Jacob J. Visser MS, Abstract Co-Author: Nothing to Disclose

Annick C. Weustink MD, PhD, Abstract Co-Author: Nothing to Disclose

Edwin H.G. Oei MD, PhD, Presenter: Nothing to Disclose

Galied S. Muradin MD, Abstract Co-Author: Nothing to Disclose

To determine whether 2 millimeter slice thickness on knee MRI has additional value for evaluating menisci and cruciate ligaments in symptomatic patients.

74 consecutive patients undergoing knee arthroscopy following MRI of the knee from January 1, 2011 until November 1, 2012 were included retrospectively. A routine clinical MRI protocol was acquired with 3 millimeter (mm) slice thickness followed by additional sagittal and axial 2 mm proton density (PD) weighted sequences. 2 sets of MR sequences per patient were created: routine protocol with 3 mm only and the extended protocol with additional 2 mm sequences. All MR imaging studies were reviewed independently by two musculoskeletal radiologists for presence of ligament and meniscal tears. Sensitivity and specificity of the routine and extended MRI protocol in the detection of meniscal tears and cruciate ligament tears were calculated with arthroscopy used as the reference standard. Logistic regression analysis was used to assess the additional value of the 2 mm PD-slices.

The extended MR imaging protocol with 2 mm slices had higher sensitivity than the routine MR imaging protocol for the detection of meniscal tears (94% versus 90%) and similar specificity (94% and 95% respectively). Sensitivity for detection of medial meniscal tears was 98% with the extended protocol versus 93% with the routine protocol with no difference in specificity (88%). For detection of lateral meniscal tears, both sensitivity and specificity were higher for the extended MR imaging protocol (89 versus 85% and 100 versus 98% respectively). Sensitivity for anterior cruciate ligament tears was 90% for the extended MR imaging protocol versus 92% for the routine imaging protocol, whereas the specificity was 83% for the extended imaging protocol versus 75%. Logistic regression analysis showed statistically significant additional value for the extended versus the routine MR imaging protocol in the detection of meniscal and anterior cruciate ligament tears (P<0.01).

An extended knee MRI protocol with 2 mm slice thickness has additional value in the detection of meniscal and anterior cruciate ligament tears.

Routine knee MRI protocols are often based on sequences with 3-4 millimeter slices. Two millimeter sequences improve diagnostic performance and may be an alternative to 3D isotropic scanning.

Visser, J, Weustink, A, Oei, E, Muradin, G, MRI of the Knee—Do 2 Millimeter Slices Improve Diagnostic Performance?.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13019360.html