Pulmonary embolism (PE) is a serious and sometimes life-threatening condition that refers to a blood clot that occludes the arteries of the lung. Despite all improvements over the past decades,... Show morePulmonary embolism (PE) is a serious and sometimes life-threatening condition that refers to a blood clot that occludes the arteries of the lung. Despite all improvements over the past decades, diagnosing PE is still a difficult process due to the non-specific symptoms, which can frequently overlap with symptoms of other cardiopulmonary diseases. Currently recommended diagnostic strategies for suspected acute PE consist of standardized assessment of the clinical pre-test probability (CPTP) using validated clinical decision rules (CDRs) and D-dimer testing. PE is considered safely ruled out in patients with a non-high CPTP and a normal D-dimer test. Imaging tests as computed tomography pulmonary angiography (CTPA) are required in the case of a high CPTP and/or abnormal D-dimer test to confirm the diagnosis. The first part of this thesis describes the challenges of diagnosing PE in general and in specific clinically relevant patient subgroups. Moreover, this part evaluates the diagnostic performance of non-invasive diagnostic strategies for suspected PE in specific relevant patient subgroups. The second part of this thesis focuses on venous thrombotic complications in hospitalized patients with COVID-19. Show less
Venous thromboembolism (VTE) encompasses pulmonary embolism (PE) and deep vein thrombosis (DVT). DVT most commonly occurs in the deep veins of the lower extremity but can also occur in the veins of... Show moreVenous thromboembolism (VTE) encompasses pulmonary embolism (PE) and deep vein thrombosis (DVT). DVT most commonly occurs in the deep veins of the lower extremity but can also occur in the veins of upper extremity, abdomen and cerebrum. As symptoms of VTE are nonspecific, the diagnosis of VTE is based on diagnostic tests, including clinical decision rules (CDR), D-dimer tests and imaging. Although the diagnostic management of VTE has greatly advanced in recent years with the introduction of novel CDRs and high-sensitive D-dimer tests, the diagnosis may still be challenging in certain settings. The latter is mainly caused by the indirect way of thrombus visualisation by current imaging tests, such as by showing incompressibility with compression ultrasonography (CUS) or a filling defect on contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI).This thesis focuses on challenging settings for diagnosing VTE, including suspected recurrent ipsilateral DVT, upper extremity DVT, cerebral vein thrombosis and portal vein thrombosis. We studied a novel imaging technique called Magnetic Resonance Non-Contrast Thrombus Imaging (MR-NCTI) and its application in these different VTE settings. Show less