Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA.
Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University Munich, Ismaningerstr. 22, 81675, Munich, Germany.
Abdom Radiol (NY). 2018 Feb;43(2):497-504. doi: 10.1007/s00261-017-1390-2.
The purpose of this study is to evaluate the performance of material-specific iodine (MS-I) images generated by rapid kV-switching single-source dual-energy computed tomography (rsDECT) for distinguishing post-operative changes from local tumor recurrence in patients on follow-up for pancreatic adenocarcinoma after surgical resection.
In this IRB-approved HIPPA-compliant study, retrospective review of 51 patients who underwent surgical resection of pancreatic adenocarcinoma was conducted and were followed up using contrast-enhanced rsDECT (Discovery CT 750HD, GE Healthcare, Milwaukee, WI). Independent qualitative assessment for presence of local tumor recurrence was performed by two radiologists who evaluated 65 keV (single-energy CT-equivalent interpretation) and 65 keV with MS-I (rsDECT interpretation) in separate sessions. Quantitative analysis of Hounsfield unit (HU, on 65 keV) and normalized iodine concentration (NIC on MS-I images; iodine concentration ratio in post-operative tissue to aorta) was measured. Follow-up imaging, temporal change of CEA and CA 19-9 or biopsy served as reference standard for presence and absence of local recurrence. Sensitivity and specificity of readers and quantitative parameters was calculated and receiver operating characteristic curves and Fisher's exact test were generated. A p value < 0.05 was considered statistically significant.
A total of 51 patients (27 females, 24 males) with mean age of 64 years built the final cohort. Local recurrence was absent in 23 (Group A) and present in 28 (Group B) patients. The follow-up imaging was performed within 7 months of rsDECT. For both readers, the addition of MS-I increased the specificity for tissue characterization and improved reader confidence as compared to 65 keV (specificity: 80% and 56%, respectively) images alone. Quantitative analysis revealed a significantly lower NIC (0.28 vs. 0.35; p < 0.05) for non-recurrent tissue. However, HU was not significantly different for non-recurrent and recurrent tissue (0.63 vs. 0.70; p > 0.05).
In inherently complex cases of post-operative pancreatic adenocarcinoma, MS-I images from rsDECT can be a useful adjunct to conventional scans in characterizing loco-regional soft tissue.
本研究旨在评估快速千伏切换单源双能计算机断层扫描（rsDECT）生成的特定碘（MS-I）图像在区分胰腺腺癌术后患者随访中局部肿瘤复发与术后改变方面的性能。
这项经机构审查委员会批准且符合 HIPAA 规定的研究回顾性分析了 51 例接受胰腺腺癌手术切除并接受对比增强 rsDECT（Discovery CT 750HD，GE Healthcare，密尔沃基，威斯康星州）随访的患者。两名放射科医生在单独的会议上分别对 65keV（单能量 CT 等效解释）和 65keV 与 MS-I（rsDECT 解释）进行了局部肿瘤复发存在的独立定性评估。对 65keV 上的体素（HU）和归一化碘浓度（MS-I 图像上的 NIC；术后组织与主动脉的碘浓度比）进行了定量分析。随访影像学、CEA 和 CA 19-9 的时间变化或活检作为局部复发存在和不存在的参考标准。计算了读者和定量参数的敏感性和特异性，并生成了受试者工作特征曲线和 Fisher 精确检验。p 值<0.05 被认为具有统计学意义。
最终队列由 51 名患者（27 名女性，24 名男性）组成，平均年龄为 64 岁。23 名患者（A 组）无局部复发，28 名患者（B 组）有局部复发。rsDECT 后 7 个月内进行了随访影像学检查。与仅使用 65keV 图像相比，添加 MS-I 后，两位读者的组织特征描述特异性均提高，读者信心也有所提高（特异性：分别为 80%和 56%）。定量分析显示，非复发性组织的 NIC 显著降低（0.28 比 0.35；p<0.05）。然而，非复发性和复发性组织的 HU 无显著差异（0.63 比 0.70；p>0.05）。
在胰腺腺癌术后固有复杂的情况下，rsDECT 的 MS-I 图像可以成为常规扫描的有用补充，有助于对局部软组织进行特征描述。
