MR imaging in the evaluation and staging of lung cancer.
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Adrenal Gland Neoplasms↗
Biomedical subjects
W R Webb
Publications and source records attributed to W R Webb.
Postnatal changes in enzyme activities of rat myocardial adenine nucleotide catabolic pathway.
Three catabolic enzymes, 5'-nucleotidase (5'NT), adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP) and one anabolic enzyme, myokinase (MK) involved in adenine nucleotide (AN) metabolism were studied in myocardium from 4 to 105 day old rats. The specific enzyme activities (nmoles/min/mg protein) at day 4 were 35.3 for 5'NT, 28.4 for ADA, 43.3 for PNP, and 5 X 10(3) for MK. At day 7, 5'NT, activities rose to 450%; PNP and ADA 150%; and MK 120%; of the day 4 level. The activities of the three catabolic enzymes were elevated for one or two weeks then declined rapidly. By day 34, they were slightly above the adult values. MK activity displayed a different time course. It continued to increase slowly with age after the initial surge. Compared to the adult heart, the total activities of these catabolic enzymes in the one- to three-week-old heart were 30% to 220% higher. This transient elevation in AN catabolic enzyme activities may be related to active DNA synthesis and cell proliferation occurred in the rat myocardium during the same period.
5'-Nucleotidase↗
Management of airway trauma. II: Combined injuries of the trachea and esophagus.
Twenty-four consecutive patients with combined injuries of the trachea and esophagus were operated on at the Tulane University Hospital and the Charity Hospital of New Orleans between 1967 and 1983. Only 3 of the injuries resulted from blunt trauma, and 1 of these patients had a total transection of both the trachea and esophagus; the remaining injuries were due to penetrating trauma (20 gunshot wounds; 1 stab wound). The combined lesions involved the cervical region in 20 patients and the thoracic esophagus and trachea or bronchus in 4. All patients underwent bronchoscopy; in recent years all have had esophagoscopy, because our experience indicates that esophagrams, which patients also underwent, have a high rate (12.5%) of false negative results. Operative techniques included a two-layer closure of all esophageal injuries, closure of the trachea with non-absorbable monofilament suture, and transthoracic or cervical drainage. Muscle flaps were used for suture line reinforcement. Associated operative procedures included tracheostomy (5), laparotomy (4), vascular procedures (5), neurologic procedures (2), and closed-tube thoracostomy (6). Five patients (21%) died in the perioperative period, 4 of 20 with combined cervical injuries, and 1 of the 4 with combined thoracic injuries. Deaths resulted from missed injuries to the esophagus (2 patients), a missed tracheal injury (1), associated vascular injury (1), and associated thoracoabdominal injury (1). Two patients experienced cervical esophageal suture line leaks, both of which sealed with conservative therapy. Clinical follow-up showed good results in 90% of the patients who survived.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Plain radiography and computed tomography in the staging of bronchogenic carcinoma: a practical approach.
A determination of the anatomic extent of tumor is important in planning appropriate invasive diagnostic procedures and treatment in patients with bronchogenic carcinoma. In most situations, plain radiographs provide useful anatomic information, but CT is necessary for detailed evaluation. Although some plain film and CT findings strongly suggest that a tumor is unresectable, they are usually nonspecific, and biopsy correlation is necessary before the patient is denied an attempt at a surgical cure. Also, in the light of recent advances in the surgical treatment of lung cancer, some lesions formerly thought to be unresectable because of local or regional metastases are being effectively treated. Close communication between the radiologist and surgeon is necessary in the appropriate management of these patients.
Carcinoma, Bronchogenic↗
Chest wall after mastectomy. Part I. CT appearance of normal postoperative anatomy, postirradiation changes, and optimal scanning techniques.
