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Biomedical subjects

K N Ryu

Publications and source records attributed to K N Ryu.

30 records · Page 2Linked to original sources
PubMed1996

MR imaging of lipoma arborescens of the knee joint.

OBJECTIVE: The purpose of this study was to define MR imaging of patients with lipoma arborescens of the knee. CONCLUSION: MR images showed villous lipomatous proliferation (100%) with signal intensity similar to that of fat on T1- and T2-weighted images, masslike subsynovial fat deposition (38%), joint effusion (100%), erosive bone changes at articular margins (38%), associated synovial cysts (25%), and degenerative changes (13%). MR imaging is a valuable technique for examining patients with lipoma arborescens of the knee and can support the diagnosis of this rare condition.

Adipose Tissue↗
PubMed1995

A small cell osteosarcoma on the calcaneus--a case report.

Small cell osteosarcoma is rare, representing 1-4% of all osteosarcomas. We experienced a case of small cell osteosarcoma in an 8-year-old girl on her calcaneus. Histologically, the tumor consists of small round cells that resemble those of Ewing's sarcoma, and variable foci of lacy osteoid formation between tumor cells. The rare location, histologic characteristics and differential diagnostic points are discussed.

Bone Neoplasms↗
PubMed1993

Adhesive capsulitis of the shoulder joint: usefulness of dynamic sonography.

We studied the value of dynamic sonography in adhesive capsulitis of the shoulder joint in patients with clinically suspected frozen shoulder. The sonographic criterion of adhesive capsulitis was continuous limitation of the sliding movement of the supraspinatus tendon against the acromion of the scapula. Arthrography was regarded as a gold standard in the diagnosis of adhesive capsulitis against which the sonographic results were compared. Among 23 patients with arthrographically documented adhesive capsulitis, sonographic examination showed limitation of movement of the supraspinatus tendon in 21. This sonographic sign therefore has a sensitivity of 91%, a specificity of 100%, and an accuracy of 92% for detecting adhesive capsulitis, making dynamic sonography a reliable technique for the diagnosis of this condition.

Adult↗
PubMed1991

Giant cell tumor of the scapula associated with secondary aneurysmal bone cyst.

Giant cell tumors are distinctive neoplasms characterized by a profusion of multinucleate giant cells scattered throughout a stroma of mononuclear cells. Most giant cell tumors are found at the epiphyses of long bones, especially around the knee joint. Flat bone involvement is rare. However, a case of giant cell tumor with secondary aneurysmal bone cyst was encountered at the scapula of a 25-year-old man. Since the occurrence of a giant cell tumor with secondary aneurysmal bone cyst on flat bones (i.e., the scapula) is extremely rare, the above-mentioned case is worthy of reporting.

Adult↗
PubMed1990

Medial extent of the posterior renal fascia. An anatomic and computed tomography study.

To study the medial extent of the posterior renal fascia and the perirenal space, the authors dissected two cadavers and reviewed 50 computed tomographic (CT) abdominal scans. The results demonstrated that the medial extent of the posterior renal fascia depends on the level in a vertical direction and its relationship to the kidney which varies at different levels. At the renal hilus, the fascia inserts posteromedially to the fascia of the quadratus lumborum along its lateral margin; more cranially, the line of insertion is more lateral, onto the diaphragmatic fascia; more caudally, the line of insertion is more medial, inserting onto the anterior surface of the quadratus lumborum. Therefore the posteromedial insertion of the posterior renal fascia extends medially, from the more laterally placed diaphragmatic fascia, to the lateral margin of the quadratus lumborum and then to the anterior surface of the quadratus lumborum, depending on the anatomic level. The clinical implication of these findings are discussed.

Cadaver↗
PubMed1990

Anatomic relationship of intrahepatic bile ducts to portal veins.

To assess the anatomic relationship between the intrahepatic bile ducts and corresponding portal veins, we studied anterior-posterior relationship of the segmental bile ducts to the accompanying portal veins using sonograms and cadavers. On sonograms of the 64 segments in 16 patients with biliary dilation, the segmental bile ducts lay anterior to the corresponding portal veins in 34%, posterior in 39%, superior in 2%, tortuous in 13%, and undetermined in 13%. The relationship was inconsistent in terms of hepatic segments and thus bile ducts lay anterior to the portal vein in one segment and posterior in the other segment within the same liver. Sagittal sections in 11 segments of the 3 cadaveric livers revealed that the bile ducts were anterior to the corresponding portal veins in 1 segment, posterior in 2 segments, superior in 5 segments, anterosuperior in 1 segment, and posterosuperior in 2 segments. It is concluded that, contrary to the common belief, there is no constant anterior-posterior relationship between the intrahepatic bile ducts and the corresponding portal veins.

Bile Duct Diseases↗
PubMed1988

Superior aspect of the perirenal space: anatomy and pathological correlation.

