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Biomedical subjects

Osamu Matsui

Publications and source records attributed to Osamu Matsui.

At least 19 recordsLinked to original sources
PubMed2006

Focal hepatic lesions mimicking cavernous hemangioma supplied by the portal vein.

We report that imaging findings of focal hepatic lesion mimicking cavernous hemangioma supplied by the portal vein, which showed delayed enhancement on CT and hyperintensity similar to that of cerebrospinal fluid on T2-weighted MR images. Biopsy specimen showed the dilated portal veins and hyperplastic change in the surrounding liver parenchyma. CT during arterial portography (CTAP), in particular single-level dynamic CTAP, could clearly depict the abnormal dilated portal vein in the lesion and facilitated the diagnosis of this condition.

Journal Article↗
PubMed2006

Anatomical study of the occipital sinus using contrast-enhanced magnetic resonance venography.

The frequency and anatomical features of the occipital sinus (OS) were analyzed in this study by contrast-enhanced magnetic resonance venography (MRV) with enhanced fast gradient echo three-dimensional (EFGRE3D) and we discuss the clinical usefulness of this method. The study included 555 patients who underwent contrast-enhanced MRV with EFGRE3D, and maximum intensity projection (MIP), multiplanar reformation (MPR) and multiprojection volume reconstruction (MPVR) images were obtained for the regions of interest. The frequency, size and communication of the OS with other vessels were assessed. The OS was identified in 209 of the 555 patients (37.7%). There were no statistically significant sex-related differences. The OS was observed less frequently in subjects younger than 50 years. Cranially and/or caudally, some OS were separated and communicated with multiple vessels. In five patients, the straight sinus (StS) communicated directly with the OS and not with the other sinuses; in two patients, the StS communicated with veins other than the OS only via small anastomotic veins. Many morphological differences in the OS can be seen. In addition, some OS function as the main drainage route of the intracranial veins instead of the transverse sinus or sigmoid sinus. In addition to MIP, detailed examination by MPR and MPVR is required for the preoperative evaluation of posterior cranial fossa lesions.

Adolescent↗
PubMed2006

Anatomical study of the confluence of the sinuses with contrast-enhanced magnetic resonance venography.

INTRODUCTION: It is important that each dural sinus can be recognized during brain surgery and that the venous route can be used for interventional procedures. In this study, the anatomical features and patterns of the confluence of the sinuses were analyzed. METHODS: The technique of contrast-enhanced three-dimensional magnetic resonance venography was used in 549 patients. RESULTS: There were many anatomical variations in the confluence of the sinuses. Most cases had wide communication between the right and left transverse sinuses. CONCLUSION: Careful examination of the confluence of the sinuses is essential for the preoperative evaluation of posterior cranial fossa lesions and interventional procedures using the venous route.

Adolescent↗
PubMed2006

Computerized methods for determining respiratory phase on dynamic chest radiographs obtained by a dynamic flat-panel detector (FPD) system.

Chest radiography using a dynamic flat-panel detector with a large field of view can provide sequential chest radiographs during respiration. These images provide information regarding respiratory kinetics, which is effective for diagnosis of pulmonary diseases. For valid analysis of respiratory kinetics in diagnosis of pulmonary diseases, it is crucial to determine the association between the kinetics and respiratory phase. We developed four methods to determine the respiratory phase based on image information associated with respiration and compared the results in dynamic chest radiographs of 37 subjects. Here, the properties of each method and future tasks are discussed. The method based on the change in size of the lung gave the most stable results, and that based on the change in distance from the lung apex to the diaphragm was the most promising method for determining the respiratory phase.

Humans↗
PubMed2006

Autoimmune pancreatitis with multifocal mass lesions.

Autoimmune pancreatitis (AIP) is radiologically characterized as diffuse swelling of the pancreatic parenchyma and irregular narrowing of the pancreatic ducts. We present a case of AIP with multiple small nodular lesions in the pancreas. This case suggests that AIP with only small nodular or localized lesions is more difficult to differentiate from pancreatic cancer than typical cases of AIP.

Autoimmune Diseases↗
PubMed2006

Pathologic and biological assessment of lung tumors showing ground-glass opacity.

