Biomedical subjects

C N Henderson

Publications and source records attributed to C N Henderson.

5 recordsLinked to original sources

PubMed1999

Developing a clinical competency examination in radiology: part I--test structure.

BACKGROUND: There is a need for radiology educational outcome measures that evaluate clinical competency. This is the first of two articles introducing a clinical competency examination in radiology. This first article describes the evolution and structure of the examination. The second article presents the results of two administrations of the examination and evaluates possible outcome predictors. OBJECTIVE: To develop a measure of clinical competency in radiology. DESIGN: Descriptive. METHODS: A test was developed to simulate the radiologic interpretive skills needed in clinical chiropractic practice. Students were timed as they responded to questions regarding the localization, categorization, management, and identification of pathologic conditions presented on plain film images of the spine and chest. Twenty-five radiographic cases were displayed at individual viewbox stations, and student responses to the 4 questions were compared with the consensus responses of 2 radiology instructors. RESULTS: Two versions of the test, using different cases, were given to the same ninth trimester class of 210 chiropractic students in a 10-trimester program. Of the 210 students, 116 (55.2%; 86 men and 30 women) took version 1 of the examination, and 1 month later 181 (86.2%: 138 men and 43 women) took version 2 of the examination. Student comments after each examination were favorable. CONCLUSION: The test structure uniquely provides information related to the student's ability to localize, categorize, manage, and identify pathologic conditions on imaging studies. At present the examination is instructor time intensive; further refinement is needed before wide implementation can occur.

Chiropractic↗

PubMed1999

Developing a clinical competency examination in radiology: part II--test results.

BACKGROUND: This is the second of two articles introducing a clinical competency examination in radiology. The first article described the structure, administration, and postexamination student comments for two versions of the radiology competency examination. This article reports the results obtained from these two administrations of the examinations. OBJECTIVE: To measure and identify potential outcome predictors of student aptitude in clinical film interpretation. DESIGN: Experimental. METHODS: An examination was developed to simulate the radiologic interpretive skills needed in clinical chiropractic practice. Two versions of the examination were given to a class of 210 ninth trimester students in a 10-trimester chiropractic program. Linear regression and bivariate correlations were performed on possible predictors of student success and test scores on the version 2 examination. RESULTS: On version 1 of the examination, students were able to identify an average of 59.6% of the normal cases as normal and 51.6% of abnormal cases as abnormal. On version 2, 55.6% of the normal cases were recognized as normal and 58.2% of abnormal cases as abnormal. On both versions, students were less successful at correctly categorizing, managing, or naming pathologic conditions they found. Of the predictors evaluated, only the students' grades in the third radiology course (tumors, arthritides, and extremity trauma) and the scores on the diagnostic imaging section of National Boards part II were significant predictors. DISCUSSION: Our results should cause some concern for educators who use content-based radiology curricula. Students demonstrated poor abilities to recognize, categorize, manage, and identify common radiographic pathologic conditions. Educators cannot rely on National Board scores and course grades to determine student clinical competency. More radiology clinical competency exercises that emphasize film interpretation need to be incorporated into content-based curricula.

Aptitude↗

PubMed1996

A cross-sectional study correlating cervical radiographic degenerative findings to pain and disability.

