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PubMed2004

Possible association between heavy computer users and glaucomatous visual field abnormalities: a cross sectional study in Japanese workers.

STUDY OBJECTIVE: To study the association between computer use and visual field abnormalities (VFA) and to assess whether heavy computer users have an increased risk of glaucoma. DESIGN: Cross sectional multicentre study. Subjects and observation procedures: A total of 10 202 randomly selected Japanese workers (mean (SD) age 43.2 (9.8) years) were screened for VFA using the frequency doubling technology perimetry (FDT-VFA), in addition to undergoing a general medical check up, and then ophthalmologically examined. Information about their computer use and refractive errors was obtained from a questionnaire and interview, respectively. MAIN RESULTS: As a result of FDT test, 522 and 8602 subjects were positive and negative for FDT-VFA, respectively. A significant (p = 0.004) interaction was found between computer use and refractive errors regarding the risk of FDT-VFA. In stratified analysis, heavy computer users with refractive errors showed a significant positive association with FDT-VFA (odds ratio (OR) = 1.74, 95% confidence interval (CI) 1.28 to 2.37), while those without refractive errors did not. Comparison of 165 subjects with an ophthalmological diagnosis of glaucoma and 2918 controls showed that the OR for glaucoma of heavy computer users with refractive errors was 1.82 (95% CI 1.06 to 3.12). Of 165 subjects with glaucoma, 141 had refractive errors, especially myopia (96.4%, 136 of 141). CONCLUSIONS: Although there are limitations to this study, such as its cross sectional design, heavy computer users with refractive errors seem to have an increased risk of FDT-VFA. Glaucoma might be involved in an underlying disease and myopia in a risk factor for FDT-VFA.

Adult↗
PubMed1983

Preoperative staging of lung cancer: accuracy of computed tomography versus mediastinoscopy.

Forty-four patients coming to surgery for carcinoma of the bronchus underwent preoperative staging of the mediastinum by computed tomography (CT scanning) and surgical exploration of the mediastinum by cervical mediastinoscopy or left anterior mediastinotomy or both. Where mediastinal nodes were affected the sensitivity and specificity of computed tomography was inferior to that of mediastinoscopy (57% and 85% versus 71% and 100%). The sensitivity of computed tomography in predicting mediastinal invasion was superior to that of mediastinoscopy (77% v 46%), especially in the case of lower-lobe tumours (67% v 17%). Mediastinoscopy had the considerable advantage of 100% specificity. In the assessment of hilar lymphadenopathy computed tomography had a sensitivity of 38% and a specificity of 64%. In cases where computed tomography showed a normal mediastinum or enlargement of the hilar glands only, mediastinal exploration conferred no additional information and could have been omitted. A computed tomography scan showing mediastinal abnormality is an indication for mediastinoscopy and not a contraindication to surgery. In 23 patients computed tomography showed some abnormality of the mediastinum, confirmed at mediastinoscopy in 12 cases. The remaining 11 patients underwent thoracotomy, resection being carried out in nine. Postsurgical staging showed that six of these tumours were N0 lesions without invasion; in two further N0 cases there was a minor degree of mediastinal invasion which did not prevent resection, and the remaining tumour was N1 without invasion.

Aged↗
PubMed1992

High resolution computed tomography as a predictor of lung histology in systemic sclerosis.

