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Integrated quantitative first-pass cardiac perfusion MRI protocol
Journal of Cardiovascular Magnetic Resonance volume 13, Article number: P60 (2011)
The proposed contrast-enhanced first-pass perfusion cardiovascular MR (CMR) protocol integrates some recent technical MRI advances towards quantitative analysis of perfusion CMR images: fast multi-slice pulse sequence , robust saturation pulse , accurate dedicated AIF imaging , signal-to-concentration modeling , and higher SNR at 3T.
To evaluate an integrated first-pass perfusion cardiovascular MR (CMR) protocol designed to determine absolute contrast-agent concentrations in blood and tissues.
A multi-slice saturation recovery (SR) pulse sequence with sequential SR time delays (TD) after a non-selective saturation pulse  was implemented at 3T (Fig.1). The rationale for this acquisition scheme was to acquire a dedicated arterial input function (AIF) image with a short TD (50ms) in the aortic root and short-axis myocardial images with longer TD values (~150-400ms), to allow for the different amounts of T1 shortening expected in blood and wall. First-pass perfusion CMR was performed in 7 volunteers (0.05mmol/kg, Gd-DTPA). A signal-to-concentration model was applied to calculate Gd-DTPA concentrations in blood and tissues [4, 5]. A proton density-weighted (PDw) image was acquired in the first heartbeat, without the saturation pulse, in order to normalize the image signal, and obtain a theoretical signal-to-T1 relationship based on Bloch equation in the center of k-space. Gd-DTPA concentrations were calculated assuming: fast water exchange condition , longitudinal relaxivity r1=3.8L.mmol-1.s-1, and baseline T1 measured with a multi-point SR fit. TurboFLASH imaging parameters included: FOV=350mm×315mm, slice thickness=8mm, matrix=160×144, in-plane resolution=2.2mm×2.2mm, TE/TR=1.2/2.4ms, flip angle 10°, temporal resolution=114ms, tSENSEx3, centric k-space trajectory, and receiver bandwidth=1008Hz/pix. Total image acquisition time was 523ms for the acquisition of 4 slices, namely aortic root and SA base, mid, and apex levels, with respective TD values 50-164-278-393ms. Contours for the blood and left ventricle were drawn manually, and the myocardium was divided into 6 (base-mid) or 4 (apex) standard segments.
Representative images at peak contrast in blood and myocardium are shown Fig.2, along with representative AIF and myocardial segment time-responses. The peak blood signal was not clipped in the short TD=50ms AIF images. Normalized signal in the myocardium increased along with TD; however similar [Gd-DTPA] were measured in all 3 short-axis images. First-pass perfusion peak Gd-DTPA concentrations were 3.95±0.080, 0.26±0.07mM in the blood and myocardium, respectively.
The proposed integrated first-pass perfusion CMR protocol at 3T produced AIF and myocardial wall Gd-DTPA concentrations consistent with previously published results. Future work includes evaluation of the integrated protocol in cardiac patients.
Nagel E: Circulation. 2003, 108: 432-437. 10.1161/01.CIR.0000080915.35024.A9.
Kim D: Magn Reson Med. 2008, 62: 1368-1378. 10.1002/mrm.22140.
Kim D, Axel LJ: Magn Reson Imaging. 2006, 23: 81-86. 10.1002/jmri.20471.
Cernicau A, Axel L: Acad Radiol. 2006, 13: 686-693. 10.1016/j.acra.2006.02.040.
Breton E: SCMR. 2010
Dobahue KM: J Magn Reson Imaging. 1997, 7: 102-110. 10.1002/jmri.1880070114.
Rohrer M: invest Radiol. 2005, 40: 715-724. 10.1097/01.rli.0000184756.66360.d3.
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Breton, E., Kim, D., Chung, S. et al. Integrated quantitative first-pass cardiac perfusion MRI protocol. J Cardiovasc Magn Reson 13, P60 (2011). https://doi.org/10.1186/1532-429X-13-S1-P60
- Arterial Input Function
- Saturation Pulse
- Saturation Recovery
- Short Time Delay
- Sequential Saturation Recovery