Predictors of the time to institutionalization in young- versus late-onset dementia: results from the Needs in Young Onset Dementia (NeedYD) study.

Objective: To investigate the time from symptom onset to institutionalization in persons with young-onset dementia (YOD) and compare these findings with late-onset dementia (LOD), and to determine which factors predict institutionalization in persons with YOD compared with LOD.

Design/setting: Longitudinal study of community-dwelling patients with YOD and LOD and their caregivers.

Participants: A total of 226 patients with YOD and 102 with LOD and their informal caregivers were recruited through memory clinics and health care facilities.

The 2012 revised Dutch national guidelines for the treatment of chronic hepatitis B virus infection.

In 2008, the Netherlands Association of Gastroenterologists and Hepatologists (Nederlands Vereniging van Maag-Darm-Leverartsen) published the Dutch national guidelines for the treatment of chronic hepatitis B virus infection. New insights into the treatment of chronic hepatitis B with relevance for clinical practice have been adopted in these concise, revised guidelines. The most important changes include the choice of initial antiviral therapy, licensing of tenofovir for the treatment of chronic hepatitis B and the management of antiviral resistance.

MRI-based biodistribution assessment of holmium-166 poly(L-lactic acid) microspheres after radioembolisation.

Objectives: To demonstrate the feasibility of MRI-based assessment of the intrahepatic Ho-PLLA-MS biodistribution after radioembolisation in order to estimate the absorbed radiation dose.

Methods: Fifteen patients were treated with holmium-166 ((166)Ho) poly(L-lactic acid)-loaded microspheres (Ho-PLLA-MS, mean 484 mg; range 408-593 mg) in a phase I study. Multi-echo gradient-echo MR images were acquired from which R (2) maps were constructed.

Microbrachytherapy using holmium-166 acetylacetonate microspheres: a pilot study in a spontaneous cancer animal model.

Purpose: Holmium-166 acetylacetonate microspheres ((166)Ho-AcAc-MS) are proposed as an intratumoral radioablation device. This article presents a pilot study in housecats with unresectable liver cancer. Feasibility and tolerability of intratumoral administrations of (166)Ho-AcAc-MS was investigated.

Awareness and its association with affective symptoms in young-onset and late-onset Alzheimer disease: a prospective study.

Background: It is unknown whether there are differences between young-onset dementia and late-onset dementia in awareness levels and whether awareness is differentially associated with affective symptoms in both groups. The present study assesses possible differences between young-onset (YO-AD) and late-onset Alzheimer disease (LO-AD) in awareness levels and the association between awareness and affective symptoms.

Methods: This study included 142 YO-AD and 126 LO-AD patients and their caregivers from 2 prospective studies.

Alginate-lanthanide microspheres for MRI-guided embolotherapy.

In cancer therapy, a promising treatment option to accomplish a high tumor-to-normal-tissue ratio is endovascular intervention with microsized particles, such as embolotherapy. In this study, alginate microspheres (ams) were prepared with the JetCutter technique, which is based on cutting a sodium alginate solution jet stream into small droplets of uniform size which are then cross-linked with different lanthanides or iron-III, resulting in microspheres of a predefined size which can be visualized by magnetic resonance imaging (MRI). The microspheres were investigated for their size and morphology (light microscopy and scanning electron microscopy analysis), cation content and MRI properties.

On the utility of spectroscopic imaging as a tool for generating geometrically accurate MR images and parameter maps in the presence of field inhomogeneities and chemical shift effects.

Lack of spatial accuracy is a recognized problem in magnetic resonance imaging (MRI) which severely detracts from its value as a stand-alone modality for applications that put high demands on geometric fidelity, such as radiotherapy treatment planning and stereotactic neurosurgery. In this paper, we illustrate the potential and discuss the limitations of spectroscopic imaging as a tool for generating purely phase-encoded MR images and parameter maps that preserve the geometry of an object and allow localization of object features in world coordinates. Experiments were done on a clinical system with standard facilities for imaging and spectroscopy.

Center-out radial sampling with off-resonant reconstruction for efficient and accurate localization of punctate and elongated paramagnetic structures.