BACKGROUND: The relative proportions of fibrosis and inflammation seen by open lung biopsy examination is a predictor of disease outcome in fibrosing alveolitis. This study was designed to assess the ability of high resolution computed tomography to predict the histological appearance of open lung biopsy specimens from patients with systemic sclerosis. METHODS: Twenty abnormal biopsy specimens from 12 patients were assessed; abnormalities were categorised as fibrotic (fibrosis exceeding inflammation) or inflammatory (inflammation equal to or exceeding fibrosis). Computed tomography appearances were scored for the lobe from which the biopsy specimen was taken; scans were graded from parenchymal opacification alone through to a reticular pattern alone. RESULTS: Two lobar appearances were identified on computed tomograms: amorphous parenchymal opacification equal in extent to reticulation (grade 3) and a predominantly reticular pattern (grade 4). There was a significant association between a fibrotic histological appearance and a grade 4 computed tomogram, and between an inflammatory histological appearance and a grade 3 computed tomogram. Computed tomography grade 4 was associated with a fibrotic histological appearance in 12 out of 13 lobes, and grade 3 with an inflammatory histological appearance in four out of seven lobes. CONCLUSION: Computed tomography discriminated between biopsy specimens that were predominantly fibrotic and a smaller group with a larger amount of inflammation.

Adult↗
PubMed1993

Advanced computer applications in radiology: clinical applications.

Computers play a major role in bridging the gap between image generation and patient care by providing enhanced images that better meet the needs of referring physicians. Spiral computed tomography allows generation of three-dimensional images that are not affected by motion artifact. Volume rendering, a three-dimensional reconstruction algorithm, yields images free of computer-generated artifacts and superior in quality. Currently, technologic computer advances play an important role in three clinical areas: orthopedic applications, oncologic applications, and prosthetic design. Three-dimensional imaging is especially valuable in fracture assessment because it allows exploration of image data to define the location of fracture fragments, the integrity of the joint space, and any possible displacement. With three-dimensional imaging, the extent of tumor spread into adjacent soft tissue or involvement of blood vessels can be determined, even in difficult anatomic areas. Volume rendering and increased computer speed allow greatly improved treatment planning for radiation therapy and custom design of orthopedic prostheses. Through the mutual understanding of goals between physicians and computer scientists, the computer can reach its full potential in medicine, resulting in improved patient care.

Diagnostic Imaging↗
PubMed2001

Potential of computer-aided diagnosis to reduce variability in radiologists' interpretations of mammograms depicting microcalcifications.

PURPOSE: To evaluate whether computer-aided diagnosis can reduce interobserver variability in the interpretation of mammograms. MATERIALS AND METHODS: Ten radiologists interpreted mammograms showing clustered microcalcifications in 104 patients. Decisions for biopsy or follow-up were made with and without a computer aid, and these decisions were compared. The computer was used to estimate the likelihood that a microcalcification cluster was due to a malignancy. Variability in the radiologists' recommendations for biopsy versus follow-up was then analyzed. RESULTS: Variation in the radiologists' accuracy, as measured with the SD of the area under the receiver operating characteristic curve, was reduced by 46% with computer aid. Access to the computer aid increased the agreement among all observers from 13% to 32% of the total cases (P <.001), while the kappa value increased from 0.19 to 0.41 (P <.05). Use of computer aid eliminated two-thirds of the substantial disagreements in which two radiologists recommended biopsy and routine screening in the same patient (P <.05). CONCLUSION: In addition to its demonstrated potential to improve diagnostic accuracy, computer-aided diagnosis has the potential to reduce the variability among radiologists in the interpretation of mammograms.

Biopsy↗
PubMed1989

Computed arthrotomography as an adjunct to pediatric arthrography.

Computed arthrotomography was compared with conventional arthrography in ten cases and with both pluridirectional arthrotomography and conventional arthrography in five cases. Six elbows, five hips, three ankles, and one wrist were examined. Indications included pain, locking, congenital hip dislocation, posttraumatic joint deformity, and postinfectious joint deformity. Compared with conventional arthrography, computed arthrotomography provided additional information in ten of 15 (67%) cases and provided the same information in four cases. Arthrography and computed arthrotomography were complementary in one case. Compared with pluridirectional arthrotomography, computed arthrotomography provided additional information in two of five (40%) cases. In the remaining three cases, computed arthrotomography and pluridirectional arthrotomography provided equal information. In no case did pluridirectional arthrotomography provide additional information. Computed arthrotomography was useful in demonstrating loose bodies, differentiating air bubbles from loose bodies, and determining the intra- or extraarticular location of ossific densities. Computed arthrotomography appears to be a useful adjunct to arthrography in detecting loose bodies and in evaluating anatomically complex cases.

