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Biomedical subjects

B S Slasky

Publications and source records attributed to B S Slasky.

At least 19 recordsLinked to original sources
PubMed1994

Subjective and objective assessment of image quality--a comparison.

Forced-choice just noticeable difference (JND) studies are extremely sensitive to image quality variations that are below the threshold at which the differences are apparent to or definable by the observer. Paired comparisons of 4K and 2K laser-printed posteroanterior chest images consistently demonstrated that although images are viewed as comparable by radiologists, when forced to choose the better ("sharper") image, they actually select the higher-resolution images in 83% of the paired observations. We conclude that small differences in image quality may be detectable even in image sets which are considered to be comparable by subjective assessments.

Differential Threshold↗
PubMed1991

Skeletal muscle density: effects of obesity and non-insulin-dependent diabetes mellitus.

Obesity is associated with increased lean mass but its effects on lean-tissue density are less clear. To examine the effects of obesity and non-insulin-dependent diabetes mellitus (NIDDM) on lean-tissue composition and density, cross-sectional computed tomography (CT) scans of the midthigh were obtained in 20 men of various weights. Obesity was associated with increases in thigh-adipose (r = 0.75) and lean-tissue volumes (r = 0.52) and with reduced density of lean tissue (r = -0.73). The increased lean tissue in obesity was due to a nonadipose tissue component with a density below the normal range of muscle, an effect compounded by NIDDM, whereas normal-density muscle volume was unchanged.

Adipose Tissue↗
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

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↗
PubMed1987

Posttransplantation cyclosporine-induced lymphoproliferative disorders: clinical and radiologic manifestations.

Fifteen allograft transplant recipients acquired lymphoproliferative disorders after immunosuppressive therapy with cyclosporine and steroids. Many of these lymphoproliferative disorders regressed or disappeared completely after reduction of cyclosporine dose. This disease has several aspects that distinguish it from usual posttransplantation lymphomas that occur with regimens that do not contain cyclosporine. The time course from transplantation to onset of lymphoma is relatively short, with an average of approximately 8 months. Organs show a wide spectrum of abnormalities typical of other immunosuppression-associated lymphomas, but there is unique sparing of the central nervous system. The tumor is also unique in that it responds to a decrease in the cyclosporine dose.

Adolescent↗
PubMed1986

Prospective study of computed tomography in initial management of blunt abdominal trauma.

Physical examination is often unreliable in the evaluation of blunt abdominal trauma. The utility of computed tomography (CT) in the early management of abdominal trauma in the absence of definite signs is controversial. CT was prospectively evaluated as an adjunct to physical examination in the initial assessment of blunt abdominal trauma. Indications for emergency abdominal CT were a stable patient with an equivocal abdominal examination, closed head injury, spinal cord injury, hematuria, or pelvic fracture. One hundred twenty patients were studied. CT was accurate in 98.3% of these patients. With associated head injury, combining head and abdominal CT proved to be expeditious. Splenic, hepatic, and renal injuries were reliably detected with CT. Minor injuries which did not require laparotomy were reliably diagnosed. Patients with acute pancreatic injuries may have normal CT findings. Eighty-six per cent of laparotomies were therapeutic. In conjunction with close clinical monitoring, CT was reliable in evaluation of blunt abdominal trauma in a selected group of patients.

Abdominal Injuries↗
PubMed1986

Long-term prognosis of survivors of Pneumocystis carinii pneumonia. Structural and functional correlates.

Limited data exist detailing the long-term sequelae of Pneumocystis pneumonia. Open lung biopsies were obtained in seven renal transplant recipients within 48 hours of the onset of respiratory failure. Biopsy specimens and simultaneous chest roentgenograms were graded without clinical information according to the severity of alveolar damage and pulmonary infiltrates, respectively. Evaluation of pulmonary function and exercise physiology were performed 15 to 21 months after their illness. Pulmonary function indices were normal except FRC (2.65 +/- 0.56 L or 77 +/- 16 percent of predicted) and Dsb (20.0 +/- 7.2 ml/min/mm Hg or 79 +/- 19 percent of predicted). Two patients developed arterial desaturation with exercise. Alveolar damage scores correlated with later exercise arterial desaturation (r = 0.88, p less than 0.05). Simultaneous roentgenographic scores correlated with later abnormalities of Dsb (r = 0.81, p less than 0.05). Mild residual abnormalities of pulmonary function were found in five of seven adult survivors of Pneumocystis pneumonia. These abnormalities correlated with pathologic and radiographic features of the acute illness.

Adult↗
PubMed1985

Computed tomography appearance of melanoma of nasal cavity.

Melanoma of the nasal cavity is a mucosal lesion that is quite rare. It comprises less than 1% of all melanomas and constitutes 4% of primary malignant tumors of the nasal cavity. The computed tomography appearance of this entity is discussed and found to be nonspecific.

Aged↗
PubMed1985

Tracheal chondrosarcoma with an overview of other tumors of the trachea.

