CYSTIC-FIBROSIS - WHEN SHOULD HIGH-RESOLUTION COMPUTED-TOMOGRAPHY OF THE CHEST BE OBTAINED

Objective. To provide indications for high-resolution computed tomogra phy (HRCT) of the chest in patients with cystic fibrosis (CF). Design. We compared the HRCT and conventional chest radiography (CCR) scores and assessed their correlation with clinical stores and pulmonary func tion tests. Setting. Department of Pediatrics, Federico II University, Naples, Italy. Subjects. A total of 30 patients with CF 6.75 to 24 ye ars of age. Results. CCR scores correlated highly with HRCT (r = -0.8) and clinical (r = 0.5) scores, whereas total HRCT scores were not rel ated to clinical scores. Of all the specific HRCT findings, only bronc hiectasis appeared related significantly to the clinical score (r = 0. 6). Most pulmonary function tests were related to CCR and total HRCT s cores, but not to HRCT scoring of specific changes. Forced vital capac ity and CCR scores appeared the best predictors of the HRCT score (mul tiple R = 0.58 and 0.79, respectively). In patients with mild lung dis ease, HRCT detected bronchiectasis and air trapping in 57% and 71% of the cases, respectively. In patients with more abnormal chest radiogra phs, bronchiectasis and air trapping were demonstrated on HRCT in all cases. Conclusions. These findings suggest that HRCT of the chest is m ost useful in the identification of early lung abnormalities in patien ts with CF with mild respiratory symptoms, whereas for established dis ease, CCR is still the first-line imaging technique. The advantage of detecting early changes on CT imaging awaits additional confirmation, at least until early therapeutic interventions affecting significantly the final outcome of the disease are demonstrated. In patients with a dvanced disease, HRCT may be useful in the evaluation of specific lung changes when more aggressive treatment such as chest surgical interve ntions is indicated. Given the cost of the procedure and the high radi ation dosage compared with CCR, a careful assessment of the cost:benef it ratios of HRCT is strongly recommended in CF.