FIGURE LEGEND
FIGURE 1 Mathematical coordinate system for different imaging
modalities
(A) Computed tomography multi-planar reconstruction is based on
Cartesian coordinate system. (B) Fluoroscopy is the projection
in the direction of image intensifier, which is of spherical coordinate
system. Spider view of left coronary artery is yielded from the left
anterior oblique (LAO)/ caudal (CAU) projection. (C)Trans-esophageal echocardiography imaging reference plane is similar to
the polar coordinate plane in the cylindrical coordinate system. 1-3= spatial orientation of different TEE sectors (1 =Transgastric left ventricular short axis view; 2&3 = Two
orthogonal mid-esophageal views); Blue circle = mid-esophageal
level; Orange circle = transgastric level; AsAo = ascending
aorta; DsAo = descending aorta; LA = left atrium; LAD = left anterior
descending artery; LCX = left circumflex artery; LM = left main trunk;
LV = left ventricle; LV = left ventricular outflow tract; RV = right
ventricle.
FIGURE 2 Methods of stepwise multi-planar reconstruction (MPR)
to simulate trans-esophageal echocardiography (TEE) from cardiac
computed tomography (CT)
LEFT: Step 1: Invert the z-axis. Eye symbols and colored human models
describe the visual perspectives of the CT slices. After obtaining top
visual perspective, crosshairs are moved into the esophageal lumen
(shorter yellow arrow). Step 2: Turn to the left. On the axial MPR plane
(red box), sagittal MPR line is rotated to cross the center of mitral
valve. Slight retroflex is added to avoid foreshortening on 4-chamber
view (blue box). Steps 3: Rotate. On coronal MPR plane (green box),
axial MPR line is rotated to obtain 2-chamber and 3-chamber (long-axis)
view. RIGHT: Similarity in configuration is examined by overlaying the
yielded CT slices with the corresponded TEE views. ALPM = anterolateral
papillary muscle; AsAo = ascending aorta; AV = aortic valve; DsAo =
descending aorta; LA = left atrium; LV = left ventricle; MV = mitral
valve; PMPM = posteromedial papillary muscle; RA = right atrium; RSPV =
right superior pulmonary vein; RV = right ventricle; RVOT = right
ventricular outflow tract.
FIGURE 3 Flex to the right
(A) Orange box: Decomposition of trans-esophageal
echocardiography (TEE) probe “flex to the right” movement into
displacement and negative rotation of the Cartesian coordinate system.(B) Effect of “flex to the right” on mid-esophageal left
ventricle 4-chamber view: the left ventricular outflow tract (LVOT) is
revealed due to the “negative rotation” component, and is offset with
a compensatory positive rotation. (C) Cardiac tomography
multi-planar reconstruction simulation. Without “flex to the right”,
the line of symmetry of the TEE scanning sector is close to the lateral
mitral annulus. As a result, the rotation-yielded bi-commissural view is
compromised (left lower green box). With “flex to the right”, the line
of symmetry of the TEE scanning sector is displaced toward the center of
mitral valve, and the LVOT is again revealed due to the “negative
rotation” component. Compensatory positive rotation and rotated degree
for bi-commissural view are illustrated with the right lower green box,
and better bi-commissural view is obtained. AsAo = ascending
aorta; DsAo = descending aorta; Eso = esophagus; LA =left atrium; LV = left ventricle; LV = left ventricle
outflow tract; RA = right atrium; RV = right
ventricle; RVOT = right ventricular outflow tract; S = spine.
FIGURE 4 Flex to the left with anteflexed echo probe
(A) Orange box: Decomposition of trans-esophageal
echocardiography (TEE) probe “flex to the left during anteflex”
movement into rotation about the esophagogastric junction and positive
rotation of the Cartesian coordinate system. The right colored human
models explain the visual perspective of coronal multi-planar
reconstruction plane (green box). (B) Effect of “flex to the
left during anteflex” on transgastric mitral apparatus view: the left
ventricular outflow tract (LVOT) is revealed on the right side. The
generated view serves as surrogate image to estimate pressure gradient
at LVOT when transgastric LVOT views are not feasible. ALPM =anterolateral papillary muscle; AsAo = ascending aorta; AV= aortic valve; EG junction = esophagogastric junction; LA= left atrium; LAA = left atrial appendage; LPV = left
pulmonary vein; LV = left ventricle; LVOT = left
ventricular outflow tract; MDCT = multi-detector computed tomography;
MPA = main pulmonary artery; MPR = multi-planar reconstruction;
MV = mitral valve; PMPM = posteromedial papillary
muscle.
FIGURE 5 Mitral apparatus
Blue box: advance and anteflex of the trans-esophageal echocardiography
probe to obtain the transgastric left ventricle short-axis view (blue
arrow). Green box: Rotation of the multi-planar reconstruction (MPR)
line on the coronal MPR plane to obtain the transgastric 2-chamber view
for mitral apparatus (green arrow). ALPM = anterolateral papillary
muscle; DsAo = descending aorta; LA = left atrium; LAA = left
atrial appendage; LCX = left circumflex artery; LPV = left pulmonary
vein; LV = left ventricle; MV = mitral valve; PMPM = posteromedial
papillary muscle; RA = right atrium; RV = right ventricle.
FIGURE 6 Left ventricular outflow tract
UPPER: Standard deep transgastric 5-chamber view without rotation (0
degree). LOWER: Rotation at 135 degree: from computed tomography
orientation cube, we can easily understand the orientation is almost to
be that from anterior perspective. AML = anterior mitral leaflet; AsAo= ascending aorta; AV = aortic valve; LA = left atrium; LAA =
left atrial appendage; LV = left ventricle; LVOT = left
ventricular outflow tract; PA = pulmonary artery; RA = right atrium; RAA
= right atrial appendage; RV = right ventricle.
FIGURE 7 Tricuspid leaflets
Interatrial septum avoided at deep esophageal level (yellow box), and
tricuspid leaflets investigated without acoustic shadowing. Tricuspid
valve and its nearby orientations of nearby cardiac structures are
highly variable. As a result, preview with computed tomography
multi-planar reconstruction slices can help interventional sonographer
to understand better the spatial orientation during procedural
trans-esophageal echocardiography imaging. AsAo = ascending aorta; CS =
coronary sinus; DsAo = descending aorta; Eso = esophagus; EV =
Eustachian valve; IVC = inferior vena cava; LA = left atrium; LV = left
ventricle; MB = moderator band; PB = parietal band; RA = right atrium;
RCA = right coronary artery; RPV = right pulmonary vein; RV = right
ventricle.
FIGURE 8 Tricuspid apparatus
Papillary muscle of anterior tricuspid leaflet is continuous with MB.
Several small papillary muscles arising from the diaphragmatic right
ventricle wall support the posterior tricuspid leaflet. Ant = anterior
tricuspid leaflet; CT = chordae tendineae; D = diaphragmatic right
ventricle wall; MB = moderator band; PM = papillary muscle; Post =
posterior tricuspid leaflet; RA = right atrium; RV = right ventricle;
RVOT = right ventricular outflow tract.
FIGURE 9 Left atrial appendage, aortic valve and interatrial
septum
AsAo = ascending aorta; BAV = bicuspid aortic valve; CS = coronary
sinus; DsAo = descending aorta; FO = foramen ovale; IAS = interatrial
septum; IVC = inferior vena cava; LA = left atrium; LAA = left atrial
appendage; PA = pulmonary artery; Pec. m. = pectinate muscles; RA =
right atrium; RV = right ventricle; RVOT = right ventricular outflow
tract; SVC = superior vena cava; TV = tricuspid valve.