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Biomedical subjects

J L Westcott

Publications and source records attributed to J L Westcott.

At least 19 recordsLinked to original sources
PubMed2000

Transthoracic hilar and mediastinal biopsy.

TNB of the mediastinum is an accurate, safe, and cost-effective diagnostic tool for the evaluation of mediastinal masses and lymphadenopathy. The technique is most useful in the staging of carcinoma, where it serves as a less expensive and minimally invasive alternative to mediastinoscopy for establishing unresectability. With recent advances in immunohistochemical and core biopsy techniques, TNB has become more accurate for establishing the initial diagnosis of lymphoma and for confirming recurrent disease. Core-needle biopsy has improved the accuracy of TNB and is particularly useful when fine-needle aspiration fails to yield a specific diagnosis, or when lymphoma or a noncarcinomatous lesion is suspected.

Biopsy, Needle↗
PubMed1999

Pneumothorax and dependent versus nondependent patient position after needle biopsy of the lung.

PURPOSE: To test the hypothesis that placing the patient in a position with the puncture site dependent (down) after transthoracic needle biopsy reduces the incidences of pneumothorax and of pneumothorax that requires chest tube placement. MATERIALS AND METHODS: Four hundred twenty-three needle biopsies of the lung were performed in 390 patients from October 1991 to August 1994 with computed tomographic guidance, fluoroscopic guidance, or both. Two hundred forty-two biopsies were performed from the posterior approach, 166 from the anterior approach, and 15 from the lateral approach. The patients were assigned on an alternating basis to either the puncture-site-dependent recumbent position (210 biopsies) or the puncture-site-nondependent recumbent position (213 biopsies) for at least 1 1/2 hours after biopsy. RESULTS: No significant differences were found in either the incidence of pneumothorax (dependent position, 62 of 210 biopsies [30%], vs nondependent position, 57 of 213 biopsies [27%]; P = .60) or the incidence of pneumothorax that required chest tube placement (dependent position, 10 of 210 biopsies [5%], vs nondependent position, six of 213 biopsies [3%]; P = .43). CONCLUSION: The results suggest that the puncture-site-down postbiopsy position may not affect either the incidence of postbiopsy pneumothorax or the incidence of pneumothorax that requires chest tube placement.

Adult↗
PubMed1997

Transthoracic hilar and mediastinal biopsy.

Transthoracic needle biopsy (TNB) of the mediastinum is an accurate, safe, and cost-effective diagnostic tool for the evaluation of mediastinal masses and lymphadenopathy. The technique is most useful in the staging of carcinoma, where it serves as a less expensive and minimally invasive alternative to mediastinoscopy for establishing unresectability. With recent advances in immunohistochemical and core-biopsy techniques, TNB has become more accurate for establishing the initial diagnosis of lymphoma and for confirming recurrent disease. Core-needle biopsy has improved the accuracy of TNB and is particularly useful when fine-needle aspiration fails to yield a specific diagnosis, or when lymphoma or a noncarcinomatous lesion is suspected.

Biopsy, Needle↗
PubMed1997

Transthoracic needle biopsy of small pulmonary nodules.

PURPOSE: To evaluate the diagnostic accuracy, complications, and usefulness of transthoracic needle biopsy of small pulmonary nodules. MATERIALS AND METHODS: Between January 1993 and January 1995, 302 patients underwent transthoracic needle biopsy of pulmonary lesions. Sixty-four lesions (in 62 patients) represented small nodules, defined as lesions of 15 mm or less maximum diameter. A total of 75 biopsies were performed in the 64 lesions. Approximately 90% of the biopsies were performed with computed tomographic guidance. RESULTS: There were 21 benign lesions and 43 cancers (36 primary, seven metastatic). Transthoracic needle biopsy findings were positive for cancer in 40 cases. In all three false-negative lesions, only one biopsy was performed. There were 21 true-negative results and no false-positive results. Positive and negative predictive values were 100% and 88%, respectively. Pneumothorax occurred in 20 (27%) of 75 biopsies, but chest tube placement was necessary in only three cases (4%). Surgery or thoracoscopy was avoided in 31 patients: 17 of 20 patients with benign disease, seven patients with metastatic disease, and seven patients with inoperable lung cancer. CONCLUSION: Transthoracic needle biopsy of small pulmonary nodules can produce diagnostic yields comparable with published results of transthoracic needle biopsy of larger lesions.

