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Biomedical subjects

C Kuroda

Publications and source records attributed to C Kuroda.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Unruptured intracranial aneurysms: evaluation with high-resolution MR angiography with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE)].

Forty-one patients with suspected intracranial aneurysms were evaluated by conventional three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) or high-resolution 3D TOF MRA with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE). Correlative study was done with conventional angiography in all patients. 3D TOF MRA detected 30 of 36 aneurysms depicted at conventional angiography. The overall rate of sensitivity for the detection of aneurysms was 83%. Unruptured aneurysms were unlikely to occur in the anterior communicating artery (3%), but were frequently found at the bifurcation of the middle cerebral artery (33%). Conventional MRA showed 7 of 9 aneurysms demonstrated at catheter angiography. The rate of sensitivity of conventional MRA for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 0% and 100%, respectively. High resolution MRA with MTC and TONE demonstrated 23 of 27 aneurysms detected by catheter angiography. Sensitivities of high resolution MRA with MTC and TONE for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 71% and 100%, respectively. Our results indicate that high-resolution 3D TOF MRA with MTC and TONE can provide precise, accurate depiction of intracranial aneurysms larger than or equal to 5 mm.

Adult↗
PubMed1996

Clinical features of small hepatocellular carcinomas as assessed by histologic grades.

BACKGROUND: Ninety-seven patients with small hepatocellular carcinomas (HCCs) measuring 3 cm or less in size and three patients with adenomatous hyperplasia who underwent radical hepatic resection were examined in this study. METHODS: The lesions were classified into four groups according to the following histologic grading criteria: group A, adenomatous hyperplasia (n = 3); group B, early HCC (n = 6); group C, well-differentiated HCC (wHCC) (n = 32); and group D, moderately or poorly differentiated HCC (n = 59). The involvement factors that seemed to be important or to characterize the progression of HCC and the survival rates were compared among the four histologic groups. RESULTS: The frequency of patients with tumors larger than 2.0 cm in size and that of patients with 200 or more ng/ml serum alpha-fetoprotein increased with the progression of histologic malignancy. Tumor staining on the angiogram, capsular formation, and extranodular invasion were never seen in groups A and B, but they began to appear in group C and increased remarkably in group D. The 5-year survival rates of the patients in groups B, C, and D were 100%, 60%, and 27%, respectively, and statistically significant differences were seen among them. In comparative evaluation of the group C patients the lesions that showed no tumor staining had no capsule, and those that had no capsule had no extranodular invasion. The 5-year survival rate of patients with wHCC without extranodular invasion (81%) was significantly higher than that of patients with extranodular invasion (35%) (p < 0.05). CONCLUSIONS: It may be recommended to provide the category of wHCC without extranodular invasion for pathologic classification of clinically early HCC (i.e., HCC of high curability).

Aged↗
PubMed1996

[Double lumen--coaxial catheter system for combined CT during arterial portography and CT hepatic angiography].

The high sensitivity of CT during arterial portography (CTAP) for hepatic lesions is accompanied with a lack of specificity for diagnosis. Combined CTAP and CT hepatic angiograpy (CTHA) had been proved to improves lesion detection and heightens confidence in interpreting perfusion abnormalities. We describe a new double lumen - coaxial catheter system for performing combined CTAP and CTHA without the need for repeated transfer of the patient or bilateral arterial punctures. This technique was employed in eight patients with liver neoplasms. In all eight patients, CTAP and CTA images were obtained successfully. We concluded that this method was useful for the evaluation of liver tumors.

Catheterization↗
PubMed1996

MR of xanthogranuloma of the choroid plexus.

We present a case of a xanthogranuloma of the lateral ventricle choroid plexus in association with focal areas of abnormal T2 signal in the tegmentum of the pons as well as within the middle cerebellar peduncles. The characteristic MR appearance of this rare entity is described along with a pathologic basis suggesting an association with posterior fossa lesions.

Adult↗
PubMed1996

[Usefulness of spiral CT in the detection of hypovascular, well-differentiated hepatocellular carcinoma].