Adolescent↗
PubMed1996

Mottle on computed radiographs of the chest in pediatric patients.

PURPOSE: To investigate the relationship between radiation exposure and perceived mottle at bedside pediatric chest examinations performed with screen-film and computed radiographic techniques. MATERIALS AND METHODS: In a pediatric intensive care unit, chest radiographs were obtained with both computed radiography (60 radiographs) and a 600-speed screen-film system (14 radiographs). The relative radiation exposure was estimated by using the sensitivity value obtained in the processing of each computed radiograph. Five radiologists assessed the mottle present in the computed radiographs and screen-film images. RESULTS: For computed radiographs, the perceived level of mottle was inversely related to radiation exposure. For the same radiation exposure, the perceived mottle on computed radiographs was significantly higher than that on screen-film images (P < .001 for small cassettes; P < .01 for large cassettes). CONCLUSION: Pediatric computed radiography of the chest requires approximately twice the exposure of a 600-speed screen-film system to attain the same level of mottle.

Child↗
PubMed1999

Computed radiography versus screen-film radiography: detection of pulmonary edema in a rabbit model that simulates neonatal pulmonary infiltrates.

PURPOSE: To determine if computed radiography is equivalent to screen-film radiography in depicting pulmonary edema and to determine if radiation exposure can be reduced with computed radiography while maintaining equivalent diagnostic accuracy for pulmonary edema. MATERIALS AND METHODS: Oleic acid was intravenously injected into three rabbits at each of four doses: 0, 0.02, 0.04, and 0.06 mL/kg. Two hours later, chest computed radiographs and screen-film radiographs were obtained at 60 kVp and 1.1 mAs. Additional computed radiographs were obtained after reducing milliampere seconds or by reducing milliampere seconds and increasing the kilovolt peak, which reduced bone marrow exposure by up to 20%. The presence of pulmonary opacities, "truth," was established by the wet-dry weight ratio and by chest computed tomography (CT). The radiographs were masked and randomized. Four observers rated the images for the presence of parenchymal opacities with a dichotomous score and judged the quality of the radiographs on a scale from 1 (worst) to 6 (best). Cochran Q tests and McNemar tests were used to analyze the differences in paired comparisons. Image quality was evaluated with logistic regression analysis. RESULTS: There was no significant difference between truth and observer ability to detect opacity for either modality or for any exposure (P > .05). There was no significant difference between computed radiography and screen-film radiography for image quality (P > .05). CONCLUSION: Computed radiography is equivalent to screen-film radiography in the detection of pulmonary edema. Radiation exposure reduction of 20% can be achieved without affecting pulmonary edema detection or image quality.

Animals↗
PubMedDate not supplied

Clinical validity of negative helical computed tomography for clinical suspicion of pulmonary embolism.

BACKGROUND: Helical computed tomography has been introduced for the diagnosis of pulmonary embolism. OBJECTIVE: To determine the clinical safety of withholding anticoagulant treatment in patients with suspicion of pulmonary embolism and negative helical computed tomography study. METHODS: During a 9-month period, we performed a prospective study including 209 consecutive patients who underwent helical computed tomography for clinical suspicion of pulmonary embolism. In 53 patients (25.5%), helical computed tomography was diagnostic for pulmonary embolism, and in 24 patients (11.5%) it was indeterminate. In 132 patients (63%), the examination was negative for pulmonary embolism and no anticoagulation treatment was given. A clinical 3-month follow-up was carried out. During this period, 29 patients (22%) were excluded because anticoagulation therapy was initiated for other reasons, or because other diagnostic techniques were performed for pulmonary embolism. Four patients were lost in the 3-month period. In the end, 99 patients (75%) were included in the clinical follow-up. RESULTS: Out of the 99 patients, 9 (9%) died during the 9-month follow-up, the cause of death in each case was not due to thromboembolic venous disease. No venous thromboembolic events were detected in the other 90 patients. Negative predictive value of helical computed tomography for pulmonary embolism was 99.09% (95% CI, 95.03-99.97%). CONCLUSIONS: In patients with clinical suspicion of pulmonary embolism and initial negative helical computed tomography from whom anticoagulants are withheld, no thromboembolic disease was detected in a 3-month follow-up. We consider helical computed tomography an effective method for ruling out pulmonary embolism as well as a front-line tool for diagnosis.

