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Biomedical subjects

L A Cooperstein

Publications and source records attributed to L A Cooperstein.

16 recordsLinked to original sources
PubMed1997

Synchronous multicentric osteosarcoma: the case for metastases.

OBJECTIVE: There is a current debate whether multicentric osteosarcoma represents synchronous multiple primary osteosarcomas or metastatic disease. The purpose of this report is to evaluate the etiology, presentation, and classification of this entity. DESIGN AND PATIENTS: Six patients ranging in age from 7 to 29 years were studied. The clinical, radiographic, and pathologic findings are reported. In addition, a review of the literature was undertaken. RESULTS: The clinical courses of our six patients as well as a review of the literature suggest that multicentric osteosarcoma represent one extreme of a continuous scale of metastatic osteosarcoma rather than multiple synchronous primary tumors. The presentation is unusual and the clinical behavior distinctive, but the mechanism of spread remains the same: blood-borne and lymphatic-borne. CONCLUSIONS: Our experience with these six patients supports the concept in the recent literature that synchronous osteosarcoma is one extreme of the spectrum of metastatic osteosarcoma. Its unique features are: (1) multiple radiodense lesions that present simultaneously with or without pulmonary metastases; (2) a single "dominant" lesion with multiple smaller lesions; and (3) a uniformly rapid, fatal prognosis. Osteosarcoma should be regarded as a metastatic disease, even when only a single primary lesion is found at the initial presentation.

Adolescent↗
PubMed1990

A subluxing arthropathy associated with the anti-Jo-1 antibody in polymyositis/dermatomyositis.

Of 180 patients with polymyositis/dermatomyositis (PM/DM) seen at the University of Pittsburgh and affiliated hospitals since 1975, 21 of 100 tested positive for the anti-Jo-1 antibody. Sixteen of the 21 patients were women and 18 were white. Fifteen had adult PM, 4 had myositis in overlap with scleroderma, and 2 had adult DM. Evidence of interstitial lung disease was found in 12 of 18 anti-Jo-1 positive patients (67%), but in only 15 of 79 anti-Jo-1 negative patients (19%) (P less than 0.0002). The 21 anti-Jo-1 positive patients were divided into 3 separate groups based on the observed articular findings. Four patients had a deforming, predominantly nonerosive arthropathy with subluxations of the distal interphalangeal joints, especially the thumbs. Eight patients had a nondeforming arthropathy primarily affecting the small joints of the hands, wrists, shoulders, and knees. Those with deformities had a longer duration of arthritis compared with those with nondeforming arthropathy (mean 14.5 years versus 3.3 years). Nine anti-Jo-1 positive patients had no joint arthropathy. Three of 4 patients with deformities have required articular reconstructive surgery for subluxation, with 2 having associated subcutaneous calcinosis.

Adolescent↗
PubMed1990

Effect of two rating formats in multi-disease ROC study of chest images.

ROC methodology has been expanded in recent years to include multi-disease experiments. To accommodate these changes, different rating formats, general or disease specific, can be used. No experimental data are available concerning the possible effects of the rating format on the results of these studies. We performed a multi-observer, multi-disease study in which 196 chest images were rated using a format where each disease was evaluated individually and one in which the cases were evaluated without scoring a specific disease. The results indicate that for our data set, the overall assessment of accuracy was not significantly affected by the study format used. Thus, in spite of the difficulties in selecting appropriate controls and the necessity of reassessing sample size considerations, the disease-specific format appears to produce an assessment of accuracy equivalent to that produced by the general format. This equivalence permits the use of the disease-specific approach since it more closely simulates the readers' true environment and is more appropriate for comparing imaging systems that may have a relative accuracy that is disease specific.

Diagnosis, Differential↗
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

The effect of clinical history on chest radiograph interpretations in a PACS environment.

