Kowalik, GT

Muthurangu, V

Steeden, JA

Taylor, A

English

UCL Discovery

WORKSHOP PRESENTATION Open AccessTissue phase mapping using breath-hold 4D PCMRJennifer A Steeden*, Grzegorz T Kowalik, Andrew Taylor, Vivek MuthuranguFrom 17th Annual SCMR Scientific SessionsNew Orleans, LA, USA. 16-19 January 2014BackgroundConventionally Tissue Phase Mapping (TPM) is carriedout in one 2D slice. 4D PCMR has not previously beenused for TPM due to long acquisition times. The pur-pose of this study was to develop a highly accelerated4D PCMR sequence to acquire TPM data across theentire left ventricle (LV), during a breath-hold.MethodsAn undersampled, prospectively triggered, stack-of-spirals,4D PCMR sequence was developed, and reconstructedusing SENSE-UNFOLD. A uniform-density spiral trajec-tory was used in kx-ky with 8 interleaves required tofill k-space, with acceleration of R = 4 (resulting in 2 spiralinterleaves acquired per kz position). In kz, 16 sliceswere used, with acceleration of R = 2, resulting in 9 kzpositions being acquired for each cardiac phase (calculatedas 16÷2 plus one to ensure that the middle kz position isalways acquired). The other sequence parameters were;TE/TR:4.0/14.4 ms, matrix size:160 × 160, FOV:500 × 500mm, slices:16, slice thickness:8 mm, venc(x/y/z):30/30/30 cm/s. This resulted in a temporal resolution of 57.5 ms,UCL Centre for Cardiovascular Imaging, London, UKFigure 1 Example data from a healthy volunteer. Top; peak S wave, bottom; peak E wave. a) 2D vector plots from the mid slice, b)Longitudinal velocity, c) Radial velocity, d) Tangential velocity. The colors represent the velocities, with reds representing shortening/contraction/clockwise rotation, and blues representing lengthening/expansion/counter-clockwise rotation.Steeden et al. Journal of Cardiovascular MagneticResonance 2014, 16(Suppl 1):W30http://www.jcmr-online.com/content/16/S1/W30© 2014 Steeden et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.a spatial resolution of 3.1 × 3.1 × 8 mm, and a scan time of16 heartbeats (breath-hold), plus 7.3 s for acquisition offully sampled coil sensitivity maps with 4NSAs (freebreathing, at the end of the TPM acquisition). This 4DPCMR TPM data was acquired in 5 healthy volunteers(4M:1F, mean age:38.6 ± 6.6 yrs), and 1 patient with mildLV dyssynchrony (F, 43.3 yrs). Data Analysis: Bulk motioncorrection was performed, before transformation of thevelocities to an internal polar coordinate system allowingmotion to be described in terms of contraction (usingradial velocities; Vr) and shortening (using longitudinalvelocities; Vz). Peak velocities in the S (systolic) and E(early diastolic) waves were measured for the longitudinaland radial velocities within the entire myocardium, at abasal, mid and apical slice.ResultsData was successfully acquired and analyzed in all subjects.Figure 1 shows the calculated velocity data in one subject.In the volunteers quantitatively, the longitudinal velocitiesin the base/mid/apical slices were 4.9 ± 1.2/3.5 ± 1.3/2.4 ±0.6 cm/s at the S wave, and -6.2 ± 1.3/-3.9 ± 1.4/-2.43 ±1.5 cm/s at the E wave. The radial velocities in the base/mid/apical slices were 2.2 ± 0.4/2.7 ± 0.2/2.1 ± 0.2 cm/s atthe S wave, and -2.5 ± 0.4/-3.1 ± 0.5/-2.9 ± 0.1 cm/s at theE wave. In the patient the longitudinal velocities in thebase/mid/apical slices were significantly lower at the Swave (1.1/1.0/1.4 cm/s). Furthermore, there was evidenceof dyssynchrony in early LV diastole as shown in Figure 2.ConclusionsWe have shown that using a novel spiral UNFOLDSENSE PCMR sequence it is possible to obtain 4D TPMdata in a breath hold. This sequence may have significantvalue in the assessment of LV dyssynchrony, particularlyin relation to resynchronization therapy.Published: 16 January 2014doi:10.1186/1532-429X-16-S1-W30Cite this article as: Steeden et al.: Tissue phase mapping using breath-hold 4D PCMR. Journal of Cardiovascular Magnetic Resonance 201416(Suppl 1):W30.Submit your next manuscript to BioMed Centraland take full advantage of: • Convenient online submission• Thorough peer review• No space constraints or color figure charges• Immediate publication on acceptance• Inclusion in PubMed, CAS, Scopus and Google Scholar• Research which is freely available for redistributionSubmit your manuscript at www.biomedcentral.com/submitFigure 2 Data from the patient showing an area of the septum with a subtle dyssynchrony during the E wave. a) Longitudinal velocity,b) Radial velocity, c) Tangential velocity.Steeden et al. Journal of Cardiovascular MagneticResonance 2014, 16(Suppl 1):W30http://www.jcmr-online.com/content/16/S1/W30Page 2 of 2

Tissue Phase Mapping Using Single Breath-Hold 4D PCMR

https://discovery.ucl.ac.uk/id/eprint/10060269/1/Steeden_1532-429X-16-S1-W30.pdf

Tissue Phase Mapping Using Single Breath-Hold 4D PCMR

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