Biomedical subjects

T R TenHave

Publications and source records attributed to T R TenHave.

34 records · Page 2Linked to original sources

PubMed1994

Interactive method of informing patients of the risks of intravenous contrast media.

PURPOSE: To evaluate interactive computer-based informed consent for use of contrast material versus the same information in a written format. MATERIALS AND METHODS: Patients (n = 160) referred for radiologic examination with intravenous contrast material were block randomized (sex, age, and previous exposure to contrast material) into two groups and were provided either written or computer-based (video) informed consent. RESULTS: The female patients in the video group scored better on the test than those in the group with the written consent form. Male patients attained equivalent scores with both types of consent. The video took an average of 1.6 minutes longer to complete, probably because the majority of patients chose to be informed of every risk of intravenous contrast material. CONCLUSION: This project demonstrates that a video format for informed consent before use of intravenous contrast material offers a good alternative to the written consent form.

Comprehension↗

PubMed1994

The effect of informed consent on the level of anxiety in patients given i.v. contrast material.

OBJECTIVE: A common reason given for not obtaining informed consent before the use of IV contrast material is that the anxiety created by informing patients of potential reactions will increase the possibility of their occurring. However, the idea that this is possible is debatable, and no study of this subject has used a standardized anxiety index. Accordingly, using the State-Trait Anxiety Inventory, we assessed the anxiety level among patients about to have an IV contrast procedure and measured the effect of informing them of the risks associated with the use of contrast material. SUBJECTS AND METHODS: Approximately 2050 adult outpatients at three separate medical centers were solicited for participation in this study. Each of the 1251 patients who volunteered to participate was placed into one of six groups. The majority were patients who were awaiting the injection of either ionic or nonionic contrast material and who were or were not informed of the risks associated with the use of IV contrast material. The last two groups were generally healthy outpatients reporting for routine X-rays who were not awaiting IV contrast administration but who were informed of the risks associated with the use of ionic and nonionic contrast material. Each patient informed of the risks was asked to read a standardized consent form, and all patients completed a standardized anxiety index. RESULTS: Patients who were informed of the risks associated with IV contrast material did not have measurably increased anxiety, and they did not have an increased prevalence of adverse reactions. Indeed, the only patients who had statistically significant increased anxiety compared with the other groups were among those awaiting the injection of ionic contrast material who were not informed of the risks (p = .04). The majority (51-78%) of patients in all six groups had measurable elevated anxiety scores. CONCLUSION: We conclude that it is not justified to fail to obtain informed consent in order to avoid anxiety-induced adverse reactions to IV contrast material. The majority of patients awaiting injection of IV contrast material have measurable increased anxiety levels regardless of whether they are informed of its risks.

Anxiety↗

PubMed1989

Skeletal changes associated with extraoral appliance therapy: an evaluation of 200 consecutively treated cases.

Questions exist concerning the degree to which orthodontic treatment alters facial form. This study has attempted to discern changes in several measures of vertical facial form which might be influenced by varying vectors and amounts of extraoral force. The data were collected from pre- and posttreatment lateral cephalograms of 200 children treated consecutively with full edgewise orthodontic appliances. The sample was divided into three pretreatment groups based on the type of extraoral force delivered; cervical, "combi," and no-headgear. All groups showed a wide range of variation in treatment response, but did not demonstrate significant differences. While the extraoral forces predictably improved horizontal maxillo-mandibular discrepancies, there was too much variation in response to predict vertical changes.

Adolescent↗

PubMed1989

A comparison of skeletal and dental changes produced by function regulators (FR-2 and FR-3).

The lateral skull radiographs of subjects taken before and after treatment with the FR-2 (N = 99) and FR-3 (N = 30) of Fränkel were compared to contrast the effects of each appliance. The major skeletal effect of both appliances was on the mandible, the FR-2 group showing a significantly greater annual increase in total length and ramus height (P less than 0.001) and the FR-3 group a significant change in position downward and backward facilitated by an opening of the cranial base angle. The greater annual increase in lower facial height, compared with a control group, seen in both FR groups was accompanied by a reduction in overbite, which was greater in the FR-2 group. The favourable change in overjet seen in both FR groups was contributed to by alteration in upper and lower incisor inclination.

Activator Appliances↗

PubMed1988

Imprecision and bias in orthodontic treatment results.

Imprecision in treatment response has been defined as inconsistent unpredictable results from the same treatment. Bias has been defined as systematic failure to achieve defined treatment goals. Concepts of imprecision and bias are applied to the results of a study of soft-tissue response to Class II treatment with edgewise and Herbst appliances.

Clinical Protocols↗

PubMed1988

Mandibular position in class III malocclusion.

