Clinical value of assessment of acute reversibility of airways obstruction in patients with COPD.

Editorials on a CT slice. Using 10 mm thick CT slices, the diagnostic yield from fiberoptic bronchoscopic procedures (FOB) was 60 percent for SPNs with the positive bronchus sign, and 30 percent for SPNs without this sign. Some SPNs were also scanned using 1.5 mm thick slices (thin-section CT), and the diagnostic yield of SPN without the positive bronchus sign dropped from 30 to 14 percent. This suggests that thin-section CT is more effective than standard CT in identifying whether lesions may be accessible by bronchoscopy. A 14 percent diagnostic yield by FOB for SPNs without the positive bronchus sign is far less than the expected 40-60 percent FOB yield reported by Cortese and McDougall5 and Radke et a16 for peripheral lung lesions. If a larger series of thin-section CT through SPN confirms the low yield of FOB for SPN without the positive bronchus sign, percutaneous needle aspiration biopsy would be the diagnostic procedure of choice for these SPNs. Using modified aspirating needles, 95 percent ofmalignant lesions and 85 percent of benign lesions can be 78 Modified aspirating needles such as 20-22 gauge Turner or Greene needles (Cook, Bloomington, IN) combine the safety ofa “skinny” needle with the ability to obtain a cytologic specimen for diagnosis of malignant SPN and a tissue core for diagnosis of benign SPN. Thin-section CT has proved itself clinically useful in identification of benign SPNs, assessment of bronchiectasis, and evaluation of focal airway disease. 9”#{176} As Naidich et al conclude, thin-section CT may also determine the best diagnostic approach for the SPN. Robert C. Levitt, M.D., F.C.C.P St. Louis