Age Distribution↗
PubMed1981

Computer-assisted karyotyping system of banded chromosomes.

The banding automatic system (BAS) we describe in this paper is a computer-assisted karyotyping system suitable for the analysis of both normal and abnormal karyotypes in banded chromosome specimens. In the BAS system recognition of the various features and constituents of the chromosomes is performed by an operator, whereas chromosome identification and classification are entrusted to a computer. The connection between operator and computer is the CYGEN1 program, which is tailored to distinguish chromosome morphology on the basis of the operator input band patterns alone. The karyotyping operation is therefore significantly speeded up: the operator simply has to read through a certain number of banded metaphases, encoding band-pattern data to the computer. The machine signals when the operation has gone through the whole karyotype or, for instance, when chromosomes are missing or present in extra number above the significance level from the analyzed metaphases. Chromosome identification and classification are then carried out by the computer, which performs as a real-time recognizing key. Moreover, the data being accumulated in the computer will provide a file of cytogenetic records accessible to the operator, as well as to the computer, for further diagnostic operations. The efficacy of the BAS system is demonstrated for the diagnosis of various structural aberrations, including a complex translocation. The processing of 20 metaphases by the method described takes 40-45 min, and a cytogenetic technician can make effective use of the system after 25-30 h of intensive training.

Chromosome Aberrations↗
PubMed1990

Correlation of clinical and computed tomographic findings in stroke patients.

We evaluated the correlation between clinical features and computed tomographic findings in a prospective study of 1,191 consecutive patients with acute cerebrovascular disease seen during 1 year. In the 386 patients in whom symptoms and signs initially suggested a cerebrovascular disorder, computed tomography revealed a relevant lesion in 154 (hemorrhagic in 52 [33.8%], ischemic in 102 [66.2%]) and a significant nonstroke abnormality in 14 (3.1%). Among the remaining 805 patients with symptoms and signs suggesting some central nervous system disorder other than stroke, computed tomography revealed a cerebrovascular lesion in 38 (4.7%); 35 of these lesions were ischemic. The computed tomographic findings was compatible with the final clinical diagnosis in 192 (84.2%) of the 228 patients with lesions. In the entire sample of 1,191 patients, a cerebrovascular disorder would have been missed in 38 (3.2%) without computed tomography. On the other hand, computed tomography failed to visualize a cerebrovascular lesion in 40 patients in whom such a lesion was clinically obvious. Our results emphasize that both careful neurologic assessment and a policy of early computed tomography are of crucial importance in the diagnosis of stroke and for therapeutic considerations.

Adolescent↗
PubMed1990

Comparison of two-dimensional echocardiography and ultrafast cardiac computed tomography for evaluating intracardiac thrombi in cerebral ischemia.

Two-dimensional echocardiography has a high specificity for the detection of intracardiac thrombi, but technically difficult studies are often encountered. Ultrafast cardiac computed tomography may be useful in such cases. Using transthoracic two-dimensional echocardiography and ultrafast cardiac computed tomography, we studied 36 patients with cerebral ischemia; one patient had the studies performed on two occasions, making a total of 37 sets of studies. Technical difficulties occurred in 12 echocardiographic (32%) and two ultrafast cardiac computed tomographic (5%) studies. The two techniques agreed in 29 sets of studies (78%). Among the eight discrepant sets of studies, two-dimensional echocardiography was positive for a left ventricular thrombus while ultrafast cardiac computed tomography was negative in three and equivocal in one and echocardiography was equivocal while ultrafast cardiac computed tomography was negative in two and positive in one. In the latter case, a left ventricular thrombus was confirmed at autopsy. In the other discrepant set of studies echocardiography was negative while ultrafast cardiac computed tomography revealed a left atrial and appendage thrombus. Because of its ease of performance and safety, two-dimensional echocardiography is the appropriate initial screening test for left ventricular thrombus. Ultrafast cardiac computed tomography can provide additional information in patients with technically difficult or equivocal two-dimensional echocardiographic studies or patients with cardiac disorders predisposing to atrial thrombi formation.

Adult↗
PubMed1996

Variability of magnetic resonance angiography and computed tomography angiography in grading middle cerebral artery stenosis.

BACKGROUND AND PURPOSE: Magnetic resonance angiography and computed tomography angiography are new, noninvasive methods to provide images of the cerebral vasculature. The reliability of magnetic resonance angiography and computed tomography angiography when used to grade middle cerebral artery stenosis remains to be established. We sought to study the interobserver and intraobserver variabilities of magnetic resonance angiography and computed tomography angiography in grading middle cerebral artery stenosis. METHODS: A total of 50 middle cerebral arteries in 25 patients were studied with magnetic resonance angiography and computed tomography angiography. All patients had a history of ischemic stroke. The films were read independently by two observers on separate occasions. Films were shown again to the same observer 4 weeks after the first reading. The degree of middle cerebral artery stenosis was categorized into four grades: normal/mild, moderate, severe, and occluded. The interobserver and intraobserver variabilities were calculated by the kappa statistic method. RESULTS: Interobserver variability for grading middle cerebral artery stenosis was good (kappa = 0.78) for magnetic resonance angiography and moderate (kappa = 0.51) for computed tomography angiography. There was perfect agreement between two observers in 86% of the vessels shown in magnetic resonance angiography and in 76% of the vessels shown in computed tomography angiography. Intraobserver variability for both imaging methods was good, with the kappa value in the range of 0.70 to 0.76. CONCLUSIONS: Our results suggest that according to our protocol, magnetic resonance angiography is more reliable than computed tomography angiography in grading middle cerebral artery stenosis.

Adult↗
PubMed2001

Use of audio computer-assisted self-interviews to assess tuberculosis-related risk behaviors.

UNLABELLED: The objective of this study was to compare self-reported tuberculosis and human immunodeficiency virus (HIV) risk factors obtained from computer-assisted questionnaires and interviewer-assisted questionnaires among participants of a needle exchange program. Between June 1998 and May 1999, needle exchange program participants requesting tuberculosis screening underwent interviews regarding demographics and risk factors for tuberculosis and HIV infection. The first 190 participants underwent traditional interviewer-assisted questionnaires, whereas the remaining 92 underwent computer-assisted questionnaires. Data were analyzed by interview technique using odds ratios (OR) and multiple logistic regression. Among 282 participants, demographic characteristics, health status, HIV serostatus, visits to homeless shelters, alcohol intake, and cigarette smoking were all similar by interview technique. However, respondents receiving computer-assisted questionnaires were more likely than those receiving interviewer-assisted questionnaires to report smoking marijuana (OR = 5.56), crack (OR = 1.88), and heroin (OR = 2.60); as well as sharing cocaine smoking equipment (OR = 4.49), sharing heroin smoking equipment (OR = 2.85), "shotgunning" (OR = 4.48), and visiting crack houses (OR = 4.39). In the final multivariate model, respondents receiving computer-assisted questionnaires were more likely to report "shotgunning" and visiting a crack house relative to respondents receiving interviewer-assisted questionnaires. In conclusion, increased odds of high-risk behaviors for tuberculosis and HIV infection among computer-assisted questionnaire respondents support the use of computer-assisted questionnaires to ascertain risk behavior data for both tuberculosis and HIV. KEYWORDS: tuberculosis; HIV; self-report; drug use; computer-assisted

Baltimore↗
PubMed1986

Why doctors don't use computers: some empirical findings.

