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Biomedical subjects

K S Berbaum

Publications and source records attributed to K S Berbaum.

At least 91 records · Page 5Linked to original sources
PubMed1989

Impact of clinical history on radiographic detection of fractures: a comparison of radiologists and orthopedists.

Are the methods used by radiologists in interpreting imaging studies different from those of attending physicians? We evaluated the influence that knowledge of localizing clinical signs has on the accuracy of fracture detection by orthopedic surgeons and compared the results with those of an identical study of radiologists performed earlier. The orthopedists studied had the same degree of experience as the radiologists. Forty radiographs of the extremities were examined twice by seven orthopedic surgeons. In 26 cases, a subtle fracture was present; 14 cases were normal. During one interpretation of the radiographs of each case, the precise location of pain, tenderness, or swelling was provided; during the other, this information was withheld. Analysis of receiver-operating-characteristic parameters indicates that the clues regarding location of trauma facilitate detection of fractures by orthopedists (an 11% improvement in Az, the area under the ROC curve, F[1,12] = 49.67, p less than .001). This finding is similar to the results of the earlier study with radiologists (a 6% improvement in Az, F[1,12] = 14.77, p less than .005). Statistical comparison of the two experiments showed that orthopedists depend on this information much more than do radiologists, demonstrated by a statistically significant prompting-by-specialty interaction (F[1,12] = 5.13, p less than .05). Localization clues improve ability of orthopedic surgeons to detect fractures in the trauma patient even more than they improve the ability of radiologists. The accuracy of the radiologist will suffer less than that of the orthopedist when localization clues are unavailable. Nonetheless, the findings show that localizing clues are important to both orthopedists and radiologists when searching for fractures.

Extremities↗
PubMed1989

The time course of postflight simulator sickness symptoms.

Reports of posteffects following training sessions in Navy and Army flight simulators were obtained from pilots to determine the time course of recovery from simulator sickness. Results imply that posteffects may be a more serious problem than previously considered; 45% of all those queried (N greater than 700) reported having experienced symptoms of simulator sickness; 25% of the symptoms lasted more than 1 h after leaving the simulator; and 8% lasted more than 6 h. Postexposure symptoms were classified into three categories: visuomotor (based on disturbances in oculomotor control; e.g., eyestrain), disorientation (based on disturbance in postural control; e.g., dizziness), and nausea (vagal/autonomic symptoms). A safety risk may be posed particularly by the moderately high frequency of symptoms involving postural disequilibrium. Guidelines for coping with risks are discussed.

Adaptation, Psychological↗
PubMed1989

Simulator sickness in U.S. Navy flight simulators.

Flight simulators have become a major factor in pilot training. A general finding from Navy research on simulator design is that equipment features that offer faithful representation improve pilot performance and promote pilot acceptance. To the extent that an aircraft produces motion sickness, its simulator should induce the same result. However, reports of simulator sickness appear to be increasing and a shortcoming in simulation is implied when these effects occur in simulators during maneuvers that do not occasion them in the aircraft. This article presents incidence data from surveys of the 10 simulators at 6 different Naval/Marine Corps Air Stations. Approximately 1,200 simulator flights were recorded. Some severe motion sickness symptoms were recorded and some simulators induced unsteadiness afterwards. Individuals experiencing effects may be at risk if they drive themselves home or return to demanding activities at work. The simulators which exhibited the highest incidences of sickness were helicopter simulators with cathode ray tube (CRT) infinity optics and six-degrees-of-freedom moving base systems. Of those studied, fixed-wing, fixed-base, dome displays had relatively low incidence of simulator sickness.

Aircraft↗
PubMed1988

Perception testing in surgical pathology.

