Splenic T1-mapping: a novel quantitative method for assessing adenosine stress adequacy for cardiovascular magnetic resonance

Journal of Cardiovascular Magnetic Resonance

Research

George Krasopoulos¹  Mario Petrou¹  Keith M. Channon²  Stefan K. Piechnik³  Eylem Levelt³  Stefan Neubauer³  Rohan S. Wijesurendra³  Masliza Mahmod³  Vanessa M. Ferreira³  Rina Ariga³  Alexander Liu³  John C. Forfar⁴  Rajesh K. Kharbanda⁵  Andreas Greiser⁶ 

[1] Department of Cardiothoracic Surgery, John Radcliffe Hospital, Oxford, UK;Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK;Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK;Oxford Heart Centre, John Radcliffe Hospital, Oxford, UK;Oxford Heart Centre, John Radcliffe Hospital, Oxford, UK;Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK;Siemens Healthcare GmbH, Erlangen, Germany;

关键词: Cardiovascular magnetic resonance;    Adenosine stress;    Splenic T1;    Switch-off;    ShMOLLI;   

DOI  :  10.1186/s12968-016-0318-2

 received in 2016-10-08, accepted in 2016-12-20,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundPerfusion cardiovascular magnetic resonance (CMR) performed with inadequate adenosine stress leads to false-negative results and suboptimal clinical management. The recently proposed marker of adequate stress, the “splenic switch-off” sign, detects splenic blood flow attenuation during stress perfusion (spleen appears dark), but can only be assessed after gadolinium first-pass, when it is too late to optimize the stress response. Reduction in splenic blood volume during adenosine stress is expected to shorten native splenic T1, which may predict splenic switch-off without the need for gadolinium.MethodsTwo-hundred and twelve subjects underwent adenosine stress CMR: 1.5 T (n = 104; 75 patients, 29 healthy controls); 3 T (n = 108; 86 patients, 22 healthy controls). Native T1spleen was assessed using heart-rate-independent ShMOLLI prototype sequence at rest and during adenosine stress (140 μg/kg/min, 4 min, IV) in 3 short-axis slices (basal, mid-ventricular, apical). This was compared with changes in peak splenic perfusion signal intensity (ΔSIspleen) and the “splenic switch-off” sign on conventional stress/rest gadolinium perfusion imaging. T1spleen values were obtained blinded to perfusion ΔSIspleen, both were derived using regions of interest carefully placed to avoid artefacts and partial-volume effects.ResultsNormal resting splenic T1 values were 1102 ± 66 ms (1.5 T) and 1352 ± 114 ms (3 T), slightly higher than in patients (1083 ± 59 ms, p = 0.04; 1295 ± 105 ms, p = 0.01, respectively). T1spleen decreased significantly during adenosine stress (mean ΔT1spleen ~ −40 ms), independent of field strength, age, gender, and cardiovascular diseases. While ΔT1spleen correlated strongly with ΔSIspleen (rho = 0.70, p < 0.0001); neither indices showed significant correlations with conventional hemodynamic markers (rate pressure product) during stress. By ROC analysis, a ΔT1spleen threshold of ≥ −30 ms during stress predicted the “splenic switch-off” sign (AUC 0.90, p < 0.0001) with sensitivity (90%), specificity (88%), accuracy (90%), PPV (98%), NPV (42%).ConclusionsAdenosine stress and rest splenic T1-mapping is a novel method for assessing stress responses, independent of conventional hemodynamic parameters. It enables prediction of the visual “splenic switch-off” sign without the need for gadolinium, and correlates well to changes in splenic signal intensity during stress/rest perfusion imaging. ΔT1spleen holds promise to facilitate optimization of stress responses before gadolinium first-pass perfusion CMR.

【 授权许可】

CC BY   
© The Author(s). 2017