Diagnostic value of lung CT-scan in childhood tuberculosis

Many different methods and approaches have been applied for confirmation of tuberculosis in children. The diagnostic criteria being currently used for detection of childhood TB consist of clinical symptoms, history of close contact, radiological findings, PPD test and positive bacteriologic or pathologic findings. Since each of these methods may have false positive or negative results, it is necessary to find a better method for prompt diagnosis. This study was performed to determine the value of CT-scan as a sensitive method in detecting hilar, parenchymal and mediastinal involvements in early diagnsis of childhood TB and compare it with other diagnostic criteria. This cross-sectional comparative study was carried out on 100 children, suspicious of having primary pulmonary TB between September 1999 and September 2000 in Masih Daneshvari Hospital. All patients had prior history of close contact with smear-positive patients having active pulmonary TB. Epidemiological factors as well as radiological and microbiological findings were evaluated. Of total 100 patients, 43 were female and 57 were male. The mean age was 7.5 +/- 3.6 yrs ranging from 4 months to 14 years. Forty two were Iranian and 58 were Afghan. Thirty nine children had a positive PPD test. Bacteriological and simple chest x ray findings compatible with TB were positive in 11 and 36 patients, respectively. Pulmonary CT-scan without contrast revealed lung lesions in 55 patients while 25 of them [45.4%] had normal chest x rays. In 12 patients positive CTscan was the only positive diagnostic finding. Our results show the value of pulmonary CT-scan as a diagnostic criterion in pediatiric tuberculosis and we recommend it for early diagnosis in suspicious cases with no other positive findings