Accurate localization of interventional devices, for example, needles and brachytherapy seeds, is desired for interventional procedures. MRI is usually considered unsuitable for this purpose, as the induced signal voids and signal pile-ups do not necessarily represent the exact location of the devices. Center-out radial sampling with off-resonance reception (co-RASOR) has been shown to solve this problem by repositioning the signal pile-up into the geometrical center of the interventional devices.

Alias subtraction more efficient than conventional zero-padding in the Fourier-based calculation of the susceptibility induced perturbation of the magnetic field in MR.

Forward calculation of the susceptibility induced field shift by Fourier-based procedures requires spatial zero-padding to prevent aliasing artifacts (periodic wrap-around). Padding with a factor of two gives accurate results, however, halves the maximal attainable resolution, and slows down the calculation, which may hamper the feasibility of real-time calculations. Herein is proposed to first perform the calculation at the original resolution--allowing aliasing-and to remove aliasing with an additional convolution in a lower resolution, to alleviate these restrictions regarding memory size and calculation speed, a procedure we termed "virtual" zero-padding.

Time to diagnosis in young-onset dementia as compared with late-onset dementia.

Background: The extent to which specific factors influence diagnostic delays in dementia is unclear. Therefore, the aim of the present study was to compare duration from symptom onset to diagnosis for young-onset dementia (YOD) and late-onset dementia (LOD) and to assess the effect of age at onset, type of dementia, gender, living situation, education and family history of dementia on this duration.

Method: Data on 235 YOD and 167 LOD patients collected from caregivers from two prospective cohort studies were used.

Magnetic resonance imaging-based radiation-absorbed dose estimation of 166Ho microspheres in liver radioembolization.

Purpose: To investigate the potential of magnetic resonance imaging (MRI) for accurate assessment of the three-dimensional (166)Ho activity distribution to estimate radiation-absorbed dose distributions in (166)Ho-loaded poly (L-lactic acid) microsphere ((166)Ho-PLLA-MS) liver radioembolization.

Methods And Materials: MRI, computed tomography (CT), and single photon emission CT (SPECT) experiments were conducted on an anthropomorphic gel phantom with tumor-simulating gel samples and on an excised human tumor-bearing liver, both containing known amounts of (166)Ho-PLLA-MS. Three-dimensional radiation-absorbed dose distributions were estimated at the voxel level by convolving the (166)Ho activity distribution, derived from quantitative MRI data, with a (166)Ho dose point-kernel generated by MCNP (Monte Carlo N-Particle transport code) and from Medical Internal Radiation Dose Pamphlet 17.

Selective depiction of susceptibility transitions using Laplace-filtered phase maps.

In this work, we aim to demonstrate the ability of Laplace-filtered three-dimensional (3D) phase maps to selectively depict the susceptibility transitions in an object. To realize this goal, it is first shown that both the Laplace derivative of the z component of the static magnetic field in an object and the Laplacian of the corresponding phase distribution may be expected to be zero in regions of constant or linearly varying susceptibility and to be nonzero when there is an abrupt change in susceptibility, for instance, at a single point, a ridge, an interface, an edge or a boundary. Next, a method is presented by which the Laplace derivative of a 3D phase map can be directly extracted from the complex data, without the need for phase unwrapping or subtraction of a reference image.

Characterizing the protocol for early modified constraint-induced movement therapy in the EXPLICIT-stroke trial.

Constraint-induced movement therapy (CIMT) is a commonly used rehabilitation intervention to improve upper limb function after stroke. CIMT was originally developed for patients with a chronic upper limb paresis. Although there are indications that exercise interventions should start as early as possible after stroke, only a few randomized controlled trials have been published on either CIMT or modified forms of CIMT (mCIMT) during the acute phase after stroke.

Towards inherently distortion-free MR images for image-guided radiotherapy on an MRI accelerator.

In MR-guided interventions, it is mandatory to establish a solid relationship between the imaging coordinate system and world coordinates. This is particularly important in image-guided radiotherapy (IGRT) on an MRI accelerator, as the interaction of matter with γ-radiation cannot be visualized. In conventional acquisitions, off-resonance effects cause discrepancies between coordinate systems.

