Anders Eklund

Anders Eklund
Umeå University | UMU · Department of Radiation Sciences

PhD

About

174
Publications
20,548
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
4,028
Citations
Citations since 2017
56 Research Items
2396 Citations
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500

Publications

Publications (174)
Article
Background Maintaining cerebral perfusion pressure in the brain when a carotid artery is closed during vascular surgery is critical for avoiding intraoperative hypoperfusion and risk of ischemic stroke. Here we propose and evaluate a method based on computational fluid dynamics for predicting patient-specific cerebral perfusion pressures at carotid...
Article
Full-text available
Background The pressure difference between the eye and brain in upright postures may be affected by compartmentalization of the optic nerve subarachnoid space (ONSAS). Both pressure and deformation will depend on the microstructures of the ONSAS, and most likely also on ocular glymphatic clearance. Studying these factors could yield important knowl...
Article
Full-text available
Innovation has become increasingly important for most industries to cope with rapid technological changes as well as changing societal needs. Even though there are many sectors with specific needs when it comes to supporting innovation, the medical technology sector is facing several unique challenges that both increases the lead-time from idea to...
Article
Objective: High cerebral arterial pulsatility index (PI), white matter lesions (WMLs), enlarged perivascular spaces (PVSs), and lacunar infarcts are common findings in the elderly population, and considered indicators of small vessel disease (SVD). Here, we investigate the potential temporal ordering among these variables, with emphasis on determi...
Article
Full-text available
Visualizing medical images from patients as physical 3D models (phantom models) have many roles in the medical field, from education to preclinical preparation and clinical research. However, current phantom models are generally generic, expensive, and time-consuming to fabricate. Thus, there is a need for a cost- and time-efficient pipeline from m...
Preprint
Full-text available
Visualizing medical images from a patient as physical 3D-models (phantom models) has potential roles in the medical field, from education to preclinical preparation and clinical research. However, current phantom models are generally generic, expensive, and time-consuming to fabricate. Thus, there is a need for a cost-and time-efficient pipeline fr...
Article
Full-text available
Introduction The treatment of hydrocephalus has been a topic of intense research ever since the first clinically successful use of a valved cerebrospinal fluid shunt 72 years ago. While ample studies elucidating different phenomena impacting this treatment exist, there are still gaps to be filled. Specifically, how intracranial, intrathecal, arteri...
Article
Purpose Large trans-lamina cribrosa pressure differences (TLCPD) have been suggested to play a role in the development of normal-tension glaucoma. To avoid substantial increases in the TLCPD in upright postures, we hypothesize that a collapse of the optic nerve subarachnoid space (ONSAS) protects the eyes from large TLCPDs when we stand up, i.e., b...
Article
Full-text available
Alterations in cerebral blood flow are common in several neurological diseases among the elderly including stroke, cerebral small vessel disease, vascular dementia, and Alzheimer's disease. 4D flow magnetic resonance imaging (MRI) is a relatively new technique to investigate cerebrovascular disease, and makes it possible to obtain time-resolved blo...
Article
Background: To describe preliminary results of a multi-center, randomized, blinded, placebo-controlled, pilot trial of shunt surgery in idiopathic normal pressure hydrocephalus (iNPH). Methods: Five sites of the Adult Hydrocephalus Clinical Research Network (AHCRN) randomized 18 patients scheduled for ventriculoperitoneal shunting based on CSF-drai...
Article
Full-text available
Objective: A clinically feasible, non-invasive method to quantify blood flow, hemodynamics, and collateral flow in the vertebrobasilar arterial tree is missing. The objective of this study was to evaluate the feasibility of quantifying blood flow and blood flow patterns using 4D flow magnetic resonance imaging (MRI) in consecutive patients after an...
Article
Background and purpose: Systematic analysis of angulation-related variability of idiopathic normal pressure hydrocephalus imaging biomarkers has not been published yet. Our aim was to evaluate the variability of these radiologic biomarkers with respect to imaging plane angulation. Materials and methods: Eighty subjects (35 with clinically confir...
Article
Full-text available
Purpose: We hypothesize that a collapse of the optic nerve subarachnoid space (ONSAS) in the upright posture may protect the eyes from large translamina cribrosa pressure differences (TLCPD) believed to play a role in various optic nerve diseases (e.g., glaucoma). In this study, we combined magnetic resonance imaging (MRI) and mathematical modelin...
