Acute pulmonary embolism (PE) is a frequent and potentially fatal condition with substantial morbidity and mortality ( ). Clinical symptoms and signs in acute PE may be nonspecific or similar to those of other conditions. It often goes undetected with its intricacy in diagnosis, which leads to thousands of deaths each year ( ). Multiple factors influence the selection of diagnostic tests. Clinical judgment is influenced by condition of the patient, clinical likelihood of PE, accessibility of diagnostic modalities, risks associated with use of iodinated contrast material, radiation exposure, and pregnancy ( ). Early diagnosis and proper therapy are imperative ( ).
The recent PIOPED II study concluded that clinical circumstances outline the sequence for diagnostic tests in patients with suspected acute PE ( ). However, symptoms of PE may be vague or nonspecific and often resemble symptoms associated with other diseases. In the setting of the acute PE, symptoms may be mild, and Stein et al. ( ) concluded that commonly anticipated symptoms may be absent, even in patients with severe PE. Investigators in the PIOPED II study suggested that objective pretest assessment of high or intermediate probability endorsed the use for diagnostic studies, but it is important to keep in mind that a low-probability objective clinical assessment does not exclude the diagnosis. PIOPED II investigators concluded that “maintenance of a high level of suspicion is critical” ( ).
In this issue of Academic Radiology , Weiss et al. ( ) report the results on pretest risk assessment in suspected acute PE among U.S. clinicians. This article is the third and final article published in Academic Radiology on results from the same survey ( ). Between September 2004 and February 2005, investigators ( ) conducted a mail survey of 855 physicians selected at random from three professional organizations (emergency medicine specialists, pulmonologists, and general internists). Authors received completed surveys from 240 (29.8%) physicians practicing in 44 states nationwide. The investigators raise significant questions and give important insights on the process of patient approach in suspected acute PE ( ).
In patients with suspected acute PE, it is imperative that objective risk assessment based on clinical criteria be made before imaging, as was recommended by PIOPED II investigators ( ). Weiss et al. ( ) investigate the pretest risk evaluation in patients with suspected acute PE throughout the country. In the published literature, three models for clinical pretest risk assessment have been proposed ( ) for precise and cost-effective evaluation of suspected acute PE. In clinical practice once the PE risk is defined, published practice guidelines can be applied ( ). Interestingly, Weiss et al. ( ) report that the majority of clinicians surveyed (72.5%) use an unstructured approach when estimating the pretest probability of acute PE, even though they are aware of published guidelines. However, it is reassuring that with the exception of the low-probability scenario, clinicians in the United States agreed on testing choices in suspected acute PE, regardless of the method or frequency of estimating pretest probability.
In the first paper ( ) of the set, authors asked how much clinical colleagues know about the equipment used in diagnosis of acute PE. Survey participants were asked how significant the accessibility of modern equipment was in their imaging decisions ( ). Authors concluded that although state-of-the-art equipment is important to clinicians practicing in the United States, they have limited knowledge of the equipment being used during computed tomographic pulmonary angiography (CTPA) and ventilation-perfusion (V/Q) scintigraphy scanning in their communities. Authors concluded that “radiologists should intensify efforts to familiarize their clinical colleagues with the equipment they use” ( ).
In the second paper ( ), the goal was to document existing imaging practices for diagnosing acute PE among physicians practicing in the United States. This investigation explored aspects related with these practices based on results of the survey ( ). Authors concluded that U.S. clinicians clearly favor CTPA in patients with suspected acute PE. Hospitals in the United States typically staff their CT scanning facilities 24 hours a day, providing extensive ease of use and timely reporting ( ). Low rate of inconclusive results and additional diagnostic capabilities are reasons for extensive acceptance of CTPA as diagnostic imaging in patients with acute PE.
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