The Value Of MRI,MRS In Combination With PSA In The Differentiation Of Prostate Carcinoma And Benign Prostate Hyperplasia

Objective: To explore the value of the combination of MRI, MR spectroscopy (MRS) and prostate specific antigen (PSA) in the differentiation of prostate carcinoma (PCa) and benign prostate hyperplasia (BPH).Methods: 31 cases of PCa and 41 cases of BPH proven by biopsy, operation or follow-up with conventional MRI data were collected, in which 26 (12 PCa and 14 BPH) cases underwent MRS examination. The shape of prostate and the location, the signal features and the extension of lesions were observed on conventional MR images. On MRS, observed the peak of citrate (Cit), choline (Cho) and creatine (Cre), and calculated the ratio of (Cho + Cre)/ Cit (CC/C). The difference of CC/C between PCa and BPH was analyzed to find whether there was statistically significant or not with t test. 58 cases (29 PCa and 29 BPH) underwent PSA examination, and recorded the PSA data. The sensitivity, specificity and accuracy were compared in the differentiation of PCa and BPH with MRI, MRS, PSA and the combination of these three methods.Results: In 31 cases of PCa, 21 cases were located in peripheral zone (PZ), 2 cases in central gland (CG), and another 8 cases involved both PZ and CG. On T2WI, all PCa appeared as nodular or patchy hypointensity. 8 cases of PCa were localized within prostatic capsule, and 23 cases of PCa broke out the capsule. In 41 cases of BPH, 39 cases were located in CG, and 2 cases in PZ. On T2WI, 18 cases appeared as diffuse mixed signal, and 23 cases appeared as different-sized round or nodular hyperintensity (17 cases)or hypointensity (6 cases). MRS showed Cit peak descended, Cho peak ascended and the average ratio of CC/C ascended in PCa; while in BPH, Cit peak ascended, Cho peak remained normal and the average ratio of CC/C descended. The average ratio of CC/C in 12 cases of PCa and 14 cases of BPH was 2.34±1.21 and 0.79±0.25, respectively. There was significant difference between these two groups (t = 4.327,P <0.001). The PSA range in 29 cases of PCa was from 3.22 to 2262 ng/ml;in these 29 cases, the PSA with 27 cases was more than 10 ng/ml, and 2 cases was less than 10 ng/ml. The PSA range in 29 cases of BPH was from 1.16 to 111 ng/ml; in these 29 cases, the PSA with 14 cases was more than 10 ng/ml, and 15 cases was less than 10 ng/ml. The sensitivity of PSA in the differentiation of PCa and BPH was high (93.1%), but the specificity and accuracy were low (51.7% and 72.4%, respectively). The sensitivity, specificity and accuracy with MRI and MRS were more than 70% in the differentiation of PCa and BPH, and with the combination of MRI and MRS had increased to 83.3%, 92.9%, 88.5%, respectively, and after with the combination of PSA had increased to 100%, 92.9%, 96.2%, respectively.Conclusions: The combination of MRI, MRS and PSA had significantly increased the diagnosis accuracy in the differentiation of PCa and BPH.