A chronic subdural hematoma (CSDH) is an intracranial bleeding between the outer two meninges of the brain due to rupture of cerebral veins or an inflammatory response in the subdural space.... Show moreA chronic subdural hematoma (CSDH) is an intracranial bleeding between the outer two meninges of the brain due to rupture of cerebral veins or an inflammatory response in the subdural space. Elderly patients using anti-thrombotic therapy are at higher risk for hematoma development. A rise in CSDH incidence is expected because of the aging population and increase in anti-thrombotic therapy use due to cardiovascular disease. To date, no treatment guideline exists regarding optimal CSDH treatment. Surgery with subdural drainage is the mainstay treatment. However, due to relevant surgical complications, a recurrence risk up to 30% and increased mortality in this vulnerable patient population, corticosteroid therapy is being administered as an alternative or adjuvant treatment modality.In this thesis we have shown that surgical treatment results in significantly better treatment outcome than medicinal approach by the corticosteroid dexamethasone in a retrospective study (chapter 2) as well as in a randomized controlled trial (chapter 3 and 4). Furthermore, we revealed radiological markers that are of prognostic value to predict treatment outcome after surgery (chapter 5) and dexamethasone therapy (chapter 6) in symptomatic CSDH patients. Show less
With the rising global health burden of aortic valve diseas and growing awareness of the consequences of severe AS, more patients are expected to be referred for aortic valve replacement.... Show moreWith the rising global health burden of aortic valve diseas and growing awareness of the consequences of severe AS, more patients are expected to be referred for aortic valve replacement. Multimodality imaging remains of paramount importance for proper patient selection, determining optimal timing of intervention and in the evaluation of therapy. For risk stratification and defining optimal timing of intervention, conventional and advanced echocardiography and computed tomography are crucial. Conventional echocardiography can be used to assess extra-aortic valvular cardiac damage in patients with severe AS. On top of conventional echocardiography, advanced echocardiography can provide additional insights. Left ventricular GLS by speckle tracking echocardiography has been suggested as a more sensitive marker of LV systolic dysfunction. LV GLS may be of help to define more optimal timing of intervention in asymptomatic patients with severe AS. Also, LV GLS may be of incremental value on top of conventional echocardiographic parameters for the assessment of cardiac injury. For the evaluation of prothesis function and durability after aortic valve implantation and detection of possible (late) complications, echocardiography is the mainstay imaging modality. Also, both conventional and advanced echocardiography can provide additional information on the effects of therapy on LV function and remodelling. Show less
The aim of this thesis is to determine diagnostic performance of machine learning in differentiating between atypical cartilaginous tumor (ACT) and high-grade chondrosarcoma (CS) based on radiomic... Show moreThe aim of this thesis is to determine diagnostic performance of machine learning in differentiating between atypical cartilaginous tumor (ACT) and high-grade chondrosarcoma (CS) based on radiomic features derived from magnetic resonance imaging (MRI) and computed tomography (CT). In chapter 2, the concept of radiomics of musculoskeletal sarcomas is introduced and a systematic review on radiomic feature reproducibility and validation strategies is conducted. In chapter 3, a preliminary study is performed to investigate the performance of MRI radiomics-based machine learning in discriminating ACT from high-grade CS, using a single-center cohort, in comparison with an expert radiologist. In chapter 4, the influence of interobserver segmentation variability on the reproducibility of CT and MRI radiomic features of cartilaginous bone tumors is assessed. In chapter 5, the performance of CT radiomics-based machine learning in discriminating ACT from high-grade CS of long bones is determined and validated using independent data from a multicenter cohort, compared to an expert radiologist. In chapter 6, the performance of MRI radiomics-based machine learning in differentiating between ACT and grade II CS of long bones is determined and validated using independent data from a multicenter cohort, in comparison with an expert radiologist. Finally, in chapter 7, the main results and implications of this thesis are summarized and discussed. 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
The objectives of this thesis were to elucidate the pathogenesis of metabolic heart disease, evaluate the associated changes in myocardial structure and contractile function, and determine the long... Show moreThe objectives of this thesis were to elucidate the pathogenesis of metabolic heart disease, evaluate the associated changes in myocardial structure and contractile function, and determine the long-term prognostic implications of subclinical myocardial dysfunction on all-cause mortality. Show less
This thesis showed that cardiac computed tomography may provide additional geometrical insights in valvular heart disease and cardiac remodeling. Further, computed tomography provides accurate... Show moreThis thesis showed that cardiac computed tomography may provide additional geometrical insights in valvular heart disease and cardiac remodeling. Further, computed tomography provides accurate anatomical images of the heart that may assist the planning of minimal invasive transcatheter cardiac procedures. Show less
