CMR-Analysis (including machine learning)

1356509 - Strain CMR Can Predict Regions of Inflammation on PET/CT in Patients with Cardiac Sarcoidosis

Friday, January 27, 2023

10:20 AM – 11:00 AM

Location: Pacific Jewel

Presenting Author(s)

MA

Mohamed Abdelmotleb, MD

Cardiothoracic Imaging Fellow
University of Washington, United States

Primary Author(s)

MS

Mehrzad Shafiei, MD

Post Doctoral Scholar
University of Washington, United States

Co-Author(s)

MA

Mohamed Abdelmotleb, MD

Cardiothoracic Imaging Fellow
University of Washington, United States
AG

Avanti Gulhane, MD

Acting Clinical Instructor
University of Washington
Seattle, Washington, United States
MS

Murat Sadic, MD, PhD

Resident
University of Washington
Seattle, Washington, United States
HC

Hamid Chalian, MD

Associate Professor of Radiology
University of Washington, United States
HV

Hubert Vesselle, MD, PhD

Professor of Nuclear Medicine
University of Washington, United States
GR

Ganesh Raghu, MD

Professor of of Pulmonary, Critical Care and Sleep Medicine
University of Washington, United States
Karen Ordovas, MD, MAS

Professor of Radiology, Cardiothoracic Imaging Section Chief, Associate Vice-Chair for Academic Affairs
University of Washington
Kirkland, Washington, United States

Background: Regional CMR-derived myocardial strain parameters can be used to detect early abnormalities in cardiac function, but their ability to predict the presence of myocardial inflammation is unknown. PET/CT is currently considered the gold standard for detection of myocardial inflammation in cardiac sarcoidosis (CS). We aimed to determine if CMR strain parameters can predict segments with inflammation on PET/CT in this population.

Methods:
We retrospectively identified consecutive patients with confirmed or probable CS per the updated Japanese Circulation Society Guideline, with both CMR and F18-FDG PET/CT within 90 days of each other in the past 5 years. CMR steady state free precession images were used for feature tracking analysis of AHA segments using commercial software (Circle CVI42).

Circumferential and longitudinal components of strain were obtained. Late gadolinium enhancement (LGE) images were reviewed to identify abnormalities per segment. F18-FDG PET/CT studies were reviewed for subjective presence of FDG uptake above blood pool and were defined as positive or negative for inflammation.
Comparison of strain CMR parameters between segments with and without inflammation on PET/CT was performed using t-test or non-parametric test of hypothesis depending on variable distribution. Logistic regression was obtained to assess if strain association with inflammation was independent from the presence of LGE.

Results: The study included 26 patients, mean age 54.6 years, 55% male. Segmental analysis showed 130/416 myocardial segments with inflammation on PET/CT. Out of 374 segments (90%) analyzed for the presence of LGE, 272 (72%) showed abnormalities. The majority of segments with inflammation showed LGE (105/117(90%)). Peak circumferential strain was reduced in segments with inflammation on PET/CT versus those without (mean = -10.9 (SD = 10.4) vs mean = -15.3(SD = 7.5) , p< 0.001) (fig. 1). Using -13 as a cut off for normal peak circumferential strain per segment, abnormal strain was associated with a 1.7 fold increase in likelihood of inflammation on PET/CT. The association between circumferential strain and presence of uptake on PET/CT was independent of the presence of LGE on logistic regression analysis. Diastolic circumferential strain rate was lower on FDG-positive segments compared to FDG-negative segments (mean = 0.98 (SD = 0.99) vs 1.27 (SD = 0.76); p=0.0012) (fig. 2). This association was not independent of LGE. On a per-patient analysis, LVEF & LVEDV were significantly different between patients with inflammation on PET/CT versus those without.

Conclusion: In CS, abnormal p</span>eak circumferential strain was associated with the presence of inflammation in myocardial segments on PET/CT studies. This association was independent from the presence of LGE. There was an association between segmental diastolic circumferential strain rate and inflammation on PET/CT studies, however, not independently from LGE. Strain CMR can potentially detect active CS without the need of gadolinium.