Biomedical subjects

C Kuroda

Publications and source records attributed to C Kuroda.

At least 55 records · Page 3Linked to original sources

PubMed1993

MR angiography of meningioma.

The clinical evaluation of three-dimensional time-of-flight MR angiography was prospectively performed in 16 patients with intracranial meningioma. MR angiographic techniques used in this study both with and without gadopentetate dimeglumine made it possible to demonstrate the topographic relationship between the tumors and the neighboring vascular structures. MR angiograms were compared with available conventional angiograms. The three-dimensional enhanced MR angiograms were successful in depicting sinus involvement in greater detail in six patients than conventional angiography. In six patients, the feeding arteries of meningiomas were demonstrated with the unenhanced MR angiograms. However, MR angiograms failed to show small feeding arteries in three patients as delineated with conventional angiography. Arterial displacement was shown in nine patients. Venous drainage and collateral circulations were also visualized in four patients. Our results indicate that multiview MR angiograms noninvasively provide useful information for planning the surgical treatment of patients with meningioma.

Cerebral Angiography↗

PubMed1993

Magnetic resonance imaging-histologic correlation of small hepatocellular carcinomas adenomatous hyperplasias.

RATIONALE AND OBJECTIVES: Hepatocellular carcinomas (HCCs) usually consist of components of different histologic grade. Using surgically resected specimens, the authors obtained high-resolution magnetic resonance (MR) images and studied the relationship between histologic grade of HCCs and MR signal intensity. METHOD: In vitro MRI was performed on 15 small (less than 20-mm diameter) HCCs and 2 patients with adenomatous hyperplasia (AH) within 1 hour of surgical resection. In these 17 lesions, 24 macroscopic nodular components corresponding to MR images were recognized pathologically. The difference in MR signal intensity was examined by using tumor/phantom (T/P) signal-intensity ratio. In addition, the correlations between signal intensity on MRI and histologic criteria for grading HCC were studied. RESULTS: On T2-weighted images, grade II HCCs had significantly greater T/P values than grade I HCCs (P < .01). There is the correlation (r = .88, P < .001) between nucleocytoplasmic (N/C) ratio and signal intensity of small HCCs and AHs on T2-weighted images. CONCLUSION: The N/C ratio is an important factor relating the signal intensity to the histologic grade of these lesions on T2-weighted images.

Aged↗

PubMed1993

Bladder tumors: staging with gadolinium-enhanced oblique MR imaging.

To clarify the importance of imaging plane in evaluation of invasion by tumor into muscle, 50 patients with bladder tumors underwent examination with magnetic resonance (MR) imaging performed with an oblique plane and the early phase of contrast enhancement. After the ideal oblique plane was selected, an oblique T2-weighted image was obtained. Gadopentetate dimeglumine was then administered, and an oblique T1-weighted image was obtained. The staging based on oblique T2-weighted and oblique contrast material-enhanced T1-weighted MR images was then correlated with histopathologic staging. The respective accuracies of oblique contrast-enhanced T1-weighted and oblique T2-weighted images were 78% and 60% for overall staging (P < .05), 90% and 74% for differentiation between (a) stage T1 and lower-stage tumors and (b) stage T2 and higher-stage tumors (P < .05), and 92% and 88% for differentiation between (a) stage T2 and lower-stage tumors and (b) stage T3a and higher-stage tumors (P > .05). Oblique MR imaging performed in conjunction with the early phase of contrast enhancement showed significantly high staging accuracy, especially in differentiation between superficial tumors and tumors with superficial muscle invasion.

Adult↗

PubMed1993

Response to transcatheter oily chemoembolization in hepatocellular carcinoma 3 cm or less: a study in 50 patients who underwent surgery.

