Bhatia Cathleeyakorn, Phongkitkarun Sith, Booranapitaksonti Dechaphol, Kochakarn Wachira, Chaleumsanyakorn Panas
Department of Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
J Med Assoc Thai. 2007 Jul;90(7):1391-9.
To prospectively evaluate the accuracy of transrectal ultrasonographic (TRUS)-guided biopsies by using combined magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) in patients with persistently high prostate-specific antigen (PSA) levels and negative TRUS-guided biopsy results.
Twenty-one patients (age range 50-77 years, average 61.4 years) with negative TRUS biopsy were enrolled Suspicious areas were identified by discrete low signal intensity in T2 on standard MRI. MRSI was interpreted by using spectral approach and given score of I (benign) to 5 (malignant). Suspicious voxels were localized for guided TRUS biopsy. All patients underwent sextant TRUS biopsies with up to four additional biopsies targeted at suspicious sites. Diagnostic accuracy of MRI/MRSI in patient-by-patient and voxel-by-core were analyzed.
Prostate cancer was detected in 2 of 21 patients (9.5%). The sensitivity, specificity, PPV, NPV and accuracy of combined MRI/MRSI for detection of prostate cancer were 100%, 84%, 40%, 100%, and 86%, respectively. The site of positive biopsy correlated correctly with voxels were 80%, 85%, 21%, 99% and 85% on sensitivity, specificity, PPV, NPV and accuracy, respectively.
MRI/MRSI have the potential to guide biopsy to cancer foci in patients with persistently high PSA levels and prior negative TRUS biopsy results.
通过联合磁共振成像（MRI）和磁共振波谱成像（MRSI），对前列腺特异性抗原（PSA）水平持续升高且经直肠超声（TRUS）引导下活检结果为阴性的患者，前瞻性评估TRUS引导下活检的准确性。
纳入21例TRUS活检结果为阴性的患者（年龄范围50 - 77岁，平均61.4岁）。在标准MRI的T2加权像上，通过离散的低信号强度确定可疑区域。采用光谱方法解读MRSI，并给予1分（良性）至5分（恶性）的评分。对可疑体素进行定位，以引导TRUS活检。所有患者均接受了六分区TRUS活检，并针对可疑部位额外进行了多达四次活检。分析了MRI/MRSI在逐个患者以及逐个核心体素层面的诊断准确性。
21例患者中有2例（9.5%）检测到前列腺癌。联合MRI/MRSI检测前列腺癌的敏感性、特异性、阳性预测值、阴性预测值和准确性分别为100%、84%、40%、100%和86%。活检阳性部位与体素的正确相关性在敏感性、特异性、阳性预测值、阴性预测值和准确性方面分别为80%、85%、21%、99%和85%。
对于PSA水平持续升高且既往TRUS活检结果为阴性的患者，MRI/MRSI有潜力引导活检至癌灶。
