Multislice CT imaging of pulmonary embolism

In recent years CT has been established as the method of choice for the dia gnosis of central pulmonary embolism (PE) to the level of the segmental art eries. The key advantage of CT over competing modalities is the reliable de tection of relevant alternative or additional disease causing the patient's symptoms. Although the clinical relevance of isolated peripheral emboli re mains unclear, the alleged poor sensitivity of CT for the detection of such small clots has to date prevented the acceptance of CT as the gold standar d for diagnosing PE. With the advent of multislice CT we can now cover the entire chest of a patient with 1-mm slices within one breath-hold. In compa rison with thicker sections., the detection rate of subsegmental emboli can be significantly increased with 1-mm slices. In addition. the interobserve r correlation which can be achieved with 1-mm sections by far exceeds the r eproducibility of competing modalities. Meanwhile use of multislice CT for a combined diagnosis of PE and deep venous thrombosis with the same modalit y appears to be clinically accepted. In the vast majority of patients who r eceive a combined thoracic and venous multislice CT examination the scan ei ther confirms the suspected diagnosis or reveals relevant alternative or ad ditional disease. The therapeutic regimen is usually chosen based on the fu nctional effect of embolic vascular occlusion. With the advent of fast CT s canning techniques, also functional parameters of lung perfusion can be non -invasively assessed by CT imaging. These advantages let multislice CT appe ar as an attractive modality for a non-invasive, fast, accurate, and compre hensive diagnosis of PE, its causes, effects, and differential diagnoses.