Quantitative Perfusion

1350622 - Reliability of fully automated, inline quantitative assessment of myocardial perfusion in patients with suspected coronary artery disease

Thursday, January 26, 2023

4:30 PM – 5:10 PM

Location: Pacific Jewel

Presenting Author(s)

ME

Mohamed Elshibly, Dr

Clinical Research Fellow
The University of Leicester, United Kingdom

Primary Author(s)

ME

Mohamed Elshibly, Dr

Clinical Research Fellow
The University of Leicester, United Kingdom

Co-Author(s)

RE

Rachel England

Senior Radiographer
Glenfield Hospital, United Kingdom
KP

Kelly Parke, BSc

Senior Radiographer
University of Leicester, United Kingdom
JW

Joanne Wormleighton, DCR(R)

Lead Research Radiographer
Glenfield Hospital
Leicester, England, United Kingdom
CB

Charley Budgeon

Lecturer/Biostatistician
The University of Western Australia, Australia
Gaurav S. Gulsin, PhD

Academic clinical lecturer
University of Leicester
Leicester, England, United Kingdom
HX

Hui Xue, PhD

Director, Imaging AI Program
National Institutes of Health
Bethesda, Maryland, United States
PK

Peter Kellman, PhD

Senior Scientist
National Institutes of Health, Maryland, United States
Gerry P. McCann, MD

NIHR research professor
University of Leicester
Leicester, England, United Kingdom
JA

Jayanth Arnold, PhD

Associate Professor
University of Leicester, England, United Kingdom

Disclosure(s):

Gerry P. McCann, MD: No financial relationships to disclose

Background: Recent developments in the field of myocardial perfusion assessment with cardiovascular magnetic resonance (CMR) enable the automated inline quantification of myocardial blood flow (MBF).(1) This offers potential advantages over qualitative assessment of images, providing an objective, quantitative and serially evaluable endpoint. Previous studies have assessed the reliability of quantitative myocardial perfusion assessment by CMR in healthy volunteers only.(2) This study assessed the reproducibility of this technique in patients with suspected stable coronary artery disease (CAD).

Methods: Patients with suspected CAD were studied with CMR perfusion assessment at 3-Tesla on two separate days. CMR perfusion imaging was performed at rest and during adenosine stress (140-210mcg/kg/min) using a dual-sequence T1-weighted saturation recovery gradient echo sequence acquired over 60 heartbeats, following intravenous injection of 0.075mmol/kg of a gadolinium-based contrast agent (Dotarem) followed by 20ml saline bolus (injection speed 4ml/s). Inline automatic reconstruction and image post-processing were implemented within the Gadgetron software framework, calculating MBF using a blood tissue exchange model, displayed on pixel-wise perfusion maps.(1) Perfusion maps were blindly analysed offline by manually tracing endocardial and epicardial contours for each slice, and applying a 10% offset for each border. Segmental MBF was calculated, applying the 16-segment American Heart Association (AHA) model.(3) Myocardial perfusion reserve (MPR) was defined as the ratio of segmental hyperemic MBF/rest MBF [uncorrected for rate-pressure product]. Reliability of global stress and rest MBF, and MPR were evaluated using Bland-Altman plots and intraclass correlation coefficients (ICC).(4)

Results: 34 patients (mean age 67±10 years, 73% male) were studied. The median interval between the two scans was three days. There was no significant interstudy difference in global stress MBF between the two scans (1.42±0.51ml/min/g vs 1.38±0.60ml/min/g, p=0.66), global rest MBF (0.56±0.12ml/min/g vs 0.55±0.16ml/min/g, p=0.81) or global MPR (2.52±0.72 vs 2.32±0.57, p=0.16). Stress MBF, rest MBF and MPR showed intraclass correlations of 0.63 (95%CI 0.34-0.81), 0.75 (95%CI 0.51-0.88) and 0.51 (95%CI 0.12-0.75), respectively (Bland-Altman plots in Figures 1, 2 and 3).

Conclusion: In patients with suspected CAD, quantitative assessment of myocardial perfusion by fully automated inline myocardial mapping shows moderate-good reliability for both stress and rest MBF, but poorer correlation with MPR.