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Biomedical subjects

R D Tarver

Publications and source records attributed to R D Tarver.

At least 19 recordsLinked to original sources

Noninfectious and nonmalignant pulmonary disease in AIDS.

Infectious and malignant disease processes are responsible for most pulmonary abnormalities seen in patients with acquired immunodeficiency syndrome (AIDS). There are, however, a number of noninfectious and nonmalignant disorders that can involve the lungs of these individuals. Nonspecific interstitial pneumonitis and lymphocytic interstitial pneumonitis may mimic opportunistic infections both clinically and radiographically. Congestive cardiomyopathy may develop and result in pulmonary edema. Other disorders such as alveolar proteinosis and desquamative interstitial pneumonitis are also reported. Bronchoalveolar lavage, a diagnostic technique frequently employed in AIDS patients, may itself produce pulmonary opacities. Knowledge of these disorders may aid in the evaluation of AIDS patients for whom an infectious etiology for pulmonary abnormalities cannot be found.

Acquired Immunodeficiency Syndrome

Broncholithiasis: CT features in 15 patients.

Broncholithiasis is a disorder characterized by peribronchial calcific nodal disease that either erodes into an adjacent bronchus or distorts the bronchi. The key radiologic finding is a calcified endobronchial or peribronchial lymph node. To determine the CT findings of broncholithiasis, we retrospectively reviewed the chest radiographs and CT scans of 15 patients with proved broncholithiasis. Ten patients had endobronchial nodes as proved by bronchoscopy, surgery, or lithoptysis. Broncholiths were identified on bronchoscopy in only five cases. Five patients had peribronchial nodes with associated bronchial distortion. Collimation of the CT scans varied; 1.0-cm-, 0.6-cm-, and 0.5-cm-thick sections were obtained. Three patients had both 1.0-cm- and 0.5-cm-thick sections. The calcified lymph node was identified on CT in all 15 patients. CT correctly localized six of 10 endobronchial nodes and four of five peribronchial nodes. Findings due to bronchial obstruction also were seen on CT; atelectasis (n = 11), infiltration (n = 4), bronchiectasis (n = 4), and air trapping (n = 1). An associated soft-tissue mass was not seen in any case. Difficulty in determining the relationship between lymph node and bronchus is due to volume averaging, which can be decreased by scanning thinner sections. CT can suggest the diagnosis of broncholithiasis and is useful when bronchoscopy does not show a broncholith.

Adult

Distinguishing viable from infarcted myocardium after experimental ischemia and reperfusion by using nuclear magnetic resonance imaging.

Early reperfusion has the potential for salvaging ischemic myocardium at risk for infarction. To test the ability of nuclear magnetic resonance (NMR) imaging to differentiate between stunned and infarcted myocardium early after reperfusion, 16 mongrel dogs underwent transient occlusion of the left anterior descending artery or a diagonal branch for 30, 60 or 180 min followed by reperfusion. To identify the area at risk for infarction and to assess the extent of hypoperfusion and reperfusion, two-dimensional and contrast echocardiography were performed at baseline study, during coronary occlusion and at three separate times during reperfusion (before NMR imaging, immediately after NMR imaging and 12 to 14 h later). Wall thickening in the control and ischemic zones and the circumferential extent of abnormal wall motion were analyzed at each time point using short-axis echocardiograms. Nuclear magnetic resonance imaging at 1.5 tesla was performed 2 to 3.5 h (mean 2.7 +/- 0.5) after reperfusion. Short-axis, multislice spin-echo images (TE 26 and TE 60) were obtained. Signal intensity was measured in the control and ischemic areas and expressed as a percent difference compared with normal myocardium. All dogs demonstrated a significant decrease in wall thickening and abnormal wall motion before and after NMR imaging. Seven of the eight dogs with infarction had an area of increased signal intensity on TE 60 images. The mean percent difference in signal intensity compared with adjacent normal myocardium was 127 +/- 68% (p = 0.002). None of the eight dogs without infarction had a visually apparent change in signal intensity on TE 60 images (mean percent difference versus control area 13 +/- 11%), despite regional systolic dysfunction documented by echocardiography at the time of imaging. The area of increased signal intensity correlated with infarct size (r = 0.69), although overestimation by NMR imaging occurred. The area of increased signal intensity did not correlate with the extent of echocardiographic contrast defect during coronary occlusion (risk area). This study demonstrates that NMR imaging can be applied early after coronary reperfusion to assess the potential for recovery of dysfunctional myocardium. In addition, by using a TE 60 multislice spin-echo imaging sequence at 1.5 tesla, quantification of the extent of infarction also may be possible.

