Kumar Virendra, Jagannathan N R, Kumar Rajeev, Thulkar Sanjay, Gupta S Dutta, Hemal A K, Gupta N P
Department of NMR, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
NMR Biomed. 2007 Feb;20(1):11-20. doi: 10.1002/nbm.1083.
Results of the evaluation of transrectal ultrasound (TRUS) guided needle biopsy of voxels identified as suspicious of malignancy on magnetic resonance spectroscopic imaging (MRSI) in a large cohort of men (n = 83) with abnormal digital rectal examination (DRE) [prostate specific antigen (PSA) 0-4 ng/ml] or PSA less than 10 ng/ml, are reported. Three-dimensional (1)H MRSI was carried out at 1.5 T using a pelvic-phased array coil in combination with an endorectal surface coil. Voxels were classified as suspicious of malignancy based on Cit/(Cho + Cr) metabolite ratio. TRUS-guided biopsy of suspicious voxels was performed using the z- and x-coordinates obtained from MR images and two to three cores were taken from the suspected site. A systematic sextant biopsy was also carried out. MRSI showed voxels suspicious of malignancy in 44 patients while biopsy revealed cancer in 11 patients (25%). Patients who were negative for malignancy on MRSI were also negative on biopsy. An overall sensitivity of 100%, specificity of 54%, negative predictive value of 100% and accuracy of 60% were obtained. The site of biopsy was confirmed (n = 20) as a hypo-intense area on repeat MRI while repeat MRSI revealed high choline and low citrate. The overall success rate of MRI-directed TRUS-guided biopsy of 25% was higher compared with a 9% success rate achieved without MR guidance in another group of 120 patients. Our results indicate that TRUS-guided biopsy of suspicious area identified as malignant from MRSI can be performed using the coordinates of the voxel derived from MR images. This increases the detection rate of prostate cancer in men with PSA level <10 ng/ml or abnormal DRE and also demonstrates the potential of MR in routine clinical practice.
报告了对一大群直肠指检(DRE)异常[前列腺特异性抗原(PSA)0 - 4 ng/ml]或PSA低于10 ng/ml的男性(n = 83)进行经直肠超声(TRUS)引导下针对磁共振波谱成像(MRSI)中判定为可疑恶性的体素进行穿刺活检的结果。使用盆腔相控阵线圈结合直肠内表面线圈在1.5 T下进行三维(1)H MRSI。根据Cit/(Cho + Cr)代谢物比率将体素分类为可疑恶性。使用从MR图像获得的z坐标和x坐标对可疑体素进行TRUS引导下活检,并从可疑部位获取两到三个组织芯。还进行了系统的六分区活检。MRSI显示44例患者存在可疑恶性体素,而活检发现11例患者患有癌症(25%)。MRSI上恶性为阴性的患者活检也为阴性。总体敏感性为100%,特异性为54%,阴性预测值为100%,准确性为60%。活检部位在重复MRI上被确认为低信号区(n = 20),而重复MRSI显示胆碱升高和枸橼酸盐降低。与另一组120例无MR引导的患者9%的成功率相比,MRI引导的TRUS引导活检25%的总体成功率更高。我们的结果表明,可以使用从MR图像得出的体素坐标对MRSI判定为恶性的可疑区域进行TRUS引导下活检。这提高了PSA水平<10 ng/ml或DRE异常男性前列腺癌的检出率,也证明了MR在常规临床实践中的潜力。