Ultrasound versus computed tomography in the imaging of orbital floor fractures

Purpose: The aim of the study was to investigate whether orbital ultrasonography (US) with a curved-array transducer could be an alternative imaging method to computed tomography (CT) to detect orbital wall fractures and fractures of the infraorbital rim. Materials and Methods: Fifty-eight patients with the clinical ophthalmologic or radiologic diagnosis of an orbital trauma were investigated prospectively by US and CT. The reference method was the intraoperative findings. Results: CT evaluation of the infraorbital rim yielded a sensitivity of 79%, a specificity of 90%, and an accuracy of 94%. The positive predictive value (PPV) and the negative predictive value (NPV) of the infraorbital rim reached 69% and 83%, respectively. CT evaluation of the orbital floor showed a sensitivity of 96%, a specificity of 71%, and an accuracy of 96%. PPV and NPV resulted in 71% and 93%, respectively. US investigation of the infraorbital rim, yielded a sensitivity of 77%, a specificity of 89%, and an accuracy of 97%, whereas PPV and NPV reached 65% and 83%, respectively. US investigation of the orbital floor reached a sensitivity of 94%, a specificity of 57%, and an accuracy of 96%, whereas PPV and NPV yielded 57% and 91%, respectively. No significant difference was found between US and CT in the investigation of the infraorbital rim (P = .809) and the orbital floor (P = .729). Conclusions: US with a curved-array transducer appears to be a useful alternative method in the investigation of orbital floor fractures. Further studies have to be conducted to reduce the presence of false-negative results. (C) 2004 American Association of Oral and Maxillofacial Surgeons.