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S E Seltzer

Publications and source records attributed to S E Seltzer.

At least 19 recordsLinked to original sources
PubMed2000

Modality interfacing: the impact of a relay station.

We evaluated the effect of a deploying a relay station on demographic discrepancies, image segmentation for routing, quality control (QC), and technologist workflow in a distributed architecture type picture archiving and communication system (PACS) environment. A currently existing PACS environment for computed tomography (CT) was evaluated before and after the implementation of a relay station for demographic error-rate and correct study routing to the workstations. Assessment of the technologists' perceptions with respect to numerous workflow factors was performed with a questionnaire. Statistical analysis was performed using a chi-square test. The demographic error rate for CT examinations was nearly abolished with relay station deployment (14.0% pre-Relay v 0.55% post-Relay, P < .001, chi2). The technologists' perception was favorable, with a substantial majority indicating that a positive impact is made on correcting demographic errors (90%), facilitating QC (67%), and ensuring proper routing (77%). A majority also felt the user interface was intuitive (93.3%) and preferred relay (90%) over film handling but that training should be provided both by didactic sessions and "hands on" time with a trainer. The times to perform tasks were favorable for the relay station (1 to 5 minutes) versus film production and handling (2 to 15 minutes). In conclusion, the relay station prospectively eliminates demographic errors, effectively segments images from the same study routing them to different workstations, and can be seamlessly integrated into the technologists' current workflow. This can be scalable and a lower cost solution as opposed to deploying dedicated PACS QC workstations.

Academic Medical Centers↗
PubMed2000

Perceived features reported as nodules: interpretation of spiral chest CT scans.

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate nontarget locations identified in a study of lung nodule detection with spiral computed tomographic (CT) scans that compared cine and film presentations. MATERIALS AND METHODS: In a previous study of lung nodule detection, eight observers were asked to identify 10 nodule locations in each of five CT scans containing eight simulated nodules. In the current study, each nontarget location that was reported more than once in the previous study was inspected with a stack-mode display in both cine and static modes. The nontarget locations were evaluated for probable identity, shape, and distance from the peripheral lung surface. RESULTS: Fifty-two nontarget locations included clinically undetected pulmonary nodules (n = 12), lymph nodes (n = 2), unclassifiable structures (n = 2), pleural scars (n = 8), and vascular structures (n = 28). Five nontarget locations contained vessels with complex courses apparent only with cine mode. As a group, nontarget locations were significantly closer to the periphery than would be expected by chance (for all locations, P < .0001; for locations not touching the pleural surface, P = .013). CONCLUSION: The lower reporting threshold caused by the observer instructions to find 10 targets resulted in increased reporting of structure with a nodular appearance. The locations of these reports in the lung periphery can be attributed to the relationship between frequent disease and a nearly featureless background in the lung periphery.

Adult↗
PubMed1998

Percutaneous abdominal biopsy: cost-identification analysis.

PURPOSE: To determine the difference in cost to providers of percutaneous abdominal biopsy as the first strategy versus surgical biopsy. MATERIALS AND METHODS: Cost of tissue diagnosis determination with percutaneous biopsy as the first strategy in 439 patients with an abdominal mass was estimated. Costs included direct hospital costs and professional costs of initial and repeat biopsy, follow-up imaging and clinic visits, surgical biopsy (when needed), and treatment of complications. The sum of these costs was compared with the estimated cost had the same patients undergone surgical biopsy instead, with no complications or need for follow-up or repeat biopsy. RESULTS: The total estimated cost of percutaneous biopsy as the first strategy ($543,245) was less than the cost had surgical biopsy been used alone ($1,919,867). The average per patient direct hospital cost of percutaneous biopsy ($800) was lower than that of surgical biopsy ($3,419). The average per patient professional cost of percutaneous biopsy ($438) was also lower than that of surgical biopsy ($955). Savings averaged $3,136 per patient, or $1,376,622 for the study period. CONCLUSION: Substantial health care cost savings may result by using a diagnostic algorithm in which percutaneous biopsy is the first strategy for establishment of a diagnosis in patients suspected of having abdominal malignancy.

