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Biomedical subjects

E L Siegel

Publications and source records attributed to E L Siegel.

At least 19 recordsLinked to original sources
PubMed2001

Muscle size responses to strength training in young and older men and women.

OBJECTIVES: To examine the possible influences of age and gender on muscle volume responses to strength training (ST). DESIGN: Prospective intervention study. SETTING: University of Maryland Exercise Science and Wellness Research Laboratories. PARTICIPANTS: Eight young men (age 20-30 years), six young women (age 20-30 years), nine older men (age 65-75 years), and ten older women (age 65-75 years). INTERVENTION: A 6-month whole-body ST program that exercised all major muscle groups of the upper and lower body 3 days/week. MEASUREMENTS: Thigh and quadriceps muscle volumes and mid-thigh muscle cross-sectional area (CSA) were assessed by magnetic resonance imaging before and after the ST program. RESULTS: Thigh and quadriceps muscle volume increased significantly in all age and gender groups as a result of ST (P < .001), with no significant differences between the groups. Modest correlations were observed between both the change in quadriceps versus the change in total thigh muscle volume (r = 0.65; P < .001) and the change in thigh muscle volume versus the change in mid-thigh CSA (r = 0.76, P < .001). CONCLUSIONS: The results indicate that neither age nor gender affects muscle volume response to whole-body ST. Muscle volume, rather than muscle CSA, is recommended for studying muscle mass responses to ST.

Adult↗
PubMed2001

Radiologists' productivity in the interpretation of CT scans: a comparison of PACS with conventional film.

OBJECTIVE: We compared radiologists' times in the interpretation of CT using hardcopy films with the interpretation using a soft-copy picture archiving and communication system (PACS) computer workstation. MATERIALS AND METHODS: One hundred CT examinations were selected at random and reviewed by four board-certified radiologists experienced in soft-copy interpretation. We performed time-motion analysis to determine the total time required to display, interpret, and dictate the individual findings of CT using conventional hard-copy interpretation on a viewbox and soft-copy interpretation, using a four-monitor high-resolution (2048 x 1536 pixel) workstation. RESULTS: Time-motion analysis showed a reduction of 16.2% in the overall time required for soft-copy interpretation of CT compared with that of film. Time savings with soft-copy interpretation were observed for all four participating radiologists. The benefit of soft-copy interpretation was increased for examinations in which there were comparison studies. CONCLUSION: We found that soft-copy interpretation of CT using a PACS workstation requires less time than interpretation using conventional film hung on a viewbox. The transition to filmless imaging has the potential to improve radiologists' productivity and report-turnaround time.

Efficiency↗
PubMed2000

Challenges associated with interfacing computed tomography to a picture archiving and communication system at the Baltimore Veterans Affairs Medical Center--a historical perspective.

The interfacing of digital image acquisition modalities to the picture archiving and communication system (PACS) plays a major part in the conversion from a traditional film-based radiology practice to one that relies almost entirely on soft-copy reading. The Baltimore Veterans Affairs Medical Center (VAMC) is one of the first filmless hospitals in the world. Since 1993, it has used computed tomography (CT) scanners connected to a commercial PACS to provide digitized patient images for filmless reading. Over the years, the evolution of Digital Imaging and Communications in Medicine (DICOM) standards, advances in networking technologies, and enhancements in PACS and hospital information system (HIS) software have greatly improved this system's robustness and patient/study identification accuracy. The result has been a major increase in productivity.

Baltimore↗
PubMed2000

Frequency and impact of high-resolution monitor failure in a filmless imaging department.

