Departamento de Ciencias Clínicas, Facultad de Ciencias de la Salud, Universidad de Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe, s/n. 35016, Las Palmas de Gran Canaria, Spain.
Servicio de Radiodiagnóstico, Complejo Hospitalario Universitario Insular Materno-Infantil, Av. Marítima, s/n, 35016, Las Palmas de Gran Canaria, Las Palmas, Spain.
Radiol Med. 2020 Jun;125(6):522-530. doi: 10.1007/s11547-020-01137-7. Epub 2020 Feb 4.
To assess the added value of diffusion-weighted imaging (DWI) to high-resolution T2-weighted sequences (HRT2w) in MRI detection of extramural venous infiltration (EMVI), according to the previous experience of radiologists.
A cross-sectional study of a retrospective database including 1.5 T MRI records from 100 patients with biopsy-proven rectal cancer (2011-2016; 75 male/25 female, average 63 y/o), which included primary staging (54) and post-chemoradiotherapy follow-up MRIs (46). The reference standard was histology of surgical specimens. All cases were individually blindly reviewed by ten radiologists: three specialists in abdominal radiology, three specialized in different areas and four residents. In each case, the presence of EMVI was assessed twice: first, using just HRT2w; second, with DWI added to HRT2w. The results were pooled by experience, analyzing sensitivity, specificity, accuracy (area under ROC curve), likelihood ratios, predictive values and overstaging/understaging.
Addition of DWI improved diagnostic performance by specialists radiologists, particularly post-chemoradiotherapy (accuracy 0.74-0.84; positive likelihood ratio 3.9-9.1; overstaging 16-8%), less so at primary staging (specificity 76-87.2%; overstaging 21-11%). Non-specialist radiologists also improved, but only at primary staging (accuracy 0.59-0.63). Residents showed small changes, except for notably increased sensitivity in both primary staging (35.7-43%) and post-chemoradiotherapy (41.7-58.3%) staging, at the expense of increased overstaging.
The addition of DWI improved the diagnostic performance of EMVI by experienced radiologists, downgrading overstaging, especially in post-chemoradiotherapy follow-up. It resulted in fewer changes for inexperienced radiologists (enhanced primary staging) and residents (increased sensitivity).
根据放射科医生的既往经验，评估磁共振成像（MRI）中弥散加权成像（DWI）对高分辨率 T2 加权序列（HRT2w）检测外膜静脉浸润（EMVI）的附加价值。
回顾性数据库的横断面研究，纳入了 100 例经活检证实的直肠癌患者（2011-2016 年；男性 75 例，女性 25 例，平均年龄 63 岁）的 1.5T MRI 记录，包括原发分期（54 例）和放化疗后随访 MRI（46 例）。参考标准为手术标本的组织学。所有病例均由 10 名放射科医生进行个体盲法复查：3 名腹部放射学专家、3 名专攻不同领域的专家和 4 名住院医师。在每个病例中，两次评估 EMVI 的存在：第一次仅使用 HRT2w；第二次在 HRT2w 中加入 DWI。根据经验对结果进行汇总，分析敏感度、特异度、准确度（ROC 曲线下面积）、似然比、预测值和过诊/漏诊。
DWI 的加入提高了放射科专家的诊断性能，特别是在放化疗后（准确度 0.74-0.84；阳性似然比 3.9-9.1；过诊 16-8%），在原发分期时效果较差（特异度 76-87.2%；过诊 21-11%）。非专科放射科医生也有所改善，但仅在原发分期时（准确度 0.59-0.63）。住院医师的变化较小，但在原发分期（敏感度分别为 35.7-43%和 41.7-58.3%）和放化疗后（敏感度分别为 41.7-58.3%），过诊增加，以提高敏感度为代价。
DWI 的加入提高了有经验放射科医生对 EMVI 的诊断性能，降低了过诊率，特别是在放化疗后随访中。对于缺乏经验的放射科医生（增强了原发分期）和住院医师（敏感性增加），效果变化较小。
