前列腺增生和前列腺癌的MRI和MRS表现

目的　分析良性前列腺增生 (BPH)和前列腺癌 (PC)的MR和MRS的表现 ,探讨MRS在前列腺病变诊断中的价值。资料与方法　回顾分析经病理证实的 2 7例 (BPH 1 7例 ,PC 1 0例 )患者的临床资料及MRI和MRS所见。MRI分析指标为前列腺大小和形态、病变位置、信号特点和肿瘤侵犯程度。MRS观察枸橼酸盐 (Citr)和胆碱复合物(Cho)化学位移及其比值。结果　 1 2例 ( 1 2 / 1 7,70 .6 %)BPHT1 WI上前列腺不规则增大 ,呈均匀的低信号 ,5例( 5 / 1 7,2 9.4 %)前列腺大小、形态正常 ;T2 WI上前列腺中央腺体显著增大 ,与外周带高信号分界清楚 ,1 4例 ( 82 .4 %)增生腺体表现为多个大小不等的圆形低信号和高信号结节灶 ,3例 ( 1 7.6 %)表现为弥漫性低信号 ;MRS上Citr波峰升高 ,Citr/Cho比值增大。 1 0例PCT2 WI上高信号外周带内见局灶性低信号区 ;4例位于前列腺包膜内 ,6例前列腺包膜受累 ,3例侵犯精囊 ,2例侵犯血管神经束 ,1例侵犯膀胱 ,1例盆腔内见多个肿大淋巴结 ,部分相互融合成块。MRS上Citr峰明显下降 ,Cho峰升高 ,Citr/Cho比值明显下降 ,与BPH比较有显著性差异 (P <0 .0 5 )。结论　MRI能很好地反映BPH特点和判断PC包膜内、外受累 ;MRS能提供前列腺组织的代谢信息有助于鉴别PC和BPH。

Benign Hyperplasia and Carcinoma of Prostate Gland: MR Imaging and MR Spectroscopy Findings

Objective To describe MR imaging (MRI) and spectroscopic (MRS) appearances of benign hyperplasia and carcinoma of the prostate, and to evaluate MRS in the diagnosis of prostate diseases.Materials and Methods Clinical data together with MRI and MRS findings were reviewed retrospectively in 27 patients with pathologically-confirmed prostate diseases, which included 17 cases with benign prostate hyperplasia (BPH) and 10 cases with prostate carcinoma (PC). MRI observation was focused on the size of the gland, the location of the lesion, the signal features and the extent of the tumor. MRS observation included the chemical shift of citrate (Citr) and choline (Cho) spectra, and the ratio of Citr/Cho.Results On T 1WI, irregular enlargement of the prostate gland with homogeneous low-signal was found in 12 BPH (70%), while in 5 cases (30%) the gland showed normal size and contour. On T 2WI, marked enlargement of the central part of the gland with well-defined high-signal peripheral zone was seen in all 17 cases of BHP, in 14 (82.4%) of which the hyperplasia presented as several different-sized round low-signal or high-signal nodular lesions. In the remaining 3 cases (17.6%), the lesions were characterized by diffuse low signal. On MRS, elevated Citr peak with increased Citr/Cho ratio was noted. In all 10 patients with PC, localized low-signal area in the peripheral zone was observed. The tumor was localized within the prostatic capsule in 4 cases. The affected structures included prostatic capsule (n=6), seminal vesicle (n=3), neurovascular bundles (n=2), bladder (n=1) and pelvic lymph nodes fused in mass (n=1). On MRS, citrate peak was obviously declined and choline peak was ascended with the Citr/Cho ratio being significantly dropped (P<0.05 compared with that in BPH).Conclusion (1) MRI can well display BPH features and show the involvement of the prostatic capsule in PC. (2) MRS can provide the metabolic information of prostatic parenchyma, which is very helpful for the differentiation of BPH with PC.