A test predictive of mature pathologic expertise could be of great value in the selection of individuals entering the field. Some individuals may have an aptitude superior to others to discriminate images based on the discovery of distinctive image features. This may enhance their ability to draw pathologic conclusions from clinical images and may favorably affect their performance as pathologists. A form of the Facial Recognition Test was administered to pathology residents and faculty to test this hypothesis. Facial recognition results correlated well with resident performance measured by overall faculty ratings, but only marginally with performance measured by scores on "direct recognition" slides of the American Society of Clinical Pathologists' in-service pathology exams. These preliminary results indicate that testing of visual discrimination may be predictive of resident performance in pathology. A test of this type could eventually be useful in selection and self selection of resident candidates and in development of remedial training for residents experiencing difficulty in learning morphologic interpretation.

Humans↗
PubMed1988

Influence of clinical history upon detection of nodules and other lesions.

The authors reexamined a suspected difference in the effects of clinical information upon detection of nodules vs. more diverse lesions by directly incorporating classification specificity into detection ROC analysis. Categorical prompts, correct for specific abnormalities, led to detection superior to unprompted reading when non-nodule trials (various lesion types) were analyzed. Trials that contained pulmonary nodules, or contained no lesions but had been preceded by "possible tuberculosis" or "rule out metastatic disease" prompts, failed to demonstrate the diagnostic prompt superiority. Perceptual responses may differ when nodules are compared with more complex lesions.

Diagnostic Errors↗
PubMed1988

Pancreatic transplant imaging.

Forty-four clinical episodes of suspected (pancreas) transplant rejection in 17 pancreatic transplantation patients were reviewed retrospectively. The clinical impression of acute graft rejection, chronic rejection, or nonrejection in each episode was correlated with the results of 19 nuclear medicine, 12 ultrasound (US), and 44 magnetic resonance (MR) imaging studies. US was found to be a moderately sensitive (82%) method of detecting graft rejection. US also was effective in identifying intra- and peripancreatic fluid accumulations. Nuclear medicine imaging was also a sensitive technique (86%) and the only modality that provided physiologic information regarding graft perfusion. MR imaging allowed correct prediction of the presence or absence of graft rejection in 39 of 44 cases (sensitivity, 100%; specificity, 76%) and was an effective means of detecting pathologic fluid collections. Nuclear medicine, US, and MR imaging are all believed to be sensitive methods of detecting graft rejection and are complementary adjuncts to the clinical evaluation of pancreatic transplants.

Diagnostic Imaging↗
PubMed1988

Impact of clinical history on fracture detection with radiography.

The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information.

Fractures, Bone↗
PubMed1988

Seronegative and seropositive rheumatoid arthritis: radiographic differences.

Patients with seronegative and patients with seropositive rheumatoid arthritis (RA) have clinical, genetic, and immunologic differences. This study was undertaken to determine whether the two populations differ radiologically. Seventeen patients with seronegative RA were closely matched with seropositive control subjects. Radiographs of the hands and wrists were studied blindly, and disease severity was quantified with use of a modification of the Beaver Creek grading sheet. The following distinguishing features were also evaluated: osteosclerosis, new bone formation, carpal predominance, ankylosis (fusion), symmetry, and classical erosions. Seropositive patients had more severe disease, with larger and more numerous erosions, while the seronegative group had more osteosclerosis, carpal predominance, fusion, and new bone formation. Symmetry was equal in both groups. Although there were definite quantitative and qualitative differences between the two populations, radiologists should be cautious in using these criteria because of the great deal of overlap between the two groups.

Arthritis, Rheumatoid↗
PubMed1987

Renal arteriovenous transit times of technetium-radiolabeled chelates.

A noninvasive method was developed for quantitating the distribution of renal arteriovenous transit times of technetium-99m (99mTc) radiopharmaceuticals. Using this method, the characteristic transit times and amplitudes of the first two components of [99mTC] DTPA or MDP transit through the renal vasculature were calculated. The first component amplitude (A1) was evaluated for its ability to discriminate between 20 hypertensive patients with renovascular disease and 21 normotensive subjects. A1 was compared with three other quantitative indices: the ascending slope of the initial renal time-activity curve, the kidney-to-aorta slope ratio (K/A), and renal size. A1 nearly perfectly separated the hypertensive patients from the normotensive subjects; the ability of A1 to discriminate between these two groups is clearly superior to renal size, the initial renal slope, and K/A. We conclude that measurements of the intrarenal distribution of blood flow have distinct advantages over indices of renal blood flow that have been derived from scintillation camera measurements of 99mTc radiopharmaceuticals.

