Biomedical subjects

T Kozuka

Publications and source records attributed to T Kozuka.

At least 451 records · Page 25Linked to original sources

PubMedDate not supplied

Computed tomographic myelography characteristics of spinal cord atrophy in juvenile muscular atrophy of the upper extremity.

Although atrophy of the lower cervical and upper thoracic cord in juvenile muscular atrophy of distal upper extremity has been reported, the atrophic patterns of the cord, especially in the transverse section, have not been studied extensively. The aim of this study is to clarify the atrophic patterns of the cord by CT myelography (CTM) and to discuss the pathogenesis of cord atrophy. Sixteen patients with juvenile muscular atrophy of distal upper extremity were examined by CTM. Atrophy of the lower cervical and upper thoracic cord, consistent with the segmental weakness, was seen in all patients. Flattening of the ventral convexity was a characteristic atrophic pattern of the cord. Bilateral cord atrophy was commonly observed; eight of 12 patients with unilateral clinical form and all four patients with bilateral form showed bilateral cord atrophy with dominance on the clinical side. There was no correlation between the degree of cord atrophy and duration of symptoms. Flattening of the ventral convexity, associated with purely motor disturbances, reflects selective atrophy of the anterior horns in the cord, which is attributable to chronic ischemia. Cord atrophy proved to precede clinical manifestations. The characteristic atrophy of the cord provides useful information to confirm the diagnosis without long-term observation.

Adolescent↗

PubMedDate not supplied

Head and neck carcinoma: detection of extraorgan spread with MR imaging and CT.

A retrospective analysis of the Magnetic resonance (MR) and CT findings in 18 untreated carcinomas of the oral cavity (7), oropharynx (2), hypopharynx (7), and larynx (2) was performed to assess the accuracy in evaluating extraorgan tumor spread and nodal involvement. Surgical and pathologic correlation was available for 13 primary tumors and nodal status was analyzed in 18. Nine primary tumors had extraorgan extension. MR had a tendency to be superior to CT in predicting tumor invasion of the cartilage and muscle. Sensitivity, specificity and accuracy for extraorgan spread of primary tumors were 89%, 100% and 92%, respectively, for MR and 78%, 75% and 77% for CT. Accuracy for nodal classification (83%) and carotid invasion (94%) of MR was equal to that of CT. CT was more sensitive than MR for demonstrating necrosis within the nodes and vice versa for detecting retropharyngeal nodes. MR imaging is a useful radiologic modality in evaluating extraorgan tumor spread and nodal levels of the head and neck carcinomas.

Adult↗

PubMedDate not supplied

Inclined coronal scans in thoracic MR imaging.

To determine the value of inclined coronal MR in diagnosing thoracic abnormalities, the multiscan coronal and inclined coronal spin echo MR images of 4 normal subjects and 10 patients with thoracic abnormalities were reviewed. The major airway such as trachea, main bronchi and lobar bronchi, left atrium and its junctions with pulmonary veins required less slices for visualization on inclined coronal images than on standard coronal images, and these normal structures and the lesions located in this region were easy to evaluate in several cases. The left pulmonary artery, especially the upper and lower lobe branches were better visualized on inclined coronal images. The pericardium and the other great vessels were equally visualized on inclined and on standard coronal images. There was no case in which normal structures or lesions were more difficult to demonstrate on inclined coronal images compared with standard coronal images. We conclude that an inclined coronal MR scan of the thorax is valuable to evaluate the mediastinal structures and lesions, especially in diagnosing the abnormalities of the airway, left atrium and its junctions with pulmonary veins.

Adult↗

PubMedDate not supplied

Retroperitoneal schwannomas simulating adrenal tumors.

Tumors in the area of the adrenal were detected by chance in two patients who underwent a regular physical check-up. On arteriography the tumors were found to be fed by the adrenal artery. The diagnosis was retroperitoneal schwannoma, but in both patients it was difficult to differentiate the schwannoma from an adrenal tumor preoperatively.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

HIS/RIS contribution to image diagnosis and maximization of efficacy of PACS when coupled with HIS/RIS.

To maximize the efficacy of the PACS coupled with the HIS/RIS and to clarify the effectiveness of the PACS itself, the amount of contribution of the HIS/NS to image diagnosis was measured beforehand. Video-tape recorders were used to record the CRT display of the HIS/RIS terminals and the simultaneous conversation between a patient and his physician in the clinics of our hospital. Consultation time and entry time for image examination order were measured for each case by replay of the tape. Consultation time was approximately 10 min, while order time was 2-3.5 min depending on whether the physician was an internist or an orthopedist. Detailed description on an order was closely related to detailed reports. The HIS/RIS contributed to image diagnosis even before the PACS was coupled. Concrete methods of efficacy maximization of the PACS were pointed out by internists and orthopedists in terms of modalities, outpatient clinics and wards.

