title: Detection of pulmonary embolism using dual-energy computed tomography and correlation with cardiovascular measurements: a preliminary study.
abstract: BACKGROUND
  Detection of a suspected pulmonary embolism (PE) has been the focus of considerable research over the past few decades. Recently developed dual-source computed tomography (DSCT) scanners with dual-energy mode have been used to detect PE, but the studies on this topic are few.
  
  
  OBJECTIVE
  To assess the clinical value of dual-source, dual-energy CT (DECT) for the diagnosis of suspected PE and to correlate with cardiovascular measurements.
  
  
  METHODS
  31 patients with suspected PE underwent contrast-enhanced DSCT scanning with dual-energy mode. Dedicated software for lung perfusion blood volume (PBV) was used in postprocessing. The numbers and locations of PE in PBV images and CT pulmonary angiography (CTPA) were recorded. Sensitivity and specificity were measured, comparing to CTPA as a standard of reference. The relationship between range of iodine mapping abnormality in PBV images and cardiovascular measurements was analyzed.
  
  
  RESULTS
  33 DECT scans were performed in 31 patients. Seventeen patients had PE, while 14 patients had negative results. Filling defects were detected in pulmonary arteries in 44 pulmonary lobar and 99 segmental arteries. Compared to CTPA as a standard of reference, sensitivity and specificity of PBV images were 93.8% and 93.3% on a per-patient basis, 93.2% and 94.7% on a per-lobe basis, and 76.1% and 97.6% on a per-segment basis, respectively. Spearman correlation test showed good positive correlation between the right ventricle (RV)/left ventricle (LV) diameter ratio and pulmonary lobes with emboli for PBV images (R=0.663; P=0.004).
  
  
  CONCLUSIONS
  DECT can provide morphological and functional information of the whole lung in a single contrast-enhanced acquisition; the perfusion defects visualized in PBV images appear to have a positive relationship with the patients' right heart dysfunction.
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu Province, China.
authors.forename: Long Jiang
authors.initials: LJ
authors.lastname: Zhang
authors.forename: Gui Fen
authors.initials: GF
authors.lastname: Yang
authors.forename: Yan E
authors.initials: YE
authors.lastname: Zhao
authors.forename: Chang Sheng
authors.initials: CS
authors.lastname: Zhou
authors.forename: Guang Ming
authors.initials: GM
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000792:Angiography; D003287:Contrast Media; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000000981:diagnostic imaging; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide