Enhancement patterns of prostate cancer in dynamic MRI

Our objective was to analyze fast-field-echo dynamic subtracted (FFE/DS) MRI data in prostate cancer, in order to recognize enhancement patterns of tumoral tissue in comparison with non-tumoral peripheral prostatic tissue. Eleven consecutive patients with prostate cancer were proposed for radical prostatectomy. Before surgery, all patients underwent endorectal coil MRI examination. In addition to standard sequences, a dynamic study was performed by FFE/DS to evaluate tumoral behavior after Gd-DTPA rapid infusion. Analysis of the imaging was made by the means of the time/signal intensity curve obtained during early contrast medium enhancement, sampling both the abnormal enhancing focal area and the opposite lobe at the level of the main prostatic tissue. A focal area of increased enhancement was observed in the site of the tumor in all cases. The time/intensity curve sampled on this area and compared with the opposite lobe demonstrated a high confidence interval of the difference of the data: mean tumor maximal intensity 1331 (SD 187) vs normal 470 (SD 139) and mean tumor rise time 103 s (SD 30) vs normal 250 (SD 38; p<0.01). In tumoral tissue, the enhancement percentage of signal intensity (SI%=pre-contrast minus post-contrast/pre-contrast x100) was 316.7%. At FFE/DS, there is a typical behavior of the time/intensity curve of contrast enhancement in prostatic cancer that might be employed in diagnosis of the disease.