Article
Full-text available
Intracranial arterial stiffening is a potential early marker of emerging cerebrovascular dysfunction and could be mechanistically involved in disease processes detrimental to brain function via several pathways. A prominent consequence of arterial wall stiffening is the increased velocity at which the systolic pressure pulse wave propagates through...
Article
BACKGROUND Gait and balance impairment are typical symptoms of idiopathic normal pressure hydrocephalus (INPH), implicating that falls may afflict these patients. OBJECTIVE To investigate falls, related injuries, and associated psychological features, before and after shunt surgery for INPH and compared to the general population. METHODS The stud...
Article
Full-text available
Carotid near-occlusion is a frequently overlooked diagnosis when CTA examinations are assessed in routine practice. To evaluate the potential value of phase-contrast MR imaging in identifying near-occlusion, we examined 9 carotid near-occlusions and 20 cases of conventional ≥50% carotid stenosis (mean stenosis degree, 65%) with phase-contrast MR im...
Article
Full-text available
Background and purpose Carotid stenosis can profoundly impact cerebral hemodynamics that cannot simply be inferred from the degree of stenosis. We quantified and mapped the distribution of blood flow rate in cerebral arteries before and after carotid endarterectomy using four-dimensional phase-contrast magnetic resonance imaging (4D flow MRI). Met...
Article
Full-text available
Microvascular damage in the hippocampus is emerging as a central cause of cognitive decline and dementia in aging. This could be a consequence of age-related decreases in vascular elasticity, exposing hippocampal capillaries to excessive cardiac-related pulsatile flow that disrupts the blood-brain barrier and the neurovascular unit. Previous studie...
Article
Full-text available
An internal carotid artery (ICA) stenosis can potentially decrease the perfusion pressure to the brain. In this study, computational fluid dynamics (CFD) was used to study if there was a hemispheric pressure laterality between the contra- and ipsilateral middle cerebral artery (MCA) in patients with a symptomatic ICA stenosis. We further investigat...
Article
Full-text available
Purpose To examine feasibility of phase‐contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls. Methods Sixteen patients with treated NTG and 16 age‐ and sex‐matched healthy controls underwent PCMRI using a 3‐Tesla scanner...
Article
Full-text available
Purpose: To investigate if decrease of IOP affects the volumetric blood flow rate in the ophthalmic artery (OA) in patients with previously untreated ocular hypertension. Methods: Subjects with untreated ocular hypertension (n = 30; mean age 67 ± 8 years; 14 females) underwent ophthalmologic examination and a 3-Tesla magnetic resonance imaging i...
Article
Objective: Idiopathic normal pressure hydrocephalus (INPH) is a dementia treatable by insertion of a shunt that drains CSF. The cause of the disease is unknown, but a vascular pathway has been suggested. The INPH-CRasH (Comorbidities and Risk Factors Associated with Hydrocephalus) study was a modern epidemiological case-control study designed to p...
Article
Full-text available
Objective The spaceflight–associated neuro–ocular syndrome (SANS) affects astronauts on missions to the International Space Station (ISS). SANS has blurred vision and ocular changes as typical features. The objective of this study was to investigate if microgravity can create deformations or movements of the eye and/or optic nerve, and if such chan...
Article
Full-text available
Background: Infusion testing is a common procedure to determine whether shunting will be beneficial in patients with normal pressure hydrocephalus. The method has a well-developed theoretical foundation and corresponding mathematical models that describe the CSF circulation from the choroid plexus to the arachnoid granulations. Here, we investigat...
Article
Full-text available
Cerebral small vessel disease (SVD) is a major cause of stroke and cognitive impairment. However, the underlying mechanisms behind SVD are still poorly understood. High cerebral arterial pulsatility has been suggested as a possible cause of SVD. In population studies, arterial pulsatility has been linked to white matter hyperintensities (WMH), cere...
Article
Objective: Subdural hematomas and hygromas (SDHs) are common complications in idiopathic normal pressure hydrocephalus (iNPH) patients with shunts. In this registry-based study, patients with shunted iNPH were screened nationwide to identify perioperative variables that may increase the risk of SDH. Methods: The Swedish Hydrocephalus Quality Reg...
