Comparative reliability and diagnostic performance of conventional 3T magnetic resonance imaging and 1.5T magnetic resonance arthrography for the evaluation of internal derangement of the hip

Abstract

ObjectiveTo compare the diagnostic accuracy of conventional 3T MRI against 1.5T MR arthrography (MRA) in patients with clinical femoroacetabular impingement (FAI).MethodsSixty-eight consecutive patients with clinical FAI underwent both 1.5T MRA and 3T MRI. Imaging was prospectively analysed by two musculoskeletal radiologists, blinded to patient outcomes and scored for internal derangement including labral and cartilage abnormality. Interobserver variation was assessed by kappa analysis. Thirty-nine patients subsequently underwent hip arthroscopy and surgical results and radiology findings were analysed.ResultsBoth readers had higher sensitivities for detecting labral tears with 3T MRI compared to 1.5T MRA (not statistically significant p=0.07). For acetabular cartilage defect both readers had higher statistically significant sensitivities using 3T MRI compared to 1.5T MRA (p=0.02). Both readers had a slightly higher sensitivity for detecting delamination with 1.5T MRA compared to 3T MRI, but these differences were not statistically significant (p=0.66). Interobserver agreement was substantial to perfect agreement for all parameters except the identification of delamination (3T MRI showed moderate agreement and 1.5T MRA substantial agreement).ConclusionConventional 3T MRI may be at least equivalent to 1.5T MRA in detecting acetabular labrum and possibly superior to 1.5T MRA in detecting cartilage defects in patients with suspected FAI.Key Points• Conventional 3T MRI is equivalent to 1.5T MRA for diagnosing labral tears. • Conventional 3T MRI is superior to 1.5T MRA for diagnosing acetabular cartilage defect. • Conventional 3T MRI is equivalent to 1.5T MRA for diagnosing cartilage delamination. • Symptom severity score was significantly higher (p<0.05) in group proceeding to surgery.

Validation of scoring hip osteoarthritis with MRI (SHOMRI) scores using hip arthroscopy as a standard of reference

“…However, although several studies have reported a higher accuracy for MR arthrography in the detection of chondrolabral lesions [17,30,31], the use of intraarticular contrast might not be logistically feasible in a larger study trial and/or in clinical [32], and, more importantly, for the majority of these studies, a 1.5-T MRI system was used. In this context, recent studies have shown that the use of a high-resolution, nonarthrographic 3-T MRI is capable of detecting chondral and labral abnormalities with high accuracy [20,33,34] and therefore may obviate the need for intraarticular contrast. One of the primary characteristics of our study design was the feasibility of SHOMRI to detect cartilage lesions with surgical reports as the standard of reference.…”

Conventional and Arthrographic Magnetic Resonance Techniques for Hip Evaluation: What the Radiologist Should Know

“…Contrast extending into the labrum or its base facilitates the diagnosis of labrum tears, and contrast accumulation between the femoroacetabular interface indicates cartilage thinning or defects. Encouraging results of two recent studies suggested that due to its higher SNR, noncontrast MRI at 3 T could replace direct MR arthrography at 1.5 T. 108,109 In contrast, a higher diagnostic performance was reported for direct MR arthrography at 1.5 and 3 T in other studies. [110][111][112] In light of these conflicting reports, it is important to highlight that extensive cartilage damage (> 2 hours on the clock face, i.e., extending over 60 degrees on the radial plane) was identified as the strongest risk factor for long-term failure of FAI correction based on preoperative direct MR arthrography at 1.5 T that supports its prognostic value.…”

Hip preservation

“… 5 , 6 Although promising results have been demonstrated for non-contrast MRI of the hip at 3 T, direct MR arthrography is still the current diagnostic gold-standard in the detection of chondrolabral lesions. 7 – 9 MR arthrograms provide crucial prognostic information as extensive cartilage defects, acetabular cysts and osteophyte formations indicate a higher risk for failure of femoro-acetabular impingement (FAI) surgery in the long-term. 10 Injection of intra-articular contrast agent further enables application of leg traction to achieve joint distraction and has shown promising early results to improve the visualization of intra-articular lesions.…”