Multiplane Transthoracic Echocardiography: Image Orientation, Anatomic Correlation, and Clinical Experience with a Prototype Phased Array Multiplane Surface Probe

Multiplane transthoracic echocardiography provides numerous sequential images by rotation of the transducer imaging array through 180° with the surface probe at a fixed site. We explored the potential of this new technique with a 3.7/5-MHz prototype multiplane transthoracic probe. Echoanatomic correlations were first examined in ten explanted hearts. The transducer was then applied in 30 normal humans at transthoracic acoustic windows to determine the imaging planes available. Use of this probe in 76 patients with various cardiac disorders indicated that this probe eases the procedure of transthoracic echocardiographic examination, provides incremental information for improved delineation and understanding of cardiac pathology, and yields many novel insights to echocardiographic interpretation. Multiplane transthoracic echocardiography appears to expand the versatility of transthoracic two-dimensional echocardiography.     

Variomatrix--a newly developed transesophageal echocardiography probe with a rotating matrix biplane transducer. Technological aspects and initial clinical experience

The recently developed multiplane transesophageal echocardiography (TEE) probes cannot provide real-time synchronous biplane imaging. We have developed a new "Variomatrix" probe that combines the advantages of the rotating mechanism of the multiplane probe with the capability of providing simultaneous, side-by-side imaging. Its advantages are: (1) easy manipulation to obtain the optimal planes; (2) avoidance of excessive movement of the probe inside the esophagus; (3) assessment of oblique planes that are not viewed with the usual biplane probe; (4) better understanding of the continuity of structures by the simultaneous, side-by-side biplane, rotating images, providing clearer three-dimensional conception; and (5) shorter examination time by providing a 180 degrees imaging range by rotating the transducer just 90 degrees .     

Pediatric Transesophageal Echocardiography by Means of a Miniature 5-MHz Multiplane Transducer

The development of a miniature multiplane transesophageal echocardiographic (TEE) transducer for pediatric use is the latest development in TEE. Horizontal, longitudinal, and all possible intermediate oblique planes can be obtained with minimal transducer manipulation. We studied 48 patients with an experimental 5-MHz transducer, which contains 48 transmitting elements. The dimensions of the tip are 27 × 10.6 × 7.9 mm. Patients ages ranged from 2 days to 16 years, their weights from 3.6–67 kg. Multiplane TEE proved to be complementary to the single horizontal plane in assessing the right ventricular outflow tract, the left ventricular outflow tract, ascending aorta, the atrial septum, the atrioventricular (AV) valves, especially in AV septal defects, and double inlet left ventricle (DILV). Moreover, multiplane TEE was extremely helpful in judging the outflow tracts and ventricular septal defects in more complex heart defects such as DILV, double outlet right ventricle, and hearts with discordant connections. Multiplane TEE offered superb monitoring of cardiac interventions. We conclude that multiplane TEE provides new imaging planes and enables visualization of every major structure of the heart by unlimited scan planes. Multiplane TEE is indispensable in congenital heart defects. Thus, multiplane TEE adds to diagnostic assurance and enhances decision making for surgery.     

Three-dimensional and four-dimensional transesophageal echocardiographic imaging of the heart and aorta in humans using a computed tomographic imaging probe

We evaluated the clinical applicability of a prototype tomographic transesophageal echocardiographic (TEE) system, which not only provides conventional TEE images but also three-dimensional tissue reconstruction and four-dimensional display capabilities. The probe was used in 16 patients in the echocardiographic laboratory, intensive care unit, and the operating room. The instrument is a 5-MHz, 64-element, phased array unit mounted on a sliding carriage within a casing. After appropriate probe placement within the esophagus, the probe is straightened, a balloon surrounding the probe is inflated, and data acquisition begun with ECG and respiration gating. With computer controlled transducer movement at 1-mm increments, a complete cardiac cycle is recorded at each tomographic level. These are processed using a dedicated four-dimensional software, and displayed as a dynamic three-dimensional tissue image of the heart. We were able to see the dynamic motion of the ventricles and all the valves in the four-dimensional format. In addition to four-dimensional display, we were able to cut and visualize the heart in dynamic mode in any desired plane and also in multiple planes. Patients tolerated the procedure well. We conclude that this tomographic four-dimensional approach, which does not require tedious off-line processing, can easily be performed in patients and has a strong clinical potential.     