Chondrosarcomas of the trachea are extraordinarily rare tumors, with only four cases documented in the English literature. An additional case is reported with conventional and computed tomography correlation. Because primary tumors of the trachea are such rare neoplasms, a review of the subject is presented to put chondrosarcomas of the trachea into perspective. Malignant tumors are slightly more common than benign tumors of the trachea and occur more frequently in adults. The most common tumor involving the trachea is carcinoma, accounting for 80 to 90% of all cases. This, however, represents only 0.2% of all malignancies of the respiratory tract.

Aged↗
PubMed1985

Acute respiratory failure due to Pneumocystis carinii pneumonia: clinical, radiographic, and pathologic course.

The clinical, radiographic, and pathologic correlates of acute respiratory failure due to Pneumocystis carinii pneumonia were studied in 12 renal transplant patients treated with cyclosporin (CS) and prednisone. Six patients required only supplemental oxygen, while the other six patients developed the adult respiratory distress syndrome (ARDS) requiring prolonged mechanical ventilation despite similar predisposing factors and prompt initiation of therapy. Ten (83%) patients survived. Increased frequency of human leukocyte antigen (HLA) DR6 was noted in six of the 11 patients tested. The resolution of radiographic infiltrates was significantly slower in ARDS patients; however, there was no apparent difference in the severity of early alveolar damage between the two groups. There was also no association between the development of ARDS due to P. carinii pneumonia and the mean daily dose of CS and prednisone, the presence of cytomegalovirus infection or pneumonia, HLA-DR6 antigen, or initial hypoxemia.

Acute Disease↗
PubMed1985

Sonography of cholesterol in the biliary system.

The sonographic features of cholesterol within the biliary system are reviewed and a new sign is described. That cholesterol causes high reflecting echoes and may cause shadowing has been known; however, its ability to cause reverberatory artifactual echoes has not been previously appreciated. These sonographic features, while not specific, should favor the diagnosis of cholesterol stones and cholesterol polyps in the appropriate clinical situation.

Bile Duct Diseases↗
PubMed1984

Malignant myositis ossificans: occult gastric carcinoma presenting as an acute rheumatic disorder.

A patient developed ossifying skeletal muscle metastases from a primary gastric mucin-producing adenocarcinoma. The unusual nature of skeletal muscle metastases and the inflammatory-like syndrome associated with heterotopic ossification is reviewed. It is suggested that this case of 'neoplasm-induced post-traumatic myositis ossificans' may be caused by the interaction of local haemorrhage and thrombosis, mucin-producing tumour implants, and the presence of large quantities of gamma-carboxyglutamic acid, an amino acid associated with the calcification of bone matrix formation.

1-Carboxyglutamic Acid↗
PubMed1984

Diabetes mellitus: the predominant cause of bilateral renal enlargement.

The authors reviewed 102 cases of bilateral renal enlargement seen on excretory urography (excluding hydronephrosis and duplex kidneys) to determine the clinical significance of this finding. Associated abnormalities were found in 48 patients, including diabetes mellitus in 29; nondiabetic obesity, large body structures, or chronic steroid use in 16; acromegaly in 1; and unknown etiology in 37, 2 of whom were found to have diabetes five years later. Because of the striking preponderance of diabetes in this study, a fasting blood glucose analysis is recommended for patients with unexplained bilateral renal enlargement on excretory urography.

Diabetes Complications↗
PubMed1983

Germ cell tumors complicated by pneumothorax.

Spontaneous pneumothorax is an unusual consequence of pulmonary metastases. This complication occurs mainly in children and adolescents with primary osseous sarcomas and is extremely rare in patients with pulmonary metastases secondary to carcinomas. Germ cell tumors have a proclivity to metastasize to the lung, but few instances of pneumothorax have been recorded. The authors present 3 cases of pneumothorax secondary to pulmonary metastases from germ cell tumors, both gonadal and extragonadal in type.

Adult↗
PubMed1983

Bone-forming gastric metastases in muscle-computed tomographic demonstration.

Bone-forming metastases to soft tissues and muscle are a rare entity. An unusual case of heterotopic ossification occurring within metastases to muscle arising from a primary gastric adenocarcinoma is reported. No bone was found in the primary gastric malignancy. There is one prior report of ossification in muscle occurring in metastases from gastric malignancy, but no previous computed tomographic demonstration of this. The mechanism of osseous metaplasia is discussed, but its precise morphogenesis remains obscure.

Adenocarcinoma↗
PubMed1983

Therapeutic implications of an intraoral malignancy complicated by Darier-White's disease.

A 69-year-old white male with a long history of severe Darier-White's disease presented with an extensive intraoral malignancy. High dose external supervoltage radiotherapy (Cobalt-60) to the tumour caused remarkable clearing of the hyperkeratotic lesions involving the overlying skin. Subsequently, surgical resection of the tumour with staged reconstruction of the jaw was carried out. The presence of the skin disorder did not adversely affect the surgical procedure nor the subsequent wound healing. Darier-White's disease, therefore, should not be a deterrent to radical radiotherapy and/or surgery for concomitant malignancy.

Aged↗