Verification of the Reliability of Sagittal MR Images in Assessment of Segmental Instability of the Wrist

PURPOSE: To determine the reliability of carpal angle measurement using sagittal wrist MR images for thediagnosis of dorsal intercalated segmental instability (DISI) or ventral intercalated segmental instability(VISI). MATERIALS AND METHODS: In ten asymptomatic adult volunteers, capitolunate, scapholunate, and radiolunate angleswere measured on lateral radiographs and five different series of sagittal MR images, and compared andstatistically analysed. The four MR series, obained in a prone position, with the wrists over the head, were asfollows : A, sagittal images parallel to the third metacarpal bone axis, in a neutral position ; B, obliquesagittal images parallel to the fourthe metacarpal axis, in a neutral position, ; C and D, sagittal imagesparallel to the third metacarpal bone axis, with the wrist at 15degree radially and ulnarly deviated positions,respectively. The fifth true sagittal MR image (E) was obtained in a supine position with the wrists locatedbeside the trunk, in a neutral position. RESULTS: In the MR series performed in the prone position, thecapitolunate and radiolunate angles measured in the series A, B and D were significantly larger than those seen onlateral radiographs. The scapholunate angle showed a statistically significant difference(p=.014) in series D,where one case showed DISI configuration at a scapholunate angle of 81degree. In other series, the angles were notsignificantly different from those seen on lateral radiographs. CONCLUSION: The lunate appears more dorsallytilted on sagittal MR images obtained in the prone position with the wrists above the head than on lateralradiographs, and a DISI configuration can be minicked. IF diagnosing wrist segmental instability by interpretingsagittal MR images without lateral radiographs, there is potential risk of misdiagnosis. It is believed that wristpositioning is crucial for the correct measurement of angles.

Volumetric measurement of the inflamed synovium of rheumatoid wrist joint for the evaluation of synovitis and remission

PURPOSE: To evaluate the changes and remission of disease activity with changes in inflamed synivial volumes of rheumatoid joints after therapy. MATERIALS AND METHODS: Seven rheumatoid arthritis patients who had been treated with antiinflammatory drugs were followed up. Using NIH imaging and a segmentation technique, pre- and post-enhanced images were measured in subtracted images. Intra- and interobserver variation were evaluated by two radiologists(A and B), using two independent measurements. For comparison, the cases were assigned to one of two groups : remission and non-remission. Changes in ESR and total joint counts(TJC) after therapy were compared with inflamed synovial volumes. RESULTS: Intraobserver variations were 3.2% and 2.7% in A and B, respectively, interobserver variation between A and B was 7.1%. Changes in inflamed synovial volumes correlated well with those in ESR (r=0.88, p<0.009) and TJC (r=0.78, p<0.037) after therapy. Changes between the remission and non-remission group were insignificant, however. CONCLUSION: Changes in inflamed synovial volumes reflect those in the activity of rheumatoid arthritis between pre- and post- treatment. This technique may be used as a tool for predicting therapeutic response in rheumatoid arthritis cases. Changes in inflamed synovial volumes are of limited value, however, in predicting the remission of rheumatoid arthritis after therapy.

Volumetric measurement of the inflamed synovium of rheumatoid wrist joint for the evaluation of synovitis and remission

PURPOSE: To evaluate the changes and remission of disease activity with changes in inflamed synivial volumes of rheumatoid joints after therapy. MATERIALS AND METHODS: Seven rheumatoid arthritis patients who had been treated with antiinflammatory drugs were followed up. Using NIH imaging and a segmentation technique, pre- and post-enhanced images were measured in subtracted images. Intra- and interobserver variation were evaluated by two radiologists(A and B), using two independent measurements. For comparison, the cases were assigned to one of two groups : remission and non-remission. Changes in ESR and total joint counts(TJC) after therapy were compared with inflamed synovial volumes. RESULTS: Intraobserver variations were 3.2% and 2.7% in A and B, respectively, interobserver variation between A and B was 7.1%. Changes in inflamed synovial volumes correlated well with those in ESR (r=0.88, p<0.009) and TJC (r=0.78, p<0.037) after therapy. Changes between the remission and non-remission group were insignificant, however. CONCLUSION: Changes in inflamed synovial volumes reflect those in the activity of rheumatoid arthritis between pre- and post- treatment. This technique may be used as a tool for predicting therapeutic response in rheumatoid arthritis cases. Changes in inflamed synovial volumes are of limited value, however, in predicting the remission of rheumatoid arthritis after therapy.

Clinical Significance of Dynamic Magnetic Resonance imaging in the Evaluation of Wrist Joint in Rheumatoid Arthritis

PURPOSE: To assess the role of contrast-enhanced dynamic Magnetic Resonance Imaging in evaluating disease activity of rheumatoid arthritis. MATERIALS AND METHODS: Forty-seven wrist joints with rheumatoid arthritis were examined prospectively. coronal images of the wrist were obtained using fat-suppression Fast multi-planar spoiled gradient recalled(FMPSPGR) acquisition in the steady state ; TR/TE=102/6.4m sec, flip angle=60.4 slices persequence, FOV=8cm, matrix=256X192 at 1.5 Tesla. Scans were carried out once before and five to eight times after an intravenous Gd-DPTA injection, at 30-second-intervals. The enhancement of synovium were measured, the enhancement ratio was calculated(postcontrast SNR/precontrast SNR) and time-enhancement ratio curves were plotted patients were divided into three groups according to the ratio of inital to peak enhancement: less than 30%; 30-80%; morethan 80%. Differences among the three groups were statistically tested using clinical indices and laboratory data as variables. RESULTS: Comparing one group with another, there were no significant differences in clinical indices and laberatory data except for the parameter of grip strength. CONCLUSION: Enhancement pattern measured in a single wrist joint was not comparable to a clinical index in predicting disease activity in rheumatoid arthritis.

MR imaging of Kienbock's Disease

PURPOSE: To evaluate the MRI appearance of Kienbock's disease and correlate this with radiographic findings. MATERIALS AND METHODS: Thirteen clinically confirmed cases of 12 patients with kienbock's disease wereretrospectively reviewed. The significance of signal intensity and pattern of Kienbock's disease on MR images was evaluated and the findings on MR images were compared with radiographic stages classified by Lichtman. Enhanced MR images were abtained in four cases. RESULTS: Lichtman's stage I accounted for one case; stage II, two; stage III, eight; stage IV, two. On T1-weighted MR images, the lunate showed focal low signal intensity in the stage I caseand in one of the two stage II case. Eleven wrists demonstrated a generalized loss of lunate signal. On T2-weighted images, the stage I case showed focal high signal intensity. In stage II, one showed focal low signal intensity and the other exhibited generalized low signal intensity with a high spot area. In stage III, five ofeight cases showed generalized low signal intensity, and one demonstrated high signal intensity. Two showed a high spot area within the generalized low signal intensity. In stage IV, one showed generalized low signal intensity and the other exhibited high signal intensity. No enhancement was seen in the three lesions with focal orgeneralized low signal intensity both on T1 and T2-weighted images. Conversely, one lesion with low signalintensity on T1-weighted imaes and high signal intensity on T2-weighted images showed contrast enhancement. CONCLUSION: Low signal intensity of the lunate on T1-weighted images is a consistent findings of Kienbock's disease. However, further studies such as follow-up MRIs, or pathologic correlation studies and MR contrast enhancement studies will be necessary to evaluate the sighificance of high signal intensity on T2-weighted images.