The initial clinical evaluation of a transesophageal system with pulsed Doppler, continuous wave Doppler, and color flow imaging based on an annular array technology

The application of transesophageal echocardiography (TEE) offers access to a great deal of important clinical information regarding cardiovascular anatomy and physiology. Two applications which have not been reported and would appear to be of interest are continuous wave Doppler capabilities and the implementation of higher frequency transducers. A TEE system designed at the Institute of Biomedical Engineering in Trondheim, which is based on an annular array technology, offers these capabilities. We evaluated this instrument in the clinical setting in a series of 30 patients to test the probe function in terms of the tissue and flow imaging quality with a 7.5 MHz carrier frequency, and to report on the implementation of a continuous wave Doppler modality in a TEE probe. We found that the annular array method permitted the use of high frequency probes for tissue and flow imaging which resulted in excellent image resolution, and that shifting the carrier frequency of the transducer to a lower frequency permitted the optimization of the Doppler sensitivity. The continuous wave Doppler was used to measure abnormal blood flow velocities in excess of 5.0m/s, and was particularly useful in the operating room as velocity measurements could be obtained without compromising the sterile field. The results of our evaluation indicate that high imaging frequencies and continuous wave Doppler can be applied by an annular array TEE transducer.     

Panoramic transesophageal echocardiography. Clinical application of real-time, wide-angle, transesophageal two-dimensional echocardiography and color flow imaging

Panoramic transesophageal echocardiography is a new development in transesophageal echocardiography (TEE) technology, which yields a wide-angle imaging field for real-time two-dimensional and color flow imaging. We report our early experience in patients with the use of an annular-array TEE probe that provides a wide, 270 degrees angle imaging field for two-dimensional echocardiographic imaging. The field of view can, however, be narrowed to 15 degrees . The field of view for color flow imaging can be varied from 180 degrees to 10 degrees . Pulsed-Doppler recordings of flow velocity are also possible. This TEE system provides a panoramic vision of cardiac and paracardiac structures from the esophagus and stomach. Besides cardiovascular structures, other thoracic and upper abdominal organs can be visualized. The wide field of view allows a better comprehension of the cardiac anatomy and its relationship with adjacent structures. The initial experience suggests that this method, besides providing the usually required diagnostic information, may have a number of additional applications. Its clinical potential and directions for future developments are reviewed.     

Multiplane Transesophageal Echocardiographic Evaluation of Defects of the Atrioventricular Septum: The Crux of the Matter

The availability of multiplane transesophageal probes has dramatically facilitated visualization of complex cardiac anatomy, with full dynamic tracking of anatomic contiguity. This report describes the unique applicability of multiplane transesophageal echocardiography (TEE) for visualization and assessment of a spectrum of congenital cardiac defects involving the cardiac crux, including the atrioventricular septum, inlet muscular septum, and the atrioventricular valves. With further evolution and progressive miniaturization of these probes, the use of this echocardiographic modality will hopefully encroach into the young infant age range, permitting enhanced preoperative and perioperative depiction of complex congenital cardiac anatomy.     

Clinical Determinations of Volumes of Normal and Aneurysmatic Left Ventricles by Three-Dimensional Transesophageal Echocardiography

Biplane methods of determining left ventricular volumes are inaccurate in the presence of aneurysmal distortions. Multiplane transesophageal echocardiography, which provides multiple, unobstructed cross-sectional views of the heart from a single, stable position, has the potential for more accurate determinations of volumes of irregular cavity forms than the biplane methods. The aim of the study was to determine the feasibility of three-dimensional measurements of ventricular volumes in patients with normal and aneurysmatic left ventricles by using multiplane transesophageal echocardiography. With the echotransducer in the mid-esophageal (transesophageal) position, nine echo cross-sectional images of the left ventricle in approximately 20 degrees angular increments were obtained from each of 29 patients with coronary artery disease who had undergone biplane ventriculography during diagnostic cardiac catheterization. In 17 of these 29 patients, echo cross-sectional images of the left ventricle with the echotransducer in transgastric position were also obtained. End-diastolic volume, end-systolic volume, and ejection fraction were determined from multiplane transesophageal echocardiographic images and biplane ventriculographic images by the disc-summation method and compared with each other. In another ten patients with indwelling pulmonary artery catheters, stroke volumes calculated from multiplane transesophageal echocardiographic images were compared with those derived from thermodilution cardiac output measurements. Correlations between biplane ventriculographic and multiplane transesophageal echocardiographic measurements were higher in the ten patients with normal ventricular shape [for end-diastolic volumes, r = 0.91, SEE = 19 ml; for end-systolic volumes, r = 0.98, SEE = 9.3 ml; for ejection fractions (EFs), r = 0.91, SEE = 5.4%] than in the 19 patients with ventricular aneurysms (for end-diastolic volumes, r = 0.61, SEE = 31.5 ml; for end-systolic volumes, r = 0.66, SEE = 32.5 ml; for EFs, r = 0.79, SEE = 8%). Correlations between echocardiographic volumes from the transesophageal and transgastric transducer positions were high independent of left ventricular geometry (for end-diastolic volumes, r = 0.84, SEE = 13.1 ml; for end-systolic volumes, r = 0.98, SEE = 9.6 ml; for EFs, r = 0.97, SEE = 3.4%). In 12 observations (4 normal and 8 aneurysmal) from the ten patients with indwelling pulmonary artery catheters, correlation between stroke volumes determined from thermodilution cardiac output measurements and those derived from multiplane transesophageal echocardiographic images was high (r = 0.91, SEE = 6 ml). The results indicate that three-dimensional measurements of volumes of irregular and distorted left ventricles are feasible with multiplane transesophageal echocardiography. This method may be more accurate than biplane methods, especially in the presence of left ventricular aneurysms.     