Abdominal Neoplasms↗
PubMed1998

Influence of CT image size and format on accuracy of lung nodule detection.

PURPOSE: To evaluate the effect of reducing image size on observers' ability to detect lung nodules on computed tomographic (CT) scans. MATERIALS AND METHODS: Stimuli were 80 single sections from 13 normal chest CT studies. On half of the images, 3-5-mm-diameter nodules were superimposed electronically at random locations. Four observers viewed images in six formats and sizes that ranged from 6 on 1 (133 x 133 mm) to 80 on 1 (40 x 40 mm). The images were viewed at a fixed distance of 55 cm and at an unrestricted, variable distance. RESULTS: With the fixed viewing distance, nodule detection decreased with smaller image sizes. The area under the receiver operating characteristic curve (Az) decreased from 0.857 for the 6-on-1 format to 0.671 for the 80-on-1 format (P = .0001). With a variable viewing distance, Az decreased from 0.884 to 0.834 across all formats (difference not statistically significant). However, there was a significant drop in performance with the smallest images (P < .05). Overall, Az for the fixed and variable viewing distances was significantly different (P < .001). CONCLUSION: Reducing image size leads to decreased lung nodule detection on CT scans viewed at a fixed distance; however, the observer can compensate for the smaller image by adjusting the viewing distance.

Humans↗
PubMed1998

Can academic radiology departments become more efficient and cost less?

PURPOSE: To determine how successful two large academic radiology departments have been in responding to market-driven pressures to reduce costs and improve productivity by downsizing their technical and support staffs while maintaining or increasing volume. MATERIALS AND METHODS: A longitudinal study was performed in which benchmarking techniques were used to assess the changes in cost and productivity of the two departments for 5 years (fiscal years 1992-1996). Cost per relative value unit and relative value units per full-time equivalent employee were tracked. RESULTS: Substantial cost reduction and productivity enhancement were realized as linear improvements in two key metrics, namely, cost per relative value unit (decline of 19.0% [decline of $7.60 on a base year cost of $40.00] to 28.8% [$12.18 of $42.21]; P < or = .001) and relative value unit per full-time equivalent employee (increase of 46.0% [increase of 759.55 units over a base year productivity of 1,651.45 units] to 55.8% [968.28 of 1,733.97 units]; P < .001), during the 5 years of study. CONCLUSION: Academic radiology departments have proved that they can "do more with less" over a sustained period.

Academic Medical Centers↗
PubMed1998

Trends in the use of radiology with inpatients: what has changed in a decade?

OBJECTIVE: Our goal was to evaluate trends in the use of radiology with inpatients in the 10-year period of 1984-1993. MATERIALS AND METHODS: We retrospectively reviewed administrative data from a 751-bed, tertiary care hospital between October 1, 1983, and September 30, 1993 (Fiscal years 1984-1993). We coded each study by imaging technique: CT, MR imaging, sonography, nuclear medicine, or conventional studies (plain films and fluoroscopy). Echocardiography, cardiac catheterization, and angioplasty procedures were omitted. The number of admissions per year was adjusted for severity of disease (case-mix-adjusted admission [CMA]). We used relative value units to evaluate workload changes during the study period. We assessed significance of trends using linear regression analysis. RESULTS: The total number of imaging studies per CMA decreased during the study period (p = .0001). This was due to a decrease in the number of conventional studies (p = .0001) and sonograms per CMA (p = .02), despite significant increases in the numbers of CT (p = .005) and MR imaging (p = .0001) studies per CMA. No significant change existed in the number of nuclear medicine studies per CMA (p = .11). The global, professional, and technical relative value units per CMA rose during the latter half of the study. CONCLUSION: The overall number of imaging studies per CMA decreased during the decade, despite a significant rise in the use of CT and MR imaging, suggesting that these new imaging techniques are replacing older ones. To control further increases in overall imaging costs, priority should be placed on understanding the patterns of use for CT and MR imaging techniques and curbing their inappropriate use.

