TY  - JOUR
SN  - 0033-8419
PB  - Radiological Society of North America
VL  - 272
EP  - 406
Y1  - 2014///
SP  - 397
A1  - Yang, Hsin-Jung
A1  - Yumul, Roya
A1  - Tang, Richard
A1  - Cokic, Ivan
A1  - Klein, Michael
A1  - Kali, Avinash
A1  - Sobczyk, Olivia
A1  - Sharif, Behzad
A1  - Tang, Jun
A1  - Bi, Xiaoming
A1  - Tsaftaris, Sotirios A.
A1  - Li, Debiao
A1  - Conte, Antonio Hernandez
A1  - Fisher, Joseph A.
A1  - Dharmakumar, Rohan
AV  - none
ID  - eprints2266
TI  - Assessment of myocardial reactivity to controlled hypercapnia with free-breathing T2-prepared cardiac blood oxygen level?dependent MR imaging
UR  - http://dx.doi.org/10.1148/radiol.14132549
IS  - 2
JF  - Radiology
N2  - Purpose: To examine whether controlled and tolerable levels of hypercapnia may be an alternative to adenosine, a routinely used coronary vasodilator, in healthy human subjects and animals. Materials and Methods: Human studies were approved by the institutional review board and were HIPAA compliant. Eighteen subjects had end-tidal partial pressure of carbon dioxide (PetCO2) increased by 10 mm Hg, and myocardial perfusion was monitored with myocardial blood oxygen level?dependent (BOLD) magnetic resonance (MR) imaging. Animal studies were approved by the institutional animal care and use committee. Anesthetized canines with (n = 7) and without (n = 7) induced stenosis of the left anterior descending artery (LAD) underwent vasodilator challenges with hypercapnia and adenosine. LAD coronary blood flow velocity and free-breathing myocardial BOLD MR responses were measured at each intervention. Appropriate statistical tests were performed to evaluate measured quantitative changes in all parameters of interest in response to changes in partial pressure of carbon dioxide.
Results: Changes in myocardial BOLD MR signal were equivalent to reported changes with adenosine (11.2% ± 10.6 [hypercapnia, 10 mm Hg] vs 12% ± 12.3 [adenosine]; P = .75). In intact canines, there was a sigmoidal relationship between BOLD MR response and PetCO2 with most of the response occurring over a 10 mm Hg span. BOLD MR (17% ± 14 [hypercapnia] vs 14% ± 24 [adenosine]; P = .80) and coronary blood flow velocity (21% ± 16 [hypercapnia] vs 26% ± 27 [adenosine]; P > .99) responses were similar to that of adenosine infusion. BOLD MR signal changes in canines with LAD stenosis during hypercapnia and adenosine infusion were not different (1% ± 4 [hypercapnia] vs 6% ± 4 [adenosine]; P = .12). Conclusion: Free-breathing T2-prepared myocardial BOLD MR imaging showed that hypercapnia of 10 mm Hg may provide a cardiac hyperemic stimulus similar to adenosine.
ER  -