Value of a Dixon-based MR/PET attenuation correction sequence for the localization and evaluation of PET-positive lesions
Value of a Dixon-based MR/PET attenuation correction sequence for the localization and evaluation of PET-positive lesions
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DOI：
10.1007/s00259-011-1842-9
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发表时间：
2011-09-01
影响因子：
9.1
通讯作者：
Beer, Ambros J.
中科院分区：
文献类型：
--
作者：
Eiber, Matthias;Martinez-Moeller, Axel;Beer, Ambros J.
目的在本研究中，评价了Dixon MR成像与快速低分辨率屏气序列（用于MR/正电子发射断层扫描（PET）的MR衰减校正（AC）的技术）的潜在贡献，以比较3 T临床扫描仪与低剂量CT上PET阳性病变的解剖相关性。这种技术也用于最近安装的完全集成的全身MR/PET system.Methods 35例患者常规安排肿瘤分期进行F-18-氟脱氧葡萄糖（FDG）PET/CT和2点狄克逊3-D容积内插屏气检查（VIBE）T1加权MR序列在同一天。评价了使用低剂量CT（PETAC_CT）或模拟MR分割（PETAC_MR）的衰减图重建的两个PET数据集的局灶性PET阳性病变。在低剂量CT和基于Dixon的MRI中以4分量表（0-3）判断与解剖结构相关性的确定性。此外，PETAC_CT和PETAC_MR的标准化摄取值（SUV）进行了compared.Results统计学上，没有显着差异，可以发现关于解剖定位的所有81 PET阳性病变在低剂量CT相比，基于Dixon的MR（平均值分别为2.51 +/- 0.85和2.37 +/- 0.87，p = 0.1909）。CT往往是上级的小淋巴结，骨转移和肺结节，而基于Dixon的MR被证明有利于软组织病变，如头部/颈部肿瘤和肝转移。对于基于PETAC_CT和PETAC_MR的SUV（平均值分别为6.36 +/- 4.47和6.31 +/- 4.52），发现几乎完全一致，具有高度显著相关性结论基于Dixon的MR AC成像与常规PET/CT的低剂量CT成像相似，能够对PET阳性病灶进行解剖定位。因此，这种方法似乎是有用的，未来的MR/PET的身体区域没有完全覆盖的诊断MRI由于潜在的时间限制。
Purpose In this study, the potential contribution of Dixon-based MR imaging with a rapid low-resolution breath-hold sequence, which is a technique used for MR-based attenuation correction (AC) for MR/positron emission tomography (PET), was evaluated for anatomical correlation of PET-positive lesions on a 3T clinical scanner compared to low-dose CT. This technique is also used in a recently installed fully integrated whole-body MR/PET system.Methods Thirty-five patients routinely scheduled for oncological staging underwent F-18-fluorodeoxyglucose (FDG) PET/CT and a 2-point Dixon 3-D volumetric interpolated breath-hold examination (VIBE) T1-weighted MR sequence on the same day. Two PET data sets reconstructed using attenuation maps from low-dose CT (PETAC_CT) or simulated MR-based segmentation (PETAC_MR) were evaluated for focal PET-positive lesions. The certainty for the correlation with anatomical structures was judged in the low-dose CT and Dixon-based MRI on a 4-point scale (0-3). In addition, the standardized uptake values (SUVs) for PETAC_CT and PETAC_MR were compared.Results Statistically, no significant difference could be found concerning anatomical localization for all 81 PET-positive lesions in low-dose CT compared to Dixon-based MR (mean 2.51 +/- 0.85 and 2.37 +/- 0.87, respectively; p = 0.1909). CT tended to be superior for small lymph nodes, bone metastases and pulmonary nodules, while Dixon-based MR proved advantageous for soft tissue pathologies like head/neck tumours and liver metastases. For the PETAC_CT- and PETAC_MR-based SUVs (mean 6.36 +/- 4.47 and 6.31 +/- 4.52, respectively) a nearly complete concordance with a highly significant correlation was found (r = 0.9975, p < 0.0001).Conclusion Dixon-based MR imaging for MR AC allows for anatomical allocation of PET-positive lesions similar to low-dose CT in conventional PET/CT. Thus, this approach appears to be useful for future MR/PET for body regions not fully covered by diagnostic MRI due to potential time constraints.