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Biomedical subjects

L Ketai

Publications and source records attributed to L Ketai.

17 recordsLinked to original sources
PubMed2001

Thin-section CT evidence of bronchial thickening in children with stable asthma: bronchoconstriction or airway remodeling?

RATIONALE AND OBJECTIVES: The authors performed this study to determine if bronchial wall thickening is present in children with moderate to severe asthma during periods free from clinical bronchoconstriction. MATERIALS AND METHODS: The authors obtained low (radiation) dose thin-section computed tomographic (CT) scans in each of 18 control subjects and 21 children with moderately severe but stable asthma. Spirometry was performed on all subjects at the time of CT scanning. Bronchial wall thickness and bronchial wall area were measured, and the percentage wall area (bronchial wall area divided by bronchial cross-sectional area) was calculated. The authors performed best-fit regression analysis of wall thickness and percentage wall area versus bronchial diameter and qualitative analysis of images for bronchial wall thickening. RESULTS: In asthmatic patients, the mean percentage of the predicted forced expiratory volume in 1 second was 0.88 +/- 0.09. The best fit regression line that demonstrated the relationship between wall thickness and bronchial diameter for patients with asthma differed significantly from that for control subjects (P < .005). The regression line that demonstrated the relationship between the percentage wall area and bronchial diameter for patients with asthma differed from that of the control subjects when bronchial wall thickness measurements were used to calculate the percentage wall area (P < .05). Results of qualitative analysis also showed significantly more bronchial wall thickening in asthmatic patients than in control subjects (P < .001). CONCLUSION: Bronchial wall thickening detected at thin-section CT in children with moderately severe asthma cannot be attributed solely to bronchoconstriction and may represent airway inflammation or remodeling.

Adolescent↗
PubMed2001

Potential uses of computed tomography-SPECT and computed tomography-coincidence fusion images of the chest.

The ability to fuse (or merge) data sets from SPECT and coincidence nuclear medicine scans with computed tomographic images combines physiologic information from the former method with the superior anatomic resolution of the latter technique. In many cases, this allows more definitive diagnosis than can be obtained by simple visual comparison of nuclear medicine images and conventional cross-sectional imaging. The technique may be used in the staging and follow-up of lung carcinoma, pulmonary carcinoid, and lymphoma. It may also aid in the interpretation of perfusion defects in Tc-99m MAA lung scanning, aid in the interpretation of ground-glass opacity in selected cases of chest high-resolution computed tomography, and aid in the diagnosis of some mediastinal masses (e.g., intrathoracic goiters). In this nuclear medicine atlas, the method used to create fusion images in the chest is described, and examples of fusion imaging with radiopharmaceuticals are given that may be of clinical use in chest disease.

Humans↗
PubMed2000

Is the stat Gram stain helpful during percutaneous image-guided fluid drainage?

RATIONALE AND OBJECTIVES: The purpose of this study was to use logistic regression to analyze both Gram stain results and other clinical information to create a decision rule capable of predicting which abdominal or pelvic fluid collections would later prove to be infected and therefore require catheter drainage. MATERIALS AND METHODS: The authors retrospectively collected Gram stain results and clinical data (postoperative status and antibiotic use) regarding 124 abdominal or pelvic fluid drainage procedures performed between 1991 and 1996. They then analyzed these data by using logistic regression to create an equation that predicted the presence of fluid infection. Finally, they validated this equation by applying it to 39 abdominal or pelvic fluid drainage procedures performed in 1997. RESULTS: The resulting equation predicted that a fluid collection was likely to be infected if any of the following were present: Gram stain positive for bacteria, Gram stain showing moderate or many white blood cells, and purulent fluid at visual inspection. For the initial data set, the sensitivity of the decision rule was 91%, the specificity was 54%, and the overall accuracy was 77%. For the 1997 data set, the sensitivity of the decision rule was 88%, the specificity was 50%, and the accuracy was 77%. CONCLUSION: When combined with clinical information, Gram stain results are sensitive but nonspecific in the detection of abdominal or pelvic fluid infection. Use of the decision rule could prevent unnecessary catheter placement in a minority of patients with abdominal or pelvic fluid collections.

Abdominal Abscess↗
PubMed2000

Nonaortic mediastinal injuries from blunt chest trauma.

In addition to traumatic aortic injuries (TAI), blunt chest trauma may damage other structures in the mediastinum, including the tracheobronchial tree, the heart and pericardium, and rarely the esophagus. Tracheobronchial injuries may be difficult to separate radiographically from accompanying parenchymal lung injuries. Experience with diagnosis by computed tomography (CT) is still limited. Cardiac injuries often require emergent surgery before extensive imaging can be done. Some patients, usually those with chamber ruptures of the right heart, survive long enough to receive a chest CT, at which time hemopericardium can be detected. Upper esophageal injuries may occur in conjunction with lower cervical or upper thoracic spine injures. Distal esophageal injuries are rarely caused by blunt trauma.

Angiography↗
PubMed2000

Small nodules detected on chest radiography: does size predict calcification?

STUDY OBJECTIVES: To determine whether the likelihood of lung nodule calcification can be predicted from nodule size as measured on a chest radiograph (CXR). DESIGN: Retrospective review of CXRs of patients with lung nodules < or =1 cm in size detected on CT scanning. CT images were used to identify calcifications and to provide spatial localization for readers to visualize nodules on a CXR and to measure their size. A subset of these nodules then was reexamined by different readers who did not view the CT scans SETTING: Two university hospitals (Albuquerque, NM; Dallas, TX) and a US Air Force/Veterans Administration medical center (Albuquerque, NM). PATIENTS: Two hundred thirty-six nodules in 185 patients RESULTS: One half of the nodules (118) seen on CT scans could not be located on CXR, of which 8 (7%) were calcified. The prevalence of calcifications in the other 118 nodules visualized on CXRs was much higher (71 of 118 nodules [60%]; p<0.005). Among the nodules visualized on CXRs, those < 7 mm in diameter (44 of 57 nodules [77%]) were more likely to be calcified than those > or = 7 mm in diameter (27 of 61 nodules [44%]; p<0.005). Radiographs of 42 of the smallest nodules visualized on CXRs by the initial readers later were examined prospectively by different readers who did not have access to the CT images. Thirty of 33 of the calcified nodules (91%) but only 3 of 9 of the noncalcified nodules (33%) were detected (p<0.005). These readers also recorded 40 additional small nodules that were not seen on CT scans, which were considered to be false-positives. CONCLUSIONS: Nodules detected on CXRs that measure <7 mm in size are likely to be calcified or to represent a false-positive finding.

Calcinosis↗
PubMed1999

Esophageal rupture after regional anesthesia: report of two cases.

Esophageal perforation after anesthesia is rare. It is usually secondary to esophageal instrumentation. Only one case of barogenic rupture after regional anesthesia has been reported. We report two additional cases and present possible mechanisms for this unusual entity. Neither patient had anatomic abnormalities by history or preoperative endoscopy. However, both patients and the previously reported patient had esophageal dysmotility resulting from advanced age, alcoholism, intraoperative medications, and preexisting disease. Each patient experienced at least one episode of emesis with subsequent perforation of the distal one third of the esophagus. The previously reported patient died; both of our patients underwent successful surgical repair and are alive 2 years later. Intraoperative or postoperative emesis in patients with esophageal dysmotility appears to be the principal factor causing esophageal rupture after regional anesthesia. Prevention of nausea and vomiting and recognition of this high-risk population may minimize this complication in the future.

Aged↗
PubMed1999

Primary mediastinal malignancies: findings in 219 patients.

The purpose of this study was to determine the demographics, histology, methods of treatment, and survival in primary mediastinal malignancies. We did a retrospective review of the statewide New Mexico Tumor Registry for all malignant tumors treated between January 1, 1973 and December 31, 1995. Benign tumors and cysts of the mediastinum were excluded. Two hundred nineteen patients were identified from a total of 110,284 patients with primary malignancies: 55% of tumors were lymphomas, 16% malignant germ cell tumors, 14% malignant thymomas, 5% sarcomas, 3% malignant neurogenic tumors, and 7% other tumors. There were significant differences in gender between histologies (P < 0.001). Ninety-four percent of germ cell tumors occurred in males, 66% of neurogenic tumors were in females; other tumors occurred in males in 58% of cases. There were also significant differences in ages by histology (P < 0.001). Neurogenic tumors were most common in the first decade, lymphomas and germ cell tumors in the second to fourth decades, and lymphomas and thymomas in patients in their fifth decades and beyond. Stage at presentation (P = 0.001) and treatment (P < 0.001) also differed significantly between histologic groups. Five-year survival was 54% for lymphomas, 51% for malignant germ cell tumors, 49% for malignant thymomas, 33% for sarcomas, 56% for neurogenic tumors, and 51% overall. These survival rates were not statistically different (P > 0.50). Lymphomas, malignant germ cell tumors, and thymomas were the most frequently encountered malignant primary mediastinal neoplasms in this contemporary series of patients. Demographics, stage at presentation, and treatment modality varied significantly by histology. Despite these differences, overall five-year survival was not statistically different.

Adult↗
PubMed1998

Pulmonary delivery of nanoparticles of insoluble, iodinated CT X-ray contrast agents to lung draining lymph nodes in dogs.

Lung cancer continues to be a leading cause of death around the world. Staging of this disease is critically dependent upon the involvement or noninvolvement of the lymph nodes which drain the region of lung containing the lesion/tumor. Palpation, unenhanced CT, and lymph node excision (i.e., mediastinectomy) are currently used to ascertain the status of these regional draining lymph nodes. The work reported herein details the first efforts toward the pulmonary instillation of iodinated nanoparticles for contrast-enhanced CT of lung draining lymph nodes. The data reflect the impact of dose, time post instillation, and formulation (surfactant) upon the observed CT enhancement of the tracheobronchial lymph nodes of beagle dogs. In addition, initial safety is discussed with both macroscopic and microscopic observations. The results indicate that pulmonary instillation of small volumes of iodinated nanoparticles could be successfully used to aid staging of lung cancer by CT imaging.

