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D F Worsley

Publications and source records attributed to D F Worsley.

25 records · Page 2Linked to original sources
PubMed1993

Ascending aortic dissection causing unilateral absence of perfusion on lung scanning.

A case of an ascending aortic dissection occurring in a patient 8 years after an aortic valve replacement is presented. The patient's initial clinical presentation was thought to be due to pulmonary embolism, and a ventilation-perfusion lung scan demonstrated mismatched absence of perfusion to the entire right lung. Aortography and findings at surgery demonstrated a type A dissection of the ascending aorta. The anatomic relationship of the aorta and pulmonary artery and their common tunica adventitia make the right pulmonary artery susceptible to extrinsic compression after aortic dissection. Although uncommon, dissection of the ascending aorta needs to be considered in patients who have undergone previous aortic valve surgery and demonstrate mismatched unilateral absence of perfusion to the right lung. Because anticoagulation is contraindicated in patients with acute aortic dissection, confirmation of the diagnosis with angiography usually is required.

Aged↗
PubMed1993

Chest radiographic findings in patients with acute pulmonary embolism: observations from the PIOPED Study.

PURPOSE: To determine the sensitivity, specificity, and positive and negative predictive values of chest radiographic findings in patients suspected of having acute pulmonary embolism (PE). MATERIALS AND METHODS: Chest radiographs of 1,063 patients with suspected PE were reviewed. PE was confirmed angiographically in 383 patients and excluded in 680 patients. RESULTS: The chest radiograph was interpreted as normal in only 12% of patients with PE. The most common chest radiographic finding in patients with PE was atelectasis and/or parenchymal areas of increased opacity; however, the prevalence was not significantly different from that in patients without PE. Oligemia (the Westermark sign), prominent central pulmonary artery (the Fleischner sign), pleural-based area of increased opacity (the Hampton hump), vascular redistribution, pleural effusion, elevated diaphragm, and enlarged hilum were also poor predictors of PE. CONCLUSION: Although chest radiographs are essential in the investigation of suspected PE, their main value is to exclude diagnoses that clinically mimic PE and to aid in the interpretation of the ventilation-perfusion scan.

Acute Disease↗
PubMed1993

Detailed analysis of patients with matched ventilation-perfusion defects and chest radiographic opacities.

We performed a retrospective evaluation of the data obtained from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study to determine the prevalence and distribution of pulmonary embolism (PE) in patients with matching ventilation-perfusion (V/Q) defects and chest radiographic opacities (triple matches). From the 1,487 patients in whom diagnostic V/Q scans were obtained, 247 (17%) patients were recorded as having matching V/Q defects and chest radiograph opacities in at least one lung zone. Diagnostic angiograms were available for 275 lung zones (233 patients) which demonstrated matching V/Q defects and chest radiograph opacities. The overall prevalence of PE in all lung zones with triple matches was 26%. The prevalences of PE in the upper, middle and lower lung zones were 11%, 12% and 33%, respectively. Pulmonary embolism was significantly more common in lower lung zone triple matches compared with the upper and middle lung zone triple matches (p < 0.005). There was no correlation between the size of the V/Q and chest radiographic abnormalities and the prevalence of PE. We conclude that in patients with matching V/Q defects and chest radiographic opacities isolated to the upper and middle zones the V/Q scan can be interpreted as representing a low probability of PE. Similar findings in the lower lung zones represent an intermediate probability of PE. The application of this modification to V/Q scan interpretation criteria will aid in reducing the number of intermediate V/Q lung scan interpretations.

Humans↗
PubMed1993

Role of radionuclide imaging in patients with suspected pulmonary embolism.

The accurate diagnosis of acute pulmonary embolism often represents a challenge to clinicians. The ventilation/perfusion (V/Q) lung scan provides a safe, noninvasive technique, which has been widely used in the diagnosis of pulmonary embolism. Although some controversy still exists in the management of patients with suspected pulmonary embolism, diagnostic strategies for investigating patients have incorporated V/Q scanning, noninvasive venous studies of the lower extremities and clinical assessment of the likelihood of pulmonary embolism. The combination of these strategies will provide acceptable diagnostic accuracy for evaluating patients with suspected pulmonary embolism in the majority of cases.

Humans↗
PubMed1992

Comparison of stress-only vs. stress/rest with technetium-99m methoxyisobutylisonitrile myocardial perfusion imaging.

Unlike conventional thallium-201 myocardial imaging, technetium-99m methoxyisobutylisonitrile (MIBI) requires separate stress and rest injections. We prospectively studied 148 consecutive patients referred for myocardial perfusion studies to determine the diagnostic value of rest images once normal exercise or dipyridamole tomographic images had been obtained. In patients referred with no history of previous myocardial infarction in whom the diagnosis of coronary artery disease was suspected, 45 of 109 (41%) patients had normal stress tomographic images. Obtaining rest images did not alter the final interpretation in any of these cases. From this we infer that in patients with normal images after exercise or dipyridamole administration and no past history of myocardial infarction, 99mTc-MIBI rest images are not required. This provides several advantages including increased speed of diagnosis, decreased patient radiation exposure, improved cost efficiency and decreased demand on tomographic camera time.

Contrast Media↗
PubMedDate not supplied

A detailed evaluation of patients with acute pulmonary embolism and low- or very-low-probability lung scan interpretations.

BACKGROUND: To determine the clinical characteristics of patients with pulmonary embolism (PE) and low- or very-low-probability ventilation-perfusion lung scan interpretations. METHODS: A retrospective analysis of the data obtained during the Prospective Investigation of Pulmonary Embolism Diagnosis study was performed. The clinical characteristics of patients with acute PE and low- or very-low-probability lung scan interpretation (false-negative interpretations) were compared with patients who had low- or very-low-probability lung scan interpretations and no evidence of acute PE (true-negative interpretations). RESULTS: Of the 1493 patients who gave consent to participate in the Prospective Investigation of Pulmonary Embolism Diagnosis study, 399 patients had angiographic or autopsy evidence of acute PE. Pulmonary embolism was excluded in 960 patients. Patients with false-negative lung scan interpretations more commonly had a history of immobilization (P < .0001), trauma to the lower extremities (P < .003), recent surgery (P < .002), or central venous instrumentation (P < .04) compared with patients with true-negative lung scan interpretations. In patients with low- or very-low-probability lung scan interpretations and none of the above-mentioned risk factors, the prevalence of PE was only 4.5%. In contrast, for patients with low- or very-low-probability lung scan interpretations and two or more of the above-mentioned risk factors, the prevalence of PE was 21%. CONCLUSIONS: Patients with a history of immobilization, trauma to the lower extremities, recent surgery, or central venous instrumentation were more likely to have false-negative lung scan interpretations. Therefore, this population warrants special attention when deciding on the need for peripheral venous studies or angiography in patients with low- or very-low-probability lung scan interpretation.

Acute Disease↗