The attitudes of 148 medical students, 141 residents, and 644 practising physicians towards computer applications in medicine were studied. The results indicate that physicians recognize the potential of computers to improve patient care, but are concerned about the possibility of increased governmental and hospital control, threats to privacy, and legal and ethical problems. In general, all three groups are uncertain as to the potential effects of computers on their traditional professional role and on the organization of practice. Practising physicians, however, express more concern about these potential effects of computers than do medical students and residents. While attitudes appear to be somewhat independent of prior computer experience, they significantly affect the extent to which physicians use a computer-based hospital information system. This may be a major reason for the slow introduction of clinical computer systems.

Attitude of Health Personnel↗
PubMedDate not supplied

Current computer use by diabetes educators.

PURPOSE: The purpose of this study was to ascertain diabetes educators' current use of computer technologies. METHODS: The study population consisted of 279 randomly selected certified diabetes educators, all of whom were members of the American Association of Diabetes Educators. Participants were asked to complete the Attitudes Toward Patient Education Technology instrument. RESULTS: Descriptive findings showed that most educators (89.6%) have access to computers and use them primarily for word processing (43%). Nearly 30% of participants had never accessed the Internet, and no significant difference was noted when this variable was categorized by age. In addition, age and gender were not significant predictors of computer use, although age was significantly related to computer ownership. Patient access and organizational issues were the primary barriers to computer use in patient education. CONCLUSIONS: These findings provide further understanding of diabetes educators' computer use and integration of computer technology in the patient education process.

Allied Health Personnel↗
PubMed1994

Congenital perilymphatic fistula: computed tomography appearance of middle ear and inner ear anomalies.

Congenital perilymphatic fistula is an abnormal communication between the inner ear and middle ear. Inner ear anomalies have been described on computed tomography scans. Middle ear anomalies have been found at surgery; the most frequent are anomalies of the stapes and round window. This retrospective study describes the appearance of the inner and middle ear on computed tomography scans, and of the middle ear at surgery, in 10 patients (15 ears) in whom perilymphatic fistula was found at surgery. Twelve of 15 stapes were abnormal at surgery; 4 of these 12 (33%) could be seen on computed tomography scans. Two stapes normal at surgery were normal on computed tomography. Three round windows were abnormal at surgery; none of these was seen on computed tomography scans. There were also four dysplastic cochleas, four dysplastic vestibules, and three dilated vestibular aqueducts. Computed tomography scans identified an abnormal inner ear, middle ear, or both in 8 (53%) of the 15 ears with perilymphatic fistula. An inner ear or middle ear anomaly on computed tomography may heighten clinical suspicion of congenital perilymphatic fistula.

Adolescent↗
PubMed1984

Relationships between computer use and pharmacists' professional behavior.

Relationships between use of pharmacy computers and performance of selected professional activities were investigated, via a survey of southern Michigan pharmacists. Respondents included users of two major computer systems as well as pharmacists who do not use computers. A net response rate of 65.7 percent (213 usable questionnaires) was achieved. In general, computer users reported encountering more drug-related problems than did nonusers and more frequent contacts with prescribers for drug-therapy problems. Little difference was found between the two groups in regard to patient counseling activities, except that computer users were more likely to use auxiliary labels. When responses from users of the two computer systems were examined separately, results suggested that one of the systems contributed positively to certain aspects of pharmacists' professional activities while the other system had little influence. These results indicate that it may not be possible to state general conclusions about the effect of computers on the professional practice of pharmacy.

Computers↗