Adult↗
PubMed1998

Web-based digital radiology teaching file: facilitating case input at time of interpretation.

OBJECTIVE: Our goal was to develop a software system that allows easy and rapid input of digital radiology images and text reports, at the time of interpretation, into an easily searchable electronic teaching file database using the Internet and the World-Wide Web protocols, servers, and browsers. CONCLUSION: Using the Internet, the World-Wide Web, and our software system, we can rapidly input digital radiology images and associated text reports into an easily searchable database accessed by privileged users. This inexpensive and simple method for building a digital teaching file database allows cross-platform access for users who have a Web browser.

Computer Communication Networks↗
PubMed1998

Negative predictive value of imaging-guided abdominal biopsy results: cytologic classification and implications for patient management.

OBJECTIVE: Our purpose was to assess the negative predictive value of imaging-guided abdominal biopsy results and correlate it with cytology classification, lesion size, needle gauge, and cancer history. MATERIALS AND METHODS: A retrospective study was performed of 100 patients with proven diagnoses who had undergone imaging-guided abdominal biopsies showing no cells that were malignant or suspicious for malignancy. Specimens were classified as normal or benign, nondiagnostic, or atypical. Negative predictive value was calculated for each cytologic category, lesion size, needle gauge, and cancer history. Logistic regression analysis was performed to allow us to identify predictors of false-negative results. RESULTS: Overall negative predictive value was 67%. Other negative predictive values were normal or benign result, 78%; nondiagnostic result, 66%; and atypical result, 29%. Negative predictive value was greater when the lesion was large (> or =3 cm) (p = .031). Logistic regression analysis allowed us to predict a 9.3% chance of a false-negative result for a specimen of normal or benign cytology that was taken from a large lesion in a patient with no cancer history but an 87% chance of a false-negative when a specimen of atypical cytology was taken from a small (<3 cm) lesion in a patient with a cancer history. CONCLUSION: Imaging-guided abdominal biopsy specimens containing atypical cells should be viewed with caution. In patients without cancer, if a lesion is large and the specimen contains normal target organ or benign cells, the likelihood of a false-negative result may be low enough that imaging surveillance at appropriate intervals may be sufficient.

Abdominal Neoplasms↗
PubMed1997

Influence of visual distractors on detectability of liver nodules on contrast-enhanced spiral computed tomography scans.

RATIONALE AND OBJECTIVES: The authors evaluated the ability of observers to identify simulated nodules placed electronically on normal contrast material-enhanced computed tomography (CT) scans of the liver to assess the effect of nodule size and polarity on detection and localization. METHODS: Seven readers evaluated two sets of CT scans that contained 80 stimuli each. The simulated nodules were either darker or brighter than the contrast-enhanced liver and were 5.6-8.0 mm in diameter. Readers were asked to find the most suspicious-looking nodule on each section and rate the likelihood that the chosen location actually contained a nodule. RESULTS: The fraction of nodules found by each observer was substantially greater for dark nodules than for bright ones (0.679 +/- 0.03 vs 0.345 +/- 0.045, respectively [mean +/- standard error]). This difference was consistent for all nodule sizes. Additional analyses (including receiver operating characteristic curves of conditional responses) suggested that the presence of bright blood vessels distracted the readers and decreased their ability to find bright nodules. CONCLUSION: Normal vascular structures on contrast-enhanced CT scans of the liver impair an observer's ability to detect bright liver nodules.

Humans↗
PubMed1997

Achievement of substantial cost reduction through joint purchasing by the radiology departments of a large vertically integrated health care system.

