Biomedical subjects

N Hashiguchi

Publications and source records attributed to N Hashiguchi.

46 records · Page 3Linked to original sources

PubMedDate not supplied

Influence of copper on MRI of hepatocellular carcinoma.

The purpose of this paper is to clarify whether copper accumulation in hepatocellular carcinoma (HCC) is a cause of high intensity signal pattern on T1-weighted images (T1-WI) by comparing the histologically proven copper accumulation with MR images. Forty-five surgically resected HCCs were analyzed. Distribution patterns of divalent copper by a modified Timm's method on their maximum cut surfaces were compared with signal patterns on corresponding T1-WI. The degree of copper accumulation in tumor compared with surrounding liver tissue was higher in 6 lesions, equal in 17 lesions, and lower in 22 lesions. High intensity pattern on T1-WI were observed in 3 of 6 lesions (50%), 10 of 17 lesions (59%), and 10 of 22 lesions (45%). Distribution patterns of copper were not correlated with intensity patterns on T1-WI. We conclude that the paramagnetic effect of divalent copper accumulation in HCC is insufficient to influence the MRI.

Aged↗

PubMedDate not supplied

Radiologically identifiable intratumoral portal vein in intrahepatic cholangiomas: a diagnostic pitfall.

BACKGROUND: Although intratumoral patent portal vein (ITPV) is one of the characteristic features of benign hepatic lesions, ITPVs can be demonstrated in malignant tumors. We present the spectrum of MR and CT findings of ITPV identified in intrahepatic cholangiomas with pathological correlations. METHODS: The ultrasound, CT and/or MRI findings of pathologically-confirmed intrahepatic cholangiomas were reviewed and correlated with surgical specimen or autopsy findings. RESULTS: Intratumoral patent vessels were radiographically-demonstrated in 5 patients with intrahepatic cholangiomas. All intratumoral vessels were secondary or tertiary order portal vein branches. Some wall thickening was identified on pathological examinations. CONCLUSION: The radiological demonstration of intratumoral portal vein is not a specific sign of benignity. In the case of a hepatic tumor with a patent portal tract, cholangioma should be considered, as well as benign tumors or lymphoma.

Adenoma, Bile Duct↗

PubMedDate not supplied

Helical CT imaging of bronchial arteries with curved reformation technique in comparison with selective bronchial arteriography: preliminary report.

PURPOSE: Our goal was to evaluate the ability of helical CT to identify and demonstrate the origins and courses of bronchial arteries, using the curved reformation technique, in patients undergoing bronchial arterial interventional procedures. METHODS: Thin section helical CT was performed on seven patients before bronchial arterial interventional procedures. The curved reformation technique was used to demonstrate the origins and continuous vessel tracing of bronchial arteries and compared with bronchial arteriographic findings. RESULTS: In all, 16 bronchial arteries were evaluated, 8 on the right and 8 on the left. The origins of 12 bronchial arteries were identified. In the demonstration of tracing vessels, seven right bronchial arteries and three left were classified as excellent or fair. CONCLUSION: Helical CT imaging with the curved reformation technique is helpful in identifying bronchial arteries, especially on the right, in patients with indications for bronchial arterial interventional procedures.

Adult↗

PubMedDate not supplied

Patterns of peripheral enhancement in breast masses: correlation of findings on contrast medium enhanced MRI with histologic features and tumor angiogenesis.

PURPOSE: Our goal was to review patterns of peripheral enhancement on contrast-enhanced MRI of the breast and to correlate radiologic findings with pathologic features. METHOD: We reviewed the MR images of 124 consecutive women with breast lesions. Peripheral enhancement was identified in 35 (32 malignant, 3 benign) lesions. MRI findings were correlated with pathologic features including microvessel density and distribution determined histologically. RESULTS: Early peripheral enhancement with centripetal progression was seen in invasive carcinomas with a high peripheral and a low central microvessel density, associated with fibrosis and/or necrosis (n = 18; 15 with central fibrosis, 2 with fibrosis and necrosis, and 1 with necrosis alone). Early peripheral enhancement with minimal or no change in enhancement was seen in both malignant (n = 10) and benign (n = 3) lesions. Delayed peripheral enhancement with centrifugal progression was seen in carcinomas that had an expansive growth pattern and a high marginal vessel density with or without a vascularized rim of connective tissue (n = 4). CONCLUSION: Early peripheral enhancement with centripetal progression appears to be fairly specific for carcinomas, whereas early enhancement with minimal or no centripetal progression, although more common in malignant tumors, may be seen in some benign lesions as well.

