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Biomedical subjects

K S Berbaum

Publications and source records attributed to K S Berbaum.

At least 55 records · Page 3Linked to original sources

Radiologic interpretation by family physicians in an office practice setting.

BACKGROUND: Radiology is an integral part of the office practice of many family physicians. Nevertheless, data are sparse on the performance of family physicians in this endeavor. This study investigated the performance of family physicians at interpreting radiographs ordered in a free-standing family practice office. METHODS: A consecutive series of radiographic studies performed at a family practice office during a 3-year period was surveyed. All radiographic studies included in this analysis (N = 1674) were separately interpreted by the family physician ordering the study and an overreading radiologist. If the interpretations agreed, the studies were accepted as having been correctly interpreted. Cases in which the interpretations disagreed were reexamined. RESULTS: Family physicians correctly interpreted 92.4% of the radiographic studies (95% confidence interval, 91.0 to 93.6). Their accuracy with extremity films (96.0%) was significantly higher than their accuracy with chest films (89.3%, P < .001). Family physicians were more likely to correctly interpret normal films (95.2%) than abnormal ones (85.9%, P < .001). Thirty-five percent of the cases in which there were differences between family physician and radiologist interpretations were correctly interpreted by family physicians. CONCLUSIONS: Family physicians showed a high degree of accuracy in radiologic interpretation in an office setting. Chest films were inherently more difficult to interpret than extremity films. Because correct interpretation depends on body part examined and the prevalence of disease, the performance of family physicians will probably vary in different practice settings.

Ambulatory Care↗

Scintigraphic evaluation of small bowel transit in healthy subjects: inter- and intrasubject variability.

OBJECTIVES: This study was performed to evaluate inter- and intrasubject variability of small bowel transit time and the effect of age and sex on transit in the small bowel. METHODS: Ten young subjects (five females) and nine elderly subjects (four females) were studied. Small bowel transit time was assessed by scintigraphic method using 99mtechnetium-sulfur colloid-labeled eggs. To evaluate intrasubject variability, 10 subjects underwent a second study on a later occasion. RESULTS: Mean small bowel transit time was 220.9 +/- 49 min with a range of 131 to 322 min, with no significant difference between the young and elderly groups or between sexes. There was a good intraobserver and interobserver reproducibility within the same test (r = 0.92 and r = 0.85, respectively). There was a significant biological variability between the first and the second studies, which was true whether the studies were processed independently (r = 0.43) or whether identical regions of interest were applied (r = 0.50). CONCLUSION: The normal range of small bowel transit time is wide in normal subjects; and there is a significant intrasubject biological variability for small bowel transit time. These findings should be kept in mind when using scintigraphic techniques for assessment of patients with motility disorders or when using the test repeatedly in the same subject in the evaluation of therapeutic measures. The results do not seem to be affected by age or sex.

Adult↗

Influence of clinical history on perception of abnormalities in pediatric radiographs.

RATIONALE AND OBJECTIVES: We tested whether having clinical information would improve perception or simply decision making. METHODS: Sixty-four pediatric chest and abdominal radiographs, half of which had abnormalities, were presented to nine radiologists under one of two conditions. In one condition, history consistent with abnormalities actually present for positive cases was provided for positive and matched negative cases before inspection. In a second condition, this information was provided only after inspection was completed and the radiograph was no longer available. Because detailed visual memory is short-lived, the image information was no longer available when the history was provided after inspection. A control condition measured detection without history. RESULTS: Detection was significantly better with history provided before inspection. Detection did not differ for history provided after inspection and inspection without history. CONCLUSION: The only difference between conditions with history was in whether history influenced perception; history affected decision making in both conditions. Clinical history affected perception in interpreting radiographs, not simply decision making.

Adolescent↗

Satisfaction of search in the detection of plain-film abnormalities in abdominal contrast studies.

RATIONALE AND OBJECTIVES: Satisfaction of search (SOS) occurs when a lesion is "missed" after detecting another lesion in the same radiograph. The authors investigated the SOS effect in abdominal contrast studies. METHODS: The authors measured detection of 23 plain film abnormalities in 43 patients who had plain film and contrast examinations. Each plain-film and contrast study was examined independently by 10 radiologists in two sessions, with receiver operating characteristic (ROC) curve areas estimated with the computer program RSCORE-J (University of Iowa, Iowa City, IA) for each condition. RESULTS: Observers more often missed plain film abnormalities present on contrast studies but also made fewer false-positive (FP) responses. There was no change in ROC area, but decision criteria grew more conservative. CONCLUSIONS: The reduction of detecting plain-film abnormalities in contrast examinations differs from the SOS effect of other imaging studies. The reduction in true-positive (TP) and false-positive (FP) rates suggests that a different cause may underlie these misses.

Contrast Media↗

Reliability of standard foot radiographic measurements.

Fifty standing dorsoplantar and lateral foot radiographs were obtained on a consecutive series of patients seen in an orthopaedic foot and ankle clinic. These radiographs were duplicated, and eight common foot measurements were made on each pair by six experienced examiners. Measurements were made in two ways: first by a subjective visual assessment, and second by quantitative evaluation made according to strictly defined criteria. All measurements were made under controlled, ideal conditions with similar high quality goniometers. The results demonstrated overall greater reliability in the quantitative methods than the non-quantitative methods. For each of the quantitative techniques, a cumulated frequency distribution of differences between examiners was calculated. The approximate 95% bounds for these measures were: hallux-metatarsophalangeal angle = 6 degrees, first intermetatarsal angle = 4 degrees, metatarsophalangeal-5 angle = 11 degrees, fourth intermetatarsal angle = 4 degrees, AP talocalcaneal angle = 20 degrees, lateral talocalcaneal angle = 12 degrees, sesamoid station = 2 grades, and forefoot width = 5 mm. Physicians using these parameters to make decisions regarding patient care and clinical outcomes need to keep in mind these potential errors in making foot radiographic measurements.

Ankle↗

The influence of clinical history on visual search with single and multiple abnormalities.

RATIONALE AND OBJECTIVES: Facilitation of detection by clinical history generally has been found with a single abnormality per image but not with multiple abnormalities. Multiple abnormalities per image can occasion a "satisfaction-of-search" effect in which detection of one lesion is reduced in the presence of other distant lesions. Our experiment studied the combined effect of multiple abnormalities and clinical history on accuracy. METHODS: Detection of native lesions was measured 1) with histories suggestive of the native abnormality; 2) with these histories and added simulated pulmonary nodules; and 3) with the same added nodules and histories suggestive of metastatic disease. These conditions also were compared with those of a previous experiment that were similar but included no history. RESULTS: Detection was substantially improved for appropriately prompted abnormalities even in the presence of a pulmonary nodule. In fact, satisfaction of search was not found in the presence of an appropriate history. Detection of unprompted abnormalities was unchanged when prompts indicated other abnormalities actually present. Prompted abnormalities were detected earlier in search. CONCLUSIONS: History appears to direct perceptual resources to the prompted abnormalities, thereby alleviating satisfaction of search. The presence of nodules yielded a small but consistent reduction in total search time for searches involving false responses, suggesting that satisfaction of search may depend more on reduction in search time than had been indicated by previous research.

Diagnostic Errors↗

Comparison of oral cholecystography and ultrasonography for evaluating chronic cholecystitis using patient outcome as the reference standard.

RATIONALE AND OBJECTIVES: The authors compared oral cholecystography (OCG) with ultrasound (US) in the detection of chronic gallbladder disease using clinical outcome, rather than pathology results, as the reference standard. METHODS: The authors interviewed 269 patients who underwent either OCG, US, or both, for evaluation of chronic right upper quadrant abdominal pain. The authors considered patients who underwent cholecystectomy with improved symptoms 1 to 4 years after surgery to be reference-standard positive for gallbladder disease, and patients with objective evidence of an alternative diagnosis (eg, peptic ulcer disease), which improved with therapy as reference-standard negative. RESULTS: The sensitivity and specificity of OCG were 83% and 97%, respectively, and for US, 86% and 90%, respectively. CONCLUSIONS: OCG is comparable with US in evaluating of chronic gallbladder disease. In institutions where OCG is used for diagnosing chronic cholecystitis, it may be reasonable to continue using OCG.

Algorithms↗

Gadolinium-enhanced MRI of soft tissue masses.

The efficacy of gadopentetate dimeglumine (Gd-DTPA) enhanced magnetic resonance (MR) imaging in the diagnosis and differentiation of soft-tissue, neoplastic and non-neoplastic lesion has not been well established. Thirty patients with soft tissue masses (18 neoplastic and 12 non-neoplastic) were studied, using MR imaging with and without administration of Gd-DTPA. Gd-DTPA proved helpful in characterisation of several entities, including differentiation of solid mass from proteinaceous cyst, demonstration of tumour nodules within haemorrhagic or necrotic masses, and delineation of tumour adjacent to oedema. The use of Gd-DTPA may provide additional information for tissue specificity and, in complicated cases, Gd-DTPA may also provide essential information that cannot be obtained using other methods. We recommend the use of contrast enhanced MR as an adjunct to conventional MR imaging in the initial assessment of musculoskeletal soft tissue masses. However, T2-weighted images show better tissue contrast of the lesions, and are equal to contrast enhanced images in delineation of tumour margins. Non-contrast enhanced images are, therefore, probably adequate for the delineation of lesions for surgical planning when a diagnosis has already been made.

Connective Tissue Diseases↗

Evaluation of a digital workstation for interpreting neonatal examinations. A receiver operating characteristic study.

RATIONALE AND OBJECTIVES: The purpose of this study is to compare the diagnostic accuracy of interpreting clinical neonatal radiographs using a commercially available digital workstation versus conventional radiographic images. METHODS: The case sample consists of 100 chest or abdominal radiographs from the neonatal intensive care unit in which diagnosis was confirmed. Four radiologists served as observers. During two initial reading sessions, half of the studies were viewed on digital radiography monitors and the other half by plain film. Observers indicated whether each patient had normal or abnormal findings and their degree of confidence in this judgment. Six weeks later, observers viewed cases on the alternate presentation system. Two statistical analyses were performed: the data from each observer were treated as a separate experiment in the first analysis; the data from all observers were combined using a new method in the second analysis. RESULTS: No differences between areas under receiver operating characteristic (ROC) curves for viewing on the picture archiving and communication system (PACS) console and plain film were found for any observer (0.86 versus 0.86, 0.89 versus 0.86, 0.88 versus 0.85, 0.83 versus 0.82). CONCLUSIONS: The study suggests that for pediatric plain film images, video images offer diagnostic information comparable with that of conventional radiographs for neonatal examinations.

Evaluation Studies as Topic↗

Error in radiology: classification and lessons in 182 cases presented at a problem case conference.

The authors review and classify errors in 182 cases that were presented at problem case conferences between August 1986 and October 1990. Errors were classified by means of a system developed 20 years ago and by means of a system developed within the past several years. The authors found that sources of error have changed very little. Errors usually involved failure to consult old radiologic studies or reports, limitations in imaging technique, acquisition of inaccurate or incomplete clinical history, location of a lesion outside the area of interest on an image, lack of knowledge, failure to continue to search for abnormalities after the first abnormality was found, and failure to recognize a normal biologic variant. Errors included 126 perceptual errors (64 false-negative, 15 false-positive, and 47 misclassification errors) and 56 mishaps, including 38 complications and 18 communication errors. In seven cases nonperception errors occurred because established departmental routines were not followed, and in nine cases a new departmental routine was established after a complication occurred. Departmental policy exerts less effect on perception and interpretation errors.

Diagnostic Errors↗

Three-dimensional viewing of and dosimetric calculations in Au-198 implants of the prostate.

A three-dimensional system for dosimetric calculation of radiation from interstitial brachytherapeutic implants was developed and was compared with conventional dosimetry performed with a commercial two-dimensional system. Software programs written for this study enabled the authors to place radioactive sources in the correct reconstructed anatomic locations, compute the isodose distribution around these sources, and display the isodose curves in their correct relationship to anatomic structures. Eight radiation oncologists evaluated the usefulness of both systems. Verification studies in phantoms and in 20 patients with gold-198 implants in the prostate gland showed that the experimental system was very accurate in volume reconstruction, seed localization, isodose distribution, point-dose calculation, and computation of dose-volume histograms. Although the dose depictions in the two systems matched almost exactly, statistically significant differences existed in interpretation of the dosimetric data generated by both systems. For example, the oncologists consistently believed that the dose to the prostate was lower when the three-dimensional system was used (P less than or equal to .0001).

Brachytherapy↗

MR imaging of patellar tendinitis.

To identify magnetic resonance (MR) imaging characteristics of normal patellar tendons and those affected by tendinitis, the authors evaluated MR images obtained in 10 healthy volunteers, in 50 patients who underwent MR imaging for evaluation of knee structures other than the patellar tendon, in 11 patients with patellar tendinitis, and in two athletes with patellar tendon injuries. Normal tendons had uniformly low signal intensity on T1-, T2-, and proton-density-weighted images and displayed distinct margins, and the anteroposterior (AP) diameter slightly increased proximally to distally. It was concluded that the AP diameter of a normal tendon, in its proximal portion, should not exceed 7 mm. In patellar tendinitis, the tendon showed increased signal intensity on T1-, T2-, and proton-density-weighted images and increased AP diameter proximally. The margins of affected tendons were indistinct, especially posterior to the thickened segment. In all groups studied, women had thicker proximal tendons than did men.

Adult↗

Comparison of the efficacy of digital subtraction and film-screen angiography of the lower limb: prospective study in 50 patients.

We prospectively compared current digital subtraction angiography (DSA) with conventional film-screen angiography (FSA) of the lower limb for evaluation of areas of arterial stenosis and degree of arterial visualization. Fifty patients had both DSA and FSA of a single lower limb. Specific anatomic sites (examiner-selected sites) throughout the lower limb were marked on each film by an experienced angiographer (examiner). These sites consisted of the common femoral, superficial femoral, popliteal, anterior tibial, posterior tibial, peroneal, and dorsalis pedis arteries and bypass grafts, when present. The films were then reviewed blindly by two different experienced angiographers (observers). All sites were graded for the degree of arterial narrowing based on a standard scale (grade 1 = normal, grade 5 = occluded) that also included grading for nonvisualization (grade 6). Each observer also selected the most stenotic site in each anatomic area (observer-selected sites). The data were analyzed for the entire lower limb and at specific anatomic sites. DSA sites were judged to be slightly more narrowed (p less than .05) in the superficial femoral artery by both observers and in the common femoral artery, bypass graft, and overall by a single observer. No other significant differences were found in grade of stenosis or vessel visualization for examiner-selected sites. For observer-selected sites, observers agreed on the location of the most stenotic site 76% of the time for FSA and 69% of the time for DSA. No significant difference was found in grade of stenosis or vessel visualization for either observer for the entire lower limb or at specific anatomic sites. These findings were present when all sites chosen were considered and when there was agreement between sites chosen on FSA and DSA for each observer. In conclusion, optimal-quality FSA and DSA produced virtually equivalent results for angiography of the lower limb for both grade of stenosis/occlusion and vessel visualization.

Angiography↗

Use of a motion sickness history questionnaire for prediction of simulator sickness.

This research assessed the usefulness of the Motion History Questionnaire (MHQ) for the prediction of simulator sickness, a form of motion sickness experienced by pilots training in ground-based flight simulators. Four MHQ scoring keys were compared: (1) the original MHQ key which had been validated on a sample of U.S. Navy student pilots exposed to Coriolis forces, (2 and 3) two keys which had been validated on a sample of civilian college students exposed to simulated ship motions, and (4) a simulator sickness key empirically derived in the present research and cross-validated. Navy and Marine Corps aviators (N = 456) filled out the MHQ prior to their regularly scheduled flight simulator training and were divided into validation and cross-validation samples. All scoring keys were predictive of reported symptoms of sickness, but highest correlations were obtained with the empirically-derived simulator sickness (SS) key. It is suggested that the SS key be used for self-testing so that pilots may be made aware of their risk for developing simulator sickness.

Aerospace Medicine↗

CT analysis of metastatic neoplasms of the kidney. Comparison with primary renal cell carcinoma.

The CT findings in 32 patients with pathologically proven metastases to the kidney were compared to findings in 74 patients with renal cell carcinoma. Fourteen CT criteria were chosen to describe and characterize the lesions and 2 radiologists evaluated the CT images retrospectively according to these criteria. Renal metastases were characterized as small, multiple, bilateral, wedge-shaped, less exophytic, and located within the renal capsule. Renal cell carcinomas were single, unilateral, nonwedge-shaped, and exophytic, and easily transgressed the renal capsule. The sensitivity of CT to discriminate renal cell carcinoma from renal metastasis was 93.2% for renal cell carcinoma, and to discriminate renal metastasis from renal cell carcinoma was 75.0% for renal metastases by computer posterior probabilities. This study indicates that CT is useful for distinguishing these clinically important tumors. By using posterior probability, some unnecessary biopsies may be avoided.

Adult↗

Comparison of a PACS workstation with conventional film for interpretation of neonatal examinations: a paired comparison study.

The diagnostic value of neonatal examinations using picture archiving and communication systems (PACS) was compared with that of conventional radiographs. A total of 202 consecutive chest or abdominal radiographs from the newborn intensive care unit were digitized for display on a commercially available PACS console. Experimental design was a paired comparison study. Plain films and PACS images were reviewed alternately in unbiased fashion. After the examination was evaluated using the second modality, any change in diagnosis or confidence in diagnosis was noted. Overall evaluation showed slight preference for the PACS modality. Change of diagnosis or in confidence of diagnosis was more than twice as likely to occur with evaluation of PACS (35%) after hardcopy than with evaluation of conventional radiographs (14%) after PACS. Of the variety of image processing features available on PACS, only window and leveling were judged to be of significant value. These results indicate that PACS and conventional radiographs of the neonatal chest and abdomen are of similar diagnostic value.

Humans↗