Acetabular Cartilage Assessment in Patients with Femoroacetabular Impingement by Using T2* Mapping with Arthroscopic Verification

Abstract

The patient-specific acetabular projection with a T2* mapping overlay enabled good anatomic localization of cartilage damage defined with a T2* threshold of 28 msec and less.

T2* Relaxation Time of Acetabular and Femoral Cartilage With and Without Intraarticular Gadopentetate Dimeglumine in Patients With Femoroacetabular Impingement

“…To our knowledge, investigation of T2* relaxation time of acetabular cartilage with and without Gd-DTPA 2- has only been reported in our previous study and at that in a limited number of cases [10]. A systematic evaluation of the effect of Gd-DTPA 2- on T2* relaxation in cartilage is currently lacking.…”

“…Preliminary results using T2* mapping in FAI indicate that one can distinguish normal from abnormal hip articular cartilage [6-10], while standard MR imaging lacks diagnostic accuracy for the evaluation of cartilage lesions [11]. The advantages of T2* relaxation time mapping in hip joint cartilage include wide availability on clinical scanners, shorter imaging time, independent characterization of acetabular and femoral cartilage, high image resolution, and high signal-to-noise ratio (SNR) as compared to other quantitative methods, such as T1 or T2 mapping [9].…”

Magnetic Resonance Imaging of the Sacroiliac Joints in Patients with Suspected Spondyloarthritis – Comparison of Turbo Spin-Echo and Gradient-Echo Sequences for the Detection of Structural Alterations

“…The sacral joint surface of the sacroiliac joints is comprised of hyaline cartilage and the iliac joint surface of fibrous cartilage which represents the particularly vulnerable entheseal joint side [13]. The GRE technique has become increasingly established in musculoskeletal MRI for dedicated cartilage visualization [14,15]. However, unenhanced non-fat-saturated T1-weighted TSE sequences should also be part of the examination protocol for sacroiliac joints to rule out pathological bone marrow changes, e. g. tumor infiltrations or fractures.…”

Femoroacetabular Impingement

“…These changes lead to shortening of the T2* times. Using these biochemical MRI techniques studies have reported (a) lower T1Gd values from dGEMRIC in the anterosuperior region in cam-type FAI, lower T1Gd values globally in pincer-type FAI, and negative correlations between alpha angle and T1Gd of the anterosuperior region (75-78), (b) higher T1ρ and T2 of both the femoral and acetabular cartilage in subjects with symptomatic FAI compared to controls, especially in the anterosuperior region (79), and (c) lower T2* in regions of acetabular cartilage damage identified during arthroscopy in symptomatic FAI subjects without radiographic OA (74) and in subjects with cartilage lesions (80)(81)(82)(83).…”

“…In the non-contrast techniques, a loss of proteoglycans is detected as an increase in cartilage T1ρ relaxation times and a disruption of the collagen orientation with increased water content is detected as an increase in the cartilage T2 relaxation times (71)(72)(73). T2* is similar to T2 but is more sensitive to susceptibility artifacts; and hence may be able to detect the deposition of calcium hydroxyapatite and fibrocartilagenous transformation at the osteochondral junction (74). These changes lead to shortening of the T2* times.…”