The purpose of this study was to assess the image quality and the rate of failure of the high-resolution (2,048 x 1536 pixel) monitors used for primary diagnosis in a filmless radiology department and to analyze the type of problems encountered as well as the action taken to repair the monitors. Data were collected from Picture Archival and Communication System (PACS) service logs to determine rates of monitor adjustment and replacement, the symptoms reported, and the action taken. Additionally, random surveys of the high-resolution monitors were performed using a standard test pattern to assess spatial and contrast resolution in the center and outer corners of the monitors. Analysis of monitor service records showed a high rate of monitor replacement (41% per year) resulting in a relatively short "life expectancy" (defined as average time required before replacement) of 2.4 years. Random surveys of monitor quality using a standard test pattern showed suboptimal image quality in approximately 54% of the monitors with moderate image quality degradation present in at least one region of 27% of the high-resolution monitors, despite our vendor's quality control program. The results of this study support our subjective impression and those of other colleagues in the PACS community of an unacceptably high monitor failure rate and persistent image quality problems with 2,000 pixel monitors used for primary diagnosis. The relatively high incidence of suboptimal quality monitors suggests that more frequent quality control should be performed using a test pattern particularly given the fact that radiologists often are unable to discern degradation of monitor performance using clinical images. The high incidence of problems with image quality on high-resolution monitors indicates that vendors need to develop better quality control in monitor design and testing. Radiologists should review briefly a test pattern on each monitor at the beginning of each day. A computer program should be incorporated into the PACS, which asks radiologists to evaluate a test pattern and records the results in a central database, which is communicated to the service engineers. Further studies should be evaluated to determine the clinical impact of monitor image degradation, which is relatively easily seen using a test pattern but may be difficult to discern on clinical images. Requests for proposals (RFPs) for PACS and service contracts must specify carefully requirements for monitor image quality and conditions under which the vendor is required to replace these monitors.

Computer Terminals↗
PubMed2000

Effects of age, gender, and myostatin genotype on the hypertrophic response to heavy resistance strength training.

BACKGROUND: Because of the scarcity of data available from direct comparisons of age and gender groups using the same relative training stimulus, it is unknown whether older individuals can increase their muscle mass as much as young individuals and whether women can increase as much as men in response to strength training (ST). In addition, little is known about whether the hypertrophic response to ST is affected by myostatin genotype, a candidate gene for muscle hypertrophy. METHODS: Eleven young men (25 +/- 3 years, range 21-29 years), 11 young women (26 +/- 2 years, range 23-28 years), 12 older men (69 +/- 3 years, range 65-75 years), and 11 older women (68 +/- 2 years, range 65-73 years) had bilateral quadriceps muscle volume measurements performed using magnetic resonance imaging (MRI) before and after ST and detraining. Training consisted of knee extension exercises of the dominant leg three times per week for 9 weeks. The contralateral limb was left untrained throughout the ST program. Following the unilateral training period, the subjects underwent 31 weeks of detraining during which no regular exercise was performed. Myostatin genotype was determined in a subgroup of 32 subjects, of which five female subjects were carriers of a myostatin gene variant. RESULTS: A significantly greater absolute increase in muscle volume was observed in men than in women (204 +/- 20 vs 101 +/- 13 cm3, p < .01), but there was no significant difference in muscle volume response to ST between young and older individuals. The gender effect remained after adjusting for baseline muscle volume. In addition, there was a significantly greater loss of absolute muscle volume after 31 weeks of detraining in men than in women (151 +/- 13 vs 88 +/- 7 cm3, p < .05), but no significant difference between young and older individuals. Myostatin genotype did not explain the hypertrophic response to ST when all 32 subjects were assessed. However, when only women were analyzed, those with the less common myostatin allele exhibited a 68% larger increase in muscle volume in response to ST (p = .056). CONCLUSIONS: Aging does not affect the muscle mass response to either ST or detraining, whereas gender does, as men increased their muscle volume about twice as much in response to ST as did women and experienced larger losses in response to detraining than women. Young men were the only group that maintained muscle volume adaptation after 31 weeks of detraining. Although myostatin genotype may not explain the observed gender difference in the hypertrophic response to ST, a role for myostatin genotype may be indicated in this regard for women, but future studies are needed with larger subject numbers in each genotype group to confirm this observation.

Adult↗
PubMed2000

Effect of filmless imaging on the utilization of radiologic services.

PURPOSE: To determine the effect of a large-scale picture archiving and communication system (PACS) on in- and outpatient utilization of radiologic services. MATERIALS AND METHODS: Data were collected at the Baltimore Veterans Affairs (VA) Medical Center (BVAMC) before and after implementation of an enterprise-wide PACS; the numbers and types of imaging examinations performed for fiscal years 1993 and 1996 were evaluated. These data were compared with those from a similar academic medical center, the Philadelphia VA Medical Center (PVAMC), and with aggregate data obtained nationally for all VA hospitals over comparable periods. RESULTS: Inpatient utilization, defined as the number of examinations per inpatient day, increased by 82% (from 0.265 to 0.483 examinations per patient day) after a transition to filmless operation at BVAMC. This is substantially greater than the increases of 38% (from 0.263 to 0.362 examinations per patient day) and 11% (from 0.190 to 0.211 examinations per patient day) at the film-based PVAMC and nationally, respectively. Outpatient utilization, defined as the number of examinations per visit, increased by 21% (from 0.108 to 0.131 examinations per visit) at BVAMC, compared with a 1% increase (from 0.087 to 0.088 examinations per visit) at PVAMC and a net decrease of 19% (from 0. 148 to 0.120 examinations per visit) nationally. CONCLUSION: The transition to filmless operation was associated with increases in inpatient and outpatient utilization of radiologic services, which substantially exceeded changes at PVAMC and nationally over the same interval.

