Dardzinski Bernard J, Laor Tal, Schmithorst Vincent J, Klosterman Lance, Graham T Brent
Department of Pediatrics, Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA.
Radiology. 2002 Oct;225(1):233-9. doi: 10.1148/radiol.2251011461.
To determine the feasibility of mapping the spatial variation of cartilage T2 relaxation time in vivo in the pediatric knee with a 1.5-T clinical magnetic resonance (MR) imaging system and the manufacturer's body gradient coil.
Twenty-five children and adolescents (age range, 5-17 years; mean age, 11.8 years) underwent a multisection-multiecho MR sequence for T2 relaxation time mapping. Quantitative transverse T2 maps of the patellar cartilage were calculated for 15 of the subjects. Sagittal T2 maps were calculated for the remaining 10 subjects. T2 profiles were generated for the patellar and distal femoral weight- and non-weight-bearing unossified epiphyseal and articular hyaline cartilage and for the distal femoral and proximal tibial physes. The Mann-Whitney U test was used to test for differences between paired profiles.
Femoral non-weight-bearing unossified epiphyseal and articular cartilage showed spatial variation similar to that of weight-bearing unossified epiphyseal and articular cartilage, but with increased T2 values (P <.001). T2 spatial variations of the distal femoral and proximal tibial physes were similar to those of epiphyseal and articular cartilage but had a different pattern and increased magnitude (P <.001). The highest T2 values were measured in the distal femoral physis.
T2 spatial variation of patellar hyaline cartilage in children is similar to that of patellar articular cartilage in adults. Mapping of spatial variation of T2 relaxation time of cartilage in the pediatric knee in vivo is feasible with a clinical 1.5-T MR imaging system and a body gradient coil.
利用1.5-T临床磁共振（MR）成像系统及制造商的体梯度线圈，确定在体测绘小儿膝关节软骨T2弛豫时间空间变化的可行性。
25名儿童及青少年（年龄范围5至17岁；平均年龄11.8岁）接受了用于T2弛豫时间测绘的多层面多回波MR序列检查。为15名受试者计算了髌软骨的定量横向T2图。为其余10名受试者计算了矢状面T2图。生成了髌股和股骨远端负重及非负重未骨化骨骺和关节透明软骨以及股骨远端和胫骨近端生长板的T2剖面图。采用曼-惠特尼U检验来检测配对剖面图之间的差异。
股骨非负重未骨化骨骺和关节软骨显示出与负重未骨化骨骺和关节软骨相似的空间变化，但T2值升高（P<.001）。股骨远端和胫骨近端生长板的T2空间变化与骨骺和关节软骨相似，但模式不同且幅度增大（P<.001）。在股骨远端生长板测得的T2值最高。
儿童髌透明软骨的T2空间变化与成人髌关节软骨相似。利用临床1.5-T MR成像系统和体梯度线圈在体测绘小儿膝关节软骨T2弛豫时间的空间变化是可行的。