BACKGROUND: We evaluated the pathologic and biological aspects of lung tumors 3.0 cm or less in diameter with the appearance of ground-glass opacity (GGO). METHODS: Of 988 patients with non-small cell lung cancer who underwent operations at our institute between January 1994 and December 2004, 87 resected lung tumor specimens that showed GGO appearance on helical computed tomography were obtained from 81 patients. Forty-four lesions were pure GGO with no solid component in the tumor and 43 lesions were mixed GGO consisting of areas of attenuation with a solid component. Together with histological features, MIB1 and nm23 expression within tumors were examined immunohistochemically. RESULTS: The mean tumor size in the pure GGO group was significantly smaller than that in the mixed GGO group. The composition of pathologic subtypes and biological characteristics were clearly different between the two groups. Although atypical adenomatous hyperplasia and localized bronchioloalveolar cell carcinoma of Noguchi's A and B were the predominant pathologic subtypes and nm23 negativity was rare in the pure GGO group, a high score for expression of MIB1 was often found in pure GGO tumors even though the tumors were less than 10 mm in diameter. CONCLUSIONS: If the tumor is 2 cm or less in diameter, the ability of invasion and metastasis seems to be low in pure GGO tumors. However, the proliferation ability of these tumors suggests the necessity of a careful follow-up schedule if the tumor is greater than 5 mm in diameter. For mixed GGO tumors, surgical resection instead of observation is justified.

Carcinoma, Non-Small-Cell Lung↗
PubMed2006

Evaluation of pulmonary function using breathing chest radiography with a dynamic flat panel detector: primary results in pulmonary diseases.

OBJECTIVES: Dynamic flat panel detectors (FPD) permit acquisition of distortion-free radiographs with a large field of view and high image quality. The present study was performed to evaluate pulmonary function using breathing chest radiography with a dynamic FPD. We report primary results of a clinical study and computer algorithm for quantifying and visualizing relative local pulmonary airflow. MATERIALS AND METHODS: Dynamic chest radiographs of 18 subjects (1 emphysema, 2 asthma, 4 interstitial pneumonia, 1 pulmonary nodule, and 10 normal controls) were obtained during respiration using an FPD system. We measured respiratory changes in distance from the lung apex to the diaphragm (DLD) and pixel values in each lung area. Subsequently, the interframe differences (D-frame) and difference values between maximum inspiratory and expiratory phases (D-max) were calculated. D-max in each lung represents relative vital capacity (VC) and regional D-frames represent pulmonary airflow in each local area. D-frames were superimposed on dynamic chest radiographs in the form of color display (fusion images). The results obtained using our methods were compared with findings on computed tomography (CT) images and pulmonary functional test (PFT), which were examined before inclusion in the study. RESULTS: In normal subjects, the D-frames were distributed symmetrically in both lungs throughout all respiratory phases. However, subjects with pulmonary diseases showed D-frame distribution patterns that differed from the normal pattern. In subjects with air trapping, there were some areas with D-frames near zero indicated as colorless areas on fusion images. These areas also corresponded to the areas showing air trapping on computed tomography images. In asthma, obstructive abnormality was indicated by areas continuously showing D-frame near zero in the upper lung. Patients with interstitial pneumonia commonly showed fusion images with an uneven color distribution accompanied by increased D-frames in the area identified as normal on computed tomography images. Furthermore, measurement of DLD was very effective for evaluating diaphragmatic kinetics. CONCLUSIONS: This is a rapid and simple method for evaluation of respiratory kinetics for pulmonary diseases, which can reveal abnormalities in diaphragmatic kinetics and regional lung ventilation. Furthermore, quantification and visualization of respiratory kinetics is useful as an aid in interpreting dynamic chest radiographs.

Adult↗
PubMed2006

Peliosis hepatis: spectrum of imaging findings.

OBJECTIVE: It is important to recognize the imaging characteristics of peliosis hepatis because peliotic lesions may mimic several different types of focal hepatic lesions CONCLUSION: We illustrate the spectrum of imaging findings of peliosis hepatis, including sonography, CT, MR, and angiography.

Adult↗
PubMed2005

Automated image-matching technique for comparative diagnosis of the liver on CT examination.

