No abstract available.
Magnetic Resonance Imaging*

Wallerian degeneration is well known as the anterograde degeneration of axon and their accompanying myelin sheath from injury to the proximal portion of the axon or its cell body. The most common cause of wallerian degeneration is cerebral infarction. Authors experienced three patients with old hemispheric infarct with typical wallerian degeneration in the brain stem, which was demonstrated by magnetic resonance imaging (MRI) in two cases and CT in one case. This report demonstrates the wallerian degeneration in the corticospinal tract on the MRI and CT with the brief review of the literatures.
Axons ; Brain Stem ; Brain* ; Cell Body ; Cerebral Infarction ; Humans ; Magnetic Resonance Imaging* ; Myelin Sheath ; Pyramidal Tracts ; Wallerian Degeneration*

PURPOSE: To determine the types of meniscal tears and type of popliteal muscle attachment in lateral disccid menisci. MATERIALS AND METHODS: MR images from 40 patients with arthroscopically proven disccid meniscal tears were reviewed. The type of capsular attachment of the popliteal muscle in these patients was compared with 100 normal controls. Fourteen men and 26 women were included in this study ranging in age from 8 to 52 yea rs. RESULTS: Disccid mensical tears were divided into five types. Arthroscopic cor- relation revealed that thirty-six cases(90%) of disccid meniscal tears were cor- rectly diagnosed using MR imaging. Peripheral tear wasthe commonest tear type occurring in 13 patients. In 9 of these the meniscal fragment was displaced. Hori- zontal tears occurred in 5, longitudinal tears in 4 and transverse tears in 2 patients. Multiple tears were present in 16 patients with the commonest combi- nation of peripheral and horizontal. Popliteal capsular attachments of disccid mensical tears were more prominent than in the normal control group. CONCLUSION: The types of tears in disccid menisci were different from normal meniscal tears. Peripheral detachment with displacement of torn segments was a very frequent finding in disccid mensical tears. Prominent capsular attachment of popliteal muscles is probably an associated finding in disccid menisci.
Classification* ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Muscles

PURPOSE: Our objective was to identify a coronary ligament of the knee joint on MR images. MATERIALS AND METHODS: We retrospectively evaluated 50 MR knee studies. Using MR imaging, the thickness and length of the anteroinferior portion of the capsule were measured and compared at the medial and lateral compartments. We also carefully dissected 5 fixed cadaveric knees and took photographs. RESULTS: The thickened synovial membrane(coronary ligament) of the anterior horn of the lateral meniscus appeared as a band of low signal intensity on MR images. On anatomic dissection of the knee joints, the inferior synovial attachment of the lateral meniscus was more redundant than the medial side. CONCLUSION: Anatomic correlation revealed that the coronary ligament contributed to the band-like structure at the anteroinferior aspect of the lateral meniscus.
Animals ; Cadaver* ; Horns ; Knee Joint* ; Knee* ; Ligaments* ; Magnetic Resonance Imaging* ; Menisci, Tibial ; Retrospective Studies

The CT findings of the acute cerebral infarction are well known. However the CT findings of early stroke within 24 hours of the onset have not been sufficiently reported. The purpose of this study is to evaluate early acute cerebral infarction on CT within 24 hours after ictus. The early and accurate CT diagnosis could lead to the appropriate therapy and improved outcome of the patients. Authors retrospectively analyzed 16 patients with early acute cerebral infarction. Acute cerebral infarction was confirmed by follow-up CT in 11 patients, SPECT in 4 patients, and MRI in 1 patient. The CT findings of early acute cerebral infarction include effacement of cortical sulci or cistern (n=16, 100%), hyperattenuation of MCA (n=3), obscuration of lentiform nucleus (n=6), loss of insular ribbon (n=6) and subtle low density in hemisphere (n=5). The most frequent findings was effacement of cortical sulci in our study, and it was though to be the most important sign of early acute cerebral infarction.
Cerebral Infarction* ; Corpus Striatum ; Diagnosis ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Retrospective Studies ; Stroke ; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to evaluate the bone age and hand anomaly in Down syndrome patients. We reviewed radiographs in 52 children and youths with Down syndrome, aged from 2 to 23 years. The characteristic findings of hand anomaly were observed in the middle phalanx of the fifth finger, with the following incidence; brachymesophalangia (44%), clinodactyly (48%), and dysmesophalangia (15%). Pseudoepiphysis (21%) was found typically at the distal end of the first metacarpal bone and proximal end of the second metacarpal bone. Up to 8.5 years of age, bone maturation was retarded and thereafter bone age accelarated in advance of chronologic age. These findings may provide valuable information relative to the diagnosis and treatment of hand anomaly in Down syndrome.
Adolescent ; Child ; Diagnosis ; Down Syndrome* ; Fingers ; Hand* ; Humans ; Incidence

