Department of Radiology, The Royal Marsden NHS Foundation Trust, Sutton, UK.
Br J Radiol. 2012 Dec;85(1020):e1198-203. doi: 10.1259/bjr/52759767.
To measure apparent diffusion coefficient (ADC) values in patients with active myeloma and remission and to determine whether changes differ in those responding/progressing on treatment. The relationship between changes in marrow fat and ADC was also explored.
20 patients were recruited. T(1 )weighted, T(2) weighted, short tau inversion-recovery, diffusion-weighted and two-point Dixon MRI of the lumbar spine and pelvis were performed at baseline, 4-6 weeks and 20 weeks.
ADC values of active disease (mean 761.2 ± 255×10(-6) mm(2) s(-1)) were significantly higher (p=0.047) than marrow in remission (mean 601.8 ± 459×10(-6) mm(2) s(-1)). Changes in ADC in responders showed a significant increase at 4-6 weeks (p=0.005) but no significant change between baseline and 20 weeks (p=0.733). ADCs in progressing and stable patients did not change significantly between either time point. Pearson's correlation coefficient between change in fat fraction and change in the number of pixels with an ADC of ≤655×10(-6) mm(2) s(-1) was 0.924, indicating a significant correlation (p<0.001).
ADC values in active myeloma are significantly higher than marrow in remission, indicating the potential for diffusion-weighted MRI to quantify the transition from active disease to remission and vice versa. This study confirms significant changes in ADC in patients responding to treatment and indirect evidence from two-point Dixon MRI suggests that these changes are influenced by changes in marrow fat.
ADC of active myeloma is significantly higher than marrow in remission; the direction of ADC changes on treatment is dependent on the timing of measurements and is influenced by changes in marrow fat.
测量活动期骨髓瘤和缓解期骨髓瘤患者的表观扩散系数（ADC）值，并确定治疗中反应/进展患者的 ADC 值变化是否不同。还探讨了骨髓脂肪与 ADC 变化之间的关系。
共招募了 20 名患者。基线时、4-6 周和 20 周时，对患者的腰椎和骨盆进行 T1 加权、T2 加权、短回波反转恢复、弥散加权和两点 Dixon MRI 检查。
活动期疾病的 ADC 值（平均值 761.2±255×10(-6)mm(2)s(-1)）明显高于缓解期骨髓（平均值 601.8±459×10(-6)mm(2)s(-1)）（p=0.047）。反应者的 ADC 值在 4-6 周时显著增加（p=0.005），但在基线和 20 周时无明显变化（p=0.733）。进展和稳定患者的 ADC 值在任何时间点均无明显变化。脂肪分数变化与 ADC 值≤655×10(-6)mm(2)s(-1)的像素数变化之间的 Pearson 相关系数为 0.924，表明相关性显著（p<0.001）。
活动期骨髓瘤的 ADC 值明显高于缓解期骨髓，这表明弥散加权 MRI 有可能定量测量从活动期疾病向缓解期疾病的转变，反之亦然。本研究证实，对治疗有反应的患者的 ADC 值有明显变化，两点 Dixon MRI 的间接证据表明，这些变化受骨髓脂肪变化的影响。
活动期骨髓瘤的 ADC 值明显高于缓解期骨髓；治疗时 ADC 变化的方向取决于测量时间，并且受骨髓脂肪变化的影响。
