Decoding of visual information from human brain activity: A review of fMRI and EEG studies.

Brain is the command center for the body and contains a lot of information which can be extracted by using different non-invasive techniques. Electroencephalography (EEG), Magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) are the most common neuroimaging techniques to elicit brain behavior. By using these techniques different activity patterns can be measured within the brain to decode the content of mental processes especially the visual and auditory content. This paper discusses the models and imaging techniques used in visual decoding to investigate the different conditions of brain along with recent advancements in brain decoding. This paper concludes that it's not possible to extract all the information from the brain, however careful experimentation, interpretation and powerful statistical tools can be used with the neuroimaging techniques for better results.

Medical image visual appearance improvement using bihistogram Bezier curve contrast enhancement: data from the Osteoarthritis Initiative.

Well-defined image can assist user to identify region of interest during segmentation. However, complex medical image is usually characterized by poor tissue contrast and low background luminance. The contrast improvement can lift image visual quality, but the fundamental contrast enhancement methods often overlook the sudden jump problem. In this work, the proposed bihistogram Bezier curve contrast enhancement introduces the concept of "adequate contrast enhancement" to overcome sudden jump problem in knee magnetic resonance image. Since every image produces its own intensity distribution, the adequate contrast enhancement checks on the image's maximum intensity distortion and uses intensity discrepancy reduction to generate Bezier transform curve. The proposed method improves tissue contrast and preserves pertinent knee features without compromising natural image appearance. Besides, statistical results from Fisher's Least Significant Difference test and the Duncan test have consistently indicated that the proposed method outperforms fundamental contrast enhancement methods to exalt image visual quality. As the study is limited to relatively small image database, future works will include a larger dataset with osteoarthritic images to assess the clinical effectiveness of the proposed method to facilitate the image inspection.

MR Volumetry of Hippocampus in Normal Adult Malay of Age 50 Years Old and Above.

BACKGROUND: Hippocampal volume is affected by several psychiatric illnesses of old age, as well as by normal aging. It is important to have a normal data in a population to assist in diagnosis. The aim of this study is to determine hippocampal volume in normal Malay people aged 50 years old and older. METHODS: This was a cross-sectional study of the normal Malay population aged 50 to 77 years. We included 43 participants, representing 19 men and 24 women. Magnetic resonance imaging (MRI) was performed using a GE Signa Horizon LX 1.0 Tesla. Oblique coronal images of temporal lobes were obtained and hippocampal volumetry was done manually and normalised with intracranial volume. RESULTS: Mean right and left hippocampal volumes (HCVs) were 3.43 cm³ (SD 0.32) and 3.26 cm³ (SD 0.34), with a significant difference between them (P < 0.001). Total mean HCVs exhibited no significant difference between men and women (P = 0.234). The means of the normalised right and left HCVs were 3.42 cm³ (SD 0.31) and 3.26 cm³ (SD 0.32). CONCLUSION: The mean right and left hippocampal volumes were significantly different in this study. Men had slightly larger mean HCVs but the difference was not statistically significant. It was found that normalisation further reduces the mean volume difference between the genders.

Normalised MRI Volumetry of the Hippocampus among Normal Malay Children and Adolescents.

BACKGROUND: Magnetic resonance imaging (MRI) is a noninvasive method for determining brain morphology and volumetry. Hippocampal volume changes are observed in conjunction with several diseases. This study aimed to determine the normalised volume of the hippocampus in normal Malay children and adolescents. METHODS: This was a cross-sectional study performed from January 2009 to June 2010. Brain and temporal lobe MRI was performed for 81 healthy normal Malay individuals aged 7-18 years. Manual volumetry was performed. The hippocampal volumes were normalised with the total intracranial volume. RESULTS: The original right, left, and total hippocampal volumes (mean and standard deviation) were 3.05 (0.48) cm(3), 2.89 (0.44) cm(3), and 5.94 (0.90) cm(3), respectively. Normalised hippocampal volumes for the right, left, and total volume were 3.05 (0.41) cm(3), 2.89 (0.41) cm(3), and 5.94 (0.79) cm(3), respectively. Pearson's correlation coefficient for the right and left hippocampal volumes with intracranial volume were 0.514 and 0.413, respectively (P < 0.001). Both the original and normalised hippocampal volumes of the right hippocampus were significantly larger than those of the left (P < 0.001). CONCLUSION: This is a data set for the local Malay paediatric population. There was no significant difference between the actual and normalised values of hippocampal volume in our study.

