Current knowledge and importance of dGEMRIC techniques in diagnosis of hip joint diseases

Abstract

Accurate assessment of early hip joint cartilage alterations may help optimize patient selection and follow-up of hip joint preservation surgery. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is sensitive to the glycosaminoglycan content in cartilage that is lost early in the development of osteoarthritis (OA). Hence, the dGEMRIC technique holds promise for the development of new diagnostic and therapeutic procedures. However, because of the location of the hip joint deep within the body and due to the fairly thin cartilage layers that require high spatial resolution, the diagnosis of early hip joint cartilage alterations may be problematic. The purpose of this review is to outline the current status of dGEMRIC in the assessment of hip joint cartilage. A literature search was performed with PubMed, using the terms "cartilage, osteoarthritis, hip joint, MRI, and dGEMRIC", considering all levels of studies. This review revealed that dGEMRIC can be reliably used in the evaluation of early stage cartilage pathology in various hip joint disorders. Modifications in the technique, such as the operation of three-dimensional imaging and dGEMRIC after intra-articular contrast medium administration, have expanded the range of application. Notably, the studies differ considerably in patient selection and technical prerequisites. Furthermore, there is a need for multicenter prospective studies with the required technical conditions in place to establish outcome based dGEMRIC data to obtain, in conjunction with clinical data, reliable threshold values for normal and abnormal cartilage, and for hips that may benefit from conservative or surgical treatment.

Protocol for a multi-centre randomised controlled trial comparing arthroscopic hip surgery to physiotherapy-led care for femoroacetabular impingement (FAI): the Australian FASHIoN trial

“…In addition, the 12-month change in standardised dGEMRIC z-scores for the acetabular and femoral head cartilage ROIs at the chondrolabral junction will be analysed, using the central femoral cartilage ROI as an internal control [ 31 , 32 ]. The dGEMRIC technique has been proven reliable for quantification and detection of changes in the glycosaminoglycan (GAG) content of the hip joint cartilage [ 33 – 36 ]. Since the loss of GAG in cartilage is an early OA-related change [ 37 ], dGEMRIC enables the likelihood of future OA development to be compared between treatment methods after a relatively short period.…”

Standard and Advanced Imaging of Hip Osteoarthritis. What the Radiologist Should Know

“…There is a debate whether precontrast T1-mapping (T1 0 ) in addition to postcontrast T1-mapping (T1 Gd ) is necessary, or if postcontrast evaluation alone provides accurate information in the native hip; however, precontrast images are recommended after cartilage repair because T1 0 values may differ significantly from normal cartilage. 88,89 The time required for a dGEMRIC examination remains one of its major disadvantages, as well as the inherent cost from gadolinium utilization. Initial dGEMRIC investigations used T1-weighted inversion recovery sequences due to widespread availability and ease of implementation, but they suffered from long acquisitions, motion artifacts, and low resolution, often requiring femoral and acetabular articular cartilage to be evaluated as a single unit, rather than distinct measurable tissues.…”

“…88 More current techniques utilize 3D sequences that can evaluate local as well as widespread cartilage changes, and they were shown to be at least as reliable as conventional 2D techniques. 89 In the hip, dGEMRIC has been applied to FAI, DDH, and Legg-Calvé-Perthes (LCP) disease to assess cartilage quality. [88][89][90][91][92][93][94] Kim and colleagues observed measurable decreases in T1 values (dGEMERIC index) with worsening degrees of hip dysplasia, from 570 ms (no dysplasia) to 420 ms (severe dysplasia).…”

“…89 In the hip, dGEMRIC has been applied to FAI, DDH, and Legg-Calvé-Perthes (LCP) disease to assess cartilage quality. [88][89][90][91][92][93][94] Kim and colleagues observed measurable decreases in T1 values (dGEMERIC index) with worsening degrees of hip dysplasia, from 570 ms (no dysplasia) to 420 ms (severe dysplasia). 91 In a study by Mamisch and colleagues, dGEMRIC index values were also decreased in patients with cam and pincer deformities at 488 ms and 462 ms, respectively, compared with asymptomatic volunteers at 643 ms. 92 Stelzeneder and colleagues directly compared dGEMRIC indices between FAI and DDH hips and found slightly lower values in FAI (527 ms) than DDH (557 ms), but they found no statistically significant difference.…”

Quantitative 3D imaging parameters improve prediction of hip osteoarthritis outcome

“…Assessment of radiographs and, in most circumstances, MRI relies on 2D images being interpreted by human observers to give a semiquantitative score or grade of disease: for example the KL system grades from 0 to 4 (equating to none-possible-mild-moderate-severe) 8 . Beyond morphological cartilage thickness measurement 14 , other quantitative MRI techniques such as compositional T2, T1rho, ultrashort echo and dGEMRIC (delayed gadolinium enhanced MRI of cartilage) time measurements have been developed, but their role in prognostication is yet to be clearly defined 15,16 . Semiquantitative MRI scoring systems have also been developed for the assessment of disease at the hip (HOAMS) and knee (MOAKS) 17,18 .…”