Splenic switch off as a novel marker for adenosine response in 13N-ammonia PET myocardial perfusion imaging – a pilot study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Bakula ◽  
D Patriki ◽  
E Von Felten ◽  
G Benetos ◽  
A Sustar ◽  
...  
Keyword(s):  
Myocardial Perfusion Imaging ◽  
Myocardial Perfusion ◽  
Contrast Agent ◽  
Perfusion Imaging ◽  
Microvascular Dysfunction ◽  
Standard Uptake Value ◽  
Funding Source ◽  
National Budget ◽  
Induced Stress ◽  
Potential Marker

Abstract Background Positron emission tomography myocardial perfusion imaging (PET MPI) is a robust and excellent tool for assessing ischemia. So far, however, no methodology has been established to distinguish truly reduced MFR due to microvascular dysfunction or three-vessel coronary disease (CAD) from seemingly impaired MFR due to inadequate adenosine response. Conversely, for cardiac stress magnetic resonance (CMR) the adenosine induced splenic switch-off (SSO) sign has been proposed as a potential marker for adequate adenosine response. Purpose We assessed the feasibility of detecting SSO in adenosine stress 13N-ammonia PET MPI using SSO in CMR as the standard of reference. Methods 50 patients underwent simultaneous PET MPI and CMR on a hybrid PET/MR device with co-injection of 13N-ammonia and a gadolinium-based contrast agent during rest and adenosine-induced stress. In CMR, SSO was assessed qualitatively and quantitatively by calculating the ratio of the peak signal intensity of the spleen during stress over rest (SIR). Similarly, in PET MPI the splenic signal activity ratio (SAR) was calculated as the proportion of the maximal standard uptake value of the spleen in stress and rest. Additionally, MFR was quantified in PET MPI. Results Visual SSO in CMR was present in 37 (74%) patients, whereas 13 patients had no SSO. The median SIR in CMR was significantly lower in patients with visual SSO compared to patients without visual SSO (0.57 [IQR 0.49–0.62] vs. 0.89 [IQR 0.76–0.98]; p<0.001). Similarly, median SAR in PET was significantly lower in patients with visual SSO in CMR compared to patients without visual SSO (0.4 [IQR 0.32–0.45] vs. 0.8 [IQR 0.47–0.98]; p<0.001). SIR correlated significantly with SAR (r=0.4, p<0.05). Mean MFR was significantly higher in patients with visual SSO compared to patients without visual SSO (3.38±0.86 vs. 2.53±0.84; p<0.05). Conclusion Similarly to CMR, SSO can be detected in 13N-ammonia PET MPI. This might help distinguish adenosine non-responders from patients with truly impaired MFR due to microvascular dysfunction or multivessel CAD. Figure 1. Splenic switch off (*) illustrated on transaxial 13N-ammonia PET MPI stress (A) compared to rest perfusion images (B) and similarly in stress (C) and rest (D) short axis CMR (**) in the same patient during adenosine induced stress and co-injection of 13N-ammonia and a gadolinium based contrast agent, acquired on a hybrid PET/MR device. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation (SNSF)

scholarly journals Splenic switch-off as a novel marker for adenosine response in nitrogen-13 ammonia PET myocardial perfusion imaging: Cross-validation against CMR using a hybrid PET/MR device

2020 ◽  
Author(s):  
Adam Bakula ◽  
Dimitri Patriki ◽  
Elia von Felten ◽  
Georgios Benetos ◽  
Aleksandra Sustar ◽  
...  
Keyword(s):  
Myocardial Perfusion Imaging ◽  
Myocardial Perfusion ◽  
Perfusion Imaging ◽  
Microvascular Dysfunction ◽  
Standard Uptake Value ◽  
Flow Reserve ◽  
Potential Marker ◽  
Positron Emission ◽  
Nitrogen 13 Ammonia ◽  
Artery Disease