Article
Full-text available
Background: Communicating hydrocephalus is a disease where the cerebral ventricles are enlarged. It is characterized by the absence of detectable cerebrospinal fluid (CSF) outflow obstructions and often with increased CSF pulsatility measured in the cerebral aqueduct (CA). We hypothesize that the cardiac-related pulsatile flow over the CA, with fa...
Article
Recent reports have suggested that age-related arterial stiffening and excessive cerebral arterial pulsatility cause blood–brain barrier breakdown, brain atrophy and cognitive decline. This has spurred interest in developing non-invasive methods to measure pulsatility in distal vessels, closer to the cerebral microcirculation. Here, we report a met...
Article
Full-text available
Background: Four-dimensional flow magnetic resonance imaging (4D flow MRI) enables efficient investigation of cerebral blood flow pulsatility in the cerebral arteries. This is important for exploring hemodynamic mechanisms behind vascular diseases associated with arterial pulsations. Purpose: To investigate the feasibility of pulsatility assessm...
Article
Purpose: Numerous radiological measures have been proposed as imaging biomarkers of idiopathic normal pressure hydrocephalus (iNPH), however, the number of studies systematically comparing their diagnostic values remains limited. The study objective was to compare the diagnostic performance of fifteen cross-sectional imaging iNPH biomarkers. Mate...
Preprint
Full-text available
Background Infusion testing is a common procedure to determine whether shunting will be beneficial in patients with normal pressure hydrocephalus. The method has a well-developed theoretical foundation and corresponding mathematical models that describe the CSF circulation from the choroid plexus to the arachnoid granulations. Here, we investigate...
Article
Background: The short- and long-term impact of cerebrospinal fluid shunting on quality of life (QoL) in idiopathic normal pressure hydrocephalus (INPH) is poorly understood. Objective: To investigate QoL in shunted INPH patients compared to the population and to investigate which factors influence QoL in INPH. Methods: INPH patients consecutiv...
Article
Full-text available
Objective: The collapse of the internal jugular vein (IJV) regulates intracranial pressure (ICP) in upright body positions. The cross-section area (CSA) is therefore of interest when studying the effects of postural changes in various neurological diseases. We have developed a semi-automatic segmentation method, which tracks the CSA of the IJV in u...
Article
Full-text available
Background Cerebral injury may alter the autoregulation of cerebral blood flow. One index for describing cerebrovascular state is the pressure reactivity (PR). Little is known of whether PR is associated with measures of brain metabolism and indicators of ischemia and cell damage. The aim of this investigation was to explore whether increased inter...
Article
Full-text available
Background and Purpose— Four-dimensional phase-contrast magnetic resonance imaging enables quantification of blood flow rate (BFR; mL/min) in multiple cerebral arteries simultaneously, making it a promising technique for hemodynamic investigation in patients with stroke. The aim of this study was to quantify the hemodynamic disturbance and the comp...
Article
OBJECTIVE The Computerized General Neuropsychological INPH Test (CoGNIT) provides the clinician and the researcher with standardized and accessible cognitive assessments in patients with idiopathic normal pressure hydrocephalus (INPH). CoGNIT includes tests of memory, executive functions, attention, manual dexterity, and psychomotor speed. Investig...
Article
Full-text available
Background Accelerated 4D flow MRI allows for high‐resolution velocity measurements with whole‐brain coverage. Such scans are increasingly used to calculate flow rates of individual arteries in the vascular tree, but detailed information about the accuracy and precision in relation to different postprocessing options is lacking. Purpose To evaluat...
Article
OBJECTIVE Intracranial pressure (ICP), outflow resistance (Rout), and amplitude of cardiac-related ICP pulsations (AMPs) are established parameters to describe the CSF hydrodynamic system and are assumed, but not confirmed, to be disturbed in idiopathic normal pressure hydrocephalus (INPH). The aim of this study was to compare the CSF hydrodynamic...
Article
Full-text available
Objective: With a 10-minute 4D flow MRI scan, the distribution of blood flow to individual arteries throughout the brain can be analyzed. This technique has potential to become a biomarker for treatment decisions, and to predict prognosis after stroke. To efficiently analyze and model the large dataset in clinical practice, automatization is needed...
