Ankle MRI for Anterolateral Soft Tissue Impingement: Increased Accuracy with the Use of Contrast-Enhanced Fat-Suppressed 3D-FSPGR MRI

OBJECTIVE: To validate the use of contrast-enhanced (CE) fat-suppressed three-dimensional (3D) fast gradient-recalled acquisition in the steady state with radiofrequency spoiling (FSPGR) magnetic resonance imaging (MRI) for the diagnosis of anterolateral soft tissue impingement of the ankle, as compared to the use of routine ankle MRI. MATERIALS AND METHODS: Contrast-enhanced fat-suppressed 3D-FSPGR MRI and routine MRI scans were retrospectively reviewed for 45 patients with arthroscopically proven anterolateral impingement. In addition, scans were reviewed in 45 control subjects with diagnoses other than impingement. Two radiologists independently reviewed the two sets of images in random order. Using areas (Az) under the receiver operating characteristic curve (ROC), we compared the depiction of anterolateral soft tissue impingement in the two sets of images. RESULTS: The overall accuracy for lesion characterization was significantly higher (p < 0.05) using the CE fat-suppressed 3D-FSPGR MR images (Az = 0.892 and 0.881 for reader 1 and 2, respectively) than using the routine MR images (Az = 0.763 and 0.745). The use of CE fat-suppressed 3D-FSPGR MRI enhanced impingement depiction in most cases. However, in cases with a thickened non-enhancing scar or joint effusion, the routine images better depicted a soft tissue mass that intruded into anterolateral gutter than the CE images. CONCLUSION: The use of CE fat-suppressed 3D-FSPGR MRI of the ankle allows a more accurate assessment of anterolateral soft tissue impingement of the ankle, as compared to the use of routine MRI.

Fibular Hemimelia: A Case Report

Fibular hemimelia is the most common congenital absence or hypoplasia of long bone. In addition to fibular absence or hypoplasia, this entity also includes various combined abnormalities of the lower limbs. We present here three cases of fibular hemimelia who underwent diagnosis and treatment in our hospital. Wee especially focus on the imaging findings of the plain radiographs, and we compare them with the findings found at another presentation.

Subtalar Coalition: Usefulness of the C Sign on Lateral Radiographs of the Ankle

PURPOSE: To assess the usefulness of the talocalcaneal C sign in the diagnosis of subtalar coalition, as seen on lateral radiographs of the ankle. MATERIALS AND METHODS: Lateral radiographs of 12 ankles in 11 patients were included in this study. Twelve subtalar coalitions were confirmed by surgery (n=6), or by CT and/or MR (n=6). The presence of the talocal-caneal C sign on lateral ankle radiographs was determined. RESULTS: The C sign was continuous in six feet and interrupted in the remaining six. Subtalar coalition occurred simultaneously in the middle and posterior subtalar joints in two cases, the posterior subtalar joint only in six, and in the middle subtalar joint only in four. In six cases confirmed at surgery, subtalar coalitions consisted of both synostosis and non-osseous fusion (synchondrosis and/or syndesmosis) and in one case of middle subtalar coalition, there was a bony bridge. The remaining six cases, confirmed at CT or MRI, involved both synostosis and non-osseous fusion (n=1) or non-osseous fusion only (n=5). CONCLUSION: In the diagnosis of subtalar coalition, the talocalcaneal C sign, seen on lateral radiographs of the ankle, is a useful indicator.