Biomedical subjects

Shuji Kariya

Publications and source records attributed to Shuji Kariya.

14 recordsLinked to original sources

PubMed2006

Percutaneous vertebroplasty: relationship between vertebral body bone marrow edema pattern on MR images and initial clinical response.

PURPOSE: To prospectively investigate the relationship between initial clinical response and bone marrow edema pattern on preprocedural magnetic resonance (MR) images in vertebral bodies selected for percutaneous vertebroplasty (PVP). MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. PVP was performed for osteoporotic compression fractures in 80 consecutive patients (mean age, 72.4 years; range, 44-85 years; 67 women and 14 men; 157 vertebrae). Patients were divided into three groups according to the proportion of the vertebra in which the bone marrow edema pattern was observed on sagittal MR images: group 1, 50% or more of the vertebra; group 2, less than 50%; group 3, no edema pattern observed. By using Wilcoxon rank sum test, Fisher exact test, and Wilcoxon signed rank test, groups were examined for differences in treatment efficacy, which was defined as the difference between preprocedural and postprocedural pain as assessed by means of visual analog scale (VAS) score at 1-3 days after PVP. RESULTS: Forty-four patients were assigned to group 1, 14 to group 2, and 22 to group 3. No significant difference was seen between the groups with respect to age, sex, number of treated vertebrae, or preprocedural VAS score. In group 1, VAS score decreased from 7.5 before the procedure to 2.9 after (improvement of 4.6). In group 2, the score decreased from 6.8 to 3.1 (improvement of 3.7). In group 3, the score decreased from 7.0 to 4.3 (improvement of 2.7). Improvement was significantly greater in group 1 than in group 3 (P < .005). CONCLUSION: PVP resulted in significantly greater clinical improvement in patients with an extensive bone marrow edema pattern than in those without this pattern. (c) RSNA, 2006.

Adult↗

PubMed2006

[Basic experimental study of intraosseous venography using carbon dioxide contrast agent in percutaneous vertebroplasty].

PURPOSE: In percutaneous vertebroplasty (PVP), intraosseous venography is performed using water-soluble ionic iodinated contrast media (iodine contrast media) before injecting bone cement. However, because of contrast medium remaining in the fractured cleft, we experienced the persistence of intravertebral opacification that obscured visualization of the cement under X-ray fluoroscopy. To solve this problem, we examined carbon dioxide (CO(2)) as a contrast medium. METHODS: We measured the contrast of iodine contrast media and CO(2) and performed a subjective assessment of imaging by enforcing intraosseous venography by changing the tube voltage and image intensifier (I.I.) entrance dose in a bone sample of a cadaver using iodine contrast media and CO(2). In vivo study, we performed a subjective assessment of images obtained by intraosseous venography using CO(2) under two kinds of X-ray views. RESULTS: We determined that the contrast of CO(2) is 1/6-1/7.5 that of iodine contrast media, and that CO(2) fluctuates less in its contrast value with changes in tube voltage. In our assessment of the image of the bone sample, CO(2) performed worse that iodine contrast media. However, if the I.I. entrance dose is kept above 2.5 microGy/F, CO(2) is considered to be of clinical use. In the clinical image assessment, the best conditions were an image collection rate of 7.5 F/S and matrix of 1024 x 1024. CONCLUSIONS: CO(2) did not cause any obstacles when we injected bone cement, and its I.I. entrance dose, image collection rate, and matrix size indicate that it can be used for intraosseous venography.

Bone Cements↗

PubMed2006

A case of spontaneous regression of hepatocellular carcinoma with multiple lung metastases.

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. We present herein the case of a patient with hepatocellular carcinoma with multiple lung metastases in whom malignancy spontaneously regressed after taking Pheliinus linteus Mycelium. A 79-year-old man consulted our hospital complaining of epigastric discomfort. Abdominal MRI and CT revealed a 3 cm diameter tumor in the liver, and chest CT showed numerous nodular lesions. The levels of alpha-fetoprotein (AFP) and protein induced by vitamin K deficiency or antagonist-II (PIVKA-II) were very high. We diagnosed HCC with multiple lung metastases, and no therapy was performed. Independently he took exact from Phellinus linteus Mycelium for one month, and 6 months later the tumors appeared to be in complete regression. The mechanism underlying this intriguing phenomenon remains unknown.

