Bilateral bronchiectasis and bronchiolitis at thin-section CT: diagnostic implications in nontuberculous mycobacterial pulmonary infection.
OBJECTIVE
To determine frequency of nontuberculous mycobacterial (NTM) pulmonary infection in patients with bilateral bronchiectasis and bronchiolitis at chest computed tomography (CT) and whether CT findings are indicative of Mycobacterium avium-intracellulare complex (MAC) infection.


METHODS
Institutional review board approved this research study; patient informed consent (not required) was obtained from all patients to perform CT. From July 2000 to December 2002, 126 consecutive patients, who were suspected of having NTM pulmonary infection at helical CT (120 kVp, 70 mA, 2.5-mm collimation, pitch of 6) with findings of bilateral bronchiectasis and bronchiolitis, were included. Of these, 105 patients underwent study for diagnosis of NTM disease. Medical records and CT scans were reviewed for final diagnoses. Clinical and chest CT findings in patients with NTM disease and those with other airway diseases were compared (unpaired t test, chi(2) test, or Fisher exact test).


RESULTS
NTM pulmonary infection was seen in 36 (34%) of 105 patients; NTM was definite in 32 (30%) and probable in four (4%). In decreasing order of frequency, organisms involved were MAC in 18 patients (50%), with M avium in 10 and M intracellulare in eight, Mycobacterium abscessus in 14 (39%), Mycobacterium kansasii in one (3%), and Mycobacterium fortuitum in one (3%); organisms were unidentifiable in two (6%). Female (P = .031) nonsmokers (P = .037) with history of treatment for Mycobacterium tuberculosis (P = .002), sputum smear positive for acid-fast bacilli (P < .001), and thin-section CT findings of bronchiolitis in more than five lobes with bronchiectasis (P = .011), lobular consolidation (P = .010), and a cavity (P < .001) were related to diagnosis of NTM pulmonary infection.


CONCLUSIONS
About one-third of patients with thin-section CT findings of bilateral bronchiectasis and bronchiolitis have NTM pulmonary infection; in these situations, MAC and M abscessus are two most frequent causative organisms. Thin-section CT findings of bronchiectasis and bronchiolitis involving more than five lobes, especially when associated with lobular consolidation or a cavity, are highly suggestive of NTM pulmonary infection.
Koh
Won-Jung
WJ
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Kangnam-Ku, Seoul 135-710, Korea.
Lee
Kyung Soo
KS
Kwon
O Jung
OJ
Jeong
Yeon Joo
YJ
Kwak
Seo-Hyun
SH
Kim
Tae Sung
TS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001987:Bronchiectasis / Q000150:complications* / Q000000981:diagnostic imaging*; D001988:Bronchiolitis / Q000150:complications* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000150:complications*; D014057:Tomography, X-Ray Computed / Q000379:methods