最近可用的具有Dixon技术的门控T1加权成像能够实现用于MR采集和PET重建的同步门控信号。在这里,我们评估了这种MR门控PET重建在胸腹PET/MRI中与非MR门控方法相比的临床价值。
20例患者(28个高代谢靶病灶)接受了PET/MRI检查。重建四种类型的PET图像:非MR门控衰减校正(AC)(A组),MR门控+门控AC(B组),非MR门控+屏气(BH)AC(C组),和MR门控+BHAC(D组)。提出了4分客观量表(从良好匹配到明显不匹配,从3到0评分)来评估不匹配。还评估了检出率和定量指标。
在基于患者的分析中,对于A到D组,检出率为90%,100%,85%,90%和95%,100%,85%,85%,分别由读者1和2评估,B组3分比例最高(85%,90%,35%,40%,80%,90%,35%,20%,分别由读者1和2评估)。基于病变的分析显示,A至D组的定量指标存在显着差异(所有P<0.05),B组中的定量指标最高(SUVmax:7.49±3.37、8.45±3.82、6.90±3.24和7.69±3.50;SUVmean:3.90±1.60、4.34±1.84、3.67±1.61和4.03±1.81;SUVpeak:5.60±2.50、6.10±2.80、5.22±2.40和5.65±2.68;信噪比:1.552±1.
使用门控AC的MR门控重建减少了MR和PET图像之间的不匹配,并改善了同步PET/MRI系统中的胸-腹PET图像质量。
The recently available gated T1-weighted imaging with the Dixon technique enables the synchronized gating signal for both MR acquisition and PET reconstruction. Herein, we evaluated the clinical value of this MR-gated PET reconstruction in the thoracic-abdominal PET/MRI compared with non-MR-gated method.
Twenty patients (28 hypermetabolic target lesions) underwent PET/MRI. Four types of PET images were reconstructed: non-MR-gating + gated attenuation correction (AC) (group A), MR-gating + gated AC (group B), non-MR-gating + breath-hold (BH) AC (group C), and MR-gating + BH AC (group D). A 4-point objective scale (from well match to obvious mismatch was scored from 3 to 0) was proposed to evaluate the mismatch. The detection rate and quantitative metrics were also evaluated.
In the patient-based analysis, for groups A through D, the detection rates were 90%, 100%, 85%, and 90% as well as 95%, 100%, 85%, and 85%, assessed by readers 1 and 2, respectively, and significant difference of mismatch score was observed with the highest proportion of 3 points in group B (85%, 90%, 35%, and 40%, and 80%, 90%, 35%, and 20%, assessed by readers 1 and 2, respectively). The lesion-based analysis demonstrated significant differences in quantitative metrics for groups A through D (all P\'s < 0.05), with the highest quantitative metrics in group B (SUVmax: 7.49 ± 3.37, 8.45 ± 3.82, 6.90 ± 3.24, and 7.69 ± 3.50; SUVmean: 3.90 ± 1.60, 4.34 ± 1.84, 3.67 ± 1.61, and 4.03 ± 1.81; SUVpeak: 5.60 ± 2.50, 6.10 ± 2.80, 5.22 ± 2.40, and 5.65 ± 2.68; signal-to-noise ratio: 136.06 ± 90.58, 136.24 ± 81.63, 99.52 ± 53.16, and 107.57 ± 69.05).
The MR-gated reconstruction using gated AC reduced the mismatch between MR and PET images and improved the thoracic-abdominal PET image quality in simultaneous PET/MRI systems.