Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, Via Moruzzi, 1, 56124, Pisa, Italy.
U.O.C. Bioingegneria, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy.
Radiol Med. 2022 Nov;127(11):1199-1208. doi: 10.1007/s11547-022-01554-w. Epub 2022 Sep 10.
We evaluated the feasibility and reproducibility of bone marrow T2* values and established the lower limit of normal in a cohort of healthy subjects. We investigated the clinical correlates of bone marrow T2* values in patients with thalassemia major (TM).
Thirty healthy subjects and 274 consecutive TM patients (38.96 ± 8.49 years, 151 females) underwent MRI at 1.5T. An axial slice in the upper abdomen was acquired by a T2* gradient-echo multiecho sequence and the T2* value was calculated in a circular region of interest defined in the visible body of the first or second lumbar vertebra. In patients, also liver and heart T2* values were assessed.
In healthy subjects bone marrow T2* values were independent of age and gender. The lower limit of normal for bone marrow T2* was 13 ms. In both healthy subjects and 30 randomly selected patients, the coefficient of variation for inter-operator-reproducibility was < 10%. TM patients exhibited significantly lower bone marrow T2* values than healthy subjects (7.47 ± 5.18 ms vs. 17.08 ± 1.89 ms; p < 0.0001). A pathological bone marrow T2* was detected in 82.8% of TM patients. In TM, the female sex was associated with reduced bone marrow T2* values. Bone marrow T2* values were inversely correlated with mean serum ferritin levels (R = -0.431; P < 0.0001) and hepatic iron load (R = - 0.215; P < 0.0001). A serum ferritin level > 536 ng/ml predicted the presence of a pathological bone marrow T2*. A positive correlation was found between bone marrow and heart T2* values (R = 0.143; P = 0.018). A normal bone marrow T2* showed a negative predictive value of 100% for cardiac iron.
Bone marrow T2* measurements can be easily obtained using the same sequences acquired for liver iron quantification and may bring new insights into the pathophysiology of iron deposition; hence, they should be incorporated into clinical practice.
我们评估了健康受试者骨髓 T2值的可行性和可重复性，并建立了其正常值下限。我们还研究了骨髓 T2值与地中海贫血（TM）患者临床特征的相关性。
30 名健康受试者和 274 例连续 TM 患者（38.96±8.49 岁，151 名女性）在 1.5T 磁共振仪上进行检查。采用 T2梯度回波多回波序列获取上腹部轴位图像，在可见第一或第二腰椎体的圆形感兴趣区中计算 T2值。在患者中，还评估了肝脏和心脏 T2*值。
在健康受试者中，骨髓 T2值与年龄和性别无关。骨髓 T2的正常值下限为 13ms。在健康受试者和 30 名随机选择的患者中，两名操作者间重复性的变异系数均＜10%。TM 患者的骨髓 T2值明显低于健康受试者（7.47±5.18ms vs. 17.08±1.89ms；p＜0.0001）。82.8%的 TM 患者存在病理性骨髓 T2。在 TM 中，女性患者的骨髓 T2值较低。骨髓 T2值与平均血清铁蛋白水平呈负相关（R=-0.431；P＜0.0001），与肝脏铁负荷呈负相关（R=-0.215；P＜0.0001）。血清铁蛋白水平＞536ng/ml 可预测存在病理性骨髓 T2*。骨髓 T2值与心脏 T2值呈正相关（R=0.143；P=0.018）。正常的骨髓 T2*对心脏铁具有 100%的阴性预测值。
骨髓 T2*值可通过肝脏铁定量的相同序列轻松获得，这可能为铁沉积的病理生理学提供新的见解；因此，应将其纳入临床实践。