Animals

Pediatric digital chest imaging.

The Philips Computed Radiography system performs well with pediatric portable chest radiographs, handling the throughout of a busy intensive care service 24 hours a day. Images are excellent and routinely provide a conventional (unenhanced) image and an edge-enhanced image. Radiation dose is decreased by the lowered frequency of repeat examinations and the ability of the plates to respond to a much lower dose and still provide an adequate image. The high quality and uniform density of serial PCR portable radiographs greatly enhances diagnostic content of the films. Decreased resolution has not been a problem clinically. Image manipulation and electronic transfer to remote viewing stations appear to be helpful and are currently being evaluated further. The PCR system provides a marked improvement in pediatric portable chest radiology.

Child

Pleural cryptococcosis.

Pleural infection by Cryptococcus neoformans is uncommon and when present typically occurs in the immunocompromised host. We report two renal transplant patients who developed pleural cryptococcosis.

Adult

Traumatic rupture of the aorta. Indications for aortography.

The indications for thoracic aortography in the blunt chest trauma patient remain controversial. Clinical and radiographic findings in 102 patients seen at a Level I Trauma Center over a five-year period were reviewed to evaluate criteria predictive of major thoracic vascular injury. Five patients had positive aortograms. There was no significant correlation with Revised Trauma Score, symptoms, or associated thoracic injuries, although patients with aortic rupture did have a higher incidence of extrathoracic injuries (P less than 0.001). A blinded review of admitting chest radiographs for five major findings (widened mediastinum, aortic arch abnormalities, aortopulmonary window opacification, left apical capping, and right apical capping) revealed a significant difference between patients with and without aortic injury (0.98 +/- 1.24 findings in the negative aortogram group and 3.00 +/- 0.71 findings in the positive aortogram group) (P less than 0.001). All patients with aortic rupture had at least two major positive findings on admitting chest radiographs. Admission chest x-ray evidence of at least one major abnormality is a safe method of screening blunt chest trauma patients for thoracic aortography.

Adult

Current concepts of left ventricular pseudoaneurysm: pathophysiology, therapy, and diagnostic imaging methods.

Left ventricular pseudoaneurysm represents a cardiac rupture which is temporarily confined by pericardium and is amenable to curative surgical treatment. The case described illustrates several atypical features of its presentation and diagnosis, highlighting the importance of maintaining a sufficient clinical index of suspicion for this relatively uncommon, but potentially lethal entity. The use of various diagnostic imaging methods is described, including the first description of magnetic resonance imaging of ventricular pseudoaneurysm. The prospect of medical therapies directed toward the prevention of cardiac rupture, and thus pseudoaneurysm, is discussed in the context of its pathophysiology which involves alterations in the cardiac fibroskeletal support.

Aged

Imaging the diaphragm and its disorders.

Although a radiologic evaluation of the diaphragm is important in many clinical situations, visualization of the diaphragm is difficult because of its thinness, its domed contour, and its contiguity with abdominal soft tissues. Each clinical situation involving the diaphragm presents its own imaging difficulties, and each radiographic technique has advantages and disadvantages. No one modality is best for all situations. Often, several imaging modalities must be used to resolve the clinical question. The particular difficulties in diaphragmatic imaging are (1) distinguishing eventration from paralysis or hernia, (2) distinguishing lipoma from herniated omental fat, and (3) distinguishing unilateral paralysis from weakness and bilateral paralysis from respiratory fatigue. By selecting and applying the appropriate radiographic techniques, the radiologist can serve an essential role in assessing the disorders of the diaphragm.

Diagnostic Imaging

T1N0M0 lung cancer: evaluation with CT.

