Effects of Metal Implants on Computed Tomographic Attenuation Values in the Canine Antebrachium: A Cadaveric Study.

Computed tomography (CT) of postoperative orthopedic cases can yield valuable clinical information, especially when radiographic findings are equivocal. Image quality can be adversely affected by the presence of metallic implants. Several studies evaluating metal artifacts on CT have been published in humans, but studies involving veterinary patients are limited. This study aimed to assess attenuation value changes caused by metal artifacts on adjacent anatomical structures. This prospective cadaveric study included 20 Greyhound cadaver forelimbs. The limbs underwent CT before and after application of a 316L stainless steel plate and screws along the cranial surface of the radius. Attenuation values of the radial cortex, medulla, and caudal soft tissues were compared before and after implant placement. Five anatomical sites along the antebrachium were selected for comparison: (1) at the level of a non-filled plate hole, (2) along the plate between 2 screws, (3) at the edge of the plate, and (4) 1 and (5) 3 cm proximal to the plate, respectively. The attenuation values between pre- and post-implant images were significantly different in the radial medulla, cranial, and caudal cortices at Sites 2 and 3, and in the cranial radial cortex at Site 1. No significant differences were found in the antebrachial caudal soft tissues at any site, nor at any region at Sites 4 and 5. The presence of stainless steel implants significantly affects the attenuation values of adjacent cortical and medullary bone, which may lead to image interpretation errors.