Aged↗

PubMed2005

Radiation exposure to operators during vertebroplasty.

PURPOSE: To measure the radiation received by physicians during percutaneous vertebroplasty with use of two types of injection devices with the interventional equipment guided by computed tomography (CT) and an angiographic/CT system. MATERIALS AND METHODS: Twenty consecutive patients who underwent percutaneous vertebroplasty were included in this study. The patients were divided into two groups, the 1-mL syringe group and the bone cement injector group. Percutaneous vertebroplasties were performed with the IVR-CT system, which combines angiographic and CT equipment with a single fluoroscopy table. Radiation dose to operators was measured as equivalent dose penetrating at a 10-mm tissue depth with use of electronic personal dosimeters attached outside and inside lead aprons. Effective radiation dose (HE) was estimated based on the radiation dose outside the lead apron (Ha) and the radiation dose inside the lead apron (Hb). Differences between the groups in doses and fluoroscopic duration were analyzed. RESULTS: In the 1-mL syringe group and bone cement injector group, mean Ha measurements were 320.8 microSv and 116.2 microSv, respectively. Mean Hb measurements were 14.5 microSv versus 7.8 microSv and mean HE measurements were 48.2 microSv versus 19.7 microSv. Significant differences were found in Ha, Hb, and HE. However, duration of fluoroscopy did not differ significantly between groups. CONCLUSIONS: Radiation dose was relatively high for operators performing percutaneous vertebroplasty. The bone cement injector was useful in reducing the level of radiation exposure to operators during vertebroplasty.

Fluoroscopy↗

PubMed2005

Radiofrequency ablation combined with CO2 injection for treatment of retroperitoneal tumor: protecting surrounding organs against thermal injury.

OBJECTIVE: The objective of this study was to separate target tumors from adjacent structures by injecting carbon dioxide (CO2) around the tumor to avoid thermal injury and the heat-sink effect from the blood vessel during percutaneous radiofrequency ablation. CONCLUSION: We successfully achieved complete ablation of a retroperitoneal tumor without thermal injury. Imaging-guided percutaneous CO2 injection is useful for preventing thermal injury while achieving complete ablation of the tumor during radiofrequency ablation.

Adrenal Gland Neoplasms↗

PubMed2005

Intraosseous venography with carbon dioxide contrast agent in percutaneous vertebroplasty.

OBJECTIVE: Our objectives were to ascertain whether CO2 can be used as a contrast agent in venography during percutaneous vertebroplasty and to evaluate whether it might be capable of replacing nonionic iodinated contrast agents. CONCLUSION: Intraosseous venography with CO2 contrast agent was slightly inferior to iodine venography in terms of its ability to visualize the vertebral bodies and perivertebral veins, but it remains a useful technique because no interference with optimal visualization of bone cement occurs during the cement injection when CO2 remains within the fracture cleft.

Aged↗

PubMed2005

Residual stenosis after conventional balloon angioplasty for hemodialysis shunt failure: treatment with metallic stent placement and post-balloon dilatation.

PURPOSE: The usefulness of metallic stent placement and post-balloon dilatation was investigated for patients with residual stenosis after conventional percutaneous transluminal balloon angioplasty (balloon PTA) of dialysis shunt vessels. MATERIALS AND METHODS: Among 92 patients who had received balloon PTA for dialysis shunt vessels, seven patients who showed a residual waist on the balloon even under maximum inflation were enrolled in this study. In these patients with residual stenosis after balloon PTA, we inserted a stent in the residual stenosis, and post-balloon dilatation was immediately applied using the same balloon catheter. RESULTS: After balloon PTA, the average percent diameter stenosis declined to 45.5 +/- 7.30%, and the stenosis was further improved to an average of 19.3 +/- 7.09% after the placement of a stent and the additional balloon PTA. The average percent diameter dilatation of the balloon before the placement of a stent was 65.8 +/- 12.7%, while the average dilatation increased to 84.1 +/- 8.96% after the placement of a stent. Dialysis became possible immediately after the procedure in all cases. CONCLUSION: Metallic stent placement and post-balloon dilatation was effective for patients with residual stenosis after conventional balloon PTA of dialysis shunt vessels.

Aged↗

PubMed2004

[CT].