RATIONALE AND OBJECTIVES: The authors sought to lower costs by coordinating the purchase of equipment, supplies, and services in the radiology departments of a vertically integrated health system formed by the merger of two of the largest academic medical centers in New England. METHODS: The radiology departments at Massachusetts General Hospital and Brigham & Women's Hospital formed a cost-reduction task force to explore opportunities to jointly decrease costs. Data from the operating budgets of both institutions were collected and analyzed to find specific items within the budgets that could yield substantial cost savings. RESULTS: The project's first phase yielded over $810,000 in reduced costs from a system-wide annual budget of only $7 million for film and contrast material. Ongoing additional projects suggest that longer term contracts that contain steeper discounts with a decreased number of vendors will result in further decreases in the cost of materials and supplies. CONCLUSION: Coordination of purchasing by the radiology members of an integrated delivery system can yield substantial savings.

Cost Control↗
PubMed1997

Staging prostate cancer with MR imaging: a combined radiologist-computer system.

PURPOSE: To test the accuracy of a combined radiologist-computer system in the diagnosis with magnetic resonance (MR) imaging of cancer of the prostate gland. MATERIALS AND METHODS: The combined system was developed and tested by four specialists in prostate MR imaging and five radiologists expert in body MR imaging. Each group read MR images obtained in 100 proved cases of prostate cancer. The images were obtained from two sources, and all were obtained with an endorectal surface coil. Prostate MR specialists ranked imaging features of cases to develop a checklist for image interpretation. Features with greatest diagnostic value were incorporated in the combined system. Accuracy measures were derived from the area index of the receiver operating characteristic curve for the combined system and compared with those of radiologists working alone. RESULTS: Body MR radiologists had a mean baseline accuracy of 0.67; mean accuracy of their combined system was 0.80. The prostate MR specialists, when they rated the features in each case, had a mean accuracy of 0.81; the accuracy of their combined system was 0.87. CONCLUSIONS: A combined radiologist-computer system substantially improved accuracy of body MR radiologists in the diagnosis of prostate cancer. High levels of accuracy were also achieved by the system with prostate MR specialists.

Diagnosis, Computer-Assisted↗
PubMed1997

Prostate cancer: relative effects of demographic, clinical, histologic, and MR imaging variables on the accuracy of staging.

PURPOSE: To determine the effects on the accuracy of staging prostate gland cancer of diagnostic prediction rules based on demographic, clinical, histologic, and magnetic resonance (MR) image variables. MATERIALS AND METHODS: A total of 200 cases from four medical centers were evaluated by nine radiologists experienced in MR imaging. The accuracies of the four diagnostic variables (age, prostate specific antigen level, Gleason tumor grade, and MR imaging findings) were measured, both singly and combined in a particular sequence, by calculating the area index of the receiver operating characteristic curve. RESULTS: The accuracy of staging with single variables (age, 0.58; prostate specific antigen level, 0.74; Gleason grade 0.73, MR image findings, 0.74) increased as the variables were optimally merged. The first two variables combined to yield an accuracy of 0.74; the first three combined to yield an accuracy of 0.81; and all four variables resulted in an accuracy of 0.86. In a clinically important subset of 69 cases for which antigen level and Gleason grade together were inconclusive for the purposes of staging, the addition of MR imaging findings resulted in an increase in accuracy from 0.55 to 0.73. CONCLUSION: Optimal merging of diagnostic test results yields an improvement in the accuracy of prostate cancer staging.

Age Factors↗
PubMed1997

Expediting the turnaround of radiology reports in a teaching hospital setting.

OBJECTIVE: The purpose of this study was to determine whether total quality management (TQM) techniques that had proved successful in a pilot study in one departmental section of a teaching hospital could be generalized for use by the entire radiology department. MATERIALS AND METHODS: Each departmental section developed interventions to improve its report turnaround time. These interventions were tailored to practice style and habits of each section. Commonly used interventions included electronic signature from the radiologist's home, a report-signing buddy system, elimination of a trainee signature requirement, accelerated transcription, structured reports, faster film delivery to reading desks, and training about the importance of radiology reports for clinical decision making. Specialized programs included computerized form-driven reporting and reports generated directly by computer voice recognition of radiologists' dictation. Our radiology information system provided data on each step in the reporting process. RESULTS: The TQM approach produced significant improvements in departmental total report turnaround time (-55%; p = .001), transcription time (-80%; p = .003), and signature time (-68%; p = .0004). Each section achieved significant gains. The sonography section initiated a computerized, form-driven reporting system and outperformed the rest of the department. CONCLUSIONS: TQM techniques can be expanded and generalized for department-wide projects in teaching hospitals.

