Debbie Scandling

Georgeta Mihai

Jason Craft

Juliet Varghese

Orlando P Simonetti

Subha V Raman

Journal of Cardiovascular Magnetic Resonance

PubMed

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Integrated treadmill stress testing and MR relaxometry (T1, T2, T2*): response in healthy calf muscles

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POSTER PRESENTATION Open Access
Integrated treadmill stress testing and MR
relaxometry (T1, T2, T2*): response in healthy calf
muscles
Juliet Varghese1,2*, Debbie Scandling1, Jason Craft3, Subha V Raman1,3, Orlando P Simonetti1,4, Georgeta Mihai1,3
From 17th Annual SCMR Scientific Sessions
New Orleans, LA, USA. 16-19 January 2014
Background
Peripheral arterial disease (PAD) is accompanied by a com-
plex lower limb pathophysiology resulting in reduced func-
tional capacity and quality of life. We aim to characterize
the exercise recovery kinetics in the calf muscle of healthy
volunteers by combining treadmill exercise and magnetic
resonance (MR) relaxometry (T1, T2 and T2*), and to inves-
tigate their relation with age and treadmill exercise duration.
1Dorothy M Davis Heart and Lung Research Institute, Wexner Medical Center, The
Ohio State University, Columbus, Ohio, USA
Full list of author information is available at the end of the article
Figure 1 A. Time course of exercise induced changes in the left calf muscles of a 30 year old male volunteer. Axial T1 (top row), T2 (middle
row) and T2* (bottom row) maps acquired before exercise (Pre), immediately after exercise (Post 1), at ~20 minutes (Post 9) and at ~45
minutes (Post 18) are shown. B. Exercise-induced time course changes of mean T1 (a), mean T2 (b) and mean T2* values (c) of the four calf muscle
groups in 24 volunteers before (Pre) and after exercise (Post_1 to 18 - ~2:20 minute intervals). Graph in blue - TA, red - Sol, green - MG and purple - LG.
Varghese et al. Journal of Cardiovascular Magnetic
Resonance 2014, 16(Suppl 1):P68
http://www.jcmr-online.com/content/16/S1/P68
© 2014 Varghese 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. 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.
Methods
Twenty four healthy volunteers (age: 23-79 years,
12 males) performed Bruce treadmill stress test to at
least 81% of age-predicted maximum heart rate on an
MR-compatible treadmill adjacent to a 1.5T MRI sys-
tem. Single slice axial T1 (TR/TE/TI = 1200/1.1/125,
205, 285, 1325, 1405, 1485, 2525, 2605, 2685, 3885 ms,
FA = 35°, 1 NEX, 1.9 × 1.9 × 8 mm3, 1:02 min:s), T2
(TR/TET2p = 2500/0, 24, 36, 48, 60 ms, FA = 70°, 2
NEX, 1.9 × 1.9 × 8 mm3, 50 s) and T2* (TR/TEs = 740/
2.1, 4.2, 6.6, 8.9, 11.3, 13.7, 16.1, 18.4 ms, 2 NEX, FA =
18°, 1.9 × 1.9 × 8 mm3, 31 s) maps were sequentially
acquired for ~15 minutes at rest, and for ~45 minutes
post exercise (Figure 1A). The relaxometric values from
small regions in anterior tibialis (TA), soleus (Sol), med-
ial (MG) and lateral gastrocnemius (LG) muscles were
recorded, averaged over both legs and plotted against
time (Figure 1B). Rest, peak exercise, peak-rest differ-
ence, end of exercise recovery and decay rate values was
checked against age and exercise test duration using
Pearson’s correlation.
Results
T1, T2 and T2* demonstrated a significant increase
from rest with exercise, followed by gradual recovery.
T2 at rest (r2_TA = 0.48, r2_Sol = 0.47, r2_MG = 0.44,
r2_LG = 0.53), peak T1, T2 and T2* (r2 = 0.49, 0.52,
and -0.52) in Sol, end of exercise T2 in Sol, MG and LG
(r2 = 0.66, 0.47, and 0.57) and T2 decay rate for TA
(r2 = 0.47) were related to age. The peak-rest differences
of T1, T2 and T2* in MG (r2 = 0.46, 0.53, and 0.61) and
LG (r2 = 0.58, 0.50, and 0.47) were correlated with test
duration (Figure 2).
Conclusions
We investigated treadmill exercise induced changes in
normal calf muscles, and showed the exercise induced
response can be quantified by MR relaxometry, and is age
and exercise duration dependent. In future patient studies,
we will explore the integration of the clinical indices of
disease severity (ABI-Ankle Brachial Index, Initial and
Absolute Claudication Distance) with MR relaxometric
measures to enhance our understanding of the pathophy-
siology and severity of PAD.
Funding
13PRE16950001.
Authors’ details
1Dorothy M Davis Heart and Lung Research Institute, Wexner Medical Center, The
Ohio State University, Columbus, Ohio, USA. 2Department of Biomedical
Engineering, The Ohio State University, Columbus, Ohio, USA. 3Division of
Cardiovascular Medicine, Department of Internal Medicine, Wexner Medical
Center, The Ohio State University, Columbus, Ohio, USA. 4Department of
Radiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio,
USA.
Published: 16 January 2014
doi:10.1186/1532-429X-16-S1-P68
Cite this article as: Varghese et al.: Integrated treadmill stress testing
and MR relaxometry (T1, T2, T2*): response in healthy calf muscles.
Journal of Cardiovascular Magnetic Resonance 2014 16(Suppl 1):P68.
Figure 2 Examples of significant correlations (p < 0.05) observed in relaxometric measures with age (a-c) and treadmill test duration (d-f).
Varghese et al. Journal of Cardiovascular Magnetic
Resonance 2014, 16(Suppl 1):P68
http://www.jcmr-online.com/content/16/S1/P68
Page 2 of 2


http://dx.doi.org/10.1186/1532-429X-16-S1-P68

Integrated treadmill stress testing and MR relaxometry (T1, T2, T2*): response in healthy calf muscles

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