title: Iodine Distribution Map in Dual-Energy Computed Tomography Pulmonary Artery Imaging with Rapid kVp Switching for the Diagnostic Analysis and Quantitative Evaluation of Acute Pulmonary Embolism.
abstract: OBJECTIVE
  To assess the diagnostic value of dual-energy (DE) computed tomography pulmonary angiography (CTPA) for acute pulmonary embolism (PE) using a helical DE scan mode with rapid kVp switching.
  
  
  METHODS
  Seventy-six patients with suspected acute PE underwent DE CTPA. Two readers independently assessed and measured the iodine maps. CTPA images were assessed for the presence, location, and degree of PE as the standard of reference. Iodine maps were used to identify the perfusion defect (PD), and the diagnostic accuracy of iodine maps was calculated. The iodine concentrations of PDs and normal lung parenchyma were also measured and compared.
  
  
  RESULTS
  A per-patient analysis showed the 84.6% sensitivity and 96.0% specificity of iodine map for PE, and on per-segment analysis, the sensitivity and specificity for PE were 82.9% and 99.6%, respectively. Intraobserver and interobserver variability correlations were excellent, with k values from 0.806 to 1.000. Quantitative analysis showed there was a significant difference for iodine concentration between circumscribed/patchy PDs or wedge-shaped PDs consistent with PE and normal lung parenchyma (P < .05). The intraobserver reliability of reader 1 was from 0.928 to 0.997, and reader 2 was from 0.912 to 0.995. And, the interobserver reliability between two readers was from 0.967 to 0.999.
  
  
  CONCLUSIONS
  CTPA based on DE scanning with rapid kVp switching can provide both morphologic analysis and quantitative evaluation of PD related to acute PE in addition to standard CTPA data. Quantification of iodine concentration may be helpful for identifying the presence or absence of PE.
authors.affiliation: Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China.
authors.forename: Xiang-Ran
authors.initials: XR
authors.lastname: Cai
authors.affiliation: Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China.
authors.forename: You-Zhen
authors.initials: YZ
authors.lastname: Feng
authors.affiliation: Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China.
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Xian
authors.affiliation: Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China.
authors.forename: Wen-Cai
authors.initials: WC
authors.lastname: Yang
authors.affiliation: Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China.
authors.forename: Xu-Kai
authors.initials: XK
authors.lastname: Mo
authors.affiliation: Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China. Electronic address: xiaobaiwang@163.com.
authors.forename: Xiao-Bai
authors.initials: XB
authors.lastname: Wang
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000493:pharmacokinetics*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007455:Iodine / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014283:Triiodobenzoic Acids / Q000493:pharmacokinetics*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007455:Iodine; C054871:ioversol
keywords: Dual-energy imaging; lung perfusion; multidetector CT; pulmonary embolism