STUDY DESIGN: A cross-sectional design was used to correlate cervical radiographic findings of spinal degeneration to neck pain and disability. OBJECTIVES: The results were correlated to assess the clinical importance of radiographic spinal degeneration. SUMMARY OF BACKGROUND DATA: Past investigations suggest little association between clinical findings and radiographic evidence of spinal degeneration. However, changes in activities of daily living and chronicity of complaint have not been investigated. METHODS: Over a 5-month period, data were collected on 700 consecutive patients referred for cervical radiographic examination as part of their clinical evaluation. While in the radiology department, all subjects completed a visual analog pain scale, neck disability index, and short questionnaire, all of which quantified various aspects of any neck complaint. Relationships between indices of patient complaint and the number of cervical degenerative intervertebral discs were evluated using regression analysis. RESULTS: A significant relationship (P < 0.001) was noted between the number of levels of intervertebral disc degeneration and the chronicity of cervical complaint. No significant relationship was found between cervical degeneration and past trauma (P = 0.904) or gender (P = 0.213). Multiple-regression analysis of visual analog pain scale scores revealed a significant two-way interaction with chronicity and past trauma (P = 0.007) and a significant main effect with gender (P < 0.001). Cervical degeneration was not significant as a main effect or interaction with other factors. Multiple-regression analysis of neck disability index scores demonstrated a significant three-way interaction of chronicity, degeneration, and gender (P = 0.022) and a significant two-way interaction for chronicity and trauma (P = 0.025). No additional information was gathered by multivariate multiple-regression techniques. CONCLUSIONS: Increasing levels of spinal degeneration are related to increasing chronicity of patient complaints. Spinal degeneration is not related to past trauma or gender. Women, but not men, report higher disability with increasing levels of degeneration. Subjects with past trauma reported more intense pain and disability. Overall, men reported less neck pain and disability than women.

Activities of Daily Living↗

PubMed1996

Articular cartilage surface changes following immobilization of the rat knee joint. A semiquantitative scanning electron-microscopic study.

Normal articular cartilage surfaces are not flat and smooth, but are contoured with various degrees of roughness. We applied the articular surface classification system developed by Jurvelin to evaluate contour and surface quality changes in rat patellae after varying periods of knee joint immobilization. In our study, one knee joint was immobilized in each of 20 rats, while the contralateral joint served as a free-moving control. Scanning electron-microscopic montages were constructed and the entire cartilage surface was subdivided by contour and surface quality areas. The total articular surface area and all contour and surface quality subclass areas were then calculated for both joints in each rat. Numerous studies have demonstrated that joint immobilization induces degenerative changes in articular cartilage. We found a correlation between the duration of immobilization and changes in the measured area of contour and surface quality subclasses. There was a statistically significant decrease of the even surface area in the weight-bearing, central region of the patellae. This corresponded to a statistically significant increase in the slightly uneven articular surface area usually found just peripheral to this weight-bearing region. There was also a less pronounced (but not statistically significant) decrease in the smooth surface area with a corresponding increase in the rough surface area of the patellae following immobilization. Closer examination of these surfaces revealed that the superficial cartilage layer in the central, weight-bearing areas had less ground substance than other areas. In addition, there appeared to be two different fiber diameters in the superficial cartilage layer of the rat patellae. These were predominantly collagen fibers (142.3 +/- 31.5 nm in diameter) generally running parallel to the long axis of the patella, occasionally random in orientation, and sometimes presenting on the cartilage surface as collagen tips and much more scarce fibrils (20.0 +/- 4.8 nm in diameter) randomly crossing the larger collagen fibers.

Animals↗

PubMed1991

Enhancement of horseradish peroxidase histochemistry and/or uptake with radiocontrast media.

The effects of dissolving horseradish peroxidase (HRP) or HRP conjugated to wheatgerm agglutinin (WGA-HRP) in radiocontrast media (MD76) on the intraaxonal transport and enzymatic activity of these tracers were evaluated both in vivo and in vitro. The in vivo studies showed that more reaction product was visible in the L4 dorsal horn following soaking of the sciatic or peroneal nerve, or following cutaneous injection of WGA-HRP, when WGA-HRP was dissolved in MD76, as compared to dissolving WGA-HRP in distilled water. Additionally, there appeared to be an enhancement of anterograde transport and a reduction of retrograde transport of WGA-HRP when this tracer was dissolved in MD76, as compared to dissolving it in distilled water. The in vitro studies indicated that radiocontrast media increased the enzymatic activity of both WGA-HRP and HRP as compared to their enzymatic activity in distilled water when assayed spectrophotometrically. Data are presented that indicate some binding (about 4%) of HRP with MD76. This binding of HRP with organically bound iodine may account for the enhancement of anterograde transport and/or increased enzymatic activity.

Animals↗