Different CT Reconstruction Techniques for Optical Canal Fractures：Analysis of Diagnostic Efficiency and Causes for Missed Diagnosis and Misdiagnosis
SHAO Ju-wei
XIANG Shu-tian
YANG Ya-ying
SU Wei
Abstract：Objective To analyze CT signs of optic canal ( OC) fractures and causes of missed diagnosis and misdi-agnosis so as to improve the accuracy of diagnosis. Methods A retrospective study was conducted for 60 cases with OC frac-tures and 5 cases misdiagnosed as OC fractures during April 2012 and March 2014. Results The direct CT signs of OC frac-tures included continuous interruption of bone cortex, OC collapse, narrowed canal cavity, and displacement of fragments. The indirect signs included herniation of the orbital fat involving sphenoidal and ethmoidal sinus, thickening mucous membrane of sphenoidal and ethmoidal sinus, and localized hematoma of mucous membrane. Out of 60 cases, 17 cases showed linear fractures;12 cases showed depressed fractures;8 cases showed embedded fractures;20 cases showed smashing fractures;3 cases showed mixed fractures. In 60 cases, HRCT pure axial view resulted in missed diagnosis of 19 cases, axial view in com-bination with CPR resulted in missed diagnosis of 14 cases, axial view in combination with VRT resulted in missed diagnosis of 16 cases. HRCT axial view resulted in misdiagnosis of 5 cases as OC fractures, wherein 4 cases misdiagnosed as fragments ac-tually had calcification of internal carotid and 1 misdiagnosed as canal fragment actually had ridge protruding of anterior clinoid process. The diagnostic efficiency showed that the axial view+MPR provided sensitivity of 0, the pure axial view provided specificity of 0, while the other three methods provided specificity of 100%. The AUC of receiver operating characteristic ( ROC) curve showed that HRCT axial view in combination with MPR had the best diagnostic accuracy of OC fractures. Con-clusion OC fracture should be diagnosed by HRCT axial view in combination with post-processing techniques such as MPR, CPR and VRT. HRCT axial view in combination with MPR has the best diagnostic accuracy. Application of multiple tech-niques can further reduce the rate of missed diagnosis and misdiagnosis.
Keywords：Optical canal fractureOptic nerve diseaseOptic nerve injuryTomographyspiral computedMissed diagnosis and misdiagnosis
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 97-101 )