• Journal of Korea Multimedia Society
• /
• v.21 no.5
• /
• pp.609-616
• /
• 2018

In this paper, we designed a multimodal bio-signal measurement system to observe changes in the brain nervous system and vascular system during sleep. Changes in the nervous system and the cerebral blood flow system in the brain during sleep induce a unique correlation between the changes in the nervous system and the blood flow system. Therefore, it is necessary to simultaneously observe changes in the brain nervous system and changes in the blood flow system to observe the sleep state. To measure the change of the nervous system, EEG, EOG and EMG signal used for the sleep stage analysis were designed. We designed a system for measuring cerebral blood flow changes using functional near-infrared spectroscopy. Among the various imaging methods to measure blood flow and metabolism, it is easy to measure simultaneously with EEG signal and it can be easily designed for miniaturization of equipment. The sleep stage was analyzed by the measured data, and the change of the cerebral blood flow was confirmed by the change of the sleep stage.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.1
• /
• pp.42-50
• /
• 2017

A cerebral aneurysm is a ballooning arising from a weakened area in the wall of a blood vessel in the brain. In this study, the flow analysis of the blood vessel, including the cerebral aneurysm and the stent, was conducted to investigate the effect of the stent shape on reduction of blood flowing into the cerebral aneurysm. We used the Carreau model to describe Non-Newtonian behaviors of blood flow. Two kinds of stents, which had different cross angles were modelled by the commercial CAD program and the geometries of those stents were reflected in the analysis domain of the blood vessel. From the results of the flow analysis, we found that the blood flowing into the cerebral aneurysm was decreased as the cross angle of the stent was decreased.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.11
• /
• pp.5311-5316
• /
• 2012

Single Photon Emission Computed tomography(SPECT) was performed on 13 healthy adults (average age: 39) to investigate the changes of cerebral blood flow according to brain imaging analysis algorithm. The acquired images were filtered and reconstructed through Filtered Back Projection (FBP) and Ordered Subset Expectation Maximization (OSEM). The brain distribution data of radiopharmaceuticals were compared using Statistical Parametric Mapping (SPM), and the changes of blood flow was expressed in Cluster. As a result, uptake rate was increased in Sub-gyral, Sub-Lobar, Extra-Nuclear, Limbic lobe and Cingulate Gyrus, while uptake rate was decreased in Middle frontal gyrus, Inferior Frontal Gyrus and Precentral Gyrus. The discriminable SPM was shown according to cerebral blood flows in Cluster by the reconstruction algorithm.

• Journal of radiological science and technology
• /
• v.27 no.3
• /
• pp.31-41
• /
• 2004

Attention deficit hyperactivity disorder(ADHD)is one of the most common psychiatric disorders in childhood, especially school age children and persisting into adult. ADHD is affected 7.6% in our children, Korea. and persisting into $15{\sim}20%$ in adult. And it is characterized by hyperactivity, inattention and impulsivity. Brain imaging is one of way to diagnosis for ADHD. Brain imaging studies may be provide information two types - structural and functional imaging. Structural and functional images of the brain play an important role in management of neurologic and psyciatric disorders. Brain SPECT, with perfusion imaging radiopharmaceuticals is one of the appropriate test to diagnosis of neurologic and psychiatric diseases. Ther are a few studies about separated analysis between boys and girls ADHD SPECT brain images. Selection of Probability level(P-value) is very important to determind the abnormalities when analysis a data by SPM. SPM is a statistical method used for image analysis and determine statistical different between two groups-normal and ADHD. Commonly used P-value is P<0.05 in statistical analysis. The purpose of this study is to evaluation of blood flow clusters distribution, between boys and girls ADHD. The number of normal boys are 8(6-7y, average : $9.6{\pm}3.9y$) and 51(4-11y, average : $9.0{\pm}2.4$) ADHD patients, and normal girls are 4(6-12y, average : $9{\pm}2.4y$) and 13(2-13y, average $10{\pm}3.5y$) ADHD patiens. Blood flow tracer $^{99m}Tc-ethylcysteinate$ dimer(ECD) injected as rCBF agent and take blood flow images after 30 min. during sleeping by SPECT camera. The anatomical region of hyperperfusion of rCBF in boys ADHD group is posterior cingulate gyrus and hyperperfusion rate is 15.39-15.77% according to p-value. And girls ADHD group appears at posterior cerebellum, Lt. cerbral limbic lobe and Lt. Rt. cerebral temporal lobe. These areas hyperperfusion rate are 24.68-31.25%. Hypoperfusion areas in boys ADHD,s brain are Lt. cerebral insular gyrus, Lt. Rt. frontal lobe and mid-prefrontal lobe, these areas decresed blood flow as 15.21-15.64%. Girls ADHD decreased blood flow regions are Lt. cerebral insular gyrus, Lt. cerebral frontal and temporal lobe, Lt. Rt. lentiform nucleus and Lt. parietal lobe. And hypoperfusion rate is 30.57-30.85% in girls ADHD. The girls ADHD group's perfusion rate is more variable than boys. The studies about rCBF in ADHD, should be separate with boys and girls.

