联合应用MR扩散加权成像和MR波谱成像对前列腺癌的诊断价值

Combined use of diffusion weighted MRI and ~1H MR spectroscopy in diagnosis of prostate cancer

目的探讨联合应用MR扩散加权成像(DWI)和MR波谱成像(MRS)对前列腺癌的诊断价值。方法经病理证实的32例前列腺癌患者,进行常规MRI扫描、DWI和3D^1HMRS成像。在前列腺3个连续层面、中央腺体和外周带左右两边选取兴趣区,以T_2WI表现为低信号作为肿瘤活检穿刺区。参照穿刺活检取材位置及手术病理结果,分别测量癌区和非癌区的(Cho+Cre)/Cit比值和表观扩散系数(ADC)值,并进行统计学分析。结果前列腺ADC值:癌区与非癌区比较差异有统计学意义(P<0.05)。前列腺MRS:癌区表现为Cit峰降低,(Cho+Cre)峰显著升高,(Cho+Cre)/Cit的均值为(1.94±1.43);非癌区表现为Cit峰高,(Cho+Cre)峰低,(Cho+Cre)/Cit的均值为(0.93±0.28),两者间差异有统计学意义(P<0.05)。常规MRI的敏感性为71.9%,MRI结合MRS的敏感性为87.5%,MRI、MRS、DWI联合应用的敏感性为93.7%。结论联合应用MR扩散加权像和MR波谱成像,较单独应用能提高前列腺癌检出的敏感性。

Objective To study the diagnosis of prostate cancer by combined use of diffusion weighted MRI and ^1H MR spectroscopy.Methods Prostate cancer was confirmed by pathology in 32 men. All the patients were scanned by routine MRI,then by DWI and 3D^1 HMRS. In three successive slices of prostate,regions of interest were selected at right and left sides of central gland and peripheral zone, diagnostically defined as low signal intensity in T2 weighted images within a sextant that was biopsy - positive for tumor. According to biopsy -positive and histopathologic finding, the （Cho ＋ Cre）/Cit values and its corresponding ADC value in cancerous and non cancerous regions were measured and analysed statistically. Results The mean ADC values of cancerous and non cancerous regions in prostate cancer were （0.87 ±0. 17） × 10^-3 mm^2/ s and （ 1.34 ±0.24） × 10^-3 mm^2/ s respectively, the difference in ratio between both was statistically significant（P 〈 0.05 ）. The average （ Cho ＋ Cre）/Cit values of cancerous and noncancerous regions in prostate cancer were （ 1.94 ± 1.43 ） and （0.93±0.28 ） , respectively,the difference in ratio between both was statistically significant （ P 〈0. 05）. Conventional MRI could predict with a sensitivity of 71.9% . MRI and MRS could predict with a sensitivity of 87.5%. MRI and MRS and DWI could predict with a sensitivity of 93.7%. Conclusions The combined use of diffusion weighted MRI and ^1H MR spectroscopy increases the specificity for prostate cancer detection while retaining the sensitivity compared with diffusion weighted MRI alone or MR spectroscopy alone.