OBJECTIVE: The purpose of this study was to compare observer performance in interpreting high-quality, digitally acquired computed radiographs of the chest displayed on either laser-printed radiographs or a workstation with observer performance in interpreting conventional chest radiographs. SUBJECTS AND METHODS: We performed a receiver-operating-characteristic study in which the presence or absence of five abnormalities was determined by nine experienced radiologists on 310 posteroanterior radiographs of the chest displayed in three forms: conventional radiographs, laser-printed films of digital radiographs, and digital radiographs on a high-resolution workstation. RESULTS: The results of our study suggest that observer performance with laser-printed films of digital radiographs obtained with high-resolution (4K x 5K), high-contrast sensitivity (12 bits) and appropriate exposure is comparable to observer performance with conventional radiographs. Observer performance with digital radiographs displayed on the workstation was found to be significantly lower for abnormalities that contained high-frequency and low-contrast information (e.g., interstitial disease and pneumothorax). CONCLUSION: Computed radiography technology can produce image quality that is adequate for interpreting posteroanterior radiographs of the chest. Observer performance is not as good when radiographs displayed on workstations are used to diagnose specific abnormalities.

Humans↗

PubMed1993

Budd-Chiari syndrome: imaging with pathologic correlation.

We retrospectively evaluated 21 patients with Budd-Chiari syndrome who underwent liver transplant. The pathological findings were correlated with imaging studies that included computed tomography (CT) in all cases, sonography in 20, and magnetic resonance (MR) in 15. Pathological features of Budd-Chiari syndrome in subacute or chronic form, such as parenchymal fibrosis, hemorrhage, and congestion, were found in all resected livers. These occurred usually in conjunction with restricted hepatic veins due to thrombosis or fibrosis with partially recanalized lumen. The status of hepatic veins was correctly assessed and correlated with pathology in 13 of 20 patients who had sonograms, in 12 of 15 patients who had MR, and in nine of 18 patients with contrast-enhanced CT scans. Patency of the inferior vena cava was well seen by all three modalities; parenchymal abnormalities were best visible on CT (19 of 21), while ascites, caudate lobe enlargement and collateral vessels were best detected with MR or CT. We conclude that each imaging modality offers certain values and limitations in the assessment of vascular or parenchymal findings in Budd-Chiari syndrome.

Adolescent↗

PubMed1993

Managed competition: implications for radiology.

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Academic Medical Centers↗

PubMed1992

Clinicians' access to diagnostic imaging information at an academic center: perceived impact on patient management.

We studied the efficiency with which clinicians were able to obtain the results of radiologic studies during visits to the radiology department in an effort to determine how often delays occurred and, if so, how they were perceived to have influenced patient care. We monitored 322 physician's visits to four locations within the radiology department in search of imaging information or consultative services. The average duration of these visits was 6.2 min (range, 38 sec-55 min). Two hundred forty-three visits (75%) were completed successfully, and 10 additional visits were for consultation purposes only. In 43% of the 69 unsuccessful visits, physicians indicated that lack of access to imaging information would definitely (38%) or possibly (6%) result in delays in diagnosis and/or therapy. In 17% of the unsuccessful visits, physicians indicated that the inability to access imaging information would definitely (13%) or possibly (4%) extend the patient's length of stay in the hospital. Our study suggests that better access to imaging information may prevent delays in patient management decisions, thereby substantially reducing costs and potentially improving patient care.

Hospitals, University↗

PubMed1991

Primary CT diagnosis of abdominal masses in a PACS environment.

Whether the display medium--film versus cathode ray tube (CRT)--affects observer performance during interpretation of computed tomographic (CT) images is an important research issue in these times of implementation and growth of picture archiving and communications systems in radiology. The authors performed a multiobserver receiver operating characteristic (ROC) study to determine the performance of radiologists who read abdominal CT studies displayed on film, as well as on a high-resolution workstation (video monitor) that made use of three different display modes. A total of 166 examinations were evaluated by eight radiologists, who recorded their ordinal confidence ratings of the demonstration of presence or absence of abdominal masses. ROC analysis showed small differences in the confidence ratings assigned by individual readers for the detection and interpretation tasks. Results for the group as a whole showed no significant reduction or improvement in observer performance when ratings for any one of the workstation display modes were analyzed. The results of this study demonstrate that current CRT display technology is adequate for enabling the primary detection of abdominal masses with CT examinations.

Abdominal Neoplasms↗

PubMed1991

Visual acuity testing of radiologists--is it time?

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Adult↗

PubMed1990

Effect of observer instruction on ROC study of chest images.

Receiver-operating characteristic (ROC) analysis has been used in many medical imaging applications during the past decade. In order to ensure that reader-confidence ratings are analyzable (well distributed to meet convergence requirements of curve-fitting algorithms) and meaningful (limit extrapolation of the data), many investigators train readers specifically for this purpose. No experimental data are available concerning the possible effects of such training on the results of ROC studies. We performed a multi-observer, multi-disease study in which 300 chest images were rated by four radiologists before and after they were trained to provide well-distributed confidence ratings. The results indicate that for our data set, reader and disease-specific accuracy was not significantly affected by the training process for interstitial disease and pneumothoraces. However, the accuracy of two readers was significantly affected for the detection of nodules (P less than 0.05), and the overall accuracy of one reader was significantly affected for the classification of normal versus abnormal images (P less than 0.01). Thus, in spite of the difficulties associated with the performance of ROC studies in a free-reading environment, one should carefully consider the possible effects of any intervention on the results prior to conducting ROC studies.

Humans↗

PubMed1990

Comparison of measured and perceived time values for radiologists' work: impact on relative value scales.

The authors compared the actual time required by radiologists to perform and/or interpret common diagnostic radiologic examinations with the times the same radiologists perceived were necessary (as determined with a survey) to perform and/or interpret those same examinations. Average measured times ranged from 1.7 minutes for radiologic examinations of extremities to 113.2 minutes for interventional procedures. Average survey times ranged from 3.2 minutes for examinations of extremities to 84.4 minutes for cerebral angiography. The mean difference between measured and survey times for all examinations was 48.6%. Relative value scales were developed based on measured and survey times, with the upper gastrointestinal examination assigned the base unit of 100. The difference between the measured-time and survey-time relative value scales was 98% on average for the 16 examinations compared. The study suggests that there is a need for actual measurement of at least the time component of physician work if resource-based relative value scales are to be used as the basis for physician compensation.

Academic Medical Centers↗

PubMed1990