The response of 50 patients who underwent hepatectomy for hepatocellular carcinoma measuring 3 cm or less (at the time of surgery) to transcatheter oily chemoembolization was evaluated. The response was assessed in 5 categories, A: complete necrosis (100%), B: necrosis of at least 95%, C: at least 80%, but less than 95%, D: at least 50% but less than 80%, and E: less than 50% of the tumor cells. Response A was observed in 19 patients (38%), B in 7 (14%), C in 9 (18%), D in 7 (14%), and E in 8 (16%). These results were classified with respect to the histological degree of tumor differentiation, the WHO histological classification, the microscopic patterns of tumor growth, and macroscopic classification. The response was evaluated in relation to the histological grade of tumor differentiation and the WHO histological classification in all categories of response except response A, and there was no significant difference between the categories. The response was obviously better with the expansive type than with the replacing type. Single nodular type lesions were more responsive than the single nodular type lesions with extranodular growth and the contiguous multinodular type. Pretreatment estimation of the microscopic patterns of tumor growth and macroscopic classification appears to be valuable in predicting prognosis.

Adult↗

PubMed1992

[Regenerating nodules in liver cirrhosis--patho-MR-serological correlation study].

An MR study was performed in 73 clinically diagnosed cirrhotic patients to determine correlations among the demonstration of small low intensity nodules (SLINs), secondary changes due to cirrhosis, and serological data. In 32 patients, liver cirrhosis was proved histologically. SLINs were observed in 38 of the 73 patients on gradient echo (GRE) images and in 28 patients on T2-weighted SE images. Patho-MR correlation study of the liver in the 32 histologically proved cirrhotic patients revealed that SLINs were seen on GRE images only in patients with iron deposits in regenerating nodules (RNs). There was no significant correlation between secondary changes due to liver cirrhosis and the demonstration of SLINs. Serological data indicating liver cell injury and iron store in the body were significantly higher in patients with iron deposits in RNs than in those without iron deposits.

Adult↗

PubMed1992

Prospective and randomized clinical trial for the treatment of hepatocellular carcinoma--a comparison of lipiodol-transcatheter arterial embolization with and without adriamycin (first cooperative study). The Cooperative Study Group for Liver Cancer Treatment of Japan.

A randomized, controlled clinical trial comparing the use of lipiodol-transcatheter arterial embolization (L-TAE) in the presence versus the absence of Adriamycin (ADR) for the treatment of hepatocellular carcinoma was conducted from August 1988 through September 1989. In all, 125 Japanese hospitals participated in this study and 289 patients were entered in the trial. The patients were randomly allocated into group A (L-TAE) or group B (L-TAE + ADR) by telephone registration. There was no significant difference in background factors between group A and group B. Additional treatment, including repeated TAE or hepatic resection, was given to 189 patients. Among the four endpoints analyzed, the rate of tumor reduction and lipiodol accumulation in the tumor did not significantly differ between the two groups. The 3-year survival values for groups A and B were 33.6% and 34.9%, respectively; the difference was not significant. The serum alpha-fetoprotein level, however, decreased to a significantly greater extent in the group that received ADR than in the group that did not (P < 0.05). This result suggests that ADR has some favorable additional effect in L-TAE for the treatment of hepatocellular carcinoma.

Adult↗

PubMed1992

Prospective and randomized clinical trial for the treatment of hepatocellular carcinoma--a comparison of L-TAE with Farmorubicin and L-TAE with adriamycin (second cooperative study). The Cooperative Study Group for Liver Cancer Treatment of Japan.

A randomized clinical trial comparing L-TAE with Farmorubicin (FARM) and L-TAE with Adriamycin (ADR) in the treatment of hepatocellular carcinoma was conducted from October 1989 through December 1990. In all, 192 hospitals participated in this study and 117 patients were entered. The patients were randomly allocated to group A (L-TAE+FARM) or group B (L-TAE+ADR). There was no significant intergroup difference in background factors. Additional treatment consisting of repeated TAE or surgery was given to 66 patients. Four factors were analyzed in this study: the percentage of reduction in tumor size, the change in the AFP level, lipiodol accumulation, and survival. None of these factors differed significantly between the two groups. The final evaluation of this study will be based on differences in survival after a long-term follow-up. Toxic effects manifested less frequently in group A than in group B, and the decrease in the platelet count in the peripheral blood was significantly lower in group A than in group B. These results suggest that FARM exerts a more favorable effect than does ADR in the treatment of hepatocellular carcinoma.

