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Biomedical subjects

J R Galvin

Publications and source records attributed to J R Galvin.

At least 19 recordsLinked to original sources
PubMed1996

The utility of the frontal chest radiograph in the evaluation of chest drain placement.

AIM: To define the utility of the frontal chest radiograph in the assessment of chest drain position. PATIENTS AND METHODS: Fifty-six frontal chest radiographs in 45 patients with 61 chest drains (18 anterior, 9 interlobar, and 34 posterior position) were reviewed retrospectively to determine radiographic characteristics. RESULTS: Eighty-nine percent of the anterior drains demonstrated a curved appearance at the insertion site, while 50% of posterior drains and all interlobar drains were straight at the insertion site. A curved intrapleural drain was a common finding when positioned anteriorly and posteriorly (67% and 59%, respectively). Interlobar drains were often straight throughout their course (89%). The tips of interlobar drains were usually positioned at the hilum (89%). CONCLUSION: Results suggest that interlobar positioning can be suspected on the frontal chest radiograph. A curving chest drain with straight appearance at the insertion site was indicative of a posterior location.

Adult↗
PubMed1995

The virtual hospital. Providing multimedia decision support tools via the Internet.

Physicians in the clinical setting remain isolated from important sources of medical information. The authors have created a multimedia database known as The Virtual Hospital that improves access to current medical data, which is used to improve patient care decisions. The Virtual Hospital is a digital health sciences library stored on a server (computer) at The University of Iowa and delivered via the Internet to inexpensive personal computers in the workplace. The emerging standard of the World Wide Web is used to provide cross-platform distribution.

Computer Communication Networks↗
PubMed1995

A comparison of educational interventions. Multimedia textbook, standard lecture, and printed textbook.

OBJECTIVE: To compare the instructional effectiveness and efficiency of a pediatric multimedia textbook (MMTB) with that of a standard lecture and of a printed textbook in a prospective, interinstitutional study. DESIGN: Randomized, prospective cohort. SETTINGS: An urban and a rural medical school affiliated with tertiary care hospitals. POPULATION: Third- and fourth-year medical students from June 1992 to June 1993. INTERVENTIONS/OUTCOME MEASURES: Students were randomized to one of four treatment groups: (1) computer-aided instruction with MMTBs (n = 39), (2) traditional lecture (n = 39), (3) printed textbook (n = 39), or (4) a control group (n = 62). Only the control group was pretested. Following their randomized instruction, all groups were tested via a 26-question multiple-choice test. Statistical analysis was accomplished by analysis of variance of mean post-test scores. The amount of time that students spent with each educational intervention was recorded. RESULTS: Three hundred two students were eligible for the study, 267 entered the study, and 179 completed the study. The instructional effectiveness of the MMTB was greater than that of the lecture (P < .05), and it was the same as that of the printed textbook. All instructional methods were more effective than the control group (P < .05). The instructional efficiency of the MMTB was equal to that of the lecture and of the printed textbook. The subjective response to the MMTB instruction was positive. CONCLUSION: The MMTBs constitute an educationally sound alternative instructional method and have a promising future in medical education.

Adult↗
PubMed1995

Electron beam computed tomography: use in pulmonary embolectomy.

Proximal chronic pulmonary emboli with severe pulmonary hypertension were diagnosed by electron-beam computed tomography and Doppler echocardiography. After successful embolectomy, repeat examinations showed normal pulmonary artery pressures and patency. Electron beam computed tomography can noninvasively identify surgically treatable pulmonary emboli.

Adult↗
PubMed1995

Varied radiologic appearances of pulmonary aspergillosis.

