Preclinical evaluation by flat-panel detector-based volumetric CT versus MRI of intervertebral spacers implanted in a porcine model.

Abstract

Image quality and implant detectability by conventional imaging methods are suboptimal for perioperative spinal diagnostics, primarily limited by implant-related artifacts. To evaluate the imaging quality of various intervertebral spacers examined by flat-panel detector-based volumetric computed tomography (FD-VCT) versus magnetic resonance imaging (MRI). A preclinical comparative study on an experimental porcine model. The study was performed at a university research facility. Three different intervertebral spacer types (titanium, carbon fiber-reinforced polymer, cobalt-chrome-molybdenum) were implanted in a cadaveric porcine spine and then examined by MRI using T1-weighted spin echo (T1w-SE) and turbo spin echo (T1w-TSE) sequences. Comparative imaging was performed with an experimentally approved FD-VCT prototype featuring two-dimensional and three-dimensional imaging and high isotropic spatial resolution. Data analysis focused on spacer shape, implant positioning, and implant-bone interface. Compared with MRI, and despite the use of T1w-SE and T1w-TSE sequences, the image quality and detectability of all target characteristics were better with FD-VCT absent the usual artifacts. Using its option for implant-specific imaging, the experimental FD-VCT imager allowed reliable determination of additional variables such as dimension and volume. This experimental study provides initial evidence that FD-VCT produces excellently sharp, high-accuracy, artifact-free imaging quality that is superior to MRI in distinguishing key characteristics of intervertebral implants in a preclinical setting.