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Biomedical subjects

M Uetani

Publications and source records attributed to M Uetani.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Efficacy of respiratory-triggered fast spin-echo 3 dimensional-MR cholangiopancreatography on middle magnetic field MR imaging].

We compared the image quality of three-dimensional (3D) MR cholangiopancreatography (MRCP) and two-dimensional (2D) MRCP on middle magnetic field MR imaging, using a respiratory-triggered fast spin-echo technique in 10 volunteers and 69 patients suspected of having biliary and pancreatic diseases. The bile ducts (BDs) and main pancreatic ducts (MPDs) are, if dilatated, are almost always depicted by 3D-MRCP and 2D-MRCP. The depiction rates by 3D-MRCP of non-dilatated intrahepatic ducts (IHDs), hepatic ducts (HDs), common hepatic ducts, common BDs, cystic ducts (CDs) and MPDs were 57%, 90%, 95%, 95%, 100% and 77%, respectively. The respective rates for 2D-MRCP were 26%, 95%, 100%, 95%, 74% and 38%. Non-dilatated IHDs, CDs, and MPDs were better visualized on 3D-MRCP than on 2D-MRCP, because of the high contrast to-noise ratio and high spatial resolution in the slice-section direction of 3D-MRCP. In conclusion, respiratory triggered fast spin-echo 3D-MRCP on middle magnetic field MR imaging is useful in the evaluation of biliary and pancreatic diseases.

Adult↗
PubMed1996

Renal cell carcinoma in a patient with Beckwith-Wiedemann syndrome.

We report the case of a patient with Beckwith-Wiedemann syndrome (BWS) who developed renal cell carcinoma (RCC). At birth, this patient presented with macroglossia, diastasis recti, mild gigantism, hepatomegaly and hypoglycemia, and the diagnosis of BWS was made. At 22 months, an intrapelvic rhabdomyosarcoma was detected and resected. At 37 months, computed tomography (CT) demonstrated a small mass with high attenuation in the right kidney, which was surgically confirmed to be RCC.

Beckwith-Wiedemann Syndrome↗
PubMed1996

Tuberculous tenosynovitis of the wrist: MRI findings in three patients.

We report recent MRI findings in patients with tuberculous tenosynovitis of the wrist. Marked synovial thickening around the flexor tendons and fluid in the tendon sheath were clearly shown on MRI. Post-contrast study was useful in distinguishing the thick tenosynovium from the surrounding structures and fluid in the tendon sheath. The well-enhanced tenosynovium was also seen in the carpal tunnel in all cases. On the basis of these findings, we could easily distinguish tenosynovitis from other soft-tissue-mass lesions, such as tumors or infected ganglia. Tuberculous tenosynovitis is often not diagnosed early, and its differentiation from soft tissue tumors may be clinically difficult. MRI, particularly post-contrast study, is useful for early diagnosis of, and planning treatment for, tuberculous tenosynovitis.

Humans↗
PubMed1996

Gadolinium-enhanced MR imaging of the wrist in rheumatoid arthritis: value of fat suppression pulse sequences.

OBJECTIVE: To determine the usefulness of fat-suppressed gadolinium (Gd)-enhanced MR imaging of the wrist in patients with rheumatoid arthritis (RA). DESIGN AND PATIENTS: Fat-suppressed Gd-enhanced T1-weighted spin-echo (SE) images were obtained and compared with other standard techniques in 38 wrists of 27 patients (22-77 years) with RA. Scoring based on the degree of synovial enhancement of each joint was developed and the total scores (J-score) were correlated with radiographic stage, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and symptomatic change in the follow-up study. RESULTS: Synovial proliferations showed marked enhancement in all the wrists. In addition, contrast enhancement in the bone marrow and tenosynovium was seen in 36 and eight wrists respectively. Fat-suppressed Gd-enhanced T1-weighted images demonstrated these abnormalities better than other techniques. The J-scores correlated well with values of CRP (P = 0.0034), but not with radiographic stages and ESR. CONCLUSION: Fat-suppressed Gd-enhanced T1-weighted SE images can clearly demonstrate most of the essential lesions in RA including the proliferative synovium, bone erosion, bone marrow inflammatory change, and tenosynovitis. Scoring based on the extent of Gd-enhancement of synovium can be useful in the assessment of the inflammatory status.

Adult↗
PubMed1996

MR imaging of the lacrimal gland. Age-related and gender-dependent changes in size and structure.

