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Biomedical subjects

W R Webb

Publications and source records attributed to W R Webb.

At least 163 records · Page 9Linked to original sources
PubMed1984

Evaluation of magnetic resonance sequences in imaging mediastinal tumors.

Ten patients having a mediastinal tumor were studied with magnetic resonance imaging (MRI) using from two to four imaging sequences. Seven had bronchial carcinoma and three had benign lesions. The sequences included the spin-echo technique with repetition time (TR) values of 0.5, 1.0, and 2.0 sec and echo time (TE) values of 28 and 56 msec, and the inversion-recovery technique. The signal-intensity ratios of the mediastinal mass and mediastinal fat, which are a measure of image contrast, were compared for the different imaging sequences. Also signal-to-noise ratios were measured relative to both mediastinal fat and mediastinal mass. With spin-echo imaging, decreasing the TR value resulted in an increase in mass/fat contrast in all patients, making the masses easier to detect, but this also resulted in decreased signal-to-noise ratios. Inversion-recovery imaging with the sequence used resulted in a greatly increased mass/fat contrast, because of a relative decrease in signal from the mass. However, in two of four patients studied with this technique, the mass was so low in intensity that it could not be distinguished from the trachea or mediastinal vessels, and in one of these four, a lung nodule was also invisible. Spin-echo imaging with both short and long TR values provides good tissue contrast and good signal-to-noise ratios.

Adenoma↗
PubMed1984

Metabolic effects of fructose diphosphate in hypoxic and ischemic states.

A number of methods have been used to protect organ systems and cells from the ravages of ischemia and hypoxia. Some have attempted to reduce the metabolic needs, such as by hypothermia, cardioplegia, and slow calcium channel blockers. Others have attempted to provide the metabolic needs, such as by cold blood cardioplegia and solutions of readily metabolized substrates. Our work has centered on the use of fructose 1-6-diphosphate, which can be used anaerobically after glycolysis has been stopped by the effects of anoxia and acidosis. Fructose diphosphate has proved effective experimentally in ameliorating the effects of local and global ischemia of the heart. It has also been found to be of value in many hypoxic or ischemic states including traumatic, septic, endotoxic, and hypovolemic shock. The rationale and a survey of preliminary results are presented.

Animals↗
PubMed1984

Clinical NMR imaging of the chest and mediastinum.

Nuclear magnetic resonance (NMR) imaging, using the spin-echo and inversion recovery techniques, provides an excellent demonstration of normal intrathoracic anatomy, and has proven useful in the diagnosis of a number of chest diseases. Because of the absence of NMR signal from rapidly flowing blood, vascular lesions can be easily diagnosed without the use of contrast agents, and mediastinal and hilar masses can be easily distinguished from normal or abnormal vessels. On the basis of T1 values, mediastinal masses can be distinguished from normal mediastinal tissues, and using T1 and T2 values, fluid within masses can be detected. Although NMR appears to offer no great advantage relative to CT in the diagnosis of mediastinal mass, small hilar masses are much more easily distinguished from normal hilar structures using NMR. Another significant advantage of NMR is its ability to directly image in the sagittal and coronal planes with good spatial resolution. In some patients, this can be helpful in the assessment of mediastinal masses. NMR may prove helpful in the evaluation of blood flow, the noninvasive diagnosis of pulmonary embolism, and in the quantitation of lung water.

Humans↗
PubMed1983

Costal chondritis: the costal arch.

Infections of the costal cartilages lead to serious sequelae. This report deals with the diagnosis of such infections, proposed treatment, and an illustrative case history from our experience. Previous therapeutic regimens advocated excision of the entire costal cartilage if any portion was infected. In cases where the infection is confined to cartilages not involving the costal arch, this is an effective therapy. However, in infections of the costal arch, complete removal leads to gross deformity, loss of skeletal protection of the heart and liver, and chest wall instability with serious respiratory failure. Segmental cartilaginous resection followed by a period of healing and subsequent debridement of only the infected and necrotic cartilage is the preferred method for treatment of infection involving the costal arch.

Bacterial Infections↗
PubMed1983

Computed tomography of the left retrobronchial stripe.

Posterior to the left hilum, lung contacts and outlines the posterior wall of the left main bronchus, producing a stripe of density (left retrobronchial stripe) visible using computed tomography. Thickening or nodularity of the stripe, resulting in separation of air in lung from air in the bronchial lumen often reflects tumor infiltration of the bronchial wall, or lymphadenopathy. Consolidation of the lower lobe can obliterate the stripe, but, because the pleural space does not extend posterior to the bronchial wall, pleural effusion generally will not.

Adolescent↗
PubMed1983

Interlobar pleural plaque mimicking a lung nodule in a patient with asbestos exposure.

Computed tomography (CT) is generally superior to plain chest radiographs in differentiating pleural and pulmonary parenchymal lesions. We report a patient with asbestos exposure who had a rare interlobar pleural plaque involving the major fissure. In this patient CT suggested the presence of a lung nodule but the lateral chest radiograph indicated the correct diagnosis.

