Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.
Department of Pathology, Yonsei University College of Medicine, Seoul, Republic of Korea.
Clin Radiol. 2019 Nov;74(11):895.e27-895.e34. doi: 10.1016/j.crad.2019.06.014. Epub 2019 Jul 18.
To analyse the optimal time cut-off for determining positivity of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in peripheral zone (PZ) prostate cancer (PCa).
A consecutive series of 89 patients with PZ PCa who had undergone diffusion-weighted imaging (DWI) and subtraction DCE MRI were included. An experienced reader visually analysed the earliest time after contrast medium injection to visualise the best contrast between an index tumour and normal PZ on DCE MRI (i.e., best contrast time). The best contrast time cut-off for clinically significant cancer (csPCa) according to Epstein criteria or International Society of Urological Pathology (ISUP) grade ≥2 was analysed by an experienced reader, and applied to a less-experienced reader. For the index lesion of DWI category 3, the added value of DCE MRI (increased true positive and negative rates of PI-RADSv2 for csPCa) was evaluated using the cut-off time.
The best contrast time cut-off for csPCa was ≤72 seconds for Epstein criteria and ≤56 seconds for ISUP grade ≥2 by an experienced reader. The weighted kappa to determine positivity of DCE MRI was 0.622 for ≤72 seconds and 0.527 for ≤56 seconds between the two readers. The added value of DCE MRI was 55-75% by an experienced reader and 39.1-69.6% by a less-experienced reader.
For interpreting PI-RADSv2, imaging findings within 60-72 seconds following contrast media injection seem to reliably determine positivity of DCE MRI in PZ, and have added value for detecting csPCa.
分析确定周边区（PZ）前列腺癌（PCa）动态对比增强（DCE）磁共振成像（MRI）阳性的最佳时间截止值。
纳入了 89 例连续接受扩散加权成像（DWI）和减影 DCE MRI 检查的 PZ PCa 患者。一位有经验的读者对最早时间进行了视觉分析，即对比剂注射后能在 DCE MRI 上观察到指数肿瘤与正常 PZ 之间的最佳对比（即最佳对比时间）。根据 Epstein 标准或国际泌尿病理学会（ISUP）分级≥2，有经验的读者分析了最佳对比时间截止值对临床显著癌（csPCa）的影响，并将其应用于经验较少的读者。对于 DWI 类别 3 的指数病变，使用截止时间评估 DCE MRI 的附加价值（增加 PI-RADSv2 对 csPCa 的真阳性和真阴性率）。
有经验的读者确定 csPCa 的最佳对比时间截止值为 Epstein 标准≤72 秒，ISUP 分级≥2≤56 秒。两位读者之间 DCE MRI 阳性判断的加权 Kappa 值为≤72 秒时为 0.622，≤56 秒时为 0.527。DCE MRI 的附加价值为经验丰富的读者 55-75%，经验较少的读者 39.1-69.6%。
对于解读 PI-RADSv2，注射对比剂后 60-72 秒内的影像学表现似乎可以可靠地确定 PZ 中 DCE MRI 的阳性，并且对检测 csPCa 具有附加价值。