When interpreting enhanced computer tomography (CT) images of the upper abdomen, radiologists visually select a set of images of the same anatomical positions from two or more CT image series (i.e., non-enhanced and contrast-enhanced CT images at arterial and delayed phase) to depict and to characterize any abnormalities. The same process is also necessary to create subtraction images by computer. We have developed an automated image selection system using a template-matching technique that allows the recognition of image sets at the same anatomical position from two CT image series. Using the template-matching technique, we compared several anatomical structures in each CT image at the same anatomical position. As the position of the liver may shift according to respiratory movement, not only the shape of the liver but also the gallbladder and other prominent structures included in the CT images were compared to allow appropriate selection of a set of CT images. This novel technique was applied in 11 upper abdominal CT examinations. In CT images with a slice thickness of 7.0 or 7.5 mm, the percentage of image sets selected correctly by the automated procedure was 86.6+/-15.3% per case. In CT images with a slice thickness of 1.25 mm, the percentages of correct selection of image sets by the automated procedure were 79.4+/-12.4% (non-enhanced and arterial-phase CT images) and 86.4+/-10.1% (arterial- and delayed-phase CT images). This automated method is useful for assisting in interpreting CT images and in creating digital subtraction images.

Aged↗
PubMed2005

Arterial blood supply to the posterior aspect of segment IV of the liver from the caudate branch: demonstration at CT after iodized oil injection.

PURPOSE: To retrospectively evaluate the arterial blood supply to the posterior aspect of segment IV of the liver with computed tomography (CT) after transcatheter arterial chemoembolization (TACE) with iodized oil through the caudate arterial branch of the liver for treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Institutional review board approval and patient informed consent were not required for this retrospective study. Twenty-four patients (11 men and 13 women; mean age, 68 years) with HCC originating in the caudate lobe (n = 23) or posterior aspect of segment IV (n = 1) were selected. TACE of the caudate arterial branch was performed in all patients, including one patient with HCC in the posterior aspect of segment IV who underwent TACE of the caudate arterial branch after CT helped confirm that iodized oil was not distributed in the tumor after TACE of the medial segmental artery. The distribution of iodized oil in the posterior aspect of segment IV was analyzed with CT 1 week after TACE. The number and origin of all arteries supplying the caudate lobe and the number of arteries embolized were determined. RESULTS: Thirty-three caudate arterial branches were embolized. Twenty-nine branches were derived from the right hepatic artery and four were derived from the left hepatic artery. A single branch was seen in 17 patients, two branches were seen in five, and three branches were seen in two. Eight patients simultaneously underwent additional TACE of branches of the right hepatic artery (n = 6) or right inferior phrenic artery (n = 2). At CT, iodized oil was seen to be distributed entirely (n = 19) or partially (n = 5) in the caudate lobe. Distribution of iodized oil at the posterior aspect of segment IV was observed in 16 patients (67%), including 13 (54%) whose caudate arterial branches were derived entirely from the right hepatic artery. CONCLUSION: The results of this study suggest that the caudate arterial branch, which is mainly derived from the right hepatic artery, frequently supplies the posterior aspect of segment IV. This knowledge is important for managing HCC in the posterior aspect of segment IV by means of TACE.

Aged↗
PubMed2005

Dynamic MR imaging for diagnosis of lesions adjacent to pituitary gland.

In this study, we evaluated the usefulness of dynamic studies for the preoperative diagnosis of tumor lesions adjacent to the pituitary gland. We examined 13 tumors. We obtained pre- and post-contrast thin slice T1-weighted images of the sellar regions. FSE sequences were used for dynamic study. The capability to distinguish the tumor from the pituitary gland and additional information obtained from the dynamic study were evaluated. Two meningiomas were identified more clearly on the dynamic than on the delayed study. In two cavernous hemangiomas, the peripheral nodular stains gradually increased during the dynamic study. For the preoperative evaluation of lesions adjacent to the pituitary gland, the dynamic study can often identify the lesions more clearly and may provide additional information.

Adult↗
PubMed2005

CT arteriography for orbital tumors: diagnostic and surgical value.

The aim of this study is to investigate the efficacy of dynamic computed tomography (CT) during selective angiography (CT-arteriography) of orbital tumors in the evaluation of intratumoral vascular anatomy, feeding artery territory, and histological diagnosis. Among 35 consecutive cases with various orbital lesions, those cases showing tumor staining or pooling of the contrast medium on digital subtraction angiography (DSA) were evaluated by CT-arteriography (n = 14). The information obtained by CT-arteriography was compared with that provided by enhanced MRI (n = 31) and dynamic MRI (n = 21), in which the contrast medium was injected intravenously. In addition to the visualization of fine vascular anatomy, CT-arteriography emphasized areas of nodular enhancement and non-enhancing cystic/necrotic components as well as the intratumoral feeding arteries. Patterns of CT-arteriography were categorized into three subgroups: homogeneous enhancement (benign lymphoid lesion), partial enhancement (schwannomas and carcinomas), and patchy multinodular enhancement (specific for cavernous angiomas). In addition, CT-arteriography with selective arterial catheterization clearly delineated the feeding artery territories. CT-arteriography, with a minimal dose of contrast medium, can offer significant advantages over intravenously injected dynamic neuroimaging, and provides additional valuable preoperative information about the orbital tumor under investigation.