Pulmonary aspergillosis represents a common, potentially lethal opportunistic infection that has four unique forms: allergic bronchopulmonary aspergillosis (ABPA), aspergilloma, and invasive and semi-invasive aspergillosis. In individuals who are at risk, pulmonary aspergillosis is characterized by a spectrum of clinical and radiographic findings that are intrinsically related to the status of the immune system or the presence of structural lung disease. ABPA, occurring almost exclusively in asthma patients, is characterized radiographically by fleeting pulmonary alveolar opacities caused by deposition of immune complexes and inflammatory cells within the lung parenchyma. Mucus plugging and bronchial wall thickening can be expected in time. Aspergilloma, occurring in patients with structural lung disease, typically appears radiographically as a focal intracavitary mass and is characterized initially by an increase in the wall thickness of a preexisting cavity or cyst. Invasive aspergillosis, which occurs primarily in profoundly immunocompromised patients, may exhibit nonspecific patchy nodular opacities or lobar-type air-space disease in cases with vascular invasion. Computed tomography may reveal a halo or ground-glass attenuation and is more accurate in the detection of early disease. Cavitation often develops with time and typically results in the air crescent sign. Semi-invasive aspergillosis is radiographically similar to the invasive form but differs in clinical course, being associated with mild immunosuppression or chronic illness and typically progressing over the course of months rather than weeks.

Aspergillosis↗
PubMed1995

Distributing an electronic thoracic imaging teaching file using the Internet, Mosaic, and personal computers.

A high quality film-based teaching file requires effort and expense to create and maintain. The effort is worthwhile because film collections are important vehicles for increasing a radiologist's personal data base of clinical experience. Expert clinical reasoning is to a large extent the process of comparing a current case to a data base of individual cases available in memory. A teaching file would be most helpful if it were available at the view box where it could be used to extend a radiologist's clinical experience. Unfortunately, a film-based file is confined to one area, usually remote from the view box. In addition, searching though a film file is difficult, the films wear out over time, and films are easily lost or stolen. Our goal is the creation of a thoracic imaging teaching file that solves these problems by providing a digital collection of images, videos, and text that can be used in the work place by many users simultaneously. The first part of this teaching file is now continuously available locally within our department and globally to users of the Internet.

Computer Communication Networks↗
PubMed1995

Hand-held digital books in radiology: convenient access to information.

Radiologists need constant, convenient access to current information throughout the course of their daily work. Today most learning in radiology is obtained from the printed word in books, journals, and teaching files, supplemented by the spoken word in lectures and conferences. Although learning from printed material and lectures has been proved efficacious over time, these media share the disadvantage of not being conveniently available for reference during the course of daily work at the alternator or in the examination room when accurate and up-to-date information is needed the most. As a result, many important questions about patient care go unanswered. We have developed a technique--hand-held digital books--to lower this barrier to searching and retrieval. When radiologists have a digital library that can be carried with them, they will be able to incorporate current radiology information into their daily decision making. We describe a technique for creating hand-held digital books and their future use in radiology.

Humans↗
PubMed1994

The multimedia textbook. A revolutionary tool for pediatric education.

Textbooks are now available via computers. These new electronic or multimedia textbooks appears similar to conventional books but differ in function. In addition to text and images, they contain video and audio clips and allow readers to interact with the content. Multimedia textbooks contain digital media, can be quickly and inexpensively updated and repurposed for lectures and handouts, and are available on-line via computer networks for distance learning. We present the concept of computer-generated multimedia text-books; describe their creation by an easy-to-use, sophisticated authoring system; and describe the underlying instructional design approach to guide future authors of multimedia textbooks.

Computer-Assisted Instruction↗
PubMed1994

Contrast-enhanced thin slice ultrafast computed tomography for the detection of small pulmonary emboli. Studies using autologous emboli in the pig.

RATIONALE AND OBJECTIVES: Ultrafast computed tomography (UFCT) has proven useful, but is of limited practical application in the diagnosis of central pulmonary embolism; however, its ability to detect more peripheral emboli has not been established. In this study, the use of contrast-enhanced UFCT images for the detection of autologous peripheral pulmonary emboli in the pig is evaluated. METHODS: A single autologous embolus measuring 0.7 x 1.5 cm was introduced into the superior vena cava of eight pigs. Contiguous, 3-mm axial UFCT images from the lung apex to the base were obtained before and after the introduction of the embolus. After scanning, the pigs were killed, and the thorax was removed intact and was frozen in a dry ice-alcohol mixture. Later, the thorax was sliced at 10-mm thicknesses, and the locations of the emboli were determined by a pulmonary pathologist blinded to the imaging results. Concomitantly, the locations of the emboli were determined by consensus of three chest radiologists blinded to the autopsy results. RESULTS: In 6 of 8 animals with emboli, the embolus location correlated exactly with the autopsy findings. In one, the embolus was on the same side, but 1.6 cm further distal. In the other, a marking suture was identified, but no clot was identified on the pathologic or UFCT examination. In the eight animals scanned before the introduction of the embolus, no embolus was found. Interobserver agreement was 100%. CONCLUSIONS: Ultrafast computed tomography has the potential to detect autologous emboli in second- to fourth-division pulmonary vessels. Further studies are needed to determine if in vivo emboli can be similarly visualized.