Adult↗

PubMed1992

Selection of therapeutic modalities for hepatocellular carcinoma in patients with multiple hepatic lesions.

In the present study, we compared the survival of patients with multi tumor hepatocellular carcinoma (HCC) following their treatment with liver resection versus TAE. A total of 336 HCC patients were treated at Osaka University Hospital between 1980 and 1989. Of these, 140 patients underwent liver resection in the presence or absence of TAE and 173 subjects were treated with TAE alone. Our TAE protocol consisted of 50 mg Adriamycin, 3-5 ml lipiodol, and Gelfoam. The 1-, 3-, and 5-year survival values found for the liver resection group were 87.4%, 66.0%, and 47.4%, respectively, whereas the values calculated for the TAE group were 64.6%, 29.9%, and 15.8%, respectively. The survival of patients in the resection group was clearly better than that of subjects in the TAE group. Of the 140 patients who underwent resection, 36 cases were proven to have multiple lesions by histopathological examination. The 1- and 3-year survival values determined for this special group were 67.9% and 33.3%, respectively. Of the TAE cases, 113 were diagnosed as having multiple lesions by imaging examination, and their 1- and 3-year survival values were 59.7% and 24.9%, respectively. No significant differences in survival was found between these two different treatment modalities for these multiple-lesion cases. The results of this study indicate that it is unlikely that surgical resection is superior to TAE alone for the treatment of HCC patients with multiple lesions.

Adult↗

PubMed1992

Effectiveness of Lipiodol in transcatheter arterial embolization of hepatocellular carcinoma.

The effectiveness of Lipiodol (iodized oil) in transcatheter arterial embolization (TAE) of hepatocellular carcinoma (HCC) was retrospectively evaluated using statistical analysis. A total of 343 HCC patients who underwent TAE at 5 institutions between 1984 and 1989 were divided into 2 groups: the GS-TAE group underwent TAE with Gelfoam sponge alone, whereas the LP-TAE group was given Lipiodol (LP) immediately before GS-TAE. The statistical T value calculated for the LP-TAE group showed that the administration of LP, the tumor size, intrahepatic metastasis, portal vein infiltration, and serum total bilirubin and alpha-fetoprotein levels significantly (P < 0.01) affected the patients' survival. Both the cumulative survival determined using the Kaplan-Meier model and the cumulative hazard calculated using Cox's proportional hazard model differed significantly (P < 0.01) between the GS-TAE group and the LP-TAE group (log-rank test). These results confirmed the effectiveness of LP used in combination with Gelfoam sponge for TAE of HCC.

Aged↗

PubMed1992

Preoperative indications for extended pancreatectomy for locally advanced pancreas cancer involving the portal vein.

This retrospective study attempted to determine the indications for extended pancreatectomy for locally advanced carcinoma of the pancreas, in terms of postoperative prognosis. An extended pancreatectomy with portal vein or superior mesenteric vein (PV/SMV) resection and regional lymphadenectomy was performed in 35 of 50 consecutive cancers that extended into the retroperitoneal spaces and involved the PV or SMV. Among the many background factors in the 35 resected specimens, the degree of PV/SMV invasion by the cancer was most closely associated with prognosis, despite resection of all involved PV/SMV. This factor generally correlated with the preoperative findings on the portal phase of superior mesenteric arteriograph. In 17 selected patients in whom PV/SMV invasion had been angiographically both semicircular or less and 1.2 cm (1.4 cm on the film) or less in length, the 3-year survival rate was 59%. This survival rate was significantly higher than the 29% 3-year survival rate in all 35 patients (p less than 0.05). Conversely, among the 18 patients in whom invasion was angiographically either beyond semicircular or more than 1.2 cm (1.4 cm on the film) in length, there were no 1.5-year survivors, and this result was even worse than that of 15 nonresectable cases. Based on postoperative survival, the degrees of PV/SMV invasion on preoperative angiography (narrowing pattern and length) are good indicators for aggressive pancreatectomy for locally advanced pancreatic cancer.

Adenocarcinoma↗

PubMed1991

Limitation of transcatheter arterial chemoembolization using iodized oil for small hepatocellular carcinoma. A study in resected cases.