Unifying the seeds auto-generation (SAGE) with knee cartilage segmentation framework: data from the osteoarthritis initiative.

PURPOSE: Manual segmentation is sensitive to operator bias, while semiautomatic random walks segmentation offers an intuitive approach to understand the user knowledge at the expense of large amount of user input. In this paper, we propose a novel random walks seed auto-generation (SAGE) hybrid model that is robust to interobserver error and intensive user intervention. METHODS: Knee image is first oversegmented to produce homogeneous superpixels. Then, a ranking model is developed to rank the superpixels according to their affinities to standard priors, wherein background superpixels would have lower ranking values. Finally, seed labels are generated on the background superpixel using Fuzzy C-Means method. RESULTS: SAGE has achieved better interobserver DSCs of 0.94 ± 0.029 and 0.93 ± 0.035 in healthy and OA knee segmentation, respectively. Good segmentation performance has been reported in femoral (Healthy: 0.94 ± 0.036 and OA: 0.93 ± 0.034), tibial (Healthy: 0.91 ± 0.079 and OA: 0.88 ± 0.095) and patellar (Healthy: 0.88 ± 0.10 and OA: 0.84 ± 0.094) cartilage segmentation. Besides, SAGE has demonstrated greater mean readers' time of 80 ± 19 s and 80 ± 27 s in healthy and OA knee segmentation, respectively. CONCLUSIONS: SAGE enhances the efficiency of segmentation process and attains satisfactory segmentation performance compared to manual and random walks segmentation. Future works should validate SAGE on progressive image data cohort using OA biomarkers.

Randomized Controlled Trial on the Effect of Channa striatus Extract on Measurement of the Uterus, Pulsatility Index, Resistive Index of Uterine Artery and Superficial Skin Wound Artery in Post Lower Segment Caesarean Section Women.

AIM: To compare the mean of anteroposterior (AP) measurements of the uterus in longitudinal and oblique transverse planes, and the pulsatility index (PI) and resistive index (RI) of the uterine artery and superficial skin wound artery between patients taking Channa striatus and placebo. BACKGROUND: Channa striatus, also known as haruan, is a fresh water snakehead fish consumed in many parts of Southeast Asia. Channa striatus is also normally consumed by women postpartum to promote wound healing as well as to reduce post-operative pain. METHODOLOGY: This study is a randomised, double blind, placebo-controlled study conducted in women after Lower Segment Caesarean Section (LSCS). Subjects were randomised to either a Channa striatus or a placebo group and were given a daily dosage of 500 mg of Channa striatus extract or 500 mg maltodextrin, respectively, for six weeks post LSCS. The anteroposterior measurements of the uterus in the longitudinal and oblique transverse planes, and the pulsatility index (PI) and resistive index (RI) of the uterine and superficial skin wound arteries were assessed using pelvic Gray-scale ultrasound and Doppler ultrasound at baseline (Day 3) and at two weeks, four weeks and six weeks post-operatively. RESULTS: Sixty-six subjects were randomised into the study with 33 in the Channa striatus group and 33 in the placebo group. No significant differences were detected in terms of the pulsatility index (PI) and the resistive index (RI) of the uterine and superficial skin wound arteries between the Channa striatus and placebo groups. However, in the Channa striatus group, the AP measurements of the uterus on the longitudinal and oblique transverse planes were significantly lower compared to the placebo group (p<0.05 and p<0.001, respectively). CONCLUSION: Daily intake of Channa striatus extract results in marked differences compared to placebo in terms of uterine involution and recovery in women post LSCS. TRIAL REGISTRATION: www.isrctn.com 11960786.

Interactive knee cartilage extraction using efficient segmentation software: data from the osteoarthritis initiative.

In medical image segmentation, manual segmentation is considered both labor- and time-intensive while automated segmentation often fails to segment anatomically intricate structure accordingly. Interactive segmentation can tackle shortcomings reported by previous segmentation approaches through user intervention. To better reflect user intention, development of suitable editing functions is critical. In this paper, we propose an interactive knee cartilage extraction software that covers three important features: intuitiveness, speed, and convenience. The segmentation is performed using multi-label random walks algorithm. Our segmentation software is simple to use, intuitive to normal and osteoarthritic image segmentation and efficient using only two third of manual segmentation's time. Future works will extend this software to three dimensional segmentation and quantitative analysis.