Empirical electro-optical and x-ray performance evaluation of CMOS active pixels sensor for low dose, high resolution x-ray medical imaging.

Monolithic complementary metal oxide semiconductor (CMOS) active pixel sensors with high performance have gained attention in the last few years in many scientific and space applications. In order to evaluate the increasing capabilities of this technology, in particular where low dose high resolution x-ray medical imaging is required, critical electro-optical and physical x-ray performance evaluation was determined. The electro-optical performance includes read noise, full well capacity, interacting quantum efficiency, and pixels cross talk. The x-ray performance, including x-ray sensitivity, modulation transfer function, noise power spectrum, and detection quantum efficiency, has been evaluated in the mammographic energy range. The sensor is a 525 x 525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25 x 25 microm pixel pitch. Reading at 10 f/s, it is found that the sensor has 114 electrons total additive noise, 10(5) electrons full well capacity with shot noise limited operation, and 34% interacting quantum efficiency at 530 nm. Two different structured CsI:Tl phosphors with thickness 95 and 115 microm, respectively, have been optically coupled via a fiber optic plate to the array resulting in two different system configurations. The sensitivity of the two different system configurations was 43 and 47 electrons per x-ray incident on the sensor. The MTF at 10% of the two different system configurations was 9.5 and 9 cycles/mm with detective quantum efficiency of 0.45 and 0.48, respectively, close to zero frequency at approximately 0.44 microC/kg (1.72 mR) detector entrance exposure. The detector was quantum limited at low spatial frequencies and its performance was comparable with high resolution a: Si and charge coupled device based x-ray imagers. The detector also demonstrates almost an order of magnitude lower noise than active matrix flat panel imagers. The results suggest that CMOS active pixel sensors when coupled to structured CsI:Tl can be used for conventional and advanced digital mammography due to their low noise, high resolution performance.

Ultra-wide bore 900 MHz high-resolution NMR at the National High Magnetic Field Laboratory.

Access to an ultra-wide bore (105 mm) 21.1 T magnet makes possible numerous advances in NMR spectroscopy and MR imaging, as well as novel applications. This magnet was developed, designed, manufactured and tested at the National High Magnetic Field Laboratory and on July 21, 2004 it was energized to 21.1 T. Commercial and unique homebuilt probes, along with a standard commercial NMR console have been installed and tested with many science applications to develop this spectrometer as a user facility. Solution NMR of membrane proteins with enhanced resolution, new pulse sequences for solid state NMR taking advantage of narrowed proton linewidths, and enhanced spatial resolution and contrast leading to improved animal imaging have been documented. In addition, it is demonstrated that spectroscopy of single site (17)O labeled macromolecules in a hydrated lipid bilayer environment can be recorded in a remarkably short period of time. (17)O spectra of aligned samples show the potential for using this data for orientational restraints and for characterizing unique details of cation binding properties to ion channels. The success of this NHMFL magnet illustrates the potential for using a similar magnet design as an outsert for high temperature superconducting insert coils to achieve an NMR magnet with a field >25 T.

A collaborative clerkship with a focus on rural community health.

The Deans' Rural Primary Care Clerkship was developed through the collaborative efforts of South Carolina's two medical schools. The clerkship provides students an innovative learning experience in rural community medicine through the unique combination of learning opportunities with community-oriented primary care, continuous quality improvement, interdisciplinary health care teams, and cultural competency. Much of students' learning addresses current directives for population health training. The positive experience students are having in these rural, underserved South Carolina communities will help them better understand the rewards and challenges of rural, community-responsive health care.

Medical students' abilities to take an occupational history: use of the WHACS mnemonic.

This study examined medical students' use of the WHACS mnemonic during an occupational history objective structured clinical examination station. Students' performance on the 10 content-specific station items was calculated. Factor analysis of the items was conducted, and student demographic and academic characteristics associated with performance on the station were examined. A total of 205 students completed the station. The mean number of correct responses was 5 (SD, 1.6). Students performed well on some items and less well on others. Factor analysis supported the WHACS framework. There were no significant associations with student demographic or academic characteristics. Students were aware of the particular features of an occupational history but were deficient in other areas; this awareness was not related to demographic or academic characteristics. The WHACS mnemonic could be an effective tool to teach occupational history-taking skills.

The ability of a medical school admission process to predict clinical performance and patients' satisfaction.

PURPOSE: The authors evaluated the ability of a two-step admission process to predict clinical performance and patients' satisfaction on a third-year objective structured clinical examination (OSCE). METHOD: Subjects were three matriculating classes (1993, 1994, 1995) at one medical school. Data for the classes were analyzed separately. Independent variables were the Academic Profile (AP), an initial ranking of applicants based on grade-point ratio and MCAT scores, and the Selection Profile (SeP), an average of three interview scores. Interviews were offered based on AP rank, and admission was offered based on SeP rank. Dependent variables were total score on the faculty-graded portion of the OSCE and patients' satisfaction scores completed by the OSCE standardized patients. The authors evaluated the correlations between AP and OSCE performance and between SeP and OSCE performance. The authors also compared the OSCE performances of students whose ranks changed after interviews (SeP rank < AP rank or SeP rank > AP rank). The level of significance was adjusted for the number of comparisons (Bonferroni method). RESULTS: Complete data were available for 91% of eligible students (n = 222). No class showed a significant correlation between either AP or SeP rankings and OSCE performance (p > .01). Likewise, there was no difference in OSCE performance for students whose ranks changed after the interview. CONCLUSIONS: The admission ranking and interview process at this medical school did not predict clinical performance or patients' satisfaction on this OSCE.

