KURODA Kagayaki Tokai University, Department of Human and Information Science, Associate Professor, 電子情報学部, 助教授 (70205243)
SUGANO Nobuhiko Osaka University, Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (70273620)
MIKI Hidenobu National Hospital Organization Osaka National Hospital, Institute for Clinical Research, Doctor, 臨床研究部, 医師 (10335391)
田中 正夫 大阪大学, 基礎工学研究科, 教授 (40163571)
|Budget Amount *help
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2004: ¥1,900,000 (Direct Cost: ¥1,900,000)
To investigate reliable imaging technology with less invasiveness for patients with joint disorder, such as osteoarthritis, we conducted following basic experiments and clinical investigations.
(1) New radio-frequency (RF) coils, which are applicable to 3-T MR imaging, were developed for hip and knee joint. Ability of signal acquisition, signal uniformity, and safety were investigated.
(2) Computer programs specific to assessment of hip and knee cartilage on MR images were developed. Using the programs, thickness and MR parameters (T2 values) of cartilage matrix were calculated at various sites, with high reproducibility.
(3) Using resected human cartilage-bone specimen from patients with fracture of the femoral head, correlation of MR parameters of cartilage and cartilage matrix quantity such as proteoglycan, collagen and water, were evaluated. Among those matrixes, collagen content was highly associated with MR T2 values.
(4) The feasibility of T2 assessment using magnetic resonance imag
ing at 3T was assessed for evaluating early changes in the acetabular and femoral cartilages for patients with hip dysplasia. Sagittal T2 maps of the hip were obtained using 3T MR imaging in 9 normal volunteers (9 hips) and in 14 patients (15 hips) with hip dysplasia at pre-or early-arthritic stages. T2 values and the visual appearance of T2 mapping, including gradient T2,low T2,and high T2 patterns, were compared at the superior zones of the acetabular and femoral cartilages among the normal, pre-arthritic, and early-arthritic groups. T2 mapping classification enabled the early detection of osteoarthritic degeneration and the detection of developmental disorders of cartilage matrix in patients with hip dysplasia.
(5) Clinical feasibility of MR imaging with a mechanical loading system for evaluation of load-bearing function in knee joints was prospectively assessed, using cartilage T2 as a surrogate of cartilage matrix changes. Sagittal T2 maps of the medial and lateral femoro-tibial joints of 22 healthy volunteers (nine men, 13 women; mean age, 25 years) were obtained using 3.0 T MR imaging. Under loading conditions, an axial compression force of 50% of body weight was applied during MR imaging. T2 values of the femoral and tibial cartilage at the weight-bearing area were compared between loading and unloading conditions. The clinical feasibility of MR imaging with mechanical loading was demonstrated to detect site-specific changes in cartilage T2 during loading. From responsiveness of loading, T2 evaluation may allow sensitive detection of early degenerative changes in the cartilage and meniscus, by revealing pathological conditions related to localized stress concentration in the cartilage. Less