MRI and its role in the evaluation and surgical decision making in patients with challenging IPP presentations: descriptions of MRI findings and algorithm for patient management

Abstract

What ' s known on the subject? and What does the study add?It is known that magnetic resonance imaging (MRI) is safe and effective for imaging patients with infl atable penile prostheses (IPPs). Previous series have reported results of MRI for imaging series of patients with IPPs. The impact on management in particular with regard to salvage procedures is not well defi ned.This study represents the largest known experience with MRI evaluation of IPPs. This also provides an algorithm that assists with decisions regarding utilization of MRI and treatment planning based on results. OBJECTIVE• In some patients who undergo placement of an infl atable penile prosthesis (IPP) the device may function inadequately. We describe the use of magnetic resonance imaging (MRI) for anatomical localization and detection of prosthesis malrotation, angulation, displacement and erosion in IPPs with equivocal clinical examination. PATIENTS AND METHODS• We prospectively performed MRI by a defi ned protocol including T1-weighted imaging, and transaxial, sagittal and coronal fat-saturated fast spin-echo T2-weighted imaging in both defl ated and infl ated states to evaluate patients seen at our referral centre for IPP-related complaints.• We retrospectively reviewed 32 such MRI studies performed as a supplement to clinical examination between 2000 and 2008. RESULTS• Of 32 cases, 75% (24/32) underwent surgical intervention. Of these, 45% (11/24) underwent device salvage procedures including cylinder revision in 33% (8/24), cylinder replacement in 8% (2/24) and pump replacement in 4% (1/24).• MRI was most useful for determination of surgical approach in those with abnormal physical examination, and for justifi cation of either surgical or expectant management in those with indeterminate physical examination. CONCLUSIONS• MRI is safe and effective for imaging genitourinary prostheses.• We found MRI to be a valuable adjunct for evaluation of IPP-related complaints when clinical examination is equivocal as it detected a variety of prosthetic and corporal abnormalities and impacted management decisions regarding observation, replacement or device salvage procedures.• We provide technique, results and an algorithm that can be benefi cial in this complex subset of patients. KEYWORDS imaging , MRI , prosthesisStudy Type -Diagnostic (case series) Level of Evidence 4

Prevention, identification, and management of post-operative penile implant complications of infection, hematoma, and device malfunction

“…Impending extrusion of the prosthesis components may be evident with physical examination and can be confirmed if necessary through magnetic resonance imaging (MRI). At times, imaging studies may be inconclusive and surgical exploration becomes necessary to confirm the diagnosis and revise the implant ( 71 ). Distal cylindrical erosion through the corpus cavernosum with extrusion affecting the urethra, glans, or corporeal shaft can be managed through multiple methods.…”

Introduction to Imaging of Penile Prostheses: A Primer for the Radiologist

“…MRI can ascertain the optimal positioning of penile cylinders relative to the corpora cavernosa and can show fracture, kinking, and crossover of the cylinders. It also is useful in the evaluation of the pelvic reservoir and scrotal pump, thereby serving as "one-stop shop" imaging for PP evaluation [7,8,32].…”

“…Ideally, MRI should be performed with the PP in both the flaccid and inflated state. The consensus protocol recommended by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology, including the different MRI sequences and their benefits, is provided in Table 1 [7,8,35,36]. Both contrast-enhanced T1-weighted and DW images currently are optional sequences in the evaluation of prosthetic infection and show the presence and extent of collection.…”

“…The detection and management of postoperative complications are challenging, and physical examination alone is difficult to perform and is not accurate in determining the cause of prosthetic dysfunction because findings may be subtle and also because confounding factors, such as scarring from prior surgery and postoperative edema, may exist. Imaging plays a crucial role in determining the position and functional status of the prosthesis and helps in selecting the appropriate treatment: expectant management versus corrective surgery [7][8][9]. In the present article, we review the imaging of PPs, including current indications for PP, types of PP, and the available imaging armamentarium, with empha-Imaging of Penile Prostheses a third-line therapy and is indicated when medical therapy is ineffective or contraindicated as well as when vacuum devices are unsatisfactory or unacceptable.…”

Three-dimensional mapping and comparative analysis of the distal human corpus cavernosum and the inflatable penile prosthesis

“…Improvements in computed tomography (CT) and magnetic resonance imaging (MRI), offer superior definition of soft-tissue planes and definition of penile tissue. 7 Nevertheless, scans are not performed with subjects in the erect state and deformation artifacts cause a lack of fine detail limiting CT and MRI images. Rapid advances in computer technology along with three-dimensional (3D) computer-aided digitizers have improved our understanding of the human body.…”