Perioperative 3D transoesophageal echocardiography. Part 2: clinical applications

Figures

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  Fig 1. Three-dimensional transoesophageal echocardiography en face view of the MV. (A) Shows a pathologic MV with Barlow's disease, bileaflet prolapse, a coaptation gap, a flail of the A2 segment of the AMVL, and a ruptured chorda tendinae flicking in and out of the LA. The valve appears in mid systole from the standard surgical en face view from the LA perspective with the AoV in the 12 o'clock position. It uses a standard 3D render where brown shading is closer and blue shading is further from the viewer. (B) Shows part (A) but with tissue-like rendering and 3D ray tracing to simulate a light source. The ‘shadow’ generated by placement of the light source makes the ruptured chordae and prolapsed leaflet more easily discernible. (C) The tissue is translucent, so-called ‘glass’ rendering, aiding identification of the MR jet origin. AoV, aortic valve; AMVL, anterior mitral valve leaflet; CFD, colour flow Doppler; LA, left atrium; MR, mitral regurgitation; MV, mitral valve; PMVL, posterior mitral valve leaflet.

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  Fig 2. Three-dimensional transoesophageal echocardiography views of the AoV. (A) This is a diagram of the AoV and aortic root in the long axis. The geometric height, coaptation height and effective height are all measurements highlighted by coloured lines with average normal values.12,23 (B) This shows a 3D short axis view of the AoV looking from the aorta, the recommended orientation as per ASE guidelines. Anatomic structures are labelled on the right. Three dotted lines show planes through the centre of each cusp body and the opposing commissure in diastole. These planes guide the measurements discussed in part A. (C) This shows the measurement of the geometric height of the NCC using MPR. The AoV appears in diastole in short axis in the green box, with the red plane then aligned across the NCC body and opposing commisure. The red box shows a tracing of the geometric height of the NCC. The blue plane/box is not used. AoV, aortic valve; IAS, intra-atrial septum; LA, left atrium; LCC, left coronary cusp; LVOT, left ventricular outflow tract; MPR, multi-plane reconstruction; NCC, non-coronary cusp; RA, right atrium; RCC, right coronary cusp.

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  Fig 3. Three-dimensional transoesophageal echocardiography views of the TV. (A) This is a 3D image of the TV in diastole in a short axis orientation from the RA perspective as per the ASE guidelines. The labels of important anatomic structures are in yellow. (B) Shows part (A) (as grey scale) but with CFD superimposed showing a TR jet. (C) This shows MPR of the TV annulus. The green box is an MPR-derived 2D plane resembling the standard mid-oesophageal RV-focussed view used to measure TV annulus, as shown by the yellow line and measurement. Placing the red MPR plane across shows the valve and the annulus in the red box, with the annulus highlighted by the pink dotted line. Note these measurements are significantly different, as the 2D plane may not capture the annulus at its widest point. The yellow plane is shown in the MPR reconstruction, illustrating why 2D-TOE measurements may under-estimate annular diameter when they are not aligned at the widest point. Note also the annulus is oval and may dilate asymmetrically (see main text). (D) This shows bi-plane imaging to guide a catheter mounted clip across the TV. Note the two planes are not perpendicular (as is default) but have been…

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  Fig 4. Three-dimensional transoesophageal echocardiography views of the left ventricle. (A) This is a full volume acquisition of the LV using multi-beat acquisition over 4-beats at a frame rate of 27 Hz. (B) This shows a 3D volumetric model of the LV, from tracking of the endocardial border across the cardiac cycle. Myocardial segments are colour coded. Calculation of EF without geometric assumptions occurs from this dataset. (C) Reconstruction of the left ventricular full volume acquisition can show multiple short axis planes across the ventricle. This aids in identification of RWMA. The planes, numbered 1–9, correspond to those seen in the machine display shown in part (D). (D) Multiple short-axis slices of the LV reconstructed from the full volume dataset. Three MPR planes seen in green, red and yellow planes on the left are aligned across the left ventricular cavity. Aligning the blue dotted lines between the base and apex delineates the position of the first and last short axis slices seen on the right. The addition of numbers aids understanding when viewed with part (C). A, anterior wall of left ventricle; EDV, end-diastolic volume; EF, ejection fraction; ESV, end-systolic volume;…

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  Figure S1. MV en face view. This summarises the directions to obtain the surgical en face view of the MV. Specific steps vary between different platforms but are broadly similar. Abbreviations: AoV, aortic valve; CFD, colour flow Doppler; LA, left atrium; MV, mitral valve.