Article
Full-text available
Introduction Ventriculo‐peritoneal cerebrospinal fluid (CSF) shunt is the most common method of treating pediatric hydrocephalus. The Codman microadjustable valve (CMAV) is a CSF shunt constructed for children. The objective of the study was (a) to analyze complications after insertion of a CMAV shunt in hydrocephalic children, (b) to analyze compl...
Article
Objectives: A third of patients with stroke acquire spatial neglect associated with poor rehabilitation outcome. New effective rehabilitation interventions are needed. Scanning training combined with multisensory stimulation to enhance the rehabilitation effect is suggested. In accordance, we have designed a virtual reality-based scanning training...
Article
Full-text available
Purpose of review: A pressure difference between the intraocular and intracranial compartments at the site of the lamina cribrosa has been hypothesized to have a pathophysiological role in several optic nerve head diseases. This paper reviews the current literature on the translamina cribrosa pressure difference (TLCPD), the associated pressure gr...
Article
Recent interest in intracranial pressure (ICP) in the upright posture has revealed that the mechanisms regulating postural changes in ICP are not fully understood. We have suggested an explanatory model where the postural changes in ICP depend on well-established hydrostatic effects in the venous system and where these effects are interrupted by co...
Article
OBJECTIVE Subdural hematoma (SDH) is the most common serious adverse event in patients with shunts. Adjustable shunts are used with increasing frequency and make it possible to noninvasively treat postoperative SDH. The objective of this study was to describe the prevalence and treatment preferences of SDHs, based on fixed or adjustable shunt valve...
Article
Full-text available
Purpose: To test the hypothesis that normal-tension glaucoma (NTG) is caused by an increased pressure difference across the lamina cribrosa (LC) related to a low intracranial pressure (ICP). Design: Prospective case-control study. Participants: Thirteen NTG patients (9 women; median 71 [range: 56-83] years) were recruited for investigation wit...
Article
OBJECTIVE Adverse events related to shunt surgery are common and might have a negative effect on outcome in patients with idiopathic normal pressure hydrocephalus (INPH). The authors’ objectives were to establish the frequencies of epilepsy, headache, and abdominal pain and determine their impact on patient quality of life (QOL), in long-term follo...
Article
Full-text available
Background: Three different types of anti-siphon devices (ASDs) have been developed to counteract siphoning-induced overdrainage in upright posture. However, it is not known how the different ASDs affect CSF dynamics under the complex pressure environment seen in clinic due to postural changes. We investigated which ASDs can avoid overdrainage in...
Article
Full-text available
Background Intracranial pressure (ICP) is directly related to cranial dural venous pressure (Pdural). In the upright posture, Pdural is affected by the collapse of the internal jugular veins (IJVs) but this regulation of the venous pressure has not been fully understood. A potential biomechanical description of this regulation involves a transmissi...
Article
Background: Neuropathologically, Alzheimer's disease (AD) is characterized by accumulation of a 42 amino acid peptide called amyloid-β (Aβ42) in extracellular senile plaques together with intraneuronal inclusions of hyperphosphorylated tau protein in neurofibrillary tangles and neuronal degeneration. These changes are reflected in the cerebrospina...
Article
Full-text available
Measurement of intracranial pressure (ICP) is necessary in many neurological and neurosurgical diseases. To avoid lumbar puncture or intracranial ICP probes, non-invasive ICP techniques are becoming popular. A recently developed technology uses two-depth Doppler to compare arterial pulsations in the intra- and extra-cranial segments of the ophthalm...
Article
Objective: To assess the complete vascular risk factor (VRF) profile of idiopathic normal pressure hydrocephalus (INPH) using a large sample of representative patients with INPH and population-based controls to determine the extent to which vascular disease influences INPH pathophysiology. Methods: All patients with INPH who underwent shunting i...
Article
Full-text available
Improved whole brain angiographic and velocity-sensitive MRI is pushing the boundaries of noninvasively obtained cerebral vascular flow information. The complexity of the information contained in such datasets calls for automated algorithms and pipelines, thus reducing the need of manual analyses by trained radiologists. The objective of this work...
