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Biomedical subjects

J D Newell

Publications and source records attributed to J D Newell.

At least 19 recordsLinked to original sources
PubMed1991

Imaging of the expanded polytetrafluoroethylene prosthetic diaphragm following extrapleural pneumonectomy for mesothelioma.

Extrapleural pneumonectomy, which usually requires placement of a prosthetic hemidiaphragm, can be offered to approximately 24% of patients with malignant mesothelioma. Expanded polytetrafluoroethylene (Gore-Tex) has superior physical characteristics for diaphragmatic grafting and is the material of choice at the authors' institutions. This article describes conventional radiography and computed tomography findings in three patients who underwent extrapleural pneumonectomy. A freshly placed Gore-Tex prosthetic diaphragm appears as a radiolucent crescent-shaped band at the inferior border of the hemithorax and could be confused with a pneumoperitoneum. With time, the lucent crescent becomes thinner and eventually becomes radiopaque; it may be confused with a calcified diaphragm.

Calcinosis↗
PubMed1991

Expiratory computed tomography for assessment of suspected pulmonary emphysema.

Results of computed tomography of the lung performed at two levels in upper lung zones at full inspiration and full expiration were compared with results of tests of ventilatory function, lung mechanics, and single breath carbon monoxide diffusing capacity in 64 subjects, many of whom had some form of airflow obstruction. From the CT scans, the mean percentage of pixels in the range -900 to -1,024 Hounsfield units, or pixel index, was determined for each subject. The highest correlations of pixel index with physiologic variables consistent with a diagnosis of emphysema were observed for CT taken at full expiration. In some subjects, the inspiratory CT would give a "false positive" for emphysema when the hyperaeration observed at inspiration was not observed at expiration. We believe that the CT scan taken at full expiration can effectively reveal the abnormal permanent enlargement of airspaces which defines emphysema and provides a noninvasive method of assessing lung morphology in the living human subject.

Adult↗
PubMed1991

Paranasal sinuses on MR images of the brain: significance of mucosal thickening.

One hundred twenty-eight patients were examined prospectively to determine the significance of mucosal thickening seen in the paranasal sinuses during routine MR imaging of the brain. On the basis of responses to a questionnaire, each patient was categorized as symptomatic (n = 60) or asymptomatic (n = 68) for paranasal sinus disease. Patients were categorized further on the basis of the maximal mucosal thickening seen by MR in any paranasal sinus. A modified t test was used to compare the prevalence of various degrees of mucosal thickening between symptomatic and asymptomatic groups. Statistically significant differences between the groups were seen only in those patients with normal sinuses and in those with 4 mm or more of mucosal thickening. We conclude that mucosal thickening of up to 3 mm is common and lacks clinical significance in asymptomatic patients. An ancillary finding is that 1- to 2-mm areas of mucosal thickening in the ethmoidal sinuses occur in 63% of asymptomatic patients. This minimal mucosal thickening in the ethmoidal sinuses is thought to be a normal variant, possibly a function of the physiologic nasal cycle.

Adolescent↗
PubMed1989

Esophageal carcinoma multiplex with gastric metastasis.

We describe here the radiographic findings in a patient with multiple synchronous squamous carcinomas of the esophagus with a large metastasis to the gastric cardia. Radiographic documentation of this constellation of tumor involvement has not previously been reported. The mechanisms of esophageal metastasis are reviewed.

Carcinoma, Squamous Cell↗
PubMed1989

Pulmonary needle embolism from intravenous drug abuse.

Although the embolization of catheters and other foreign bodies in blood vessels is a well-known happening, needle embolization has rarely been reported. We describe here an instance in which a hypodermic needle broke in a man's skin during cocaine injection. The needle fragment was observed to migrate within a short time to the periphery of the left lung. The patient did not develop complications. The limited literature available indicates that such peripheral embolization usually follows a benign course.

Adult↗
PubMed1988

Arteriovenous and capillary hemangiomas of the interventricular septum.

The case of a patient with two extremely unusual types of hemangioma is presented. The arteriovenous and capillary hemangiomas of the interventricular septum were discovered on coronary angiography performed for chest pain. Echocardiography confirmed the diagnosis. Successful surgical excision was performed.

Adult↗
PubMed1988

Computed radiographic evaluation of simulated pulmonary nodules. Preliminary results.

We evaluated the capabilities of a computed radiography system (CRS) and a standard radiography system (SRS) in the detection of simulated solitary pulmonary lung nodules of various sizes and contrast. A phantom simulated the pulmonary anatomy, and specially shaped plexiglass disks were externally mounted to simulate solitary pulmonary nodules of different diameters and thicknesses. ROC curves were generated based on the performance of each of the radiologists observing each film set. In this preliminary study, the overall performance for both the CRS and the SRS were comparable in detecting simulated pulmonary nodules.

Humans↗
PubMed1988

Chest radiographic abnormalities in Lennert's lymphoma.

