Ventures in education: a pipeline to medical education for minority and economically disadvantaged students.

BACKGROUND: Ventures in Education is an independent, nonprofit educational organization established by the Josiah H. Macy, Jr. Foundation to improve the academic achievement of minority and economically disadvantaged students, particularly in science and mathematics. One specific objective has been to increase the number of students who enter schools of the health professions, in particular schools of medicine, which was the focus of this study. METHOD: A search was conducted of the Association of American Medical Colleges' (AAMC's) Student and Applicant Information Management System database, to determine whether any of the 981 graduates in the first five Venture classes (1985 to 1989) of the original five New York City high schools in the program had pursued medical education. RESULTS: The search located 160 of the 981 Ventures graduates, and, of those, 136 had taken the Medical College Admission Test (13.9%), 109 (11.1%) has applied to medical school, 75 (7.6%) had been accepted, and 72 (7.3%) had matriculated into medical school. All of these percentages were significantly higher than the corresponding percentages for the general population. CONCLUSION: The findings have important implications for the AAMC's Project 3000 by 2000, showing that a rigorous academic curriculum with resources for individualized attention can facilitate the entry of minority and economically disadvantage students into medical education, with at least 7.3% of the Ventures graduates entering medical school and nearly 70% of those applying subsequently being accepted.

A novel ultrasonic technique for differentiating cysts from solid lesions: preliminary results in the breast.

The feasibility of a new ultrasonic technique to distinguish cysts from solid lesions is explored. High intensity pulses are used to induce acoustic streaming in cyst fluid, and this motion is detected using Doppler techniques. Acoustic streaming cannot be generated in solid lesions, therefore, its detection would indicate a cyst. In six of seven breast cysts motion was clearly generated and detected in vivo. Ultrasonic pulses with intensities up to 4.4 W cm-2 (I(spta) in water) were focused on the cysts for 10 s. Lesion diameters ranged from 0.6 to 2.5 cm; induced flow velocities were less than 4.0 cm s-1.

Real-time system for angle-independent US of blood flow in two dimensions: initial results.

The authors developed an ultrasound system that enables the speckle patterns produced by echoes from moving blood to be tracked in real time. Unlike current color Doppler flow imagers, this system allows the measurement of blood velocities in any direction within the imaging plane. The authors used this device to image flow in the human jugular vein and contrasted the image with one obtained under similar circumstances with color Doppler flow imaging. The authors demonstrated that this system can display in vivo lateral blood flow in real time. Further development of the system, including the incorporation of wall filters to enhance weak blood echoes and parallel techniques to reduce data acquisition time, will allow clinical imaging of flow with velocities of several meters per second in any direction without aliasing or dependence on the Doppler angle.

A real time system for quantifying and displaying two-dimensional velocities using ultrasound.

This paper describes a system that has been developed for measuring two-dimensional velocities in real time using ultrasound. The instrument tracks interframe speckle pattern motion using a Sum-Absolute-Difference (SAD) algorithm in order to produce a vector map of 2D velocities. The system's parallel architecture allows calculation of approximately 20,000 vectors per second using the current tracking geometry. A programmable graphics processor encodes individual velocity vectors with color and displays them superimposed on the B-mode image in real time. In vitro tests indicate that the system can track velocities well over the Doppler aliasing limit in any direction in the scan plane with greater than 94% accuracy. A color encoded image obtained from a flow phantom highlights the system's ability to display lateral motion with uniform coloration, in contrast to the two-color display of current ultrasonic Doppler instruments.

A frequency diversity process for speckle reduction in real-time ultrasonic images.

A pair of concurrent real-time B-mode image lines has been formed using a parallel processing system. In this system a wideband received echo is partitioned by a frequency diversity process and separate image lines are formed. Due to their differing constituent frequencies, these image lines have decorrelated speckle patterns. Upon averaging these filtered lines, the amount of speckle in the resultant displayed image is reduced. The reduction in image speckle and its accompanying improvement in perceived resolution is accomplished with no sacrifice of temporal resolution or real-time format. The effects of filter separation and filter quality factor (Q) are investigated through statistical analysis of images containing speckle-producing targets. A measurable improvement in image signal-to-noise ratio has been achieved.