Comparison of diagnostic accuracy of ultrasonography and cone beam computed tomography in orbital floor fracture in patients referred to oral and maxillofacial surgery department of Tabriz Imam Reza Medical Research and Training center in 2014-15

Abstract

Fractures in the orbital floor are very common. A traditional approach in dealing with patients with orbital floor fractures relies on both clinical findings and imaging techniques, among which conventional computed tomography (CT) is generally regarded as the method of choice. This accurate imaging technique, however, bear some limitations that hinder its liberal use including considerable cost, unavailability, and the hazard of high radiation exposures. To obviate these shortcomings, some investigators have proposed ultrasonography and cone beam CT (CBCT) instead. This study sought to compare the diagnostic performance of these two modalities in detecting orbital floor fractures. Methods & Materials A total of 60 patients with CT confirmed orbital floor fractures (cases, n=30) and intact orbital bones (controls, n=30) were recruited from a referral teaching imaging center. An Experience sonographer blinded to the grouping performed orbital ultrasound examinations using a standard ultrasound machine equipped with a linear array transducer (7-10 MHz). Another expert oral and maxillofacial radiologist reviewed the CBCT scans. The diagnostic performance of orbital ultrasonography and CBCT was reported individually. Results The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of orbital ultrasonography in detecting orbital floor fractures were 93.33%, 100%, 100% and 93.75%, respectively. The corresponding values for the CBCT were 96.67%, 93.33%, 93.55%, and 96.55%, respectively. Conclusion Both ultrasonography with linear array transducers and CBCT are almost equally accurate in the diagnosis of orbital floor fractures and could be considered as suitable alternatives to conventional multislice CT.