1 Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland.
2 Department of Diagnostic and Interventional Radiology, Universitätsmedizin Mainz, Mainz, Germany.
AJR Am J Roentgenol. 2019 Apr;212(4):823-829. doi: 10.2214/AJR.18.20295. Epub 2019 Feb 4.
The objective of this study was to develop a scoring system for background signal intensity changes or prostate homogeneity on prostate MRI and to assess these changes' influence on cancer detection.
This institutional review board-approved, HIPAA-compliant, retrospective study included 418 prostate MRI examinations in 385 men who subsequently underwent MRI-guided biopsy. The Likert score for suspicion of cancer assigned by the primary radiologist was extracted from the original report, and histopathologic work-up of the biopsy cores served as the reference standard. Two readers assessed the amount of changes on T2-weighted sequences and assigned a predefined prostate signal-intensity homogeneity score of 1-5 (1 = poor, extensive changes; 5 = excellent, no changes). The sensitivity and specificity of Likert scores for detection of prostate cancer and clinically significant cancer (Gleason score ≥ 3+4) were estimated in and compared between subgroups of patients with different signal-intensity homogeneity scores (≤ 2, 3, and ≥ 4).
Interreader agreement on signal-intensity homogeneity scores was substantial (κ = 0.783). Sensitivity for prostate cancer detection increased when scores were better (i.e., higher) (reader 1, from 0.41 to 0.71; reader 2, from 0.53 to 0.73; p ≤ 0.007, both readers). In the detection of significant cancer (Gleason score ≥ 3+4), sensitivity also increased with higher signal-intensity scores (reader 1, from 0.50 to 0.82; reader 2, from 0.63 to 0.86; p ≤ 0.028), though specificity decreased significantly for one reader (from 0.67 to 0.38; p = 0.009).
Background signal-intensity changes on T2-weighted images significantly limit prostate cancer detection. The proposed scoring system could improve the standardization of prostate MRI reporting and provide guidance for applying prostate MRI results appropriately in clinical decision-making.
本研究旨在建立一种前列腺 MRI 背景信号强度变化或前列腺匀质性的评分系统，并评估这些变化对癌症检测的影响。
本研究经机构审查委员会批准，并符合 HIPAA 规定，为回顾性研究，共纳入 385 名男性 418 次前列腺 MRI 检查，这些男性随后均接受了 MRI 引导下的活检。从原始报告中提取出初级放射科医生对癌症怀疑的 Likert 评分，并将活检核心的组织病理学检查作为参考标准。两名读者评估 T2 加权序列上的变化程度，并分配预先定义的前列腺信号强度均匀性评分 1-5（1=差，广泛变化；5=优，无变化）。在不同信号均匀性评分（≤2、3 和≥4）的患者亚组中，估计和比较 Likert 评分对前列腺癌和临床显著癌症（Gleason 评分≥3+4）检测的敏感性和特异性。
信号强度均匀性评分的两位读者间的一致性较好（κ=0.783）。当评分较好（即较高）时，前列腺癌的检测敏感性增加（读者 1 从 0.41 增加到 0.71；读者 2 从 0.53 增加到 0.73；均 p≤0.007）。在检测显著癌症（Gleason 评分≥3+4）时，随着信号强度评分的增加，敏感性也增加（读者 1 从 0.50 增加到 0.82；读者 2 从 0.63 增加到 0.86；均 p≤0.028），尽管一位读者的特异性显著下降（从 0.67 下降到 0.38；p=0.009）。
T2 加权图像上的背景信号强度变化显著限制了前列腺癌的检测。所提出的评分系统可以提高前列腺 MRI 报告的标准化，并为在临床决策中适当应用前列腺 MRI 结果提供指导。