Quantification of holmium-166 loaded microspheres: estimating high local concentrations using a conventional multiple gradient echo sequence with S₀-fitting.

Purpose: To provide a best estimate of the R 2* value and hence of the local concentration of highly paramagnetic holmium-166 loaded microspheres (HoMS) in voxels for which R 2* cannot be characterized by conventional fitting of multigradient echo (MGE) data because of fast signal decay due to high local concentrations.

Materials And Methods: A postprocessing method, S(0)-fitting, was implemented in a conventional R 2* fitting method that is used for quantification of HoMS. S(0)-fitting incorporates the estimated initial amplitude of the free induction decay (FID) curve, S(0), of neighboring voxels into the fitting procedure for voxels for which the conventional algorithm failed.

Correction of gradient echo images for first and second order macroscopic signal dephasing using phase derivative mapping.

Gradient echo techniques are often hampered by signal dephasing due to macroscopic phase perturbations because of system imperfections (shimming) or object induced perturbations of the magnetic field (hemorrhagic lesions, calcified tissue, air-tissue interfaces). Many techniques have been proposed to reduce the effects of macroscopic phase variations. Among these techniques are tuned pulse sequences, fitting techniques and reconstruction algorithms.

Radioactive holmium acetylacetonate microspheres for interstitial microbrachytherapy: an in vitro and in vivo stability study.

Purpose: The clinical application of holmium acetylacetonate microspheres (HoAcAcMS) for the intratumoral radionuclide treatment of solid malignancies requires a thorough understanding of their stability. Therefore, an in vitro and an in vivo stability study with HoAcAcMS was conducted.

Methods: HoAcAcMS, before and after neutron irradiation, were incubated in a phosphate buffer at 37°C for 6 months.

MRT letter: Contrast-enhanced computed tomographic imaging of soft callus formation in fracture healing.

Formation of a cartilaginous soft callus at the site of a bone fracture is a pivotal stage in the healing process. Noninvasive, or even nondestructive, imaging of soft callus formation can be an important tool in experimental and pre-clinical studies of fracture repair. However, the low X-ray attenuation of cartilage renders the soft callus nearly invisible in radiographs.

Caregivers' perspectives on the pre-diagnostic period in early onset dementia: a long and winding road.

Background: Recognizing and diagnosing early onset dementia (EOD) can be complex and often takes longer than for late onset dementia. The objectives of this study are to investigate the barriers to diagnosis and to develop a typology of the diagnosis pathway for EOD caregivers.

Methods: Semi-structured interviews with 92 EOD caregivers were analyzed using constant comparative analysis and grounded theory.

Use of multispectral MRI to monitor aneurysm sac contents after endovascular abdominal aortic aneurysm repair.

Purpose: To validate a newly developed semi-automatic multispectral magnetic resonance imaging (MRI) tool for quantitatively monitoring aneurysm sac contents in patients after endovascular aneurysm repair (EVAR).

Methods: MRI studies from 24 EVAR patients were retrospectively analyzed. The precontrast T₁-weighted and T₂-weighted and the postcontrast T₁-weighted images were displayed simultaneously.

Temperature dependence of the magnetic volume susceptibility of human breast fat tissue: an NMR study.

Object: Proton resonance frequency shift (PRFS)-based MR thermometry (MRT) is hampered by heat-induced susceptibility changes when applied in tissues containing fat, e.g., the human breast.

A wolf in sheep's clothing.

Carcinoid tumours are often difficult to diagnose because of non-specific symptoms, mimicking those of irritable bowel disease of Crohn's disease. The authors describe a 57-year-old patient with clinical and radiological features, suggestive of Crohn's disease, in whom the diagnosis was proved to be a carcinoid tumour involving the terminal ileum. This case report illustrates that ileal carcinoid should be considered in the differential diagnosis of Crohn's disease, particularly in older patients.

Needs in early onset dementia: A qualitative case from the NeedYD study.

Objectives: The aim was to explore the experiences of a caregiver of a patient with early onset dementia (EOD) and the needs of patient and caregiver.

Methods: A single case study design was used to explore (1) unmet needs of patient and caregiver and (2) caregiver's experiences of transitions in care and health care services. A qualitative analysis was used to examine the data.