Evaluation methods for prevention education.

The knowledge, skills, and attitudes associated with prevention cut across clinical disciplines. Thus, they are often subsets of disciplines not otherwise present in the traditional curriculum (e.g., epidemiology or statistics) or considered the province of many disciplines (e.g., risk reduction or cancer screening). Evaluation of elements of prevention education can often become lost in the myriad other outcomes that are assessed in students, or they are intermingled with other content and skills. This article highlights the value of assessing students' competence in prevention knowledge, skills, and attitudes, provides general guidance for programs interested in evaluating their prevention instructional efforts, and gives specific examples of possible methods for evaluating prevention education. While it is important to tailor assessment methods to local institutional objectives, it is possible to share assessment methods and materials regionally and nationally. Sharing problems, as well as successes, encountered in developing appropriate assessment methods will advance the field of evaluation of prevention curricula.

Responding to patients' emotions: important for standardized patient satisfaction.

BACKGROUND AND OBJECTIVES: Several experts have emphasized the need to respond to a patient's emotions as an essential component of effective medical interviewing. This study examined the relationship of faculty observers' scores of students' performance in standardized patient (SP) interviewing stations in a family medicine clerkship objective structured clinical examination (OSCE) with SP satisfaction measures. METHODS: The faculty observers scored students in the following performance domains: 1) interviewing skills, 2) negotiating the diagnosis or plan, 3) gathering case-specific content information, 4) responding to the patient's emotions, and 5) student's overall performance. Pearson Product-Moment correlations were calculated for each of these domains and the Standardized Patient Satisfaction Questionnaire (SPSQ) scores. RESULTS: There were moderate correlations between the SPSQ score and the overall OSCE score (.45) and the response to patient's emotions skill score (.36). The faculty observer's response to patient's emotion score correlated highly with the student's overall OSCE score (.75). CONCLUSIONS: A student's ability to respond to the patient's emotions appears to be an important skill for successful medical interviewing from both the faculty observer's perspective and the SP's perspective. Results also demonstrate that the SP's perspective is similar, but not identical, to the faculty observer's perspective, suggesting that SPs have an important evaluative role in student assessment.

Recruitment behavior and program directors: how ethical are their perspectives about the match process?

OBJECTIVE: This study examined family practice residency directors' perspectives on the 1999 National Resident Matching Program (NRMP) process and identified directors' expectations for students' recruitment behavior. METHODS: Subjects were the family practice residency program directors. A 22-item written questionnaire was mailed to each director. The questions related to the directors' perceptions of the following issues: applicants interviewing in more than one specialty, communication initiated by programs or applicants, commitments made to applicants and by applicants, ethical dilemmas faced by the program director, and the NRMP process itself. Descriptive statistics were reported. RESULTS: Only a few of the residency program directors (9.1%) felt that it was ethically wrong for an applicant to interview in more than one specialty. However, most program directors (83%) indicated that the knowledge of an applicant interviewing in more than one specialty had a "significant" negative or "some" negative effect on the applicant's rank order. Ninety-five percent of program directors indicated that they engage in follow-up communication with applicants following the formal interview. Almost all program directors (98%) reported that at least some applicants contact them following the formal interview to inform them that the program was a "high" or No. 1 rank-order choice. The majority of program directors (94%) felt that the NRMP process placed their program in the position of having to be dishonest with applicants to match their top choices. CONCLUSIONS: The results of the study indicate that the actions of many program directors and applicants may not be consistent with the written policies of the NRMP.

A multidimensional approach to breast cancer education.

BACKGROUND: This study was undertaken to present a multidimensional breast cancer education package (BCEP) to medical students in an effort to improve breast cancer education. METHODS: The students were exposed to a four-part BCEP consisting of a hands-on structured clinical instruction module (SCIM), a lecture, a problem-based learning (PBL) small-group discussion, and a written manual. Each component was evaluated with a questionnaire. Students responded to the items using a five-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). RESULTS: The mean overall evaluations for the BCEP components were: SCIM, 4.6; lecture, 4.0; manual 3.8, and PBL discussion, 3.6. Highly rated qualities of the SCIM included organization (4.7), faculty preparedness (4.8), and opportunity to practice skills (4.5). The students agreed that the lecture (4.1), manual (3.8), and PBL discussion (4.2) had prepared them for the SCIM. CONCLUSION: This innovative BCEP effectively improved students' understanding of breast cancer.

