Yamamura Jin, Salomon Georg, Buchert Ralph, Hohenstein Arne, Graessner Joachim, Huland Hartwig, Graefen Markus, Adam Gerhard, Wedegaertner Ulrike
Departments of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Germany.
J Comput Assist Tomogr. 2011 Mar-Apr;35(2):223-8. doi: 10.1097/RCT.0b013e3181fc5409.
To retrospectively evaluate the impact of diffusion-weighted imaging (DWI) on the detection of prostate cancer in comparison with sextant biopsy.
Fifty patients with clinical suspicion of prostate cancer underwent a combined endorectal-body-phased array magnetic resonance imaging examination at a 1.5 T magnetic resonance imaging (Siemens, Erlangen, Germany). The DWI was performed using b values of 50, 400, 800 s/mm. The prostate was divided into sextants, including the apex, the middle aspect, and the base for the left and right sides, separately. Regions of interest were placed in the peripheral zone of each sextant to evaluate the apparent diffusion coefficient (ADC) values. The results of the DWI were compared side by side with the findings of the histological examination of endorectal sonographically guided sextant biopsy. The sensitivity and specificity of ADC for the identification of the tumor tissue were computed for variable discrimination thresholds to evaluate its receiver operating characteristic. An association between ADC and Gleason score was tested for both the whole study group and on an individual basis using the nonparametric Spearman ρ test and the Pearson correlation, respectively.
Histopathology identified tumor tissue in 21 (42%) of the 50 patients. The ADC value was 1.65 ± 0.32 mm/s 10 in normal tissue and 0.96 ± 0.24 mm/s 10 in tumor tissue (mean ± 1 SD). The area under the receiver operating characteristic curve was 0.966. Using the discrimination threshold 1.21 mm/s 10, for example, the ADC value provided a sensitivity of 0.92 and a specificity of 0.93. There was a highly significant negative correlation between the ADC value and the Gleason score in the tumor-positive tissue probes (n = 62, ρ = -0.405, P = 0.001) in the whole study group. On the individual patient basis, the Pearson correlation revealed a mean coefficient of r = -0.89 (SD ± 0.12) with a P < 0.001.
Diffusion-weighted imaging of the prostate can be used to differentiate benign from malignant tissue in the peripheral zone. In the present study, ADC values were significantly lower in prostate cancer than in benign tissue.
回顾性评估扩散加权成像(DWI)与六分区活检相比,对前列腺癌检测的影响。
50例临床怀疑患有前列腺癌的患者在1.5T磁共振成像设备(德国埃尔朗根西门子公司)上接受了直肠内体部相控阵磁共振成像联合检查。使用b值为50、400、800s/mm²进行DWI检查。前列腺被分为六个区域,分别包括尖部、中部以及左右两侧的基部。在每个区域的外周带设置感兴趣区,以评估表观扩散系数(ADC)值。将DWI结果与直肠超声引导下六分区活检的组织学检查结果进行对比。计算不同鉴别阈值下ADC识别肿瘤组织的敏感性和特异性,以评估其受试者操作特征曲线。分别使用非参数Spearman ρ检验和Pearson相关性检验,对整个研究组以及个体层面上ADC与Gleason评分之间的相关性进行检验。
组织病理学检查在50例患者中的21例(42%)发现了肿瘤组织。正常组织的ADC值为1.65±0.32×10⁻³mm²/s,肿瘤组织的ADC值为0.96±0.24×10⁻³mm²/s(平均值±1标准差)。受试者操作特征曲线下面积为0.966。例如,使用鉴别阈值1.21×10⁻³mm²/s时,ADC值的敏感性为0.92,特异性为0.93。在整个研究组中,肿瘤阳性组织样本(n = 62,ρ = -0.405,P = 0.001)的ADC值与Gleason评分之间存在高度显著的负相关性。在个体患者层面,Pearson相关性显示平均系数r = -0.89(标准差±0.12),P < 0.