Ambulatory Care Facilities↗

PubMedDate not supplied

Three dimensional imaging of tracheobronchial system using spiral CT.

The purpose of this study was to evaluate the clinical efficacy of 3D reconstruction of the tracheobronchial system using spiral CT. A total of 25 patients with tracheobronchial abnormalities, stenosis (n = 21) and fistula with esophagus (n = 4), underwent a single breathhold spiral CT (5 mm collision, 5 mm)/s increment). With respect to localization, extent and degree of stenosis and size of fistula were compared with findings at bronchoscopy. The CT location and extent of stenoses were consistent with bronchoscopic findings in all 21 patients. The diameter and shape of the lesions were not evaluated in five patients with severe stenoses. In patients with fistula, 3D CT image demonstrates the location and size of fistula in all four patients. Spiral CT serves to demonstrate accurate and useful 3D reconstruction images for planning and monitoring therapy.

Adult↗

PubMedDate not supplied

High-dose chemotherapy with hematopoietic stem cell transplantation is effective for nasal and nasal-type CD56+ natural killer cell lymphomas.

CD56+ natural killer (NK) cell lymphomas occur frequently in the nasal and nasopharyngeal regions and carry a poor prognosis. We have studied seven cases with NK-cell lymphomas. These lymphomas showed the following immunophenotype: CD56+, CD2+, sCD3- and Epstein-Barr virus-encoded small RNAs (EBERs)+. Six patients had localized (stage I or II) disease involving the nasopharyngeal region, while one had stage III disease. One patient with stage I disease achieved a complete remission (CR) after treatment with involved-field irradiation, but subsequently relapsed and died. The remaining six patients received combination chemotherapy as primary treatment: five patients with localized stage I or II disease and one patient with advanced stage III disease. Responses to initial chemotherapy were generally poor. These six patients received a variety of salvage chemotherapy regimens, but never achieved a CR. Subsequently, four of six patients showed a highly aggressive clinical course and died of disseminated disease within 1 year from the diagnosis. Three of six patients received high-dose chemotherapy supported by syngeneic, autologous or allogeneic peripheral blood stem cell transplantation. Two of the three transplant patients achieved a CR and are now surviving in continuous CR. Our clinical experience suggests that myeloablative high-dose chemotherapy and bone marrow rescue by hematopoietic stem cell transplantation may be an effective salvage treatment modality for refractory NK-cell lymphomas and could be considered as a part of the initial therapy for these patients.

Adolescent↗

PubMedDate not supplied

MR imaging of primary thyroid lymphoma.

Magnetic resonance (MR) images of a patient with primary malignant lymphoma of the thyroid gland and Hashimoto thyroiditis are presented. On T1-weighted images the intensity of the thyroid lymphoma was similar to that of Hashimoto thyroiditis. On T2-weighted images the thyroid lymphoma was seen as a homogeneous area of high intensity compared with Hashimoto thyroiditis. Magnetic resonance was equal to CT in diagnosing and staging of primary thyroid lymphoma. Direct coronal images of MR were useful in planning the radiation port.

Aged↗

PubMedDate not supplied

Mediastinal lymph node metastases from nonsmall cell bronchogenic carcinoma: reevaluation with CT.

We evaluated the sensitivity of CT for detecting mediastinal lymph node metastases in patients with nonsmall cell bronchogenic carcinoma. Computed tomography of 208 cases of surgically proven bronchogenic carcinoma from three institutes was evaluated retrospectively using specific diagnostic criteria. These consisted of two size thresholds for specific mediastinal node regions: 13 mm short transverse diameter for nodes in the subcarinal, precarinal, and tracheobronchial regions and 10 mm for other regions. Based on these criteria, the overall sensitivity of CT was 69%, specificity 94%, and accuracy 86% for detection of metastasis. In cases of adenocarcinoma, sensitivity was 61%, specificity 93%, and accuracy 81%, and in those of squamous cell carcinoma the respective values were 86, 94, and 92%. Comparison between the results using the present criteria with the former criterion of 10 mm short transverse diameter for all mediastinal nodes revealed that the number of false-positive cases decreased markedly. We conclude that more accurate CT evaluation of mediastinal lymph node metastasis in nonsmall cell bronchogenic carcinoma can be achieved with specific size criteria for specific mediastinal regions.

Adenocarcinoma↗

PubMedDate not supplied

MR imaging of Sjögren syndrome: correlation with sialography and pathology.

