A novel use of diffusion-weighted whole-body magnetic resonance imaging with background body signal suppression to diagnose infectious aortitis

Background: Diffusion-weighted whole-body imaging with background body signal suppression is one of the whole-body magnetic resonance imaging techniques and is effective in diagnosing inflammatory and infectious diseases. We aimed to evaluate the diagnostic performance of this modality in infectious aortitis, which remains unclear. Methods: The study participants were 32 patients with suspected infectious aortitis who underwent computed tomography and magnetic resonance imaging between September 2020 and November 2022. Sensitivity, specificity, and areas under the curve of each imaging modality were studied using a diagnosis based on a combination of imaging results, clinical symptoms, and laboratory tests. Decision curve analysis was performed to determine the benefit of adding magnetic resonance imaging to computed tomography. Results: The median age was 74 years, and 23 participants were men. Fifteen patients (47%) were diagnosed with infectious aortitis. Positive findings for infectious aortitis were identified in 19, 18, and 14 patients by computed tomography, diffusion-weighted whole-body imaging, and the combination of both modalities, respectively. Sensitivity, specificity, and area under the curve for correct diagnosis were 93.3%, 70.6%, and 0.82 (95% confidence interval 0.69?0.95), respectively for computed tomography, 93.3%, 76.5%, and 0.85% (95% confidence interval 0.73%?0.97), respectively for diffusion-weighted imaging, and 86.7%, 94.1%, and 0.90 (95% confidence interval 0.80?0.10), respectively for the combination of both modalities. Decision curve analysis reinforced the clinical benefit of combining the two imaging modalities across all ranges of the probability thresholds. Conclusions: Diffusion-weighted whole-body imaging with background body signal suppression is an effective diagnostic tool for infectious aortitis, especially when combined with computed tomography. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial This study was also registered at umin.ac.jp (UMIN R000056536). ### Funding Statement The Cardiovascular Surgery Department of East Medical Center provided funding for this study. We confirm that no financial assistance was provided by the manufacturer or distributor of the pharmaceuticals involved in the study. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study protocol was developed and approved by the Ethics Committee of Nagoya City University Hospital (control number: 60-22-0112) before data collection and analysis. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data supporting the findings of this study are available from the corresponding author, JS, upon reasonable request.