title: Proton Magnetic Resonance Imaging for Initial Assessment of Isolated Mycobacterium avium Complex Pneumonia.
abstract: BACKGROUND
  Computed tomographic (CT) radiography is the reference standard for imaging Mycobacterium avium complex (MAC) lung infection. Magnetic resonance imaging (MRI) has been shown to be comparable to CT for characterizing other pulmonary inflammatory conditions, but has not been rigorously tested for imaging MAC pneumonia.
  
  
  OBJECTIVE
  To determine the feasibility of pulmonary MRI for imaging MAC pneumonia and to assess the degree of agreement between MRI and CT for assessing the anatomic features and lobar extent of MAC lung infections.
  
  
  METHODS
  Twenty-five subjects with culture-confirmed MAC pneumonia and no identified coinfecting organisms were evaluated by thoracic MRI and then by chest CT imaging performed up to 1 week later. After deidentification, first the MRI and then the CT scans were scored 2 weeks apart by two chest radiologists working independently of one another. Discrepancies were resolved by a third chest radiologist. The scans were scored for bronchiectasis, consolidation or atelectasis, abscess or sacculation, nodules, and mucus plugging using a three-point lobar scale (absent, <50% of lobe, and >50% of lobe). Agreement analyses and ordinary least products regressions were performed.
  
  
  RESULTS
  A fixed bias was found between total CT and MRI scores, with CT scoring higher on average (median difference: 4 on a scale of 48; interquartile range: 3, 6). Fixed biases were found for bronchiectasis and consolidation or atelectasis subscale scores. Both fixed and proportional biases were found between CT and MRI mucus plugging scores. No bias was found between CT and MRI nodule scores. There was nearly perfect lobar percent agreement for more conspicuous findings such as consolidation or atelectasis and abscess or sacculation.
  
  
  CONCLUSIONS
  In this exploratory study of 25 adult patients with culture-proven MAC lung infection, we found moderate agreement between MRI and CT for assessing the anatomic features and lobar extent of disease. Given the feasibility of chest MRI for this condition, future work is warranted to assess the clinical impact of MRI compared with CT in assessing progression of untreated MAC infection and response to treatment over time.
authors.affiliation: 1 Department of Radiology and.
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Chung
authors.affiliation: 2 Department of Medicine, National Jewish Health, Denver, Colorado.
authors.forename: Gwen
authors.initials: G
authors.lastname: Huitt
authors.affiliation: 3 Department of Radiology, St. Marianna University School of Medicine, Kanagawa, Japan.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yagihashi
authors.affiliation: 4 Department of Radiology, University of Kentucky, Lexington, Kentucky.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Hobbs
authors.affiliation: 5 Department of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colorado.
authors.forename: Anna V
authors.initials: AV
authors.lastname: Faino
authors.affiliation: 6 Siemens Medical Solutions USA, Inc., Salt Lake City, Utah; and.
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Bolster
authors.affiliation: 7 Radiologie Darmstadt, Gross-Gerau County Hospital and.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Biederer
authors.affiliation: 8 Hufeland Klinikum GmbH, Abteilung für Diagnostische und Interventionelle Radiologie, Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Puderbach
authors.affiliation: 1 Department of Radiology and.
authors.forename: David A
authors.initials: DA
authors.lastname: Lynch
mesh_terms: D000368:Aged; D057186:Comparative Effectiveness Research; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015269:Mycobacterium avium Complex / Q000302:isolation & purification; D015270:Mycobacterium avium-intracellulare Infection / Q000175:diagnosis / Q000503:physiopathology; D018410:Pneumonia, Bacterial / Q000175:diagnosis / Q000382:microbiology; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: atypical nontuberculous mycobacterial pneumonia; magnetic resonance imaging; nontuberculous mycobacterial pneumonia