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.

Correlation Between Transhepatic and Subcostal Inferior Vena Cava Views to Assess Inferior Vena Cava Variation: A Pilot Study.

OBJECTIVES: To assess the feasibility and reliability of transthoracic echocardiography to measure inferior vena cava (IVC) diameter variation using a transhepatic view. DESIGN: Prospective cohort study. SETTING: Single-center hospital. PATIENTS: Forty consecutive patients undergoing elective cardiac surgery. INTERVENTIONS: Bedside transthoracic echocardiography. MEASUREMENTS AND MAIN RESULTS: Correlation between the two views was measured using Pearson R, while agreement was measured using the intraclass correlation coefficient (ICC). In a nested sub-study of 16 randomly selected participants, all images were re-rated by the same rater, who was blinded to the original measurement results, and by a second blinded operator. Correlation between the subcostal and transhepatic views was moderate when assessing maximum (R 0.46; 95% confidence interval [CI], 0.18-0.68), and minimum (R 0.55; CI, 0.29-0.74) IVC diameter. Correlation when measuring IVC diameter variation was higher (R 0.70; CI, 0.49-0.83). Agreement between the two views for IVC diameter variation measurement was substantial (ICC 0.73; CI, 0.49-0.85). Intra-rater reliability was excellent (ICC 0.95-0.99). CONCLUSIONS: Agreement between subcostal and transhepatic views was substantial for the assessment of IVC diameter variation; however, the magnitude of agreement was less than anticipated. Further research is needed to determine if the transhepatic view can be used reliably in the assessment of fluid responsiveness.