Adult↗
PubMed2005

Detection and characterization of hepatocellular carcinoma by imaging.

In cirrhotic livers, several types of hepatocellular nodules are found during the diagnosis of hepatocellular carcinoma (HCC). To characterize the nodules is imperative for the optimal management of cirrhotic patients. However, the definitive distinction between early stage, well-differentiated HCC and borderline lesions is still difficult because histologic differences among these nodules are sequential. Therefore, it is important to appreciate the changes on imaging with the progression from benign precancerous nodule to overt HCC and to predict the prognosis of the nodules on the basis of these imaging findings.

Angiography↗
PubMed2005

Cirrhotic nodules: association between MR imaging signal intensity and intranodular blood supply.

PURPOSE: To retrospectively determine whether there is a relationship between the intranodular blood supply evaluated at computed tomography (CT) during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) and the magnetic resonance (MR) imaging signal intensity of nodules associated with cirrhosis. MATERIALS AND METHODS: Neither institutional review board approval nor informed consent was required for retrospective reviews of medical records and images. One hundred fourteen hepatocellular nodules 10 mm or greater in largest diameter in 58 patients (39 men, 19 women; mean age, 61 years) with cirrhosis were evaluated at CTAP, CTHA, and MR imaging. The CTAP and CTHA nodule findings were divided into three main types: Type A nodules were isoattenuating at CTAP and hypoattenuating at CTHA; type B nodules, slightly hypoattenuating at CTAP and hypoattenuating at CTHA; and type C nodules, strongly hypoattenuating at CTAP and hyperattenuating at CTHA. The relationships between the CTAP and CTHA findings and the MR imaging signal intensity among these nodules were analyzed by using the chi(2) test. RESULTS: On T1-weighted MR images, 27 (63%) of 43 type A nodules were hyperintense, nine (39%) of 23 type B nodules were isointense, and 19 (48%) of 40 type C nodules were hypointense; differences were not significant. On T2-weighted MR images, 31 (72%) of 43 type A nodules were hypointense (P < .05), 12 (52%) of 23 type B nodules were isointense, and 34 (85%) of 40 type C nodules were hyperintense (P < .05). CONCLUSION: There was a significant association between intranodular blood supply and nodule signal intensity on T2-weighted MR images. However, study findings did not show whether the blood itself (ie, blood volume or blood flow amount) directly influenced the signal intensity.

Adult↗
PubMed2005

Flocculating activity of cross-linked poly-gamma-glutamic acid against bentonite and Escherichia coli suspension pretreated with FeCl3 and its interaction with Fe3+.

Cross-linked poly-gamma-glutamic acid (C-L gamma-PGA) at 5 microg/ml flocculated bentonite suspension pretreated with polyaluminum chloride (PAC) at 2 microg/ml Al3+-PAC to a transparency of approximately 30% after 30 min and more than 90% after 4 h, while Al3+ concentration in the upper phase of the suspension decreased with incubation time. When pretreated with FeCl3 at 16 microg/ml Fe3+-FeCl3, similar results were obtained. In the case of Escherichia coli suspension, the combination of C-L gamma-PGA and FeCl3 demonstrated a more marked flocculating activity with a satisfactory transparency occurring after 30 min of treatment, accompanied by a decrease in residual Fe3+ concentration. In the above two suspensions pretreated with FeCl3, small visible floats appeared in the early stage of incubation. These floats were found to be due to the direct interaction between FeCl3 and C-L gamma-PGA, indicating the formation of a water-insoluble complex. After allowing the suspension to stand for a long time, elemental analysis and inductively coupled plasma spectroscopy of the precipitates produced suggested that not only the complex was formed due to the interaction between Fe3+ in FeCl3 and COO- in the C-L gamma-PGA molecule, but also Fe2O3 and Fe(OH)3 might be entrapped in this complex. This could be applied to scavenge metal ions including Fe3+ from polluted water.

Bentonite↗