Use of 3D T2-weighted MR sequences for the assessment of neurovascular bundle changes after nerve-sparing radical retropubic prostatectomy (RRP): a potential diagnostic tool for optimal management of erectile dysfunction after RRP.

INTRODUCTION: Erectile dysfunction (ED) is one of the complications after radical retropubic prostatectomy (RRP), and recovery of erectile function is quantitatively related to the preservation of the neurovascular bundles (NVBs). AIM: The aim of our study was to assess, in patients submitted to a nerve-sparing RRP, the capability of a dedicated 3D isotropic magnetic resonance imaging (MRI) T2-weighted sequence in the depiction of postsurgical changes of NVB formation. METHODS: Fifty-three consecutive patients underwent a bilateral nerve-sparing RRP. Two postoperative magnetic resonance (MR) examinations and International Index of Erectile Function Five-Item (IIEF-5) questionnaire were carried out at 6 and 12 months. Morphological imaging of the postprostatectomy fossa was performed by first acquiring turbo spin echo T2-weighted sequences in the axial and coronal planes and then with 3D T2-weighted isotropic sequence on axial plane. Image findings were scored using a relative 5-point classification (0 = normal; I = mild; II = mild to moderate; III = moderate; IV = severe alterations) and correlated with postoperative IIEF-5 score questionnaire. MAIN OUTCOME MEASURES: The degree of association between the alteration score values obtained by postoperative MR morphologic evaluation for MR sequence and IIEF-5 score. RESULTS: Image interpretation was performed by two radiologists, that scoring MR alterations by the use of axial and multiplanar reconstruction 3D T2 isotropic sequence. The radiologists placed 43.30% of patients in class 0 (23/53 normal or quite normal), 32.00% in class I (17/53 mild), 11.40% in class II (6/53 mild to moderate), 7.50% in class III (4/53 moderate), and 5.70% in class IV (3/53 severe). In all cases, the correlation and regression analyses between the 3D T2 isotropic sequence and IIEF-5 score, resulted in higher coefficient values (rho = 0.45; P = 0.0010). CONCLUSION: The MRI protocol and NVB change classification score proposed in this study would represent an additional tool in the postoperative phase of those patients with ED.

2D and 3D T2-weighted MR sequences for the assessment of neurovascular bundle changes after nerve-sparing radical retropubic prostatectomy with erectile function correlation.

The aim of this study was to assess the capability of a 3D isotropic MRI T2-weighted sequence (3D T2 ISO) in the depiction of changes of neurovascular bundles (NVBs) after bilateral nerve-sparing radical retropubic prostatectomy (RRP). Furthermore, our aim was also to introduce a new MRI classification score of the NVB alteration patterns using the International Index Erectile Function Five-Item (IIEF-5) score as standard of reference. Fifty-three consecutive patients were postoperatively submitted to two MR examinations, including both 2D TSE T2-weighted (2D T2) and 3D T2 ISO sequences. Image findings were scored using a relative five-point classification and correlated with the postoperative IIEF-5 score. Radiologists attributed 13.2% of patients to class 0, 11.3% to class I, 34% to class II, 24.5% to class III, and 16.9% to class IV. With 3D T2 ISO images, the same radiologists determined 43.3% class 0, 32% class I, 11.4% class II, 7.5% class III, and 5.7% class IV. In all cases, the correlation and regression analysis between the 3D T2 ISO and IIEF-5 score resulted in higher coefficients values. The 3D sequence correlated most closely with patients' grading of erectile function.