Adult↗
PubMed1996

Transthoracic needle biopsy of mediastinal lymph nodes for staging lung and other cancers.

PURPOSE: To determine the usefulness of transthoracic needle biopsy of mediastinal lymphadenopathy for staging suspected lung and other cancers. MATERIALS AND METHODS: Transthoracic needle biopsy of the hilum or mediastinum was performed in 111 patients with suspected neoplasms. Most biopsy procedures were performed with computed tomographic guidance on an outpatient basis. Forty-eight adult patients had enlarged lymph nodes (defined as < or = 30 mm in the long axis and > or = 10 mm in the short axis). Sixty-three lesions larger than 30 mm were arbitrarily considered to be masses and were excluded. RESULTS: Carcinoma was diagnosed in 40 patients. Four patients had true-negative and one patient had false-negative results. Sensitivity for carcinoma was therefore 98% (40 of 41). One patient with a negative biopsy result did not have surgical confirmation and was excluded from analysis. Lymphoma was excluded from analysis. Lymphoma was diagnosed in two patients (positive in one and suspicious in one). Pneumothorax occurred in 19 (34%) of 56 biopsy procedures. Chest tube treatment was required in eight (14%). CONCLUSION: Transthoracic needle biopsy of mediastinal lymphadenopathy is a safe, accurate diagnostic staging procedure. It can frequently be used as an alternative to mediastinoscopy in patients with lymphadenopathy.

Adult↗
PubMed1996

Barotrauma.

Barotrauma remains a significant complication of mechanical ventilation, particularly in ARDS. A number of alternative techniques for mechanical ventilation are being investigated with the purpose of minimizing ventilator-related lung injury and air leak phenomena while maintaining adequate oxygenation. Among them pressure-controlled inverse-ratio ventilation and extracorporeal carbon dioxide removal have not resulted in a definite reduction of barotrauma thus far. The radiologist plays an important role in the early recognition of barotrauma and may assist in the treatment of its sequelae.

Barotrauma↗
PubMed1995

Peripheral bronchopleural fistula: CT evaluation in 20 patients with pneumonia, empyema, or postoperative air leak.

PURPOSE: To assess the usefulness of standard and thin-section computed tomography (CT) in the examination of patients with possible bronchopleural fistulas (BPFs). MATERIALS AND METHODS: Twenty patients with known or suspected BPFs underwent CT. Twelve had pleural air and fluid collections; eight had air leaks. Fourteen patients also underwent thin-section CT. RESULTS: The BPF or its probable cause was visualized in all patients with air and fluid collections and in two of the patients with air leaks. BPFs due to bronchiectasis, necrotizing pneumonia, or alveolar cell carcinoma were identified in 10 patients. In four others, bronchiectasis was seen but the actual communication was not. In seven patients with postoperative air leaks, standard or thin-section CT demonstrated the air-leak source in only one. Thin-section CT was superior to standard CT in six of eight patients in whom the BPF or its probable cause was visible. CONCLUSION: Standard and thin-section CT are useful in the diagnosis and management of peripheral BPFs.

Adolescent↗
PubMed1995

Left pulmonic recess of the pericardium: findings at CT and MR imaging.

PURPOSE: To assess the prevalence and appearance of fluid in the left pulmonic pericardial recess (LPR) on computed tomographic (CT) scans and magnetic resonance (MR) images of patients without pericardial effusion. MATERIALS AND METHODS: Eighty consecutive contrast material-enhanced CT scans and 50 consecutive MR images of the thorax were evaluated for the presence of fluid in the LPR, transverse sinus, and superior pericardial recess. RESULTS: Fluid was identified in the LPR in approximately 25% of patients without pericardial effusion (14 of 62 CT scans, eight of 30 MR images). At MR imaging, the LPR and other recesses appeared as a signal void on spin-echo images but demonstrated high signal intensity on gradient-echo flow-sensitive images. CONCLUSION: Recognition that fluid in the LPR can be a normal finding in patients without pericardial effusion should help avert misdiagnoses of lymphadenopathy.

Diagnosis, Differential↗
PubMed1994

Size of the zinc pools that exchange rapidly with plasma zinc in humans: alternative techniques for measuring and relation to dietary zinc intake.

A relatively simple technique was used to estimate the size of the combined pools of zinc with which plasma zinc exchanges within 2 d (EZP). EZP size was determined from the amount of isotope introduced into the plasma and the coefficient of the simple exponential decay function fitting enrichment data between d 3 and 9 after isotope administration. Using data from 11 healthy adults, comparisons were made of EZP size estimations using oral and intravenous isotopes (r = 0.93 using urine) and urine and plasma enrichment (r = 0.85 for intravenous). EZP size estimations from urine and plasma enrichment following intravenous isotope administration were 2.35 +/- 0.84 and 2.83 +/- 0.86 mmol, respectively (mean +/- SD, P < 0.01). EZP size correlated with habitual dietary zinc intake (partial r = 0.74, P < 0.02). Cumulative declines in EZP size in two healthy adults after 3 wk of consuming a moderately zinc-restricted diet followed by 1 wk of severe zinc restriction were 26 and 32%. These results indicated that EZP size is dependent on dietary intake. We conclude that this technique is adequate to demonstrate EZP differences that are of nutritional and physiological interest. EZP size estimates can be obtained using orally or intravenously administered isotope and using plasma or urine enrichment data.

Administration, Oral↗
PubMed1994

Daily variation in plasma zinc concentrations in women fed meals at six-hour intervals.

Ten pre-menopausal women participated in two studies to measure the daily variations in plasma zinc when meals were fed at 6-h intervals and to determine if the response was related to shifts in serum insulin, glucose, calcium, or phosphorus concentrations. In Study 1, identical meals were fed at 6-h intervals for 2 d, and blood was sampled 8 times between each meal. In Study 2, the women fasted from 1800 h on d 1 to noon the next day, and blood was sampled hourly from 0700-1200 on d 2. The postprandial plasma zinc response was similar following all four meals and accounted for 50% of the total within subject variation in plasma zinc. A small (2-6%) increase occurred within the first 60 min; then plasma zinc declined to a low point at 4 h after the meal. This characteristic pattern was not observed during the fasting study. Serum phosphorus varied consistently after each meal with a net efflux from circulation that preceded an efflux of zinc by 2 h. The postprandial response of serum glucose and insulin were related to the postprandial plasma zinc response measured 6 h earlier; the variables were not correlated at concurrent time points. The data show that food intake is a determinant of the daily variations in plasma zinc. The net efflux of zinc from circulation following meals may reflect hepatic zinc uptake in association with an increase in postprandial liver metabolism.

Adult↗
PubMed1994

The practice of chest radiology in departments with residency programs.

OBJECTIVES: The authors assessed to what extent radiology teaching programs employed dedicated chest radiologists and their functions. METHODS: Information regarding the clinical, teaching, and research role of the chest radiologist was available from responses to a survey of radiology departments with residency training programs in the United States and Canada. Emphasis was placed on the role of chest subspecialists, "dedicated chest radiologists" (DCRs), who spent at least two thirds of their clinical time interpreting and directing chest-related imaging studies and procedures. RESULTS: Among the 171 residency programs that responded, 118 had DCRs. There were 262 full-time and 233 part-time DCR positions, of which 43 were not filled. Among departments with DCRs, 66% were medical school programs while the remaining 34% were independent or medical-school-affiliated programs; 30% were organized by organ system, 5% by technology, and 65% had a combination of both; and 78% had more than 12 residents. DCRs interpreted routine chest radiographs in 96%, critical care radiographs in 94%, chest computed tomography (CT) studies in 72%, and chest magnetic resonance imaging (MRI) studies in 44% of their departments. Departments without DCRs were usually smaller, 70% having 12 or fewer residents. Their designated chest radiologists interpreted all chest radiographs in 21%, all critical care radiographs in 19%, all chest CT studies in 13% and all chest MRI studies in 8% of these departments. CONCLUSIONS: Dedicated chest radiologists were more involved than non-DCRs in all aspects of chest imaging, teaching, and research including analysis of image quality and acquisition of new technology. The highest quality of chest radiology training, defined as programs in which the chest fellowship positions were filled in 1991, was found in departments in which DCRs interpreted all chest radiographs, all chest CT studies, and most MRI studies.

Canada↗
PubMed1993

Treatment of peripheral bronchopleural fistulas with endobronchial occlusion coils.

Persistent peripheral bronchopleural fistulas can be difficult to manage. Endoscopic plugging of involved bronchi has been accomplished in a number of ways. We have devised a method of permanently blocking small peripheral airways using Gianturco vascular occlusion coils placed endobronchially by modified angiographic techniques. This procedure has been applied in 5 cases of complicated parenchymal air leaks. Complete or substantial partial control was achieved in all cases. There were no complications.

Adult↗
PubMed1993

Influence of a meal and incremental doses of zinc on changes in zinc absorption.

The objective of this study was to determine the effect of increasing quantities of zinc, administered with and without a meal, on zinc absorption. Fractional absorption of incremental quantities of zinc in four normal adults was determined by measuring fecal excretion of unabsorbed isotope on 3 consecutive days by using three different stable isotopes of zinc (67Zn, 68Zn, and 70Zn). Isotopes were administered in the post-absorptive state and, on a subsequent occasion, with a standard zinc-free breakfast. In the postabsorptive state, fractional absorption was not affected by the quantity of zinc ingested until this exceeded 5 mg. When the zinc was administered with a meal, however, fractional absorption of 3 and 5 mg was less than for 1 mg. These results are compatible with the hypothesis that exogenous dietary zinc has to compete for absorption with endogenous zinc that has been secreted into the lumen of the gastrointestinal tract in response to a meal.

Absorption↗
PubMed1993

Effects of dietary zinc restriction on postprandial changes in plasma zinc.

The principal objective of this study was to determine the effect of a short period of severe dietary zinc restriction on both prebreakfast and postbreakfast plasma zinc concentrations. After an overnight fast, plasma zinc was measured in five normal adults before and at 30-min intervals for 6 h after a standard zinc-free test meal. This test was performed after a week on a zinc-adequate diet and repeated after a week of severe dietary zinc restriction. Postabsorptive premeal plasma zinc did not change after a week of severe dietary zinc restriction but the posttest meal decline was significantly greater and the maximum decline less variable (15-23%). It is concluded that postprandial plasma zinc is more sensitive than prebreakfast plasma zinc to dietary zinc depletion. Recent zinc intake is one factor that determines the magnitude of the postprandial net efflux of zinc from the plasma compartment.

Adolescent↗
PubMed1993

The role of transthoracic needle biopsy for the diagnosis and staging of lung cancer.

Percutaneous transthoracic needle biopsy (TNB) is a simple and safe procedure with high diagnostic accuracy for the diagnosis and staging of cancer in the lung, hilum, and mediastinum. The complication rate is low and consists primarily of pneumothorax, with only a small percentage of these requiring chest tube reexpansion. Major complications are rare. Computed tomographically guided biopsy is a powerful adjunct to fluoroscopic biopsy and expands the application of TNB to include most thoracic lesions. TNB is the initial diagnostic procedure of choice in peripheral lung lesions, suspected focal metastases, and most hilar and mediastinal masses. Its proper role in the diagnosis and staging of lung cancer requires the close collaboration of the radiologist, cytopathologist, and the patient's primary physician.

Biopsy, Needle↗
PubMed1991

Bronchiectasis.

Bronchiectasis is important because (1) it predisposes the patient to infection; (2) it may be accompanied by increased bronchial blood flow and hemoptysis; (3) when widespread, it may be associated with significant airway obstruction; and (4) when focal, it may simulate neoplasms and other diseases. The widespread use of computed tomography (CT) for evaluation of lung diseases has revealed that bronchiectasis is common--even in patients who do not have clinical or plain radiographic suspicion of bronchiectasis. The pathology, pathogenesis, and radiographic findings are presented herein.

Bronchiectasis↗