title: The relation between CT findings and sputum microbiology studies in active pulmonary tuberculosis.
abstract: OBJECTIVE
  To evaluate whether CT findings suggesting active pulmonary tuberculosis correlate with sputum microbiological studies, and to determine whether CT could predict infectivity.
  
  
  METHODS
  Total 108 patients with active pulmonary tuberculosis were enrolled. We reviewed CT findings and sputum microbiological studies. Then, we analyzed the statistical difference in CT findings between the positive and negative groups of each sputum microbiological study (AFB smear, PCR, and culture). Also, we divided the patients into five groups according to sputum AFB smear grade and analyzed linear trends of CT findings between the five groups.
  
  
  RESULTS
  Both frequencies and extents of centrilobular micronodules (63% vs 38%, p=0.011 for frequency; 1.6 ± 1.6 vs 0.6 ± 1.1, p=0.001 for extent), tree-in-bud opacities (63% vs 33%, p=0.002; 1.6 ± 1.6 vs 0.5 ± 0.9, p<0.001, respectively), consolidation (98% vs 81%, p=0.003; 2.7 ± 1.5 vs 1.3 ± 1.1, p<0.001, respectively), and cavitation (86% vs 33%, p<0.001; 1.5 ± 1.2 vs 0.4 ± 0.7, p<0.001, respectively), were significantly increased in the sputum AFB-positive group than in the negative group. These four CT findings were increase in frequency and extent in the sputum PCR-positive group with or without statistical significance. They did not show significant differences between the sputum culture-positive and negative groups. As the AFB smear grade increased, frequencies and extents of centrilobular micronodules, tree-in-bud, consolidation, and cavitation also increased.
  
  
  CONCLUSIONS
  CT features representing active tuberculosis-centrilobular nodules, tree-in-bud, consolidation, and, cavitation-strongly correlate with the positivity and grading of AFB smear.
authors.affiliation: Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Ko
authors.affiliation: Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: radiodoc@catholic.ac.kr.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Chi Hong
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Sun Wha
authors.initials: SW
authors.lastname: Song
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013183:Sputum / Q000382:microbiology*; D014057:Tomography, X-Ray Computed; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Infectivity; Lung; Multidetector computed tomography; Sputum; Tuberculosis