A role of multifactorial evaluation of prostatic 3T MRI in patients with elevated prostatic-specific antigen levels: prospective comparison with ultrasound-guided transrectal biopsy
Abstract
AIM: To assess the role of multiparametric 3T magnetic resonance (3TMRI) of the prostate in detection of the prostatic carcinoma in a male population with elevated prostatic-specific antigen (PSA) and to compare the results with those of transrectal biopsies. MATERIALS AND METHODS: A prospectively collected cohort of 191 men underwent 3T MRI before transrectal biopsy.
The evaluation consisted of the assessment of T2-weighted images, diffusion-weighted images, MR spectroscopy and the pharmacokinetic evaluation of the data obtained during the dynamic post-contrast T1 imaging. The assessment included the calculation of the blood volume and transfer constant evaluations.
The diagnosis of prostate carcinoma was based on a minimum of three positive signs obtained from MR studies--hypointensive T2 lesion, diffusion restriction, elevated choline/creatine peak in spectrum and malignant type of saturation by contrast agents. All biopsies were evaluated by a specialist in uropathology.
RESULTS: 164 patients underwent biopsy, in 27 the biopsy was omitted due to a lack or low probability of carcinoma: Overall, 84 carcinomas were found. Based on the comparison of biopsy results, 3T MRI reached a sensitivity of 97.6%, specificity of 85.0%, positive predictive value of 74.6% and negative predictive value of 96,3% respectively.
There were only three false negative findings. In three patients with very suspicious MRI findings and PSA levels over 30 ng/ml, the biopsy did not confirm carcinoma, even though it was highly suspected.
CONCLUSION: The implementation of 3T MRI in routine assessment of patients with elevated PSA should reduce the number of biopsies performed and improve the number of tumors detected due to better targeted biopsies.