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Updated: Feb 14, 2026

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PSA (<4ng/mL) が正常な男性に前立腺磁気共鳴画像検査を行うことは有意義ですか?
Pieter De Visschere1,2, Camille Berquin2,3, Pieter De Backer2,3
1Department of Radiology and Nuclear Medicine, Ghent University Hospital, 9000 Ghent, Belgium.
Cancers
|February 13, 2026
まとめ
前立腺MRIは,他の疑わしい要因が存在する場合,正常なPSAレベルを持つ男性において,臨床的に有意な前立腺がん (csPC) を検出することができます. しかし,MRIは,このグループで低い陽性予測値と高い偽陽性率を示しています.
科学分野:
- 放射線学 放射線学
- 腫瘍学 腫瘍学
- 泌尿器科 泌尿器科とは
背景:
- 正常な前立腺特異抗原 (PSA) レベルは,常に臨床的に有意な前立腺癌 (csPC) を排除するものではありません.
- 前立腺MRIは前立腺がんの検出のためにますます使用されていますが,正常なPSAを有する男性におけるその役割は評価が必要です.
研究 の 目的:
- 正常なPSAレベル (<4ng/mL) の男性におけるCSPCの検出のための磁気共鳴画像 (MRI) の性能と診断関連性を評価する.
- 異なるPSAサブグループにおけるMRIパフォーマンスを分析し,推薦の理由を特定します.
主な方法:
- PSA <4ng/mLの148人の男性を遡及的に分析した結果,前立腺MRIに誘導され,基因病理学または2年間のフォローアップが基準基準となった.
- 前立腺画像および報告データシステム (PI-RADS) を使用して前立腺MRIが報告されました; PI-RADS ≥3は陽性と考えられました.
- 性能は,国際泌尿病学会 (ISUP) のグレードグループ≥2および≥3のCSPCを検出するために評価されました.
主要な成果:
- 全体として,男性の18.9%は,MRIで検出されたISUP ≥2 csPCを92.9%の感度と39.4%の陽性予測値 (PPV) で有していた.
- ISUP ≥3 csPCの場合,MRIの感度は100%でしたが,PPVは21.2%でした.
- PSA <2ng/mLの男性では,CSPCは検出されず,MRIは33.3%のケースで偽陽性でした.
結論:
- 前立腺MRIは,他の臨床的疑わしい要因が存在する場合,正常なPSAを有する男性におけるCSPCを検出するのに価値があります.
- MRIは高い感度を示していますが,PPVは低いため,不必要な手順を避けるために慎重に解釈する必要があります.
- 偽陽性の高率とCSPCの欠如のために,PSA<2ng/mLの男性ではMRIの価値は限られています.
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