Lateral skull radiographs of 66 subjects with Class III malocclusion, characterized by lingual occlusion of the upper incisors and a degree of overbite, taken before and after treatment were compared with a Control Group of similar mean age and interval between films. Vertical, Horizontal and Oblique measurements were made to establish the part played by overclosure and anterior displacement of the mandible in the aetiology of Class III malocclusion. The results suggest that both may play a part but that the former is of more general significance than the latter.

Cephalometry↗

PubMed1987

Associations between occlusal characteristics and signs and symptoms of TMJ dysfunction in children and young adults.

Cross-sectional data were obtained from 1,342 subjects 6 to 17 years of age and analyzed for the prevalence of (1) specific types of occlusion, and (2) subjective symptoms and clinical signs of TMJ dysfunction. The results, as they pertained to occlusion and clinical signs, were as follows: functional shift was negatively associated with TMJ and muscle tenderness; open bite was positively associated with TMJ and muscle tenderness; excessive or negative overjets were more likely to have joint tenderness; older subjects with a cusp-to-cusp or a Class II molar relationship were more likely to experience TMJ and muscle tenderness, and restricted opening; and buccal crossbites had a significantly higher prevalence of joint sounds in older children. Results pertaining to occlusion and subjective symptoms were as follows: Class II molar relationship was positively associated with joint noise in the 6 to 8 and 15 to 17-year age groups; and subjects with negative overjet were more likely to report joint noise. Our conclusions were that (1) statistical associations exist between certain features of occlusion and TMJ signs/symptoms, and (2) such associations are greater in the older groups tested.

Adolescent↗

PubMedDate not supplied

Multiple fine-needle biopsies using a coaxial technique: efficacy and a comparison of three methods.

PURPOSE: Compare the success of three coaxial fine-needle biopsy techniques in obtaining multiple cytologic specimens of high quality. METHODS: For each of three different biopsy needle and technique combinations (aspiration: 22-gauge Chiba; capillary: 22-gauge Chiba; 22-gauge Autovac aspiration biopsy gun), 30 sites (15 liver, 15 kidney) were selected for coaxial fine-needle biopsy in cadaveric liver and kidneys. For each coaxial technique, three sequential biopsies were performed through an 18-gauge coaxial needle at each of multiple sites. The quality of the resultant 270 specimens was graded by a blinded cytopathologist using a previously published grading scheme. RESULTS: Using the coaxial technique, there was no significant dropoff in the cytologic specimen quality among the first, second, and third biopsies at a specific site, regardless of the order of the techniques/needles used. This was true for organs, the overall data, and for the individual five grading criteria. There was, however, a significant difference among the biopsy techniques themselves. Though there was no difference in the quality of cytopathologic specimen obtained with the Autovac aspiration gun and the aspiration technique with a 22-gauge Chiba needle, both were statistically better than the nonaspiration, capillary technique utilizing a 22-gauge needle (p = 0.0001). CONCLUSION: The use of a coaxial technique with a fine-needle, 22-gauge biopsy offers unique advantages in obtaining a nearly unlimited amount of high-quality material for cytopathologic analysis. In this study, no dropoff was found in specimen quality with subsequent biopsies.

Biopsy, Needle↗

PubMedDate not supplied

Capillary versus aspiration biopsy: effect of needle size and length on the cytopathological specimen quality.

PURPOSE: To test the value of the nonaspiration, or capillary, biopsy technique by experimental comparison with the conventional fine-needle aspiration technique using various needle gauges and lengths. METHODS: On fresh hepatic and renal tissue from five autopsies, multiple biopsy specimens were taken with 20, 22, and 23-gauge Chiba needles of 5, 10, 15, and 20-cm length, using the aspiration technique and the capillary technique. The resultant specimens were graded on the basis of a grading scheme by a cytopathologist who was blinded to the biopsy technique. RESULTS: The capillary technique obtained less background blood or clot which could obscure diagnostic tissue, although not significantly different from the aspiration technique (p = 0.2). However, for the amount of cellular material obtained, retention of appropriate architecture, and mean score, the capillary technique performed statistically worse than aspiration biopsy (p < 0.01). In addition, with decreasing needle caliber (increasing needle gauge) and increasing length, the capillary biopsy was inferior to the aspiration biopsy. CONCLUSION: The capillary biopsy technique is inferior to the aspiration technique according to our study. When the capillary technique is to be applied, preference should be given to larger caliber, shorter needles.

Biopsy, Needle↗

PubMedDate not supplied

Development of a model angiography informed consent form based on a multiinstitutional survey of current forms.