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  Figure S2. Parametric MV models. (A) This is a dynamic Siemens (Erlangen, Germany) model of the MV, which overlies the 3D full volume dataset and integrates CFD across the entire cardiac cycle. (B) This is a dynamic MV model during systole analysed using TomTec (Munich, Germany) software. (C) This shows a static mid-systole Philips (Amsterdam, Netherlands) MV model, identifying scallops on both leaflets and the coaptation line. Each software automatically derives and displays indices for these models. Abbreviations: CFD, colour flow Doppler; MV, mitral valve.

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  Figure S3. Carpentier classification of MR. Category I is MR with normal leaflet motion, typically from clefts or perforation. The example shows a colour jet that is not originating from the coaptation line. The 3D en-face view shows a perforation in the anterior MV leaflet near the annulus (red circle). Category II is MR with excessive leaflet motion. The example shows posterior leaflet prolapse in the 2D view, although it is unclear which segment is involved. The 3D en-face view highlights a flail P2 segment. Category IIIa is leaflet restriction in systole and diastole, often caused by calcific or rheumatic valves. The 2D image shows a thickened rheumatic valve, also seen in the 3D en-face view in diastole. Category IIIb is restriction in systole only from LV ischaemia, leading to annular dilatation or RWMA that tether the chordae tendinae. Abbreviations: MV, mitral valve; MR, mitral regurgitation; RWMA, regional wall motion abnormalities.

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  Figure S4. Measuring VCA using MPR. As described in the main text, VCA measurements can estimate MR severity. The 2D image in the green box derives from the 3D dataset and resembles a conventional 2D mid-oesophageal 4 chamber view of the MV. The red box is a 2D plane perpendicular to the green. Both planes align across the MR jet orifice. The blue plane aligns perpendicular to both the red and green planes at the level of the RO. The RO appears in short axis in the blue box and traced using planimetry to yield the VCA of 4.10 cm2 (see white dotted line in blue box). Note that in this example, there is a second MR jet seen in both the red and blue panels that is not being measured. 3D-TOE can help in isolation and measurement of multiple jets like this, which can be challenging with 2D imaging alone. Abbreviations: AMVL, anterior mitral valve leaflet; MPR, multiplane reconstruction; MR, mitral regurgitation; MV, mitral valve; PMVL, posterior mitral valve leaflet; RO, regurgitant orifice; VCA, vena contracta area.

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  Figure S5. Measuring aortic root dimensions using MPR. In this aneurysmal aortic root, MPR is used to align two perpendicular planes accurately across the AoV annulus in mid-systole. The green box shows a short axis view of the AoV, which is used to align the red plane across the LCC/NCC commissure and through the mid body of the RCC. The red box displays this plane, which is a correctly aligned long-axis view of the aortic root, allowing accurate measurement of the aortic annulus in this orientation. The blue plane aligns through the NCC and LCC bodies, which is a non-standard orientation but can assess distortion of the root caused by an aneurysm. Note that the annular dimensions of 2.88 cm and 2.57 cm are markedly different. A similar assessment of the root at the level of the sinuses of Valsalva and sinotubular junction is possible. Abbreviations: AoV, aortic valve; LCC, left coronary cusp; MPR, multi-plane reconstruction; NCC, non-coronary cusp; RCC, right coronary cusp.

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  Figure S6. Measuring aortic valve area using MPR and planimetry. The red box shows an MPR-derived imaging plane similar to a 2D AoV long-axis view. Following identification of the leaflet tips in mid-systole, perpendicular alignment of the green imaging plane in the red box occurs at the AoV leaflet tips. The valve orifice appears in the green box and traced using planimetry (see white dotted line). The blue box/plane is not used here. Abbreviations: AoV, aortic valve; MPR, multiplane reconstruction.

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  Figure S7. 3D-TOE of the PV. (A) This shows a 3D rendered view of the PV from the MPA perspective with labelled leaflets. (B) Biplane imaging at 65° and 155° shows the PV from the upper oesophageal view. (C) This is a 3D image of a stenotic PV from the same vantage point as part A. (D) This is the 2D mid-oesophageal aorta short axis view of the same stenotic PV in part C. Abbreviations: A, anterior leaflet of PV; L, left leaflet of PV; MPA, main pulmonary artery; PV, pulmonary valve; R right leaflet of PV.

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  Figure S8. 3D-TOE acquisition of the RV. (A) This shows a single beat 3D full volume acquisition of the RV, obtained from an RV focussed mid-oesophageal 4 chamber view. The volume dimensions contain the entire RV, including the RV outflow tract. (B) This is a dynamic wire-frame model of the RV endocardial border using offline processing by TomTec (Munich, Germany) software. The RV has a complex shape with the software automatically measuring ejection fraction and helping to identify RWMA. Abbreviations: RV, right ventricle; RWMA, regional wall motion abnormalities.