Adult↗

PubMedDate not supplied

Bronchogenic carcinoma invasion of the chest wall: evaluation with dynamic cine MRI during breathing.

PURPOSE: Our goal was to assess the utility of breathing dynamic cine MR (BDCMR) in the evaluation of tumor invasion to the chest wall in bronchogenic carcinomas. METHOD: BDCMR imaging was performed preoperatively in 25 patients with bronchogenic carcinomas adjacent to the chest wall. Twelve sequential images were obtained in the same coronal and/or sagittal planes during one respiratory cycle with fast spoiled GRASS sequence, and analysis with cine-loop display was performed. RESULTS: In all 14 cases in which free movement of tumor along the parietal pleura on BDCMR was demonstrated, no chest wall invasion was evident at thoracotomy. However, of 11 patients with fixation of the tumor on BDCMR, 5 had benign pleural adhesions, 5 had chest wall invasion at thoracotomy, and 1 with an apical tumor had no benign pleural adhesion or chest wall invasion. CONCLUSION: Although BDCMR cannot distinguish benign pleural adhesions from chest wall invasion by tumor, this method accurately estimated the free movement of lung tumors with no invasion of chest wall from bronchogenic carcinomas prior to surgery.

Aged↗

PubMedDate not supplied

High-resolution CT characteristics of poorly differentiated adenocarcinoma of the peripheral lung: comparison with well differentiated adenocarcinoma.

OBJECTIVE: The purpose of this study was to elucidate the characteristic high-resolution CT (HRCT) findings of poorly differentiated adenocarcinoma (PDA) in comparison with those of well differentiated adenocarcinoma (WDA). MATERIALS AND METHODS: We investigated the HRCT features of surgically resected PDAs (n=21) and WDAs (n=31). We analyzed the margin, CT attenuation, and internal architecture of the tumor and findings in the surrounding lung field, comparing them with the corresponding pathologic findings. RESULTS: Smoothness of the greater part (full-1/2 round) of the tumor and solid appearance were more prevalent in PDAs than WDAs (81% vs. 32%, 100% vs. 35%) [p<0.01]. Air-bronchogram was prevalent in WDAs (58%), but was never seen in PDAs [p<0.01]. Ground-glass opacity in PDAs pathologically corresponded to inflammation and edema in the alveolar space. CONCLUSIONS: Smoothness of the tumor margin and solid appearance without air-bronchogram were more commonly found in PDA than in WDA. HRCT may predict the histological differentiation of adenocarcinoma in selected cases in which differentiation is inconclusive by sputum cytology and transbronchial or CT-guided biopsy.

Adenocarcinoma↗

PubMedDate not supplied

Intra-arterial digital subtraction angiography with extra-large fields using a computed radiography system in evaluating peripheral vascular disease.

The authors evaluated the usefulness of intra-arterial digital subtraction angiography (DSA) with extra-large field sizes using a computed radiography (CR) system in evaluating peripheral vascular disease (PVD). Intra-arterial DSA using CR was performed in 55 patients with suspected PVD. A 4 F catheter was advanced into the abdominal aorta via the transbrachial approach and 90 ml of contrast medium was injected during six exposures using a long leg changer mounting a total of 18 imaging plates on six surfaces. Visualization of the superficial femoral and popliteal arteries was judged as diagnostic in all cases. The abdominal aorta, iliac arteries, and subtrifurcation were also visualized in most cases, but visualization was suboptimal in some cases. As a complication, median nerve palsy occurred in one case. This technique is thought to be a useful method for evaluating PVD because of the advantages of a large field of view and wide exposure latitude, in spite of its relatively long processing time.

