Early-phase amyloid PET reproduces metabolic signatures of cognitive decline in Parkinson's disease.

Introduction: Recent work suggests that amyloid beta (Aβ) positron emission tomography (PET) tracer uptake shortly after injection ("early phase") reflects brain metabolism and perfusion. We assessed this modality in a predominantly amyloid-negative neurodegenerative condition, Parkinson's disease (PD), and hypothesized that early-phase F-florbetaben (eFBB) uptake would reproduce characteristic hypometabolism and hypoperfusion patterns associated with cognitive decline in PD.

Methods: One hundred fifteen PD patients across the spectrum of cognitive impairment underwent dual-phase Aβ PET, structural and arterial spin labeling (ASL) magnetic resonance imaging (MRI), and neuropsychological assessments.

Evaluation of deep-learning TSE images in clinical musculoskeletal imaging.

In this study, we compared the fat-saturated (FS) and non-FS turbo spin echo (TSE) magnetic resonance imaging knee sequences reconstructed conventionally (conventional-TSE) against a deep learning-based reconstruction of accelerated TSE (DL-TSE) scans. A total of 232 conventional-TSE and DL-TSE image pairs were acquired for comparison. For each consenting patient, one of the clinically acquired conventional-TSE proton density-weighted sequences in the sagittal or coronal planes (FS and non-FS), or in the axial plane (non-FS), was repeated using a research DL-TSE sequence.

Magnetic resonance imaging of breast implants: Optimizing tissue contrast.

Introduction: Patients with breast implants need to undergo regular screening MRI procedures. One of the key requirements of this screening scan is the ability to suppress one or more tissues (water, fat, or silicone) simultaneously. However, the presence of "foreign" implants within the breast biological space affects the MRI scanner's normal operating mode.

Test-retest reliability and sample size estimates after MRI scanner relocation.

Objective: Many factors can contribute to the reliability and robustness of MRI-derived metrics. In this study, we assessed the reliability and reproducibility of three MRI modalities after an MRI scanner was relocated to a new hospital facility.

Methods: Twenty healthy volunteers (12 females, mean age (standard deviation) ​= ​41 (11) years, age range [25-66]) completed three MRI sessions.

Beta Amyloid Deposition Is Not Associated With Cognitive Impairment in Parkinson's Disease.

The extent to which Alzheimer neuropathology, particularly the accumulation of misfolded beta-amyloid, contributes to cognitive decline and dementia in Parkinson's disease (PD) is unresolved. Here, we used Florbetaben PET imaging to test for any association between cerebral amyloid deposition and cognitive impairment in PD, in a sample enriched for cases with mild cognitive impairment. This cross-sectional study used Movement Disorders Society level II criteria to classify 115 participants with PD as having normal cognition (PDN, = 23), mild cognitive impairment (PD-MCI, = 76), or dementia (PDD, = 16).

Tracking Parkinson's Disease over One Year with Multimodal Magnetic Resonance Imaging in a Group of Older Patients with Moderate Disease.

Background & Objectives: Cross-sectional magnetic resonance imaging (MRI) suggests that Parkinson's disease (PD) is associated with changes in cerebral tissue volume, diffusion tensor imaging metrics, and perfusion values. Here, we performed a longitudinal multimodal MRI study--including structural, diffusion tensor imaging (DTI), and perfusion MRI--to investigate progressive brain changes over one year in a group of older PD patients at a moderate stage of disease.

Methods: Twenty-three non-demented PD (mean age (SD) = 69.

Metabolite ratios in the posterior cingulate cortex do not track cognitive decline in Parkinson's disease in a clinical setting.

Introduction: Parkinson's Disease (PD) is classified as a motor disorder, but most patients develop cognitive impairment, and eventual dementia (PDD). Predictive neurobiomarkers may be useful in the identification of those patients at imminent risk of PDD. Given the compromised cerebral integrity in PDD, we investigated whether brain metabolites track disease progression over time.

Comparing cerebral perfusion in Alzheimer's disease and Parkinson's disease dementia: an ASL-MRI study.

Emerging evidence suggests that Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) share neurodegenerative mechanisms. We sought to directly compare cerebral perfusion in these two conditions using arterial spin labeling magnetic resonance imaging (ASL-MRI). In total, 17 AD, 20 PDD, and 37 matched healthy controls completed ASL and structural MRI, and comprehensive neuropsychological testing.

White matter microstructure deteriorates across cognitive stages in Parkinson disease.

Objectives: To characterize different stages of Parkinson disease (PD)-related cognitive decline using diffusion tensor imaging (DTI) and investigate potential relationships between cognition and microstructural integrity of primary white matter tracts.

Methods: Movement Disorder Society criteria were used to classify 109 patients with PD as having normal cognition (PD-N, n = 63), mild cognitive impairment (PD-MCI, n = 28), or dementia (PD-D, n = 18), and were compared with 32 matched controls. DTI indices were assessed across groups using tract-based spatial statistics, and multiple regression was used to assess association with cognitive and clinical measures.

Reduced striatal volumes in Parkinson's disease: a magnetic resonance imaging study.

Background: The presence and extent of structural changes in the brain as a consequence of Parkinson's disease (PD) is still poorly understood.

Methods: High-resolution 3-tesla T1-weighted structural magnetic resonance images in sixty-five PD and 27 age-matched healthy control participants were examined. Putamen, caudate, and intracranial volumes were manually traced in the axial plane of 3D reconstructed images.

Grey matter atrophy in cognitively impaired Parkinson's disease.

Objective: Mild cognitive impairment and dementia are common non-motor features of Parkinson's disease (PD). The aim of this study was to characterise grey matter changes associated with clearly defined stages of cognitive impairment in PD using structural MRI.

Methods: 96 PD subjects were classified using detailed cognitive testing as PD with normal cognition (PD-N, n=57), PD with mild cognitive impairment (PD-MCI, n=23) or PD with dementia (PD-D, n=16); 34 controls matched for mean age and sex ratio also participated.