Anterolateral ankle impingement: diagnostic performance of MDCT arthrography and sonography.

OBJECTIVE: The purpose of our study was to compare the diagnostic performance of CT arthrography and sonography in the diagnosis of anterolateral ankle impingement. SUBJECTS AND METHODS: Fifty-one patients with clinically suspected anterolateral ankle impingement prospectively underwent ankle sonography and CT arthrography, immediately followed by an additional ankle sonography examination to evaluate a potential joint effusion impact on diagnostic performance. CT arthrographic findings as well as sonographic findings before and after arthrography were correlated to subsequent arthroscopic appearance in 41 patients. The diagnostic performance of CT arthrography and sonography before and after joint injection was calculated using arthroscopy as the reference standard and compared using McNemar tests. RESULTS: The sensitivity and specificity of sonography were respectively 77% and 57% before joint injection and 85% and 71% after joint injection. Positive Doppler masses were found to be anterolateral impingements at arthroscopy in all cases (10/10), and masses of hyperechoic appearance were found not to be anterolateral impingements in all cases (3/3). The sensitivity and specificity of CT arthrography in the diagnosis of anterolateral impingement were respectively 97% and 71%. The performances of CT arthrography and ankle sonography in the diagnosis of anterolateral ankle impingement were significantly different (p = 0.006). CONCLUSION: CT arthrography is quite accurate and superior to ankle sonography in the diagnosis of anterolateral impingement. The diagnostic performance of sonography is limited, but positive Doppler appearance and hyperechogenicity, when present, could help to exclude or confirm the diagnosis.

Early characterization of atherosclerotic coronary plaques with multidetector computed tomography in patients with acute coronary syndrome: a comparative study with intravascular ultrasound.

We compared 16-slice computed tomography (CT) with intravascular ultrasound (IVUS) in their ability to identify the culprit lesion, and to assess plaque characterization and vascular remodelling in acute coronary syndrome (ACS). Twenty patients were prospectively studied. Coronary plaque identification and characterization were compared using 16-slice CT and 40-MHz catheter-based IVUS. Minimum lumen area (MLA), cross-sectional vessel area (CVA) and vessel remodelling were determined for each comparable lesion. One hundred and sixty-nine segments were compared and 84 plaques analysed. Sixteen-slice CT detected 95% of culprit lesions (19/20). No feature suggestive of plaque rupture was detected by 16-slice CT. Attenuation measurements within all lesions revealed different values for hypoechoic (38 +/- 33 HU), hyperechoic (94 +/- 44 HU), and calcified plaques (561 +/- 216 HU), (P < 0.001). Agreement between 16-slice CT and IVUS on measuring MLA and CVA was evaluated using Bland-Altman analysis. Pearson and intra-class coefficient (ICC) were 0.81 and 0.70 for MLA, and 0.81 and 0.36 for CVA, for 16-slice CT and IVUS, respectively. Agreement between both techniques for vessel positive remodelling was moderate (kappa = 0.54, P < 0.001). Sixteen-slice CT has shown moderate accuracy in quantifying and characterizing coronary plaques compared with IVUS. Spatial resolution of 16-slice CT remains a major limitation, however, to accurately assess the complex lesions involved in ACS.

Predictive value of noninvasive coronary angiography with multidetector computed tomography to detect significant coronary stenosis before valve surgery.

Quantitative coronary angiography (QCA) is routinely performed before valve surgery for severe acquired valvular disease. This technique is relatively invasive, especially in a population with an average risk for significant coronary stenosis. Multidetector computed tomography (MDCT) coronary angiography allows the noninvasive evaluation of the coronary anatomy. The aim of this prospective study was to evaluate the predictive values of 16-slice MDCT in the detection of significant coronary stenosis (> or = 50%) before valve surgery in patients with severe valvular disease without known coronary artery disease and average risk, in comparison with conventional QCA. Forty patients with severe acquired valvular disease (mean age 70 +/- 8.6 years; 20 women; 27 with severe aortic stenosis) underwent coronary MDCT 2 days before cardiac catheterization with QCA. The mean heart rate was 64.7 +/- 8.8 beats/min (range 41 to 78). Four hundred fifty-eight of 600 coronary artery segments (77.3%) were considered assessable by MDCT. In a per-segment analysis, the sensitivity of MDCT for the detection of significant coronary lesions > or = 50% was 77.7%, the specificity was 98%, the positive predictive value was 42.4%, and the negative predictive value was 99%. The main cause of false-positive or false-negative results or nonassessable evaluations was severe coronary calcification. In a per-patient analysis, in comparison with QCA, MDCT correctly classified 33 of 40 patients (82.5%). In conclusion, in patients with an average risk for coronary stenosis before valve surgery, MDCT coronary angiography detected significant obstructive coronary artery disease, with a 99% NPV.