Academic Medical Centers↗
PubMed2000

Liver and bone window settings for soft-copy interpretation of chest and abdominal CT.

OBJECTIVE: We evaluated whether the use of multiple window and level settings on a soft-copy workstation improves diagnostic accuracy on chest and abdominal CT. We hypothesized that routinely using window and level settings during soft-copy interpretation would beneficially affect the final diagnosis without compromising efficiency. MATERIALS AND METHODS: Two hundred three randomly selected abdominal and chest CT scans were interpreted by three radiologists using a four-monitor soft-copy workstation (images per screen, nine; resolution, 2K). After the initial interpretations, all scans were reevaluated by the same radiologists using additional liver and bone window and level settings. Differences in conspicuity and characterization of abnormalities were graded on a three-point scale. RESULTS: Conspicuity and characterization of abnormalities were improved in 67% of abnormal findings (81/121; p = 0.01). Improvement (a finding that substantially affected the final diagnosis) was present in 18% of abnormal findings (22/121; p = 0.04). On average, the evaluation of images at multiple window and level settings required an additional 40 sec per case. CONCLUSION: The use of multiple window and level settings during soft-copy interpretation resulted in improved lesion detectability and characterization with greater diagnostic efficacy. Using soft-copy workstations, radiologists can evaluate images using multiple settings without compromising efficiency.

Bone Diseases↗
PubMed1999

Challenges associated with the incorporation of digital radiography into a picture archival and communication system.

Digital radiography (DR) has recently emerged as an attractive alternative to computed radiography (CR) for the acquisition of general radiographic studies in a digital environment. It offers the possibility of improved spatial and contrast resolution, decreased radiation dose due to improved efficiency of detection of x-ray photons, and perhaps most importantly, holds out the promise of increased technologist productivity. To achieve maximum efficiency, DR must be completely integrated into existing information systems, including the hospital and radiology information systems (HIS/RIS) and, when present, the picture archival and communication system (PACS). The early experience with the integration of DR at the Baltimore Veterans Affairs Medical Center (VAMC) has identified several challenges that exist to the successful integration of DR. DR has only recently been defined as a separate Digital Imaging and Communications in Medicine (DICOM) modality and images obtained will, at first, be listed under the category of CR. Matrix sizes with some DR products on the market exceed the current size limitations of some PACS. The patient throughput may be substantially greater with DR than with CR, and this in combination with the larger size of image files may result in greater demands for network and computer performance in the process of communication with the HIS/RIS and PACS. Additionally, in a hybrid department using both CR and DR, new rules must be defined for prefetching and display of general radiographic studies to permit these examinations to be retrieved and compared together. Advanced features that are planned for DR systems, such as dual-energy subtraction, tomosynthesis, and temporal subtraction, will likely require additional workstation tools beyond those currently available for CR.

Computer Communication Networks↗
PubMed1999

MammoWeb continuing medical education (CME): a web-based breast imaging CME program.

The ubiquity of the world-wide web allows unique educational opportunities for continuing medical education (CME). We have designed a comprehensive breast imaging CME curriculum to permit individual physicians in their homes or offices to use personal computers to ease the burden of this process. Category 1 CME credits can be earned off-hours without having the physician travel out of town. In addition, since the course is computer-based, the overall costs to the participant are substantially reduced. The program can be updated on an ongoing basis to include new technology or to provide additional information requested by the users.

Breast Diseases↗
PubMed1999

Elevated urine uranium excretion by soldiers with retained uranium shrapnel.