Live/Real Time Three-Dimensional Transesophageal Echocardiography

Since the advent of matrix array transducer, three-dimensional transesophageal echocardiography has come to frequent clinical use. It has significantly enhanced the communication between the operators and cardiac imagers in the operating room as well as in the cardiac interventional labs. This article reviews the history, technological aspects, and the protocol for acquisition and processing of the data sets. It also discusses its advantages in various clinical scenarios, both in diagnostic and therapeutic situations. It highlights its limitations in the current form and prospects of future development. (Echocardiography 2012;29:103-111)     

Eustachian valve endocarditis: Detection with multiplane transesophageal echocardiography

Right-sided involvement is fairly common in infective endocarditis, but involvement of the eustachian valve is distinctly rare. We present the case of a 36-year-old intravenous drug user with staphylococcal bacteremia and septic pulmonary emboli. Transthoracic echocardiography was normal, but transesophageal echocardiography revealed a large eustachian valve vegetation. This case illustrates the utility of multiplane transesophageal echocardiography in the evaluation of eustachian valve pathology.     

Transesophageal biplane echocardiographic imaging: technique, planes, and clinical usefulness

The technique of examination, imaging planes, and the clinical utility of transesophageal biplane echocardiography are described.     

Multiplane/3D transesophageal echocardiography monitoring to improve the safety and outcome of complex transvenous lead extractions

Both transesophageal echocardiography (TEE) and intracardiac echocardiography have been used to assist transvenous lead extractions. The clinical utility of continuous echocardiographic monitoring during the procedure is still debated, with different reports supporting opposite findings. In cases where the procedure is expected to be difficult, we propose adding a continuous TEE monitoring using a static 3D/multiplane probe in mid‐esophageal position, with digital remote manipulation of the field of view. This approach may improve the chances of a successful extraction, increase safety, or even guide the entire intervention. We present here a short case series where continuous monitoring by TEE played an important role.     

Transesophageal Echocardiographic Imaging for Congenital Lesions of the Left Ventricular Outflow Tract and the Aorta

A comprehensive transthoracic echocardiographic imaging is possible for most pediatric patients. However, for patients in whom accurate anatomical and physiological assessment is not possible, transesophageal echocardiography (TEE) provides a supplemental diagnostic modality. Imaging the left ventricular outflow tract and the aorta involves a complicated technique of rotation, flexion, and changes in the depth of the transesophageal probe because the areas of interrogation involve multiple planes within the thoracic cavity. Furthermore, the relationship between the esophagus and the cardiovascular structures changes at various levels of the thorax. Transesophageal probes having characteristics of frequency agility, all forms of Doppler capability, and a higher number of crystal elements are now available. Abnormalities of the subaortic area, the aortic valve, coronary arteries, and the entire thoracic aorta can be clearly demonstrated. TEE also has played a complementary role in diagnostic and interventional catheterization. It has become vital in the operating room for the preoperative definition of certain aspects of the anatomy and for immediate postoperative evaluation of the result of surgery.     

Transesophageal Color Doppler Three-Dimensional Echocardiographic Assessment of Left Circumflex Coronary Artery Fistula

We describe an adult patient with a left circumflex coronary artery fistula in whom color Doppler three-dimensional transesophageal echocardiography demonstrated clearly the exact site of the communication with the coronary sinus near the left atrial appendage. This could not be delineated definitively by multiplane two-dimensional transesophageal echocardiography.     

