Diffusion Tractography of the Entire Left Ventricle by Using Free-breathing Accelerated Simultaneous Multisection Imaging.
Purpose To develop a clinically feasible whole-heart free-breathing diffusion-tensor (DT) magnetic resonance (MR) imaging approach with an imaging time of approximately 15 minutes to enable three-dimensional (3D) tractography. Materials and Methods The study was compliant with HIPAA and the institutional review board and required written consent from the participants. DT imaging was performed in seven healthy volunteers and three patients with pulmonary hypertension by using a stimulated echo sequence. Twelve contiguous short-axis sections and six four-chamber sections that covered the entire left ventricle were acquired by using simultaneous multisection (SMS) excitation with a blipped-controlled aliasing in parallel imaging readout. Rate 2 and rate 3 SMS excitation was defined as two and three times accelerated in the section axis, respectively. Breath-hold and free-breathing images with and without SMS acceleration were acquired. Diffusion-encoding directions were acquired sequentially, spatiotemporally registered, and retrospectively selected by using an entropy-based approach. Myofiber helix angle, mean diffusivity, fractional anisotropy, and 3D tractograms were analyzed by using paired t tests and analysis of variance. Results No significant differences (P > .63) were seen between breath-hold rate 3 SMS and free-breathing rate 2 SMS excitation in transmural myofiber helix angle, mean diffusivity (mean ± standard deviation, [0.89 ± 0.09] × 10-3mm2/sec vs [0.9 ± 0.09] × 10-3mm2/sec), or fractional anisotropy (0.43 ± 0.05 vs 0.42 ± 0.06). Three-dimensional tractograms of the left ventricle with no SMS and rate 2 and rate 3 SMS excitation were qualitatively similar. Conclusion Free-breathing DT imaging of the entire human heart can be performed in approximately 15 minutes without section gaps by using SMS excitation with a blipped-controlled aliasing in parallel imaging readout, followed by spatiotemporal registration and entropy-based retrospective image selection. This method may lead to clinical translation of whole-heart DT imaging, enabling broad application in patients with cardiac disease.©RSNA, 2016 Online supplemental material is available for this article.
From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (C.M., T.G.R., S.F.C., K.S., D.E.S.), and Cardiovascular Research Center, Cardiology Division (D.E.S.), Massachusetts General Hospital, Harvard Medical School, 149 13th St, Charlestown, MA 02129; Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil (M.P.J.); and Siemens Healthcare, Charlestown, Mass (H.B.).
Choukri
C
Mekkaoui
From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (C.M., T.G.R., S.F.C., K.S., D.E.S.), and Cardiovascular Research Center, Cardiology Division (D.E.S.), Massachusetts General Hospital, Harvard Medical School, 149 13th St, Charlestown, MA 02129; Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil (M.P.J.); and Siemens Healthcare, Charlestown, Mass (H.B.).
Timothy G
TG
Reese
From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (C.M., T.G.R., S.F.C., K.S., D.E.S.), and Cardiovascular Research Center, Cardiology Division (D.E.S.), Massachusetts General Hospital, Harvard Medical School, 149 13th St, Charlestown, MA 02129; Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil (M.P.J.); and Siemens Healthcare, Charlestown, Mass (H.B.).
Marcel P
MP
Jackowski
From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (C.M., T.G.R., S.F.C., K.S., D.E.S.), and Cardiovascular Research Center, Cardiology Division (D.E.S.), Massachusetts General Hospital, Harvard Medical School, 149 13th St, Charlestown, MA 02129; Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil (M.P.J.); and Siemens Healthcare, Charlestown, Mass (H.B.).
Stephen F
SF
Cauley
From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (C.M., T.G.R., S.F.C., K.S., D.E.S.), and Cardiovascular Research Center, Cardiology Division (D.E.S.), Massachusetts General Hospital, Harvard Medical School, 149 13th St, Charlestown, MA 02129; Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil (M.P.J.); and Siemens Healthcare, Charlestown, Mass (H.B.).
Kawin
K
Setsompop
From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (C.M., T.G.R., S.F.C., K.S., D.E.S.), and Cardiovascular Research Center, Cardiology Division (D.E.S.), Massachusetts General Hospital, Harvard Medical School, 149 13th St, Charlestown, MA 02129; Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil (M.P.J.); and Siemens Healthcare, Charlestown, Mass (H.B.).
Himanshu
H
Bhat
From the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (C.M., T.G.R., S.F.C., K.S., D.E.S.), and Cardiovascular Research Center, Cardiology Division (D.E.S.), Massachusetts General Hospital, Harvard Medical School, 149 13th St, Charlestown, MA 02129; Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil (M.P.J.); and Siemens Healthcare, Charlestown, Mass (H.B.).
David E
DE
Sosnovik
D056324:Diffusion Tensor Imaging / Q000379:methods*; D005240:Feasibility Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012119:Respiration
Am J Physiol. 1998 Dec;275(6 Pt 2):H2308-18
9843833
J Digit Imaging. 2008 Sep;21(3):338-47
17577596
Circ Res. 2011 Jan 7;108(1):113-28
21212393
Magn Reson Med. 2002 Jun;47(6):1202-10
12111967
Magn Reson Med. 2015 Mar;73(3):995-1004
24659571
Circ Cardiovasc Imaging. 2009 Jan;2(1):32-40, 6 p following 40
19808562
Magn Reson Med. 1995 Dec;34(6):786-91
8598805
Magn Reson Med. 2016 Apr;75(4):1669-76
26033456
Magn Reson Med. 1996 Dec;36(6):893-906
8946355
Ann Thorac Surg. 2014 Oct;98(4):1355-62
25130075
Circulation. 2014 Apr 29;129(17):1731-41
24619466
Magn Reson Med. 2004 Sep;52(3):590-7
15334579
Magn Reson Med. 2012 May;67(5):1210-24
21858868
Magn Reson Med. 1999 Nov;42(5):952-62
10542355
Magn Reson Med. 2013 Aug;70(2):454-65
23001828
J Cardiovasc Magn Reson. 2012 Oct 12;14:70
23061749
Magn Reson Med. 2007 Feb;57(2):331-7
17260376
Magn Reson Med. 2008 Jun;59(6):1431-9
18506789
Magn Reson Med. 1994 Sep;32(3):423-8
7984077
Magn Reson Med. 1999 Aug;42(2):393-403
10440965
PLoS One. 2014 Sep 05;9(9):e107159
25191900
Neuroimage. 2012 Oct 15;63(1):569-80
22732564
Magn Reson Med. 2014 Nov;72(5):1257-67
24259113
NMR Biomed. 1995 Nov-Dec;8(7-8):333-44
8739270
Magn Reson Med. 2015 Aug;74(2):420-30
25154715