Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Division of Biostatistics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Br J Radiol. 2023 Apr 1;96(1145):20220745. doi: 10.1259/bjr.20220745. Epub 2023 Apr 12.
To investigate the reproducibility of size measurements of focal bone marrow lesions (FL) in MRI in patients with monoclonal plasma cell disorders under variation of patient positioning and observer.
A data set from a prospective test-retest study was used, in which 37 patients with a total of 140 FL had undergone 2 MRI scans with identical parameters after patient repositioning. Two readers measured long and short axis diameter on the initial scan in weighted, weighted short tau inversion recovery and diffusion-weighted imaging sequences. The first reader additionally measured FL on the retest-scan. The Bland-Altman method was used to assess limits of agreement (LoA), and the frequencies of absolute size changes were calculated.
In the simple test-retest experiment with one identical reader, a deviation of ≥1 mm / ≥2 mm / ≥3 mm for the long axis diameter in weighted images was observed in 66% / 25% / 8% of cases. When comparing measurements of one reader on the first scan to the measurement of the other reader on the retest scan, a change of ≥1 mm / ≥3 mm / ≥5 mm for the long axis diameter in weighted images was observed in 78% / 21% / 5% of cases.
Small deviations in FL size are common and probably due to variation in patient positioning or inter-rater variability alone, without any actual biological change of the FL. Knowledge of the uncertainty associated with size measurements of FLs is critical for radiologists and oncologists when interpreting changes in FL size in clinical practice and in clinical trials.
According to the MY-RADs criteria, size measurements of focal lesions in MRI are now of relevance for response assessment in patients with monoclonal plasma cell disorders.Size changes of 1 or 2 mm are frequently observed due to uncertainty of the measurement only, while the actual focal lesion has not undergone any biological change.Size changes of at least 6 mm or more in weighted or weighted short tau inversion recovery sequences occur in only 5% or less of cases when the focal lesion has not undergone any biological change.
研究在患者体位和观察者变化的情况下，磁共振成像（MRI）中单克隆浆细胞疾病患者局灶性骨髓病变（FL）大小测量的重复性。
使用前瞻性测试-再测试研究的数据，37 例多发性骨髓瘤患者共 140 个 FL 进行了 2 次 MRI 扫描，在患者重新定位后使用相同的参数。两位读者分别在初始扫描的 T1WI、T2WI 短 tau 反转恢复序列和弥散加权成像序列中测量长轴和短轴直径。第一位读者还在复测扫描中测量了 FL。使用 Bland-Altman 方法评估了一致性界限（LoA），并计算了绝对尺寸变化的频率。
在一位相同读者的简单测试-再测试实验中，66%的情况下 T1WI 长轴直径的偏差为≥1mm/≥2mm/≥3mm，25%的情况下 T1WI 长轴直径的偏差为≥1mm/≥3mm/≥5mm。当比较一位读者在首次扫描的测量值与另一位读者在复测扫描的测量值时，78%的情况下 T1WI 长轴直径的偏差为≥1mm/≥3mm/≥5mm，21%的情况下 T1WI 长轴直径的偏差为≥1mm/≥3mm/≥5mm。
FL 大小的微小偏差很常见，可能仅由于患者体位的变化或观察者之间的差异所致，而不是 FL 的实际生物学变化。当在临床实践和临床试验中解释 FL 大小的变化时，了解与 FL 大小测量相关的不确定性对放射科医生和肿瘤学家至关重要。
根据 MY-RADs 标准，MRI 中局灶性病变的大小测量现在与单克隆浆细胞疾病患者的反应评估相关。由于测量的不确定性，经常观察到 1 或 2mm 的大小变化，而实际的局灶性病变并没有发生任何生物学变化。在没有发生任何生物学变化的情况下，仅在 5%或更少的情况下，在 T1WI 或 T2WI 短 tau 反转恢复序列中观察到至少 6mm 或更大的大小变化。