Animals↗
PubMed1994

The virtual hospital: a new paradigm for lifelong learning in radiology.

Medical training in radiology should be viewed as a continuum that begins in medical school and proceeds throughout the years in practice. Unfortunately, there are significant barriers to providing continuing medical education. One key barrier is the physical separation between the information source and the workplace. A multimedia medical library distributed via wide area networks has been developed that provides needed information at the point of use. The distribution software (Mosaic) that makes this project possible is found in the public domain.

Computer Communication Networks↗
PubMed1994

High-resolution CT-derived measures of lung density are valid indexes of interstitial lung disease.

To assess the validity of computer-assisted methods in analyzing the lung parenchyma imaged with high-resolution computed tomography (HRCT), we compared computer-derived estimates of lung density to other, more traditional, measures of parenchymal injury in 24 subjects with idiopathic pulmonary fibrosis (IPF) and 60 subjects with extensive occupational exposure to asbestos. Gray scale density histograms were constructed from the HRCT images. The gray scale histogram of both study groups was of a skewed unimodal distribution. However, compared with the asbestos-exposed subjects, the patients with IPF had a gray scale distribution that was significantly shifted to the right (greater density) and flatter. In a multivariate analysis, after controlling for age and cigarette smoking, we found that the mean and median gray scale densities were independently associated with the presence of moderate-to-severe dyspnea, a higher International Labour Office chest X-ray category, a lower forced vital capacity, and a higher concentration of macrophages and eosinophils in the bronchoalveolar lavage fluid. These factors accounted for > 70% of the variance of the mean and median gray scale densities. Interestingly, no differences in gray scale density measures were noted between patients with IPF and patients with asbestosis when these other factors were taken into account. Our results suggest that computer-derived density analysis of the lung parenchyma on the HRCT scan is a valid, clinically meaningful, and objective measure of interstitial lung disease.

Asbestosis↗
PubMed1994

Determinants of survival in idiopathic pulmonary fibrosis.

To identify the determinants of survival in patients with idiopathic pulmonary fibrosis (IPF), we performed a survival analysis on 74 subjects with IPF. The study subjects were on average 64 yr of age (range, 25 to 83 yr), 62% were male, and 29% were never smokers. A tissue diagnosis was made in 67 (91%) of our study subjects. These subjects were followed for a mean period of 4 yr (range, 1.4 to 118.8 months) after the onset of pulmonary symptoms. During the period of observation, 41 subjects died (median survival = 28.2 months) and 33 continue to survive (median follow-up period = 60.9 months). A univariate analysis demonstrated that diminished survival was significantly associated with male gender (hazard ratio = 1.98; 95% confidence interval [CI] = 1.01-3.85), a higher FEV1/FVC ratio (hazard ratio = 1.82 [per 10% increase in the FEV1/FVC ratio]; 95% CI = 1.21-2.73), a lower percent predicted FVC (hazard ratio = 0.74; 95% CI = 0.60-0.91), a lower percent predicted total lung capacity (TLC) (hazard ratio = 0.75; 95% CI = 0.60-0.94), a lower percent predicted diffusing capacity of carbon monoxide (DLCO) (hazard ratio = 0.69; 95% CI = 0.53-0.89), a higher ILO profusion category on chest radiograph (hazard ratio = 3.52; 95% CI = 1.58-7.87), and an enhanced release of prostaglandin E2 (PGE2) by cultured alveolar macrophages (hazard ratio = 1.32 [per 10 pm/ml of PGE2]; 95% CI = 1.07-1.62).(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchoalveolar Lavage Fluid↗
PubMed1994

Longitudinal changes in lung function among asbestos-exposed workers.

