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.