T2 mapping of the acetabular cartilage in infants and children with developmental dysplasia of the hip

Abstract

Background T2 mapping is useful for evaluating the cartilage matrix. Purpose To determine the variations in the acetabular cartilage T2 relaxation values between healthy individuals and those with developmental dysplasia of the hip (DDH). Material and Methods Thirty-three patients with unilateral DDH underwent 3-T magnetic resonance imaging (MRI) between January 2018 and February 2019. Fifteen volunteers (30 hips) were enrolled as controls. T2 values were measured with the T2 mapping sequence in all layers and were equally divided into three layers (deep, middle, and superficial) with equal thickness. We calculated the mean T2 relaxation values for the full thickness, deep, middle, and superficial layers and compared the values between the different groups. In addition, the inter- and intra-observer agreements were calculated. Results The T2 relaxation values in the DDH arm were significantly lower in the middle, superficial, and full thickness layers compared with those of the volunteers and contralateral hips. The T2 relaxation values of the deep layers showed no significant difference between the different groups. The acetabular cartilage T2 relaxation values increased from the deep layer to the superficial layer in the control and contralateral groups. Both inter- and intra-observer agreements were good. Conclusion MRI T2 mapping may help to diagnose developmental disorders of the acetabular cartilage matrix in infants and children with DDH. Abnormal acetabular cartilage T2 relaxation values may be due to the extraordinary stress load of the femoral head.

T2 Mapping of Patellar Cartilage After a Single First‐Time Episode of Traumatic Lateral Patellar Dislocation

“…The finding that T 2 in healthy cartilage goes up from the deep to the superficial layer is consistent with results of many studies 25 . The T 2 relaxation time is influenced both by the organization of the extracellular matrix (collagen fiber orientation) 26 and by the water content of native articular cartilage 27 .…”

“…The finding that T 2 in healthy cartilage goes up from the deep to the superficial layer is consistent with results of many studies. 25 The T 2 relaxation time is influenced both by the organization of the extracellular matrix (collagen fiber orientation) 26 and by the water content of native articular cartilage. 27 In the radial zone, near the cartilage-bone interface, fibrils are perpendicular to the cortical surface; toward the articular surface, in the transitional zone, the fibers have random orientations, whereas in the superficial zone, the collagen fibers are oriented parallel to the surface.…”

T2 Relaxation Time Changes in the Distal Femoral Condylar Cartilage of Children and Young Adults with Discoid Meniscus

“…These researchers found that bulk T2 averaging masks important local variations. In pediatric hips, Lu et al 33 evaluated acetabular cartilage using all layers and 3 layers equally divided. The acetabular cartilage T2 relaxation values increased from the deep layer to the superficial layer in healthy hips.…”

A short-term magnetic resonance imaging analysis of acetabular adaptation in developmental dysplasia of the hip by open reduction or open reduction combined with Dega osteotomy

“…MRI with good tissue resolution has been used to assess the immature hip joint cartilage and osseous acetabulum anatomy. [4] Early DDH lesions are located on the acetabular side. Changes to the femur in older children are secondary to the pressure the acetabulum or iliac bone exerts on the femoral head.…”

“…MRI with good tissue resolution has been used to assess the immature hip joint cartilage and osseous acetabulum anatomy [4] . Early DDH lesions are located on the acetabular side.…”