Whole liver scanning during artery-dominant phase using spiral CT was performed in 14 patients with 17 histologically proven well-differentiated HCCs, which were not depicted by hepatic digital subtraction angiography but by CT during arterial portography. The density of HCC relative to the liver was evaluated with conventional precontrast CT, spiral CT, and following conventional CT during the equilibrium phase. Comparison between spiral CT and magnetic resonance (MR) imaging of dynamic contrast studies was also investigated. Four tumors of 17 HCCs (24%) were shown as a high-density area by the artery-dominant phase using spiral CT. Consequently, the total sensitivity of these three kinds of CT techniques was elevated to 82%. The sensitivity of dynamic MR imaging was slightly greater than that of spiral CT. However, spiral CT sometimes made the diagnosis more conspicuous by it's good spatial resolution. Our results indicate that spiral CT has a potential benefit in the detection of hypovascular well-differentiated HCC, and MR imaging and spiral CT may be complement each other.

Aged↗
PubMed1995

Endoscopic ultrasonography in diagnosis and staging of pancreatic cancer.

The accuracy of endoscopic ultrasonography (EUS) for diagnosis of pancreatic cancers was evaluated in consecutive 232 patients with possible pancreatic cancer, and that for assessment of their locoregional spread was evaluated in 28 patients with pancreatic cancer subjected to pancreatectomy, in comparison with the accuracies of transabdominal ultrasonography (US) and computed tomography (CT). EUS was found to be significantly more accurate than US or CT and was especially useful for detecting small pancreatic cancers of less than 2 cm in diameter. With EUS, pancreatic cancers could be detected as a hypoechoic mass with a relatively unclear margin and irregular internal echoes. EUS was also more sensitive than CT and US for detecting venous and gastric invasions: it was more useful for detecting direct invasion of pancreatic cancers when the tumors were less than 3 cm in diameter. These findings indicate that EUS is an accurate method for diagnosis of pancreatic cancer and assessment of their locoregional spread and is particularly useful for detecting small tumors.

Endoscopy, Digestive System↗
PubMed1995

Comparative safety and efficacy of two immune globulin products in Kawasaki disease.

OBJECTIVE: To compare the safety and efficacy of various intravenously administered immune globulin (IVGG) products in patients with Kawasaki disease. METHODS: We performed a retrospective matched-pair study of 45 pairs of patients, matched by age, gender, hospital, and illness day when IVGG therapy was initiated. All patients received aspirin, 80 to 100 mg/kg per day; one of each pair received Venoglobulin, 2 gm/kg (product A), and the other received Iveegam, 2 gm/kg (product B). Safety was assessed during and after IVGG infusion by recording rigors, pruritus, hypotension, urticaria, and nausea. Treatment efficacy was evaluated by posttreatment height and duration of fever, and subsequent echocardiographic changes. RESULTS: Untoward reactions during infusions occurred more often with product A (25%) than with product B (2%) (p < 0.025); most reactions were rigors (18% vs 2%) (p < 0.05). Therapy was completed in all patients. Height of fever and proportion of patients febrile each day after product A or B did not differ significantly. No differences were found in the frequency of coronary artery abnormalities 1 year after illness. CONCLUSIONS: No significant differences in efficacy appeared between the two IVGG products, but they differed significantly in non-life-threatening adverse reactions, especially infusion-related rigors. Other IVGG products should be evaluated in a similar fashion.

Child↗
PubMed1995

G10BP, an E1A-inducible negative regulator of Sp1, represses transcription of the rat fibronectin gene.