PURPOSE: To develop an informative consent form for angiography that can be read and understood by a patient with an eighth-grade level of education. MATERIALS AND METHODS: Consent forms from 125 medical centers were evaluated with RightWriter 4.0 software. The readability index, a measure of educational grade level needed to understand a document, was determined for each form. Features of forms and discussion of complications were evaluated. A model consent form was developed. RESULTS: Analysis of 27 consent forms revealed a mean readability index of 14.2; to adequately understand the documents, an average of 2.2 years of college were required. Alternatives to the procedure were listed in 14 forms (52%). All consent forms listed potential complications, but only 15 (56%) identified specific numeric risks, and attempts to classify complications according to severity were made in only five (18%). CONCLUSION: An angiography consent form has been developed that can be understood with an eight-grade level of education. It should allow patients to more easily understand the procedure and its risks, benefits, and alternatives. It remains the obligation of the physician to tailor the discussion for each procedure to meet the needs of each patient.

Academic Medical Centers↗

PubMedDate not supplied

The quality of 3D reconstructions from 1.0 and 1.5 pitch helical and conventional CT.

PURPOSE: CT data are commonly used to create 3D images. For this purpose, thin and overlapped slices are desirable. Helical (spiral) CT offers the ability to adjust the slice reconstruction interval from 0 to 100%. However, its use in 1.0 and 1.5 pitch helical CT and 3D imaging, especially with respect to surface detail, is relatively untested. METHODS: Ten objects selected for their varying size, shape, and density were scanned (fourth generation Picker PQ2000) by contiguous 2,4 and 8 mm conventional and helical sequences. The latter were obtained with a pitch of both 1.0 and 1.5 and were reconstructed into a 3D image with 0-75% overlapping of the reconstructed slices. Each of the 24 different sequences per scanned object was reconstructed into identical sets (projections) of 3D images displayed on color film. The 24 3D image sets for each object were submitted to six blinded radiologists who separately ranked them from best to worst. RESULTS: 3D reconstructions obtained from CT scans with a thinner slice thickness, half-field (15 cm FOV), and helical technique were rated as statistically superior. The 1.0 and 1.5 helical sequences obtained with a 4 or 8 mm slice thickness scored statistically better than 3D reconstructions from equivalent conventional scans. Overlapping of the reconstructed helical slices by 25-75% generally improved the quality of the 3D reconstruction. CONCLUSION: Helical CT with either a 1.0 or a 1.5 pitch offers the ability to obtain higher quality 3D reconstructions than from comparable conventional CT scans.

Humans↗

PubMedDate not supplied

The impact of 2D versus 3D quantitation of tumor bulk determination on current methods of assessing response to treatment.

PURPOSE: Measurements from sequential axial "2D" data in cancer patients are commonly used to assess treatment response or disease progression. This study compares the volume of tumor bulk calculated with 3D reconstructions with that calculated by conventional methods to determine if it might change patient classification. METHOD: All medical, gynecologic, and pediatric oncology patients under treatment who were evaluated with serial CT scans between January 1, 1992, and July 31, 1994, for whom the digital data were available were included in this study. For each tumor site, the maximum diameter and its perpendicular were measured and multiplied together to yield an area. The sum of areas of the measured lesions was used as an approximation of overall 2D tumor volume. In addition, the 2D area of each site was multiplied by its height, yielding a 2D volume. Last, the digital data were loaded into a 3D computer system and total 3D tumor volumes determined. All medical and gynecologic oncology patients were treated based upon the 2D area of tumor. The pediatric oncology patients were treated based upon the 2D volume of tumor measured as per standard practice. The members of each treating oncologic service assessed their patients as to how the other two methods would have changed their classification of the patients' response category. RESULTS: Four hundred thirty-three CT scans were performed in 139 patients, which included 204 baseline and 294 follow-up CT examinations. Seventy patients had new tumor foci and would have been classified as failure by all three methods of tumor bulk measurement. The 3D volume versus the 2D area method of tumor bulk assessment would have changed response categories in 52 of the 294 follow-up CT examinations (p < 0.0001). Thirty-five patients were recategorized from either "no response" to "failure" (21 patients) or "no response" to "response" (14 patients) categories. If only those follow-up studies without new metastatic foci are considered, the 3D volume versus the 2D area methods of tumor assessment would have changed the treatment response category in 23.2%. The use of the 2D volume method of calculating tumor volume of bulk tended to overestimate the overall tumor size by an average of 244 cm3 (p = 0.001). CONCLUSION: The 3D method of tumor volume measurement differs significantly from conventional 2D methods of tumor volume determination. Large prospective studies analyzing the usefulness of 3D tumor volume measurements and assessing possible changes in patient response categories would be required for full utilization of this more accurate method of following disease bulk.

Adolescent↗

PubMedDate not supplied

The effect of helical CT on X-ray attenuation.

