Three-dimensional T2-weighted imaging using the dark blood method for detecting pulmonary embolisms: comparison with computed tomography angiography

• Published in: Japanese journal of radiology 2011-11, Vol.29 (9), p.667-672
• Main Authors: Ishiyama, Mitsutomi, Matsusako, Masaki, Oikado, Katsunori, Nishi, Yutaro, Ohi, Kuniomi, Hirano, Masaharu, Saida, Yukihisa
• Format: Article
• Language: English
• Subjects: Adult; Age; Aged; Angiography; Angiography - methods; Blood; Computed tomography; Embolism; Female; Humans; Imaging; Imaging, Three-Dimensional - methods; Lung; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medicine; Medicine & Public Health; Middle Aged; Nuclear Medicine; Prospective Studies; Pulmonary artery; Pulmonary Embolism - diagnosis; Pulmonary Embolism - diagnostic imaging; Pulmonary Embolism - pathology; Radiology; Radiotherapy; Statistical analysis; Technical Note; Tomography, X-Ray Computed - methods
• ISSN: 1867-1071; 1867-108X
• DOI: 10.1007/s11604-011-0609-3

Purpose 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). Materials and 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. Conclusion Three-dimensional T2-weighted imaging using the dark blood method appears to be principally useful for diagnosing main, lobar, and segmental PEs.