The development of multidetector-row CT(MDCT), which can rapidly scan a large longitudinal volume and enables us to obtain thinner section collimation with a shorter acquisition time, obtained isotropic voxel data for three-dimensional(3D) imaging. Isotropic voxel data enables us to obtain sagittal and coronal images with the spatial resolution which is identical to axial images. Excellent volume data, which was acquired by MDCT, obtain serviceable 3D images by using various reconstruction methods, such as multi-planar reconstruction(MPR), maximum intensity projection(MIP), minimum intensity projection(MinIP), surface rendering, volume rendering and virtual endoscopy. However, relation between Ct and MRI is still complementary even in the times of MDCT.

Humans↗

PubMedDate not supplied

Stenting of the superior mesenteric artery as a preoperative treatment for total pancreatectomy.

The patient was 58-year-old male with mucinous cyst adenocarcinoma of the pancreas. Prior to total pancreatectomy, preoperative CT and angiography showed a high-grade arteriosclerotic stenosis of about 1.0 cm in length in the ostium of the superior mesenteric artery (SMA), as well as the development of collateral vessels in the area around the head of the pancreas. A stent was placed in the SMA stenosis to preserve intestinal blood flow in the SMA region after total pancreatectomy, which was performed 25 days after stent placement. The postoperative SMA blood flow was favorable, with no postoperative intestinal ischemia, and the patient had an uneventful postoperative course.

Blood Vessel Prosthesis Implantation↗

PubMedDate not supplied

Usefulness of CT during renal arteriography: a case of percutaneous radiofrequency ablation for renal cell carcinoma.

A 64-year-old man with a unilateral 15 mm diameter renal cell carcinoma underwent percutaneous radiofrequency ablation (RFA) assisted by CT during renal arteriography (angio-CT). Prior to placement of the needle electrode, a 5 Fr angio-catheter was placed in the right renal artery, and angio-CT was performed before, during and after the procedure. Since multiple angio-CT can be performed using a small amount of diluted contrast agent, RFA can be monitored without impairing renal function. As a result, this imaging combination was found to be useful for determining the end point of ablation.

Carcinoma, Renal Cell↗

PubMedDate not supplied

Radiological follow-up of new compression fractures following percutaneous vertebroplasty.

The purpose of the present study was to ascertain chronological changes in the analgesic effects of percutaneous vertebroplasty (PVP) on osteoporotic vertebral compression fractures and to radiologically follow new compression fractures after PVP. Seventy-six patients (206 vertebral bodies) were followed radiologically for a mean of 11.5 months. A visual analog scale (VAS; 0-10) was used to assess pain severity, and frontal and lateral plain radiographs of the thoracic and lumbar vertebrae were taken 1-3 days and 1, 4, 10, and 22 months after PVP. The average VAS score was 7.2 +/- 2.0 (mean pain score +/- standard deviation) before PVP, 2.5 +/- 2.3 at 1-3 days after PVP, 2.2 +/- 2.3 at 1 month, 1.9 +/- 2.2 at 4 months, 1.8 +/- 2.4 at 10 months, and 1.0 +/- 0.2 at 22 months. A new compression fracture was confirmed in 56 vertebral bodies in 28 patients (36.8%), affecting 38 adjacent vertebral bodies (67.8%), 17 nonadjacent vertebral bodies (30.4%), and 1 treated vertebral body (1.8%). A new compression fracture occurred within 1 week of PVP in 2 vertebral bodies (3.6%), between 1 week and 1 month after PVP in 22 (39.3%), between 1 and 3 months in 12 (21.4%), between 3 and 6 months in 12 (21.4%), and after more than 6 months in 8 (14.3%). PVP was highly effective in relieving the pain associated with osteoporosis-induced vertebral compression fractures, and this analgesia was long lasting. Radiological follow-up observation revealed new compression fractures in about one-third of patients. More than half of these new compression fractures occurred in adjacent vertebral bodies within 3 months of PVP.

Contrast Media↗

PubMedDate not supplied

Percutaneous vertebroplasty for osteoporotic compression fracture: multivariate study of predictors of new vertebral body fracture.

