phase scanning of hepatic CT, 30 patients suspected of having HCC were examined using real-time image reconstruction technology (SureStart). In all cases, SureStart was successful. Despite the low dose, these images allowed adequate visualization of the abdominal aorta. The mean delay from the initiation of contrast administration to the beginning of arterial phase scanning was 29.6 +/- 5.2 sec (mean +/- SD; range, 22-51 sec).

Adult↗

PubMedDate not supplied

Helical CT of the liver with computer-assisted bolus-tracking technology: scan delay of arterial phase scanning and effect of flow rates.

PURPOSE: The purpose of this work was to assess the scan delay and the effect of flow rates on arterial phase scanning of hepatic CT. METHOD: One hundred twenty patients suspected of having hepatocellular carcinoma were examined by three-phase helical CT using computer-assisted bolus-tracking technology. We set the region of interest (ROI) in the abdominal aorta at the level of the celiac artery as a baseline. The triggering threshold was set at 100 HU. A volume of 100 ml of iomeprol (350 mg of I/ml) was administered at 2, 2.5, or 3 ml/s i.v. RESULTS: In all cases, helical CT scanning began after reaching the ROI threshold. Then, portal venous phase scanning was initiated 50 s after arterial phase initiation. The mean delay time from the initiation of contrast agent administration to the beginning of arterial phase scanning was 29.2 +/- 3.8 s (mean +/- SD, range 22-39 s). A faster injection rate significantly shortened the scan delay (p < 0.01). In portal venous phase scanning, calculated areas under the hepatic enhancement curves were almost equal among different injection rates. CONCLUSION: The computer-assisted bolus-tracking technology is a useful method for determining an individual scan delay of arterial phase CT.

Aged↗

PubMedDate not supplied

Three-dimensional imaging of laryngeal cancers using high-speed helical CT scanning.

To evaluate the clinical usefulness and limitations of three-dimensional (3-D) imaging of laryngeal cancers by high-speed helical (spiral) CT scanning, 3-D images were reconstructed for one dissected human larynx and 10 patients with laryngeal cancer. The larynges were scanned in 1- to 2-mm slices, and were reconstructed using a slice thickness of 0.5-1.0 mm. The macroscopic (or endoscopic) findings and the 3-D CT images of the larynx were compared. The selected threshold CT values were -600 HU (Hounsfield units) to -100 HU for the mucous membranes, and 250 HU for bone. Under these conditions, almost all of the structures remained distinct. The 3-D images of the larynx obtained by helical CT were very helpful in understanding laryngeal anatomy, especially in the subglottic area, which cannot be seen clearly by endoscopy or conventional axial CT. Clinically, this system would have advantages in the detection of subglottic cancers, or the invasion of glottic or supraglottic cancers into the subglottic area.

Adult↗

PubMedDate not supplied

Stereoscopic display of a three-dimensional image of the larynx using high-speed helical scanning.

To evaluate the usefulness of stereoscopic images of larynges using helical CT in stereo mode, a retrospective review of the characteristics of stereoscopic viewing of larynges was made. The subjects were 3 patients with laryngeal cancer, 1 patient with laryngeal leiomyosarcoma and 1 patient with an advanced tongue carcinoma whose formalin-fixed larynx was extirpated. The larynges were scanned by high-speed helical CT using 1- to 2-mm slices. The reproduction of stereographic images was performed by the manipulation and rotation of three-dimensional structures around the y-axis on the computer display. The three-dimensional images of the complex structures, such as the arytenoid cartilage, aryepiglottic fold and pyriform sinus, were better observed by binocular images (stereograms) than by monocular images. Stereoscopic views of the larynx are useful in producing three-dimensional images of the unseen inner surface of the human body.

Adult↗

PubMedDate not supplied

Three-dimensional computed tomographic angiography of pulmonary vessels.

OBJECTIVE: To assess the image quality of multiple threshold display (MTD) as a new technique for generating three-dimensional (3D) pulmonary computed tomographic (CT) angiographic images. METHODS: We used MTD, a type of shaded surface display (SSD) offering the selection of multiple thresholds and transparencies, to reconstruct 3D-CT angiograms from enhanced helical CT data sets in 33 patients with lung disease. In MTD, eight thresholds of CT values are selected, and transparency is assigned to each. The selected voxels, ranging from -600 to 1,000 Hounsfield Units, were divided into eight classes, and transparency ranging from 0 to 100% was assigned to each. The CT scanner employed was a Toshiba Xvigor. MTD and SSD images were generated by using an Xtension with a Sun SPARC station 20, and they were compared by two radiologists. RESULTS: The image quality of MTD images was superior to that of SSD images (p < 0.01), because the MTD images demonstrated clearly both the major and small vessels. CONCLUSION: MTD is a useful technique for 3D pulmonary CT angiography.

Female↗

PubMedDate not supplied

Multifocal primary lymphoma of bone: scintigraphy and MR findings before and after treatment.

A case of multifocal primary lymphoma of bone is reviewed. Ga-67 citrate, Tc-99m HMDP, and Tl-201 scintigraphs all showed multifocal radiotracer accumulation. CT showed subtle osteolytic and osteosclerotic changes with surrounding soft tissue density mass. MRI clearly showed abnormal signal intensity in the bone marrow. After systemic chemotherapy and infield radiotherapy, the patient showed clinically complete remission. MRI showed reduction of the extraosseous components, but there was little signal change in the bone marrow despite the clinical response to the therapy. Scintigrams were more useful than MRI and CT for both staging and assessing the early response to therapy. The soluble interleukin-2 receptor level was found to be related to tumor cell activity.

