Description of automated and manual protocols
The automated protocols are predetermined TEE protocols created for specific clinical indications to produce an automated protocol driven TEE exam. Each protocol is created to evaluate a specific pathology in question and to provide standardized TEE views for all exams (Supplemental Table 1). Once developed, the automated protocol automatically adjusts and changes the echo machine image acquisition settings, angles, and views to specifically target the next desired TEE view and image acquisition, including adjusting settings for 2D, 3D, pulse wave, continuous wave, and color Doppler image acquisitions. The automated protocol will adjust the settings on the echo machine console to the next desired view (i.e. left atrial appendage biplane 30/120 degree or mitral valve pulse wave Doppler 2D 0 degrees). Once the automated protocol changes to the next defined image acquisition, the operator manually moves the TEE probe within the esophagus to the appropriate orientation and depth within the esophagus for the specific image (i.e. mid-esophageal, trans-gastric, etc.). Angle, color Doppler, continuous/pulse wave Doppler, and 3D are all automatically changed by the automated protocol. The sonographer may then adjust desired echo machine settings to optimize image acquisition for that specific view based on patient anatomy, operator movement, or other exam specific variables. Examples of sonographer adjustments would be gain, doppler scale, aliasing velocity, etc.). This results in an overall semi-automated process using both automated settings while allowing for manual input/adjustment based on patient and image characteristics. By having pre-defined views, the automated protocol will advance to the next desired image view immediately after image acquisition and ensures all required views/images are attempted/obtained. A screenshot of the echo machine console during the automated protocol is shown in Figure 1.
The three automated protocols created within our academic echocardiography lab for the evaluation of AF, MR, and AS were used and included image acquisitions specific for each pathology
The manual TEE image acquisition proceeded according to the operator’s and sonographer’s discretion with the stated goal of a complete TEE exam and acquisition of necessary images for each pathology. In the manual protocol, the sonographer aids in all adjustment of ultrasound angles, Doppler functions, zoom images, activation/optimization of 3D image acquisition, and any other adjustments necessary for image acquisition.
Any additional images that were later determined to be clinically indicated and not acquired within the manual or automated protocols were subsequently obtained at the completion of each protocol and not included in analysis.
TEE image quality on both manual and automated protocols were assessed by an independent echocardiographer after the acquisition. The rating echocardiographer was blinded from which protocol was used to obtain each sequence of images. Each image was graded on an ordinal scale consisting of three levels for image quality: 0 - poor, 1 - fair, and 2 - good. Assuming an equal interval between the three levels, the scores were averaged per the protocol and a paired sample t-test analysis was conducted to determine whether the image quality differed between the manual and the automated protocols.