Aged↗

PubMedDate not supplied

Neural network analysis of breast cancer from MRI findings.

PURPOSE: To evaluate how much the experience of radiologists affects the performance of an artificial neural network (ANN) trained by two highly experienced radiologists. MATERIALS AND METHODS: Before biopsy two experienced radiologists reviewed the MR images of 100 adult patients with suspicious breast lesions and evaluated their findings based on six features. This database was then used to train a three-layered feed-forward neural network. The network's generalizing ability was then tested to predict the outcome of biopsy in 56 new patients' records which were extracted by 10 participating radiologists. The MRI findings of each reader were presented to the ANN to evaluate the effect of various levels of experience on the output of the ANN. The performance of the ANN was then compared with that of attendant physicians in terms of sensitivity, specificity, and accuracy as well as ROC analysis. RESULTS: The best ANN outcome offered a correct diagnosis in 40 of 41 of the patients with malignant breast cancer and 10 of 15 with benign entity presented in the testing set. The output of the trained ANN outperformed the attendant radiologists with low levels of experience and showed comparable performance with radiologists with higher levels of experience. CONCLUSIONS: The ANN is able to work as a backup system to assist radiologists in the diagnosis of breast cancer.

Adolescent↗

PubMedDate not supplied

[Relationship between the experience of steroids side effects and noncompliance with oral steroids treatment in collagen disease patients].

PURPOSE: To analyze the relationship between the experience of side effect and the compliance with oral steroids drug treatment of the patients in Collagen Disease Clinic. METHODS: A questionnaire survey through interview was conducted on 165 outpatients with various collagen disease at Saga Medical School Hospital. RESULTS: 94 patients (57%) had a history of noncompliance to the steroids drug. 49 patients (52.1%) adventitiously had forgotten to take the steroids as ordered and 45 patients (47.9%) intentionally had regulated their steroids dose or had discontinued the steroids drug treatment. Over 80% of the patients had experienced side effects of the steroids. The patients who experienced one or more of the following side effects, osteoporosis, bone fractures, menstrual disorders, moon face, central obesity, alopecia, acnelike eruption, manic-depressive state, and insomnia, intentionally regulated, or discontinued the steroids therapy. In addition, the patients who were not made cognizance about side effects of the steroids by their physicians and nurse tended to noncompliance group. CONCLUSION: To increase the compliance rate with oral steroids drug treatment, we must make conscious efforts to inform the patients on the condition of their medical states, the efficacy of the prescribed drugs, and the side effects and risk concerning discontinuation of the steroids. It is Also necessary to establish "Drug information and counseling day" in outpatient Department.

Anti-Inflammatory Agents↗

PubMedDate not supplied

Adaptive spatial filtering technique for storage phosphor radiography in portable chest radiographs: parameter optimization.

PURPOSE: To investigate the optimal parameters of adaptive spatial filtering (ASF) in storage phosphor radiography for processing portable chest radiographs. MATERIALS AND METHODS: Two types of weighting factor curves starting at 383 digital pixel values (PV) (type B) and at 511 PV (type C) were selected for the optimization of ASF. The PV of 27 areas of apparent pulmonary lesions and seven retrocardiac areas were measured for original unprocessed and ASF-processed images. Three radiologists compared 30 ASF-processed portable chest radiographs with apparent pulmonary or pleural lesions with unprocessed images. RESULTS: PV measurements revealed no significant change in pulmonary densities in type B, and an increase in PV of lower pulmonary densities in type C. Densities of retrocardiac areas were more enhanced in type C than in type B. Observer testing showed that pulmonary densities were evaluated as unchanged in 90% of type B images and 76% of type C images. Changes in mediastinal densities were evaluated as adequate in 80% of type B and 90% of type C images. CONCLUSION: The starting point of the weighting factor curve of ASF in portable chest radiographs should be set the same as in chest radiographs in the upright posteroanterior position with high kVp.

Algorithms↗