Biomedical subjects
Publications and source records attributed to Anthony Gallagher.
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OBJECTIVE: To study the relationship between performance on an endoscopic sinus surgery simulator (ES3) and fundamental perceptual, visuospatial, and psychomotor abilities. DESIGN: Validation study. SETTING: Tertiary care medical center. PARTICIPANTS: Thirty-four medical students and 4 otolaryngology residents voluntarily enrolled. INTERVENTIONS: Subjects performed tasks on the ES3, minimally invasive surgical trainer virtual reality (MIST-VR), pictorial surface orientation (PicSOr), and 3 visuospatial tests (cube comparison, card rotation, and map planning). MAIN OUTCOME MEASURES: The MIST-VR was scored for time, task error, economy of hand movement, economy of diathermy, and total score. Scores were generated for the PicSOr task and visuospatial tests. Scores were correlated with time, accuracy, and total subscore on navigation, injection, and dissection tasks, as well as hazard score and total trial score on the ES3. RESULTS: The PicSOr score was statistically significantly correlated with the hazard score on the ES3 (r = 0.50, P < .001). Cube comparison (r = 0.43, P < .01) and card rotation (r = 0.45, P < .01) scores correlated significantly with the ES3 trial score, as did the MIST-VR total score and the ES3 trial score (r = 0.57, P < .001). In a multiple regression model, the PicSOr, cube comparison, and MIST-VR total scores were statistically significant predictors of ES3 performance (r = 0.63, P < .01). CONCLUSIONS: Scores on the ES3 correlate strongly with scores on previously validated measures of perceptual, visuospatial, and psychomotor performance. The ES3 provides a reliable assessment of factors that are important to the acquisition of minimally invasive surgical skills, demonstrating construct validity.
We investigated right and left heart function in 51 patients with a body mass index of >35 kg/m(2) who underwent evaluation for gastric bypass surgery using standard Doppler echocardiography and color tissue Doppler imaging. Left atrial diameter (3.7 +/- 0.5 vs 3.3 +/- 0.4 cm, p <0.001), left ventricular end-diastolic diameter (5.0 +/- 0.6 vs 4.5 +/- 0.4 cm, p <0.001), and left ventricular mass index (119 +/- 49 vs 76 +/- 26 g/m, p <0.001) were increased in patients with severe obesity. Early diastolic mitral annular velocity (7.5 +/- 2.1 vs 9.6 +/- 3.0 cm/s, p <0.001), early diastolic/late diastolic mitral annular velocity ratio (1.38 +/- 0.6 vs 1.94 +/- 1.3, p = 0.007), early diastolic tricuspid annular velocity (7.8 +/- 2.6 vs 9.5 +/- 2.4 cm/s, p = 0.002), early diastolic/late diastolic tricuspid annular velocity ratio (0.9 +/- 0.36 vs 1.1 +/- 0.4, p = 0.048), and mitral annular systolic velocity (5.7 +/- 1.3 vs 6.5 +/- 1.5 cm/s, p = 0.012) were significantly lower in obese patients. Early diastolic mitral inflow/mitral annular velocity ratio was increased in the obese (13.5 +/- 4.7 vs 9.1 +/- 3.6, p <0.001). Tricuspid annular systolic velocities did not differ.
BACKGROUND: Many aspects of medical training take place on real patients in a live environment thus incurring risk. Apart from the obvious risks to patients there is the issue of X-ray exposure to both staff and trainees. Image quality used during interventional procedures is low to ensure minimum X-ray radiation dose. A virtual interventional system may be used to simulate the interventional cardiology training environment therefore reducing overall risk. The purpose of this project was to determine the appropriate image quality settings on a virtual training system to accurately simulate interventional cardiology and increase the face validity of the overall system. METHODS: Real image data was obtained from patients undergoing diagnostic interventional cardiology examinations in the Royal Victoria Hospital, Belfast. The images were obtained during catheter placement and contrast enhancement around the region of the heart. The diagnostic views were left anterior oblique, right anterior oblique, left lateral, caudal and the spider view. These five views were simulated on a virtual interventional training system (VIST, Mentice Medical Simulation AB, Sweden) by adjusting x-ray tube and table position at 20 different image quality settings. Signal to noise ratio and image contrast were measured for each of these views using soft tissue and vertebra. The results from the real image data and the VIST image data were compared. Calibration curves were compiled to determine the appropriate VIST image quality setting for each procedure. RESULTS: Average SNR ranged from 2.94 to 74.0 and IC ranged from 0.009 to 0.61 on the real image data. This indicates the very wide range of image quality encountered in interventional cardiology. Calibration curves for each view with the corresponding range of real patient image quality were produced. These calibration curves enabled the appropriate VIST image quality setting to be determined and therefore simulate the real examination image quality as closely as possible. CONCLUSIONS: The VIST system has been calibrated in terms of image quality for interventional cardiology examinations. This has increased the face validity of the system.
We describe a case of noncompaction of the ventricular myocardium diagnosed in the preoperative evaluation of a patient undergoing renal transplantation. Ventricular noncompaction is characterized by numerous prominent trabecular recesses with intratrabecular blood from the ventricular cavity. Color Doppler was suggestive of intramyocardial flow. With contrast-enhanced echocardiography the endocardial borders were clearly demarcated, allowing for visualization of trabecular recesses and intratrabecular flow. Contrast-enhanced echocardiography facilitates the diagnosis of noncompaction of the ventricular myocardium, circumventing the need for invasive diagnostic testing.