Magnetic Resonance Elastography of Regional Aortic Mechanics and True- and False-Lumen Stiffness in Aortic Dissection: A Feasibility Study
- 1University of Rochester
Abstract
ObjectiveRegional aortic mechanics and the mechanical environments of the true and false lumens are not represented by maximal diameter alone. We evaluated whether magnetic resonance elastography (MRE) could provide paired descending thoracic and abdominal aorta stiffness estimates and separate true- and false-lumen estimates in thoracic aortic dissection.
MethodsWe acquired 60-Hz descending thoracic and abdominal aortic MRE data in 10 healthy subjects and in 2 patients with chronic type B aortic dissections. Three motion-encoding directions and four temporal offsets were reduced to first-harmonic complex wave fields. After directional filtering, we traced a curved centerline through the aortic mask. Local spatial frequency was estimated along arc length and converted to effective shear stiffness. The primary regional outcome was the mean effective stiffness over the central 20%-90% of the path from the quality-ranked slice in each region. In dissection, the whole-aorta mask and flap were defined on a registered sagittal scout; a vascular surgeon assigned the true and false lumens, and separate, manually centered lumen paths followed one union-mask phase correction and unwrapping step. We compared regional values with paired tests.
ResultsAll 10 regional datasets and all 56 available slices were processed without failure. The 10 healthy volunteers (mean age, 26.6 {+/-} 4.6 years; 6 men) had descending thoracic stiffness of 15.43 {+/-} 3.30 kPa and abdominal stiffness of 19.20 {+/-} 3.14 kPa. The mean thoracic-minus-abdominal difference was -3.77 {+/-} 3.40 kPa (95% confidence interval, -6.20 to -1.34 kPa; paired t-test, P=.007; exact Wilcoxon signed-rank test, P=.010). Eight participants had a higher abdominal value, and two had a higher thoracic value. In Subject A with a chronic aortic dissection, slice-averaged true- and false-lumen stiffness was 21.62 and 19.07 kPa, respectively (false-minus-true, -2.54 kPa; absolute percentage difference, 12.5%). In Subject B with a chronic aortic dissection, corresponding values were 12.17 and 17.40 kPa (false-minus-true, +5.22 kPa; 35.3%).
ConclusionsWe demonstrated the feasibility of MRE to provide paired regional analysis of the aorta in healthy people and to separate stiffness profiles of the true and false lumens in Type B thoracic dissection cases. Abdominal effective stiffness exceeded descending thoracic stiffness in the volunteer cohort. Opposite true- and false-lumen contrast in the two subjects with chronic Tye B aortic dissections demonstrates measurement feasibility but does not establish a consistent compartment pattern, disease threshold, or intrinsic wall material property.
Clinical RelevanceSurveillance of aortic disease is primarily anatomic, although expansion and rupture are mechanical processes. A regional MRE measurement may complement anatomic analyses by localizing wave-propagation behavior to a specific aortic segment or dissection lumen. The present study establishes the feasibility of noninvasive measurement of stiffness in a true and false lumen of dissected aorta.