PURPOSE: To investigate the risk factors and relative risk of new compression fractures following vertebroplasty. METHODS: Initially, we enrolled 104 consecutive patients with vertebral compression fractures caused by osteoporosis. A total of 83 of the 104 patients visited our hospital for follow-up examinations for more than 4 weeks after vertebroplasty. Logistic regression analysis of the data obtained from these 83 patients was used to determine relative risks of recurrent compression fractures, using 13 different factors. RESULTS: We identified 59 new fractures in 30 of the 83 patients: 41 new fractures in vertebrae adjacent to treated vertebrae; and 18 new fractures in vertebrae not adjacent to treated vertebrae. New fractures occurred in vertebrae adjacent to treated vertebrae significantly more frequently than in vertebrae not adjacent to treated vertebrae. Only cement leakage into the disk was a significant predictor of new vertebral body fracture after vertebroplasty (odds ratio = 4.633). None of the following covariates were associated with increased risk of new fracture: age, gender, bone mineral density, the number of vertebroplasty procedures, the number of vertebrae treated per procedure, the cumulative number of vertebrae treated, the presence of a single untreated vertebra between treated vertebrae, the presence of multiple untreated vertebrae between treated vertebrae, the amount of bone cement injected per procedure, the cumulative amount of bone cement injected, cement leakage into the soft tissue around the vertebra, and cement leakage into the vein.

Aged, 80 and over↗

PubMedDate not supplied

Clinical assessment of percutaneous radiofrequency ablation for painful metastatic bone tumors.

PURPOSE: To investigate the pain-alleviating effects of radiofrequency ablation (RFA) on metastatic bone tumors in relation to tumor size, combined therapy, and percent tumor necrosis rate following RFA. METHODS: Subjects comprised 24 patients with 28 painful metastatic bone tumors. A 17G internally cooled electrode was inserted into the tumor for CT guidance and ablation was performed. Bone cement was injected following RFA for 4 tumors involving a weight-bearing bone, while 5 tumors were treated using combined RFA and external irradiation. Percent necrosis rate of the tumor was measured using contrast-enhanced computed tomography 1 week after RFA. RESULTS: Improvement in the visual analog scale (VAS) score was 4.6 +/- 2.2 for large tumors (> 5 cm, n = 12), 3.7 +/- 1.8 for medium-sized tumors (3.1-5.0 cm, n = 11), and 3.5 +/- 1.7 for small tumors (< or = 3 cm, n = 4), with no significant differences noted among tumor sizes. Improvement in the VAS score was 3.5 +/- 1.3 for the 4 tumors in the RFA + bone cement group, 3.2 +/- 1.9 for the 5 tumors in the RFA + radiation therapy group, and 4.8 +/- 2.2 for the 18 tumors in the RFA group. No significant differences were identified between groups. The improvement in the VAS score was 3.8 +/- 2.3, 4.0 +/- 1.9, and 4.7 +/- 2.6 in patients with tumor necrosis rates of 0-49%, 50-74%, and 75-100%, respectively. No significant association was observed among these three groups. CONCLUSION: Percutaneous RFA therapy was effective in relieving pain due to metastatic bone tumors. No relationships appear to exist between initial response and tumor size, combined therapy, and percent tumor necrosis.

Adult↗

PubMedDate not supplied

CT perfusion of the liver during selective hepatic arteriography: pure arterial blood perfusion of liver tumor and parenchyma.

PURPOSE: To quantify pure arterial blood perfusion of liver tumor and parenchyma by using CT perfusion during selective hepatic arteriography. METHODS: A total of 44 patients underwent liver CT perfusion study by injection of contrast medium via the hepatic artery. CT-perfusion parameters including arterial blood flow, arterial blood volume, and arterial mean transit time in the liver parenchyma and liver tumor were calculated using the deconvolution method. The CT-perfusion parameters and vascularity of the tumor were compared. RESULTS: A complete analysis could be performed in 36 of the 44 patients. For liver tumor and liver parenchyma, respectively, arterial blood flow was 184.6 +/- 132.7 and 41.0 +/- 27.0 ml/min/ 100 g, arterial blood volume was 19.4 +/- 14.6 and 4.8 +/- 4.2 ml/100 g, and arterial mean transit time was 8.9 +/- 4.2 and 10.2 +/- 5.3 sec. Arterial blood flow and arterial blood volume correlated significantly with the vascularity of the tumor; however no correlation was detected between arterial mean transit time and the vascularity of the tumor. CONCLUSION: This technique could be used to quantify pure hepatic arterial blood perfusion.

Aged↗