title: Lung perfusion with dual-energy multi-detector row CT: can it help recognize ground glass opacities of vascular origin?
abstract: OBJECTIVE
  The aim of this study was to evaluate whether the spectral characterization of the iodine content of lung microcirculation could help identify ground-glass opacity (GGO) of vascular origin.
  
  
  METHODS
  Thirty-five consecutive patients with GGO of bronchioloalveolar (group 1; n = 24) and vascular (group 2; n = 11) origin underwent dual-energy multi-detector computed tomographic angiography of the chest using a standard injection protocol. For each patient, two radiologists evaluated by consensus the presence, location, and extent of GGO on diagnostic computed tomographic scans (ie, contiguous 1-mm-thick averaged images from both tubes) and characteristics of the corresponding areas on perfusion scans.
  
  
  RESULTS
  A total of 443 segments with GGO were depicted on the diagnostic scans (group 1, n = 231; group 2, n = 212), always intermingled with areas of normal lung attenuation, with a mean of 12.7 segments with GGO per patient. Areas of GGO were located at the level of the upper lobes (n = 128), middle lobe and/or lingula (n = 81), and lower (n = 234) lobes, involving <25% (n = 165), 25% to 50% (n = 103), 50% to 75% (n = 155), and >75% (n = 20) of the segmental surface. The overall quality of perfusion scans was rated as interpretable in all patients. Perfusion scans depicted areas of hyperattenuation within segments of GGO with a significantly higher frequency in group 2 (211 of 212 [99.5%]) than in group 1 (27 of 231 [12%]) (P < .0001). Hyperattenuated areas of vascular origin were observed to match the areas of GGO in surface (203 of 211 [96%]) and contours (208 of 211 [98.6%]).
  
  
  CONCLUSIONS
  Dual-energy computed tomography can help recognize GGO of vascular origin.
authors.affiliation: Department of Thoracic Imaging, Hospital Calmette, University Center of Lille, Lille, France.
authors.forename: François
authors.initials: F
authors.lastname: Pontana
authors.forename: Martine
authors.initials: M
authors.lastname: Remy-Jardin
authors.forename: Alain
authors.initials: A
authors.lastname: Duhamel
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Faivre
authors.forename: Benoit
authors.initials: B
authors.lastname: Wallaert
authors.forename: Jacques
authors.initials: J
authors.lastname: Remy
mesh_terms: D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*