Downregulation of the fibronectin (FN) gene in a rat 3Y1 derivative cell line, XhoC, transformed by the adenovirus E1A and E1B genes seems to be caused by the induction of a negative regulator, G10BP, which binds to three G-rich sequences in the promoter (T. Nakamura, T. Nakajima, S. Tsunoda, S. Nakada, K. Oda, H. Tsurui, and A. Wada, J. Virol. 66:6436-6450, 1992). These are the G10 stretch and two GC boxes consisting of the G10 stretch with one internal C residue insertion. The recognition sequences of G10BP and Sp1 (GGGCGG) overlap in these GC boxes. To analyze the mechanism of the downregulation, G10BP was purified by DNA affinity chromatography, and its molecular mass was estimated to be about 30 kDa. The promoter was modified by substituting the sequence GGGG with ATCC or CTTA in these G-rich sequences, leaving the Sp1 motif intact, and by replacing the Sp1 motif by the T stretch. Transcription of FN promoter-chloramphenicol acetyltransferase fusion genes carrying the base substitution in one or more of these G-rich sequences both in vivo and in vitro revealed that the base substitution in any G-rich sequence results in reduction of promoter activity, although the downstream GC box (GCd) plays a primary role. The addition of G10BP severely inhibited the activities of the FN promoters carrying the wild-type GCd in vitro, while the promoters carrying the mutant GCd were unaffected. The binding affinity of G10BP and Sp1 to each of the G-rich sequences, analyzed by gel shift assays, indicated that G10BP binds strongly to the GCd, moderately to the G10 stretch, and weakly to GCu, while Sp1 binds strongly to GCu, moderately to GCd, and weakly to the G10 stretch. Sp1 binding to GCd and the G10 stretch was inhibited by G10BP, while binding to GCu was unaffected. These results indicate that FN gene transcription is inhibited in XhoC cells primarily by exclusion of Sp1 binding to GCd by G10BP and that G10BP is a new class of Sp1 negative regulator.

Adenovirus E1A Proteins↗
PubMed1994

[Evaluation of multislice dynamic MR imaging of the whole liver].

In 47 patients with liver cirrhosis, we performed dynamic MRI with a multisection FLASH technique that enabled us to obtain 13 T 1-weighted images of the entire liver within a single breath hold. Computed tomographic arterial portography (CTAP), US, CT, angiography (AOG) and MRI (spin echo [SE] and dynamic MRI) were performed in all 47 patients. Except for cyst, hemangioma and metastatic tumor, 104 focal nodules less than 3 cm in diameter were detected. These 104 focal lesions were divided into three groups according to the pattern of CTAP: 69 portal supply negative, 11 portal supply decreased, and 24 portal supply normal. In the portal supply negative group, 63 lesions (91%) were detected by dynamic MRI, which was superior to other modalities (US 77%, CT 41%, AOG 70%, MRI-SE 61%). The superiority of dynamic MRI resulted from its excellent ability to detect liver lesions less than 1 cm in diameter. We confirmed histologically that dynamic MRI had almost the same ability to detect hepatocellular carcinoma (HCC) as CTAP. Dynamic MRI should be clinically useful as a noninvasive examination for the detection of HCC.

Carcinoma, Hepatocellular↗
PubMed1994

Developing a new picture archiving and communication system for the new Osaka University Hospital.

Osaka University Hospital moved into a new hospital building on the suburban Suita campus in October 1993. A newly developed hospital information system, a new radiologic information system and phase I of a completely new Picture Archiving and Communication System (PACS) also began operating. Work began in 1986 on this PACS. The PACS effort has been guided by one working group and two committees during the last 7 years. A survey of the previous diagnostic and image delivery system was performed as part of the preamble to designing an optimal PACS. Extensive analysis and measurement of pre-existing operational conditions was undertaken. These studies and technical research projects are described in a companion paper in this issue. The phase I hardware installation and initial testing were completed in March 1994. Subsequent phases will build incrementally until the completely new, hospital-wide PACS is realized.

Computer Systems↗
PubMed1994

Initial data-element selection for the evaluation of picture archiving and communication system performance.

The completely new, hospital-wide picture archiving and communication system (PACS) now being implemented at Osaka University Hospital is described elsewhere in this issue. This paper lists the many studies of the department and hospital that were performed before the PACS for the purpose of identifying data elements for use in evaluating a PACS system. A second purpose of the initial data-element collection was to assist in the overall Osaka University PACS design. Selected studies from this work are presented here.

Computer Systems↗
PubMed1994

A comparison of conventional screen-film radiography and hard copy of computed radiography in full and two-thirds sizes in detection of interstitial lung disease.

