English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Perfusion 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.    Methods  Two-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 T1 spleen  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 (ΔSI spleen ) and the “splenic switch-off” sign on conventional stress/rest gadolinium perfusion imaging. T1 spleen  values were obtained blinded to perfusion ΔSI spleen , both were derived using regions of interest carefully placed to avoid artefacts and partial-volume effects.    Results  Normal 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). T1 spleen  decreased significantly during adenosine stress (mean ΔT1 spleen  ~ −40 ms), independent of field strength, age, gender, and cardiovascular diseases. While ΔT1 spleen  correlated strongly with ΔSI spleen  (rho = 0.70,  p  < 0.0001); neither indices showed significant correlations with conventional hemodynamic markers (rate pressure product) during stress. By ROC analysis, a ΔT1 spleen  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%).    Conclusions  Adenosine 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. ΔT1 spleen  holds promise to facilitate optimization of stress responses before gadolinium first-pass perfusion CMR.    Electronic supplementary material  The online version of this article (doi:10.1186/s12968-016-0318-2) contains supplementary material, which is available to authorized users.

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