Conspicuity of FDG-Avid Osseous Lesions on PET/MRI Versus PET/CT: a Quantitative and Visual Analysis.
Conspicuity of FDG-Avid Osseous Lesions on PET/MRI Versus PET/CT: a Quantitative and Visual Analysis.
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PET/MRI 与 PET/CT 上 FDG-Avid 骨病变的明显性：定量和视觉分析。
DOI：
10.1007/s13139-016-0403-3
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发表时间：
2016
影响因子：
1.3
通讯作者：
McConathy,Jonathan
中科院分区：
文献类型：
--
作者：
Fraum,TylerJ;Fowler,KathrynJ;McConathy,Jonathan
由于标准MRI衰减校正（AC）不能解释皮质骨对光子的衰减，PET/MRI对FDG敏感的局灶性骨病变（FFBL）的敏感性可能降低。这项研究评估是否基于MRI的AC妥协检测FFBLs，通过比较他们的显着性定量和定性的PET/MRI与PET/CT.Methods190例普通肿瘤患者进行了全身PET/CT，其次是全身PET/MRI，利用相同的FDG剂量。确定了13例患者，共50例FFBL。使用自动轮廓绘制软件，为每个FFBL生成体积轮廓。手动选择正常背景骨（BB）的相邻区域。对于每个轮廓，确定SUV最大值和SUV平均值。病变与背景SUV的比率作为显著性的定量指标。此外，两名设盲阅片人评价了基于MRI的AC与基于CT的AC的PET图像上FFBL的相对显著性。在相应的CT和MR images. ResultsSUV的解剖学相关的FFBLs的可见性也是较低的PET/MRI FFBLs（-6.5%，p= 0.009）和BB（-20.5%，p< 0.001）。PET/MRI上BB（-14.2%，p= 0.002）的SUV最大值较低，但FFBL（-6.2%，p= 0.068）的SUV最大值不低。PET/MRI的FFBL SUV平均值与BB SUV平均值的比值较高（+29.5%，p< 0.001）。50处病变中的40处（80%）在PET/MRI的PET图像上被视为具有同等或更高的明显性。50个FFBL中的35个（70%）具有CT相关性，而50个FFBL中的40个（80%）在至少一个MRI序列上具有相关性。PET/MRI从示踪剂给药到成像的平均间隔较长（p< 0.001）（127 v.62 min）。这一发现可能部分归因于基于MRI的AC与基于CT的AC在处理皮质骨方面的差异。尽管存在这种系统性偏倚，但FFBL在PET/MRI上的定性和定量均更显著。这种差异可能是由于PET/MRI的示踪剂摄取时间较长，这使得FFBL的示踪剂蓄积更多，BB的示踪剂洗脱更多。我们的研究结果表明，全身PET/MRI和PET/CT提供了相当的灵敏度检测FDG-亲局灶性骨病变。
BackgroundBecause standard MRI-based attenuation correction (AC) does not account for the attenuation of photons by cortical bone, PET/MRI may have reduced sensitivity for FDG-avid focal bone lesions (FFBLs). This study evaluates whether MRI-based AC compromises detection of FFBLs, by comparing their conspicuity both quantitatively and qualitatively on PET/MRI versus PET/CT.MethodsOne hundred ninety general oncology patients underwent whole-body PET/CT followed by whole-body PET/MRI, utilizing the same FDG dose. Thirteen patients with a total of 50 FFBLs were identified. Using automated contouring software, a volumetric contour was generated for each FFBL. Adjacent regions of normal background bone (BB) were selected manually. For each contour, SUV-max and SUV-mean were determined. Lesion-to-background SUV ratios served as quantitative metrics of conspicuity. Additionally, two blinded readers evaluated the relative conspicuity of FFBLs on PET images derived from MRI-based AC versus CT-based AC. Visibility of an anatomic correlate for FFBLs on the corresponding CT and MR images was also assessed.ResultsSUV-mean was lower on PET/MRI for both FFBLs (-6.5 %,p= 0.009) and BB (-20.5 %,p< 0.001). SUV-max was lower on PET/MRI for BB (-14.2 %,p= 0.002) but not for FFBLs (-6.2 %,p= 0.068). The ratio of FFBL SUV-mean to BB SUV-mean was higher for PET/MRI (+29.5 %,p< 0.001). Forty of 50 lesions (80 %) were visually deemed to be of equal or greater conspicuity on PET images derived from PET/MRI. Thirty-five of 50 FFBLs (70 %) had CT correlates, while 40/50 FFBLs (80 %) had a correlate on at least one MRI sequence. The mean interval from tracer administration to imaging was longer (p< 0.001) for PET/MRI (127 v. 62 min).ConclusionsBoth FFBLs and BB had lower mean SUVs on PET/MRI than PET/CT. This finding was likely in part due to differences in the handling of cortical bone by MRI-based AC versus CT-based AC. Despite this systematic bias, FFBLs had greater conspicuity on PET/MRI, both qualitatively and quantitatively. This difference was likely due to the longer tracer uptake times for PET/MRI, which allowed for more tracer accumulation by FFBLs and more tracer washout from BB. Our results suggest that whole-body PET/MRI and PET/CT provide comparable sensitivity for detection of FDG-avid focal bone lesions.