Classifying Schizotypy Using an Audiovisual Emotion Perception Test and Scalp Electroencephalography.

Schizotypy refers to the personality trait of experiencing "psychotic" symptoms and can be regarded as a predisposition of schizophrenia-spectrum psychopathology (Raine, 1991). Cumulative evidence has revealed that individuals with schizotypy, as well as schizophrenia patients, have emotional processing deficits. In the present study, we investigated multimodal emotion perception in schizotypy and implemented the machine learning technique to find out whether a schizotypy group (ST) is distinguishable from a control group (NC), using electroencephalogram (EEG) signals. Forty-five subjects (30 ST and 15 NC) were divided into two groups based on their scores on a Schizotypal Personality Questionnaire. All participants performed an audiovisual emotion perception test while EEG was recorded. After the preprocessing stage, the discriminatory features were extracted using a mean subsampling technique. For an accurate estimation of covariance matrices, the shrinkage linear discriminant algorithm was used. The classification attained over 98% accuracy and zero rate of false-positive results. This method may have important clinical implications in discriminating those among the general population who have a subtle risk for schizotypy, requiring intervention in advance.

DICOM-based intravascular ultrasound signal intensity analysis: an Echoplaque Medical Imaging Bench study.

BACKGROUND: Most intravascular ultrasound (IVUS) data are stored digitally using the Digital Imaging and Communications in Medicine (DICOM) standard. This allows random access to studies and improves on the major limitation of conventional grayscale IVUS. METHODS: We harvested 129 coronary arteries from 43 autopsied cases. Grayscale IVUS and virtual histology-IVUS imaging were performed beginning 30 mm distal to the ostium of each coronary artery. Grayscale IVUS was processed; and the signal intensity was determined from DICOM-stored images using a new Medical Imaging Bench system (Echoplaque-MIB). We compared 436 regions of interest. The accuracy rate was expressed using the interpolation method and 95% confidence interval (CI). RESULTS: Patients' mean age was 49±9 years and 82% were men. Four patients succumbed to sudden cardiac death and 39 to noncardiac death. Grayscale IVUS signal intensity of dense calcium was 215±21.1 (95% CI: 207-223), that of fibrotic plaque was 75±17.8 (95% CI: 72-79), and that of fibrofatty plaque was 55±11.3 (95% CI: 52-59); however, the signal intensity of the necrotic core was between fibrotic plaque and dense calcium of 161±27.4 (95% CI: 153-168). Using the interpolation method, the cutoff values were as follows: fibrofatty plaque 0-65, fibrotic plaque 66-105, necrotic core 106-187, and dense calcium of at least 188. Overall, MIB grayscale had a 78.1% sensitivity and a 91.9% specificity versus histopathology. CONCLUSION: Plaque characterization using DICOM-based grayscale IVUS signal intensity analysis may improve on the major limitation of conventional grayscale IVUS: its inability to assess plaque composition.

Atherosclerotic progression attenuates the expression of Nogo-B in autopsied coronary artery: pathology and virtual histology intravascular ultrasound analysis.

The relation of Nogo-B to atherosclerotic plaque progression is not well understood. Thus, the purpose of this study was to assess the expression of Nogo-B in fibroatheromas (FA) of different stages, classified using virtual histology intravascular ultrasound (VH-IVUS) analysis in 19 autopsied cases of non-sudden cardiac death. VH-IVUS imaging analysis was performed 30 mm from the ostium of each coronary artery. VH-IVUS revealed 11 early FAs (34.5+/-8.3 yr), 12 late FAs (42.6+/-16.6 yr), 8 thick-cap FAs (TkCFAs) (46.4+/-11.1 yr), and 6 thin-cap FAs (TCFAs) (51.8+/-6.8 yr). TkCFAs and TCFAs were defined as advanced FA. FA progression advanced with age (P=0.04). VH-IVUS analysis of small, early FAs showed smaller necrotic cores and relatively less calcium compared to more advanced FAs with large necrotic cores (P<0.001). Histopathology and immunohistochemical stains demonstrated that early or late FAs had smaller necrotic cores, less empty space of decalcification, and greater Nogo-B expression compared to advanced FAs (vs. early FA, P=0.013; vs. late FA, P=0.008, respectively). These findings suggest that FA progression is inversely associated with Nogo-B expression. Local reduction of Nogo-B may contribute to plaque formation and/or instability.