肉芽肿性前列腺炎的MRI诊断价值

Evaluation of MRI in Diagnosing Granulomatous Prostatitis

目的探讨肉芽肿性前列腺炎(GP)的MRI表现及特征。方法回顾性分析经病理证实的10例GP患者的临床及影像学表现。临床表现为不同程度的排尿困难,4例起病时伴尿频、尿急,伴有发热及血尿各1例,PSA均正常或轻度升高。所有患者均行常规MRI及DWI检查。结果 10例GP的MRI表现可分为两种类型:结节型和弥漫型。结节型2例,表现为中央带及外周带多发大小不等结节,信号特征为T2WI呈极低信号,与肌肉相类似,DWI及ADC上均呈稍低信号,其中1例可见脓肿形成。弥漫型8例,表现为外周带弥漫性受累,多为双侧受累(6/8),受累外周带呈肿胀性改变,其信号特征为T2WI上信号弥漫性减低,与坐骨骨髓呈等或稍高信号,DWI上扩散受限,其中有4例合并脓肿形成,1例合并中央带受累。结论 GP的MRI表现可分为结节型和弥漫型,结节型的特征为T2WI上呈与肌肉类似的极低信号,弥漫型的特征为外周带肿胀性改变。

Objective To investigate MRI features of granulomatous prostatitis. Methods The clinical data and imaging materials of 10 patients with pathologically-proved granulomatous prostatitis were retrospectively analyzed. Clinically, the patients complained of different degrees of dysuria, accompanied by frequent micturition and urgency micturition （ n = 4 ） , fever （ n = 1 ） and hematuria （ n = 1 ）. Serum PSA level was normal or slightly elevated. Routine MRI and DWI were performed in all patients. The MRI findings were analyzed. Results According to MRI manifestations of the granulomatans prostatitis in the 10 patients, the lesions were divided into nodular type （n =2） and diffuse type （n =8）. The granulomatous prostatitis of nodular type was characterized by muhiple nodules with different sizes located at the central and peripheral zones, the lesions showed extremely-low signal on T2WI similar to muscle signal, while slightly low signal on DWI and ADC, and abscess formation was observed in one case. The granulomatous prostatitis of diffuse type presented as diffuse involvement of peripheral zone, usually bilateral （ 6/8 ） , the involved peripheral zone was swelling, which showed diffuse low signal on T2WI similar to that of sciatic bone marrow, while on DWI the diffusion was limited; abscess formation was detected in 4 cases and central zone involvement was seen in one case. Conclusion On the MRI, the granulomatous prostatitis can be classified into nodular type and diffuse type. The markedly lower signal intensity on T2 WI is the characteristic finding of nodular type, while peripheral zone swelling is the imaging feature of diffuse type.