- Poster presentation
- Open Access
Volumetric motion quantification by 3D velocity encoded MRI
© Lutz et al; licensee BioMed Central Ltd. 2012
- Published: 1 February 2012
- Cardiac Resynchronization Therapy
- Philips Healthcare
- Black Blood
- Cardiac Segment
- Segmented Gradient
It is objective to show the feasibility of volumetric velocity-encoded MRI (3D-TPM) to derive velocity based motion quantification parameters.
About 30% of patients treated with cardiac resynchronization therapy (CRT) do not benefit from the procedure. The introduction of quantitative parameters for selection of patients appears mandatory. However, parameters based on 2D imaging techniques may be less reproducible caused by rapid changes of the motion pattern along the cardiac axis.
12 volunteers (26±7 years) and 2 patients (46, DCM/29, LBBB) were investigated at a 3T whole body MR scanner (Achieva, Philips) with a 32 channel cardiac coil. A 3D black blood velocity encoded navigated segmented gradient echo sequence (3D-TPM) was applied for whole heart coverage. The acquisition parameters were: FOV=3802mm2, isotropic resolution of 3x3x3mm3, FOV in through-plane direction =63mm in healthy volunteers (this FOV was increased in patients due to their enlarged heart corresponding to the distance between basis and apex), acquisition matrix =128x124, TR/TE=7.1ms/4.9ms, flip angle =15°, SENSE =4, nominal scan duration =15:30 minutes, 3 k-lines per segment, phase interval =37.3ms and 25 cardiac phases for 60bpm. The acquisition of the whole heart data was split into 3 chunks to ensure sufficient black blood contrast.
From the 3D-TPM data, the following parameters were evaluated: longitudinal and radial standard deviation of time to peak systolic and diastolic velocities SD(TTPl,sys), SD(TTPl,dias), SD(TTPr,sys), SD(TTPr,dias), the mean radial, circumferential and longitudinal asynchrony correlation coefficient over all cardiac segments (ACC), the longitudinal and radial velocity range Δvl = vl,max-vl,min, Δvr = vr,max-vr,min and the new parameter temporal uniformity of velocity (TUV) in radial, longitudinal and circumferential direction, which was defined analogously to the temporal uniformity of strain defined in [3, 4].
Velocity based motion parameters evaluated for all volunteers (mean ± standard deviation) and for investigated patients.
mean Δvl [cm/s]
mean Δvr [cm/s]
It is feasible to determine motion quantification parameters based on 3D velocity data. Huge differences could be observed between asynchronous patients and volunteers. A study including more patients is necessary to decide whether 3D -TPM data may in future distinguish between responders and non-responders to CRT.
AL and VR have a research agreement with Philips Healthcare. PE is employed by Philips Healthcare.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.