Cartilage T1ρ and T2 Relaxation Times in Patients With Mild‐to‐Moderate Radiographic Hip Osteoarthritis

Abstract

Objective. To analyze region-specific T1r and T2 relaxation times of the hip joint cartilage in relation to presence or absence of radiographic hip osteoarthritis (OA) and presence or absence of magnetic resonance imaging (MRI)-detected cartilage defects.Methods. Weight-bearing radiographs and 3T MRI studies of the hip were obtained from 84 volunteers. Based on Kellgren/Lawrence (K/L) scoring of the radiographs, 54 subjects were classified as healthy controls (K/L grade £1) and 30 were classified as having mild or moderate radiographic hip OA (K/L grades 2 or 3, respectively). Two-dimensional fat-suppressed fast spin-echo MRI sequences were used for semiquantitative clinical scoring of cartilage defects, and a T1r/T2 sequence was used to quantitatively assess the cartilage matrix. The femoral and acetabular cartilage was then segmented into 8 regions and the mean T1r/T2 values were calculated. Differences in T1r and T2 relaxation times were compared between subjects with and those without radiographic hip OA, and those with and those without femoral or acetabular cartilage defects.Results. Higher T1r and T2 relaxation times in the anterior superior and central regions of the acetabular cartilage were seen in individuals with radiographic hip OA and those with acetabular cartilage defects compared to their respective controls (P < 0.05). In the femoral cartilage, the differences in T1r and T2 were not significant for any of the comparisons. Significant differences in the T1r and T2 values (each P < 0.05) were found in more subregions of the cartilage and across the whole cartilage when subjects were stratified based on the presence of MRI-detected cartilage defects than when they were stratified based on the presence of radiographic hip OA.Conclusion. T1r and T2 relaxation parameters are sensitive to the presence of cartilage degeneration. Both parameters may therefore support MRI evidence of cartilage defects of the hip.One in 4 individuals has a lifetime risk of developing symptomatic hip osteoarthritis (OA) by the age of 85 years (1). Individuals with hip OA experience substantial pain and disability, suggesting an urgent clinical need for diagnosis and prevention of hip OA (2,3). Hip OA is typically diagnosed through the use of radiographs, and semiquantitative clinical scores, such as the Kellgren/Lawrence (K/L) scores for radiographic damage (4), are used to quantify the severity of OA. However, diagnosis of OA with the use of radiographs is mostly focused on osteophytes and joint space narrowing, features that are indicative of advanced disease, whereas radiography lacks sensitivity for early changes of the soft tissues, such as cartilage and labrum. Magnetic resonance imaging (MRI) can provide information on hip degeneration at an earlier stage, by allowing visualization of morphologic abnormalities of the cartilage, bone marrow, and labrum (5-8).Early changes in OA consist of proteoglycan loss, changes in water content, and collagen disruption (9).

T1ρ and T2 relaxation times are associated with progression of hip osteoarthritis

“…Progression of hip OA, defined as new or increased severity of cartilage lesions between baseline and 18 months, was assessed using an MR-based semiquantitative scoring system (SHOMRI). In contrast to radiographs, which have been used in previous studies to define OA severity and progression, SHOMRI can reliably identify subtle morphologic changes associated with hip OA 7,10,34,35 . This sensitivity is shown reflected by the difference in SHOMRI cartilage scores between progressors and non-progressors.…”

“…At follow-up, the hip scanned at baseline was re-scanned for each subject. The MRI protocol included intermediate-weighted fat-suppressed fast spin-echo (FSE) sequences in sagittal, oblique coronal, and oblique axial orientations, following the protocol described by Wyatt et al 10 . These sequences were used for semi-quantitative clinical grading of OA-related abnormalities.…”

“…Previous studies in the hip have used T 1ρ and T 2 quantification to assess compositional changes in cartilage associated with hip OA, hip dysplasia and femoroacetabular impingement (FAI) 10–12 . However, these studies have only focused on a cross-sectional analysis of these populations, and it is unclear whether these measurements are associated with longitudinal progression of degenerative changes in the hip.…”

Osteoarthritis year in review 2015: imaging

“…Another study showed that ultrasound detected inflammatory features, including synovial thickening, effusion and power Doppler signal, especially when persistently 3 Radiography Hip and pelvic geometry are associated with the risk of compartment-specific knee OA Thomas GE, et al 49 Radiography Cam-type FAI and acetabular dysplasia predict development of hip OA and joint replacement High bone mineral density is associated with knee and hip OA Hardcastle SA, et al 4e6 Radiography High BMD Z scores are associated with increased prevalence of hip and knee OA, specifically osteophytosis Potential new approaches to examining joint structures Turunen M, et al 7 CT CBCT can measure volumetric BMD of cortical, trabecular, and subchondral trabecular bone Kokkonen HT, et al 8 CT Arthrographic images enables sensitive detection of cartilage lesions Riecke BF, et al 10 US Ultrasound score is reliable and valid in detecting knee OA Abraham AM, et al 14 US US demonstrates higher prevalence of osteophytes in hand and hip OA than radiographic studies Liukkonen J, et al 15 US Arthroscopic ultrasound imaging quantitatively evaluates articular cartilage Hirata Y, et al 16 Kobayashi N, et al 17 PET 18F-fluoride uptake is associated with mechanical stress in hip OA and can detect bone abnormalities earlier than MRI Ultrasonographic abnormalities correlate with clinical endpoints Hall M, et al 11 US Effusion and synovial hypertrophy are more common in knee OA, with severity correlating with radiographic severity of knee OA Birn J, et al 12 US Large joint effusions correlates with rapidly destructive hip OA Malas FU, et al 13 US Meniscal bulging is associated with radiographic joint space narrowing and KL grades What is new in magnetic resonance imaging? Morphological structural abnormalities predict clinical endpoints Sharma L, et al 19 MRI Cartilage damage, BMLs, meniscal tears, and meniscal extrusion are associated with prevalent frequent knee symptoms and/or incident persistent symptoms Roemer FW, et al 21 MRI Cartilage damage, BMLs, meniscal damage, synovitis and effusion predicted short-term need for knee joint replacement Eckstein F, et al 22 MRI Accelerated cartilage thickness loss is greatest closest to the time of knee replacement Composition of cartilage influences morphometry Crema MD, et al 25 MRI Poorer dermis endpoints are associated with increased cartilage thickness, potentially representing "cartilage swelling" Ukiah T, et al 26 MRI Diffusion tensor imaging can distinguish early cartilage damage Wyatt C, et al 28 MRI T1r and T2 relaxation times of hip cartilage are associated with cartilage defects and radiographic hip OA Crema MD, et al 29…”

Quantitative assessment of morphology, T1ρ, and T2 of shoulder cartilage using MRI

“…However, most of these studies have been performed at the knee joint, which is the joint with thickest cartilage in the appendicular skeleton [1–8]. Furthermore, T 1ρ and T 2 relaxation has been recently used to assess biochemical composition of cartilage in the knee [9; 10] and hip [11; 12] and potentially detect cartilage at risk of developing OA before the irreversible changes of OA occur in the morphological images [13; 14]. …”