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Biomedical subjects

K Takayasu

Publications and source records attributed to K Takayasu.

At least 55 records · Page 3Linked to original sources
PubMed1992

Angiography in portal hypertension.

In this article, various angiographic techniques that may be useful in the assessment of portal hemodynamics are described with illustrative angiograms, providing examples of celiac arteriography; arterial venography; transsplenic, umbilical, operative, and transhepatic portography; hepatic venography; and other techniques. When they are combined with other imaging modalities, the information gained increases. Interventional and therapeutic angiography, such as angiographic occlusion of a large shunt causing encephalopathy or of an arterioportal shunt, widening of a narrowed shunt, and perforation of membranous obstruction of the inferior vena cava, is discussed.

Catheterization↗
PubMed1991

[Hepatoblastoma: clinico-radiological study of fifteen cases].

From January 1976 to October 1989, 15 patients with hepatoblastoma who underwent surgery at the National Cancer Center Hospital were evaluated by clinico-radiological techniques. Eight patients were boys and seven were girls; their average age was 3 years and 5 months. Abdominal mass or distention was initially noted in 12 patients. Alpha-fetoprotein level was extremely high (average, 327 micrograms/ml) in all cases but one. Hepatitis B surface antigen was negative in all cases. Tumors occupied mainly the right lobe of the liver in 67% of patients, and the mean tumor diameter was 11.1 cm. Of 15 hepatoblastomas, 10 were grossly classified as massive type and five as multinodular. Histopathological diagnosis was well differentiated (fetal type) hepatoblastoma in 10 patients and poorly differentiated (embryonal type) hepatoblastoma in five. Fibrous capsule was also recognized in eight. The noncancerous liver was normal in all cases. Ultrasonography (US) (n = 7 patients) demonstrated an inhomogeneous internal echo with well demarcated margin in five cases and without such margin in two. Nonenhanced CT (n = 6) showed an isodense or low density mass in all cases. Drip infusion CT (n = 5) revealed isodensity in the early phase. Dynamic CT performed in one patient showed a well enhanced mass that appeared hypervascular on angiography. Preoperative chemotherapy and radiation therapy provoked histological changes such as necrosis, fibrosis and calcifications. These changes were reflected on CT images. Both US and CT demonstrated the characteristic internal structure and gross appearance of hepatoblastoma.

Adolescent↗
PubMed1991

[Imaging diagnosis of small hepatocellular carcinoma by CT during arterial portography and Lipiodol-CT].

To evaluate the rates of detection for CT during arterial portography (CTAP) and Lipiodol-CT in small hepatocellular carcinoma (HCC), including early stage HCC, a comparative prospective study was performed in 24 candidates for surgery with 39 histopathologically proved lesions: eight lesions of early HCC, four of early advanced HCC and 27 of advanced HCC. The following results were obtained. 1) Ten of 24 patients had multiple primary HCC foci, 70% of which were, moreover, located in different segments. 2) Detection rates for digital subtraction angiography (DSA), CTAP and Lipiodol-CT were 67%, 87% and 72%, respectively. For 13 lesions undetected by DSA, the detection rates for CTAP and Lipiodol-CT were 62% and 31%. 3) For small HCC (n = 16) of less than 2 cm in diameter, CTAP (75%) tended to be superior to Lipiodol-CT (44%). 4) For early HCC (n = 8), CTAP (63%) showed a significantly higher detection rate than Lipiodol-CT (25%). 5) In contrast, detection rates for small (less than or equal to 2 cm) early advanced (n = 3) and advanced HCCs (n = 5) were almost the same: 67% and 100% by CTAP and 67% and 80% by Lipiodol-CT, respectively. To diagnose multiple primary HCCs in a candidate for surgery, CTAP is imperative following angiography.

Aged↗
PubMed1991

[Clinical application of helical scanning CT of upper abdomen].

The helical scanning CT unit, in which an X-ray tube continuously rotates at the rate of one revolution per second with constant movement of the table on which the patient is placed, was clinically tested in scanning of upper abdomen. Quality of the images obtained was equal to that of conventional CT. The images were particularly good at an X-ray beam width of 5 mm and table movement of 5 mm/sec with scan parameters of 120 kvp, 200 mA. Because of limitation of the X-ray tube capacity. X-ray beam width of 5 mm and table movement of 10 mm/sec with scan parameters of 120 kvp, 150 m, would be the most appropriate clinically. Application of the helical scanning CT will result in examination times shorter than in the case of conventional high-resolution CT and be obtained images at early vascular enhancement phase through the whole scanning area, so that it can be expected to be extremely useful in clinical diagnosis involving upper abdomen.

Adult↗
PubMed1991

[Radiologic features of focal nodular hyperplasia. Comparison with hepatocellular carcinoma by angiography and CT scan].

