title: Dual-source CT in heart transplant recipients: quantification of global left ventricular function and mass.
abstract: OBJECTIVE
  To evaluate reliability of global left ventricular (LV) function and mass quantification in heart transplant recipients undergoing cardiac dual-source computed tomography examinations by means of manual contour tracing and using a region-growing-based semiautomatic segmentation analysis software tool.
  
  
  METHODS
  Twenty-six consecutive heart transplant recipients undergoing cardiac dual-source computed tomography examinations with tube current modulation were included. Double-oblique short-axis 8-mm slice thickness multiphase image reconstructions were used for manual contouring and axial 0.75 mm slices were used for the semiautomated segmentation. LV ejection fraction, end-diastolic volume, end-systolic volume, stroke volume, cardiac output, and myocardial mass were assessed by both segmentation methods. Length of time needed for manual contour tracing and for the semiautomated software was recorded. Contrast-to-noise ratio was calculated in end-diastolic and end-systolic images.
  
  
  RESULTS
  No statistically significant differences were observed in LV functional parameters derived from semiautomatic contour detection algorithm as compared with manual contouring, with excellent agreement (concordance-correlation coefficient >or=0.80). The semiautomated contour detection algorithm overestimated LV mass (mean difference 12.84+/-3.39) (P<0.001). The evaluated software allowed to quantify LV parameters in a significantly shorter period of time (mean difference 201.68+/-121.98 s, P<0.001). Contrast-to-noise ratio in end-systole and end-diastole statistically differed (mean difference 5.29+/-2.94 Hounsfield units; P<0.01) but did not significantly hamper the semiautomated segmentation.
  
  
  CONCLUSIONS
  Objective quantification of LV volumes using the evaluated semiautomated segmentation software is precise, reproducible, and time effective.
authors.affiliation: Department of Radiology, Clínica Universitaria, Universidad de Navarra, Pamplona, Spain. bastarrika@unav.es
authors.forename: Gorka
authors.initials: G
authors.lastname: Bastarrika
authors.forename: Maria
authors.initials: M
authors.lastname: Arraiza
authors.forename: Carlo Nicola
authors.initials: CN
authors.lastname: De Cecco
authors.forename: Jordi
authors.initials: J
authors.lastname: Broncano
authors.forename: Stefano
authors.initials: S
authors.lastname: Mastrobuoni
authors.forename: Matias
authors.initials: M
authors.lastname: Ubilla
authors.forename: Jesus C
authors.initials: JC
authors.lastname: Pueyo
authors.forename: Gregorio
authors.initials: G
authors.lastname: Rábago
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage; D017023:Coronary Angiography; D004562:Electrocardiography; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012984:Software; D013318:Stroke Volume / Q000502:physiology; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol