扩散加权成像与超声对血清PSA<10.0μg/L前列腺癌的诊断意义

目的：探讨扩散加权成像(DWI)与超声检查对前列腺特异性抗原(PSA)(4~10μg/L)患者前列腺癌(PCA)的诊断价值。方法收集2014年1月至2015年9月我院62例前列腺疾病患者，均行超声、常规磁共振及DWI检查，所有患者PSA均为4~10μg/L，分析DWI和表观扩散系数(ADC)图，测量感兴趣区ADC值,根据病理结果对DWI与超声诊断PCA的准确率进行分析。结果经病理证实PCA 32例，前列腺增生(BPH)30例，DWI、超声诊断PCA准确率分别为93.8%、50.0%。PCA癌灶在DWI呈明显高信号，ADC则为低信号。增生结节分为腺体增生与肌纤维增生，DWI与ADC图上信号各异。前者DWI为不均匀高信号，ADC图上呈稍高信号；后者DWI图上为低信号，ADC图上呈稍低信号。b=800 s/mm2时PCA灶、BPH外周带、腺体增生、肌纤维增生ADC值分别为(0.76±0.08)×10-3 mm2/s、(2.04±0.22)×10-3mm2/s、(1.78±0.19)×10-3 mm2/s、(1.43±0.13)×10-3mm2/s，四者之间比较差异有统计学意义(P<0.05)。结论 PCA、腺体增生与肌纤维增生在DWI及ADC上信号与ADC值差别较大。DWI能提高PSA (4~10μg/L)内PCA诊断准确率，对鉴别PCA和BPH有重要意义，明显弥补常规磁共振及超声检查的不足。

Value of diffusion weighted imaging and ultrasonography in the diagnosis of prostate cancer with PSA<10.0 g/L

Objective To investigate the diagnostic value of diffusion weighted imaging (DWI) and ultrasonog-raphy in patients of prostate cancer (PCA) with prostate specific antigen (PSA) of 4~10μg/L. Methods From January 2014 to September 2015, sixty-two patients of prostate disease in our hospital were selected, which all underwent ultraso-nography, routine magnetic resonance imaging (MRI) and DWI. PSA in all the patients was in the range of 4~10μg/L. DWI and apparent diffusion coefficient (ADC) maps were analyzed, and ADC value of the region of interest was mea-sured. The accuracy of DWI and ultrasonography was analyzed based on pathological findings. Results Thirty-two pa-tients were pathologically proved as prostate cancer, and thirty patients were pathologically proved as benign prostatic hyperplasia (BPH). The diagnostic accuracy of PCA with DWI and ultrasonography separately were 93.8%and 50.0%, respectively. PCA showed high signal intensity on DWI, and low signal intensity on ADC. Hyperplastic nodules were di-vided into glandular hyperplasia and muscle fiber hyperplasia, and the signal intensity were different on DWI and ADC. The former showed heterogeneous high signal intensity on DWI and slightly high signal intensity on ADC, while the lat-ter showed low signal intensity on DWI and slightly low signal intensity on ADC. When b=800 s/mm2, the ADC values (× 10-3 mm2/s) of PCA foci, BPH peripheral zone, glandular hyperplas, muscle fiber hyperplasia were (0.76 ± 0.08), (2.04±0.22), (1.78±0.19), (1.43±0.13), respectively, with statistically significant difference (P<0.05). Conclusion The signal intensity and ADC values were different of PCA, glandular hyperplas, muscle fiber hyperplasia on DWI and ADC. DWI can improve the diagnostic accuracy of PCA with PSA of 4~10μg/L. It has important significance for the identifica-tion of PCA and BPH, and can make up for the lack of routine magnetic resonance imaging and ultrasound examination.