Abstract Background No methodology is available to distinguish truly reduced myocardial flow reserve (MFR) in positron emission tomography myocardial perfusion imaging (PET MPI) from seemingly impaired MFR due to inadequate adenosine response. The adenosine-induced splenic switch-off (SSO) sign has been proposed as a potential marker for adequate adenosine response in cardiac magnetic resonance (CMR). We assessed the feasibility of detecting SSO in nitrogen-13 ammonia PET MPI using SSO in CMR as the standard of reference. Methods and Results Fifty patients underwent simultaneous CMR and PET MPI on a hybrid PET/MR device with co-injection of a gadolinium-based contrast agent and nitrogen-13 ammonia during rest and adenosine-induced stress. In CMR, SSO was assessed visually (positive vs negative SSO) and quantitatively by calculating the ratio of the peak signal intensity of the spleen during stress over rest (SIR). In PET MPI, the splenic signal activity ratio (SAR) was calculated as the maximal standard uptake value of the spleen during stress over rest. The median SIR was significantly lower in patients with positive versus negative SSO in CMR (0.57 [IQR 0.49 to 0.62] vs 0.89 [IQR 0.76 to 0.98]; P < .001). Similarly, median SAR in PET MPI was significantly lower in patients with positive versus negative SSO (0.40 [IQR 0.32 to 0.45] vs 0.80 [IQR 0.47 to 0.98]; P < .001). Conclusion Similarly to CMR, SSO can be detected in nitrogen-13 ammonia PET MPI. This might help distinguish adenosine non-responders from patients with truly impaired MFR due to microvascular dysfunction or multivessel coronary artery disease.

scholarly journals MYOCARDIAL PERFUSION IMAGING WITH AN EXTRAVASCULAR CONTRAST AGENT

ASAIO Journal ◽  
1996 ◽  
Vol 42 (2) ◽  
pp. 128
Author(s):  
Christine H. Lorenz ◽  
Paul A. Harris ◽  
Knowles A. Overholser ◽  
Stefan E. Fischer ◽  
Samuel A. Wickline
Keyword(s):  
Myocardial Perfusion Imaging ◽  
Myocardial Perfusion ◽  
Contrast Agent ◽  
Perfusion Imaging

MYOCARDIAL PERFUSION IMAGING WITH AN EXTRAVASCULAR CONTRAST AGENT

ASAIO Journal ◽  
1996 ◽  
Vol 42 (2) ◽  
pp. 128
Author(s):  
Christine H. Lorenz ◽  
Paul A. Harris ◽  
Knowles A. Overholser ◽  
Stefan E. Fischer ◽  
Samuel A. Wickline
Keyword(s):  
Myocardial Perfusion Imaging ◽  
Myocardial Perfusion ◽  
Contrast Agent ◽  
Perfusion Imaging

scholarly journals Coronary CT angiography derived features for predicting an abnormal pet myocardial perfusion imaging: a machine learning approach

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
P Kafouris ◽  
G Kalykakis ◽  
A Antonopoulos ◽  
P Siogkas ◽  
R Liga ◽  
...  
Keyword(s):  
Machine Learning ◽  
Myocardial Perfusion Imaging ◽  
Myocardial Perfusion ◽  
Functional Assessment ◽  
Perfusion Imaging ◽  
Plaque Burden ◽  
Funding Source ◽  
Flow Reserve ◽  
Pet Myocardial Perfusion Imaging ◽  
Myocardial Flow

