CT CHARECTERIZATION OF CAVITORY LUNG LESIONS

Abstract

Summary Background : A cavity is a gas-containing  space  surrounded  by complete  wall  which  is 3mm or greater in thickness. Fleischner socity defines a cavity as a gas filled space within a zone of pulmonary consolidation , mass or nodule. Cavities are commonly encountered lesions in the lungs on chest radiography and chest computed tomography. The differential diagnosis of such lesions is broad because many different processes of congenital or acquired origin can cause these abnormalities  . The aim of this study :  To assess the role and value of CT in dignosing the nature and causes of pulmonary cavitary lesions. Patients and methods : Thirty-six patients ((16 (44.5 %) male and 20 (55.5 %) female, range in age from 1 – 80 years with mean age (35.6 % years) )) were enrolled for this prospective cross sectional  study. Three  sets  of  CT  images were  obtained (lung ,  mediastinal  & bone windows ) to all patients. Sixteen patient underwent surgery, the resected specimens were sent for histopathology examination. Bronchoscopy was performed for 27 patient, bronchial wash sent for cytology, AFB, in addition to culture and sensitivity test. Results : Fourteen  (39 %) patients with cavitary lung lesions proved to be ruptured H.C., 8 (22 %) cavitary TB ,7 (19.4 %) Bronchogenic carcinoma, 3 (8.4 %) pyogenic abscess, 2 (5.6 %) metastases and 2(5.6 %) were other lesions (sequestration and W.G.). In this study ruptured HC commonly seen  in the Rt lower lobe (64%) ,. Air-fluid level is demonstrated in (35.6 %), daughter cyst sign (43 %), empty cavity sign (21.4 %). The cavites commonly  solitary (85.7 %). ,  thin wall (71.4 %) &  smooth contour (78.6 %). Most cavitory neoplasm encountered  were bronchogenic carcinoma7 ( 85.7 %), most are sequamous type(n=6) , all cases seen with wall nodulation (N=7), most are thick wall (N=5). TB with cavitation that located in RUL (n=5), LLL (n=3). Thin wall cavities (n=6). Thick wall cavities (n=2), single cavity   (n=5), multiple cavity (n=3), associated pleural effusion (n=3) and cavity with fluid level (n=2). Three patient present with cavitation due to pyogemic abscess. Right lung location (n=2), left lung (n=1), solitary (n=2), multiple (n=1), thin wall (n=2), thick wall (n=1), irregular wall (n=3), fluid level(s) (n=3) associated consolidation (n=1). Conclusion : Characterization of cavitary lesions by spiral CT of lung can narrow the list of differential diagnosis. CT of the chest is valuable procedure in characterizing cavitary diseases. Morphology, location, distribution and associated radiological finding provide important clues to the nature of the underlining diseases.