Mirror writing and cortical hypometabolism in Parkinson's disease.

Mirror writing (MW) is the production of individual letters, words, or word strings in the reverse direction. Parkinson's disease (PD) is a progressive neurodegenerative disorder, and high MW rates have been reported in patients with PD. Thus, the present study sought to identify the factors that cause MW in patients with PD.

Impaired perception of illusory contours and cortical hypometabolism in patients with Parkinson's disease.

Neuroimaging evidence suggests that areas of the higher-order visual cortex, including the lateral occipital complex (LOC), are engaged in the perception of illusory contours; however, these findings remain unsubstantiated by human lesion data. Therefore, we assessed the presentation time necessary to perceive two types of illusory contours formed by Kanizsa figures or aligned line ends in patients with Parkinson's disease (PD). Additionally, we used F-fluorodeoxyglucose positron emission tomography (FDG-PET) to measure regional cerebral glucose metabolism in PD patients.

Neural substrates underlying progressive micrographia in Parkinson's disease.

Introduction: The neural substrates associated with the development of micrographia remain unknown. We aimed to elucidate the neural substrates underlying micrographia in Parkinson's disease (PD) patients.

Methods: Forty PD patients and 20 healthy controls underwent handwriting tests that involved free writing and copying.

Clinical and Cerebral Metabolic Changes in Parkinson's Disease With Basal Forebrain Atrophy.

Background: Cholinergic dysfunction plays a key role in cognitive dysfunction in Parkinson's disease (PD). Recent studies revealed that atrophy in the nucleus basalis of Meynert (NBM), the largest cholinergic nucleus in the basal forebrain, heralds cognitive decline in PD. Despite clinical importance of NBM atrophy in PD, clinical and radiological correlates of NBM atrophy remains to be elucidated.

Comparison of Count Normalization Methods for Statistical Parametric Mapping Analysis Using a Digital Brain Phantom Obtained from Fluorodeoxyglucose-positron Emission Tomography.

Objectives: Alternative normalization methods were proposed to solve the biased information of SPM in the study of neurodegenerative disease. The objective of this study was to determine the most suitable count normalization method for SPM analysis of a neurodegenerative disease based on the results of different count normalization methods applied on a prepared digital phantom similar to one obtained using fluorodeoxyglucose-positron emission tomography (FDG-PET) data of a brain with a known neurodegenerative condition.

Methods: Digital brain phantoms, mimicking mild and intermediate neurodegenerative disease conditions, were prepared from the FDG-PET data of 11 healthy subjects.

A quantitative morphological analysis of three-dimensional CT coxal bone images of contemporary Japanese using homologous models for sex and age estimation.

Sexual dimorphisms and age-dependent morphological features of the human coxal bone were quantitatively analyzed using homologous models created from three-dimensional (3D) computed tomography images of the pelvis (male: 514 samples, female: 388 samples, age 16-100). Bilateral average coxal images of each sex and age decade were generated separately through principle component analyses (PCA). By measuring average point-to-point distances of 8472 corresponding points (average corresponding point differences [ACPDs]) between each homologous coxal image and the average images, the sex of more than 93% of the samples was correctly assigned.

Defining visual illusions in Parkinson's disease: Kinetopsia and object misidentification illusions.

Objective: To identify the phenomenological features and neural correlates of visual illusions in Parkinson's disease (PD).

Methods: Ninety-three patients with PD were assessed via questionnaires regarding visual illusions and behavioral symptoms, and neuropsychological tests, motor assessments and 18-F fluorodeoxyglucose-positron emission tomography (FDG-PET) were performed. The relationship between visual illusions or hallucinations and regional cerebral glucose metabolism was investigated using partial least squares (PLS) correlation and conventional mass-univariate analyses.

Investigation of fMRI Analysis Method to Visualize the Difference in the Brain Activation Timing.

Rationale And Objectives: In general functional magnetic resonance imaging (fMRI) analysis, the task onset time of the statistical model is typically set according to the timing of stimulation. In this study, using a high temporal resolution fMRI data, we examined the way of dynamically visualizing the difference in the activation timing between the brain activation areas by analyzing the task onset time of the statistical model shifted from the actual stimulation timing.

Materials And Methods: fMRI data with high temporal resolution was acquired using 3 T magnetic resonance imaging for 10 right-handed healthy volunteers.