PURPOSE: Conventional CT has been shown to have wide variability in measured CT attenuation, both temporally within the same scanner and between different scanners. Many radiologists have raised the concern that the increased noise and multiple variables associated with helical CT may lead to degradation in resolution, specifically causing errors in CT number values. This study was designed to specifically evaluate the performance of both types of CT scanning in this regard. METHOD: A Picker PQ2000 helical CT scanner was used to scan a phantom containing multiple tissue-equivalent densities, allowing the measurement of CT attenuation of soft tissue, distilled water, cortical bone, medullary bone, air, and fat with a variety of techniques. A Catphan phantom was imaged with a variety of slice thicknesses (2, 4, and 8 mm), phantom positions (isocenter, y = +20 cm), and pitches (1.0, 1.5, 2.0) using both conventional and helical sequences. The entire image set was repeated with two additional annuli placed around the Catphan phantom to simulate the abdomen and the calvarium. The attenuation measurements of the same imaging parameters for helical versus conventional CT were statistically compared. RESULTS: No statistical differences were found for the CT numbers based on scan type (conventional versus helical) for all sequences and gantry positions tested, including helical CT with pitches > 1.0. Greater CT number variability was found with the extremes of tissue density such as with air and especially cortical bone, but were not statistically significant. The addition of the abdominal and calvarial annuli created a greater variation in CT attenuation values, but again were not statistically significant. CONCLUSION: The measurement of X-ray attenuation does not vary significantly with the use of the helical technique.

Adipose Tissue↗

PubMedDate not supplied

The optimization of helical thoracic CT.

PURPOSE: Our purpose was to determine the optimal helical thoracic CT scanning protocol. METHOD: Three adult Suffolk sheep under general anesthesia were repeatedly scanned by a variety of variable thickness helical and conventional plus thin section high resolution (lung gold standard) CT sequences, reconstructed for mediastinal (standard interpolator and algorithm) and lung parenchymal (extrasharp interpolator, bone algorithm) detail. The images were evaluated in a random order by five separate blinded, experienced imagers utilizing a predetermined grading scale. RESULTS: At equivalent slice thicknesses, the mediastinal images showed no statistically significant differences between conventional and helical CT using pitches of 1.0, 1.5, and 2.0. However, the 5-mm-thick sections, regardless of technique, performed better than did either the 2- or the 10-mm-thick section images. For the lung interstitium, there was an obvious and marked advantage to reconstructing the lung images separately from the mediastinal images with edge-enhancing algorithms and interpolators. With 1-mm-high mA thin section, high resolution lung CT as the gold standard, 2 mm conventional and helical pitch 1.0, 1.5, and 2.0 images were all graded equivalent. Of the 5 mm images, the helical pitches of 1.0 and 1.5 were graded equivalent to the gold standard. All of the 10 mm lung sections using both conventional and helical CT were graded statistically worse than the gold standard (p < 0.05). CONCLUSION: The use of helical CT with a 5 mm beam collimation and a pitch of 1.0 or 1.5 reconstructed twice to maximize both the mediastinal and the lung parenchymal detail provides the optimal way to routinely evaluate the chest.

Algorithms↗

PubMedDate not supplied

Cultural identity and health lifestyles among African Americans: a new direction for health intervention research?

OBJECTIVES: To assess associations of cultural and personal identity variables with socioeconomic status (SES) and health lifestyle in African Americans. DESIGN: Cross-sectional. METHODS: A questionnaire administered to 333 African Americans, ages 40-70 years, at enrollment in a nutrition education study assessed: African-American cultural identity (15 items scored 1 [low] to 4 [high]); reference group (two questions about perceived success in the Black or White way of life-scored as bi-cultural if "yes" to both); personal identity (4 items on: self-concept as attractive, self-confident, satisfied and friendly-scored 1 [no/not sure] or 2 [yes]); and selected demographic and lifestyle variables. RESULTS: Cultural identity factors reflecting participation in and belonging to African-American culture and bi-cultural reference group were related to higher SES, lower fat diets, not smoking, current drinking, and higher leisure time physical activity (cultural identity only), particularly in women (P<.001 to P = .06). Associations of cultural identity with physical activity and of bi-cultural reference group with low-fat eating and not smoking (females) remained significant at P<.05 after adjustment for SES. CONCLUSIONS: A greater emphasis is needed on aspects of cultural identity that are positively related to health lifestyles as distinct from aspects that might act as barriers.

Adult↗

PubMedDate not supplied

Clinical validity of the relationship between TMJ signs and symptoms in children and youth.

Cross-sectional data on subjective symptoms and clinical signs of TMJ dysfunction were collected from 1342 subjects ranging in age from 6 to 17 years old. Statistically significant associations existed between certain symptoms and signs (p less than .0001); however, these associations lacked correspondence as indicated by the sensitivity (from 2 percent to 40 percent) and false-positive rates (52 percent to 77 percent) of the symptom-related interview questions. These findings do not support drawing valid clinical conclusions from cross-sectional sign and symptom studies of TMJ dysfunction in children.

Adolescent↗