Evaluating fetal tricuspid and mitral annular plane systolic excursion (TAPSE and MAPSE) using spatiotemporal image correlation (STIC) M-mode.

OBJECTIVES:This study aimed to evaluate the feasibility and reliability of tricuspid and mitral annular plane systolic excursion measurements (TAPSE and MAPSE) applying M-mode spatiotemporal image correlation (STIC) technology in low-risk pregnancies. METHODS:An initial retrospective pilot study was carried out to assess repeatability, followed by a larger mixed cross-sectional and prospective longitudinal study, both evaluating low-risk singleton pregnancies between 22+6 and 39+1 weeks. As only annuli capture was necessary, STIC acquisition parameters were set to the minimum volume angle of 15° and acquisition time of 7.5 s. RESULTS:A total of 330 volumes were analysed offline applying STIC M-mode. Acquisition rates were 96.9 % for TAPSE and 93.7 % MAPSE in the pilot study (n=32) and 98.0 % for both in the longitudinal study (n=102). Both study designs revealed good repeatability for both sides of the heart, with higher intraclass correlation coefficients (ICCs) for TAPSE (0.84-0.94) compared to MAPSE (0.80-0.88). Good repeatability was demonstrated for both sides of the heart, more so for TAPSE than MAPSE, with ICCs for TAPSE 0.84-0.91 and MAPSE 0.75-0.76, comparable to prior ICCs for STIC repeatability. CONCLUSIONS:Modified STIC acquisition settings specifically tailored for capturing the longitudinal annular displacement may improve STIC TAPSE and MAPSE acquisition rates, optimising image quality for precise measurement and potentially bringing these modalities closer to clinical application.