title: Three-dimensional T2-weighted imaging using the dark blood method for detecting pulmonary embolisms: comparison with computed tomography angiography.
abstract: OBJECTIVE
  The aim of this study was to assess the potential diagnostic value of three-dimensional T2-weighted imaging using the dark blood method for detecting pulmonary embolism (PE).
  
  
  METHODS
  Ten consecutive patients with already diagnosed acute PE (five men, five women; mean age 58.6 years, range 35-79 years) were prospectively enrolled in this study. All patients underwent lung magnetic resonance imaging (MRI) with a 1.5-T scanner. MRI was performed on the same day as CT angiography (CTA), which was undertaken to monitor treatment. Two radiologists performed a consensus evaluation of MRI followed by CTA on a per-vessel basis: the main pulmonary artery (PA), lobar PA, segmental PA, and subsegmental PA. Each modality was evaluated independently on separate days (at least 8 weeks apart). The accuracy of MRI for detecting PE was determined by comparing it with CTA results, which were used as a reference standard. Cohen's kappa analysis was used for statistical analyses.
  
  
  RESULTS
  Among the 10 patients, pulmonary emboli were seen in 6 of 20 main arteries, 22 of 60 lobar arteries, 35 of 180 segmental arteries, and 8 of 410 subsegmental arteries on CTA. The sensitivities/specificities of MRI were 100%/100% for the main PA, 90.9%/97.3% for the lobar PA, and 74.2%/97.9% for the segmental PA, respectively. Altogether, 304 (83%) of 410 subsegmental arteries were not visualized on MRI and only 1 of the 8 emboli in the subsegmental branches was depicted. The kappa values for the main, lobar, and segmental arteries were 1.0, 0.89, and 0.77, respectively.
  
  
  CONCLUSIONS
  Three-dimensional T2-weighted imaging using the dark blood method appears to be principally useful for diagnosing main, lobar, and segmental PEs.
authors.affiliation: Department of Radiology, St. Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan. mitishi@luke.or.jp
authors.forename: Mitsutomi
authors.initials: M
authors.lastname: Ishiyama
authors.forename: Masaki
authors.initials: M
authors.lastname: Matsusako
authors.forename: Katsunori
authors.initials: K
authors.lastname: Oikado
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nishi
authors.forename: Kuniomi
authors.initials: K
authors.lastname: Ohi
authors.forename: Masaharu
authors.initials: M
authors.lastname: Hirano
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Saida
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*