Diagnostic value of minimum-intensity projection computed tomography chest in diagnosis of endobronchial lesions

Background
Fiberoptic bronchoscopy (FOB) is used to directly visualize the lumen of the trachea, as well as proximal and distal airways. It can be used to diagnose or treat abnormalities within or adjacent to these airways. However, it is an invasive procedure that may lead to several complications. Minimum-intensity projection (MinIP) in high-resolution computed tomography (CT) of the lungs is particularly useful because multiple lung diseases may present with reduced CT attenuation values.


Patients and methods
In this study, we included 115 patients admitted to the Chest Department, Mansoura University, Egypt. All patients were subjected to complete history taking, thorough physical examination, routine laboratory investigations, in addition to chest radiograph. CT and FOB were ordered for all cases.


Results
CT examination of the studied cases revealed mass in 43.5%, delayed resolved pneumonia in 30.4%, and collapse in 13% of cases. Furthermore, either of cavity, narrowing, or collapse was present in 4.3% of cases. Lesions were detected in the left lung in 43.5%, right lung in was 30.4%, and both lungs in 13% of cases. The sensitivity and specificity of MinIP was 69.4 and 100%, respectively, compared with FOB. The positive predictive value was 100%, whereas the negative predictive value was 71.4%, with an accuracy of 82.6%. The sensitivity of MinIP in the diagnosis was different according to the nature of the lesion. We found significant differences when comparing conventional CT with MinIP, especially in collapse, nodules, delayed resolved pneumonia, cavity, and narrowing. However, such a significant difference was not detected in the diagnosis of mass lesions.


Conclusion
We conclude that MinIP CT is a very important technique for detection of endobronchial lesion compared with conventional CT, and we recommend use of this technique when an endobronchial lesion is suspected.