The radiologic and histologic findings are presented of the resection of 14 small hepatocellular carcinomas (HCC), less than 2 cm in maximum diameter, after transcatheter arterial chemoembolization (TCE) using iodized oil. The effect of TCE on small HCC depended on the morphologic type of the tumors. When no extracapsular invasion of tumor cells occurred, TCE was extremely effective against encapsulated tumors. However, in nine of the 14 resected specimens, viable tumor cells remained in or around the tumor. The authors suggest that small HCC are not always curable with TCE alone and that a multi-disciplinary approach is necessary for patients with small HCC.

Aged↗

PubMed1991

Portal-systemic encephalopathy: presence of basal ganglia lesions with high signal intensity on MR images.

Sixteen patients with cirrhosis of the liver underwent cranial magnetic resonance (MR) imaging and transarterial portography to evaluate the relationship between basal ganglia lesions and portal-systemic collateral vessels. No neuropsychiatric disturbance was observed in any of the patients at the time of the MR examination, but four patients with portal-systemic encephalopathy were included in the study. Basal ganglia lesions, characterized by increased signal intensity on T1-weighted MR images, were observed in nine of the 16 patients, including the four with portal-systemic encephalopathy. These nine patients had large portal-systemic collateral vessels that were more than 10 mm in diameter. These collateral vessels were receiving blood from the superior mesenteric vein (SMV) in all nine patients. The lesions involved the globus pallidus and portions of internal capsules in a bilateral and symmetric fashion and did not exhibit mass effect. The authors conclude that there may be a significant relationship between high-intensity basal ganglia lesions and large portal-systemic collateral vessels receiving blood from the SMV.

Aged↗

PubMed1991

Prevalence of air bronchograms in small peripheral carcinomas of the lung on thin-section CT: comparison with benign tumors.

Despite improved techniques--such as bronchoscopy and percutaneous needle biopsy--to evaluate pulmonary nodules, there are still many cases in which surgical resection is necessary before carcinoma can be differentiated from benign lesions. The present study was undertaken to determine if the presence of an air bronchogram or air bronchiologram (patent visible bronchus or bronchiole) is useful in distinguishing small lung cancers from benign nodules. Thin-section chest CT scans were obtained in patients with 20 peripheral lung cancers less than 2 cm in diameter (18 adenocarcinomas, one squamous cell carcinoma, and one large cell carcinoma) and 20 small benign nodules (eight hamartomas, seven tuberculomas, two foci of aspergillosis, one focus of cryptococcosis, one chronic focal interstitial pneumonitis, and one plasma cell granuloma). The images were compared with regard to the patency of any bronchus or bronchiole within the lesions. After surgical resection, the specimens were inflated with agar and sectioned transversely to correlate gross morphology and low-power histologic sections with the CT appearance. An air bronchogram or air bronchiologram was seen in the tumors on 65% of CT scans and 70% of histologic sections. Benign nodules had a patent bronchus or bronchiole on CT scans and histologic sections in only one case (5%). These findings suggest that the presence of an air bronchogram in a lung nodule is a useful finding to help differentiate adenocarcinomas from benign lesions.

Adenocarcinoma↗

PubMed1990

[Dynamic MRI of liver tumors--evaluation by inversion recovery snap shot FLASH MR imaging].

We have studied 20 patients with liver tumor (hepatoma 12, hemangioma 6, metastatic tumor 2) using inversion recovery snap shot FLASH dynamic MR imaging. After intravenous injection of Gd-DTPA, serial 17 images were obtained during 7 minutes. Hepatoma showed central enhancement on early phase (0-20 sec) in 11 patients and absent or less enhancement than surrounding liver parenchyma on late phase (1-3 min) in 12 patients. Hemangioma showed peripheral enhancement on early phase in 6 patients, and slight to moderate enhancement on late phase in 5 patients. Peripheral slight enhancement were seen on late and delayed (5-7 min) phase in two patients with metastatic liver tumor. These characteristic enhancement patterns should facilitate differential diagnosis of liver tumors.

