Magnetic resonance imaging of anterior cruciate ligament tears: evaluation of standard orthogonal and tailored paracoronal images.
OBJECTIVE
To evaluate the three standard orthogonal imaging planes and a paracoronal imaging plane for anterior cruciate ligament (ACL) tears.


METHODS
Ninety patients (91 knees; 29 F and 61 M) aged between 15 and 84 years (mean 36.9 +/- 16.4 years) underwent magnetic resonance imaging (MRI) of the knee prior to arthroscopy. At surgery, 32 knees had an intact ACL, 4 a partial tear, and 55 a complete ACL tear. In all patients, axial, sagittal, coronal, and paracoronal T2-weighted turbo-SE images were acquired. The ACL was classified as intact, partially, or completely torn. Partial and complete tears were combined for statistical evaluation.


RESULTS
Partial ACL tears (four cases) were not correctly diagnosed at MRI except in one knee by one observer on coronal images. Sensitivity in detecting ACL tears was 95%/63% (reader1/reader2) in the axial, 93%/95% in the sagittal, 93%/86% in the coronal, and 100%/93% in the paracoronal plane. Specificity was 75%/81% in the axial, 72%/81% in the sagittal, 78%/94% in the coronal, and 78%/88% in the paracoronal plane.


CONCLUSIONS
ACL tears can be diagnosed accurately with each of the standard orthogonal planes. Based on reader confidence and interobserver agreement paracoronal images may be useful in equivocal cases.
Duc
S R
SR
MR Research Group, Institute of Radiology, Cantonal Hospital, Winterthur, Switzerland. Sylvain.duc@balgrist.ch
Zanetti
M
M
Kramer
J
J
Käch
K P
KP
Zollikofer
C L
CL
Wentz
K U
KU
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000070598:Anterior Cruciate Ligament Injuries; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged