Association between penile dynamic contrast-enhanced MRI-derived quantitative parameters and self-reported sexual function in patients with newly diagnosed prostate cancer

Dynamic contrast enhancement in prostate MRI as predictor of erectile function and recovery after radical prostatectomy

PURPOSE

To analyze routine preoperative prostate MRI to predict erectile function (EF) before and after radical prostatectomy (RP).

METHODS

Patients who underwent RP with an existing preoperative MRI including dynamic contrast-enhanced images and completed International Index of Erectile Function (IIEF-5) questionnaires at baseline and 12 months postoperative. They were divided into four erectile dysfunction (ED) groups according to preoperative IIEF-5 score. The perfusion quality was measured in the peripheral zone of the prostate by the ratio of signal increase 120 s after wash-in of contrast agent (Ratio120) in preoperative MRI and compared between the ED groups.

RESULTS

Ratio120 showed differences among the preoperative ED groups (p = .020) in 97 patients. According to IIEF-5 at 12 months postoperative, 43 patients were dichotomized into "no to mild" (≥17 points) and "moderate to severe" (≤16) ED groups. Ratio120 revealed differences among the postoperative ED groups (128.84% vs. 101.95%; p = .029) and stayed an independent predictor for ED in the multivariable regression analysis (adjusted for age, nerve-sparing and preoperative IIEF-5). ROC curves demonstrated an additional diagnostic benefit.

CONCLUSIONS

Preoperative MRI of the prostate may be used for the prediction of EF and postsurgical recovery after RP. This may serve as important tool in preoperative patient counseling and management of expectations.

Utility of dynamic MRA in the evaluation of male erectile dysfunction

PURPOSE

To assess the efficacy of time-resolved MR angiography (MRA) in evaluating penile vasculature in patients with clinically suspected vascular anomalies contributing to their erectile dysfunction correlating with penile doppler ultrasound (PDUS) findings and clinical outcomes after surgical intervention.

METHODS

Men (n = 26) with signs of early vascular shunting on PDUS underwent time-resolved, contrast-enhanced (0.1 mMol/kg gadobutrol at 1 ml/s followed by saline flush) 3-dimensional spoiled gradient echo T1-weighted MRA sequence performed over 3 min with 4.6 s frame rate after intracavernosal injection of an erectogenic agent. Additional T1- and T2-weighted sequences were performed for anatomic co-localization and tissue characterization. MRA images were evaluated for early filling of draining veins as well as arteriovenous malformations and fistulas and correlated with findings at surgery.

RESULTS

29 MRA examinations on 26 patients (mean age 39 years) demonstrated abnormal early venous drainage (n = 22) as well as diminutive/delayed cavernosal enhancement (n = 3), incomplete tumescence (n = 2), and combined arterial inflow/venous outflow disease (n = 1). The MRA had a concordance of 85.2% at determining the presence, or lack thereof of a shunt/AVM when compared to PDUS.

CONCLUSIONS

Time-resolved MRA allows for both temporal and spatial resolution with visualization of both arterial and venous abnormalities which may be suggested with a screening PDUS examination. This technique allows us to provide detailed anatomic information prior to any surgical intervention.

Evaluation of young men with organic erectile dysfunction

Erectile dysfunction (ED) in men under the age of 40 was once thought to be entirely psychogenic. Over the last few decades, advances in our understanding of erectile physiology and improvements in diagnostic testing have restructured our understanding of ED and its etiologies. Although psychogenic ED is more prevalent in the younger population, at least 15%-20% of these men have an organic etiology. Organic ED has been shown to be a predictor of increased future morbidity and mortality. As such, a thorough work-up should be employed for any man with complaints of sexual dysfunction. Oftentimes a treatment plan can be formulated after a focused history, physical exam and basic lab-work are conducted. However, in certain complex cases, more testing can be employed. The major organic etiologies can be subdivided into vascular, neurologic, and endocrine. Specific testing should be directed by clinical clues noted during the preliminary evaluation. These tests vary in degree of invasiveness, precision, and at times may not affect treatment. Results should be integrated into the overall clinical picture to assist in diagnosis and help guide therapy.

MRI-Derived Restriction Spectrum Imaging Cellularity Index is Associated with High Grade Prostate Cancer on Radical Prostatectomy Specimens

Purpose: We evaluate a novel magnetic resonance imaging (MRI) technique to improve detection of aggressive prostate cancer (PCa).

Materials and Methods: We performed a retrospective analysis of pre-surgical prostate MRI scans using an advanced diffusion-weighted imaging technique called restriction spectrum imaging (RSI), which can be presented as a normalized z-score statistic. Scans were acquired prior to radical prostatectomy. Prostatectomy specimens were processed using whole-mount sectioning and regions of interest (ROIs) were drawn around individual PCa tumors. Corresponding ROIs were drawn on the MRI imaging and paired with ROIs in regions with no pathology. RSI z-score and conventional apparent diffusion coefficient (ADC) values were recorded for each ROI. Paired t-test, ANOVA, and logistic regression analyses were performed.

Results: We evaluated 28 patients with 64 ROIs (28 benign and 36 PCa). The mean difference in RSI z-score (PCa ROI–Benign ROI) was 2.17 (SE = 0.11; p < 0.001) and in ADC was 551 mm²/s (SE = 80 mm²/s; paired t-test, p < 0.001). The differences in the means among all groups (benign, primary Gleason 3, and primary Gleason 4) was significant for both RSI z-score (F_3,64 = 97.7, p < 0.001) and ADC (F_3,64 = 13.9, p < 0.001). A t-test was performed on only PCa tumor ROIs (n = 36) to determine PCa aggressiveness (Gleason 3 vs. Gleason 4) revealing that RSI z-score was still significant (p = 0.03), whereas, ADC values were no longer significant (p = 0.08). In multivariable analysis adjusting for age and race, RSI z-score was associated with PCa aggressiveness (OR 10.3, 95% CI: 1.4–78.0, p = 0.02) while ADC trended to significance (p = 0.07).

Conclusion: The RSI-derived normalized cellularity index is associated with aggressive PCa as determined by pathologic Gleason scores. Further utilization of RSI techniques may serve to enhance standardized reporting systems for PCa in the future.