Purpose: To establish the reproducibility of a standardized region of interest (ROI) drawing procedure in delayed gadolinium‐enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC).
Material and Methods: A large ROI in lateral and medial femoral weight‐bearing cartilage was drawn in images of 12 healthy male volunteers by 6 investigators with different skills in MRI. The procedure was done twice, with a 1‐week interval. Calculated T1‐values were evaluated for intra‐ and interobserver variability.
Results: The mean interobserver variability for both compartments ranged between 1.3% and 2.3% for the 6 different investigators without correlation to their experience in MRI. Post‐contrast intra‐observer variability was low in both the lateral and the medial femoral cartilage, 2.6% and 1.5%, respectively. The larger variability in lateral than in medial cartilage was related to slightly longer and thinner ROIs.
Conclusion: Intra‐observer variability and interobserver variability are both low when a large standardized ROI is used in dGEMRIC. The experience of the investigator does not affect the variability, which further supports a clinical applicability of the method.