Humans↗
PubMed1987

Transfer of perceptual-motor training and the space adaptation syndrome.

Perceptual cue conflict may be the basis for the symptoms which are experienced by space travelers in microgravity conditions. Recovery has been suggested to take place after perceptual modification or reinterpretation. To elucidate this process, 10 subjects who repeatedly experienced a visual/vestibular conflict (Purkinje) over trials and days, were then tested in a similar but not identical perceptual situation (pseudo-Coriolis) to determine whether any savings in perceptual adaptation had occurred as compared to an unpracticed control group (N = 10). The practiced subjects experienced lessening dizziness and ataxia within and over sessions. Their response to the new perceptual situation was markedly less than the control group (p less than 0.001). Assessment of "adaptability," in addition to the provocative vestibular tests now in use, may improve prediction of susceptibility to the space adaptation syndrome. An adaptability trait may exist in humans which, properly measured, could be used to predict who would adapt more readily to visual/vestibular conflict and perhaps to environmental stressors in general.

Adaptation, Physiological↗
PubMed1986

Tentative diagnoses facilitate the detection of diverse lesions in chest radiographs.

The influence of clinical history upon detection has been frequently studied. In a unique investigation, detection of diverse abnormalities commonly encountered in practice was tested, and the influence of clinical history was conceptualized as suggesting a tentative diagnosis. Categorical prompts that were correct for specific abnormalities resulted in detection superior to that with unprompted reading. Prompts that were plausible but incorrect for abnormal and normal cases led to very few false-positive responses, and subsequent reports of specific abnormalities were as accurate as in unprompted reading. It is concluded that appropriate clinical history results in improved perceptual performance rather than simply improved decision-making.

Adult↗
PubMed1986

Impact of MR imaging on clinical diagnosis and management: a prospective study.

The clinical value of magnetic resonance (MR) imaging was prospectively evaluated in 189 patients referred for examination of the brain or spine. Comparison of the attending physician's diagnosis, proposed treatment, and estimated prognosis before and after MR imaging indicated a substantial effect of the additional information provided by this study. A suspected diagnosis was refined or changed in 16% of all patients, and the physician's level of confidence in the diagnosis changed in over half of the cases in which the diagnosis was unchanged. In two-thirds of all cases the physician indicated that the treatment or estimated prognosis was altered.

Brain Diseases↗
PubMed1985

Measurement and prediction of diagnostic performance during radiology training.

Faculty evaluations of residents' diagnostic performance in radiology subspecialty rotations were examined in two studies in order to ascertain whether the relative capabilities of residents change during training and to predict residents' diagnostic performance using a three-dimensional form perception test. In the first study, numeric ratings by faculty members were averaged to provide interpretive/diagnostic scores for each of 16 residents in each of 5 consecutive half-years. Sixty-seven percent of the relative differences among residents' diagnostic proficiencies persisted during training. The magnitude of these unchanging differences between individuals in diagnostic performance strongly favors resident selection based upon diagnostic potential. An additional 22% of the relative differences correlated with an abrupt change in the rank order of residents in diagnostic performance at the beginning of the second year of residency. This rearrangement of ranks may have resulted from an abrupt change in the tasks and expectations assigned to residents. In the second study, correlations between scores on a recently described Form Test and monthly faculty ratings of diagnostic performance were computed. An average diagnostic performance score for each resident was generated for all rotations combined, each of eleven subspecialties, and all rotations completed within a given half-year. Scores on the Form Test correlated well with these combined diagnostic scores, further substantiating results reported previously. Form Test scores were highly correlated with subspecialty diagnostic performance scores in subspecialties using cross-sectional imaging methods, such as neuroradiology. Although Form Test scores were poorly correlated with half-year diagnostic performance during the first year, they were highly correlated with performance beginning in the second year.