Aged↗

PubMed1990

[Experimental studies of segmental hepatic artery embolization with a super absorbent embolic agent].

Super absorbent (Sumikagel) is a unique polymer mainly composed of polysodium acrylate (PSA). When PSA contacts water, it absorbs water and swells in a few seconds. This new embolic material suspended in Lipiodol (Lp-PSA), was used for hepatic artery embolization in five dogs. The purpose of this study is to examine the necrotizing effect of the new embolic material on segmental hepatic artery embolization. Gross liver examination demonstrated congestion and segmental infarction within the embolized area, and microscopically focal necrosis of liver parenchyma was observed. Segmental hepatic artery embolization with Lp-PSA should be an effective method of hepatic tumor embolization.

Absorption↗

PubMed1990

Effect of transcatheter arterial embolization on the boundary architecture of hepatocellular carcinoma.

Daughter nodules and intrahepatic metastases are resistant to conventional transcatheter arterial embolization therapy. To clarify the mechanism of this resistance, the boundaries of hepatocellular carcinomas and their relationship to the blood supply were studied. The boundaries of the hepatocellular carcinomas studied were classified as one of five types: encapsulated, granulation, stromal, replacing, or sinusoidal. The granulation and stromal types had a capsule-like structure, but lacked the hyalinization which is the hallmark of a true tumor capsule. The granulation and stromal types could also be differentiated from the encapsulated type because of their different blood supplies and the differing effects of transcatheter arterial embolization. When barium sulfate was infused into the portal vein, it did not enter into encapsulated tumors, but it entered granulation and stromal type tumors. Small nodules such as daughter nodules and intrahepatic metastases do not have capsules, and so have a blood supply that makes them resistant to conventional transcatheter arterial embolization therapy.

Autopsy↗

PubMed1990

Portal blood flow in congestive heart failure: pulsed duplex sonographic findings.

Twenty-one patients with congestive heart failure were examined with duplex sonographic scanning of the portal vein. The Doppler sonographic findings were compared with those of healthy subjects, patients with chronic liver disease, and patients with Budd-Chiari syndrome. Increasing pulsatility of the Doppler signals was demonstrated in 11 patients with severe congestive heart failure. Two patients with severe congestive heart failure showed decreasing pulsatility of portal Doppler signals in response to therapeutic procedures. Portal flow patterns suggestive of severe congestive heart failure include a monophasic forward flow with peak velocity in ventricular diastole and gradual diminution of velocity throughout ventricular systole (n = 5), a reversed flow velocity in ventricular systole (n = 3), and vena cava-like biphasic forward velocity peaks during each cardiac cycle (n = 2). The time-velocity waveform shape of portal flow is, to a large degree, influenced by the mechanical events in the right side of the heart in severe congestive heart failure.

Blood Flow Velocity↗

PubMed1990

Regenerating nodules in hepatic cirrhosis: MR findings with pathologic correlation.

To establish clearly the pathologic basis for small low-intensity nodules seen on MR images of the cirrhotic liver, we obtained MR images in 26 patients with cirrhosis in whom partial hepatectomy for hepatoma (15 patients), laparoscopy for cirrhosis (10 patients), or autopsy (one patient) was subsequently performed. Small low-intensity nodules were seen on gradient-echo images with short TEs (10-13 msec) in 13 of the 26 patients. In 12 of these 13 patients, small low-intensity nodules appeared larger and clearer as the TE was prolonged (14-25 msec). On T2-weighted spin-echo images, small low-intensity nodules were seen in 12 of the 13 patients, but not seen as well as on gradient-echo images. Pathologic correlation in these 13 patients revealed that the nodules on the MR images corresponded to iron deposits in regenerating nodules. Small low-intensity nodules were observed only on T2-weighted spin-echo images in two of the remaining 13 patients, in whom microscopic examination of the liver revealed marked inflammatory cell infiltration in the fibrous septa and no iron deposition. We conclude that small low-intensity nodules observed on MR images are caused by iron deposits in regenerating nodules, and that gradient-echo images with short and prolonged TEs are useful to confirm the presence of iron deposits in regenerating nodules.

Adult↗