Williams Ashley, Mikulis Brandon, Krishnan Nitya, Gray Martha, McKenzie Charlie, Burstein Deborah
Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA.
Magn Reson Med. 2007 Oct;58(4):830-4. doi: 10.1002/mrm.21376.
Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is based on the theory that Gd-DTPA(2-) will distribute in inverse relation to cartilage glycosaminoglycan (GAG). T(1Gd) (T(1) after penetration of a 0.2 mmol/kg dose of Gd-DTPA(2-)) has been used as the dGEMRIC index, although (1/T(1Gd)-1/T(1o)) should be more representative of Gd-DTPA(2-) concentration (where T(1o) = T(1) before contrast). T(1o) and T(1Gd) were measured in 20 volunteers at both 1.5T and 3T and the correlation between the metrics of T(1Gd) and (1/T(1Gd)-1/T(1o)) was calculated. There was a high correlation coefficient between the two metrics at both field strengths, with R = 0.94, 0.93, and 0.90 for central medial femur, posterior medial femur, and medial tibia, respectively, at 1.5T and 0.87, 0.94, 0.96 at 3T. In all cases P < 0.0001. Therefore, these data suggest that, for native cartilage, the current practice of measuring T(1Gd) (but not also T(1o)) is adequate at both 1.5T and 3T.
延迟钆增强磁共振成像（dGEMRIC）基于这样的理论，即钆喷酸葡胺（Gd-DTPA(2-)）将与软骨糖胺聚糖（GAG）呈反比分布。尽管（1/T(1Gd)-1/T(1o)）应更能代表Gd-DTPA(2-)浓度（其中T(1o)=注射造影剂前的T(1)），但T(1Gd)（注射0.2 mmol/kg剂量的Gd-DTPA(2-)后的T(1)）已被用作dGEMRIC指标。在20名志愿者中于1.5T和3T场强下测量了T(1o)和T(1Gd)，并计算了T(1Gd)指标与（1/T(1Gd)-1/T(1o)）之间的相关性。在两个场强下，这两个指标之间均有较高的相关系数，在1.5T时，股骨内侧中央、股骨内侧后部和胫骨内侧的相关系数R分别为0.94、0.93和0.90，在3T时分别为0.87、0.94和0.96。在所有情况下，P<0.0001。因此，这些数据表明，对于天然软骨，目前测量T(1Gd)（但不测量T(1o)）的做法在1.5T和3T场强下都是合适的。
