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Biomedical subjects

S Ehara

Publications and source records attributed to S Ehara.

At least 73 records · Page 4Linked to original sources
PubMed1994

Case report 859: Massive calcium pyrophosphate dihydrate crystal deposition disease involving the wrist joint.

A case of massive calcium pyrophosphate dihydrate crystal deposition disease (MCPDD) is reported. A 41-year-old Japanese man presented with swelling, intermittent pain, and limitation of motion in the wrist. Radiological studies indicated amorphous calcification and bone erosion. MCPDD, although rare, should be included in the list of the differential diagnosis of periarticular calcific diseases.

Adult↗
PubMed1994

Magnetic resonance imaging of pseudomalignant osseous tumor of the hand.

Noninfectious, nonneoplastic reactive processes of the hand, such as myositis ossificans circumscripta, pseudomalignant osseous tumor of soft tissue, and florid reactive periostitis, appear similar radiologically and histologically and are often difficult to differentiate. Magnetic resonance (MR) findings in two such lesions are reported. The extensive reactive change in the extraosseous soft tissue and the bone marrow and the relatively small extent of ossification may be characteristic. Although low-grade infection and small osseous neoplasms with reactive changes, such as osteoid osteoma, may still remain possible causes, MR imaging provides essential evidence for including noninfective, nonneoplastic reactive processes of uncertain cause in the list of differential diagnoses.

Adult↗
PubMed1994

Fluid-fluid levels in cavernous hemangioma of soft tissue.

Five cases of cavernous hemangioma with fluid-fluid levels on magnetic resonance imaging and/or computed tomography are reported. The signal characteristics were those of blood and histological analysis of the fluid-fluid levels showed that they were blood-filled cavities in the tumor. Although this finding itself is not specific, it may help in confirming the diagnosis of cavernous hemangioma.

Biomarkers↗
PubMed1994

Case report 829: Intramuscular myxoid chondrosarcoma.

A 61-year-old man presented with a 6-month history of a painless mass in the right buttock. Although the MR appearance of myxoid neoplasms is variable, a myxoid neoplasm was suspected on the basis of the MR study. Percutaneous needle biopsy results yielded a diagnosis of intramuscular myxoma. Myxoid chondrosarcoma, however, was diagnosed at the time of excisional biopsy. One should be wary of a diagnosis of intramuscular myxoma based solely on the results of percutaneous needle biopsy. In addition, myxoid chondrosarcoma of the soft tissues can have a variable appearance on T1-weighted imaging.

Buttocks↗
PubMed1993

Hippocampal sulcus remnant: potential cause of change in signal intensity in the hippocampus.

A small area of changed signal intensity in the hippocampus is often seen on magnetic resonance (MR) images of the brain in patients without specific clinical signs or symptoms. To ascertain its cause by means of histologic examination, this finding was evaluated retrospectively in 109 patients and correlated with findings in two human brain specimens. This area of change was typically round or curvilinear and 1-2 mm in diameter. Its location was between the hippocampus and dentate gyrus. The signal intensity was the same as that of cerebrospinal fluid (CSF) with all MR sequences used. The incidence of change in signal intensity was greater in elderly patients. Correlation with histologic findings showed that this area of change, a dilated perivascular space, was the residual cavity of the hippocampal sulcus. Whenever an area of CSF-like signal intensity has this shape and topographic features, the possibility of anatomic variation should be considered before the change in signal intensity is diagnosed as brain injury.

Adolescent↗
PubMed1993

Vesicourethral function after surgery for uterine cancer: predictive value of postoperative maximum urethral closure pressure on residual urine.

Using a urodynamic technique, vesicourethral function was evaluated in 30 patients who had undergone surgery for uterine cancer. In all 28 patients treated with radical hysterectomy, detrusor function was damaged irrespective of the use of the Cavitron ultrasonic surgical aspirator (CUSA), whereas, in 2 patients treated with semiradical hysterectomy, the function was preserved. Vesicourethral functions 3 weeks after the operation in all 28 patients treated with radical hysterectomy showed underactive detrusor function with low compliance. In 10 out of these 28 patients, postoperative maximum urethral closure pressure (MUCP) did not decrease, without relation to the use of CUSA nor to the presence of detrusor sphincter dyssynergia, and more than 5 weeks were required to reduce residual urine to less than 50 ml. On the other hand, in the remaining 18 patients, postoperative MUCP decreased, and residual urine decreased to less than 50 ml by 5 weeks after the operation. From the results obtained here, we can conclude that the evaluation of MUCP at an early phase after the operation is a useful tool to predict complications caused by residual urine, such as urinary tract infection, irreversible alteration of detrusor function or deterioration in renal function.

Female↗
PubMed1992

[Pseudodynamic MR imaging of temporomandibular joint disorders].

Magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) has now been established as a procedure of choice in the evaluation of TMJ disorders. In this study, we evaluated the dynamics of TMJ motion on MR imaging, which resembles arthrography. Sixty-eight TMJs in 38 symptomatic patients and one healthy volunteer were examined using pseudodynamic images with gradient echo sequences using a 0.5 Tesla MR unit and 8 cm circular planar surface coil. For depiction of each compartment of the meniscus, the optimum sequence was 200/15/2 (TR/TE/excitations) with 50 degrees or 60 degrees flip angle in gradient refocused acquisition in steady-state (GRASS) sequences. Three contiguous slices on sagittal MR images were routinely obtained at 14-18 different phases of the opening cycle and displayed in closed-loop cine fashion. Internal derangement was observed in 57% of 68 joints. The most common type was anterior meniscal displacement without reduction. Sideway and rotational displacements, observed in 10% each, were noted on both sagittal multislice images and axial reference images. As a pseudodynamic MR technique, jaw movement specifically designed to check bite procedure to adjust splints is useful for detecting the exact time of meniscal redisplacement on the second click. After conservative therapy for arthrosis, pseudodynamic MR provided information on changes in the meniscus and condylar relationship. Pseudodynamic MR with multiple phases is suitable for evaluating subtle motion abnormality of the meniscus and for post-therapeutic monitoring.

Adult↗
PubMed1992

[Fluid-fluid levels in bone and soft tissue tumors demonstrated by MR imaging].

Fluid-fluid levels in bone tumors have been described in aneurysmal bone cysts and other cystic tumors of bones and soft tissue tumors. We experienced three bone tumors (simple bone cyst, bone metastasis, and osteosarcoma) and three soft tissue tumors (fibrosarcoma, two cases of cavernous hemangioma) that showed fluid-fluid levels on MR, and investigated their cause. Causes included blood in the cystic spaces, hemorrhage in the tumor, the telangiectatic component of the osteosarcoma, and the cavernous component of the hemangioma. No specific diagnosis could be made based on the finding of fluid-fluid levels. We conclude that fluid-fluid levels on MR are rather nonspecific findings in bone and soft tissue tumors and that the diagnosis should be made on the basis of other radiological and clinical findings.

Adult↗
PubMed1992

Limited remodelling of expansile Ewing sarcoma after treatment.

Radiological findings of Ewing sarcoma have been well documented, and bone expansion or cystic change is known to be a relatively uncommon finding. On the other hand, expected changes in Ewing sarcoma after treatment have also been reported, e.g. regression of extraosseous soft tissue mass, regression and organization of the periosteal reaction, and remodelling of the lytic or sclerotic bone changes. However, remodelling of bone is often limited or incomplete. We saw an atypical change in Ewing sarcoma after treatment due to lack of significant remodelling of the expanding bone. Because such changes might be a cause of misdiagnosis, knowledge of it will help the radiologist in the follow up evaluation.

Adult↗
PubMed1992

[Simultaneous pseudodynamic MR evaluation of bilateral temporomandibular joints].

Coordination of bilateral temporomandibular joints (TMJs) was evaluated using bilateral simultaneous pseudodynamic magnetic resonance (MR) imaging. Seven patients (6 patients with internal derangement and one with osteoarthritis) were examined by multiplanar gradient echo technique in closed-loop cine fashion on both sagittal and coronal planes. Incoordination of bilateral TMJ motion was observed in 2 of 7 patients. This technique might be suitable for evaluation of TMJ disorders.

Humans↗
PubMed1992

Radiologic evaluation of dens fracture. Role of plain radiography and tomography.

A retrospective study of 50 dens fractures was performed. In 47 of 50 cases (94%), plain radiographs disclosed the fracture. Initial cross-table lateral view alone showed the fracture in 43 cases. In the remaining four cases, routine plain films revealed the fracture: open-mouth view in three cases and lateral skull view in one case. In 3 of 50 cases (6%), plain films were negative, and fractures were seen only on tomography. Conventional circular tomography was performed in 26 cases; results were divided into 3 categories according to the significance of the findings: Category I, tomography confirmed plain radiographic findings, but added no further information; Category II, tomography detected additional findings or showed the extent of injury better than plain radiography; Category III, fracture was only seen by tomography. There were 19 cases in Category I, 4 in Category II, and 3 in Category III. Careful evaluation of plain radiographs remains the primary method for diagnosis of dens fractures. Tomography should be performed whenever plain radiographs or clinical symptoms are suspicious for dens fracture. In addition, tomography is useful to define the fracture level and pattern, which are important factors in the management of these injuries.

Cervical Vertebrae↗
PubMed1991

Ewing's sarcoma. Radiographic pattern of healing and bony complications in patients with long-term survival.

The radiographic appearance of Ewing's sarcoma was studied retrospectively in 22 patients who survived 5 years or longer after diagnosis and treatment. Expected changes from treatment, including regression of the extraosseous soft tissue mass, periostitis, and reconstitution of the cortex, occurred in all patients. Local recurrence occurred in one patient 10 years after complete remission whereas secondary osteosarcoma occurred more than 5 years after complete remission in two other cases. Both recurrent and secondary tumors presented as new lytic foci at the site of the original primary lesion. Lytic changes from radiation (radiation osteitis) may develop more than 2 years after treatment and in this sample; such findings were widely distributed in the radiation port. The authors conclude that bone remodeling and postradiation changes occur slowly over 2 years after treatment, and that any localized lysis at the primary site is suspicious for recurrence or secondary neoplasm. Knowledge of the expected changes and patterns of local recurrence and secondary neoplasms helps one to detect any significant change in its early phase.

Adolescent↗
PubMed1991

[MRI and arthrography in the evaluation of TMJ disorders].

Arthrosis of the temporomandibular joint (TMJ) is a noninfectious, noninflammatory condition characterized by joint pain, noise (clicking) and abnormal motion. It contains various disease processes, such as abnormalities in the menisci or masticating muscles, subluxation of the condyle and degenerative joint disease. Analysis of the morphology and dynamics of TMJ by means of imaging modalities has become highly advanced since the development of arthrography in the late 1970s. Magnetic resonance imaging (MRI) has become the modality of choice in the evaluation of TMJ owing to the development of surface coils. We retrospectively studied MRI and inferior joint compartment arthrography in the evaluation of TMJ disorders. Nineteen joints of 14 patients included 15 with internal derangement, two with osteoarthrosis and two normal joints. Sagittal MR images were routinely obtained in a resting position and in positions with the mouth half open, and also with the mouth fully open on balanced images. Although perforation of the menisci was difficult to evaluate, MRI and arthrography were equally useful in identifying the shape and position of the meniscus. However, MRI was more reliable in depicting TMJ abnormalities than arthrography. MR is considered to be the modality of choice in screening arthrosis of TMJ, making the definitive diagnosis of internal derangement and monitoring conservative therapy for arthrosis.

Adult↗
PubMed1991

Case report 675: Lipoblastoma of knee.

Lipoblastoma in the prepatellar region was observed in a 7-month-old girl. The diffuse (lipoblastomatosis) and circumscribed forms have different radiological appearances. Lobular proliferation of fatty tissue with fibrous septae is characteristic of the circumscribed form.

Female↗
PubMed1991

Malignancy supervening on an intramedullary nail.

A primary, malignant, fibrous histiocytoma of bone occurring in association with a Hansen Street intramedullary nail occurred in a 39-year-old man. The physical and chemical characteristics of materials, in relation to the generation of secondary neoplasia are reviewed, but the problem of coincidence is difficult to exclude.

Adult↗