Biplane transesophageal echocardiography utilizing transverse and sagittal imaging planes: technique, echo-anatomic correlations, and display approaches

The recent development of biplane transesophageal probes equipped with both transverse plane and sagittal plane imaging transducers allows a more complete examination of cardiac and aortic anatomy than is possible with conventional single plane transesophageal instruments. While the imaging planes used in transverse plane transesophageal imaging have been standardized, several different approaches have been suggested for the orientation and display of the newer sagittal plane images. An accepted display convention for the transverse and sagittal plane images would ease interpretation of the multiple complex images obtained during the biplane transesophageal examination. In this article, the different transverse plane and sagittal plane echocardiographic images that may be acquired during the biplane transesophageal examination are described and correlated with cardiac anatomy. A method for image display orientation is suggested that is most consistent with that previously used for the single plane transesophageal examination.     

The Role of Multiplane Transesophageal Echocardiography in Diagnosing PDA in an Adult

The usefulness of multiplane transesophageal echocardiography in diagnosing PDA in asymptomatic adults is described.     

Traumatic Rupture of Atherosclerotic Plaque Producing Aortic Isthmus Dissection

Traumatic rupture of aortic isthmus atherosclerotic plaque resulting in dissection has not been documented through the use of either invasive or noninvasive diagnostic modalities. We describe an elderly patient in whom transesophageal echocardiography and three-dimensional reconstruction of multiplane transesophageal two-dimensional images clearly demonstrated the traumatic dissection to be due to rupture of a large atherosclerotic plaque located in the aortic isthmus. The patient had experienced blunt trauma to the chest from the impact of the steering wheel during an automobile accident.     

Use of the monoplane intracardiac imaging probe in high-risk infants during congenital heart surgery

Imaging options are limited in high‐risk infants with small or abnormal oropharyngeal anatomy during congenital heart surgery. Methods: All cases in which the monoplane intracardiac echo probe was used for transesophageal intraoperative imaging over a 15‐month period at a single institution were reviewed. Results: Eleven patients underwent intraoperative imaging using the intracardiac probe. Patient weight ranged from 1.96 kg to 4 kg. Adequate images of the anatomy relevant to the surgical repair were obtained in all cases. No adverse events related to probe use occurred. Conclusion: Transesophageal echocardiography using the monoplane intracardiac echo probe provides safe and effective imaging in patients who are not candidates for standard transesophageal echocardiography.     

Aortic Stenosis

Noninvasive assessment of aortic valve area by echocardiography has become the standard of practice over the past few years. The advent of transesophageal echocardiography (TEE) has provided a new method for the assessment of aortic valve area (AVA) using planimetry by two-dimensional imaging. Clear visualization of the anatomy of the valve, as well as accuracy of AVA assessment, makes TEE an invaluable tool for the evaluation of aortic valve stenosis. TEE is especially helpful in clinical settings when there is a discrepancy between the AVA obtained by transthoracic echocardiography and cardiac catheterization. TEE is particularly helpful in the assessment of the aortic valve during intraoperative echocardiography. This review discusses the techniques, imaging planes, and details for assessing AVA by TEE. The role of TEE in AVA assessment is described, with specific clinical case examples cited.     

Effect of performing real time three-dimensional transesophageal echocardiography in addition to two-dimensional transesophageal echocardiography on operator diagnostic confidence

Background: This study evaluates the effects of performing real time three‐dimensional transesophageal echocardiography in addition to conventional two‐dimensional transesophageal echocardiography on diagnostic confidence. Methods: Operator diagnostic confidence in addressing clinical questions posed by the referral was scored using a five‐point scale for two‐dimensional transesophageal echocardiography alone and the combination of two‐dimensional and real time three‐dimensional transesophageal echocardiography in 136 consecutive patients undergoing examination in an academic hospital. Results: Mean diagnostic confidence score was higher for the combined studies compared to two‐dimensional transesophageal echocardiography alone (4.5 vs. 4.1, P < 0.001)). The addition of real time three‐dimensional transesophageal echocardiography increased diagnostic confidence score in 45 (33.1%) patients, and the percentage of studies with total diagnostic confidence rose from 40.4% with two‐dimensional transesophageal echocardiography alone to 65.4% after performing real time three‐dimensional transesophageal echocardiography. Type of clinical indication was associated with improved score by the combined exams (P < 0.004). The addition of real time three‐dimensional transesophageal echocardiography was most likely to improve diagnostic confidence score in studies performed to assess valve disease (56.1%) and least likely in examinations performed for intracardiac infection (14.9%). The location (anterior or posterior) of the primary cardiac pathology was not associated with improved score by the combined studies (P = 0.498). Conclusions: The addition of real time three‐dimensional transesophageal echocardiography to two‐dimensional transesophageal echocardiography increases diagnostic confidence in examinations routinely performed in an academic practice. Further studies of the impact of real time three‐dimensional transesophageal echocardiography on patient management, outcomes and displacement of or need for downstream testing are warranted. (Echocardiography 2011;28:235‐242)