Curricular renewal for the new millennium at the Medical University of South Carolina College of Medicine.

The MUSC College of Medicine is engaged in a curricular renewal process that emphasizes increased integration of the basic and clinical sciences throughout all four years of the curriculum, more self-directed learning, and earlier patient contact for students. Several basic science courses have been modified and a new "Doctoring Curriculum" has been introduced to develop students' clinical skills and preparation for medical practice. Changes to the third year of the curriculum include the new Deans' Rural Primary Care Clerkship. Other third-year curricular changes include small-group case discussion sessions that emphasize the integration of basic and clinical sciences in medical practice, and the incorporation of nutrition throughout all fours of the curriculum. The changes described in this manuscript are designed to address a wide range of educational needs of future physicians, including the acquisition of the attributes endorsed by the AAMC MSOP--altruism, knowledge, skillfulness and dutifulness. This new curriculum will evolve over time and the goal remains to help equip future physicians with the requisite knowledge, skills and attitudes for medical practice in the new millennium.

Students' attitudes towards computer testing in a basic science course.

OBJECTIVES: The introduction of computerized testing offers several advantages for test administration, however, little research has examined students' attitudes toward computerized testing. This paper, reports the attitudes of 202 students in a first year cell biology and histology course toward computerized testing and its influence on their study habits over a three year period. DESIGN AND METHODS: Multiple choice and image-based extra credit examinations and summative image-based examinations have been successfully administered in the course. The results indicate that students readily accept computer exams and that their study habits were influenced in a positive manner by the computer administered extra-credit examinations. RESULTS: Our results provide further evidence that medical students like the use of computer administered examinations and that the examinations may actually accentuate the learning experience.

Cancer survivors as standardized patients: an innovative program integrating cancer survivors into structured clinical teaching.

BACKGROUND: Increasingly, standardized patients are involved in medical education; however, reports of cancer survivors functioning as standardized patients have not been available. This study describes the participation of cancer survivors as standardized patients in structured clinical teaching. METHODS: Forty-two cancer survivors, 354 trainees, and 54 faculty members took part in the structured clinical instruction modules (SCIMs) at five academic institutions. After completing the SCIMs, the cancer survivors answered evaluation questionnaire items concerning their perceptions of the course, and all participants (cancer survivors, faculty members, medical students, and residents) rated the benefit of the participation of cancer survivors. The evaluation items were rated on a five-point scale ranging from 1 = "strongly disagree" to 5 = "strongly agree. RESULTS: The evaluation responses were very positive, and the cancer survivors expressed a strong willingness to participate in future courses. Faculty members, residents, and medical students all rated the benefit of using cancer survivors highly. CONCLUSIONS: The participation of cancer survivors in structured clinical teaching was considered beneficial not only by the cancer survivors themselves, but also by the faculty members, residents, and medical students who were involved in the educational program. The role of cancer survivors in the education of physicians needs to be expanded.

Is match ethics an oxymoron?

BACKGROUND: Graduate medical education has undergone economic and structural changes-changes that have placed increasing pressure on medical students and programs to match effectively. This study documents the experiences, perceptions, and ethical dilemmas of medical students with the 1998 match process. METHODS: Surveyed were 437 senior students from three medical schools. Students were questioned about: interviewing practices, communication with programs, commitments made, ethical dilemmas faced, and the match process itself. Data were analyzed using Student's t test, the chi-square test, and descriptive statistics. RESULTS: In all, 314 (72%) students responded. Programs expect postinterview communication from students (57%). Students perceive that programs are making "informal" commitments (43%), lying to them (33%), and encouraging their unethical behavior in order to match (21%). Ethical dilemmas are related to requests for informal commitments. CONCLUSIONS: The NRMP's ruling that denounces prematch commitments is being broken by students and programs alike, resulting in the promotion of unprofessional behavior and gamesmanship.

Xenon-131 surface sensitive imaging of aerogels in liquid xenon near the critical point.

In recent years, optically pumped xenon-129 has received a great deal of attention as a contrast agent in gas-phase imaging. This report is about the other NMR active xenon isotope (i.e., xenon-131, S = 32) which exhibits distinctive features for imaging applications in material sciences that are not obtainable from xenon-129 (S = (1/2)). The spin dynamics of xenon-131 in gas and liquid phases is largely determined by quadrupolar interactions which depend strongly on the surface of the surrounding materials. This leads to a surface dependent dispersion of relaxation rates, which can be substantial for this isotope. The dephasing of the coherence due to quadrupolar interactions may be used to yield surface specific contrast for imaging. Although optical pumping is not practical for this isotope because of its fast quadrupolar relaxation, a high spin density of liquid xenon close to the critical point (289 K) overcomes the sensitivity problems of xenon-131. We report the first xenon-131 magnetic resonance images and have tested this technique on various meso-porous aerogels as host structures. Aerogels of different densities and changing levels of hydration can clearly be distinguished from the images obtained.