Analysis of fluctuation for pixel-pair distance in co-occurrence matrix applied to ultrasonic images for diagnosis of liver fibrosis.

PURPOSE: Chronic liver disease requires careful follow-up during long-term treatment, and development of a quantitative diagnosis method for liver fibrosis based on an ultrasonic imaging system is highly desired. METHODS: Texture analysis using a co-occurrence matrix was applied to both clinical and simulated ultrasonic images of fibrotic livers. A sequence of matrices was generated for pixel-pair distance, r, and texture feature contrast was chosen to examine the response to r in combination with statistical analysis of echo amplitude distribution using a multi-Rayleigh model. RESULTS: The contrast converged with a larger value and fluctuated more significantly in response to r as fibrosis progressed in both the clinical and simulated ultrasonic images. The convergent value rapidly increased at the early stage of fibrosis, and the fluctuation became larger at the advanced stage of fibrosis. Analysis using simulated ultrasonic images with a known fibrous tissue structure theoretically clarified the relationship between contrast behavior and fibrosis progression. CONCLUSION: It was revealed that contrast convergent value and contrast fluctuation provided information on the fibrous tissue structure, and they are expected to be used for quantitative diagnosis of the degree of liver fibrosis.

Recognition of facial expressions and emotional situations in patients with dementia of the Alzheimer and vascular types.

The aim of this study was to investigate the ability of patients with dementia to recognize facial expressions and emotional situations. We evaluated 16 patients with dementia of the Alzheimer type (DAT) and 15 with vascular dementia (VD) for general cognition, discrimination of facial expressions and individual faces, and recognition of facial expressions and emotional situations. VD patients performed significantly worse than DAT patients at recognizing facial emotions, even though there was no difference between them in their general cognition and visuoperceptual abilities. There was no significant difference between them in their ability to recognize emotional situations. The results of this and past studies suggest that caregivers in nursing homes and hospitals need to be aware that VD patients lose the ability to comprehend facial expressions.

P300 amplitude over temporal regions in schizophrenia.

To examine the left temporal scalp area reductions of P300 amplitude, event-related potentials (ERPs) during a standard oddball task were recorded in 57 schizophrenic patients and 33 normal controls. The P300 amplitude at T3 was not significantly smaller than that at T4 in schizophrenic patients. In the ANOVA analysis of the P300 peak amplitude and PCA factor scores, significant lateral topographical differences in P300 were not present between patients and controls. However, in schizophrenia, patients in the low T3 P300 group were older and consuming higher doses of antipsychotic medicine than those in the high T3 P300 group, and they had relatively low P300 amplitudes and significantly delayed P300 latency, compared with those in the high T3 P300 group. These findings suggested that although the reduction in the left temporal P300 amplitude did not necessarily exist in schizophrenic patients, it may be associated with the severity of the disease process and/or impairment of cognitive function.