Quantitative evaluation of the severity of aortic regurgitation by cine magnetic resonance imaging

In cine magnetic resonance imaging (MRI) the severity of aortic regurgitation (AR) should correlate with the degree of the low-intensity signal (LS). To evaluate the usefulness for identifying the severity of AR, the authors measured the length, area, and volume of the maximum AR-LS and the left ventricular end-diastole (LVED). They subsequently calculated the ratio (% AR-LS) of the maximum AR-LS to the LVED in 23 patients with AR (mild=8, moderate=6, severe=9). Their findings on cine MRI were compared with their angiographic findings. The more severe the AR, the greater the increase in % AR-LS length, area, and volume. From these findings, they assessed quantitatively the severity of AR by using cine MRI. The % AR-LS length in AR of each severity was mild: <50%, moderate: 50–64%, and severe: ≥ 65% (accuracy 73.9%). The % AR-LS area in AR of each severity was mild: <20%, moderate: 20–29%, and severe ≥30% (accuracy 78.3%). The % AR-LS volume in AR of each severity was mild: <6.0%, moderate: 6.0–9.9%, and severe: ≥ 10% (accuracy 69.6%) They suggest that the % AR-LS area is more important than the % AR-LS length and volume in evaluating the severity of AR. Thus, cine MRI is a useful noninvasive method for the quantitative evaluation of the severity of AR.