1.5T 与 3T 磁共振动态对比增强扫描在前列腺癌中的扫描比较

Interscanner comparison of dynamic contrast-enhanced MRI in prostate cancer: 1.5 versus 3 T MRI.

机构信息

Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.

出版信息

Invest Radiol. 2013 Feb;48(2):92-7. doi: 10.1097/RLI.0b013e31827bbcbe.

DOI:10.1097/RLI.0b013e31827bbcbe

PMID:23249646

Abstract

PURPOSE

The aim of the study was the comparison of the diagnostic potential of dynamic contrast-enhanced magnetic resonance imaging to differentiate between prostate carcinoma and normal prostate tissue as well as prostatitis at 2 different field strengths: 1.5 versus 3 T.

METHODS

Sixty-six patients with biopsy and/or prostatectomy of the prostate were included in the study. Magnetic resonance imaging was performed at 1.5 T in 20 patients with biopsy-proven prostate cancer (PC) and in 8 patients with prostatitis; at 3 T, we analyzed 27 patients with prostatectomy-proven PC and 11 patients with prostatitis. All examinations were performed using a combined body and endorectal coil protocol and a 2-dimensional TurboFLASH T1-weighted gradient echo sequence to calculate plasma flow (PF) and mean transit time (MTT) values. A total of 28 of 38 areas of normal prostate tissue, 20 of 27 areas of PC, and 8 of 11 prostatitis were analyzed at 1.5 or 3T. For the normalization, we calculated PC/normal and prostatitis/normal tissue ratios of PF and MTT for each patient.

RESULTS

Prostate cancer showed higher PF (P < 0.0001) and shorter MTT (P < 0.0001) at 3 T and at 1.5 T (P < 0.0001 for PF and P = 0.0016 for MTT) compared with the normal tissue. In comparison with the normal tissue, prostatitis had a statistically significant higher PF at 1.5 T (P = 0.0156) but not at 3 T (P = 0.17) and no significantly shorter MTT values both at 3 (P = 0.15) and 1.5 T (P = 0.25). Sensitivity and specificity for differentiating PC from prostatitis with PF were 46% and 88% at 1.5 T (cutoff ratio, 2.3) and 89% and 73% at 3 T (cutoff ratio, 1.2), respectively. Sensitivity and specificity for MTT were 77% and 100% at 1.5 T (cutoff ratio, 0.7) and 70% and 100% at 3 T (cutoff ratio, 0.6), respectively. We found no significant relationship between the Gleason score and PF/MTT (P = 0.17/0.11 for 1.5 T and P = 0.23/0.18 for 3 T).

CONCLUSIONS

The differentiation between PC and the normal tissue is possible with both field strengths. Prostate cancer can be better distinguished from prostatitis at 3 T compared with 1.5 T. The differentiation between prostatitis and the normal tissue is limited at both field strengths.

摘要

目的

本研究旨在比较动态对比增强磁共振成像在两种不同场强（1.5 与 3 T）下鉴别前列腺癌与正常前列腺组织以及前列腺炎的诊断潜力。

方法

本研究纳入了 66 例经活检和/或前列腺切除术确诊的前列腺患者。20 例经活检证实的前列腺癌（PC）患者和 8 例前列腺炎患者在 1.5 T 进行磁共振成像检查；27 例经前列腺切除术证实的 PC 患者和 11 例前列腺炎患者在 3 T 进行磁共振成像检查。所有检查均采用体部和直肠内线圈联合方案及二维 TurboFLASH T1 加权梯度回波序列进行，以计算血浆流量（PF）和平均通过时间（MTT）值。在 1.5 或 3 T 下对 38 个正常前列腺组织区域中的 28 个、27 个 PC 区域中的 20 个和 11 个前列腺炎区域中的 8 个进行了分析。为了进行归一化，我们为每位患者计算了 PF 和 MTT 的 PC/正常和前列腺炎/正常组织比值。

结果

与正常组织相比，PC 在 3 T 和 1.5 T 下的 PF（P<0.0001）更高（P<0.0001），MTT 更短（P<0.0001）。与正常组织相比，前列腺炎在 1.5 T 下的 PF 显著更高（P=0.0156），但在 3 T 下并无统计学差异（P=0.17），且在 3 T（P=0.15）和 1.5 T（P=0.25）下 MTT 值均无明显缩短。以 PF 区分 PC 与前列腺炎的敏感性和特异性在 1.5 T 时分别为 46%和 88%（临界比值，2.3），在 3 T 时分别为 89%和 73%（临界比值，1.2）。MTT 的敏感性和特异性在 1.5 T 时分别为 77%和 100%（临界比值，0.7），在 3 T 时分别为 70%和 100%（临界比值，0.6）。我们未发现 Gleason 评分与 PF/MTT 之间存在显著相关性（1.5 T 时 P=0.17/0.11，3 T 时 P=0.23/0.18）。