Electronic versus conventional spatiotemporal image correlation (STIC) fetal echocardiography: a direct comparison

Abstract

Objectives: Recent advances in Spatial Temporal Image Correlation (STIC) 4 D fetal echocardiography include the application of eSTIC based on electronic probe image acquisition. We aimed to directly compare the performance of conventional STIC versus eSTIC technique (B-Mode and color Doppler imaging) during off-line reconstruction of STIC/eSTIC fetal heart volume pairs. Methods: Pairs of B-Mode and Color Doppler STIC volumes were acquired sequentially by firstly conventional (STIC) followed by electronic (eSTIC) probes during 33 consecutive obstetric scans at median 23 (range 13-31) gestational weeks. The resulting 66 fetal heart volume pairs were assessed blindly off-line by a fetal cardiologist who documented feasibility of reconstruction, presence of motion artifacts, subjective image quality on a 4-level scale: 1-best to 4-non-diagnostic and morphological diagnosis, to enable a paired comparison of STIC and eSTIC in the same fetus under similar scanning conditions. Results: eSTIC volumes had higher temporal resolution (37 vs. 24 frames per second, p < .001), less motion during acquisition (12 vs. 20 cases, O.R. 7.0, p ¼ .002) and better average image quality (1.9 vs. 2.2, p ¼ .006) compared to STIC volumes. More diagnostic reconstructions were achieved by eSTIC (n ¼ 55, 86%) than STIC (n ¼ 52, 78.8%), p ¼ .001), in a comparable analysis time (mean 4.96 vs. 4.94 min). During a comparison of image quality of the original acquisition (A) and reconstructed planes (B and C planes) e STIC was superior in 22 (33%), 39 (59%) and 21 (38%) volumes, respectively, with the remaining cases being of similar quality (<10% in each plane in favor of STIC). Imaging mode and gestational age had a similar impact on both eSTIC and STIC performance: diagnostically acceptable studies in 49 (75.8%) vs. 48 (72.2%) by B-Mode, 60 (90.9%) vs. 56 (84.8%) by Color Doppler Mode, 8 (62.5%) vs. 10 (50%) in early scans, 38 (95%) vs. 38 (95%) in mid-gestation scans, and 7 (70%) vs. 6 (60%) in third trimester scans. Eight obstetric scans identified a fetus with a cardiac variant or structural abnormality. Diagnostic concordance of the two STIC approaches was comparable (40/48 concordant interpretations, kappa 0.657) all confirmed by fetal and/or postnatal echocardiography. Conclusions: eSTIC was associated with more effective 4 D fetal heart reconstruction due to reduced motion artifacts and superior image quality in all planes, when compared to STIC. Early gestation reconstructions were not generally successful using either technology. Further study is needed to define the cost-effectiveness and diagnostic impact of eSTIC over conventional STIC and their role over, or in addition to, screening 2 D fetal echocardiography by appropriately trained sonographers.

Fetal Vascular Rings and Pulmonary Slings: Strategies for Two- and Three-Dimensional Echocardiographic Diagnosis

“…39 Multiple 2D images are acquired and combined to build a cardiac volume using spatiotemporal image correlation (STIC) or the more advanced electronic STIC technology. 40,41 These techniques have also been adapted to acquire volumes with color information, including color Doppler, power Doppler, HD-flow, and B-flow. 42 Cardiac volumes can be manipulated to display data using several techniques, of which multiplanar display, tomographic ultrasound imaging (TUI), and rendering mode are the most common.…”

Three-Dimensional 3D Ultrasound and Doppler Angiography Imaging in the Prenatal Assessment on Normal and Abnormal Fetal Cardiac Anatomy

“…For example, in the 4-chamber view the anatomy of the heart and great vessels at the moment of acquisition i.e., according to the phase of the cardiac cycle, is contained and stored in volume datasets, the main value of 3D volume is the ability unveil the anatomical information contained i.e., reconstruct 3D spatial images standard planes on a 2D screen in a process called rendering [10]. To obtain volume database during a complete cardiac cycle, temporal dimension information that is present during acquisition has to be incorporated, Spatio-Temporal Image Correlation (STIC) is a new a software modality that unites the spatial and temporal domains resulting in a volume of a complete fetal cardiac cycle displayed in motion by means of a sequence of 3D cineloop that consists of a high number of 2D frames, one behind the other [11,12]. However, extracting and displaying meaningful information from volume datasets is highly expertise-dependent, difficult to perform and require a sound knowledge of fetal anatomy [12].…”

“…To obtain volume database during a complete cardiac cycle, temporal dimension information that is present during acquisition has to be incorporated, Spatio-Temporal Image Correlation (STIC) is a new a software modality that unites the spatial and temporal domains resulting in a volume of a complete fetal cardiac cycle displayed in motion by means of a sequence of 3D cineloop that consists of a high number of 2D frames, one behind the other [11,12]. However, extracting and displaying meaningful information from volume datasets is highly expertise-dependent, difficult to perform and require a sound knowledge of fetal anatomy [12]. It has recently been shown that applying "intelligent navigation" technology to STIC the FINE method can automatically generates and displays eight to nine standard fetal echocardiography views [13].…”

Rings and Slings: Not Such Simple Things

“…The new American Institute of Ultrasound in Medicine guidelines for fetal echocardiography specifically direct clinicians to identify normal pulmonary arterial branching at the same time as looking for fetal arch anomalies [ 26 ]. Three-dimensional (3D) technology has gradually matured into an useful clinical tool to evaluate fetal cardiac anatomy, especially when using spatio-temporal image correlation (STIC) [ 27 – 29 ]. However, the quality of images for both methods is susceptible to the negative impact of certain fetal or maternal factors like fetal position and movement, oligohydramnios, or maternal obesity [ 30 ].…”