Abstract
Background: Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures.
Purpose: To investigate the contrast dynamics in hyaline and fibrous cartilage of the glenohumeral joint after intraarticular injection of gadopentetate dimeglumine.
Material and Methods: Transverse T1 maps were acquired on a 1.5T scanner before and after intraarticular injection of 2.0 mmol/l gadopentetate dimeglumine in five cadaveric shoulders using a dual flip angle three-dimensional gradient echo (3D-GRE) sequence. The acquisition time for the T1 maps was 5 min 5 s for the whole shoulder. Measurements were repeated every 15 min over 2.5 hours. Regions of interest (ROIs) covering the glenoid cartilage and the labrum were drawn to assess the temporal evolution of the relaxation parameters.
Results: T1 of unenhanced hyaline cartilage of the glenoid was 568±34 ms. T1 of unenhanced fibrous cartilage of the labrum was 552±38 ms. Significant differences (P=0.002 and 0.03) in the relaxation parameters were already measurable after 15 min. After 2 to 2.5 hours, hyaline and fibrous cartilage still demonstrated decreasing relaxation parameters, with a larger range of the T1(Gd) values in fibrous cartilage. T1 and ▵R1 values of hyaline and fibrous cartilage after 2.5 hours were 351±16 ms and 1.1±0.09 s−1, and 332±31 ms and 1.2±0.1 s−1, respectively.
Conclusion: A significant decrease in T1(Gd) was found 15 min after intraarticular contrast injection. Contrast accumulation was faster in hyaline than in fibrous cartilage. After 2.5 hours, contrast accumulation showed a higher rate of decrease in hyaline cartilage, but neither hyaline nor fibrous cartilage had reached equilibrium.