Ultrasound versus computed tomography in the imaging of orbital floor fractures

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.

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.

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).

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.