PURPOSE: The subject of this study was to define age-related and gender-dependent changes in MR features of the lacrimal gland. MATERIAL AND METHODS: MR images were retrospectively analyzed in 104 normal subjects aged 2-79 years to measure thickness and area of the lacrimal gland, its MR signal intensity ratio, and SD of the MR signal intensity profile. RESULTS: Thickness and area of the lacrimal gland decreased with age in women (p < 0.001), but not in men. Furthermore, MR signal intensity ratio of the lacrimal gland showed an age-related increase in women (p < 0.001), but not in men. On the other hand, SD of the MR signal intensity increased with age in both women and men (p < 0.001). CONCLUSION: These findings demonstrate that gender has a significant influence on lacrimal gland structure during development and aging.

Adolescent↗
PubMed1996

MR imaging of the parotid gland in Sjögren's syndrome: a proposal for new diagnostic criteria.

OBJECTIVE: Because classic diagnostic techniques for sjögren's syndrome (SS) are invasive and require radiation exposure, a noninvasive diagnostic method might benefit patients with SS. The purpose of this study was to determine whether quantitative analysis of MR images of the parotid gland can differentiate patients with SS from normal subjects. SUBJECTS AND METHODS: We performed quantitative analysis of MR images of the parotid gland for 40 patients with definite and probable SS, for 30 normal subjects matched by age and sex to the SS patients, and for 10 patients with parotid inflammation. MR images of teh parotid gland were assessed by calculating standard deviations (SD) of signal intensity. RESULTS: SD of signal intensity exclusively (p < .0001) separated MR images of the parotid glands of patients with definite SS from those of normal subjects. SD of signal intensity for the parotid glands of patients with probable SS also were significantly higher (p < .001) than those of normal subjects. Changes in signal intensity were specific for SS and did not occur with parotid inflammation. Tentative categorization on the basis of signal intensity patterns on MR images of the parotid glands of SS patients showed a high correlation with the results of labial gland biopsy (r = .834) and sialography (r = .936). CONCLUSION: Taken together, these results conclusively indicate that quantitative analysis of MR images for SD of signal intensity is useful method for diagnosing SS and can replace classic methods, which are invasive.

Adolescent↗
PubMed1995

Relation of early menarche to high bone mineral density.

The study of background factors in individuals with high bone mineral density (BMD) may provide useful information in the prevention of osteoporosis. We investigated the relationship of reproductive factors to BMD. In 519 female volunteers (327 postmenopausal and 192 premenopausal women) ranging in age from 21 to 74 (mean 52.3 +/- 11.8) years, spinal BMD values were obtained using both quantitative computed tomography and dual x-ray absorptiometry. The z score was calculated from the mean BMD in each 5-year age group, and high BMD and low BMD was defined as BMD with z score > + 1.5 and < -1.5, respectively. Normal BMD was defined as BMD within the range - 1.0 < z score < +1.0. Long reproductive period, early menarche, and late menopause were associated with high BMD. Among these, the reproductive period showed the strongest association with BMD. In postmenopausal women, early menopause had a significant relationship with low BMD, and early menarche also had some relation to high BMD. In premenopausal women, there was a significant relationship between early menarche and high BMD. The age at menarche may have a strong association with peak bone mass, as suggested by the positive correlation of early menarche with high BMD observed in this study. It is considered important to prevent risk factors that disturb the beginning of menstruation in adolescent girls.

Absorptiometry, Photon↗
PubMed1995

Trabecular texture analysis of CT images in the relationship with spinal fracture.

PURPOSE: To evaluate age-related changes in trabecular texture and bone mineral density (BMD) and to determine the usefulness of texture analysis in the assessment of the risk of fracture. MATERIALS AND METHODS: The vertebral trabecular BMD was measured in 209 women aged 18-86 years. Run length analysis was applied to computed tomographic images obtained with 2-mm section thickness. The width of the trabecula (T-texture) and the width of the intertrabecular space (I-texture) were calculated. RESULTS: I-texture significantly increased with age in women 50 years of age or older (P < .0001). Women with fracture had significantly lower BMD (P < .0001 at 60-69 years, P < .05 at 70-79 years) and significantly higher I-texture (P < .05 at 60-69 years, P < .01 at 70-79 years). For fracture risk, BMD had the highest sensitivity and I-texture had the highest specificity in women aged 60-69 years; I-texture had the highest sensitivity and specificity in women aged 70-79 years. CONCLUSION: Texture analysis was helpful in the assessment of fracture risk, especially in elderly women.

Adolescent↗
PubMed1995

Untreated Graves' disease patients without clinical ophthalmopathy demonstrate a high frequency of extraocular muscle (EOM) enlargement by magnetic resonance.

