The relative contributions of myocardial perfusion, blood volume and extracellular volume to native T1 and native T2 at rest and during adenosine stress in normal physiology

Abstract

BackgroundBoth ischemic and non-ischemic heart disease can cause disturbances in the myocardial blood volume (MBV), myocardial perfusion and the myocardial extracellular volume fraction (ECV). Recent studies suggest that native myocardial T1 mapping can detect changes in MBV during adenosine stress without the use of contrast agents. Furthermore, native T2 mapping could also potentially be used to quantify changes in myocardial perfusion and/or MBV. Therefore, the aim of this study was to explore the relative contributions of myocardial perfusion, MBV and ECV to native T1 and native T2 at rest and during adenosine stress in normal physiology.MethodsHealthy subjects (n = 41, 26 ± 5 years, 51% females) underwent 1.5 T cardiovascular magnetic resonance (CMR) scanning. Quantitative myocardial perfusion [ml/min/g] and MBV [%] maps were computed from first pass perfusion imaging at adenosine stress (140 microg/kg/min infusion) and rest following an intravenous contrast bolus (0.05 mmol/kg, gadobutrol). Native T1 and T2 maps were acquired before and during adenosine stress. T1 maps at rest and stress were also acquired following a 0.2 mmol/kg cumulative intravenous contrast dose, rendering rest and stress ECV maps [%]. Myocardial T1, T2, perfusion, MBV and ECV values were measured by delineating a region of interest in the midmural third of the myocardium.ResultsDuring adenosine stress, there was an increase in myocardial native T1, native T2, perfusion, MBV, and ECV (p ≤ 0.001 for all). Myocardial perfusion, MBV and ECV all correlated with both native T1 and native T2, respectively (R2 = 0.35 to 0.61, p < 0.001 for all).Multivariate linear regression revealed that ECV and perfusion together best explained the change in native T2 (ECV beta 0.21, p = 0.02, perfusion beta 0.66, p < 0.001, model R2 = 0.64, p < 0.001), and native T1 (ECV beta 0.50, p < 0.001, perfusion beta 0.43, p < 0.001, model R2 = 0.69, p < 0.001).ConclusionsMyocardial native T1, native T2, perfusion, MBV, and ECV all increase during adenosine stress. Changes in myocardial native T1 and T2 during adenosine stress in normal physiology can largely be explained by the combined changes in myocardial perfusion and ECV.Trial registrationClinicaltrials.gov identifier NCT02723747. Registered March 16, 2016.

2020 - State of our JCMR

“…The Pohost Runner-up Prize was awarded to Dr. Nickander for “The relative contributions of myocardial perfusion, blood volume and extracellular volume to native T1 and native T2 at rest and during adenosine stress in normal physiology. [ 15 ].…”

“…[ 13 ] Gotschy et al Characterizing cardiac involvement in amyloidosis using cardiovascular magnetic resonance diffusion tensor imaging [ 14 ] Gräni et al Comparison of myocardial fibrosis quantification methods by cardiovascular magnetic resonance imaging for risk stratification of patients with suspected myocarditis [ 8 ] Holtackers et al Clinical value of dark-blood late gadolinium enhancement cardiovascular magnetic resonance without additional magnetization preparation [ 12 ] Nickander et al . ** The relative contributions of myocardial perfusion, blood volume and extracellular volume to native T1 and native T2 at rest and during adenosine stress in normal physiology [ 15 ] Rodrigues et al Repaired coarctation of the aorta, persistent arterial hypertension and the selfish brain [ 16 ] Seitz et al Impact of caffeine on myocardial perfusion reserve assessed by semiquantitative adenosine stress perfusion cardiovascular magnetic resonance. J Cardiovasc Magn Reson.…”

Pathophysiology, classification, and MRI parallels in microvascular disease of the heart and brain

“…Recent work using native T1 stress mapping demonstrated utility among patients with aortic stenosis and those with epicardial CAD, 70 as well as the effect of adenosine vasodilation on myocardial T1, T2, MBV, and extracellular volume measurements during normal physiology. 71 However, given the ability of T1 mapping to detect alterations in MBV, it may allow for the earlier detection and treatment of patients with CMD. Several myocardial T1 mapping sequences exist 72 including the modified Look-Locker inversion recovery (MOLLI), shortened modified Look-Locker inversion recovery (ShMOLLI), and saturation recovery single-shot acquisition (SASHA).…”

“…Recent work using native T1 stress mapping demonstrated utility among patients with aortic stenosis and those with epicardial CAD, 70 as well as the effect of adenosine vasodilation on myocardial T1, T2, MBV, and extracellular volume measurements during normal physiology 71 . However, given the ability of T1 mapping to detect alterations in MBV, it may allow for the earlier detection and treatment of patients with CMD.…”

Diffusely Increased Myocardial Extracellular Volume With or Without Focal Late Gadolinium Enhancement

“…Healthy volunteers (n = 38) were also included in order to establish the normal range for ECV. These subjects were originally included for another study (56), and these volunteers had no medical history of cardiovascular disease, kidney disease, or asthma, had no previous or current use of cardiovascular drugs, and none were current smokers.…”