Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jan 7;23(1):3.
doi: 10.1186/s12968-020-00696-y.

Splenic switch-off as a predictor for coronary adenosine response: validation against 13N-ammonia during co-injection myocardial perfusion imaging on a hybrid PET/CMR scanner

Dimitri Patriki  1 , Elia von Felten  1 , Adam Bakula  1 , Andreas A Giannopoulos  1 , Christel H Kamani  1 , Moritz Schwyzer  1 , Michael Messerli  1 , Dominik C Benz  1 , Catherine Gebhard  1 , Christoph Gräni  1 , Aju P Pazhenkottil  1 , Philipp A Kaufmann  1 , Tobias A Fuchs  1 , Ronny R Buechel  2
Affiliations

Splenic switch-off as a predictor for coronary adenosine response: validation against 13N-ammonia during co-injection myocardial perfusion imaging on a hybrid PET/CMR scanner

Dimitri Patriki et al. J Cardiovasc Magn Reson. .

Abstract

Background: Inadequate coronary adenosine response is a potential cause for false negative ischemia testing. Recently, the splenic switch-off (SSO) sign has been identified as a promising tool to ascertain the efficacy of adenosine during vasodilator stress cardiovascular magnetic resonance imaging (CMR). We assessed the value of SSO to predict adenosine response, defined as an increase in myocardial blood flow (MBF) during quantitative stress myocardial perfusion 13 N-ammonia positron emission tomography (PET).

Methods: We prospectively enrolled 64 patients who underwent simultaneous CMR and PET myocardial perfusion imaging on a hybrid PET/CMR scanner with co-injection of gadolinium based contrast agent (GBCA) and 13N-ammonia during rest and adenosine-induced stress. A myocardial flow reserve (MFR) of > 1.5 or ischemia as assessed by PET were defined as markers for adequate coronary adenosine response. The presence or absence of SSO was visually assessed. The stress-to-rest intensity ratio (SIR) was calculated as the ratio of stress over rest peak signal intensity for splenic tissue. Additionally, the spleen-to-myocardium ratio, defined as the relative change of spleen to myocardial signal, was calculated for stress (SMRstress) and rest.

Results: Sixty-one (95%) patients were coronary adenosine responders, but SSO was absent in 18 (28%) patients. SIR and SMRstress were significantly lower in patients with SSO (SIR: 0.56 ± 0.13 vs. 0.93 ± 0.23; p < 0.001 and SMRstress: 1.09 ± 0.47 vs. 1.68 ± 0.62; p < 0.001). Mean hyperemic and rest MBF were 2.12 ± 0.68 ml/min/g and 0.78 ± 0.26 ml/min/g, respectively. MFR was significantly higher in patients with vs. patients without presence of SSO (3.07 ± 1.03 vs. 2.48 ± 0.96; p = 0.038), but there was only a weak inverse correlation between SMRstress and MFR (R = -0.378; p = 0.02) as well as between SIR and MFR (R = -0.356; p = 0.004).

Conclusions: The presence of SSO implies adequate coronary adenosine-induced MBF response. Its absence, however, is not a reliable indicator for failed adenosine-induced coronary vasodilatation.

Keywords: Cardiovascular magnetic resonance imaging; Myocardial perfusion imaging; Splenic switch-off.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Example of presence of splenic switch-off sign (SSO) (*) with signal intensity curves. a Stress perfusion, b rest perfusion. SMR  spleen-myocardium intensity ratio, SIR stress-to-rest intensity ratio for spleen
See this image and copyright information in PMC

References

    1. Dilsizian V, Bacharach SL, Beanlands RS, et al. ASNC imaging guidelines/SNMMI procedure standard for positron emission tomography (PET) nuclear cardiology procedures. J Nucl Cardiol. 2016;23:1187–1226. doi: 10.1007/s12350-016-0522-3. - DOI - PubMed
    1. Henzlova MJ, Duvall WL, Einstein AJ, Travin MI, Verberne HJ. ASNC imaging guidelines for SPECT nuclear cardiology procedures: Stress, protocols, and tracers. J Nucl Cardiol. 2016;23:606–639. doi: 10.1007/s12350-015-0387-x. - DOI - PubMed
    1. Nguyen K-L, Bandettini WP, Shanbhag S, Leung SW, Wilson JR, Arai AE. Safety and tolerability of regadenoson CMR. Eur Heart J Cardiovasc Imaging. 2014;15:753–760. doi: 10.1093/ehjci/jet278. - DOI - PMC - PubMed
    1. Writing Committee M, Accf Task Force M ACCF/ACR/AHA/NASCI/SCMR Expert consensus document on cardiovascular magnetic resonance a report of the American College of Cardiology Foundation Task Force on Expert Consensus Documents. Circulation. 2010;2010(121):2462–2508. doi: 10.1161/CIR.0b013e3181d44a8f. - DOI - PMC - PubMed
    1. Mishra RK, Dorbala S, Logsetty G, et al. Quantitative relation between hemodynamic changes during intravenous adenosine infusion and the magnitude of coronary hyperemia: implications for myocardial perfusion imaging. J Am Coll Cardiol. 2005;45:553–558. doi: 10.1016/j.jacc.2004.10.064. - DOI - PubMed

Publication types

MeSH terms