Reliabilit�t der sonographischen Diagnostik von Orbitabodenfrakturen und Frakturen des Infraorbitalrandes

Intrarater reliability in the ultrasound diagnosis of medial and lateral orbital wall fractures with a curved array transducer

PURPOSE

The aims of the study were to document the effectiveness of ultrasound (US) in diagnosing orbital wall fractures when compared with computed tomography (CT) and to measure the intraobserver reliability of US using a curved array transducer.

MATERIALS AND METHODS

From December 2003 to March 2004, 13 patients with the clinical diagnosis of an orbital trauma were investigated prospectively by CT (reference) and 2 US investigators. Both orbits were investigated. Sensitivity, specificity, accuracy, and positive and negative predictive value were calculated. The statistical difference between the 2 US investigators was calculated by a chi-square test. The interrater reliability was calculated using the lambda coefficient. Values below 0.4 represent poor reliability, between 0.4 and 0.75 represent fair to good reliability, and a score > 0.75 is graded as excellent reliability.

RESULTS

The comparison of the results of the 2 US investigators by the chi-square test showed P values of .385 for the medial orbital wall and .638 for the lateral orbital wall, which shows no significant difference. The lambda-value for the investigation of the medial orbital wall reached 0.429, 0.714, and 0.750. The lambda-value for the investigation of the lateral orbital wall yielded 0.647, 0.750, and 0.882. These values show a good and excellent inter-rater reliability.

CONCLUSION

The US investigation does not yet reach the diagnostic quality of CT. US could be a helpful diagnostic imaging tool in cases with clear clinical symptoms. The results of the current study and the previously published results imply that US has the potential to reach the same diagnostic quality as CT in the future, but further studies must be performed to improve the diagnostic quality of the method.