HighlightsO_LILocal-frequency magnetic resonance elastography (MRE) yielded paired abdominal and descending thoracic effective-stiffness estimates in all 10 volunteers. C_LIO_LIAbdominal effective stiffness exceeded descending thoracic effective stiffness in this young feasibility cohort. C_LIO_LITrue and false-lumen stiffness contrast was measurable in both dissection cases, but its direction differed between cases. C_LIO_LIThe results show the potential of MRE to monitor aortic diseases such as dissection-associated aneurysms and abdominal and thoracic aneurysms. C_LI
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BibTeX
@misc{hirad2026magnetic,
title = {{Magnetic Resonance Elastography of Regional Aortic Mechanics and True- and False-Lumen Stiffness in Aortic Dissection: A Feasibility Study}},
author = {A. A. Hirad and H. Dong and M. Nanjappa and B. Kedwai and K. Thompson and J. Kruger and J. Chen and A. Kolipaka and D. Mix},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.09.26362667},
url = {https://www.medrxiv.org/content/10.64898/2026.09.09.26362667v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Magnetic Resonance Elastography of Regional Aortic Mechanics and True- and False-Lumen Stiffness in Aortic Dissection: A Feasibility Study
AU - A. A. Hirad
AU - H. Dong
AU - M. Nanjappa
AU - B. Kedwai
AU - K. Thompson
AU - J. Kruger
AU - J. Chen
AU - A. Kolipaka
AU - D. Mix
PY - 2026
DA - 2026/09/09
PB - medRxiv
DO - 10.64898/2026.09.09.26362667
UR - https://www.medrxiv.org/content/10.64898/2026.09.09.26362667v1
AB - ObjectiveRegional aortic mechanics and the mechanical environments of the true and false lumens are not represented by maximal diameter alone. We evaluated whether magnetic resonance elastography (MRE) could provide paired descending thoracic and abdominal aorta stiffness estimates and separate true- and false-lumen estimates in thoracic aortic dissection. MethodsWe acquired 60-Hz descending thoracic and abdominal aortic MRE data in 10 healthy subjects and in 2 patients with chronic type B aortic dissections. Three motion-encoding directions and four temporal offsets were reduced to first-harmonic complex wave fields. After directional filtering, we traced a curved centerline through the aortic mask. Local spatial frequency was estimated along arc length and converted to effective shear stiffness. The primary regional outcome was the mean effective stiffness over the central 20%-90% of the path from the quality-ranked slice in each region. In dissection, the whole-aorta mask and flap were defined on a registered sagittal scout; a vascular surgeon assigned the true and false lumens, and separate, manually centered lumen paths followed one union-mask phase correction and unwrapping step. We compared regional values with paired tests. ResultsAll 10 regional datasets and all 56 available slices were processed without failure. The 10 healthy volunteers (mean age, 26.6 {+/-} 4.6 years; 6 men) had descending thoracic stiffness of 15.43 {+/-} 3.30 kPa and abdominal stiffness of 19.20 {+/-} 3.14 kPa. The mean thoracic-minus-abdominal difference was -3.77 {+/-} 3.40 kPa (95% confidence interval, -6.20 to -1.34 kPa; paired t-test, P=.007; exact Wilcoxon signed-rank test, P=.010). Eight participants had a higher abdominal value, and two had a higher thoracic value. In Subject A with a chronic aortic dissection, slice-averaged true- and false-lumen stiffness was 21.62 and 19.07 kPa, respectively (false-minus-true, -2.54 kPa; absolute percentage difference, 12.5%). In Subject B with a chronic aortic dissection, corresponding values were 12.17 and 17.40 kPa (false-minus-true, +5.22 kPa; 35.3%). ConclusionsWe demonstrated the feasibility of MRE to provide paired regional analysis of the aorta in healthy people and to separate stiffness profiles of the true and false lumens in Type B thoracic dissection cases. Abdominal effective stiffness exceeded descending thoracic stiffness in the volunteer cohort. Opposite true- and false-lumen contrast in the two subjects with chronic Tye B aortic dissections demonstrates measurement feasibility but does not establish a consistent compartment pattern, disease threshold, or intrinsic wall material property. Clinical RelevanceSurveillance of aortic disease is primarily anatomic, although expansion and rupture are mechanical processes. A regional MRE measurement may complement anatomic analyses by localizing wave-propagation behavior to a specific aortic segment or dissection lumen. The present study establishes the feasibility of noninvasive measurement of stiffness in a true and false lumen of dissected aorta. HighlightsO_LILocal-frequency magnetic resonance elastography (MRE) yielded paired abdominal and descending thoracic effective-stiffness estimates in all 10 volunteers. C_LIO_LIAbdominal effective stiffness exceeded descending thoracic effective stiffness in this young feasibility cohort. C_LIO_LITrue and false-lumen stiffness contrast was measurable in both dissection cases, but its direction differed between cases. C_LIO_LIThe results show the potential of MRE to monitor aortic diseases such as dissection-associated aneurysms and abdominal and thoracic aneurysms. C_LI
ER -