In reviewing the medical records of ten patients with Lennert's lymphoma, we found chest radiographic abnormalities in five cases. Two cases had hilar and mediastinal adenopathy without associated parenchymal or pleural disease, and three cases had isolated pulmonary parenchymal abnormalities. In one patient, both the chest radiograph and the histologic findings, obtained by open lung biopsy, mimicked miliary granulomatous disease. This article emphasizes the need to be alert to this aggressive T-cell neoplasm, since its clinical course differs significantly from some of the diseases it tends to imitate. By being aware of the entity and by using thorough pathologic and immunopathologic techniques, difficult cases of Lennert's lymphoma can be successfully diagnosed.

Aged↗
PubMed1988

Immunoglobulin E anaphylaxis in rabbits: mechanisms of pulmonary resistance and compliance changes.

Factors causing changes in pulmonary resistance and dynamic compliance with immunoglobulin (Ig) E anaphylaxis in spontaneously breathing rabbits were assessed in ventilated rabbits using tantalum bronchography and wet-to-dry wt ratios. Ventilated rabbits demonstrated changes in resistance and compliance similar to spontaneously breathing rabbits. Chlorpheniramine pretreatment prevented increases in resistance but not decreases in compliance. Anaphylaxis constricted small (less than 1 mm) airways 20.9 +/- 16.0% (mean +/- SD) and intermediate (between 1 and 3 mm) airways 21.8 +/- 19.8%. Chlorpheniramine (10 mg/kg) prevented small airway changes and attenuated those in intermediate airways. Chlorpheniramine prevented histamine-induced constriction of small (23.6 +/- 15.7%) and intermediate (17.6 +/- 15.0%) airways. Lung wet-to-dry wt ratios were unchanged. Changes in resistance and compliance during rabbit IgE anaphylaxis are not due to changes in tidal volume or frequency. Histamine, via H1 receptors, is the principal mediator of pulmonary resistance increases but not dynamic compliance reductions. Chlorpheniramine-sensitive increases in resistance are caused by constrictions of intermediate and small airways, whereas the chlorpheniramine-resistant decrease in compliance is not caused directly by constriction of the smallest measurable airways (0.25 mm) or changes in lung water.

Airway Resistance↗
PubMed1987

Quantitative computed tomography evaluation of benign solitary pulmonary nodules.

A retrospective evaluation of stable solitary pulmonary nodules was completed in 14 patients using a GE 8800 CT scanner and the Computerized Imaging Reference Systems, Inc., computed tomography chest phantom. Patients with a stable nodule for at least 24 months and no evidence of calcification within the nodule by plain radiography were selected for the study. Using the phantom, a quantitative assessment of nodule density was done in each patient. Of 14 nodules, five were categorized as benign. Linear conventional tomography was performed on these five patients, and only one had evidence of benign calcifications. All patients lived in an area endemic for Coccidioides immitis and six of 14 had culture, serologic, or skin test evidence of previous infection with C. immitis. Two of these six patients had nodules that were characterized as benign using the computed tomography chest phantom. This study indicates that the computed tomography chest phantom is useful in identifying benign nodules in patients living in an area endemic for C. immitis pulmonary infections.

Adult↗
PubMed1987

Diagnostic imaging for evaluation of the pediatric chest.

Diagnostic imaging procedures for evaluation of the chest, airways, and sinuses in the infant and child have been reviewed. Procedures include plain radiographs, fluoroscopy, esophagram and UGI, computed tomography, conventional tomography, MRI, digital subtraction angiography, angiography, interventional radiology, ultrasound, bronchography, and pulmonary and esophageal scintigraphy. Knowledge of these imaging procedures aids the physician in ordering the proper examination for the efficient diagnostic workup.

Angiography↗
PubMed1986

Personal computer needs for the radiologist.

This article reviews the computer system hardware and software, applications programs, and computer network services that are available on microcomputers for use by the radiologist. The American College of Radiology Institute computer network is described, which is specifically designed to help the practicing radiologist.

Computers↗
PubMed1986

Radiologic total lung capacity measurement. Development and evaluation of a computer-based system.

The development of a computer-based radiologic total lung capacity (TLC) measurement system designed to be used by non-physician personnel is detailed. Four operators tested the reliability and validity of the system by measuring inspiratory PA and lateral pediatric chest radiographs with a Graf spark pen interfaced to a DEC VAX 11/780 computer. First results suggest that the ultimate goal of developing an accurate and easy to use TLC measurement system for non-physician personnel is attainable.

Adult↗
PubMed1985

Radiographic findings of pulmonary coccidioidomycosis in neonates and infants.

Radiographic findings in four recent cases of pulmonary coccidioidomycosis are reported. Focal consolidation and diffuse nodular densities were observed at one point during the course of the illness in all four patients. Pleural effusion or mediastinal adenopathy was not seen. Hilar adenopathy developed in one patient after 61/2 months. Hyperaeration was noted in all patients. One patient survived the pneumonia and had subsequent clearing of the infiltrates. Cavitation was not seen in any of the patients. The insidious onset and nonspecific and often misleading clinical and laboratory findings in pulmonary coccidioidomycosis infection in neonates and infants may seriously delay the correct diagnosis in this highly fatal disease. A knowledge of the characteristic radiographic manifestations of this pulmonary disease may be helpful to the clinician.

Coccidioidomycosis↗