The effect that accompanying patient information has on diagnostic accuracy in radiologic interpretation has been studied by many researchers but remains a matter of contention. Experiments in the past emphasized the chest film because this procedure is the one done most frequently in radiology. However, with the increasing importance of digital imaging, the role of patient history in these procedures should be assessed. The use of a model computerized patient history in the interpretation of digitized chest images that were displayed on a high-resolution workstation was studied. Two hundred forty-seven selected posteroanterior chest images that indicated disease and that indicated no disease were interpreted in random sequence by five board-certified radiologists, with and without accompanying patient histories. Readers were prompted by the response forms to evaluate images for the possible occurrence of interstitial diseases, nodules, or pneumothorax. No significant differences (P = .05) in the detection of these abnormalities were noted between case readings with and without history for any of the radiologists or for the group as a whole. However, this methodology reflects a direct interpretation approach. The results of this study may not necessarily be applicable to individual prompts, different imaging procedures, or other abnormalities.

Hospital Information Systems↗
PubMed1990

Receiver operating characteristic analysis of chest image interpretation with conventional, laser-printed, and high-resolution workstation images.

The differences among radiologists in interpreting conventional and digitized images obtained with different radiologic procedures is an important research issue in these times of implementation and growth of the digital modalities. The authors performed a multiobserver study to determine the performance of radiologists reading posteroanterior conventional radiographs, digitized radiographs laser printed onto film, and images displayed on a high-resolution workstation (video monitor). A total of 300 images were evaluated by seven radiologists who recorded their ordinal confidence rating of the presence or absence of one or more of the following abnormalities: interstitial disease, nodule, and pneumothorax. Receiver operating characteristic analysis showed statistically significant differences for the detection of different abnormalities by individual readers. The group as a whole showed a significant reduction in observer performance for the detection of interstitial disease and pneumothorax when the laser-printed radiographs or the workstation was used rather than conventional radiographs.

Computer Systems↗
PubMed1990

Does knowledge of the clinical history affect the accuracy of chest radiograph interpretation?

To examine the effect that a concise, objective, and potentially computer-extractable history would have on diagnostic accuracy in the interpretation of chest radiographs, we designed and tested a computerized patient-history form that could be integrated realistically into the clinical environment. We performed a series of studies in which 247 posteroanterior normal (79) and abnormal (168) chest radiographs were interpreted by four board-certified radiologists, both with and without accompanying clinical histories. The radiologists recorded their confidence rating of the presence or absence of one or more of the following abnormalities: interstitial disease, nodule, and pneumothorax. Analysis of receiver operating characteristics showed that, with the exception of interpretation of one abnormality by one radiologist, there were no statistically significant differences (p less than .05) between cases interpreted with and without the history form for any of the radiologists. The results of our study suggest that knowledge of clinical history does not affect the accuracy of chest radiograph interpretations for the detection of interstitial disease, nodules, and pneumothoraces. These results may not be applicable to other clinical situations.

Humans↗
PubMed1990

Acetabular anatomy and the transacetabular fixation of screws in total hip arthroplasty.

An anatomical and radiographic study was undertaken to determine the safest zones in the acetabulum for the transacetabular placement of screws during uncemented acetabular arthroplasty. To avoid injury to intrapelvic structures, which are not visible to the surgeon during placement of the screws, cadavera were studied to define the location of these structures with respect to fixed points of reference within the acetabulum. Four clinically useful acetabular quadrants were delineated. The quadrants are formed by drawing a line from the anterior superior iliac spine through the center of the acetabulum to the posterior fovea, forming acetabular halves. A second line is then drawn perpendicular to the first at the mid-point of the acetabulum, forming four quadrants. The posterior superior and posterior inferior acetabular quadrants contain the best available bone stock and are relatively safe for the transacetabular placement of screws. The anterior superior and anterior inferior quandrants should be avoided whenever possible, because screws placed improperly in these quadrants may endanger the external iliac artery and vein, as well as the obturator nerve, artery, and vein. The acetabular-quadrant system provides the surgeon with a simple intraoperative guide to the safe transacetabular placement of screws during primary and revision acetabular arthroplasty.

Acetabulum↗
PubMed1989

Three-dimensional angio-computed tomography. New technique for imaging the acetabulum and adjacent vessels in a patient with acetabular protrusio.

