POSTER PRESENTATION Open Access Coronary vessel wall MRI ...€¦ · POSTER PRESENTATION Open...
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POSTER PRESENTATION Open Access Coronary vessel wall MRI at 3.0 T using Time-Resolved Acquisition of Phase-Sensitive DIR (TRAPD): initial results in patients with risk factors for coronary artery disease Khaled Z Abd-Elmoniem 1* , Ahmed Gharib 1 , Roderic I Pettigrew 1,2 From 16th Annual SCMR Scientific Sessions San Francisco, CA, USA. 31 January - 3 February 2013 Background Technical challenges still hinder coronary wall imaging for routine clinical utilization. These challenges include image degradation due to aperiodic intrinsic cardiac and chest wall respiratory motions and residual motion due to uncompensated heart-rate variability. The purpose of this study was to 1) develop a time-resolved acquisition of phase-sensitive DIR coronary vessel wall MRI techni- que that overcomes the loss of the orthogonality due to uncompensated residual motions, 2) investigate the associated improvement in coronary wall imaging suc- cess rate when compared to that of single image coron- ary wall imaging, and to 3) assess the ability of the technique to show a difference in vessel wall thickness between healthy subjects and subjects with risk factors for coronary artery disease (CAD). Methods A 3T single-slice time-resolved free-breathing PS-DIR (TRAPD) coronary vessel wall imaging sequence was implemented, validated in a flow phantom. The coron- ary arterial wall, using 3 to 5 cine-image measurements, were obtained of 26 subjects with at least one Framing- ham CAD risk factors and 12 healthy subjects without history or risk factors for CAD. Image quality was scored and assessed, wall thickness was automatically measured, and qualitative and quantitative comparisons were made between TRAPD and conventional single- image wall measurements. Results Time resolved coronary vessel wall imaging using TRAPD successfully restored the negative polarity of lumen signal and enhanced lumen-wall contrast in the cine images in flow-phantom (Figure 1), and in both normal and subjects with coronary risk factors (Figure 2). The acquisition and utilization of the additional frames increased the cumula- tive success rate of acquiring at least one adequate-quality image from 76% in single-image acquisitions to over 90% when five frames were acquired. Utilizing multiple conse- cutive frames in calculations achieved more separation between the normals’ and patients’ mean wall thickness values, and with more precision demonstrated by a nar- rower standard deviation. The difference in vessel wall thickness between the two subject groups was statistically significant (p<0.05) when using TRAPD (1.07 mm vs. 1.46 mm; 36% increase) compared to single-frame DIR imaging (1.24 mm vs. 1.55 mm; 25% increase). Conclusions Fast time-resolved phase-sensitive DIR imaging was implemented to improve coronary arterial wall imaging by increasing the success rate of obtaining good to excellent quality images inclusive of slice vessel ortho- gonality (i.e., slices orthogonal to longitudinal axis of the vessel). This has resulted in vessel wall thickness mea- surements that show a more distinct difference between normal and patient populations. Funding National Institutes of Health. 1 National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA Full list of author information is available at the end of the article Abd-Elmoniem et al. Journal of Cardiovascular Magnetic Resonance 2013, 15(Suppl 1):P26 http://www.jcmr-online.com/content/15/S1/P26 © 2013 Abd-Elmoniem et al; licensee 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.
Transcript of POSTER PRESENTATION Open Access Coronary vessel wall MRI ...€¦ · POSTER PRESENTATION Open...
POSTER PRESENTATION Open Access
Coronary vessel wall MRI at 3.0 T usingTime-Resolved Acquisition of Phase-Sensitive DIR(TRAPD): initial results in patients with risk factorsfor coronary artery diseaseKhaled Z Abd-Elmoniem1*, Ahmed Gharib1, Roderic I Pettigrew1,2
From 16th Annual SCMR Scientific SessionsSan Francisco, CA, USA. 31 January - 3 February 2013
BackgroundTechnical challenges still hinder coronary wall imagingfor routine clinical utilization. These challenges includeimage degradation due to aperiodic intrinsic cardiac andchest wall respiratory motions and residual motion dueto uncompensated heart-rate variability. The purpose ofthis study was to 1) develop a time-resolved acquisitionof phase-sensitive DIR coronary vessel wall MRI techni-que that overcomes the loss of the orthogonality due touncompensated residual motions, 2) investigate theassociated improvement in coronary wall imaging suc-cess rate when compared to that of single image coron-ary wall imaging, and to 3) assess the ability of thetechnique to show a difference in vessel wall thicknessbetween healthy subjects and subjects with risk factorsfor coronary artery disease (CAD).
