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Biomedical subjects

H Oi

Publications and source records attributed to H Oi.

At least 55 records · Page 3Linked to original sources
PubMed1994

Time-of-flight MR angiography of portal system and collaterals in portal hypertension using a 2-DFT fast spoiled gradient recalled steady-state precession technique.

MR angiographic examinations were performed in 26 patients. Approximately 30 contiguous fast spoiled GRASS images (8.1/3.1/30 degrees, TR/TE/flip angle) were acquired during single breath-holding for about 35 s, and then new images were reconstructed with maximum intensity projection technique. Spoiled GRASS images (40/12/40) of 2 to 3 slices were taken during breath-holding for about 13 s, and these processes were repeated to obtain about 30 individual images for conventional MR angiography. The new MR angiograms were compared quantitatively and qualitatively with conventional MR angiograms with arterial portography as the gold standard. The new MR angiograms could visualize blood vessels with smooth margins, and provided almost the same anatomic information about the portal vein and collateral vessels as the conventional MR angiograms. Contrast-to-noise ratios between the portal or hepatic vein and liver parenchyma were significantly higher with fast spoiled GRASS images. The new MR angiograms using fast spoiled GRASS images provided useful diagnostic mapping of the collateral venous pathways within a shorter examination time.

Adult↗
PubMed1993

[CT assessment of residual contrast medium in the kidney 12-24 hours after angiography].

Residual contrast medium in the kidney on delayed film is sometimes reported in patients with problems in the urinary system following the administration of contrast medium. However, we frequently found residual contrast medium in the kidney of patients with normal renal function on delayed CT after angiography. Thus we carried out CT examination 12-24 hours after angiography with four kinds of contrast media to prospectively study the incidence of residual contrast medium in the kidney. Residual contrast medium in the kidney was observed on delayed CT in 286 of 536 patients (53%). We found a relatively higher incidence with ioxaglate (63%) and iohexol (60%) than that with iopamidol (28%) and diatrizoate (38%). The incidence of residual contrast medium in the kidney increased with the dose of contrast medium administered except in the case of iopamidol. The influence of hepatobiliary and renal function on residual contrast medium in the kidney was examined. We found a higher incidence of residual contrast medium in the group with abnormal hepatobiliary function than in the group with normal function. This implied that the hepatobiliary pathway is an important tract in the excretion of contrast medium even if the dose of excretion is small. A high frequency of residual contrast medium in the kidney was recognized on delayed CT not only in the renal dysfunction group but also in the normal renal function group. We suggest that residual contrast medium in the kidney is a normal phenomenon on delayed CT.

Adolescent↗
PubMed1993

[Appearance of low intensity band seen around the abdominal organs on gradient echo image].

To clarify the mechanism of appearance of low intensity band seen around the abdominal organ, we performed phantom study. The resected intestine, which filled with water and fixed in the salad oil, was obtained by spoiled GRASS MR imaging with variable TEs and fixed TR. On in phase image, low intensity band was seen in low frequency side of frequency encoding direction of surface of the intestine, and high intensity band in high frequency side. On out of phase image, low intensity band is seen all around the intestine. Our phantom study verified that the appearance of low intensity band on out of phase gradient echo image is due to both the misregistration and signal void caused by chemical shift artifact.

Adipose Tissue↗
PubMed1993

Nasal septal neurinoma.

A case of nasal septal neurinoma is presented. The patient was a 71-year-old male who complained of nasal obstruction and epistaxis. Results of the physical examination showed a giant mass filling the nasal cavity and the nasopharynx. A biopsy taken from its tissue surface showed histological features of neurofibroma. The lesion was completely resected with the patient under general anesthesia. The tumor completely occupied the right nasal cavity and the nasopharynx, partially penetrated the nasal septum and extended to the left nasal cavity. After the operation, the final pathological diagnosis was not neurofibroma but neurinoma in which Antoni type A and type B cells were mixed. The postoperative course was uneventful, and no recurrence has been observed to date.

Aged↗
PubMed1993

[Studies on combination therapy with TAE and percutaneous ethanol injection therapy for unresectable hepatocellular carcinoma].

