初步结果表明，扩散加权磁共振成像可用于前列腺癌患者盆腔淋巴结的特征描述。

Preliminary results for characterization of pelvic lymph nodes in patients with prostate cancer by diffusion-weighted MR-imaging.

机构信息

Department of Radiology, Technische Universität München, Munich, Germany.

出版信息

Invest Radiol. 2010 Jan;45(1):15-23. doi: 10.1097/RLI.0b013e3181bbdc2f.

DOI:10.1097/RLI.0b013e3181bbdc2f

PMID:19996762

Abstract

OBJECTIVES

In this retrospective feasibility study diffusion-weighted magnetic resonance imaging (DWI) was evaluated as a potential tool for characterization of pelvic lymph nodes in patients with prostate cancer.

METHODS AND MATERIALS

Twenty-nine patients with prostate cancer underwent DWI of the pelvis at 1.5T by a non breath-hold SSEPI sequence using a body phased array coil with b values of 50, 300, and 600 s/mm(2) and an additional T2-weighted sequence. A total of 118 lymph nodes (>6 mm short axis) were analyzed by measuring the ADC-value with a polygon region of interest. Feasibility for ADC-measurement was assessed by comparing the ADC-value from the automatically created ADC-map (ADC(MR_unit)) with a manually calculated ACD-value (ADC(calculated)) and by using a linear-regression model for comparison with size and standard deviation of the ADC-value. Diagnostic performance was estimated by receiver operator characteristic analysis using histologic and/or clinical follow-up as standard of reference.

RESULTS

ADC(MR_unit) and ADC(calculated) showed a high correlation (r = 0.8999) with a mean percentual deviation of 6.33%. There was a highly significant difference between the mean ADC-value (x10(-3) mm(2)/s) of malignant (1.07 +/- 0.23) versus benign (1.54 +/- 0.25) lymph nodes, even in subgroup analysis for lymph nodes smaller versus larger than 10 mm. Receiver operator characteristic-analysis showed a good accuracy of the ADC-value (85.6% [101/118]; sensitivity: 86.0% [43/50]; specificity: 85.3% [53/68]) for differentiation of malignant and benign lymph nodes at a cutoff 1.30 x 10(-3) mm(2)/s. This was superior to a size-based analysis at a cutoff of 8 mm (accuracy: 66.1% [78/118]; sensitivity: 82.0% [41/50]; specificity: 54.4% [37/68]; P < 0.01).

CONCLUSIONS

DWI has the potential of being an accurate technique for analysis of pelvic lymph nodes. Moreover, our preliminary results suggest that the ADC-value might perform significantly superior to size criteria to discriminate between benign and malignant lymph nodes.

摘要

目的

本回顾性可行性研究旨在评估磁共振扩散加权成像（DWI）是否可用于诊断前列腺癌患者盆腔淋巴结的特征。

方法与材料

29 例前列腺癌患者于 1.5T 行盆腔 DWI，采用非屏气单次激发平面回波成像序列（SSEPI），应用体部相控阵线圈，b 值为 50、300 和 600 s/mm²，同时加扫 T2 加权序列。通过对直径＞6mm 的淋巴结勾画多边形感兴趣区测量 ADC 值，共分析 118 枚淋巴结。通过比较自动生成 ADC 图（ADC（MR_unit））与手动计算的 ADC 值（ADC（calculated））评估 ADC 值测量的可行性，同时采用线性回归模型与 ADC 值的大小和标准差进行比较。以组织学和（或）临床随访为标准参照，利用受试者工作特征曲线（ROC）分析评估诊断性能。

结果

ADC（MR_unit）和 ADC（calculated）高度相关（r=0.8999），平均百分比偏差为 6.33%。恶性（1.07±0.23×10⁻³mm²/s）与良性（1.54±0.25×10⁻³mm²/s）淋巴结之间的平均 ADC 值有显著差异，即使对直径＜10mm 与直径≥10mm 的淋巴结进行亚组分析也是如此。ROC 分析显示，ADC 值（cutoff 值为 1.30×10⁻³mm²/s 时，准确度为 85.6%[118 个淋巴结中的 101 个]；敏感度为 86.0%[50 个淋巴结中的 43 个]；特异度为 85.3%[68 个淋巴结中的 53 个]）区分良恶性淋巴结的准确性优于基于大小的分析（cutoff 值为 8mm 时，准确度为 66.1%[118 个淋巴结中的 78 个]；敏感度为 82.0%[50 个淋巴结中的 41 个]；特异度为 54.4%[68 个淋巴结中的 37 个]；P＜0.01）。