Although computed tomography (CT) is widely used in the evaluation of lung cancer, its use in the evaluation of clinical stage T1N0M0 lung cancer remains controversial. To evaluate the utility of CT, the authors studied 35 patients with clinical stage T1N0M0 lung cancer who underwent CT. Thoracotomy, mediastinoscopy, or fine-needle aspiration biopsy were performed in 26 of the patients. Metastases were proved in six of these patients, with CT demonstrating adenopathy in four of the six and a contralateral mass in one. Chest wall invasion was not demonstrated with CT in one patient. The overall prevalence of metastatic lesions in this group of 26 patients was 23.1%, with 15.4% of the 26 having unresectable lesions. CT demonstrated all metastatic lesions that precluded curative surgery. The results suggest that CT is clinically useful in the evaluation of clinical stage T1N0M0 lung cancer.

Adrenal Gland Neoplasms

Transthoracic aspiration needle biopsy: value in the diagnosis of pulmonary infections.

We reviewed 441 transthoracic needle aspiration biopsies to evaluate the use of the procedure in the diagnosis of pulmonary infections. Sixty-seven (15%) of the biopsies were performed because pulmonary infection was suspected. In these 67 cases, a specific diagnosis was made in 45 (67%). In 46 cases in which infection was ultimately found to be present, aspiration biopsy identified the organism in 35 (76%). Overall, clinically useful information was obtained in 54 (81%) of the 67 biopsies performed for pulmonary infection. In 369 biopsies performed for suspected malignant neoplasm, pulmonary infection was diagnosed in 13. The only significant complication was pneumothorax, which occurred in 18% of the biopsies. Chest tube placement was required in 5% of the biopsies. We conclude that transthoracic aspiration needle biopsy is of value in the diagnosis of suspected pulmonary infections.

Adult

Anatomic changes in the pelvis after uncomplicated vaginal delivery: a CT study on 14 women.

We analyzed CT scans of the pelvis made within 24 hr of an uncomplicated term vaginal delivery in 14 women to document the anatomic changes that occur in the immediate postpartum period. Scans were interpreted by three radiologists, and the results were compared with those from pelvic CT scans made from normal, age-matched, nonpregnant women. In addition to soft-tissue windows, bone windows also were obtained to assess the pubic symphysis and sacroiliac joints in both the postpartum women and the control subjects. The mean uterine length, transverse width, and anteroposterior diameter in the postpartum women (14 +/- 1.4, 12 +/- 1.5, and 9 +/- 1.6 cm, respectively) were significantly larger than in the nonpregnant women (7 +/- 1.4, 5 +/- 0.8, and 4 +/- 0.9 cm) (p less than .0001). CT scans showed intrauterine blood in nine of the postpartum women (64%), and three (21%) had intrauterine gas. There was widening of the sacroiliac joint in one (7%) of the postpartum women compared with none of the control subjects. Widening of the pubic symphysis was present in six (42%) of the postpartum women and in none of the control subjects. Six (42%) of the postpartum women had gas in the sacroiliac joints, 33% of which occurred bilaterally; gas in the pubic symphysis was seen in four (28%) of the postpartum scans. In one patient, an asymptomatic muscle hematoma was discovered. We conclude that normal changes in the pelvis after uncomplicated term vaginal delivery include enlargement of the uterus, intrauterine blood, widening of the symphysis and sacroiliac joints, and gas in the sacroiliac joints.

Adult

Treatment of pneumothoraces utilizing small caliber chest tubes.

Pneumothorax is a common problem in both hospitalized and emergency room patients. Eight-four pneumothoraces in 79 patients were treated using a No. 9 French catheter. In 76 cases, the catheter was attached to a flutter valve, and in eight cases, suction was applied. The No. 9 French catheter provided definitive treatment in 73 (87 percent) of the pneumothoraces. Causes of catheter failure included kinking, malposition, inadvertent removal by patient, occlusion of the tube or valve by pleural fluid, and large air leak. No complication attributable to tube placement occurred. When the flutter valve was employed, the patient was able to ambulate allowing for potential outpatient therapy. The tube was found to be easy to use, safe, and efficacious in the treatment of pneumothoraces.

Female

Subepithelial pyeloureteric lesions in patients with nephrostomy tubes.

Mural filling defects were identified in the renal pelves or ureters in five patients with nephrostomy tubes. In two patients, infection was documented. In the remaining patients, the urine was sterile. While typical ureteritis cystica associated with infection may be seen in patients with nephrostomy tubes, in some patients, other mechanisms are responsible for this appearance.

Adult