Radiology Unit, Department of Surgical Sciences, University of Turin, Via Genova 3, 10126, Turin, Italy.
Urology Unit, Department of Surgical Sciences, University of Turin, Turin, Italy.
Abdom Radiol (NY). 2019 May;44(5):1883-1893. doi: 10.1007/s00261-019-01934-3.
To study the detection of clinically significant prostate cancer (PCa) by readers with different experience, comparing performance with biparametric magnetic resonance imaging (bmMRI) and with the reference multiparametric (mpMRI).
Retrospective analysis of 68 patients with mpMRI of the prostate at 1.5 Tesla using a 32 phased-array coil. Forty-five patients (cases) underwent radical prostatectomy, whereas 23 (controls) had a negative prostate biopsy and ≥ 2.5 years of negative follow-up. Six observers (two with 1000 cases interpreted, two with 300, two with 100) performed the analysis first with bpMRI including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps and T2-weighted (T2W) imaging in three planes and, after 1 month, with mpMRI, adding dynamic contrast enhancement (DCE). The performance was quantified by sensitivity (SNS), specificity (SPC) and area under the curve (AUC) of the ROC (Receiver Operating Characteristics) procedure.
Concordance within observers of equivalent experience was good (weighted Cohen's k ≈ 0.7). The two expert readers performed as well in bpMRI as in mpMRI (SNS = 0.91-0.96, AUC = 0.86-0.93; p ≥ 0.10); readers with 300 cases performed well in mpMRI, but significantly worse in bpMR: SNS = 0.58 versus 0.91 (p < 0.0001) and AUC = 0.73 versus 0.86 (p = 0.01); the limited experience of readers with 100 cases showed in mpMRI (SNS = 0.71; AUC = 0.77) and even more in bpMRI (SNS = 0.50; AUC = 0.68).
The study revealed the impact of the readers' experience when using bpMRI. The bpMRI without contrast media was a valid alternative for expert readers, whereas less experienced ones needed DCE to significantly boost SNS and AUC. Results indicate 700-800 cases as threshold for reliable interpretation with bpMRI.
研究不同经验的读者对临床显著前列腺癌（PCa）的检测能力，比较其与双参数磁共振成像（bmMRI）和参考多参数磁共振成像（mpMRI）的性能。
回顾性分析 68 例在 1.5T 场强下使用 32 通道相控阵线圈进行 mpMRI 的患者。45 例（病例组）接受根治性前列腺切除术，23 例（对照组）前列腺活检阴性且随访时间≥2.5 年。6 名观察者（2 名有 1000 例解读经验，2 名有 300 例，2 名有 100 例）首先分析 bpMRI 包括弥散加权成像（DWI）、表观弥散系数（ADC）图和 T2 加权成像（T2W）在三个平面，1 个月后，加入动态对比增强（DCE），使用受试者工作特征（ROC）曲线的敏感性（SNS）、特异性（SPC）和曲线下面积（AUC）定量评估性能。
经验相当的观察者之间的一致性较好（加权 Cohen's k≈0.7）。两名专家读者在 bpMRI 和 mpMRI 中的表现一样（SNS=0.91-0.96，AUC=0.86-0.93；p≥0.10）；有 300 例经验的读者在 mpMRI 中表现良好，但在 bpMR 中表现明显较差：SNS=0.58 与 0.91（p<0.0001），AUC=0.73 与 0.86（p=0.01）；100 例经验有限的读者在 mpMRI 中表现（SNS=0.71；AUC=0.77），甚至在 bpMRI 中表现更差（SNS=0.50；AUC=0.68）。
该研究揭示了读者经验在使用 bpMRI 时的影响。无对比剂的 bpMRI 是专家读者的有效替代方案，而经验较少的读者则需要 DCE 才能显著提高 SNS 和 AUC。结果表明，700-800 例是可靠解读 bpMRI 的阈值。
