Which oblique plane is more helpful in diagnosing an anterior cruciate ligament tear?
OBJECTIVE
To evaluate the diagnostic role of additional oblique coronal and oblique sagittal magnetic resonance imaging (MRI) for an anterior cruciate ligament (ACL) tear.


METHODS
A total of 101 patients who had undergone preoperative knee MRI examinations with orthogonal and two sets of oblique images were enrolled in the study. Two radiologists evaluated the MRI images by the use of four methods: orthogonal images only (method A); orthogonal and additional oblique coronal images (method B); orthogonal and oblique sagittal images (method C); and orthogonal images with oblique coronal and sagittal images (method D). The status of the ACL (normal or tear) was determined by consensus. The sensitivity, specificity, and accuracy for an ACL tear with the use of each method were calculated in comparison with arthroscopy as the reference standard, and values were statistically analysed using the McNemar test. The diagnostic accuracies were compared using receiver operating characteristic (ROC) analysis.


RESULTS
Arthroscopy identified 10 partial ACL tears and 30 complete ACL tears. The specificities and accuracies for methods B, C, and D were significantly higher than the specificities and accuracies for method A (p<0.05). There was no significant difference in the sensitivity, specificity, and accuracy for methods B, C, and D. Diagnostic ability was not significantly different for each method, as determined by ROC analysis (p>0.05).


CONCLUSIONS
Additional oblique imaging for an ACL tear improved the specificity. Either of the oblique imaging methods is sufficient, and no further improvement in the diagnostic efficacy was achieved by simultaneous use.
Kwon
J W
JW
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710, Korea.
Yoon
Y C
YC
Kim
Y N
YN
Ahn
J H
JH
Choe
B K
BK
D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy; D002648:Child; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult