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PubMed2000

Patterns of use, attitudes and expectations of mental health staff regarding computers.

There is limited information on the views of mental health staff about computers. The present study aimed to ascertain the patterns of use, attitudes and expectations of staff from a comprehensive mental health service regarding computers before and after the purchase of new equipment and training. A questionnaire was sent to staff of the Central Sydney Mental Health Services working in sites targeted for new computer equipment and training. Most respondents, especially those with computer experience or who had worked in mental health for less than 5 years, viewed computers favourably. At the same time, half the respondents did not feel they had sufficient access to a computer at work and the vast majority had not received training as intended. Commitments to provide computer equipment and training must be followed through, otherwise staff may feel disenchanted and computers may be regarded less favourably. A measure of the positive views about computer use ('positivity index') developed during the course of the current study may have wider applicability.

Adult↗
PubMed2002

Validation of computer morphs for grading contact lens complications.

Abstract An alternative to the use of printed grading scales for assessing the severity of contact lens-induced ocular pathology is to use computer-generated grading morphs. This technique involves manipulation of a continuously variable movie sequence until this matches the severity of the condition being observed. To validate the use of computer morphs, nine experienced optometrists were each invited to grade - to the nearest 0.1 increment - an image of each of 16 contact lens complications, using printed scales (Efron Grading Scales for Contact Lens Complications) and computer morphs (Efron Grading Morphs). This entire procedure was repeated approximately 2 weeks later, yielding a total data base comprising of 576 individual grading estimates. Good accuracy was achieved using computer morphs, as evidenced by the similarity between the mean of the test and retest grading estimates for the printed scales (2.8 +/- 0.7) and the computer morphs (2.6 +/- 0.8) (F1,8 = 2.7, p = 0.14). There was no difference in median reliability between the printed scales (+/- 0.41) and the computer morphs (+/- 0.43) (Z = 0.1, p = 0.95). Computer morphs are thus considered to have been validated in view of their accuracy and reliability compared with printed scales. In addition, computer morphs offer considerable utility in terms of computer-based clinical record keeping, teaching and learning, and clinical research.

Computer Graphics↗
PubMedDate not supplied

The psychosocial impact of interactive computer use within a vulnerable elderly population: a report on a randomized prospective trial in a home health care setting.

Quality of care for vulnerable elderly clients makes it important to consider the psychosocial effects of interactive computer use as a means to communicate for social, functional, and/or health care purposes in a home health care setting. In a 3-month randomized prospective trial, telecommunications terminals were installed in the private residences of computer-illiterate persons, 65-years-of-age and older, providing visiting nurses the opportunity to teach computer use with three different training methods. The control group had similar weekly nurse visits, but no computer terminal use. Pre-posttests using the Rosenberg Self-Esteem Scale and the Geriatric Depression Scale compared change in self-esteem and depression scores of computer-use clients with the scores of the control group clients. Interactive computer use, alone, did not significantly change scores. Compared to the control group, however, there was a significant change toward improved self-esteem and depression when interactive computer use was accompanied with weekly nurse computer training. Weekly training with a significant other, as a substitute for the nurse trainer, significantly improved self-esteem scores but not depression scores. Interactive computer use was not associated with decreased self-esteem or increased depression. Attitude changes and responses to the particular telecommunication service used in this study were mixed, suggesting future research should be based on improved telecommunication systems with access to programs that have greater practical application to the needs of elderly clients.

Aged↗
PubMed2002

An ergonomic evaluation comparing desktop, notebook, and subnotebook computers.

OBJECTIVE: To evaluate and compare the postures and movements of the cervical and upper thoracic spine, the typing performance, and workstation ergonomic factors when using a desktop, notebook, and subnotebook computers. DESIGN: Repeated-measures design. SETTING: A motion analysis laboratory with an electromagnetic tracking device. PARTICIPANTS: A convenience sample of 21 university students between ages 20 and 24 years with no history of neck or shoulder discomfort. INTERVENTION: Each subject performed a standardized typing task by using each of the 3 computers. MAIN OUTCOME MEASURES: Measurements during the typing task were taken at set intervals. RESULTS: Cervical and thoracic spines adopted a more flexed posture in using the smaller-sized computers. There were significantly greater neck movements in using desktop computers when compared with the notebook and subnotebook computers. The viewing distances adopted by the subjects decreased as the computer size decreased. Typing performance and subjective rating of difficulty in using the keyboards were also significantly different among the 3 types of computers. CONCLUSIONS: Computer users need to consider the posture of the spine and potential risk of developing musculoskeletal discomfort in choosing computers.

Adult↗
PubMed1991

The diagnostic performance of computer programs for the interpretation of electrocardiograms.

BACKGROUND: Computer programs for the interpretation of electrocardiograms (ECGs) are now widely used. However, a systematic assessment of various computer programs for the interpretation of ECGs has not been performed. METHODS: We undertook a large international study to compare the performance of nine electrocardiographic computer programs with that of eight cardiologists in interpreting ECGs in 1220 clinically validated cases of various cardiac disorders. ECGs from the following groups were included in the sample: control patients (n = 382); patients with left ventricular hypertrophy (n = 183), right ventricular hypertrophy (n = 55), or biventricular hypertrophy (n = 53); patients with anterior myocardial infarction (n = 170), inferior myocardial infarction (n = 273), or combined myocardial infarction (n = 73); and patients with combined infarction and hypertrophy (n = 31). The interpretations of the computer programs and the cardiologists were compared with the clinical diagnoses made independently of the ECGs, and the computer interpretations were compared with those of the cardiologists. RESULTS: The percentage of ECGs correctly classified by the computer programs (median, 91.3 percent) was lower than that of the cardiologists (median, 96.0 percent; P less than 0.01). The median sensitivity of the computer programs was also significantly lower than that of the cardiologists in diagnosing left ventricular hypertrophy (56.6 percent vs. 63.9 percent, P less than 0.02), right ventricular hypertrophy (31.8 percent vs. 46.6 percent, P less than 0.01), anterior myocardial infarction (77.1 percent vs. 84.9 percent, P less than 0.001), and inferior myocardial infarction (58.8 percent vs. 71.7 percent, P less than 0.0001). The median total accuracy level (the percentage of correct classifications) was 6.6 percent lower for the computer programs (69.7 percent) than for the cardiologists (76.3 percent; P less than 0.001). However, the performance of the best programs nearly matched that of the most accurate cardiologists. CONCLUSIONS: Our study shows that some but not all computer programs for the interpretation of ECGs perform almost as well as cardiologists in identifying seven major cardiac disorders.

Cardiology↗
PubMed2000

The effects of a computer skill training programme adopting social comparison and self-efficacy enhancement strategies on self-concept and skill outcome in trainees with physical disabilities.

PURPOSE: The aim of this controlled, quasi-experimental study was to evaluate the effects of both self-efficacy enhancement and social comparison training strategy on computer skills learning and self-concept outcome of trainees with physical disabilities. METHOD: The self-efficacy enhancement group comprised 16 trainees, the tutorial training group comprised 15 trainees, and there were 25 subjects in the control group. Both the self-efficacy enhancement group and the tutorial training group received a 15 week computer skills training course, including generic Chinese computer operation, Chinese word processing and Chinese desktop publishing skills. The self-efficacy enhancement group received training with tutorial instructions that incorporated self-efficacy enhancement strategies and experienced self-enhancing social comparisons. The tutorial training group received behavioural learning-based tutorials only, and the control group did not receive any training. The following measurements were employed to evaluate the outcomes: the Self-Concept Questionnaire for the Physically Disabled Hong Kong Chinese (SCQPD), the computer self-efficacy rating scale and the computer performance rating scale. RESULTS: The self-efficacy enhancement group showed significantly better computer skills learning outcome, total self-concept, and social self-concept than the tutorial training group. The self-efficacy enhancement group did not show significant changes in their computer self-efficacy: however, the tutorial training group showed a significant lowering of their computer self-efficacy. CONCLUSIONS: The training strategy that incorporated self-efficacy enhancement and positive social comparison experiences maintained the computer self-efficacy of trainees with physical disabilities. This strategy was more effective in improving the learning outcome (p = 0.01) and self-concept (p = 0.05) of the trainees than the conventional tutorial-based training strategy.

Adult↗
PubMed2004

Changes in breast cancer detection and mammography recall rates after the introduction of a computer-aided detection system.

BACKGROUND: Computer-aided mammography is rapidly gaining clinical acceptance, but few data demonstrate its actual benefit in the clinical environment. We assessed changes in mammography recall and cancer detection rates after the introduction of a computer-aided detection system into a clinical radiology practice in an academic setting. METHODS: We used verified practice- and outcome-related databases to compute recall rates and cancer detection rates for 24 Mammography Quality Standards Act-certified academic radiologists in our practice who interpreted 115,571 screening mammograms with (n = 59,139) or without (n = 56,432) the use of a computer-aided detection system. All statistical tests were two-sided. RESULTS: For the entire group of 24 radiologists, recall rates were similar for mammograms interpreted without and with computer-aided detection (11.39% versus 11.40%; percent difference = 0.09, 95% confidence interval [CI] = -11 to 11; P =.96) as were the breast cancer detection rates for mammograms interpreted without and with computer-aided detection (3.49% versus 3.55% per 1000 screening examinations; percent difference = 1.7, 95% CI = -11 to 19; P =.68). For the seven high-volume radiologists (i.e., those who interpreted more than 8000 screening mammograms each over a 3-year period), the recall rates were similar for mammograms interpreted without and with computer-aided detection (11.62% versus 11.05%; percent difference = -4.9, 95% CI = -21 to 4; P =.16), as were the breast cancer detection rates for mammograms interpreted without and with computer-aided detection (3.61% versus 3.49% per 1000 screening examinations; percent difference = -3.2, 95% CI = -15 to 9; P =.54). CONCLUSION: The introduction of computer-aided detection into this practice was not associated with statistically significant changes in recall and breast cancer detection rates, both for the entire group of radiologists and for the subset of radiologists who interpreted high volumes of mammograms.

Breast Neoplasms↗
PubMed2002

A prospective, randomized controlled study of computer-assisted learning in parasitology.

PURPOSE: To compare, using a prospective, randomized controlled study, three methods of teaching a medical school parasitology course: computer-based instruction, traditional lecture-based instruction, and a combination of computer-based and lecture-based instruction. METHOD: A single class of the University of Utah School of Medicine was randomized into three study groups for the second-year parasitology course. The computer group (n = 29) used a locally developed interactive parasitology computer program; the lecture group (n = 32) had traditional lectures, and the combined group (n = 33) used both the computer program and lectures. Students' knowledge was assessed using a pretest, a final examination, and a posttest administered four months after the course. Students also used logs to track the amounts of time they spent studying. Their impressions and course evaluations were collected using a standardized course-evaluation form. RESULTS: The groups' scores on the pretest, final examination, and posttest were not statistically significantly different. Students in the computer group averaged 26.8 hours of studying over the two-week course compared with 32.1 hours in the lecture group and 32.7 hours in the combined group. The difference in study times between the computer and combined groups yielded a significant p value of 0.036. Students were generally positive about the course and the computer program. CONCLUSION: Students can learn parasitology from computer-based instruction as effectively as from traditional lecture-based instruction, and they can do so in less time.

Adult↗
PubMed1991

Validation of ultrafast computed tomographic left ventricular volume measurement.

Left ventricular volume has been measured with ultrafast computed tomography. However, the accuracy with which this can be done is unknown. We therefore imaged with ultrafast computed tomography 11 rectangular phantoms, 20 to 225 ml, and 17 left ventricular casts, 15 to 112 ml. Two observers planimetered serial tomographic images and computed volume from sequential tomograms. There was no significant inter- or intraobserver difference in measurement of phantoms. Deviation of ultrafast computed tomographic volume from true phantom volume was -0.1 +/- 3.5% SD, range 9.0 to -7.6%. Correlation of true phantom volume with ultrafast computed tomographic volume was 0.99, SEE = 1.9 ml. No significant difference was observed between merged and single ultrafast computed tomographic scanning sequences. Left ventricular cast volume determined by ultrafast computed tomography deviated from true volume by 6% +/- 20%, range 54% to -45%. Correlation of true volume with ultrafast computed tomographic volume was 0.99, SEE = 5.1 ml. There was no interobserver significant difference in measurement of left ventricular cast volume. Correlation between ultrafast computed tomographic volume and cineradiographic volume of the same left ventricular casts was 0.99, SEE = 4.4 ml. Thus, phantom volumes can be measured accurately without significant intra- or interobserver variation. Merged scanning sequences did not influence volume determination. Left ventricular cast volume determination was comparable to that obtained with cineradiography.

Cardiac Volume↗
PubMed2001

A comparative trial of paper-and-pencil versus computer administration of the Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire.

BACKGROUND: Although most health-related quality of life questionnaires are self-administered by means of paper and pencil, new technologies for automated computer administration are becoming more readily available. Novel methods of instrument administration must be assessed for score equivalence in addition to consistency in reliability and validity. OBJECTIVES: The present study compared the psychometric characteristics (score equivalence and structure, internal consistency, and reproducibility reliability and construct validity) of the Quality of Life in Reflux And Dyspepsia (QOLRAD) questionnaire when self-administered by means of paper and pencil versus touch-screen computer. The influence of age, education, and prior experience with computers on score equivalence was also examined. RESEARCH DESIGN: This crossover trial randomized 134 patients with gastroesophageal reflux disease to 1 of 2 groups: paper-and-pencil questionnaire administration followed by computer administration or computer administration followed by use of paper and pencil. To minimize learning effects and respondent fatigue, administrations were scheduled 3 days apart. A random sample of 32 patients participated in a 1-week reproducibility evaluation of the computer-administered QOLRAD. RESULTS: QOLRAD scores were equivalent across the 2 methods of administration regardless of subject age, education, and prior computer use. Internal consistency levels were very high (alpha = 0.93-0.99). Interscale correlations were strong and generally consistent across methods (r = 0.7-0.87). Correlations between the QOLRAD and Short Form 36 (SF-36) were high, with no significant differences by method. Test-retest reliability of the computer-administered QOLRAD was also very high (ICC = 0.93-0.96). CONCLUSIONS: Results of the present study suggest that the QOLRAD is reliable and valid when self-administered by means of computer touch-screen or paper and pencil.

Age Factors↗
PubMed1998

A comparison of magnetic resonance and computed tomographic image quality after the implantation of tantalum and titanium spinal instrumentation.

STUDY DESIGN: Tantalum- and titanium-based lumbar interbody fusion devices were implanted into two fresh human cadavers, and magnetic resonance and computed tomographic imaging were performed to evaluate adjacent spinal structures and the amount of metallic artifact. OBJECTIVE: The objective of this study was to prospectively compare the preliminary results of magnetic resonance imaging and computed tomography scanning image quality after the implantation of both titanium and tantalum spinal implants. SUMMARY OF BACKGROUND DATA: The availability of tantalum and titanium spinal implants brings theoretical magnetic resonance imaging compatibility along with several other desirable characteristics. The magnetic resonance imaging and computed tomographic imaging of tantalum spinal instrumentation has never been studied previously or compared with titanium instrumentation. METHODS: Titanium and tantalum spinal implants produced for anterior spinal fusion were each placed at two levels in the lumbar spine of two fresh cadaver specimens. Sequential spin echo T1-weighted and T2-weighted magnetic resonance imaging studies and computed tomographic scans were obtained. The resulting images were then graded to describe and compare the behavior of tantalum metal in magnetic resonance imaging and computed tomographic studies. RESULTS: Good T1 and T2 images were obtained that allowed visualization of the neural structures with minimal artifact. The optimal T1 images for tantalum metal were similar in quality to the optimal T1 parameters for titanium metal. T2 images for both tantalum and titanium metal were obtained with similar results for both metals. Gradient echo magnetic resonance imaging scans of both were poorly imaged with a large amount of artifact. Computed tomographic studies of tantalum implants produced a large amount of metal artifact when compared with computed tomographic studies of titanium implants. CONCLUSIONS: High-quality magnetic resonance imaging studies can be obtained after the implantation of both titanium and tantalum spinal instrumentation. Both of the metals produce similar images on magnetic resonance imaging studies with comparable amounts of metallic artifact. High-quality computed tomographic scans of titanium implants can be obtained with minimal distortion secondary to artifact. However, computed tomographic scanning is not the imaging modality of choice for the tantalum spinal implants because of the large amounts of artifact.

Artifacts↗
PubMed2002

Utility of three-dimensional and multiplanar reformatted computed tomography for evaluation of pediatric congenital spine abnormalities.

STUDY DESIGN: A retrospective radiographic review of 31 patients with congenital spine abnormalities who underwent conventional radiography and advanced imaging studies was conducted. OBJECTIVE: To analyze the utility of three-dimensional computed tomography with multiplanar reformatted images for congenital spine anomalies, as compared with plain radiographs and axial two-dimensional computed tomography imaging. SUMMARY OF BACKGROUND DATA: Conventional radiographic imaging for congenital spine disorders often are difficult to interpret because of the patient's small size, the complexity of the disorder, a deformity not in the plane of the radiographs, superimposed structures, and difficulty in forming a mental three-dimensional image. Multiplanar reformatted and three-dimensional computed tomographic imaging offers many potential advantages for defining congenital spine anomalies including visualization of the deformity in any plane, from any angle, with the overlying structures subtracted. METHODS: The imaging studies of patients who had undergone a three-dimensional computed tomography for congenital deformities of the spine between 1992 and 1998 were reviewed (31 cases). All plain radiographs and axial two-dimensional computed tomography images performed before the three-dimensional computed tomography were reviewed and the findings documented. This was repeated for the three-dimensional reconstructions and, when available, the multiplanar reformatted images (15 cases). In each case, the utility of the advanced imaging was graded as one of the following: Grade A (substantial new information obtained), Grade B (confirmatory with improved visualization and understanding of the deformity), and Grade C (no added useful information obtained). RESULTS: In 17 of 31 cases, the multiplanar reformatted and three-dimensional images allowed identification of unrecognized malformations. In nine additional cases, the advanced imaging was helpful in better visualizing and understanding previously identified deformities. In five cases, no new information was gained. The standard and curved multiplanar reformatted images were best for defining the occiput-C1-C2 anatomy and the extent of segmentation defects. The curved multiplanar reformatted images were especially helpful in keeping the spine from "coming in" and "going out" of the plane of the image when there was significant spine deformity in the sagittal or coronal plane. The three-dimensional reconstructions proved valuable in defining failures of formation. CONCLUSIONS: Advanced computed tomography imaging (three-dimensional computed tomography and curved/standard multiplanar reformatted images) allows better definition of congenital spine anomalies. More than 50% of the cases showed additional abnormalities not appreciated on plain radiographs or axial two-dimensional computed tomography images. Curved multiplanar reformatted images allowed imaging in the coronal and sagittal planes of the entire deformity.

Adolescent↗
PubMedDate not supplied

Audio computerized self-report interview use in prenatal clinics: audio computer-assisted self interview with touch screen to detect alcohol consumption in pregnant women: application of a new technology to an old problem.

Computer interviewing to obtain sensitive information is not a new concept. However, concerns about the acceptance of computers in disadvantaged populations with potentially low literacy led us to combine audio- and touch-screen technologies with an audio computerized self-report interview to obtain information about alcohol use. This study evaluated acceptance and ease of use by a disadvantaged population of pregnant women in the District of Columbia. Patients attending an initial visit at prenatal clinics answered questions anonymously about their consumption of alcoholic beverages and other personal information. The questionnaire was programmed on a laptop computer. The computer administered the recorded questions via earphones, as well as displayed them on the screen, and patients answered by touching the computer screen. Results were immediately available. A total of 507 women were interviewed, who were primarily African American, non-Hispanic, and never married. Nearly 24% did not complete a high school education, 43% were unemployed, and 30% received public assistance. Most of the women (59%) used computers occasionally (a few days a month) or never. Nearly all patients (96%) reported that the computer was not difficult to use, and approximately 90% liked answering the questions by computer. The study demonstrates that using computers to screen for alcohol use in disadvantaged pregnant populations is feasible and acceptable to the patients.

Adolescent↗
PubMed2004

Accuracy of computed tomography in assessing thoracic pedicle screw malposition.

OBJECTIVE: Transpedicular instrumentation of the thoracic spine is potentially dangerous because of the close proximity of vital structures and the morphologic variability seen. Computed tomography has become the gold standard in evaluating the position of thoracic pedicle screws in vivo. Unfortunately, despite its common use, the accuracy of computed tomography has not been adequately investigated. The objective of this work was to evaluate the accuracy of computed tomography in evaluating the position of thoracic pedicle screws. METHODS: One hundred ninety-four thoracic pedicles in nine cadaveric specimens were instrumented and evaluated postoperatively with computed tomography and open dissection. Computed tomography films were assessed by three blinded observers who noted the position of each pedicle screw on two separate occasions. These data were subsequently compared with the open dissection data. RESULTS: Computed tomography was found to be 76 +/- 16% sensitive and 75 +/- 13% specific when compared with open dissection. Overall accuracy was 76 +/- 8%. Intraobserver accuracy was 79 +/- 5% in assessing thoracic pedicle screws by computed tomography. Fair to moderate degree of agreement was demonstrated for both interobserver and intraobserver data using kappa values. CONCLUSIONS: Computed tomography was found to be relatively insensitive in assessing thoracic pedicle screw position. In the face of postoperative complications, surgical exploration and hardware removal may still be necessary despite negative computed tomography.

Bone Screws↗
PubMed2005

Low spatial resolution computed tomography underestimates lung overinflation resulting from positive pressure ventilation.

OBJECTIVE: In acute lung injury, lung overinflation resulting from mechanical ventilation with positive end-expiratory pressure (PEEP) can be assessed using lung computed tomography. The goal of this study was to compare lung overinflation measured on low and high spatial resolution computed tomography sections. DESIGN: Lung overinflation was measured on thick (10-mm) and thin (1.5-mm) computed tomography sections obtained at zero end-expiratory pressure (ZEEP) and PEEP 10 cm H2O using a software including a color-coding system. SETTING: A 20-bed surgical intensive care unit of a university hospital. PATIENTS: Thirty mechanically ventilated patients with acute lung injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Overinflated lung volume was measured as the end-expiratory volume of lung regions with computed tomography attenuations <-900 Hounsfield units. Lung overinflation, expressed in percentage of the total lung volume, was significantly underestimated by thick computed tomography sections compared with thin computed tomography sections (0.4 +/- 1.6% vs. 3.0 +/- 4.0% in ZEEP and 1.9 +/- 4% vs. 6.8 +/- 7.3% in PEEP, p < .01). In patients with a diffuse loss of aeration, the overinflated lung volumes of thick and thin computed tomography sections were, respectively, 0.6 +/- 0.8 mL vs. 16 +/- 10 mL in ZEEP (p < .01) and 8 +/- 9 mL vs. 73 +/- 62 mL in PEEP (p < .05). In patients with a focal loss of aeration, this underestimation was more pronounced: 18 +/- 56 mL vs. 127 +/- 140 mL in ZEEP (p < .01) and 85 +/- 161 mL vs. 322 +/- 292 mL in PEEP (p < .01). CONCLUSIONS: In patients with acute lung injury, an accurate computed tomography estimation of lung overinflation resulting from positive pressure mechanical ventilation requires high spatial resolution computed tomography sections, particularly when the lung morphology shows a focal loss of aeration.

Adult↗
PubMed2006

Quantitative assessment of tumour extraction from dermoscopy images and evaluation of computer-based extraction methods for an automatic melanoma diagnostic system.

The aims of this study were to provide a quantitative assessment of the tumour area extracted by dermatologists and to evaluate computer-based methods from dermoscopy images for refining a computer-based melanoma diagnostic system. Dermoscopic images of 188 Clark naevi, 56 Reed naevi and 75 melanomas were examined. Five dermatologists manually drew the border of each lesion with a tablet computer. The inter-observer variability was evaluated and the standard tumour area (STA) for each dermoscopy image was defined. Manual extractions by 10 non-medical individuals and by two computer-based methods were evaluated with STA-based assessment criteria: precision and recall. Our new computer-based method introduced the region-growing approach in order to yield results close to those obtained by dermatologists. The effectiveness of our extraction method with regard to diagnostic accuracy was evaluated. Two linear classifiers were built using the results of conventional and new computer-based tumour area extraction methods. The final diagnostic accuracy was evaluated by drawing the receiver operating curve (ROC) of each classifier, and the area under each ROC was evaluated. The standard deviations of the tumour area extracted by five dermatologists and 10 non-medical individuals were 8.9% and 10.7%, respectively. After assessment of the extraction results by dermatologists, the STA was defined as the area that was selected by more than two dermatologists. Dermatologists selected the melanoma area with statistically smaller divergence than that of Clark naevus or Reed naevus (P = 0.05). By contrast, non-medical individuals did not show this difference. Our new computer-based extraction algorithm showed superior performance (precision, 94.1%; recall, 95.3%) to the conventional thresholding method (precision, 99.5%; recall, 87.6%). These results indicate that our new algorithm extracted a tumour area close to that obtained by dermatologists and, in particular, the border part of the tumour was adequately extracted. With this refinement, the area under the ROC increased from 0.795 to 0.875 and the diagnostic accuracy showed an increase of approximately 20% in specificity when the sensitivity was 80%. It can be concluded that our computer-based tumour extraction algorithm extracted almost the same area as that obtained by dermatologists and provided improved computer-based diagnostic accuracy.