The computed tomographic (CT) scans of patients with breast carcinoma treated by surgery with and without radiation therapy were reviewed and correlated with clinical status. The optimal techniques of patient examination and the post-therapy findings were analyzed. The brachial injection of intravenous contrast material produced significant artifacts that limited interpretation of the ipsilateral chest wall in all cases and did not give additional information. Scans obtained with the patients' arms placed at their sides resulted in more clearly interpretable scans, especially when arm weakness or lymphedema precluded symmetric elevation of the arms out of the CT gantry. Radiation therapy produced both acute and chronic changes with characteristic CT appearances. The postoperative anatomy varied markedly depending on the previous surgery. Careful clinical correlation with referring physicians was the key to proper scan evaluation.
Adult↗
Chest wall after mastectomy. Part II. CT appearance of tumor recurrence.
The postoperative computed tomography (CT) scans of 19 patients with breast cancer and suspected local or regional recurrence were reviewed. Recurrence was documented by percutaneous biopsy in 15 and by overwhelming clinical evidence in two. CT correctly identified the sites of recurrence in all 15 biopsy-proved cases. In two patients, suspected areas on CT scans proved to be residual pectoralis muscles. In most cases, the CT findings of recurrence to the skin, subcutaneous fat, pectoralis muscle, axilla, and brachial plexus can be differentiated from the postoperative and postirradiation anatomy.
Breast Neoplasms↗
Pulmonary lymphangitic spread of carcinoma: appearance on CT scans.
Chest computed tomography (CT), including high-resolution CT with thin (1.5-mm) sections was used to evaluate proved (pathologically or clinically) lymphangitic spread (LS) of tumor in 12 patients. These appearances were compared with thin-section scans obtained in 11 healthy subjects. Thin-section CT demonstrated findings consistent with thickening of the normal lung interstitium. In all patients, thin sections showed an increase in the number of peripheral lines (1-2 cm in length) that were diffuse in generalized disease and localized in focal disease. Normal peripheral arcades were not increased in number, but the limbs forming the arcades were thickened in all patients. A diffuse increase in linear and curvilinear structures (reticular pattern) was seen toward the center of the lung. Polygonal structures 1-2 cm in diameter were seen in seven patients with LS but not in healthy subjects. Fissures were thickened in nine patients. Selected 1.5-mm-thick CT sections are recommended through abnormal areas (seen at CT or on chest radiographs) or if these are normal at three levels (midapex, hilus, and 3 cm above the diaphragm) when scanning patients with tumors known to cause LS.
Adult↗
High-resolution CT of the lungs: an optimal approach.
The influences of kilovolt peak, milliamperage, reconstruction algorithm, targeting, and image magnification on thin-section (1.5-mm) computed tomography (CT) of the lung were studied in phantoms and patients. Retrospective targeted reconstruction (25-cm field of view) improved spatial resolution, while magnification did not. The bone reconstruction algorithm improved spatial resolution, compared with the standard algorithm, and in patients, bone algorithm images were considered superior to standard reconstructions. Although using the bone algorithm increases the visible image noise, increasing the kilovolt peak and the milliamperage can reduce this noise. However, in the patients studied, this reduction in noise was not usually judged as significant, except in the posterior, paravertebral part of the lung. An optimal technique for CT of the lung parenchyma should include thin-collimation, targeted scans reconstructed with a high-spatial-frequency algorithm and, in some patients, increased kilovolt peak or milliamperage.
Bone and Bones↗
Cine CT in obstructive sleep apnea.
The upper airway was evaluated in eight patients with obstructive sleep apnea by using a rapid sequential CT scanner (Imatron C-100). Four patients also had simultaneous polysomnograms to determine the onset of sleep and apnea. The upper airway was scanned while the patient was awake (eight patients), asleep (four patients), and asleep and apneic (eight patients). Measurements of the cross-sectional area of the upper airway were correlated with the findings on sleep studies in four patients. During the awake state the airway was narrowed and showed increased collapsibility in all eight patients. Five of the eight patients had cross-sectional areas of less than or equal to 4 mm2 at one or more sites at some time during the respiratory cycle while awake. During apnea all patients had obstruction at the uvula and oropharynx, but the length of the obstruction varied from one patient to another. In three of the eight patients the obstruction extended inferiorly to the hypopharynx. Cine CT can be used to objectively evaluate patients with sleep apnea and may demonstrate the need to modify surgical treatment.