Asbestos↗
PubMed1983

Computed tomography of the pulmonary hilum in patients with bronchogenic carcinoma.

In 30 patients with histologically proven bronchogenic carcinoma, computed tomographic (CT) scans of the pulmonary hila, plain radiographs, and medical records were reviewed. All had abnormal plain radiographs. The CT findings included (a) a local alteration in hilar contour; (b) thickening of the posterior wall of the right upper lobe bronchus, bronchus intermedius, or left main bronchus; and (c) narrowing, displacement, or obstruction of bronchi. In 24 patients having fiberoptic bronchoscopy, CT findings of bronchial abnormality correlated closely with bronchoscopic findings. In two patients, CT showed a bronchial abnormality invisible at bronchoscopy, leading to a positive biopsy. In one patient, a bronchial abnormality invisible at CT was visible at bronchoscopy and positive on biopsy.

Adult↗
PubMed1983

CT appearance of bronchial carcinoid with recurrent pneumonia and hyperplastic hilar lymphadenopathy.

Computed tomography in a man with recurrent right lower lobe pneumonias showed an endobronchial mass associated with hilar lymph node enlargement. Because of this combination of findings, bronchogenic carcinoma with hilar node involvement was suggested as likely. Surgery revealed a carcinoid bronchial adenoma limited to the bronchus, with hyperplastic lymph node enlargement resulting from pneumonia. Care must be taken not to assume that hilar lymph node enlargement represents tumor, even when associated with an endobronchial lesion.

Bronchial Neoplasms↗
PubMed1983

Nuclear magnetic resonance imaging of the thorax.

Nuclear magnetic resonance (NMR) images of the thorax were obtained in ten normal volunteers, nine patients with advanced bronchogenic carcinoma, and three patients with benign thoracic abnormalities. In normal volunteers, mediastinal and hilar structures were seen with equal frequency on NMR images and computed tomographic scans. The hila were especially well displayed on spin-echo images. Spin-echo images showed mediastinal invasion by tumor, vascular and bronchial compression and invasion, and hilar and mediastinal adenopathy. Tumor and benign abnormalities could be separated from mediastinal and hilar fat because of their longer T1 times. Lung masses and nodules as small as 1.5 cm could be seen on the spin-echo images. NMR imaging shows promise for assessment of benign and malignant mediastinal, hilar, and lung abnormalities.

Adult↗
PubMed1983

Differentiating lung abscess and empyema: radiography and computed tomography.

Conventional chest radiographs and computed tomographic (CT) scans of 70 inflammatory thoracic lesions in 63 patients were reviewed and scored for diagnostic features. Pathologic confirmation of the final diagnosis was available in 42% (5/12) of lung abscesses and 31% (18/58) of empyemas. CT alone was sufficient to correctly diagnose 100% (70/70) of cases. Diagnostic information not available from conventional chest radiographs was obtained in 47% (33/70) of cases; in an additional 34% of patients, CT more accurately defined the extent of disease. The most reliable CT features for the differential diagnosis of lung abscess and empyema were wall characteristics, pleural separation, and lung compression. Conventional radiographic features such as size, shape, and the angle of the lesion with the chest wall were less helpful, though also best assessed by CT.

Diagnosis, Differential↗
PubMed1983

Complications following abdominal fascial closures using various nonabsorbable sutures.

With the use of the interrupted far-and-near fascial closure technique, four suture materials were compared: nylon, polypropylene and two brands of braided Dacron (Ethibond and Polydek). There were no wound dehiscences among the 96 patients studied. During the average follow-up period of 12 months, significantly more suture granulomas occurred with the braided Dacron than with the monofilament materials (p less than 0.05). Those that did occur with monofilament material occurred almost exclusively in thin patients.

Abdomen↗
PubMed1983

Advances in computed tomography of the thorax.

Because of its enhanced density resolution, cross-sectional format, and ability to simultaneously evaluate lung, mediastinum, and chest wall, computed tomography has largely replaced conventional techniques in several clinical situations. The author discusses the CT detection of diseases such as lung nodules, mediastinal masses, and hilar lesions; CT's use as a screening technique; and its replacement of angiography in the evaluation of intrathoracic vascular lesions.

Carcinoma, Bronchogenic↗
PubMed1982

Efficacy of antibiotic prophylaxis in high risk gastroduodenal operations.

A double-blind, prospective and randomized clinical trial of the efficacy of antibiotic prophylaxis in gastroduodenal operations was studied in 39 patients over an 18 month period. All patients had clinical features that placed them at high risk for the development of postoperative wound or intraabdominal sepsis. In the placebo group of 20 patients seven gastric-related infections developed, while 1 of the 19 patients who received perioperative cefamandole had one gastric-related infection (p less than 0.01). The responsible microorganisms were those that are normal components of the oral or intestinal microflora. Nongastric-related infections and deaths did not differ significantly in the two study groups. The results of this study confirm the efficacy of the use of short-term perioperative antibiotic prophylaxis in patients undergoing gastroduodenal surgery for bleeding duodenal or gastric ulcer, obstructing duodenal ulcer, gastric ulcer or malignancy.

Anti-Bacterial Agents↗