Article
Full-text available
Background: More than half of astronauts develop ophthalmic changes during long-duration spaceflight consistent with an abnormal intraocular and intracranial pressure (IOP, ICP) difference. The aim of our study was to assess IOP and ICP during head-down tilt (HDT) and the additive or attenuating effects of 1% CO2 and lower body negative pressure (...
Article
Background: A noninvasive method to monitor changes in intracranial pressure (ICP) is required for astronauts on long-duration spaceflight who are at risk of developing the Visual Impairment/Intracranial Pressure syndrome that has some, but not all of the features of idiopathic intracranial hypertension. We assessed the validity of distortion prod...
Article
Objectives: Increased aqueduct cerebrospinal fluid (CSF) flow pulsatility and, recently, a reversed CSF flow in the aqueduct have been suggested as hallmarks of idiopathic normal pressure hydrocephalus (INPH). However, these findings have not been adequately confirmed. Our objective was to investigate the flow of blood and CSF in INPH, as compared...
Article
Objective: The discovery of a posture-dependent effect on the difference between intraocular pressure (IOP) and intracranial pressure (ICP) at the level of lamina cribrosa could have important implications for understanding glaucoma and idiopathic intracranial hypertension and could help explain visual impairments in astronauts exposed to microgra...
Article
Alterations in cerebral hemodynamics in microgravity are hypothesized to occur during spaceflight and could be linked to the Visual Impairment and Intracranial Pressure syndrome. Head down tilt (HDT) is frequently used as a ground-based analog to simulate cephalad fluid shifts in microgravity, however its effects on cerebral hemodynamics have not b...
Article
Full-text available
Background: There is a lack of effective treatment for neglect. We have developed a new training method, RehAtt™. The objective of this study was to determine whether RehAtt™ improves spatial attention in chronic neglect after stroke. Methods: RehAtt™ consists of a computer with monitor, 3D glasses, and a force feedback interface (Robotic pen) g...
Article
Full-text available
Background A vascular disease could be involved in pathophysiology of normal pressure hydrocephalus (INPH). If so, there should be an association between INPH and cerebral microbleeds (CMB). This study aims to analyze if CMB are associated with INPH. Methods In this case-control study we included 14 patients with INPH (mean age 76 years, 60 % fema...
Article
Full-text available
Excessive pulsatile flow caused by aortic stiffness is thought to be a contributing factor for several cerebrovascular diseases. The main purpose of this study was to describe the dampening of the pulsatile flow from the proximal to the distal cerebral arteries, the effect of aging and sex, and its correlation to aortic stiffness. Forty-five health...
Article
Full-text available
Objectives: In order to introduce 4D flow magnetic resonance imaging (MRI) as a standard clinical instrument for studying the cerebrovascular system, new and faster postprocessing tools are necessary. The objective of this study was to construct and evaluate a method for automatic identification of individual cerebral arteries in a 4D flow MRI ang...
Article
Background: If patients with idiopathic normal pressure hydrocephalus (INPH) also have depression, this could have important clinical ramifications in assessment and management of their cognitive function and response to shunting. In many dementias, depression is overrepresented, but the prevalence of depression in shunted patients with INPH is un...
Article
Full-text available
The pathophysiology of acute mountain sickness and high-altitude cerebral edema, the cerebral forms of high-altitude illness, remain uncertain and controversial. Persistently elevated or pathological fluctuations in intracranial pressure are thought to cause symptoms similar to those reported by individuals suffering cerebral forms of high-altitude...
Conference Paper
Full-text available
Over-prescription of psychotropic drugs among elderly and cognitively impaired individuals is a well-known problem. One common side effect to a majority of these drugs is an increased risk to fall. This may be fatal in a population already susceptible for falling, such as INPH patients. The objective of this study was to describe the prevalence of...
Article
Full-text available
A vascular disease could be involved in pathophysiology of normal pressure hydrocephalus (INPH). If so, there should be an association between INPH and cerebral microbleeds (CMB). This study aims to analyze if CMB are associated with INPH. In this case-control study we included 14 patients with INPH (mean age 76 years, 60 % female) and 41 healthy c...
Conference Paper
Full-text available
An emerging concept is a possible association between vascular disease/cardiovascular risk factors (CVRF) and idiopathic normal pressure hydrocephalus (INPH). However, the CVRF profile of INPH has not been investiga