MRI of odontogenic maxillofacial infections: diagnostic accuracy and reliability

Abstract

Objectives To determine the diagnostic accuracy of emergency magnetic resonance imaging (MRI) in odontogenic maxillofacial infections, the clinical and surgical significance of MRI findings, and whether MRI can identify the tooth responsible for the infection. Methods A retrospective cohort study reviewed 106 emergency neck MRI scans of patients with neck infections of odontogenic origin. The diagnostic accuracy of MRI in identifying abscesses was studied relative to surgical findings. Correlations were analyzed between various MRI findings and clinical results and outcomes, such as the surgical approach (intraoral vs. extraoral). The ability of MRI findings to predict the causative tooth was assessed in a blinded multi-reader setting. Results Of the 106 patients with odontogenic infections, 77 (73%) had one or more abscesses. Imaging showed a sensitivity, specificity, and accuracy of 0.95, 0.84, and 0.92, respectively, for MRI diagnosis of an odontogenic abscess. Among the imaging findings, mediastinal edema was the strongest predictor of extraoral surgery. MRI showed bone marrow edema in the majority of patients, and multi-reader assessment showed good reliability. MRI was also able to predict the causative tooth accurately. Conclusions Emergency neck MRI can accurately detect odontogenic abscesses and reliably point to the causative tooth. These results can increase the utility and reliance on emergency MRI in clinical decision-making.

Diagnostic accuracy of contrast-enhanced CT for neck abscesses: A systematic review and meta-analysis of positive predictive value

“…Thus, more accurate imaging of neck infections will likely benefit the patients. MRI has the added benefit of accurately describing soft tissue edema patterns, that have prognostic value [ 59 , 61 , 62 ].…”

“…Defined this way, the diagnosis of an abscess has substantial interobserver reliability. PPV of MRI for diagnosing surgically confirmed abscesses is very high (0.95) [58][59][60][61][62], which is clinically meaningful, because many patients with positive abscess finding on imaging undergo surgery. To put these numbers from both modalities in perspective, a PPV of 0.83 for CT may result in unnecessary surgery in approximately 1 in 6 patients, compared with 1 in 20 patients for MRI.…”

MRI of acute neck infections: evidence summary and pictorial review

“…This diagnostic accuracy is much higher than previously reported for contrast-enhanced CT, for which the PPV is about 0.80 in clinical studies [ 5 – 7 ]. High diagnostic accuracy was subsequently confirmed separately in pharyngotonsillar (accuracy 0.97) [ 10 ], odontogenic (accuracy 0.92) [ 11 ], and pediatric (accuracy 0.89) [ 8 ] neck infections. False positive and negative abscess diagnoses are rare (Fig.…”

“…7 , 8 ). Not surprisingly, larger abscesses are associated with a higher risk for ICU treatment [ 12 ], longer hospital stay [ 12 ], and higher rates of deep extension of peritonsillar abscesses [ 10 ] and extraoral surgery for odontogenic abscesses [ 11 ]. On MRI, measurement of maximal abscess diameter has high reproducibility between radiologists [ 12 ].…”

“…A practical implication is that widespread edema, especially ME, should be carefully evaluated in patients with tooth infections. Finally, ME is also the strongest predictor of extraoral surgery in patients with odontogenic infections [ 11 ].…”