Can a single phase contrast aortic flow acquisition be used to define a surrogate marker of cardiac index

-12.88 -6.9 SV were successfully estimated using cardiac and aortic studies. In the latter case, no failure of the automated procedure was reported in the studied population. Using these values and heart rate (mean value 68 bpm, range 34-102) cardiac output (CO) was computed. Finally cardiac index (Figure 2) was derived by introducing the body surface area (mean value: 1.83 m 2 , range 1.37- 2.23). Linear regression between the cardiac and aortic series of values showed a high correlation: r=0.80 for VE, r=0.78 for CO and r=0.76 for CI. However, the VEa, COa, and CIa values derived from PC aortic sequences were clearly underestimated when compared to the same values derived from cardiac images. For the three indices, the underestimation ratio was estimated to be 15%.