To study the anatomy of the superior aspect of the perirenal space, we analysed 50 computed tomographic (CT) scans with reference to the anatomy of Gerota's fascia, and dissected five cadavers laying special emphasis on the ascent of Gerota's fascia. We also reviewed 10 scans of patients with a large lesion in the right upper abdomen regarding localisation of the lesion. We conclude that Gerota's fascia does not cover the upper portion of the kidney and adrenal gland so that the superior aspect of the perirenal space is open towards the upper abdominal extraperitoneal space. Thus, a large lesion arising from the right adrenal gland or kidney easily invaginates the liver through the bare area mimicking a hepatic lesion, and vice versa. This explains the difficulty in localising a large lesion in the right upper abdomen.

Humans↗
PubMedDate not supplied

Bone bruises: MR characteristics and histological correlation in the young pig.

PURPOSE: To correlate magnetic resonance (MR) signal characteristics of bone bruises with histological findings. MATERIALS AND METHODS: In 14 tibiae of young pigs, bone bruises were created in the proximal tibial metaphysis. The signal intensity seen on the MR images were correlated with histological findings. The following findings were evaluated: (a) changes of signal intensity on the tibiae; (b) changes of histology on the tibiae; and (c) changes of (a) and (b) on follow-up examinations. RESULTS: We observed three types of injuries on T1-weighted images: focal or diffuse low signal, normal signal and linear low signal intensities. Severe hemorrhagic areas showed low signal intensities on all sequences of MR imaging. Fast spin-echo (FSE) T2-weighted images showed a more distinct low signal intensity than T1-weighted images. FSE short tau inversion recovery (STIR) and FSE fat saturated (FSE-FS) T2-weighted images showed similar signal intensities with FSE T2-weighted images. FS T1-weighted enhanced images showed low signal intensities with variable enhancements. Upon histological examination, hemorrhages and edemas were prominent at the subcortical areas of the contusion sites. The areas of dense, low signal intensities in all imaging sequences showed signs of severe hemorrhage. The areas of diffuse low signal and enhanced areas showed mixed areas of hemorrhages and edemas. Follow-up MR imaging showed evolution of the processes of hemorrhages and edemas with fatty marrow changes. CONCLUSIONS: MR imaging can depict changes in the bone marrow resulting from direct injury to the bone. MR imaging is a useful tool for evaluating the evolution of bone bruises.

Animals↗
PubMedDate not supplied

Osteonecrosis in patients with systemic lupus erythematosus: MR imaging and scintigraphic evaluation.

This study was to describe the findings of osteonecrosis in patients with SLE at MR and scintigraphic imaging. Among 415 patients with SLE, 37 patients were diagnosed to have osteonecrosis. MR images and bone scintigraphs were analyzed for sites of involvement, signal intensity, bilaterality and multiplicity. MR imaging features of osteonecrosis in patients with SLE included isointense signal intensity relative to adjacent bone marrow, hypointense rim, marginal enhancement and unusual involvement of flat bones. Bilateral and multiple involvements were common.

Adolescent↗
PubMedDate not supplied

Spinal involvement of hematopoietic malignancies and metastasis: differentiation using MR imaging.

The purpose of this study was to determine the usefulness of magnetic resonance imaging (MRI) for distinguishing spinal involvement of hematopoietic malignancies (lymphoma, leukemia, and multiple myeloma) from metastasis. 62 spinal MRIs were obtained in 60 patients with hematopoietic malignancies (n = 24) and metastasis (n = 36) in clinically and pathologically proven cases. MRI findings were evaluated in each group of patients for the pattern of involvement, signal change of vertebral body, location of paraspinal mass formation, location of epidural mass formation, cortical destruction, contour change, and compression fracture. Diffuse involvements were more commonly seen in hematopoietic malignancies than in metastasis (p < 0.05). Signal change confined to anterior element was seen in 9 metastasis but was not seen in hematopoietic malignancies. Cortical destructions were more commonly seen in metastasis than in hematopoietic malignancies (p < 0.05). Other findings did not show any statistical significance in both groups. MRI findings such as diffuse involvement, posterior epidural mass formation, and cortical destruction were useful to distinguish spinal involvement of hematopoietic malignancies and metastasis.

Adolescent↗
PubMedDate not supplied

Chondroblastoma: MR characteristics with pathologic correlation.

PURPOSE: The purpose of this study was to describe the MR findings of chondroblastoma with pathologic correlation. METHOD: In 22 patients with pathologically proven chondroblastoma, MR signal characteristics were correlated with pathological findings. RESULTS: On T2-weighted images, 12 (55%) lesions were hyperintense with hypointense areas in 9 lesions, whereas 10 (45%) were hypointense. Therefore, 19 of 22 (86%) lesions with pathologic correlation had hypointense areas entirely (n = 10) or partly (n = 9) on T2-weighted images. On gadolinium-enhanced images, 13 (59%) lesions showed lobular enhancement and 9 (41%) showed marginal and septal enhancement. Low signal intensity on T2-weighted MR images was most strongly associated with an abundance of immature chondroid matrix, hypercellularity of the chondroblasts, calcifications, and hemosiderin on histology. CONCLUSION: Chondroblastoma was found to show hypointense portions on T2-weighted images. Signal intensity on T1- and T2-weighted MR images in chondroblastoma was dependent on the amounts of histopathological components.

Adolescent↗