Radiographic features of eight focal nodular hyperplasia (FNH) of livers of 6 patients were described in comparison with those of 72 hepatocellular carcinoma (HCC). In arterial angiograms, 3 of the examined 4 FNH showed a large tumor vessel entering the center of the lesion. However, 1 of the examined HCC (1/39) had such a vessel. Tumor vessels in all of the examined FNH (4/4) were mainly curvilinear, without an encased and obstructive appearance. These angiographic features were not found in the examined HCC (0/39). Spoke-wheel patterns of tumor vessels were observed in 2 FNH (2/4) and in 3 HCC (3/39). In CT scan without contrast imaging, 5 HCC (5/39) and 3 FNH (3/5) were isodense. One of HCC (1/50) and 3 FNH (3/5) were isodense in the late phases of dynamic CT images. 4 HCC (4/50) and 4 FNH (4/5) had an irregular margin in the lesions. 5 HCC (5/50) and 4 FNH (4/5) demonstrated central low density areas in lesions in the early phases of dynamic CT imaging. In the late phases of the image, central high density areas in lesions were found in 2 HCC (2/50) and 3 FNH (3/5). Based on the above radiographic features such as a large tumor vessel having a curvilineal appearance, irregular margin of the lesions in FNH, we conclude that it is possible to make a differential diagnosis between FNH and HCC clinically.

Adolescent↗
PubMed1991

Early hepatocellular carcinoma: MR imaging.

All areas in hepatic lesions designated as adenomatous hyperplasia (AH) with malignant foci have recently been recognized as cancer. AH with malignant foci can be classified into two types, depending on the presence of overt cancerous nodules. Lesions without macroscopic nodules are defined as early hepatocellular carcinoma (HCC), while those with a macroscopic component are defined as HCC with early components. A comparative study of early HCC and HCC with early components was performed with magnetic resonance imaging. Early HCC lesions (n = 20) were isointense (n = 11) and hyperintense (n = 9) on T1-weighted spin-echo images and isointense (n = 17), partially hyperintense (n = 2), or hypointense (n = 1) on T2-weighted spin-echo images relative to the surrounding liver. Lesions classified as HCC with early components (n = 8) were hyperintense (n = 5), isointense (n = 2), and of mixed signal intensity (n = 1) on T2-weighted images. T1-weighted imaging was superior to T2-weighted imaging in depicting early HCC, but the latter could be useful in evaluating the progression of HCC in the histopathologically early stages.

Carcinoma, Hepatocellular↗
PubMed1991

Changes in mode of response to chemotherapy for hepatocellular carcinoma induced by transarterial embolization. A case report.

A 61-year-old man received systemic mitoxantrone chemotherapy following transarterial embolization of a large hepatocellular carcinoma with extensive intrahepatic, lung and bone metastases. His serum alpha-fetroprotein levels were 199,000 ng/ml prior to chemotherapy. He was given 10 mg mitoxantrone/m2 (14 mg/dose) intravenously every three weeks, and showed a rapid decrease in his serum levels of alpha-fetoprotein. There was almost complete resolution of the multiple bilateral metastatic lung nodules at five weeks and a marked decrease in the size of the intrahepatic metastatic nodules by seven weeks. The primary tumor, however, which had been previously treated by transarterial embolization, only underwent a 33% reduction in size according to WHO criteria. This occurred despite the disappearance, demonstrated by contrast enhanced computed tomography, of all viable tumor tissue. Ultrasonography also revealed only a minor regression, and could demonstrate no changes in the tumor echo pattern. The response pattern observed in this patient indicates the response to chemotherapy for hepatocellular carcinoma to be modified by prior transarterial embolization.

Carcinoma, Hepatocellular↗
PubMed1991

Accelerated tumor growth and changes in images concomitant with vascularization in a patient with hepatocellular carcinoma.

We examined serial changes of tumor images in a patient with hepatocellular carcinoma. The hepatocellular carcinoma was initially detected as a homogeneous low-echo area with unclear margins, which was not enhanced by contrast media on computed tomograms, and did not reveal any vascular abnormalities on hepatic angiography. About 11 months later, the tumor growth accelerated, with a parallel increase in serum alpha-fetoprotein levels, and the ultrasonographic features of the tumor changed from a homogeneous low-echo area to a mixed low- and high-echo area with a peripheral low-echo zone. Hepatic angiography revealed a hypervascular tumor at this time. The present case indicates that tumor growth and imaging patterns of hepatocellular carcinoma are closely related to vascularization of the tumor.

Carcinoma, Hepatocellular↗
PubMed1991

Spontaneous massive hemorrhage within a malignant tumor of the liver: diagnostic features in sonography and CT.

Computed tomography (CT) and sonography performed on four patients with histopathologically proven massive intratumoral hemorrhages in the liver were compared with pathological findings. Unenhanced CT showed a round low-density mass, and enhanced CT produced slight enhancements in the peripheral portions of the masses in two patients which corresponded to histopathologically viable cancerous portions. In contrast, sonography showed multilocular cystic masses with variously shaped septa, assuming a honeycomb appearance. Histopathologically, the septa were made up of blood clots with or without granulation tissue, scar and viable tumor, and the cystic spaces were filled with exudate and erythrocytes. Combined study by CT and sonography could be useful in differentiating massive hemorrhagic malignancies from cystic and necrotic masses and/or simple hemorrhagic lesions. The danger of malignant tumors with massive hemorrhage possibly being diagnosed as benign lesions, such as hematomas and abscesses, is also stressed.