Magnetic resonance (MR) imaging of the parotid glands were performed in 13 cases of Sjögren syndrome to assess if there are any typical MR features. The MR findings were compared with sialography and pathology results. Signal intensity ratios of parotid (minus background noise) to skeletal muscle (minus background noise) were measured in these 13 cases as well as in 10 normal controls. Both T1- and T2-weighted images showed multiple hypointense mixed with hyperintense foci (salt-and-pepper appearance) throughout the glands in the six Sjögren cases of intermediate severity (46%), inhomogeneous glands in five cases with early or advanced disease, and homogeneous glands in the remaining two cases with the earliest stage of disease. Mean intensity ratios in T2-weighted pulse sequences in patients with salt-and-pepper appearance and inhomogeneous glands were significantly smaller than those in normal controls (p less than 0.05 and p less than 0.001, respectively). Pathologic studies tend to indicate that focal lymphocytic aggregates associated with increased interlobular fibrosis are probably responsible for the hypointense foci and the decrease in intensity ratios. We think that the salt-and-pepper appearance is suggestive of Sjögren syndrome and that the decreased intensity ratios combined with a typical clinical picture may lead to a highly probable diagnosis of this disorder.

Adult↗

PubMedDate not supplied

Siderotic nodules in hepatic cirrhosis disappearing after biliary hemorrhage: MR imaging.

Magnetic resonance demonstrated siderotic regenerating nodules in a patient with hepatocellular carcinoma with accompanying liver cirrhosis. The siderosis disappeared when iron deficiency anemia developed in association with biliary hemorrhage. Magnetic resonance was sensitive enough to follow changes in the siderosis. The mechanism of iron deposition in regenerating nodules that accompanied liver cirrhosis did not seem to be related to the severity of the liver damage.

Anemia, Hypochromic↗

PubMedDate not supplied

Differentiation between hepatoma and hemangioma with inversion-recovery snapshot FLASH MRI and Gd-DTPA.

Thirty-eight patients with focal liver tumors (20 hepatomas, 18 hemangiomas) were studied by dynamic sequential inversion recovery (IR) snapshot fast low angle shot (FLASH) MR imaging with Gd-DTPA. Immediately after 0.05 mmol/kg Gd-DTPA was administered intravenously for 2-3 s followed by flushing with normal saline for 4-5 s, 10 images were obtained in the first 20 s (time zero is the end of flush, early phase). Then, one image every 30 s from 1 to 3 min (late phase) and images at 5 min and 7 min (delayed phase) were obtained serially. Hepatomas showed total enhancement in 18 of 20 patients in the early phase, and isointense or low intensity enhancement with respect to the surrounding liver parenchyma in 18 patients in the late to delayed phases. Hemangiomas showed peripheral enhancement in 14 patients in the early phase, but did not show total enhancement (except for two hemangiomas less than 3 cm in size) in the early phase, and showed high intensity enhancement in 15 patients in the late phase. Ninety percent of hepatomas and 82% of hemangiomas showed their characteristic enhancement patterns in the early to delayed phases. We conclude that dynamic sequential IR snapshot FLASH MR images enhanced with Gd-DTPA can facilitate differentiation between hepatomas and hemangiomas.

Aged↗

PubMedDate not supplied

CT and MR appearances of parotid pseudotumors in Sjögren syndrome.

The radiologic findings in eight patients with parotid pseudotumors associated with Sjögren syndrome (CT in eight; MRI in two) were retrospectively analyzed and compared with the findings in three cases with malignant lymphomas. Diagnosis of pseudotumor was obtained by surgery in six cases and by fine-needle aspiration biopsy and radiologic follow-up in the remaining cases. Six cases (75%) had advanced disease and the remaining had early disease. Both solid (75%) and cystic (38%) masses were seen in the patients with pseudotumors. The masses were solitary in 25%, multiple in 75%, unilateral in 25%, and bilateral in 75%. All three lymphomas were solid masses. The lymphomatous masses were not reliably distinguished from the solid pseudotumors.

Adult↗

PubMedDate not supplied

CT and MRI of siderotic regenerating nodules in hepatic cirrhosis.

The demonstration by CT of siderotic regenerating liver nodules in cirrhosis was evaluated and compared with that of MR imaging retrospectively in 27 patients with histologically diagnosed hepatic cirrhosis. Only in one of the two patients with marked iron deposits in regenerating nodules did CT demonstrate multiple high density nodules. In the other patient with marked iron deposits and in seven of the nine patients with moderate iron deposits, the liver parenchyma on CT was demonstrated as heterogeneous and of slightly high density without focal nodules. In 8 patients with mild to moderate iron deposits and in the 10 with no iron deposits, the liver parenchyma was homogeneous on CT. Multiple low intensity nodules in the liver were seen on fast low-angle shot (FLASH) MR images in all 17 patients with iron deposits in regenerating nodules. No low intensity nodules were seen on FLASH MR images in the 10 patients with no iron deposits. If there are iron deposits above a certain level, siderotic regenerating nodules may appear as nodules of high density on CT or as heterogeneous regions of high density liver parenchyma. Magnetic resonance is more sensitive than CT in demonstrating siderotic regenerating nodules.

Adult↗

PubMedDate not supplied

CT findings in "pseudoalveolar" sarcoidosis.

To determine the specific high resolution CT (HRCT) features for "pseudoalveolar" sarcoidosis, we reviewed HRCT of 10 patients with pathologically proven sarcoidosis. On HRCT the lesions of pseudoalveolar sarcoidosis were shown as homogeneous or inhomogeneous opacities 1-4 cm in diameter located either along the bronchovascular bundles or in the lung periphery adjacent to the pleural surface. The margin was irregular, and numerous nodules 1-2 mm in diameter were observed in the surrounding lung. Air bronchograms were observed in 6 patients. In addition to these lesions, other CT abnormalities such as nodules, groundglass opacities, thickened bronchovascular bundles, and interlobular septa were found in all 10 cases. Good response of pseudoalveolar sarcoid lesions to administration of corticosteroid was observed in all three cases in which follow-up CT was available.

Adult↗

PubMedDate not supplied

3DFT-FISP MRI with gadopentetate dimeglumine in differential diagnosis of small liver tumors.

OBJECTIVE: We assessed the value of dynamic sequential three-dimensional Fourier transformation (3DFT) MRI in differentiating various types of small liver tumors. MATERIALS AND METHODS: Forty-seven patients with 65 liver masses < 3 cm in size (42 hepatocellular carcinomas, 11 hemangiomas, 12 metastatic tumors) were studied by 3DFT fast imaging with steady-state precession (FISP) MRI [TR(ms)/TE(ms)/flip angle (degree): 20/8/30]. The slab thickness was 21-35 mm, and there were seven partitions. The 3DFT-FISP MR images were obtained immediately after 0.1 mmol/kg of gadopentetate dimeglumine was administered intravenously over 2-3 s (early phase), 60 s after (late phase I), and 120 s after (late phase II). RESULTS: Eighty-six percent of small hepatocellular carcinomas showed hyperintense enhancement relative to the surrounding liver parenchyma and iso- or hypointense enhancement with or without capsular enhancement in the late phase. Eighty-two percent of small hemangiomas showed peripheral globular enhancement in the early phase and total hyperintense or peripheral enhancement in the late phases. Ninety-two percent of the small metastatic liver tumors showed doughnut-like ring enhancement in the early phase. CONCLUSION: By dynamic 3DFT-FISP MRI, we were able to accurately evaluate the hemodynamics and morphological findings of each type of small liver tumor.

Aged↗

PubMedDate not supplied

Acute respiratory distress syndrome and acute interstitial pneumonia: comparison of thin-section CT findings.

PURPOSE: The purpose of this work was to compare the thin-section CT findings of acute respiratory distress syndrome (ARDS) with those of acute interstitial pneumonia (AIP). METHOD: The thin-section CT scans from 25 patients with ARDS and 25 with AIP were independently assessed by two observers without knowledge of clinical and pathologic data. The presence, extent, and distribution of various CT findings were independently analyzed. RESULTS: Honeycombing was seen more frequently in lobes of patients with AIP (26%) than in lobes with ARDS (8%) (p < 0.001). Compared with patients with ARDS, a greater number of patients with AIP had a predominantly lower lung zone distribution (p < 0.05) and a symmetric distribution (p < 0.05) of the parenchymal abnormalities. CONCLUSION: Patients with AIP have a greater prevalence of honeycombing and are more likely to have a symmetric bilateral distribution and a lower lung zone predominance than patients with ARDS. However, significant overlap exists among the CT findings.

Acute Disease↗

PubMedDate not supplied

Invasive and noninvasive thymoma: distinctive CT features.

PURPOSE: The purpose of this work was to evaluate the CT features of thymoma and to determine the most helpful findings in differentiating invasive from noninvasive thymoma. METHOD: The CT scans from 27 patients with invasive thymoma and 23 with noninvasive thymoma were independently assessed by two observers without knowledge of their invasiveness. The presence and distribution of various CT findings were independently analyzed. RESULTS: Invasive thymomas were more likely to have lobulated (16/27, 59%) or irregular (6/27, 22%) contours than noninvasive thymomas (8/23, 35% and 1.5/23, 6%, respectively) (p < 0.05). Invasive thymomas had a higher prevalence of low attenuation areas within the tumor (16/27, 60%) than noninvasive thymomas (5/23, 22%) (p < 0.001) as well as foci of calcification (14.5/27, 54% vs. 6/23, 26%; p < 0.01). CONCLUSION: The presence of lobulated or irregular contour, areas of low attenuation, and multifocal calcification is suggestive of invasive thymoma.

Adult↗