Dynamic contrast-enhanced MRI of prostate cancer at 3 T: A study of pharmacokinetic parameters
Dynamic contrast-enhanced MRI of prostate cancer at 3 T: A study of pharmacokinetic parameters
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DOI：
10.2214/ajr.06.1329
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发表时间：
2007-10-01
影响因子：
5
通讯作者：
Choyke, Peter L.
中科院分区：
文献类型：
--
作者：
Ocak, Iclal;Bernardo, Marcelino;Choyke, Peter L.
客观的。我们研究的目的是确定与传统 T2 加权成像相比，在 3 T 下进行动态对比增强 MRI 并使用药代动力学模型进行分析是否可以提高 MRI 检测前列腺癌的诊断性能，并确定哪些药代动力学参数可用于诊断前列腺癌。 主题和方法。这项前瞻性研究纳入了 50 名经活检证实患有前列腺癌的连续患者，他们在结合了灵敏度编码 (SENSE) 心脏线圈和直肠内线圈的 3-T 扫描仪上接受了前列腺成像。活检后至少 5 周进行扫描。在三个平面上获得 T2 加权涡轮自旋回波图像，并在单剂量推注钆喷酸二葡胺 (0.1 mmol/kg) 期间获得动态对比度增强图像。评估 T2 加权和动态对比增强 MRI 的敏感性、特异性、阳性预测值 (PPV) 和阴性预测值 (NPV)。确定并比较了癌症、炎症和健康外周区域的以下药代动力学模型参数：K-trans（正向体积转移常数）、k(ep)（细胞外间隙和血浆之间的反向回流率常数）、v（每单位体积组织的细胞外间隙体积分数）以及术后 90 秒内的钆浓度曲线下面积 (AUGC) 注射.结果。经病理证实的前列腺周围区域癌症的特征是 T2 加权扫描上的低信号强度以及动态对比增强 MR 图像上的早期增强、早期冲洗或两者兼而有之。 T2加权成像的总体敏感性、特异性、PPV和NPV分别为94%、37%、50%和89%。动态对比增强MRI的敏感性、特异性、PPV和NPV分别为73%、88%、75%和75%。癌症中的 K-trans、k(ep) 和 AUGC 显着高于正常周围区域 (p < 0.001)。 v(e) 参数与前列腺癌没有显着相关性。结论。使用直肠内线圈以 3 T 进行的前列腺 MRI 可以产生高质量的 T2 加权图像；然而，通过进行动态对比增强 MRI 并使用药代动力学参数（特别是 K-trans 和 k(ep)）进行分析，可以提高前列腺癌的特异性。这些结果与已发表的 1.5 T 的结果相当。
OBJECTIVE. The objectives of our study were to determine whether dynamic contrast-enhanced MRI performed at 3 T and analyzed using a pharmacokinetic model improves the diagnostic performance of MRI for the detection of prostate cancer compared with conventional T2-weighted imaging, and to determine which pharmacokinetic parameters are useful in diagnosing prostate cancer.SUBJECTS AND METHODS. This prospective study included 50 consecutive patients with biopsy-proven prostate cancer who underwent imaging of the prostate on a 3-T scanner with a combination of a sensitivity-encoding (SENSE) cardiac coil and an endorectal coil. Scans were obtained at least 5 weeks after biopsy. T2-weighted turbo spin-echo images were obtained in three planes, and dynamic contrast-enhanced images were acquired during a single-dose bolus injection of gadopentetate dimeglumine (0.1 mmol/kg). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were estimated for T2-weighted and dynamic contrast-enhanced MRI. The following pharmacokinetic modeling parameters were determined and compared for cancer, inflammation, and healthy peripheral zone: K-trans (forward volume transfer constant), k(ep) (reverse reflux rate constant between extracellular space and plasma), v, (the fractional volume of extracellular space per unit volume of tissue), and the area under the gadolinium concentration curve (AUGC) in the first 90 seconds after injection.RESULTS. Pathologically confirmed cancers in the peripheral zone of the prostate were characterized by their low signal intensity on T2-weighted scans and by their early enhancement, early washout, or both on dynamic contrast-enhanced MR images. The overall sensitivity, specificity, PPV, and NPV of T2-weighted imaging were 94%, 37%, 50%, and 89%, respectively. The sensitivity, specificity, PPV, and NPV of dynamic contrast-enhanced MRI were 73%, 88%, 75%, and 75%, respectively. K-trans, k(ep), and AUGC were significantly higher (p < 0.001) in cancer than in normal peripheral zone. The v(e) parameter was not significantly associated with prostate cancer.CONCLUSION. MRI of the prostate performed at 3 T using an endorectal coil produces high-quality T2-weighted images; however, specificity for prostate cancer is improved by also performing dynamic contrast-enhanced MRI and using pharmacokinetic parameters, particularly K-trans and k(ep), for analysis. These results are comparable to published results at 1.5 T.