Adult↗
Obesity: is it really a risk factor in thrombophlebitis?
Obesity is assumed to be a risk factor in the occurrence of thrombophlebitis. We studied 168 consecutive patients retrospectively; 33 were men and 135 women, with an average age of 34 (range 27 to 41) years. All patients had a gastric bypass because of obesity, with a minimum of 100 lb over normal weight. The mean weight was 279.2 lb (range 191 to 500). Only three patients had a history of deep vein thrombophlebitis, with no thromboembolism. Eighty-four of the patients were studied preoperatively by noninvasive means (Doppler, impedance plethysmography [IPG], phleborheography [PRG]); 12 had evidence of old disease, and two had a history of treated deep vein thrombophlebitis. No patient had prophylactic therapy. The incidence of clinical deep vein thrombophlebitis was zero; noninvasive evaluation in 64 patients demonstrated no abnormality. Postoperative thromboembolism, which occurred in three of 168 (1.8%) patients, was confirmed by ventilation-perfusion scan and pulmonary angiogram. The mortality from thromboembolism was less than 1% (1/168 patients). Extreme obesity may not necessarily constitute a major risk factor in the occurrence of postoperative deep vein thrombophlebitis and thromboembolism. Prophylactic medications and therapy may add inappropriate risk, undue cost, and unnecessary discomfort, and must be weighed against a mortality of less than 1%.
Adult↗
Recurrent hemoptysis treated by bronchial artery embolization.
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Adult↗
Choledochoscopy in prevention of retained common bile duct stones.
More than 150,000 patients undergo exploration of the common bile duct each year in the United States, and approximately 10 per cent of these patients are later found to have retained common bile duct stones. The usual recommended procedure to decrease the incidence of retained calculi is a more complete exploration of the common duct at time of initial operation. It is thought that the incidence of retained common bile duct stones can be decreased and almost eliminated with proper use of the flexible choledochoscope following intraoperative cystic duct cholangiogram. The technical aspects of choledochoscopy are reviewed and experience with its use in 102 cases between July 1978 and October 1985 is reported. There were no residual stones in the span of the study using the flexible choledochoscope as a routine procedure in common bile duct exploration.
Endoscopes↗
Magnetic resonance imaging of the hila and mediastinum.
In the diagnosis of chest diseases, MR imaging has been shown to be most helpful in the evaluation of hilar and mediastinal lesions. The detection of intrathoracic abnormalities is technique-dependent, and imaging with both short and long repetition and echo times is necessary. ECG gating and sagittal or coronal images supplement transaxial scans in some patients. MR allows the diagnosis of mediastinal vascular lesions and the differentiation of mediastinal mass and vessel without contrast agents. It provides diagnostic information quite similar to that of CT in patients with mediastinal mass, but spatial resolution is somewhat poorer. In patients with hilar mass, MR is superior to CT in identifying the mass and distinguishing it from normal structures.
Carcinoma, Bronchogenic↗
Postgraduate surgical flexible endoscopic education.
Postgraduate surgical education of residents in flexible gastrointestinal endoscopy is mandated by the American Board of Surgery. In that context, a retrospective analysis was performed of the general medical and endoscopic records of patients who experienced diagnostic and therapeutic flexible endoscopy during an 18-month period at the University of South Alabama Medical Center by surgical residents under the supervision of attending surgical endoscopists. That analysis revealed these procedures to be safe (diagnostic and therapeutic flexible endoscopy: morbidity incidence 0.4% and 2.2%, mortality incidence 0.2% and 1.1%, respectively), accurate (100%), and therapeutically beneficial (19% of the flexible endoscopic procedures were performed with therapeutic intent). Review of cumulative resident case profiles revealed that during the course of their clinical education (5 years), each resident performed approximately 400-500 endoscopic procedures, functioning successively as first assistant, primary endoscopist, and teaching assistant. The authors contend that: supervision by surgical endoscopists ensures safety and efficacy of the procedures during the education of postgraduate surgical residents; the surgical milieu--integration of endoscopic, surgical anatomic, and histopathologic data--provides the most effective educational format to acquire the skills necessary to achieve a high degree of accuracy associated with these endoscopic procedures; and therapeutic flexible endoscopy obviated the necessity for more invasive surgical procedures in approximately one-fifth of this patient population.