12 of 17, a significant frequency (71%), of untreated Graves' disease patients with no clinical ophthalmopathy showed extraocular muscle (EOM) enlargement by Magnetic Resonance Imaging (MRI). Enlargement was bilateral in 41% and unilateral in 29% in these patients. Apparent enlargements of EOM were also detected, by MRI, in all of 11 Graves' disease patients with clinical ophthalmopathy, bilateral in 73% and unilateral in 27% of patients in this group. Both group showed the inferior rectus muscle as the most frequently involved (56% and 77% respectively). In 16 patients without autoimmune thyroid disorders or ophthalmopathy who served as normal controls, only 2 of these patients (12%) demonstrated mild EOM enlargement. The severity and patterns of EOM enlargement revealed no correlation with abnormalities in serum thyroid function tests or serum thyroidal autoantibodies. In conclusion, a high frequency of Graves' disease patients without clinical eye signs or symptoms harbor EOM abnormalities, as demonstrated by MRI. This suggests that present clinical examination methods are insufficient to diagnose varying degrees of ophthalmopathy in patients with autoimmune thyroid disorders who do not initially present with clinical ophthalmopathy.

Adolescent↗
PubMed1995

Synovial chondromatosis of the temporomandibular joint.

A case of synovial chondromatosis of the temporomandibular joint in a 48-year-old woman is presented. Computed tomography and magnetic resonance imaging contributed to a clear understanding of the extent of the lesion and were helpful in both surgical treatment planning and follow-up.

Chondromatosis, Synovial↗
PubMed1995

Normal age-related conversion of bone marrow in the mandible: MR imaging findings.

OBJECTIVE: The mandible is one of the most common sites for osteomyelitis and other marrow-based diseases. Therefore, knowledge of the normal patterns of marrow distribution could help evaluate marrow-based diseases. The purpose of this study was to assess the age-related normal sequence of conversion from hematopoietic to fatty marrow in the mandible as depicted on MR images. SUBJECTS AND METHODS: We prospectively reviewed T1-weighted MR images of the mandible for the distribution of hematopoietic and fatty marrow. Forty-five subjects 4 months to 25 years old with no known marrow abnormality were examined with the spin-echo technique. Marrow conversion was assessed in the condyle, ramus, angle, and body of the mandible using visual grading based on homogeneity, signal intensity, and a signal-intensity ratio determined by the intensities of the surrounding subcutaneous fat and air. RESULTS: Conversion of hematopoietic to fatty marrow occurred first in the mandibular body, followed by the angle, ramus, and finally the condyle. The marrow in the region distal to the ramus had almost fully converted to fatty marrow by the third decade of life, but the remaining regions contained some hematopoietic marrow. Further substantiating these results, the signal-intensity ratio increased up to about 90% in the angle and 70% in the ramus by the age of 10 years and then leveled off. On the other hand, the signal-intensity ratio in the condyle reached 60% by age 15 and remained unchanged for the following 10 years. CONCLUSION: The normal age-related conversion from hematopoietic to fatty marrow in the mandible follows a well-defined sequence, first seen in the mental region early in childhood, then in the body, the ramus, and finally the condyle.

Adolescent↗
PubMed1995

[Magnetic resonance imaging of sacral insufficiency fractures: characteristic features and differentiation from sacral metastasis].

Seven patients with sacral insufficiency fractures and seven patients with sacral metastasis were studied with MR imaging. The diagnoses were confirmed with other imaging modalities and clinical follow-up. The insufficiency fractures appeared as bands of abnormal signal: low signal intensity on T1-weighted images and slightly low to iso signal intensity on T2-weighted images. The lesions were delineated better on T1-weighted images than on T2-weighted images. The sacral alae were involved in all patients; five patients had bilateral lesions. The lesions that run across the sacral body were seen in three cases. Inclined coronal images were useful in demonstrating the pattern of distribution of the sacral insufficiency fractures. In three patients with follow-up MR studies, the lesions were markedly reduced or disappeared. The sacral metastatic tumors were of low signal in density on T1-weighted images and iso to high signal in density on T2-weighted images. The extent and distribution patterns of the lesions were various. It is possible to differentiate sacral insufficiency fractures from sacral metastases based on their distribution patterns on MRI. However, if the diagnosis is uncertain or if the symptoms persist or become worse, follow-up MR studies may be necessary.

Aged↗
PubMed1994

Association between anthropometric measures and spinal bone mineral density.