Adult↗

PubMedDate not supplied

Three-dimensional display of the bronchi using helical CT.

The purpose of this study was to evaluate the clinical usefulness of three-dimensional (3D) images of the bronchi obtained using helical CT. Thirteen patients with lung cancer, one with tracheal diverticulum, and one with bronchial amyloidosis were examined. The CT scanner employed was the Toshiba Xforce. The helical CT scan cycle consisted of 20 continuous rotations, each requiring 1.5 sec, for a total scanning time of 30 sec. Scans were obtained using a 5-mm X-ray beam width, a 5-mm/1.5 sec couchtop sliding speed, and a 2-mm reconstruction interval. 3D images were reconstructed using a CEMAX VIPstation. The optimal lower and upper threshold CT values for 3D images of the bronchi were -650 and -100 HU, respectively, and 3D images clearly depicted endobronchial lesions. Cartilage crescents were also demonstrated, but longitudinal and circular mucosal folds could not be visualized. In conclusion, 3D images of the bronchi acquired using helical CT were useful in evaluating endobronchial lesions.

Adult↗

PubMedDate not supplied

Helical scanning CT for hepatocellular carcinoma.

To evaluate the clinical usefulness of helical scanning CT for hepatocellular carcinoma, 39 patients were examined using a Toshiba CT system, the Xforce. Helical scanning CT data were acquired using up to 20 continuous 1.5-sec rotations, with contrast medium bolus injection of 100-150 ml at a rate of 1.5-3 ml/sec, and during a single breath-hold. Scanning was begun 35 to 50 sec after the start of injection. Helical scanning CT permits axial images to be reconstructed at any desired position within the scanned area, and provides images without interslice gaps caused by respiratory movement. Contrast enhanced helical scanning CT permits blood vessels to be clearly displayed following the bolus injection of contrast medium using an automatic injector. Furthermore, the shorter scanning time makes it possible to scan the target area in the desired vascular phase. In all 39 patients who were examined using contrast enhanced helical scanning CT, high-quality three-dimensional images were obtained. Such images were particularly useful for assessing the three-dimensional relationships among high density tumors and vascular structures. In conclusion, helical scanning CT was considered to be useful for hepatocellular carcinoma.

Aged↗

PubMedDate not supplied

Three-dimensional display of pulmonary nodules using helical CT.

To evaluate the clinical usefulness of three-dimensional (3D) images of pulmonary nodules acquired using helical CT, 3D reconstructions were performed in 32 patients using a CEMAX VIPstation. The CT scanner employed was the Toshiba Xforce. Helical CT data were acquired using up to 20 continuous 1.5-sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 mm/1.5 sec. Axial images were reconstructed at a section interval of 2 mm. The optimal lower and upper threshold CT values for 3D images were as follows: 1) solid pulmonary nodule (-700--400/-100 HU), 2) tumor invading pleura or chest wall (-700--400/-200 HU), 3) pulmonary nodule with cavity (-700--400/50 HU), 4) small pulmonary nodule (< 10 mm) (-750--650/-100 HU), and 5) arteriovenous malformation (180/500 HU). In all cases, it was possible not only to demonstrate abnormal findings three-dimensionally but also to grasp anatomical relationships among the pulmonary nodule, bronchi, vessels, and chest wall.

Adult↗

PubMedDate not supplied

Two adult cases of primary small bowel volvulus: usefulness of computed tomographic diagnosis.

Small bowel volvulus is usually secondary to conditions such as malrotation, congenital bands, postoperative adhesions, and internal hernias. Primary small bowel volvulus in an adult is rare, and only 14 cases had been reported in Japan as of 1994. Preoperative diagnosis is difficult, because clinical examinations and plain films are of limited diagnostic value. In our cases, CT showed signs of small bowel volvulus such as a U-shaped configuration or radial distribution of distended and fluid-filled loops of the small bowel converging toward the point of torsion, tightly twisted mesentery around the point of torsion (whirl sign), fusiform tapering loop (triangular sign in the cross section or beak sign in the longitudinal section), and signs of bowel ischemia or infarct such as attached mesenteric fluid and blurred mesenteric folds. CT enabled us to diagnose not only small bowel volvulus but also bowel ischemia or infarct.

Female↗

PubMedDate not supplied

In vitro uptake and release of TI-201 and Tc-99m MIBI in cultured tumor cells and effect of anticancer drug.

201Tl is useful in the diagnosis of tumor malignancy determined by the grade of washout rate to normal tissue, especially in lung tumors and thyroid tumors. 99mTc-MIBI, a tracer of myocardial blood flow, is also a tumor tracer. We examined whether the growth of tumor cells is related to the uptake and release of these tracers in cultured tumor cells. Cultured tumor cells (HeLa cells and squamous cell carcinomas derived from human lung cancer) were incubated for 60 min with 10 kBq of either tracer for the kinetic study of cellular uptake. They were additionally incubated for 90 min with cold medium for the kinetic study of cellular release. These cells cultured with various concentrations of actinomycin D (ACD) or CDDP were used to examine the correlation between the cellular growth and kinetics of these tracers. The cellular release of 201Tl increased relative to the concentration of added ACD or CDDP in both cell types. In contrast, the cellular release of 99mTc-MIBI was not changed by the addition of ACD in HeLa cells. In conclusion, 201Tl showed a slower washout rate in high-growth tumor cells than in low-growth tumor cells; thus, it could act as an indicator of tumor malignancy by assessing its washout rate.

Antineoplastic Agents↗