MethodsA 3T single-slice time-resolved free-breathing PS-DIR(TRAPD) coronary vessel wall imaging sequence wasimplemented, validated in a flow phantom. The coron-ary arterial wall, using 3 to 5 cine-image measurements,were obtained of 26 subjects with at least one Framing-ham CAD risk factors and 12 healthy subjects withouthistory or risk factors for CAD. Image quality wasscored and assessed, wall thickness was automaticallymeasured, and qualitative and quantitative comparisonswere made between TRAPD and conventional single-image wall measurements.
ResultsTime resolved coronary vessel wall imaging using TRAPDsuccessfully restored the negative polarity of lumen signaland enhanced lumen-wall contrast in the cine images inflow-phantom (Figure 1), and in both normal and subjectswith coronary risk factors (Figure 2). The acquisition andutilization of the additional frames increased the cumula-tive success rate of acquiring at least one adequate-qualityimage from 76% in single-image acquisitions to over 90%when five frames were acquired. Utilizing multiple conse-cutive frames in calculations achieved more separationbetween the normals’ and patients’ mean wall thicknessvalues, and with more precision demonstrated by a nar-rower standard deviation. The difference in vessel wallthickness between the two subject groups was statisticallysignificant (p<0.05) when using TRAPD (1.07 mm vs. 1.46mm; 36% increase) compared to single-frame DIR imaging(1.24 mm vs. 1.55 mm; 25% increase).
ConclusionsFast time-resolved phase-sensitive DIR imaging wasimplemented to improve coronary arterial wall imagingby increasing the success rate of obtaining good toexcellent quality images inclusive of slice vessel ortho-gonality (i.e., slices orthogonal to longitudinal axis of thevessel). This has resulted in vessel wall thickness mea-surements that show a more distinct difference betweennormal and patient populations.
FundingNational Institutes of Health.
1National Institute of Diabetes and Digestive and Kidney Diseases, NationalInstitutes of Health, Bethesda, MD, USAFull list of author information is available at the end of the article
Abd-Elmoniem et al. Journal of Cardiovascular MagneticResonance 2013, 15(Suppl 1):P26http://www.jcmr-online.com/content/15/S1/P26
© 2013 Abd-Elmoniem 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.
Figure 1 TRAPD Phantom signal intensity and contrast using incremental TI ranging from 25 ms to 250 ms, a) modulus (DIR), phase, and TRAPDsigned-magnitude images, b) signal intensity inside and outside the lumen, c) DIR and TRAPD tissue-lumen contrasts.
Figure 2 a) TRAPD (top row) and conventional DIR modulus images (second row) of a healthy subject. White circles denote the frames withgood or excellent quality. Filled circle denotes the frame with the thinnest wall thickness measurement. b) Line intensity profiles across thecoronary vessel wall and lumen at different time frames using TRAPD (solid lines) and DIR (broken lines).
Abd-Elmoniem et al. Journal of Cardiovascular MagneticResonance 2013, 15(Suppl 1):P26http://www.jcmr-online.com/content/15/S1/P26
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Author details1National Institute of Diabetes and Digestive and Kidney Diseases, NationalInstitutes of Health, Bethesda, MD, USA. 2National Institute of BiomedicalImaging and Bioengineering, National Institutes of Health, Bethesda, MD,USA.
Published: 30 January 2013
doi:10.1186/1532-429X-15-S1-P26Cite this article as: Abd-Elmoniem et al.: Coronary vessel wall MRI at 3.0T using Time-Resolved Acquisition of Phase-Sensitive DIR (TRAPD):initial results in patients with risk factors for coronary artery disease.Journal of Cardiovascular Magnetic Resonance 2013 15(Suppl 1):P26.
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Abd-Elmoniem et al. Journal of Cardiovascular MagneticResonance 2013, 15(Suppl 1):P26http://www.jcmr-online.com/content/15/S1/P26
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