[Motion-frozen Imaging by Gated Myocardial Perfusion Single Photon Emission Computed Tomography Using Multi-focus Fan Beam Collimator in Thallium-201 Study].

Purpose: This study aimed to evaluate the statistical noise of motion-frozen (MF) image generated by gated myocardial perfusion single photon emission computed tomography (SPECT) imaging using IQ · SPECT and to determine the optimal acquisition and reconstruction parameters for MF image using IQ · SPECT.

Methods: A movement cardiac phantom and static cardiac phantom were used to acquire the MF images. The acquisition times used were different in 8 and 16 frames per R-R interval, and varying reconstruction parameters (subset and iteration) were used.

Longitudinal study of cognitive and cerebral metabolic changes in Parkinson's disease.

Objective: To investigate the cortical metabolic alterations that precedes longitudinal cognitive decline in Parkinson's disease (PD).

Methods: We analyzed the data of 46 PD patients who did not have dementia at baseline and completed 3-year follow-up. Based on the results of general cognitive, memory and visuospatial tests, patients were classified into cognitively normal PD (PD-CogNL), PD with mild cognitive impairment (PD-MCI), and PD dementia (PDD).

A Case Report of Postmortem Radiography of Acute, Fatal Abdominal Distension After Binge Eating.

This case report describes a woman who developed fatal gastric dilatation after binge eating. She called an ambulance because of stomach pain. When she arrived at the hospital, she did not look seriously ill.

Rectal temperature-based death time estimation in infants.

In determining the time of death in infants based on rectal temperature, the same methods used in adults are generally used. However, whether the methods for adults are suitable for infants is unclear. In this study, we examined the following 3 methods in 20 infant death cases: computer simulation of rectal temperature based on the infinite cylinder model (Ohno's method), computer-based double exponential approximation based on Marshall and Hoare's double exponential model with Henssge's parameter determination (Henssge's method), and computer-based collinear approximation based on extrapolation of the rectal temperature curve (collinear approximation).

A case of fatal sigmoid volvulus visualized on postmortem radiography: The importance of image optimization with multidetector computed tomography.

This report describes the case of a man who developed fatal sigmoid volvulus that was identified on postmortem radiography before forensic autopsy. Postmortem radiography is useful for visualizing the body prior to autopsy. We discuss postmortem multidetector computed tomography that was tailored for optimum image quality to allow reconstruction of the fatal findings in multiple axes and in three dimensions, helping to pinpoint the anatomical sites of interest.

Usefulness and limitations of postmortem computed tomography in forensic analysis of gunshot injuries: Three case reports.

Gunshot injury has always been an important field of investigation in postmortem forensic radiology. The localization and retrieval of the bullet and of potentially important fragments are vital to these cases. Using postmortem multidetector-row computed tomography (MDCT) prior to forensic autopsy, we sought to illustrate the importance of this modality in the noninvasive characterization of gunshot wounds.

Distinction between saltwater drowning and freshwater drowning by assessment of sinus fluid on post-mortem computed tomography.

Objective: To evaluate the difference in sinus fluid volume and density between saltwater and freshwater drowning and diagnose saltwater drowning in distinction from freshwater drowning.

Methods: Ninety-three drowning cases (22 saltwater and 71 freshwater) were retrospectively investigated; all had undergone post-mortem CT and forensic autopsy. Sinus fluid volume and density were calculated using a 3D-DICOM workstation, and differences were evaluated.

Pareidolia in Parkinson's disease without dementia: A positron emission tomography study.

Background: Pareidolia, which is a particular type of complex visual illusion, has been reported to be a phenomenon analogous to visual hallucinations in patients with dementia with Lewy bodies. However, whether pareidolia is observed in Parkinson's disease (PD) or whether there are common underlying mechanisms of these two types of visual misperceptions remains to be elucidated.

Methods: A test to evoke pareidolia, the Pareidolia test, was administered to 53 patients with PD without dementia and 24 healthy controls.

Post-mortem computed tomography findings of the lungs: Retrospective review and comparison with autopsy results of 30 infant cases.

Objectives: Infant cases frequently show a diffuse increase in the concentration of lung fields on post-mortem computed tomography (PMCT). However, the lungs often show simply atelectasis at autopsy in the absence of any other abnormal changes. Thus, we retrospectively reviewed the PMCT findings of lungs following sudden infant death and correlated them with the autopsy results.