title: Injected periurethral collagen for postprostatectomy urinary incontinence: MR and CT appearance.
abstract: BACKGROUND
  Urinary incontinence, a disturbing complication of radical prostatectomy, is often treated with periurethral collagen injections to increase urethral closure and resistance to urinary outflow.
  
  
  METHODS
  Using magnetic resonance imaging and computed tomography, we studied the appearance of glutaraldehyde cross-lined bovine collagen endoscopically injected into the periurethral tissues in four men who developed urinary incontinence after radical prostatectomy. Collagen was also scanned in vitro to verify its magnetic resonance appearance.
  
  
  RESULTS
  Collagen deposits appear as well-circumscribed nodules of low to intermediate signal intensity on both T1- and T2-weighted images in the periurethral tissues or in the base of the subjacent penile bulb (base of corpus spongiosum). On contrast-enhanced computed tomography, collagen appears as a hypoattenuating nodular-filling defect within the penile bulb.
  
  
  CONCLUSIONS
  These imaging characteristics should allow differentiation of collagen from locally recurrent prostate carcinoma and avoid inappropriate work-up of benign findings.
authors.affiliation: Department of Radiology, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: D D
authors.initials: DD
authors.lastname: Maki
authors.forename: M P
authors.initials: MP
authors.lastname: Banner
authors.forename: P
authors.initials: P
authors.lastname: Ramchandani
authors.forename: A
authors.initials: A
authors.lastname: Stolpen
authors.forename: E S
authors.initials: ES
authors.lastname: Rovner
authors.forename: A J
authors.initials: AJ
authors.lastname: Wein
mesh_terms: D003094:Collagen / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D006801:Humans; D007267:Injections; D008279:Magnetic Resonance Imaging; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D011468:Prostatectomy / Q000009:adverse effects*; D011471:Prostatic Neoplasms / Q000175:diagnosis; D014057:Tomography, X-Ray Computed; D014521:Urethra / Q000000981:diagnostic imaging* / Q000473:pathology*; D014549:Urinary Incontinence / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology / Q000628:therapy*
chemical_list: D003094:Collagen