This thesis aims to assess the differences and similarities between autoantibody-positive and autoantibody-negative RA from the start of complaints to the end of the disease. The described research... Show moreThis thesis aims to assess the differences and similarities between autoantibody-positive and autoantibody-negative RA from the start of complaints to the end of the disease. The described research was performed with the ultimate goal to clarify whether autoantibody-negative and autoantibody-positive RA are distinct diseases that require different diagnoses and treatment. 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
Studies in this thesis focused on the use of MRI in patients with early inflammatory arthritis. Studies were focused on: the diagnostic value of MRI, predictive value of MRI findings for the... Show moreStudies in this thesis focused on the use of MRI in patients with early inflammatory arthritis. Studies were focused on: the diagnostic value of MRI, predictive value of MRI findings for the development of erosions, associations between age and MRI findings, the use of MRI for the development of new disease activity scores and patient reported outcomes in patients with rheumatoid arthritis. Show less
Early identification of patients with subclinical cardiovascular or cerebrovascular disease manifestation is highly relevant as organ damage might still be reversible. Imaging can be used for... Show moreEarly identification of patients with subclinical cardiovascular or cerebrovascular disease manifestation is highly relevant as organ damage might still be reversible. Imaging can be used for risk stratification and optimizing individual prevention and treatment strategies in patients with metabolic syndrome. This thesis evaluates MR and CT imaging techniques for identifying risk factors and subclinical disease in metabolic syndrome. Show less
De belangrijkste resultaten van dit proefschrift: de ASAS classificatie criteria voor axSpA blijken robuust en zijn goed toepasbaar in een setting waarbij de waarschijnlijkheid op axSpA lager is... Show moreDe belangrijkste resultaten van dit proefschrift: de ASAS classificatie criteria voor axSpA blijken robuust en zijn goed toepasbaar in een setting waarbij de waarschijnlijkheid op axSpA lager is dan waarin de criteria ontwikkeld zijn. Daarnaast is er op basis van bevindingen in dit proefschrift een belangrijke aanpassing doorgevoerd in een hulpmiddel dat reumatologen begeleidt in het diagnostische proces van (vroege) axSpA. Tevens is het MRI protocol van het SPACE cohort aangepast nadat de toegevoegde waarde van het toedienen van een contrastvloeistof bij het maken van MRI’s nihil bleek te zijn, met als resultaat dat er sinds april 2012 geen MRI’s meer worden gemaakt met de toediening van gadolinium. Dit proefschrift biedt ook adequate handvatten voor verder onderzoek naar de optimale definitie van een positieve MRI. Bovendien worden discrepanties aangaande de beoordeling door verschillende soorten lezers van afwijkingen in de rug (op röntgenfoto’s en MRI’s) aan het licht gebracht waardoor de vraag naar voren komt of training in het onderscheiden van axSpA afwijkingen en afwijkingen die niet gerelateerd zijn aan axSpA van potentiële belang is op de betrouwbaarheid van het beoordelen van afwijkingen in de rug. De onderzoeken in dit proefschrift leveren een bijdrage aan betere herkenning en behandeling van axSpA. Show less
The main objective of this thesis is to compare bony decompression with implantation of interspinous process devices (IPDs) in patients with intermittent neurogenic claudication (INC) caused by... Show moreThe main objective of this thesis is to compare bony decompression with implantation of interspinous process devices (IPDs) in patients with intermittent neurogenic claudication (INC) caused by lumbar spinal stenosis (LSS). A national survey among Dutch spine surgeons is presented about the usual care of patients with intermittent neurogenic claudication caused by lumbar spinal stenosis. Surgeons' expectations of different treatment options are presented. The existing evidence on interspinous implant surgery will be systematically reviewed. Results of treatment with IPDs are compared with other (conservative) treatment options. The Foraminal Enlargement Lumbar Interspinosus distraXion (FELIX) trial is described. This double-blind, multicenter, randomized (cost)effectiveness study was designed to answer the question whether treatment with IPDs would be more (cost) effective compared with conventional bony decompression. Short-term results (eight weeks), long-term results (one and two year) and results in different subgroups are described in this thesis. The analysis based on total direct and indirect costs of both procedures (treatment with IPD and bony decompression) are also presented. INC suitable for surgical treatment. The compression on MR images was evaluated and correlated with baseline complaints and long-term clinical outcome. Show less