An arterial injury is an infrequent but potentially lethel occurrence after primary or revision total hip arthroplasty complicated by an acetabular protrusio. Frequently, a plain radiograph and an arteriogram are used to assess the major arteries around the hip. The limitations of these techniques are well documented. A novel technique for documenting the spatial relationships of the external iliac and common femoral arteries to the acetabulum employs an arterial study combined with a three-dimensional computed scan. An angiocatheter is inserted by conventional radiographic technique and a standard computed scan with 3-mm sections is obtained and reconstructed to a three-dimensional image. The scan provides an accurate three-dimensional image of the osseous architecture and arterial images around the acetabulum. Even in the presence of a metallic arthroplastic component, the resolution of the three-dimensional angio-computed scan is sufficient to identify the external iliac artery adjacent to the pelvis.

Acetabulum↗
PubMed1988

Storage phosphor radiographs vs conventional films: interpreters' perceptions of diagnostic quality.

We compared storage phosphor images with high-quality conventional film-screen images by evaluating physicians' perceptions of image quality and their levels of confidence in making diagnostic interpretations. Eight physicians each examined 11 posteroanterior storage phosphor chest images (obtained with an experimental high-resolution storage phosphor system) side by side with conventional film images of the same patients. The storage phosphor images were obtained only minutes after the conventional radiographs were obtained. Storage phosphor images were digitally printed onto films in two different formats: a full-size (12 X 14 in. [30.5 X 35.6 cm]) and a half-size format of four computer-processed, minified images (6 X 7 in. [15.2 X 17.8 cm] each). Most of the responses rated the quality and resolution/sharpness of conventional images, as well as their ability to display the complete lung field, as either "excellent" or "good"; however, the storage phosphor images received significantly better ratings (p less than .05). Computer-processed minified versions of the storage phosphor images also received better ratings than did the conventional images. When the physicians were asked to rate their confidence level in making diagnoses with each of the two techniques, in 74 of 88 cases they indicated that their level of confidence would be at least as high when using the storage phosphor images as when using the conventional images.

Humans↗
PubMed1987

Adult-onset Still's disease. Clinical course and outcome.

We reviewed the long-term natural history of 21 adult-onset Still's disease patients. Patient subsets were identified according to clinical course patterns. These included monocyclic systemic disease in 4, polycyclic systemic disease in 2, chronic articular monocyclic systemic disease in 10, and chronic articular polycyclic systemic disease in the remaining 5 patients. Functional outcome differed according to course patterns and the extent of articular involvement. Systemic manifestations, per se, did not contribute to poor functional prognosis. Chronic articular disease had the worst outcome: 27% evolved to functional class III status, compared with none in the cyclic systemic groups. Those patients who had a chronic articular pattern or a polyarticular onset and course were at higher risk to develop disabling arthritis. An aggressive approach to therapy, including the early use of remittive agents, should be considered in these patient subsets.

Adolescent↗
PubMed1986

Acetabular fractures: three-dimensional computer tomographic imaging and interactive surgical planning.

Three-dimensional imaging can provide a valuable perceptual link between conventional radiographs and axial computed tomographic scans in the evaluation of complex acetabular fractures. With the 3D83 computer program, three-dimensional images can be generated to correlate with standard radiographic views. Unique images can also be created that offer perspectives unobtainable by conventional radiography. More sophisticated interactive techniques allow computer simulation of surgical approaches.

Acetabulum↗
PubMed1985

Three-dimensional computed tomography of acetabular fractures.

Computer programs that produce 3D surface reformations from sets of contiguous axial CT scans were used in evaluating a variety of acetabular fractures in 20 patients. The 3D images were easily correlated with plain radiographs, and new views were produced that provided a unique perspective not obtainable by conventional radiography. The 3D images were useful in complex displaced fractures in cases in which the interpretation of plain radiographs was difficult. Plain radiographs and conventional CT scans were more sensitive than the 3D images in detecting undisplaced fractures.

Acetabulum↗