Adolescent↗
PubMed1991

Adenocarcinoma and concomitant intraductal papillary adenoma in the pancreas.

A 72-year-old man was found to have a 12 mm solid lesion in the pancreatic tail and an 8 mm cystic lesion in the body of the pancreas by computed tomography carried out during a routine follow-up study of his adult-onset diabetes mellitus. A distal pancreatectomy was performed revealing the pancreas to have an adenocarcinoma in the tail and a conglomeration of intraductal papillary adenoma in the body. A review of the literature disclosed similar coexistences of cystadenoma and carcinoma in four patients, none of which was documented with preoperative imaging features such as we had.

Adenocarcinoma↗
PubMed1991

A hepatoblastoma originating in the caudate lobe radically resected with the inferior vena cava.

Complete resection of a rare hepatoblastoma in the caudate lobe, involving the inferior vena cava (IVC), is reported. After systemic chemotherapy, a 5-year-old child underwent exploratory laparotomy at another hospital, but resection was not attempted because the tumor in the caudate lobe had extensively invaded the retrohepatic IVC. However, because not only the lack of distant metastases but also the establishment of extrahepatic collaterals were confirmed by imaging, we thought it was possible to radically resect the tumor. We successfully performed an extended left hepatic lobectomy including total excision of the caudate lobe and the involved portion of the IVC. Although we did not reconstruct the IVC, no clinical manifestations arising from caval congestion were seen. The serum alpha-fetoprotein value declined below the normal limit. Our experience with this case has introduced a radical resectability for hepatic malignancy in the caudate lobe, even if it has extended into the IVC.

Carcinoma, Hepatocellular↗
PubMed1991

A new method for mapping hepatic subsegment: counterstaining identification technique.

Hepatic subsegmentectomy requires identification of the borders of tumor-bearing subsegment, usually achieved by injecting dye into the portal veins feeding the domain. We describe an alternative technique for performing systematic subsegmentectomy in patients with cirrhosis and hepatocellular carcinoma, in whom hepatic arterial and portal venous embolizations were already performed as a preoperative adjuvant. Under ultrasonic guidance, each of the neighboring portal units is sequentially stained, thus defining the avascular subsegment to be resected as the nonstaining area. This allows the subsegment to be totally resected. This counterstaining identification technique can be used for all subsegments undergoing complete embolization and for other situations in which the usual staining method is impossible because of the presence of arterioportal shunting or portal tumor thrombus.

Carcinoma, Hepatocellular↗
PubMed1991

The value of ultrasonography for hepatic surgery.

Ultrasonography plays an important role in the early detection of hepatocellular carcinoma. Ultrasonography detected 53% of 287 patients with small (less than or equal to 5 cm) hepatocellular carcinomas. Among 486 patients with hepatocellular carcinomas, sensitivities of intra-operative ultrasonography in detecting 451 small primary hepatocellular carcinoma nodules, intrahepatic metastasis in 330 patients with small hepatocellular carcinoma and 63 tumor thrombi were 98, 48 and 67%, respectively. The sensitivity of intra-operative ultrasonography in detecting small primary tumors was 10% better than ultrasonography, computed tomography, and angiography. The sensitivity of intra-operative ultrasonography in intrahepatic metastasis and tumor thrombus was two to three times better than pre-operative examination. Intra-operative ultrasonography was useful in detecting nonpalpable tumors and in guiding the transection of the liver, biopsy, and cryosurgery. Moreover, intra-operative ultrasonography made possible new hepatectomy procedures: systematic subsegmentectomy and hepatectomies which preserve the inferior right hepatic vein. Systematic subsegmentectomy guided by intra-operative ultrasonography resulted in better survival rates than the limited resection in patients with small hepatocellular carcinoma two years after hepatectomy; by the sixth year, this difference was significant (p less than 0.05). Ultrasonography and intra-operative ultrasonography are indispensable in the early detection, accurate diagnosis, operative guidance and postoperative care of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1990

[Liver metastases of mucinous colorectal carcinoma: clinico-radiological study of six cases].

Clinico-radiological study was attempted in 6 cases of liver metastases from mucinous colo-rectal carcinoma. On plain Computed Tomography (CT) scans (n = 6), tumors were demonstrated as a low density area in 83% and its margin was unclear and irregular in all cases. On enhanced CT scans (n = 6), marginal enhancement of the lesion was recognized in 50%, while neither internal enhancement nor peripheral low density area as commonly seen in metastatic adenocarcinoma was revealed. Ultrasonography (US) (n = 5) showed homogeneous echogenic mass in all lesions and angiography (n = 4) did hypovascular mass with displacement above. For differential diagnosis of mucinous carcinoma from adenocarcinoma metastasized from colo-rectal cancer, integrated diagnosis using CT and US is necessary.

Adenocarcinoma, Mucinous↗