The general objective of this thesis was to investigate new (quantitative) MR techniques and MR markers in the light of both AD and cerebral aging. The quantitative MR techniques that we used were... Show moreThe general objective of this thesis was to investigate new (quantitative) MR techniques and MR markers in the light of both AD and cerebral aging. The quantitative MR techniques that we used were MTI, tCBF and WSS measurements. The new markers we studied were cerebral microbleeds and iron accumulation in the basal ganglia. In chapter 2 we investigated whether MTI changes could be detected in the GM, WM or both in patients suffering from MCI or AD. Using MTI we found evidence for structural brain changes in both GM and WM of patients with MCI and AD. Furthermore, these MTI changes were related to cognitive impairment as expressed by the mini mental state examination (MMSE) score. These findings imply that cerebral changes can be detected in both GM and WM even before patients are clinically demented. The finding of MTI changes in the GM might relate to classical AD type pathology, whereas WM MTI changes could indicate concomitant vascular pathology. The findings in chapter 2 raised the question of how the MTI changes found in this study are distributed over the GM and WM. This was investigated in chapter 3. In this study we showed that brain damage, as detected by MTI, is widespread over the lobes in both AD and MCI patients whereas GM damage is more focally present in the temporal and frontal lobe of MCI patients. These findings are compatible with the knowledge that GM damage originates from the temporal lobe in AD. This interpretation is further supported by the observed independent association between temporal GM peak height and cognitive decline. MTI changes were found in all four lobes of the MCI patients investigated in this study and show the involvement of a diffuse process affecting the WM even before patients are clinically demented, a finding potentially explained by the presence of diffuse vascular pathology. Chapter 4 shows that the tCBF is strongly associated with parenchymal volume rather than age and, although much weaker, with the severity of WMHs. Although the association between tCBF and parenchyma volume seems straightforward, this finding has important implications for future studies. Volume flow measurements should be corrected for parenchymal volume ratherthan age in all future studies in which flow measurements are being used as a diagnostic tool. In addition, studies including elderly patients or patients with a pathological increase of WMHs, such as diabetic type II subjects, should also correct their tCBF measurements for WMH volumes. Chapter 5 shows that hemodynamic conditions of the carotid and basilar arteries, as expressed in lower WSS parameters, are worse in both MCI and AD compared to controls. In addition, the WSS parameters were found to correlate strongly with cognition. Again, this study is additional evidence for an important role of vascular pathology in the development of AD. In chapter 6, we found a high prevalence of microbleeds in a population of patients suffering from vascular disease or at high risk of developing this condition. Age, hypertension and WMH were the most important risk factors for microbleeds, especially when located in the cortico-subcortical junction and basal ganglia. Regarding the associations between the presence and location of microbleeds on the one hand and parameters of cognitive functioning on the other, chapter 7 shows that microbleeds located infratentorially are associated with impaired cognitive functioning in the aging population with increased vascular risk factors. This suggests that in elderly individuals microbleeds in the posterior fossa should be considered a sign of small vessel disease with potential functional consequences. The semi-quantative scale for scoring basal ganglia hypo-intensity on T2*- weighted imaging presented in chapter 8 was associated with markers of neurodegeneration. This study showed that low signal intensity of the caudate nucleus T2*-weighted MR is a frequent finding which is associated with more cerebral atrophy, a higher load of WMH and a higher load of invisible changes in both cortical GM and NAWM non-demented elderly. Furthermore, hypo- intensity limited to the globus pallidus and putamen was not associated with any of these parameters of neurodegeneration. In chapter 9 we present a method for automated detection and classification of hypo-intense regions on T2-weighted MR images of the basal ganglia. In this chapter we not only show an association between basal ganglia hypo-intensity and cardiovascular risk factors but also with measures of cognitive functioning. From this we conclude that hypo-intensity of the basal ganglia on T2-weighted MR is not only a radiological finding accompanying cerebral aging but also an independent marker of neurodegeneration. Show less
Brain function has long been the realm of philosophy, psychology and psychiatry and since the mid 1800s, of histopathology. Through the advent of magnetic imaging in the end of the last century, an... Show moreBrain function has long been the realm of philosophy, psychology and psychiatry and since the mid 1800s, of histopathology. Through the advent of magnetic imaging in the end of the last century, an in vivo visualization of the human brain became available. This thesis describes the development of two unique techniques, imaging of diffusion of water protons and manganese enhanced imaging, that both allow for the depiction of white matter tracts. The reported studies show, that these techniques can be used for a three-dimensional depiction of fiber bundles and that quantitative measures reflecting fiber integrity and neuronal function can be extracted from such data. In clinical applications, the potential use of the developed methods is illustrated in human gliomas, as measure for fiber infiltration, and in spinal cord injury, to monitor potential neuroprotective and __regenerative medication. Show less