Administration, Inhalation↗
PubMed1998

Mediastinitis without antecedent surgery.

The study evaluates the results of aggressive surgical treatment for mediastinitis without antecedent surgery, after retrospectively reviewing all patients with mediastinitis, excluding patients with prior cardiac, esophageal or mediastinal operations, treated between June 1, 1992 and August 1, 1996. 8 patients were treated. 7 were male, mean age was 58 years. The etiology was Boerhaave's syndrome in 4, iatrogenic injury in 2 and descending necrotizing mediastinitis in 2 patients. The mean number of operations was 2.5. The initial operation was through thoracotomy in 5 patients and sternotomy in 2 patients. 4 patients underwent neck drainage, 1 as primary treatment and 3 combined with transthoracic drainage. 1 patient received laparotomy. Mean hospitalization was 52 days (excluding 1 death). Complications included mechanical ventilation greater than 48 hours in 7 patients, 2 or more operations in 5 patients, multisystem organ failure in 5 patients and other complications in 6 patients. Death occurred in one patients. Mediastinitis without antecedent surgery is associated with significant morbidity, however, with aggressive surgical drainage 87% of patients survived.

Adult↗
PubMed1997

Detection of pulmonary emboli and associated right heart dysfunction by combining ventilation perfusion lung scanning and xenon ventriculography.

PURPOSE: The authors sought to determine if the right ventricular ejection fraction (RVEF), as measured by xenon ventriculography, is depressed in patients with pulmonary emboli. The authors also sought to correlate any decrement in RVEF with the extent of lung perfusion defects. MATERIALS AND METHODS: The authors identified all patients who had lung ventilation-perfusion (V/Q) scans between January 1994 and December 1996, that were interpreted as high probability for pulmonary embolism. From these patients, the authors selected those who had undergone concurrent xenon ventriculography (XV) (n = 23), and then reprocessed the initial ventriculography data for confirmation. The authors also reviewed original V/Q scans, chest radiographs, and clinical data. A control group was drawn from patients with normal V/Q scans who had undergone XV. RESULTS: Fifteen patients (65%) with high probability V/Q scans had an abnormally low RVEF (< .32). Patients with high probability V/Q scans also had a significantly lower mean RVEF (0.28 +/- .08) than patients with normal V/Q scans (.39 +/- .08 SD). The degree of RVEF decline correlated poorly with the number of segmental perfusion defects (r = -.39). CONCLUSIONS: RVEF is often depressed in patients with high probability V/Q scans. XV can identify these patients, while routine lung V/Q scans cannot.

Adult↗
PubMed1995

Air embolus complicating transthoracic percutaneous needle biopsy.

Transthoracic percutaneous needle biopsy has become popular for evaluation of pulmonary nodules. However, it is a procedure with morbidity and mortality that is not negligible. In this article, we report massive air embolus complicating needle biopsy in a patient with amyloidosis. A negative biopsy does not exclude malignancy, and if surgical excision will be performed regardless of the result, preoperative assessment using this technique may not be necessary.

Aorta, Thoracic↗
PubMed1988

Reversibility of diaphragm fatigue by mechanical hyperperfusion.

Diaphragm function is thought to depend on the balance between diaphragm blood flow and metabolic demand. If blood flow is inadequate, fatigue should ensue. Likewise, in the presence of fatigue, function should improve when blood flow is increased. To test this hypothesis, we evaluated the effect of increasing blood flow to the fatigued diaphragm. Studies were performed on anesthetized, mechanically ventilated dogs in which strips of costal diaphragm were developed in situ. Strip tension was measured with an isometric tension transducer. The inferior phrenic artery supplying the strip was cannulated and pump perfused at a pressure of 92 +/- 3 mm Hg; phrenic artery flow and pressure were continuously monitored with in-line doppler flow probes and pressure transducers, respectively. Fatigue was produced by electrically stimulating strips to contract 15 times/min (initial tension 80% of maximum, duty cycle 50%). Rhythmic contraction resulted in a downward shift in the diaphragm force-frequency relationship in all strips. In eight strips, stepwise increments in phrenic artery perfusion pressure to 161 +/- 8 and 281 +/- 17 mm Hg were produced by increasing pump speed at 6 and 8 min into rhythmic stimulation; in four strips, phrenic artery perfusion pressure was increased to 152 +/- 20 and 257 +/- 32 mm Hg at 20 and 25 min into rhythmic stimulation, respectively. Each increase in phrenic artery pressure resulted in increases in phrenic artery flow and diaphragm tension and produced an upshift in the diaphragm force-frequency relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