The use of depleted uranium in munitions has given rise to a new exposure route for this chemically and radioactively hazardous metal. A cohort of U.S. soldiers wounded while on or in vehicles struck by depleted uranium penetrators during the Persian Gulf War was identified. Thirty-three members of this cohort were clinically evaluated, with particular attention to renal abnormalities, approximately 3 y after their injury. The presence of retained shrapnel was identified by x ray, and urine uranium concentrations were measured on two occasions. The absorption of uranium from embedded shrapnel was strongly suggested by measurements of urine uranium excretion at two time intervals: one in 1993/1994 and one in 1995. Mean urine uranium excretion was significantly higher in soldiers with retained shrapnel compared to those without shrapnel at both time points (4.47 vs. 0.03 microg g(-1) creatinine in 1993/1994 and 6.40 vs. 0.01 microg g(-1) creatinine in 1995, respectively). Urine uranium concentrations measured in 1995 were consistent with those measured in 1994/1993, with a correlation coefficient of 0.9. Spot urine measurements of uranium excretion were also well correlated with 24-h urine collections (r = 0.95), indicating that spot urine samples can be reliably used to monitor depleted uranium excretion in the surveillance program for this cohort of soldiers. The presence of uranium in the urine can be used to determine the rate at which embedded depleted uranium fragments are releasing biologically active uranium ions. No evidence of a relationship between urine uranium excretion and renal function could be demonstrated. Evaluation of this cohort continues.

Amputation, Surgical↗
PubMed1999

Severe skin reactions from interventional fluoroscopy: case report and review of the literature.

Some patients with certain preexisting health conditions may be at elevated risk for unusually intense radiation-induced skin reactions and late tissue damage from high-dose interventional procedures. The authors present a case report of a patient with mixed connective tissue disease and non-insulin-dependent diabetes mellitus who developed an unusual complication after placement of a transjugular intrahepatic portosystemic shunt. On the basis of a review of the literature, the following experiences may help identify patients at increased risk: previous high-dose procedures, connective tissue disease, diabetes mellitus, and homozygosity for ataxia telangiectasia.

Diabetes Mellitus, Type 2↗
PubMed1999

Muscle quality. II. Effects Of strength training in 65- to 75-yr-old men and women.

To determine the effects of strength training (ST) on muscle quality (MQ, strength/muscle volume of the trained muscle group), 12 healthy older men (69 +/- 3 yr, range 65-75 yr) and 11 healthy older women (68 +/- 3 yr, range 65-73 yr) were studied before and after a unilateral leg ST program. After a warm-up set, four sets of heavy-resistance knee extensor ST exercise were performed 3 days/wk for 9 wk on the Keiser K-300 leg extension machine. The men exhibited greater absolute increases in the knee extension one-repetition maximum (1-RM) strength test (75 +/- 2 and 94 +/- 3 kg before and after training, respectively) and in quadriceps muscle volume measured by magnetic resonance imaging (1,753 +/- 44 and 1, 955 +/- 43 cm3) than the women (42 +/- 2 and 55 +/- 3 kg for the 1-RM test and 1,125 +/- 53 vs. 1,261 +/- 65 cm3 for quadriceps muscle volume before and after training, respectively, in women; both P < 0.05). However, percent increases were similar for men and women in the 1-RM test (27 and 29% for men and women, respectively), muscle volume (12% for both), and MQ (14 and 16% for men and women, respectively). Significant increases in MQ were observed in both groups in the trained leg (both P < 0.05) and in the 1-RM test for the untrained leg (both P < 0.05), but no significant differences were observed between groups, suggesting neuromuscular adaptations in both gender groups. Thus, although older men appear to have a greater capacity for absolute strength and muscle mass gains than older women in response to ST, the relative contribution of neuromuscular and hypertrophic factors to the increase in strength appears to be similar between genders.

Aged↗
PubMed1999

Intracranial internal carotid artery angioplasty: technique with clinical and radiographic results and follow-up.

OBJECTIVE: Our objective is to describe the use of percutaneous transluminal angioplasty in eight patients with symptomatic high-grade atherosclerotic intracranial internal carotid artery stenoses. We describe our technique for performing the procedure and clinical and radiographic follow-up for an average of 53 months to determine the long-term results. CONCLUSION: Percutaneous transluminal angioplasty was shown to be an efficacious treatment for symptomatic intracranial internal carotid artery atherosclerotic disease in our group of patients.

Aged↗
PubMed1998

Economic and clinical impact of filmless operation in a multifacility environment.