Communication↗
PubMed1996

Small (< or = 3 cm) hyperechoic renal masses: comparison of helical and convention CT for diagnosing angiomyolipoma.

OBJECTIVE: Because hyperechoic renal masses may represent angiomyolipomas or small renal cancers, CT is often used to reveal the fatty component, which allows diagnosis of angiomyolipoma in most cases. Because conventional CT can fail to reveal fat in angiomyolipomas 3 cm or smaller, we conducted a study to determine whether helical CT would improve our detection of fat and allow more of these masses to be diagnosed as angiomyolipomas. SUBJECTS AND METHODS: We used helical and conventional CT to examine 20 masses (5-29 mm in diameter) in 17 patients who had a small hyperechoic mass detected sonographically. Densitometry was performed by three readers and the mean attenuation values were compared. RESULTS: Of the 20 masses, we diagnosed angiomyolipoma in 16 masses using helical CT and in 14 masses using conventional CT. In 11 masses, we found the measured attenuation values to be more negative on helical CT scans than on conventional CT scans. In five masses, we found the opposite to be true. In the remaining four masses, we were unable to diagnose angiomyolipoma. Of the masses that we diagnosed as angiomyolipoma, the mean attenuation value when examined with helical CT (-44 H) was more negative than with conventional CT (-35 H) but not significantly so (p = .058). However, in the subset of patients with masses that were 2 cm or less in diameter (n = 14), the mean attenuation values on helical CT were significantly lower than on conventional CT (-40 H versus -30 H, p < .05). Likewise, for masses with attenuation values that differed by more than 6 H (n = 8), when imaged by the two techniques we again found that mean attenuation values on helical CT were significantly lower (-43 H versus -24 H, p < .05). CONCLUSION: Helical CT revealed angiomyolipoma across all cases as well as conventional CT did. Also, helical CT was more sensitive in revealing fat in masses less than 2 cm in diameter and in masses in which the attenuations of the two CT techniques differed by a significant amount. We preferred helical CT over conventional CT when examining hyperechoic masses for the purpose of diagnosing angiomyolipoma.

Adult↗
PubMed1995

Spiral computed tomography of the liver: contrast agent pharmacokinetics and the potential for improved hepatic enhancement.

RATIONALE AND OBJECTIVES: We conducted a prospective study of 131 patients to evaluate the contrast agent dose-response relationship for liver spiral computed tomography (CT) and to test the hypothesis that spiral CT scanning provides greater enhancement than does dynamic CT scanning. METHODS: Patients were assigned to one of two control groups (dynamic CT) or to one of five experimental groups (spiral CT). Dynamic CT patients received 150 ml and spiral CT patients received either 75, 100, or 150 ml of diatrizoate meglumine. All groups had a monophasic injection rate of 2.5 ml/sec. Hepatic enhancement was compared among experimental and control groups. RESULTS: In the experimental groups, there was a linear dose-response relationship (p < .0001) among the enhancements achieved for the three dosages. The enhancement of the last slice of liver for the spiral CT versus dynamic CT groups receiving 150 ml was significantly greater (p = .002). Peak, first liver slice, and average liver enhancement values were higher with spiral CT scanning, but the difference was not statistically significant (power > .55). CONCLUSION: Using uniphasic injection rates and identical doses of contrast agent, spiral CT scanning has the advantage of improved enhancement of the last part of the liver to be imaged.

Adult↗