Feasibility of T2 mapping for the evaluation of hip joint cartilage at 1.5T using a three-dimensional (3D), gradient-echo (GRE) sequence: a prospective study

• Published in: Magnetic resonance in medicine 2009-10, Vol.62 (4), p.896-901
• Main Authors: Bittersohl, Bernd, Hosalkar, Harish S, Hughes, Tim, Kim, Young-Jo, Werlen, Stefan, Siebenrock, Klaus A, Mamisch, Tallal C
• Format: Article
• Language: English
• Subjects: Algorithms; Cartilage, Articular - pathology; Echo-Planar Imaging - methods; Feasibility Studies; Female; Hip Joint - anatomy & histology; Hip Joint - pathology; Humans; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Imaging, Three-Dimensional - methods; Joint Diseases - pathology; Male; Middle Aged; Reproducibility of Results; Sensitivity and Specificity; Young Adult
• ISSN: 1522-2594
• DOI: 10.1002/mrm.22096

This study defines the feasibility of utilizing three-dimensional (3D) gradient-echo (GRE) MRI at 1.5T for T(2)* mapping to assess hip joint cartilage degenerative changes using standard morphological MR grading while comparing it to delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). MRI was obtained from 10 asymptomatic young adult volunteers and 33 patients with symptomatic femoroacetabular impingement (FAI). The protocol included T(2)* mapping without gadolinium-enhancement utilizing a 3D-GRE sequence with six echoes, and after gadolinium injection, routine hip sequences, and a dual-flip-angle 3D-GRE sequence for dGEMRIC T(1) mapping. Cartilage was classified as normal, with mild changes, or with severe degenerative changes based on morphological MRI. T(1) and T(2)* findings were subsequently correlated. There were significant differences between volunteers and patients in normally-rated cartilage only for T(1) values. Both T(1) and T(2)* values decreased significantly with the various grades of cartilage damage. There was a statistically significant correlation between standard MRI and T(2)* (T(1)) (P < 0.05). High intraclass correlation was noted for both T(1) and T(2)*. Correlation factor was 0.860 to 0.954 (T(2)*-T(1) intraobserver) and 0.826 to 0.867 (T(2)*-T(1) interobserver). It is feasible to gather further information about cartilage status within the hip joint using GRE T(2)* mapping at 1.5T.