- Meeting abstract
- Open Access
1100 Phase contrast imaging: a novel way of assessing left ventricular diastolic function
© Kumar et al; licensee BioMed Central Ltd. 2008
- Published: 22 October 2008
- Diastolic Dysfunction
- Diastolic Function
- Siemens Medical Solution
- Left Ventricular Diastolic Dysfunction
- Left Ventricular Diastolic Function
Diastolic left ventricular (LV) intracavitary blood flow is recognized to be complex and involves multiple streamlines oriented in different directions. Phase contrast magnetic resonance imaging (PC-MRI) with its 3-dimensional evaluation of proton phase shifts, is well-suited and validated for hemodynamic assessment of cardiac output, shunt ratio and valvular function. We hypothesized that PC-MRI could be used to assess LV diastolic intracavitary blood flow.
15 patients with varying degrees of LV diastolic dysfunction who had a recent 2-D Doppler echocardiogram underwent PC-MRI evaluation. Participants were imaged in the supine position with a 1.5-T whole-body clinical scanner (Avanto, Siemens Medical Solutions, Erlangen, Germany). Velocity in 3 separate directions (through-plane, in-plane anterior-posterior, and in-plane right-to-left) were assessed in the 4-chamber view using a time to repeat (TR) of 92.45 ms, a time to echo (TE) of 2.88, a flip angle of 30, and a velocity-encoding (VENC) ranging from 100 to 150 cm/s.
Images were then analyzed off-line using a 4D flow program (Siemens Medical Solutions, Philadelphia, PA) which allowed color-coded vector imaging of blood flow streamlines were assessed throughout diastole. The distance of intact flow propagation was measured from the mitral annulus to the end of the jetstream. The fractional propagation was the ratio of this distance to the entire length of the left ventricle. Echo Doppler analyses of diastolic function were based on mitral annular velocities (E', in cm/s) and mitral inflow pattern (relative peak E and A velocities in cm/s), and patients were graded as either normal (normal E velocity and normal E'), mildly impaired (low E velocity and low E') or severely impaired (high E velocity and low E'). These two methods of diastolic assessment were then compared among groups using the 2-tailed unpaired t-test.
Doppler and MRI-PC comparison between patients with varying degrees of diastolic dysfunction
Echo Doppler Peak E velocity/peak A velocity (mean ± SD)
Echo Doppler peak E velocity/peak annular tissue Doppler velocity (mean ± SD)
Phase contrast MRI fractional propagation (mean ± SD)
1.81 ± 0.97
7.66 ± 1.40
1 ± 0
Mild Diastolic Impairment
1.09 ± 0.41
8.50 ± 2.11
0.58 ± 0.06*
Severe Diastolic Impairment
2.36 ± 1.15**
14.79 ± 2.71*, **
0.59 ± 0.21*
Based on this data, phase contrast analysis can potentially differentiate between normal and abnormal diastolic function, specifically with respect to flow propagation throughout the ventricle. Further studies are warranted that involve a greater number of patients and that attempt to differentiate between degrees of diastolic dysfunction.
This article is published under license to BioMed Central Ltd.