RATIONALE AND OBJECTIVES: The relationship of vertebral bone mineral density (BMD) to various anthropometric factors, including body weight and height, vertebral volume, and muscle area was examined. The sex- and menopause-related differences in these relationships also were studied. METHODS: Both cortical and trabecular BMD were measured using quantitative computed tomography (QCT). Integral BMD was measured using dual x-ray absorptiometry (DXA) in 74 men and in 96 premenopausal and 155 postmenopausal women. The psoas muscle area was measured using CT images. Vertebral volume was determined using CT images and CT topography. RESULTS: Bone mineral density had the strongest relationship with age in postmenopausal women. Trabecular BMD was correlated with muscle area and vertebral volume in premenopausal women, but not in postmenopausal women. The correlation of trabecular BMD with various anthropometric factors in men was stronger than that in women. Dual x-ray absorptiometry-BMD was found to be more affected by bone volume than was QCT-BMD. CONCLUSIONS: The association of anthropometric factors with BMD differs in men and women, as well as in premenopausal and postmenopausal women.

Absorptiometry, Photon↗
PubMed1994

Aortic dissection caused by angiographic procedures.

PURPOSE: To describe findings in, and the clinical course and outcome of, aortic dissection (dissecting aneurysm) caused by angiographic procedures. MATERIALS AND METHODS: The records of approximately 15,500 angiographic procedures performed between 1985 and 1991 were reviewed. In the six cases of iatrogenic aortic dissection identified, computed tomography (CT) was performed for diagnosis, follow-up, or both. RESULTS: The type of aortic dissection was Stanford type A in three patients and Stanford type B in three patients. The sites of injury were the abdominal aorta (n = 2), right brachiocephalic artery (n = 2), middle of the thoracic aorta (n = 1), and right common iliac artery (n = 1). One patient had anterograde dissection from the site of injury; two patients, retrograde dissection; and three patients, extensive dissection that extended in both anterograde and retrograde directions. Retrograde dissections decreased in size or disappeared in 1-3 months due to the absence of reentry, whereas anterograde dissections persisted during follow-up (15-27 months). All patient were treated without surgery. CONCLUSION: Angiographers should be aware of this potentially serious complication. The extent and type of the aortic dissection can be determined with CT.

Aged↗
PubMed1994

Case report: the "aurora sign"--a new sonographic sign of pneumatosis cystoides intestinalis.

Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by multiple gas-filled cysts of varying size within the intestinal wall. Although the characteristic findings on plain abdominal radiograph, computed tomography (CT), and barium enema have been well described, the sonographic findings have not. We recently encountered a case of PCI in which abdominal sonography disclosed a unique finding. We were able to reproduce the finding experimentally and have coined it the "aurora sign".

Humans↗
PubMed1993

[Rounded atelectasis with emphasis on its wide spectrum].

While rounded atelectasis (RA) is considered to be rather common in the United States and Europe, the total number of RA cases reported from Japan still remains approximately 30. We have long been aware that there are many variations in the radiographic appearance of so-called RA and that RA has never been clearly defined. We retrospectively reviewed 22 cases collected as RA and its variants from several institutions. We defined RA as "peripheral atelectasis mimicking tumor secondary to shrinkage or bending of the pleura of various degrees, and accompanied by lung distortion." The diagnostic criteria of typical RA include (1) peripheral tumoral shadow in contact with pleural effusion or thickened pleura, (2) acute angle between the pleura and the shadow, (3) convergence of the pulmonary vessels and bronchi and (4) volume loss of the affected lobe. However, there are cases which lack some of these criteria but are considered to be included in the broad category of RA. We propose that RA should be considered to be an entity having a wide spectrum. Typical lesions showing "cranial tilting" of Hanke are on one side of the spectrum and small linear or strand shadows extending from the thickened pleura are on the other.

Adult↗
PubMed1993

[CT findings of invaginated mesentery in adult intussusception].

The CT findings of invaginated mesentery in adult intussusception were analyzed in 12 patients (three patients with four small bowel intussusceptions and nine patients with nine large bowel intussusceptions). In all small bowel intussusceptions, the neck was located near the superior mesenteric artery and vein (SMA & SMV) and showed a medial opening, and the vessels in the neck showed a continuity to the left side of SMA & SMV. In most of the large bowel intussusceptions, the neck was located distant from SMA & SMV, and the vessels in the neck did not show continuity to SMA & SMV. The difference in CT findings between small and large bowel intussusception is attributed to the difference in mesenteric anatomy; the small bowel and its mesentery move freely in the peritoneal cavity, whereas the large bowel is partially fixed to the retroperitoneum.

Adult↗