title: MR imaging appearance of intraperitoneal gelatin sponge in mice.
abstract: Intraperitoneal gelatin sponge can mimic a mass lesion on magnetic resonance (MR) images. To determine the MR imaging characteristics of gelatin sponge over time, a 15 x 10 x 4-mm piece of gelatin sponge soaked in saline was surgically implanted in the peritoneal cavity of 14 mice. Two mice underwent a sham operation. Contiguous axial spin-echo images of the abdomen were obtained with T1-weighted, spin-density, and T2-weighted sequences preoperatively and over a 6-week period postoperatively. Gelatin sponge initially appears as a heterogeneous mass of low signal intensity on T1-weighted images and increasing intensity on spin-density and T2-weighted images, containing multiple round foci of very low signal intensity, attributable to air, at all sequences. Over time, signal intensity further increases and becomes more homogeneous on spin-density and T2-weighted images, although foci of air persist to 3 weeks. By 2-4 weeks, the mass is no longer discrete. Foci of air should help differentiate gelatin sponge from tumor and add gelatin sponge to the differential diagnosis of abscess.
authors.affiliation: Vaitkevicius MR Center, Harper Hospital, Wayne State University, Detroit, MI 48201.
authors.forename: E G
authors.initials: EG
authors.lastname: Hoeffner
authors.forename: M G
authors.initials: MG
authors.lastname: Crowley
authors.forename: R L
authors.initials: RL
authors.lastname: Soulen
mesh_terms: D000818:Animals; D005260:Female; D005781:Gelatin Sponge, Absorbable; D008279:Magnetic Resonance Imaging; D051379:Mice; D010529:Peritoneal Cavity / Q000473:pathology*; D015503:Surgical Sponges