Educational Measurement↗
PubMed1984

Spatial perception testing in diagnostic radiology.

A test predictive of ultimate radiologic expertise could be of great value in the selection of individuals entering the field. Some individuals have an aptitude superior to others to perceive three-dimensional spatial relations from two-dimensional data. This may enhance their ability to draw radiologic conclusions from clinical images and may favorably affect their performance as radiologists. To test cognitive perceptual ability, a three-dimensional Visual Form Reconstruction Test (form test) was developed and administered to residents and faculty members. All subjects also completed the Thurstone Surface Development Test, a standardized test of spatial visualization ability. The form test results correlated well with resident performance, as measured by overall faculty ratings (predictive validity). Although form test and Thurstone test performance were highly correlated with each other (concurrent validity), the form test was better correlated with resident performance. Intercorrelations among the three subsections of the form test demonstrated high split-part reliability. Performance on the form test was unaffected by level of training. This suggests that an underlying aptitude was measured. These preliminary results indicate that testing of spatial visualization aptitude is predictive of resident performance in radiology. A test such as this could be useful in selection and self-selection of resident candidates.

Aptitude↗
PubMedDate not supplied

Sonography of acute appendicitis in pregnancy.

BACKGROUND: Clinical evaluation of acute appendicitis is difficult in pregnant patients. Delay in diagnosis is associated with increased fetal mortality. The purpose of our study was to assess the value of sonography in the diagnosis of acute appendicitis in pregnant women. METHODS: We obtained sonograms in 22 pregnant women suspected of acute appendicitis. All sonograms were performed using graded-compression to detect an enlarged appendix. The sonographic criteria for acute appendicitis were detection of a noncompressible blindended and tubular multilayered structure of maximal diameter greater than 6 mm. RESULTS: The sonographic findings were correlated with surgical findings in seven cases and clinical follow-up in 15 cases. Acute appendicitis was diagnosed by sonography in three of 22 patients, and in all but one was confirmed by surgical and pathologic findings. In the remaining 19 patients, 15 improved on clinical followup; three were shown to have a normal appendix at surgery and one had focal acute inflammation at the tip of the appendix. CONCLUSIONS: Our experience suggests that graded-compression sonography is a useful procedure in pregnant patients suspected of acute appendicitis and has a similar accuracy as in nonpregnant women, especially in the first and second trimester.

Acute Disease↗
PubMedDate not supplied

Does a normal small-bowel enteroclysis exclude small-bowel disease? A long-term follow-up of consecutive normal studies.

The purpose of our study was to determine if a normal small-bowel enteroclysis excludes small-bowel disease in adult patients, using long-term follow-up as the major reference standard. We reviewed 193 consecutive small-bowel enteroclysis (SBE) studies completed during a period from January 1987 to February 1989, of which 83 were judged to be normal at the time of the study. Eight of these latter patients were excluded due to inadequate follow-up. The indications included detection of gastrointestinal bleeding, small-bowel obstruction, Crohn's disease, nonspecific abdominal pain, chronic diarrhea, and a miscellaneous group. Each patient was followed for at least 3 years by chart review or until a definite diagnosis was established. Six of the 75 patients whose SBE was originally interpreted as normal were eventually judged to have small-bowel disease. The remaining 69 patients were judged to be free of small-bowel disease by autopsy, surgical laparotomy, endoscopic observation or biopsy, or long-term follow-up for at least 3 years. Therefore, a normal SBE correctly excluded small-bowel disease in 69 of our 75 patients (true negatives) and failed to diagnose disease in six patients (false negatives), for a specificity of .92 +/- .03 (SE). In this experience, SBE was sufficiently specific in most patients to exclude small-bowel disease.

Adolescent↗