Diagnosis of pulmonary embolism with multislice spiral CT

In recent years CT has been established as the method of choice for the dia gnosis of central pulmonary embolism to the level of the segmental arteries . The key advantage of CT over competing modalities is the reliable detecti on of relevant alternative or additional disease causing the patient's symp toms. Although the clinical relevance of isolated peripheral emboli remains 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 standard for diagnosing pulmonary embolism. 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 comparison with thicker sections the detection rate of subsegmental em boli can be significantly increased with 1-mm sections. In addition the int erobserver correlation which can be achieved with 1-mm sections by far exce eds the reproducibility of competing modalities. Meanwhile use of multislic e CT for a combined diagnosis of pulmonary embolism and deep venous thrombo sis with the same modality appears to be clinically accepted. In the vast m ajority of patients who receive a combined thoracic and venous multislice C T examination the scan either confirms the suspected diagnosis or reveals r elevant alternative or additional disease. The therapeutic regimen is usual ly chosen based on the functional effect of embolic vascular occlusion. Wit h the advent of fast CT scanning techniques, also functional parameters of lung perfusion can be non-invasively assessed by CT imaging. These advantag es let multislice CT appear as an attractive modality for a non-invasive, f ast, accurate and comprehensive diagnosis of pulmonary embolism, its causes , effects and differential diagnoses.