PURPOSE:To evaluate the factors influencing the prognosis in avascular necrosis(AVN) of the femoral head by MR. MATERIALS AND METHODS:Radiographic and MRI findings of twenty-three patients(30 cases, aged 23-67 years) with AVN identified clinically and radiologically were evaluated. The radiography included follow up study for at least 6 months. The mean age of these patients was 43 years and M: F ratio was 20: 3. MR imaging was performed at 1. 5T unit using T1- and T2-weighted coronal and Tl-weighted sagittal and axial spin echo sequences. We categorized the changes of the femoral head on radiographic follow-ups to three grades of mild, moderate and severe. We also analyzed the changes of the signal intensity and sizes of the lesion at sagittal and coronal MR images. On MR imaging we classified the extent of AVN of the fernoral head to 2 grades according to the size of lesion. RESULTS:In the cases of mild changes in fernoral head on radiography, the mean age of the patient was 37 years and the extent of AVN was below 1/2 in eleven out of seventeen cases. In the cases of moderate changes, the mean age was 43 years and the extent was above 1/2 in five out of seven cases. In the cases of severe changes, the mean age was 60 years and the extent was above 1/2 in all 6 cases. With 95% confidence coefficient, comparisons in the age and necrosis extent revealed statistical significance in severe versus moderate changes and in severe versus mild changes. Comparisons in the change of signal intensity on T1 and T2 weighted images showed no statistical relationship between each other. CONCLUSION: We conclude that if patient is younger and has smaller extent of the AVN, bone destruction is slower that these factors may be helpful in predicting the prognosis of AVN. However, the modes of the changes of the signal intensity on T1- and T2- weighted images may not be useful in predicting the prognosis of AVN.
Follow-Up Studies ; Head* ; Humans ; Magnetic Resonance Imaging* ; Necrosis* ; Prognosis ; Radiography

Calcific myonecrosis is a rare late post-traumatic condition in which an entire single muscle is replaced by a fusiform mass with central liquefaction and peripheral calcification. The compartmental syndrome is suggested to be the underlying cause. We report a case of 70 year-old man whose right tibialis anterior and extensor hallucis longus muscle were replaced by calcific myonecrosis and treated with en-bloc resection & tendon reconstruction.
Tendons

Total knee arthroplasty(TKA) has been used for the treatment of knee joint pain, deformity, and instability caused by osteoarthritis, rheumatoid arthritis, or tuberculous arthritis, and by virtue of good results and rapid development, the procedure has been increasingly employed. With the development of total knee prosthesis, complications have also increased, however, and due to complications occurring up to six years after surgery, fusion occurs in about 2% of all replaced knees. The most common complication of TKA is loosening, followed by infection. Others are thrombosis, subluxation, dislocation and fracture, and complications may be divided into four groups: biologic, technical, specific to type of components, and associated with certain diagnosis. Where these complications occur, a patient must undergo a second procedure, but the success rate is lower than for the initial procedure. Exact etiological evaluation important clinically and radiologically. We illustrate the etiologies and radiologic characteristics of TKA complications according to classification.
Arthritis ; Arthritis, Rheumatoid ; Arthroplasty* ; Classification ; Congenital Abnormalities ; Diagnosis ; Dislocations ; Humans ; Knee Joint ; Knee Prosthesis ; Knee* ; Osteoarthritis ; Thrombosis ; Virtues

PURPOSE: To assess the accuracy of magnetic resonance(MR) arthrography in the diagnosis of anterior labral tear of the shoulder. MATERIALS AND METHODS: Between Semptember 1996 and February 2000, MR arthrography of the shoulder was performed in 281 patients with a history of shoulder pain or instability. Among this total, only 157 shoulders in 154 patients who underwent arthroscopy or open surgery 0 to 230 (average, 20.9) days after MR arthrography were included in this study; the subjects comprised of 150 males and 4 females with an average age of 23.3 years. MR arthrographs of these 154 patients were analyzed for the presence of anterior labral tears, and the findings were correlated with the arthroscopic and surgical findings. Anterior labral tear was classified as A to D according to its location, as determined by arthroscopy and surgery. (A=4 to 6 o 'clock direction, anteroinferior; B=2 to 4 o 'clock direction, central; C=12 to 2 o 'clock direction, anterosuperior; D= SLAP lesions). The retrospective analysis of MR arthrographs showing false-positive and negative findings was also undertaken. RESULTS: In the diagnosis of anterior labral tear, MR arthrography showed a sensitivity of 94%, a specificity of 90% and an accuracy of 91%. Anterior labral tears were confirmed by arthroscopy or surgery in 62 of the 157 shoulders (39%). Among 62 lesions, two (3%) were observed in area A, 32(52%) in area A+B, nine (15%) in area A+B+C, one(2%) in area A+B+D, 13(21%) in area A+B+C+D, two (3%) in area B+C, one(2%) in area B+D, and two(3%) in area C. Among ten false-positive cases, seven were focal lesions (two, three and two lesions in area A, B and C, respectively), and in the remaining three cases, located in area A+B, MR arthrography revealed thickening and deformation. All four false negatives were focal lesions (two in area A and two in area C). CONCLUSION: Other than in focal lesions, in which accuracy was relatively low, MR arthrography showed high sensitivity, specificity and accuracy in the diagnosis of anterior labral tear of the shoulder.
Arthrography* ; Arthroscopy ; Diagnosis ; Female ; Humans ; Male ; Retrospective Studies ; Sensitivity and Specificity ; Shoulder Pain ; Shoulder*