This study examined whether hard-copy radiographs produced from computed radiography (CR) images show the subtle interstitial pulmonary disease equally well to conventional screen-film radiographs, because a digital radiography should be chosen for introduction of the digital picture archiving and communication system (PACS) for the new Osaka University Hospital. Eleven radiologists examined 20 abnormal and 20 control chest radiographs presented in each of three groups: conventional screen-film radiographs and two sizes of hard-copy radiographs made from CR images. This study of digital image quality of chest examinations found that some findings on conventional screen-film radiography images are not reproduced by current CR (2,000 x 2,000 x 10 bits in matrix), especially when the experienced radiologists were observed. This finding suggested improvements are needed in CR before CR of chest should fully replace conventional screen-film radiography.

Hospitals, University↗
PubMed1994

Small PACS for digital medical images--reliability and security in a clinical setting.

Recently we introduced a small Picture Archiving Communication System (PACS) for handling CT and MRI data. Our experience with this system has been useful in identifying potential problems in a clinical setting. Since the use of PACS raises both medical and social concerns, it cannot be instituted without addressing concerns related to the reliability and security issues. Although PACS is useful in the management of medical images, there are concerns about their reliability and security in a clinical setting. Reliability encompassed image quality, timeliness of the reports, and the PACS to the Radiological Information System (RIS) interface including the retrieval of the previously obtained images. The security of the patient's medical data is also essential.

Computer Security↗
PubMed1994

Comparison between conventional and spiral CT in patients with hypervascular hepatocellular carcinoma.

To determine the usefulness of spiral CT in the detection of hypervascular hepatic lesions, we compared conventional contrast enhanced CT (CECT) with whole liver dynamic scanning during the artery-dominant phase by spiral CT (SDCT), using hypervascular hepatocellular carcinoma (HCC) as a model. Twenty-nine patients with 56 hypervascular nodular type HCCs detected by hepatic digital subtraction angiography were examined by both CT techniques. These nodular type HCCs were divided into three groups according to diameter: < 10 mm (n = 7), 10-20 mm (n = 17), and over 20 mm (n = 32). None of seven lesions less than 10 mm in diameter was seen by either technique. Of 17 lesions 10-20 mm in diameter, four (24%) were detected by precontrast CT plus CECT, whereas 14 (82%) were detected by precontrast CT plus SDCT. There were no lesions detected by CECT only, whereas 10 lesions were detected by SDCT only (P < 0.01 by signed test). For 32 lesions over 20 mm in diameter, there was no significant difference in detection rates between the CT techniques. Our results indicate that spiral CT is useful for the detection of relatively small hypervascular hepatic lesions such as hypervascular HCCs.

Adult↗
PubMed1993

[Differentiation of bronchogenic carcinoma from benign nodule by MR imaging: quantitative evaluation].

To distinguish benign from malignant nodules with MR imaging, 39 pulmonary nodules (23 bronchogenic carcinomas, nine tuberculomas and seven other benign lesions) were studied. MR equipment of 1.5 Tesla was used, and relative signal intensities of pulmonary nodules on T 2- and T 1-weighted images before and after administration of gadopentate dimeglumine were evaluated. On T 2-weighted images, the relative signal intensity of bronchogenic carcinomas to subcutaneous fat was 5.48 +/- 1.69, that of tuberculomas was -2.56 +/- 2.22 and that of other benign lesions was -0.88 +/- 3.37; the difference between tuberculomas and bronchogenic carcinomas was statistically significant (p < 0.05). On T 1-weighted images before and after administration of gadopentate dimeglumine, the relative signal enhancement of bronchogenic carcinomas was 17.6 +/- 2.0, that of other benign lesions was 20.0 +/- 5.2 and that of tuberculomas was -0.0074 +/- 0.763; the difference between tuberculomas and bronchogenic carcinomas as well as benign nodules was statistically significant (p < 0.001). The relative signal intensity on T 2-weighted images and the ratio of signal enhancement to noise could differentiate tuberculomas from bronchogenic carcinomas and other benign lesions. However, bronchogenic carcinomas and other benign lesions could not be differentiated by MR imaging.

Aged↗
PubMed1993

MR imaging of oculomotor nerve neurilemmoma.

The authors present a proved case of neurilemmoma arising from the oculomotor nerve in which MR imaging, including enhancement by gadopentetate dimeglumine, dynamic study and three-dimensional gradient echo images, provided much more precise definition of the tumor.

Adult↗