Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Qiaokou District, Wuhan 430030, China.
Department of Radiology, Johns Hopkins Hospital, Johns Hopkins University, Baltimore, MD.
AJR Am J Roentgenol. 2020 Feb;214(2):383-389. doi: 10.2214/AJR.19.21668. Epub 2019 Oct 31.
The objective of our study was to compare the feasibility of R2* and apparent diffusion coefficient (ADC) for differentiating tumor grade and T category of bladder cancer. In this prospective study, 58 patients with pathologically confirmed bladder cancers underwent pretreatment T2*-weighted imaging and DWI on a 3-T MRI unit. The apparent transverse relaxation rate R2*, which is derived from T2*-weighted imaging, and ADC, which is derived from DWI, were calculated and compared between low- and high-grade bladder cancers as well as between non-muscle-invasive bladder cancers (NMIBCs) and muscle-invasive bladder cancers (MIBCs) using the Mann-Whitney test. The diagnostic performances of R2*, ADC, and the combination of R2* and ADC were evaluated through an ROC analysis. Significant differences were found in R2* (mean ± SD, 16.55 ± 5.54 vs 20.96 ± 7.75 s; = 0.001) and ADC (1.62 ± 0.31 vs 1.33 ± 0.21 × 10 mm/s; < 0.001) between lowand high-grade bladder cancers. R2* was significantly higher (22.56 ± 8.41 vs 18.06 ± 6.46 s; 0.008) and ADC was considerably lower (1.21 ± 0.18 vs 1.53 ± 0.27 × 10 mm/s; < 0.001) in MIBCs than in NMIBCs. The AUCs for differentiating low-from high-grade groups were 0.714 using R2* and 0.779 using ADC. AUCs for distinguishing between NMIBC and MIBC groups using R2* and ADC were 0.682 and 0.850, respectively. In addition to ADC, R2* can be used as a quantitative imaging biomarker to provide additional information for tumor characterization of bladder cancer.
我们的研究目的是比较 R2* 和表观扩散系数（ADC）在鉴别膀胱癌肿瘤分级和 T 分期方面的可行性。在这项前瞻性研究中，58 例经病理证实的膀胱癌患者在 3T MRI 单元上进行了预处理 T2*-加权成像和 DWI。从 T2*-加权成像中得出的表观横向弛豫率 R2和从 DWI 中得出的 ADC 分别在低级别和高级别膀胱癌以及非肌层浸润性膀胱癌（NMIBC）和肌层浸润性膀胱癌（MIBC）之间进行计算和比较，采用 Mann-Whitney 检验。通过 ROC 分析评估 R2、ADC 及其组合的诊断性能。在 R2*（平均值 ± 标准差，16.55 ± 5.54 对 20.96 ± 7.75 s； = 0.001）和 ADC（1.62 ± 0.31 对 1.33 ± 0.21×10mm/s； < 0.001）方面，低级别和高级别膀胱癌之间存在显著差异。MIBC 的 R2显著更高（22.56 ± 8.41 对 18.06 ± 6.46 s； 0.008），ADC 显著更低（1.21 ± 0.18 对 1.53 ± 0.27×10mm/s； < 0.001）。使用 R2区分低级别和高级别组的 AUC 为 0.714，使用 ADC 的 AUC 为 0.779。使用 R2和 ADC 区分 NMIBC 和 MIBC 组的 AUC 分别为 0.682 和 0.850。除了 ADC，R2还可以作为一种定量成像生物标志物，为膀胱癌肿瘤特征提供额外信息。
