PURPOSE: The feasibility of noninvasive visualization of composite meshes used in ventral hernia repair by amide-proton transfer magnetic resonance imaging (APT-MRI) was explored. METHODS: Magnetization transfer asymmetry ratio images of composite meshes were obtained in vitro and in vivo from fast-spin echo acquisitions with frequency saturation offsets of ±3.5 ppm with respect to water frequency and no saturation. Three rats were assessed with APT-MRI each week for 1 month after the intraperitoneal implantation of two meshes, one on each side of the incision. One mesh was coated with collagen and the other was not. RESULTS: In vitro, meshes were delineated with APT-MRI as a thin continuous linear hypersignal located on one side of the mesh. Unlike collagen-free meshes, collagen-coated meshes were easily identified in vivo with APT-MRI during the first 3 weeks postimplantation. The composite meshes magnetization transfer asymmetry ratio (8.7 ± 2.8%) were significantly different from the muscle magnetization transfer asymmetry ratio value (-0.9 ± 1.6%). After a month, the mesh value dropped down to 1.1 ± 3.9%. Muscle and mesh magnetization transfer asymmetry ratio values were not significantly different and mesh conspicuity was no longer possible. CONCLUSION: The results suggest that APT-MRI is a promising technique for noninvasive, early postsurgical visualization of composite meshes used in ventral hernia repair.
PURPOSE: The feasibility of noninvasive visualization of composite meshes used in ventral hernia repair by amide-proton transfer magnetic resonance imaging (APT-MRI) was explored. METHODS: Magnetization transfer asymmetry ratio images of composite meshes were obtained in vitro and in vivo from fast-spin echo acquisitions with frequency saturation offsets of ±3.5 ppm with respect to water frequency and no saturation. Three rats were assessed with APT-MRI each week for 1 month after the intraperitoneal implantation of two meshes, one on each side of the incision. One mesh was coated with collagen and the other was not. RESULTS: In vitro, meshes were delineated with APT-MRI as a thin continuous linear hypersignal located on one side of the mesh. Unlike collagen-free meshes, collagen-coated meshes were easily identified in vivo with APT-MRI during the first 3 weeks postimplantation. The composite meshes magnetization transfer asymmetry ratio (8.7 ± 2.8%) were significantly different from the muscle magnetization transfer asymmetry ratio value (-0.9 ± 1.6%). After a month, the mesh value dropped down to 1.1 ± 3.9%. Muscle and mesh magnetization transfer asymmetry ratio values were not significantly different and mesh conspicuity was no longer possible. CONCLUSION: The results suggest that APT-MRI is a promising technique for noninvasive, early postsurgical visualization of composite meshes used in ventral hernia repair.