Algorithms↗
PubMed2004

Loss of consciousness: when to perform computed tomography?

OBJECTIVE: To determine the diagnostic value of physical examination (including neurologic exam) for positive computed tomography scan findings in children with closed head injury, Glasgow Coma Scale score 13-15 in the emergency department, and loss of consciousness or amnesia. DESIGN: Prospective descriptive study. SETTING: A large, tertiary, pediatric trauma center in San Diego County. PATIENTS: Children ages 2-16 with an isolated closed head injury, history of loss of consciousness or amnesia, and Glasgow Coma Scale 13-15 who were referred for pediatric trauma evaluation and received a head computed tomography as part of this evaluation. INTERVENTIONS: A standardized physical examination including skull/scalp exam, pupils, tympanic membrane, and brief neurologic exam was documented on each patient. MEASUREMENTS AND MAIN RESULTS: Subjects age 2-16 being evaluated by the pediatric trauma team for closed head injury with loss of consciousness or amnesia and Glasgow Coma Scale 13-15 received a standardized physical exam, noncontrast head computed tomography scan, and follow-up telephone call at 4-6 wks. Outcome variables include intracranial injury visualized on computed tomography scan and need for neurosurgical intervention. Ninety-eight subjects were enrolled in the study over a 1-yr period. Computed tomography scans revealed evidence of intracranial injury in 13 of 98 subjects (13%). Normal examination increased the probability of a normal computed tomography scan from.87 pretest to.90 posttest. Four of 38 subjects with normal examination were noted to have evidence of intracranial injury on computed tomography. These four subjects did not require neurosurgical intervention. Two of 98 subjects underwent neurosurgical procedures. One intracranial pressure monitor was placed for decreasing level of consciousness. One subject underwent surgical elevation of a depressed skull fracture. CONCLUSIONS: Detailed clinical examination is of no diagnostic value in detecting intracranial injuries found on head computed tomography scan. Patients with observed loss of consciousness or amnesia and Glasgow Coma Scale 13-15 should have a head computed tomography scan as part of their evaluation to avoid missing an intracranial injury.

Adolescent↗
PubMed2006

Use of reconstructed computed tomography for the assessment of joint spaces in the canine elbow.

OBJECTIVES: To assess the accuracy of reconstructed computed tomography for imaging canine elbow joint spaces. METHODS: Computed tomography scans of eight cadaveric elbows were obtained and reconstructed computed tomography images were formatted in the dorsal and sagittal planes. Humeroradial and humeroulnar joint space measurements were obtained from these images. Intra-observer and inter-observer variations in joint space measurements were assessed, as was the effect of specimen positioning (inter-image variation). After freezing, four elbows were sectioned in the dorsal plane and four in the sagittal plane. In addition to visual comparison of the frozen sections with reconstructed computed tomography images, joint space measurements were obtained from frozen sections and compared with those from reconstructed computed tomography images. Variation was assessed using statistical calculations and graphical techniques. RESULTS: Both inter-image and intra-observer analyses revealed good agreement and low variation between data sets. Inter-observer correlation was only moderate, though variation was low. Visually, the reconstructed computed tomography images accurately reflected the frozen section anatomy. Agreement between frozen section and reconstructed computed tomography joint space measurements was good, with minimal variation. CLINICAL SIGNIFICANCE: These results indicate that reconstructed computed tomography is capable of accurately imaging elbow joint spaces and precise joint space measurements can be obtained. Reconstructed computed tomography may be useful for determining joint space measurements and detecting elbow incongruencies in dogs with elbow dysplasia.

Animals↗