[MRI of the lateral ankle ligaments: value of three-dimensional orientation].
OBJECTIVE
To determine the three-dimensional orientation of the lateral ankle ligaments with MRI.


METHODS
Twenty healthy volunteers without previous injury to the ankle were included in the study. With the right ankle in the normal anatomic position stabilized in a splint, coronal T2-weighted spin-echo sequences (TSE) were obtained. The three-dimensional orientation was determined by placing paths through the ligaments and by measuring the angles between corresponding tangents and the three main imaging planes.


RESULTS
Using the calculated angles, full-length visualization of the lateral ligaments of the ankle was achieved. The angles deviating from the axial imaging plane were 18.0 degrees for the anterior talofibular ligament, 52.3 degrees for the calcaneofibular ligament and 28.2 degrees for the posterior talofibular ligament.


CONCLUSIONS
MRI enables the exact determination of the three-dimensional orientation of the lateral ankle ligaments. Orienting the imaging planes according to the calculated angular deviation allows the full-length visualization of the ligaments and is the basis for optimal imaging of the lateral ankle ligaments.
Mayerhöfer
M E
ME
Univ.-Klinik für Radiodiagnostik, Klinische Abteilung Radiodiagnostik für Chirurgische Fächer, Universität Wien, Vienna, Austria.
Breitenseher
M J
MJ
D000328:Adult; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D017844:Lateral Ligament, Ankle / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012016:Reference Values; D012680:Sensitivity and Specificity