• Current Optics and Photonics
• /
• v.1 no.5
• /
• pp.433-439
• /
• 2017

The rodent model has been used frequently to understand stroke pathophysiology, due to its low cost and the large spectrum of genetic strains available. Here, we present a diffuse speckle contrast analysis system (DSCA) with a $1{\times}2$ optical switch that was used to non-invasively assess cerebral blood flow (CBF) changes in the rat during intraluminal suturing for middle cerebral artery occlusion (MCAO) surgery. The blood flow index (BFI) in the left hemisphere was lower than that in the right hemisphere because the left middle cerebral artery was occluded. Furthermore, the performance of the DSCA system was compared with that of commercial laser Doppler flowmetry. The changes in the BFI measured by the two systems were correlated strongly. The DSCA system was less sensitive to motion artifacts and able to measure relatively deep tissue flow in the rat's brain. In conclusion, the DSCA system secured CBF monitoring during surgery in a rodent model without craniotomy.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.341-344
• /
• 2002

Neurodegenerative disorders, like Alzheimer's disease, are often accompanied by reduced brain perfusion (cerebral blood flow). Using the intrinsic magnetic properties of water, arterial spin labeling magnetic resonance imaging (ASLMRI) can map brain perfusion without injection of radioactive tracers or contrast agents. However, accuracy in measuring perfusion with ASL-MRI can be limited because of contributions to the signal from stationary spins and because of signal modulations due to transient magnetic field effects. The goal was to optimize ASL-MRI for perfusion measurements in the aging human brain, including brains with Alzheimer's disease. A new ASL-MRI sequence was designed and evaluated on phantom and humans. Image texture analysis was performed to test quantitatively improvements. Compared to other ASL-MRI methods, the newly designed sequence provided improved signal to noise ratio improved signal uniformity across slices, and thus, increased measurement reliability. This new ASL-MRI sequence should therefore provide improved measurements of regional changes of brain perfusion in normal aging and neurodegenerative disorders.

• Journal of Korean Neurosurgical Society
• /
• v.56 no.3
• /
• pp.261-264
• /
• 2014

We report perfusion weighted imaging (PWI) findings of nonenhanced anaplastic astrocytoma in a 30-year-old woman. Brain magnetic resonance imaging showed a nonenhanced brain tumor with mild peritumoral edema on the right medial frontal lobe and right genu of corpus callosum, suggesting a low-grade glioma. However, PWI showed increased relative cerebral blood volume, relative cerebral blood flow, and permeability of nonenhanced brain tumor compared with contralateral normal brain parenchyma, suggesting a high-grade glioma. After surgery, final histopathological analysis revealed World Health Organization grade III anaplastic astrocytoma. This case demonstrates the importance of PWI for preoperative evaluation of nonenhanced brain tumors.

• The Korean Journal of Nuclear Medicine
• /
• v.37 no.1
• /
• pp.63-72
• /
• 2003

Functional MRI (fMRI) provides an indirect mapping of cerebral activity, based on the detection of the local blood flow and oxygenation changes following neuronal activity (Blood Oxygenation Level Dependent). fMRI allows us to study noninvasively the normal and pathological aspects of functional cortical organization. Each fMRI study compares two different states of activity. Echo-Planar Imaging is the technique that makes it possible to study the whole brain at a rapid pace. Activation maps are calculated from a statistical analysis of the local signal changes. fMRI is now becoming an essential tool in the neurofunctional evaluation of normal volunteers and many neurological patients as well as the reference method to image normal or pathologic functional brain organization.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.721-722
• /
• 2002

The aim of this work is to analyze changes in cerebral hemodynamics and intracranial pressure mediated by cerebral blood flow challenges in patients with acute heart arrest. Lumped parameter model with feedback mechanism is utilized to simulate the hemodynamics of brain blood flow in case 40 min T-PLS operation is applied to patients of cardiac arrest. Numerical solutions show that cerebral blood flow and perfusion pressure in patients of cardiac arrest are sharply recovered in the initial state of T-PLS operation.

• The Korean Journal of Nuclear Medicine
• /
• v.36 no.3
• /
• pp.166-176
• /
• 2002

Purpose: The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of $^{99m}Tc-HMPAO$ (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. Materials and Methods: The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and $^{99m}Tc-HMPAO$ SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the legion of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). Results: The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was $32.50{\pm}5.67%$. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Conclusion: Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.