Delayed gadolinium-enhanced MRI of menisci and cartilage (dGEMRIM/dGEMRIC) in obese patients with knee osteoarthritis: Cross-sectional study of 85 obese patients with intra-articular administered gadolinium contrast.

BACKGROUND

Early cartilage changes in knee osteoarthritis (OA) can be assessed by both intravenous (i.v.) and intra-articular (i.a.) delayed gadolinium-enhanced MRI of cartilage (dGEMRIC).

PURPOSE

To examine the relationship between i.a. dGEMRIC and delayed gadolinium-enhanced MRI of menisci (dGEMRIM), and to investigate if the approach can be used to assess the morphological degeneration of menisci in obese patients with knee OA.

STUDY TYPE

Cross-sectional.

POPULATION

Eighty-five obese patients with knee OA.

FIELD STRENGTH/SEQUENCES: 1.5T. Inversion recovery sequence with four inversion times.

ASSESSMENT

T relaxation times were calculated for posterior weight-bearing femoral cartilage and the posterior horns of the menisci. Meniscus degeneration sum score (0-2) was assessed as increased signal/no signal (1/0) and tear/no tear (1/0).

STATISTICAL TESTS

T relaxation times were compared using Student's t-test. Comparison of cartilage and meniscus T relaxation times was done by regression analysis. Analysis of variance (ANOVA) was used for comparison of meniscal T relaxation times among the three summed morphological scores (0-2). Statistical analyses were performed with a level of significance at 0.05.

RESULTS

For lateral menisci, morphology sum scores of 0, 1, and 2 were found in 13, 58, and 14 patients and for medial menisci in 2, 30, and 30 patients, respectively. Mean T relaxation times were 441 msec, 480 msec, and 497 msec for cartilage, lateral menisci, and medial menisci, respectively. T relaxation times for the menisci were similar (P = 0.53), and a weak correlation was found between dGEMRIC and dGEMRIM in the lateral compartments (R = 0.26). Comparing dGEMRIM between different morphology sum scores showed no differences (P > 0.4).

DATA CONCLUSION

I.a. dGEMRIM showed no correlation between the degree of meniscal degeneration and meniscus T relaxation times. I.a. dGEMRIM do not seem to deliver useful information about meniscus degeneration to be suitable for clinical applications, but i.a. dGEMRIC may still be considered an alternative contrast-saving method for cartilage.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;48:1700-1706.