الفهرس 
Segmental and bronchial anatomy of lungsOnly 14 pages are availabe for public view
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Abstract
PE is a common and potentially fatal disorder for which treatment is effective and improves the chance of survival. PE is the third most common acute cardiovascular disease, after myocardial infarction and stroke, and it leads to thousands of deaths each year because it often goes undetected. However, the accurate diagnosis of acute pulmonary embolism can be difficult because of unreliable clinical and laboratory findings.
MDCT pulmonary angiography and venography for suspected venous thrombo-embolism are safe, readily available, and increasingly being used. Recent advances in technology allow faster scanning, thinner images, and more reproducible interpretations.
The most important advantage of CT over other imaging modalities is that both mediastinal and parenchymal structures are evaluated, and thrombus is directly visualized. Studies have shown that up to two thirds of patients with an initial suspicion of PE receive another diagnosis, some with potentially life-threatening diseases, such as aortic dissection, pneumonia, lung cancer, and pneumothorax. Most of these diagnoses are amenable to CT visualization, so that in many cases a specific etiology for the patients’ symptoms and important additional diagnoses can be established.
Use of high resolution multi-detector-CT protocols was shown to improve visualization of pulmonary arteries and the detection of small subsegmental emboli and such small peripheral clots that might have gone unnoticed in the past are now frequently detected, often in patients with minor symptoms.
Also recent advances in MSCTas Perfusion Weighted Color Maps and PaddleWheel Reformatted Images show that the non stopping advances in MSCT explains why MSCT pulmonary angiography is becoming the study of choice in diagnosis of PE.
Dual-energy CT pulmonary angiography does not expose patients to any significant additional radiation exposure over that of standard CT pulmonary angiography.
Dual-energy CT pulmonary angiography offers a functional aspect to CT pulmonary angiography and may improve its sensitivity for detecting sub-segmental emboli, the technique is yet to be validated in large-scale trials, but early studies suggest it is an accurate means of detecting perfusion defects secondary to acute PE.