Multidetector CT arthrography of the wrist joint: how to do it.

With its exquisite spatial resolution, multidetector computed tomographic (CT) arthrography of the wrist is a valuable tool for the diagnosis and evaluation of a wide spectrum of articular disorders. Traumatic tears of the interosseous ligaments can be classified as complete or incomplete and as partial- or full-thickness tears at multidetector CT arthrography and can also be differentiated from asymptomatic degenerative lesions. In addition, tears of the triangular fibrocartilage complex can be differentiated according to their location. A tailored contrast material injection technique and multiplanar reformation are recommended for optimal assessment of these structures. Multidetector CT arthrography is also remarkably effective in demonstrating cartilage and bone abnormalities, many of which cannot be depicted with other imaging techniques. The chief limitation of multidetector CT arthrography lies in the evaluation of soft-tissue abnormalities, which may benefit from the addition of other imaging techniques such as ultrasonography or magnetic resonance imaging. A basic knowledge of the relevant anatomy, pathophysiologic features, and imaging technique is mandatory for obtaining high-yield diagnostic information concerning the wrist joint. (c) RSNA, 2008.

Anterior approach for knee arthrography: tolerance evaluation and comparison of two routes.

PURPOSE: To prospectively evaluate patient tolerance and technical success of the anterior knee puncture approach for arthrography by using two different routes. MATERIALS AND METHODS: The study had Strasbourg University Hospital review board approval. Informed consent was obtained from all patients (and from their parents, if patients were minors). In 159 patients (89 male and 70 female; age range, 14-82 years; mean age, 44.3 years +/- 16 [standard deviation]) referred for computed tomographic (CT) arthrography, anterior puncture of the knee was performed by using an anterolateral (n = 73) or anterior paramedian (n = 86) route. For each patient, body mass index, absolute pain on a visual analog scale, relative pain (compared with anticipatory pain), and history of previous knee arthrography were recorded. A score reflecting the technical success of the procedure was established by using a five-point scale. Factors influencing tolerance and technical success were analyzed with Pearson correlation coefficients. Student t and chi2 tests were used to compare the two routes. RESULTS: The anterior approach for knee arthrography was well tolerated (mean visual analog scale score, 12.9 +/- 16.4) and technically successful (mean technical success score, 1.36 +/- 0.84) in most cases. Absolute pain was not influenced by age, sex, or body mass index and was only weakly correlated (r = 0.33) with the technical success score. The technical success score weakly correlated (r = 0.23) with the body mass index. A slight but significant reduction in absolute (P < .05) and relative (P < .01) pain was observed for the anterolateral route compared with the anterior paramedian route, while no significant differences (P > .05) were found for other parameters, including the technical success score. CONCLUSION: The anterior approach for knee arthrography is technically successful and well tolerated, particularly when an anterolateral route is used.

Wrist ligament tears: evaluation of MRI and combined MDCT and MR arthrography.

OBJECTIVE: The purpose of this study was to evaluate the performance of MRI and a combination of MDCT arthrography and MR arthrography in the diagnosis of tears and cartilage abnormalities of the wrist ligaments. SUBJECTS AND METHODS: The feasibility of combining MDCT arthrography and MR arthrography and performing them with an optimized contrast solution was evaluated in vitro and in vivo. Forty-five consecutively enrolled subjects with suspected wrist ligament tears underwent MRI and a combined MDCT and MR arthrographic procedure. Two observers reviewed the images for evidence of tears and cartilage abnormalities of the scapholunate and lunotriquetral ligaments and triangular fibrocartilaginous complex. Interobserver agreement was determined with kappa statistics, and the diagnostic accuracy of each technique was calculated. RESULTS: A 1:1 solution of 2.5 mmol/L tetraazacyclododecanetetraacetic acid (DOTA)-gadolinium and 300 mg I/mL iopamidol provided adequate contrast enhancement for both in vitro and in vivo MDCT arthrographic and MR arthrographic images. Interobserver agreement was substantial for MRI (kappa = 0.61) and MR arthrography (kappa = 0.71) and almost perfect for MDCT arthrography (kappa = 0.93). The sensitivity and specificity of MRI, MDCT arthrography, and MR arthrography for tears of the scapholunate ligament were 59% and 70%, 95% and 96%, and 68% and 87% for the first observer and 77% and 83%, 95% and 100%, and 77% and 87% for the second observer. For tears of the lunotriquetral ligament, these values were 30% and 94%, 100% and 94%, and 60% and 97% for the first observer and 50% and 97%, 90% and 100%, and 50% and 94% for the second observer. The three techniques appeared equivalent for complete tears of the scapholunate and lunotriquetral ligaments, but partial tears were significantly better visualized with MDCT arthrography. The sensitivity and specificity of MRI, MDCT arthrography, and MR arthrography for triangular fibrocartilaginous complex tears were 27% and 100%, 100% and 100%, and 82% and 100% for the first observer and 45% and 100%, 100% and 100%, and 82% and 100% for the second observer. For cartilage abnormalities, these values were 30% and 100%, 100% and 100%, and 30% and 100% for the first observer and 10% and 100%, 100% and 100%, and 40% and 100% for the second observer. CONCLUSION: MDCT arthrography appears more accurate than MRI and MR arthrography, particularly for discerning partial tears of the scapholunate and lunotriquetral ligaments that do not necessitate surgical therapy.

Should plain X-rays be routinely performed after blunt knee trauma? A prospective analysis.

BACKGROUND: We tested the hypothesis that it was possible to decrease the number of performed x-rays after a knee trauma without delayed fracture diagnosis by using the Ottawa knee rules. METHODS: Patients had routine x-rays of the injured knee during the first stage of the study and selective x-rays during the second stage. All patients were followed up to 6 months after the trauma. RESULTS: 138 patients were included in the first stage; 57 had negative Ottawa criteria: no fracture was observed; following the Ottawa rules, 41% of the x-rays could have been avoided. 178 patients were included in the second stage; 63 patients had negative Ottawa criteria: no fracture was diagnosed during the whole follow-up; 35% of the x-rays have been avoided. CONCLUSIONS: Ottawa rules allowed decreasing the number of x-rays performed after a knee trauma by 35% with a sensitivity for a knee fracture detection of 100%.