Abstract Background Computed Tomography Coronary Angiography (CTCA) is an effective non-invasive imaging modality for anatomo-functional assessment of coronary artery disease (CAD). Machine learning (ML) algorithms allow extraction and process of useful information from multidimensional spaces for evaluation of coronary lesions. Purpose To investigate the ability of ML to integrate computational fluid dynamics (CFD) derived parameters with quantitative plaque burden, plaque morphology and anatomical characteristics for predicting impaired myocardial flow reserve by PET myocardial perfusion imaging (MPI). Methods 49 patients (29 male, mean age 65.3±6.3 years) with intermediate pre-test likelihood of CAD who underwent CTCA and PET-MPI were included. PET was considered positive when &gt;1 contiguous segment demonstrated Myocardial flow reserve (MFR) ≤2.5 mL/g/min for 15O-water or ≤2.0 for 13N-ammonia respectively. CDF derived parameters such as a previously validated CT-FFR surrogate, virtual functional assessment index (vFAI), segmental endothelial shear stress (ESS), as well as anatomical and plaque characteristics were assessed. k-nearest neighbor (k-NN), support vector machines (SVM) and feedforward neural networks (FF-NN) were implemented. ML was internally validated using 5-fold cross validation, repeated 100 times. Using sequential forward selection (SFS), the 5 highest rank features based on appearances in each classification scheme were selected and following exhaustive search (ES) the best features combinations were identified. Each classifier's performance was evaluated using an area-under-receiver operating characteristic curve (AUC) analysis. Results 85 coronary segments were analyzed and 28 features derived from CTCA were extracted. The features ranking for every classifier are depicted in Figure 1. k-NN using a combination only of ESS in the proximal (ESSprox) and distal segment achieved an AUC=0.78 (Sens=0.71, Spec=0.77, p&lt;0.05) for predicting a positive PET result. Combining ESSprox with burden fibrofatty tissue and non-calcified plaque burden, SVM achieved an AUC=0.75 (Sens=0.74, Spec=0.67, p&lt;0.05) whilst for FF-NN, the corresponding AUC was 0.79 (Sens=0.76, Spec=0.7, p&lt;0.05) using ESSprox, vFAI and % Fibrofatty volume. Among the best features combinations, ESSprox was the most consistent one achieving an AUC=0.75 (Sens=0.66, Spec=0.73, p&lt;0.05) for k-NN, AUC=0.73 (Sens=0.58, Spec=0.59, p&lt;0.05), for SVM and an AUC=0.73 (Sens=0.63, Spec=0.62, p&lt;0.05) for FF-NN respectively. Conclusion ML analysis is feasible for predicting abnormal MFR by PET using a combination of CFD derived parameters, anatomical and morphological features. ESSprox was present in every combination of best features. As a single characteristic was a moderate predictor of impaired MFR, whilst in combination with plaque characteristics and CFD derived features resulted in improved sensitivity and specificity. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – EU funding. Main funding source(s): This research is co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme “Human, Resources Development, Education and Lifelong Learning 2014-2020” in the context of the project “Assessment of coronary atherosclerosis: a new complete, anatomo-functional, morphological and biomechanical approach” and from p-Med GR 5002802

Coronary microvascular dysfunction: An important interpretation on the clinical significance of transient ischemic dilation of the left ventricle on myocardial perfusion imaging

2021 ◽  
pp. 1-14
Author(s):  
Liang Chen ◽  
Min Zhang ◽  
Jinqi Jiang ◽  
Bei Lei ◽  
Xiaoyan Sun
Keyword(s):  
Myocardial Perfusion Imaging ◽  
Myocardial Perfusion ◽  
Clinical Significance ◽  
Intravenous Administration ◽  
Perfusion Imaging ◽  
Microvascular Dysfunction ◽  
Transient Ischemic Dilation ◽  
Coronary Microvascular Dysfunction ◽  
Post Intervention ◽  
Group A

PURPOSE: To further investigate the clinical significance of transient ischemic dilation (TID) on myocardial perfusion imaging (MPI) by analyzing the effect of anisodamine hydrobromide (a drug that can effectively ameliorate microcirculation) on the patients with isolated TID and the findings of previous literatures. METHODS: Total 107 patients with isolated TID (TID value≥1.11) were randomly divided into group A (n = 36; intravenous administration of anisodamine hydrobromide), group N (n = 36; intravenous administration of isosorbide dinitrate), and group C (n = 35; intravenous administration of normal saline). MPI and treadmill exercise test (TET) were performed again after 14-day course of intervention. Pre- and post-intervention frequencies of symptom were recorded. RESULTS: In group A, after intervention of anisodamine hydrobromide, the summed stress score (SSS) and TID value on MPI significantly decreased than those before intervention (P <  0.001), the durations of exercise (DEs) and metabolic equivalents (METs) in TET notably ascended (P <  0.001), as well as the symptom remarkably improved. In group N and group C, there were no significant differences in SSS, TID value, DEs, METs, and frequencies of symptom between pre- and post-intervention (P >  0.05). No significant improvement of symptoms in group N before and after treatment. CONCLUSIONS: TID with perfusion defect may usually predict a possibility of severe and extensive coronary artery disease (CAD). An isolated TID should be considered as a likelihood of coronary microvascular dysfunction (CMD). TET and coronary CT angiography (cCTA) are extremely helpful for the antidiastole on CAD and CMD. The administration of anisodamine hydrobromide might be an optional treatment for the patients with isolated TID.

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