Computed tomography vs. magnetic resonance imaging of acute bacterial sinusitis: A rabbit model

Purpose: Computed topography (CT) and magnetic resonance imaging (MRI) are important, both clinically and in a research setting, in assessing bacteria l sinusitis (BS). The use of CT scanning to evaluate sinus opacification in a reversible model of rabbit acute sinusitis has been reported. MRI offers the potential for better visualization of soft tissue and fluid changes wi thin the paranasal sinuses. MRI has potential as a research tool in animal models of sinusitis. This article compares the use of CT and MRI in measuri ng maxillary sinus opacification in rabbits during experimental, reversible BS. Materials and Methods: In 2 independent trials, New Zealand White rabbits w ere imaged for baseline anatomy, and BS was generated by sinus inoculation with Staphylococcus aureus. Serial imaging was performed as a measure of th e progression and resolution of BS during the trials. Two experienced, inde pendent reviewers then scored each CT and MRI for percent opacification of the maxillary sinus. These scores were analyzed to assess the degree of agr eement between the reviewers. Results: The correlation coefficients for CT and MRI were 0.6816 and 0.3584 , respectively. The Z-statistic comparing these correlation coefficients wa s significant (P < .0001), indicating that CT is a more precise measure of reversible BS in this rabbit model. Differences in mean scan time and cost per scan were also significantly different (P < .0001), with CT being both quicker and less expensive. Conclusions: Greater interobserver consistency of scan interpretation, with less time and cost, make CT the preferred tool for measuring BS in this ra bbit model. Attributes of MRI such as better resolution of fluid-tissue int erfaces and custom surface coil design for visualization of specific anatom ic structures are discussed as they may increase the effectiveness of MRI a s an imaging modality in future sinusitis research.