ABSTRACT
PURPOSE: To evaluate changes in tuberculous cavities, one of the major factors used to determine the activityof tubereulosis, by high-resolution CT(HRCT) in active pulmonary tuberculosis patients after antituberculoustherapy. MATERIALS AND METHODS: The HRCT findings of 41 patients with active tuberculosis were analyzed withparticular emphasis on the appearance of tuberculous cavities before and after therapy. We measured the largestdiameter and maximal wall thickness of the cavities, as well as accompanying changes occurring during follow-up.The mean interval between initial and follow-up study was 8.7 months(minimum:4.1, maximum:33.2;S.D.: +/-5.0) andthe mean duration of antituberculous therapy was 7.5 months(minimum:4.7, maximum:14.8;S.D.: RESULTS: Among 41patients, 54 cavities were found on initial HRCT. Thirty one(57.4%) of these disappeared during follow up HRCTwith residual changes such as residual fibrotic scar(n=15), granuloma(10), paracicatrical emphysema(7),calcification(3), traction bronchiectasis(3), consolidation(3) and bullous emphysema(1). Twenty three of thecavities(42.6%) decreased in size and wall thickness, but did not disappear completely during follow-upexamination. Mean largest diameter and maximal thickness of 23 cavities were 32.0mm(+/-13.9) and 7.9mm(+/-4.8) oninitial HRCT, falling to 20.9mm(+/-12.5) and 4.1mm(+/-2.6), respectively, during follow-up HRCT. Among four patientswho underwent a second follow-up, the largest diameter and maximal thickness of the cavities decreasedcontinuously. In two patients, however, the cavities did not did not disappeas, though in the other two they haddisappeared by the time follow-up HRCT was performed a second time. CONCLUSION: During follow-up HRCT afterantituberculous therapy(mean duration of 7.5 months), 57.4%(31/54) of cavities were seen to have disappeared, withresidual changes such as fibrotic scars, granulomas, paracicatrical emphysema and calcification ; 42.6% of thecavitivies still remained, however, with retractive and fibrotic change. Such fibrotic and retractive changesshould not, therefore, be taken as indicative of active tuberculosis, especially in patients who have successfullycompleted their medication.