Evaluation of a Patient-Specific, Low-Cost, 3-Dimensional-Printed Transesophageal Echocardiography Human Heart Phantom.

OBJECTIVE: Currently available 3-dimensional (3D) modeling and printing techniques allow for the creation of patient-specific models based on 3D medical imaging data. The authors hypothesized that a low-cost, patient-specific, cardiac computed tomography-based phantom, created using desktop 3D printing and casting, would have comparable image quality, accuracy, and usability to an existing commercially available echocardiographic phantom. DESIGN: Blinded comparative study. SETTING: Simulation laboratory at a single academic institution. PARTICIPANTS: Voluntary cardiac anesthesiologists at a single academic institution. INTERVENTIONS: Stage 1 of the study consisted of an online questionnaire in which a set of basic transesophageal echocardiography (TEE) views obtained from the 3D printed phantom and commercial phantom were presented to participants, who had to identify the views and evaluate their fidelity to clinical images on a Likert scale. In stage 2, participants performed an unblinded basic TEE examination on both phantoms. MEASUREMENTS AND MAIN RESULTS: The time needed to acquire each basic view was recorded. Overall usability of the phantoms was assessed through a questionnaire. The participants could recognize most of the views. Fidelity ratings for both phantoms were similar (p < 0.05), with the exception of a midesophageal 2-chamber view that was observed better on the 3D printed phantom. The time required to obtain the views was shorter for the 3D printed phantom, although not statistically significant for most views. The overall user experience was better for the 3D phantom for all categories examined (p < 0.05). CONCLUSIONS: The study suggested that a 3D-printed TEE phantom is comparable with the commercially available one with good usability.

Validation of Quantitative 3-Dimensional Transesophageal Echocardiography Mitral Valve Analysis Using Stereoscopic Display.

OBJECTIVE: The use of 3-dimensional (3D) transesophageal echocardiography (TEE) in perioperative evaluation of the mitral valve (MV) is increasing progressively, including the use of 3D MV models for quantitative analysis. However, the use of 3D MV models in clinical practice still is limited by the need for specific training and the long time required for analysis. A new stereoscopic visualization tool (EchoPixel True 3D) allows virtual examination of anatomic structures in the clinical setting, but its accuracy and feasibility for intraoperative use is unknown. The aim of this study was to assess the feasibility of 3D holographic display and evaluate 3D quantitative measurements on a volumetric MV image using the EchoPixel system compared with the 3D MV model generated by QLAB Mitral Valve Navigation (MVN) software. DESIGN: This was a retrospective comparative study. SETTING: The study took place in a tertiary care center. PARTICIPANTS: A total of 40 patients, 20 with severe mitral regurgitation who underwent mitral valve repair and 20 controls with normal MV, were enrolled retrospectively. INTERVENTIONS: The 3D-TEE datasets of the MV were analyzed using a 3D MV model and stereoscopic display. The agreement of measurements, intraobserver and interobserver variability, and time for analysis were assessed. MEASUREMENTS AND MAIN RESULTS: Fair agreement between the 2 software systems was found for annular circumference and area in pathologic valves, but good agreement was reported for prolapse height and linear annular diameters. A higher agreement for all annular parameters and prolapse height was seen in normal valves. Excellent intraobserver and interobserver reliability was proved for the same parameters; time for analysis between the 2 methods in pathologic valves was substantially equivalent, although longer in pathologic valves when compared with normal MV using both tools. CONCLUSION: EchoPixel proved to be reliable to display 3D TEE datasets and accurate for direct linear measurement of both MV annular sizes and prolapse height compared to QLAB MVN software; it also carries a low interobserver and intraobserver variability for most measurements.

Low-cost three-dimensional printed phantom for neuraxial anesthesia training: Development and comparison to a commercial model.

METHODS: Anonymized CT DICOM data was segmented to create a 3D model of the lumbar spine. The 3D model was modified, placed inside a digitally designed housing unit and fabricated on a desktop 3D printer using polylactic acid (PLA) filament. The model was filled with an echogenic solution of gelatin with psyllium fiber. Twenty-two staff anesthesiologists performed a spinal and epidural on the 3D printed simulator and a commercially available Simulab phantom. Participants evaluated the tactile and ultrasound imaging fidelity of both phantoms via Likert-scale questionnaire. RESULTS: The 3D printed neuraxial phantom cost $13 to print and required 25 hours of non-supervised printing and 2 hours of assembly time. The 3D printed phantom was found to be less realistic to surface palpation than the Simulab phantom due to fragility of the silicone but had significantly better fidelity for loss of resistance, dural puncture and ultrasound imaging than the Simulab phantom. CONCLUSION: Low-cost neuraxial phantoms with fidelity comparable to commercial models can be produced using CT data and low-cost infrastructure consisting of FLOS software and desktop 3D printers.

Description of a Novel Set-up for Functional Echocardiographic Assessment of Left Ventricular Performance During Ex Vivo Heart Perfusion.

Ex vivo heart perfusion (EVHP) is a new technology aimed at decreasing cold ischemia time and evaluating cardiac function before transplanting a donor heart. In an experimental EVHP swine model, we tested a 3D-printed custom-made set-up to perform surface echocardiography on an isolated beating heart during left ventricular loading. The views obtained at any time point were equivalent to standard transesophageal and transthoracic views. A decrease in left ventricular function during EVHP was observed in all experiments.