Adolescent↗
Normal thymus: assessment with MR and CT.
The magnetic resonance (MR) characteristics of the normal thymus in 18 patients were compared with computed tomographic (CT) findings in 13 of the 18. Patients ranged in age from 5 to 77 years. The thymus was visible in all patients and differed from subcutaneous fat in hydrogen density; the average thymus to fat hydrogen density ratio was 0.60. Although the T1 relaxation times of the thymus (mean = 703 msec) were much longer than those of fat (mean = 287 msec) in patients under 30 years of age, this difference decreased with age. The T2 relaxation times of the thymus were similar to those of fat and did not change with age. The thymus appeared thicker on MR images than on CT scans in patients older than 20 years. MR may be better than CT in distinguishing between thymus replaced by fat and mediastinal fat.
Adolescent↗
Normal and occluded mediastinal veins: MR imaging.
The potential of magnetic resonance (MR) imaging to demonstrate the mediastinal veins was evaluated retrospectively in 25 patients with no evidence of a venous abnormality, 28 patients who had narrowing or occlusion of a mediastinal vein, and two patients who had a venous anomaly. In patients with venous occlusion, the MR images graphically demonstrated the sites and extent. MR images also demonstrated slow flow within venous structures proximal to the obstruction. Generally, venous collaterals in the mediastinum and chest wall were better seen with contrast material-enhanced computed tomography scans. The marked contrast on MR images between the signal void of normal vascular structures, the moderate signal intensity of tumor, and the high signal intensity of a thrombus or slowly flowing blood allows ready detection of venous occlusion and may suggest the nature of the occlusion.
Adolescent↗
Fibrosing alveolitis: CT-pathologic correlation.
Computed tomography (CT) was performed within 10 days of open lung biopsy in nine patients with fibrosing alveolitis. One-centimeter collimation contiguous scans through the chest were obtained in all patients. Additional 1.5-mm collimation scans were obtained in the area in which lung biopsy was later performed in six patients. In seven patients, CT demonstrated patchy involvement of the lung parenchyma, areas with a reticular pattern being intermingled with areas of normal lung. The reticular pattern was associated with cystic spaces 2-4 mm in diameter and was more severe in the lung periphery. Histologically, the reticular pattern corresponded to areas of irregular fibrosis. One patient had diffuse honeycombing (2-20-mm cysts), and one had honeycombing only in the lung periphery. In all patients, CT clearly defined the architectural changes seen on open lung biopsy. These changes were much better seen on the 1.5-mm than on the 10-mm collimation scans. CT may be helpful in determining the pattern and distribution of lung involvement in patients with fibrosing alveolitis and in guiding the surgeon to the most appropriate area(s) for biopsy.
Adult↗
MRI of pulmonary airspace disease: experimental model and preliminary clinical results.
To evaluate the potential of MRI for differentiating the various causes of pulmonary consolidation, 16 patients with known airspace diseases were imaged, and T1 and T2 values were determined. Substantial overlap was encountered between different diagnostic groups of T1 and T2 mapping, although alveolar proteinosis was notable for its low T1 value. In addition, a gelatin phantom simulating consolidation with varying degrees of residual aeration was constructed and tested, demonstrating that the degree of aeration did not influence the T1 and T2 values measured.
Diagnosis, Differential↗