title: Assessment of the regurgitant orifice area in aortic regurgitation with dual-source CT: Comparison with cardiovascular magnetic resonance.
abstract: BACKGROUND
  Regurgitant orifice area (ROA) measurements by cardiac CT have not been compared with a quantitative classification of aortic regurgitation (AR) severity based on regurgitant fraction by phase-contrast cardiovascular magnetic resonance (PC-CMR).
  
  
  OBJECTIVE
  To compare ROA using dual-source CT (DSCT) with the grade of AR using PC-CMR for obtaining the cutoff values of the ROA allowing for grading of AR severity.
  
  
  METHODS
  We retrospectively enrolled 208 patients (81 women, mean age 53.3 ± 14.4 years) with AR who underwent DSCT and CMR. DSCT data sets were reconstructed in 10% steps from 0% to 90% of the R-R interval to measure ROA. Grades of AR were determined by regurgitant fraction using PC-CMR. Receiver operating characteristic curves were calculated to differentiate between grades of AR and ROA.
  
  
  RESULTS
  Sixty-three patients with mild AR, 80 with moderate AR, and 65 with severe AR by PC-CMR were enrolled. Quantification of the ROA by DSCT (mean, 27 ± 21 mm2) was significantly correlated with the grade of AR by PC-CMR (r = 0.83). In the receiver operating characteristic analysis, discrimination (mild vs moderate and moderate vs severe) among grades of AR with DSCT was accurate when cutoff ROAs of 15 mm2 and 23 mm2 in comparison with PC-CMR were used.
  
  
  CONCLUSIONS
  The cutoff values of the ROA by DSCT allow for grading of AR severity determined by PC-CMR but are lower than those previously published, using transthoracic echocardiography as the reference standard. A multicenter study is necessary with a wide range of population for obtaining cutoff ROAs.
authors.affiliation: Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, 4-12 Hwayang-dong, Gwangjin-gu, Seoul 143-729, Korea. Electronic address: ksm9723@yahoo.co.kr.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Ko
authors.affiliation: Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, 4-12 Hwayang-dong, Gwangjin-gu, Seoul 143-729, Korea.
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Thoracic surgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Je Kyoun
authors.initials: JK
authors.lastname: Shin
authors.affiliation: Department of Thoracic surgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Jun Suk
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000473:pathology*; D001022:Aortic Valve Insufficiency / Q000175:diagnosis*; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: Aortic regurgitation; Cardiovascular magnetic resonance; Computed tomography; Echocardiography; Planimetry