We studied and analysed the effects of combination therapy with TAE and PEIT for unresectable HCC. The subjects were 28 patients (21 males, 7 females) with 31 tumors treated in the Department of Surgery, Osaka Teishin Hospital. The patients were divided into four groups on the basis of the tumor size (< 3 cm, 3-5 cm, 5-8 cm, > 8 cm). The therapeutic effect on the tumors was evaluated on the basis of the maximum reduction rate within 3 months after TAE and PEIT. The response rates after treatment were 87.5%, 60.0%, 25.0% and 0% for < 3 cm, 3-5 cm, 5-8 cm, and > 8 cm tumor size, respectively. The 50% survival period was 50.9 months. The 1-, 2-, 3- and 5-year survival rates were 92%, 76%, 52% and 32%, respectively. In the cases of over 8 cm, this combination therapy had no effects on the survival period. The findings of the present study suggest that the combination therapy was useful for the unresectable HCC of under 5 cm in diameter.

Carcinoma, Hepatocellular↗
PubMed1992

[CT assessment of gallbladder opacification 12-24 hours after angiography].

After the injection of conventional contrast agents that are largely excreted in urine, gallbladder opacification is observed in patients with renal dysfunction. However, some reports have noted that gallbladder opacification on plain radiographs occurs frequently in patients without renal impairment after the intravenous administration of Ioxaglate, one of the new low-osmolality agents. We carried out CT examination 12-24 hours after angiography with various kinds of contrast media in 437 patients to examine the incidence of gallbladder opacification. The influence of hepatobiliary and renal function on the excretion of contrast medium is discussed. Gallbladder opacification was observed in more than 60% of the patients. This result indicates that gallbladder opacification is not a rare phenomenon, and is even common in delayed CT examinations of patients with normal renal function. The high frequency of gallbladder opacification was recognized not only in the renal dysfunction group but also in the normal liver function group. Gallbladder opacification in delayed CT examination shows that the hepatobiliary tract is important in the excretion of contrast medium.

Adolescent↗
PubMed1992

[Image-transmission using 64 kbps-ISDN (Integrated Services Digital Network) and mini-PACS].

We carried out the image-transmission using 64kbps-ISDN between two image workstations (IWS) of mini-PACS installed at the Department of Radiology, Osaka Teishin Hospital and the Kashiwa Works, Hitachi Medical Corporation. The distance between Osaka and Kashiwa is about 600 km. The subtraction of two images before and after transmission revealed no change of the data of the image during transmission. For 1/2 compression image, the times of image-transmission of 256 x 256, 320 x 320 and 512 x 512 matrix were 9, 17 and 33 second, respectively. The efficiency of image-transmission was about 80%. Using ISDN, we can make an accurate, rapid and cheap image-transmission.

Computer Communication Networks↗
PubMed1992

Efficacy of combination treatment--(TAE with adriamycin and ethanol)--for hepatocellular carcinoma.

Among 44 patients with hepatocellular carcinoma (HCC), combination treatment with both transhepatic arterial embolization (TAE) and ethanol injection therapy (EIT) was performed in 10 patients. Only two had tumors measuring less than 3 cm in diameter. In all, eight patients had solitary tumors and two had multiple tumors. The tumor was classified as stage I in one patient, stage II in six subjects, stage III in two patients, and stage IV in one subject prior to TAE, but one stage II case was changed to stage III after laparotomy. The clinical stage was I in two patients, II in six subjects and III in two patients. Five patients with tumors of stages I and II achieved either a complete response (CR) or partial response (PR). However, three patients with tumors of stages III and IV showed progressive disease (PD). Thus, the response rate (CR+PR) was 50%. For tumor stages I and II, the 1-, 2-, and 3-year survival values were 100%, 100%, and 83%, respectively. For tumor stages III and IV, the 1- and 2-year survival values were 75% and 25%, respectively. Combination treatment of HCC appears to be efficacious for tumor stages I and II.

Adult↗
PubMed1992

Outcome of localized hepatocellular carcinoma treated with segmental arterioportal chemoembolization.

When lipiodol is injected into the hepatic artery at a dose exceeding a certain level, it flows into the portal vein. On the basis of this feature, an emulsion of Adriamycin with lipiodol was injected into a segmental or subsegmental artery such that it was delivered to the portal vein of the same segment, and the artery was then embolized with Gelfoam. This segmental arterioportal chemoembolization (cement therapy) was performed in 50 patients with localized hepatocellular carcinoma. A posttreatment CT scan showed that almost 100% of the lesions were occupied by lipiodol. The cumulative survival values determined for the 50 patients were very high: 83.4% after 1 year and 62.7% after 2 years.

Adult↗
PubMed1991

Prevention of gastric complications in hepatic arterial chemoembolization. Balloon catheter occlusion technique.

Gastric complications may be a problem in transcatheter arterial chemoembolization, if the right gastric artery branches distally from the proper hepatic artery or its branch, or the accessory left gastric artery arises from the left hepatic artery. We occluded the proper hepatic artery with a balloon catheter to redirect blood flow in these gastric branches toward the liver. This procedure prevented chemoembolic agents from flowing into the gastric branches, and accordingly protected against gastric complications even when chemoembolization was performed by injecting the agents proximally to the gastric branches.

Carcinoma, Hepatocellular↗
PubMed1990

Hepatic neoplasms: effects of transcatheter arterial embolization on coagulation and fibrinolysis.

Forty-eight patients with hepatic malignancy (47 with hepatocellular carcinoma, one with metastatic colon carcinoma), who underwent transcatheter arterial embolization (TAE) for treatment of hepatic neoplasms, were investigated to determine the effects of TAE on coagulation and fibrinolysis. TAE was followed by a significant decrease in the platelet count (P less than .001); a prolongation of prothrombin time (P less than .001); an early increase in levels of fibrinopeptide A (P less than .01), fibrinopeptide B beta-15-42 (P less than .001), and fibrin(ogen) degradation products (P less than .001); and a delayed increase in the fibrinogen level (P less than .001), without a significant prolongation of the activated partial thromboplastin time. In the three patients who developed disseminated intravascular coagulation (DIC) after TAE, a reduction of both the platelet count and fibrinogen level occurred significantly earlier and in a more severe form than in the other patients without DIC; this reduction preceded the onset of the characteristic symptoms of DIC. Data suggested that close monitoring of platelet count and fibrinogen level is important for early detection of DIC following TAE.

Adult↗
PubMed1990

Treatment of hepatocellular carcinoma by segmental hepatic artery injection of adriamycin-in-oil emulsion with overflow to segmental portal veins.

Hepatocellular carcinoma was treated with slow injection of an emulsion containing 40 to 60 mg of adriamycin and 3.5 to 12 ml of Lipiodol into the portal vein via a segmental hepatic artery. During and after the injection, the portal branches of the segment were demonstrated. Six patients with resectable hepatocellular carcinoma received this treatment, which in 3 of them was followed by embolization with Gelfoam of the segmental artery. In these 3, all main tumors and daughter nodules became completely necrotic, but some infarction developed in the non-tumorous area. Those without Gelfoam had complete necrosis of all daughter nodules, but incomplete response of the main tumor. This combined treatment may be recommended for patients with localized lesions which are nonresectable due to cirrhosis, or for other reasons.

Aged↗
PubMed1989

Transcatheter oily chemoembolization of hepatocellular carcinoma.

Since 1983, transcatheter oily chemoembolization (TOCE) with doxorubicin hydrochloride, iodized oil, and gelatin sponge was used in 100 patients with hepatocellular carcinoma. Doxorubicin, 40-100 mg (mean, 61.3 mg), was mixed with 5-20 mL (mean, 9.6 mL) of an iodized oil to prepare a water-in-oil emulsion that was then infused into the hepatic artery. Both progressive changes in blood concentrations of doxorubicin and its tissue concentrations in patients who underwent hepatectomy demonstrated that the drug was released slowly from the emulsion. The cumulative survival rate was 82.0% for 6 months, 53.8% for 1 year, 33.3% for 2 years, and 17.6% for 3 years. These survival rates were better than those of 104 patients who underwent embolization with gelatin sponge, then received an anticancer drug (67.4% for 6 months, 45.2% for 1 year, 16.3% for 2 years, and 3.8% for 3 years).

Carcinoma, Hepatocellular↗
PubMed1989

[Limitation of oily chemoembolization against hepatocellular carcinoma and arterioportal segmental chemoembolization].

Emulsion of adriamycin and lipiodol added with Gelfoam has been used for the transcatheter oily chemoembolization against hepatocellular carcinomas. This therapy resulted in significantly increased cumulative survival as compared with chemoembolization therapy using anti-cancer drugs and Gelfoam. However, it was revealed to have the following limitations: Insufficient efficacy against micrometastases and extracapsular invasion; impossible to perform sufficient treatment for patients with severe hepatic disorders; and there were cases in which lipiodol was hardly retained. In order to overcome the limitations described above, we have performed segmental hepatic chemoembolization simultaneously from the hepatic artery embolization simultaneously from the hepatic artery and portal vein. This method works on the basis of the fact that excess amount of lipiodol emulsion infused from the hepatic artery flows into the portal vein. Gelfoam embolization is also added in this method. Though subjects appropriate for this newly developed method are restricted, all the tumors in the objective segment of the liver can undergo necrosis. The efficacy is comparable to the effects of hepatectomy. In addition, since the other segments of the liver are able to be kept in reserve, this method is able to be applied to patients with severe hepatic disorders.

Aged↗