The transition from conventional film-based to filmless operation at the Baltimore Veterans Affairs (VA) Medical Center has resulted in a large number of clinical and economic benefits. The integration of the Department of VA hospitals in Maryland into the VA Maryland Health Care System has resulted in the opportunity to establish a "virtual" radiology and nuclear medicine department. This integrated department is based on a wide area network in which outlying medical centers use a central hospital information system/radiology information system (HIS/RIS) and a central commercial picture archiving and communication system (PACS), as well as a VA-developed image management and communication system. The creation of this virtual radiology/nuclear medicine department has resulted in additional savings and improvements in clinical care. The benefits of the PACS are made possible, to a large extent, by the high level of integration of the PACS and medical modalities with the hospital information and transcription systems. Our experience suggests that it is absolutely essential to integrate the PACS into the patient's electronic medical record to maximize efficiency and clinical effectiveness of the system.

Computer Communication Networks↗
PubMed1998

Impact of filmless imaging on the frequency of clinician review of radiology images.

The purpose of this study was to determine the impact of filmless imaging on the frequency with which physicians access radiology images and to assess clinician perception of image accessibility using a hospital-wide Picture Archival and Communication System (PACS). Quantitative data were collected at the Baltimore VA Medical Center (BVAMC), prior to and after conversion to filmless imaging, to determine the frequency with which clinicians access radiology images. Survey data were also collected to assess physician preferences of image accessibility, time management, and overall patient care when comparing filmless and film-based modes of operation. In general, there was a significant increase in the average number of radiology images reviewed by clinicians throughout the hospital. However, the one are in the hospital where this trend was not observed was in the intensive care unit (ICU), where the frequency of image assess was similar between film and filmless operations. Ninety-eight percent of clinicians surveyed reported improved accessibility of images in a filmless environment resulting in improved time management. The mean clinician estimate of time saved due to the use of PACS was 44 minutes. The study documented a combination of clinician perception of improved accessibility and substantial time savings with the use of a hospital-wide PACS, which was supported by objective measurements. The increased frequency of image review by clinicians and rapid image access should provide a further impetus to radiologists to decrease report turnaround time to provided "added value" for patient care.

Baltimore↗
PubMed1998

Recommendations for image prefetch or film digitization strategy based on an analysis of an historic radiology image database.

Picture archiving and communications systems (PACS) utilize short- and long-term storage to provide both rapid retrieval and large storage capacity. Owing to the practical limitations imposed on the size of the much faster short-term storage, it is important to use an effective algorithm in the retrieval of comparison images from long to short-term storage. A strategy must be used to maximize the likelihood that the relevant historic images have been previously retrieved into short-term memory. Data were collected with a database consisting of 754 consecutive examinations and 7,723 associated historic studies. The most frequent number of previous examinations was zero (11% of patients). In 45% of cases, no previous matching examinations had been performed. Two basic strategies of image retrieval were evaluated. The first algorithm retrieved the last n studies in chronological order. The second strategy tested was retrieval based on a defined interval of time. This strategy was found to be less efficient. By using the former strategy, a 91% success rate (defined as successful retrieval of the previous matching exam) was achieved with retrieval of only 30% of the prior exams. The second approach required retrieval of 70% of the prior exams to achieve a 90% success rate for the previous matching exam. However, the data from this latter strategy suggest that examinations are often ordered in clusters. Thus, there was found to be a 72% likelihood that a previous matching exam, if present, would available on a PACS after only 1 week of operation, and an 80% chance after only 1 month of operation. The data therefore suggest that digitization of film in a new PACS environment might not be necessary owing to the relatively short period of time required to populate the database with historical studies.

Algorithms↗
PubMed1998

Vena caval occlusion after bird's nest filter placement.

BACKGROUND: Inferior vena caval thrombosis as a result of intracaval barrier devices occurs in 6.5% of patients with Greenfield filters. The incidence is less well defined in patients in whom bird's nest filters have been placed. We reviewed our experience with bird's nest filters to determine the incidence of filter-induced caval thrombosis. METHODS: The records of 140 patients with bird's nest filters were reviewed, living patients were interviewed, and the inferior vena cava examined in 37 patients by duplex scanning. RESULTS: Ninety-three patients were available for evaluation. Five of these patients were found to have caval thrombosis by duplex scanning and 2 had clinical symptoms and signs compatible with caval thrombosis. The majority of these patients were on anticoagulants at the time of filter thrombosis. CONCLUSION: The incidence of filter-induced vena caval thrombosis in patients with bird's nest filters (7%) is comparable with that of Greenfield filters. Because of the catastrophic manifestations of this complication and the increasing application of vena caval filters, the role of these filters in the treatment of thrombotic disease needs further critical evaluation.

Adolescent↗