To prospectively identify the determinants of persistent or accelerated loss of lung function among workers occupationally exposed to asbestos and assess the relative contribution of cigarette smoking, asbestos-induced pleural fibrosis, and specific findings from bronchoalveolar lavage and high resolution CT scans, we examined the determinants of lung function changes in 117 subjects occupationally exposed to asbestos for at least 1 yr in a high exposure setting. A minimum of 20 yr was required between the first exposure to asbestos and entry into the study. Baseline studies included an independent assessment of dyspnea, lung volumes, diffusing capacity of carbon monoxide (DLCO), a chest radiograph, a high resolution CT (HRCT) scan, and bronchoalveolar lavage (BAL). Subjects were observed for an average of 2 yr (range, 0.5 to 4.0 yr), and lung function was measured on at least two separate occasions (mean, 4.1 separate tests). During the period of observation, there was an average 1.5% decrease in the TLC and a 2.5% decrease in the DLCO. In this longitudinal data set, after controlling for age, height, pack-years of cigarette smoking, and follow-up time, persistently lower measures of TLC were independently related to moderate to severe dyspnea (p = 0.005), diffuse pleural thickening (p = 0.007), and higher concentrations of fibronectin in BAL fluid (p = 0.01). Interstitial lung disease either on the chest radiograph or HRCT scan was not independently associated with persistently lower measures of TLC during the period of observation. However, none of the clinical variables we examined were associated with an accelerated decline in TLC.(ABSTRACT TRUNCATED AT 250 WORDS)

Asbestos↗
PubMed1994

Asbestos-induced pleural fibrosis and impaired exercise physiology.

To further assess the clinical significance of asbestos-induced pleural fibrosis, we performed cardiopulmonary exercise testing in 90 subjects who were exposed to asbestos. Of the 82 subjects without an abnormal resperate exercise, 35 had normal pleura, 33 had circumscribed pleural plaques, and 14 had diffuse pleural thickening. Interstitial fibrosis (International Labor Organization [ILO]. > or = 1/10) was present in 14 of 35 subjects with normal pleura, 13 of 33 subjects with circumscribed pleural plaques, and 2 of 14 subjects with diffuse pleural thickening. Although pleural fibrosis did not appear to be related to impaired respiratory function with exercise in our entire cohort, this finding was confounded by a higher proportion of interstitial fibrosis in subjects with normal pleura. In fact, among study subjects without asbestosis, significant decreases in gas exchange (higher VD/VT and increased alveolar-arterial oxygen pressure difference) were observed at maximal exercise among subjects with pleural fibrosis. Interestingly, neither a higher respiratory rate nor a lower VT/FVC ratio was observed among those with pleural fibrosis, suggesting that the mechanical effects of pleural fibrosis on the chest wall do not explain the increased VD/VT. Using multivariate analyses to control for potential confounders, regression models showed that pleural plaques (p = 0.04) and diffuse pleural thickening (p = 0.03) were independently associated with significant increases in dead space ventilation (VD/VT) with maximal exercise. These findings indicate that asbestos-induced pleural fibrosis is independently associated with decrements in gas exchange with maximal exercise and suggest that interstitial lung disease, not detected on the routine chest x-ray film, may be responsible for this abnormal response to exercise.

Asbestos↗
PubMed1994

The networked multimedia textbook: distributing radiology multimedia information across the Internet.

OBJECTIVE: The purpose of this project was to create an approach for global radiology multimedia publishing using the internet that would address the two largest problems facing radiology multimedia publishers today: the high percentage of radiologists who are computer novices and the variety of personal computers (Macintosh, Microsoft Windows/IBM-PC, X-Windows, Amiga) whose software is incompatible. MATERIALS AND METHODS: We developed a client/server approach to multimedia publishing, the networked multimedia textbook, that has a simple booklike user interface to facilitate use by computer novices. Once created, a networked multimedia textbook can be viewed on all current popular personal computers. The networked multimedia textbook is based on the internet, World-Wide Web, Mosaic, and Wide Area Information Servers software technologies, all of which are in the public domain. RESULTS: We created six radiology networked multimedia textbooks. CONCLUSION: This networked multimedia textbook approach for the global distribution of multimedia radiology information brings the benefits of multimedia publishing on the Internet to radiologists today.

Computer Communication Networks↗