Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
Add filters








Year range
1.
Article in English | WPRIM | ID: wpr-902477

ABSTRACT

Objective@#Chemical exchange-dependent saturation transfer (CEST) MRI is sensitive for detecting solid-like proteins and may detect changes in the levels of mobile proteins and peptides in tissues. The objective of this study was to evaluate the characteristics of chemical exchange proton pools using the CEST MRI technique in patients with dementia. @*Materials and Methods@#Our institutional review board approved this cross-sectional prospective study and informed consent was obtained from all participants. This study included 41 subjects (19 with dementia and 22 without dementia). Complete CEST data of the brain were obtained using a three-dimensional gradient and spin-echo sequence to map CEST indices, such as amide, amine, hydroxyl, and magnetization transfer ratio asymmetry (MTR asym) values, using six-pool Lorentzian fitting. Statistical analyses of CEST indices were performed to evaluate group comparisons, their correlations with gray matter volume (GMV) and Mini-Mental State Examination (MMSE) scores, and receiver operating characteristic (ROC) curves. @*Results@#Amine signals (0.029 for non-dementia, 0.046 for dementia, p = 0.011 at hippocampus) and MTR asym values at 3 ppm (0.748 for non-dementia, 1.138 for dementia, p = 0.022 at hippocampus), and 3.5 ppm (0.463 for non-dementia, 0.875 for dementia, p = 0.029 at hippocampus) were significantly higher in the dementia group than in the non-dementia group. Most CEST indices were not significantly correlated with GMV; however, except amide, most indices were significantly correlated with the MMSE scores. The classification power of most CEST indices was lower than that of GMV but adding one of the CEST indices in GMV improved the classification between the subject groups. The largest improvement was seen in the MTR asym values at 2 ppm in the anterior cingulate (area under the ROC curve = 0.981), with a sensitivity of 100 and a specificity of 90.91. @*Conclusion@#CEST MRI potentially allows noninvasive image alterations in the Alzheimer’s disease brain without injecting isotopes for monitoring different disease states and may provide a new imaging biomarker in the future.

2.
Article in English | WPRIM | ID: wpr-894773

ABSTRACT

Objective@#Chemical exchange-dependent saturation transfer (CEST) MRI is sensitive for detecting solid-like proteins and may detect changes in the levels of mobile proteins and peptides in tissues. The objective of this study was to evaluate the characteristics of chemical exchange proton pools using the CEST MRI technique in patients with dementia. @*Materials and Methods@#Our institutional review board approved this cross-sectional prospective study and informed consent was obtained from all participants. This study included 41 subjects (19 with dementia and 22 without dementia). Complete CEST data of the brain were obtained using a three-dimensional gradient and spin-echo sequence to map CEST indices, such as amide, amine, hydroxyl, and magnetization transfer ratio asymmetry (MTR asym) values, using six-pool Lorentzian fitting. Statistical analyses of CEST indices were performed to evaluate group comparisons, their correlations with gray matter volume (GMV) and Mini-Mental State Examination (MMSE) scores, and receiver operating characteristic (ROC) curves. @*Results@#Amine signals (0.029 for non-dementia, 0.046 for dementia, p = 0.011 at hippocampus) and MTR asym values at 3 ppm (0.748 for non-dementia, 1.138 for dementia, p = 0.022 at hippocampus), and 3.5 ppm (0.463 for non-dementia, 0.875 for dementia, p = 0.029 at hippocampus) were significantly higher in the dementia group than in the non-dementia group. Most CEST indices were not significantly correlated with GMV; however, except amide, most indices were significantly correlated with the MMSE scores. The classification power of most CEST indices was lower than that of GMV but adding one of the CEST indices in GMV improved the classification between the subject groups. The largest improvement was seen in the MTR asym values at 2 ppm in the anterior cingulate (area under the ROC curve = 0.981), with a sensitivity of 100 and a specificity of 90.91. @*Conclusion@#CEST MRI potentially allows noninvasive image alterations in the Alzheimer’s disease brain without injecting isotopes for monitoring different disease states and may provide a new imaging biomarker in the future.

3.
Article in English | WPRIM | ID: wpr-740160

ABSTRACT

PURPOSE: One of the suggested potential mechanisms of tinnitus is an alteration in perception in the neural auditory pathway. The aim of this study was to investigate the difference in laterality in functional connectivity between tinnitus patients and healthy controls using resting state functional MRI (rs-fMRI). MATERIALS AND METHODS: Thirty-eight chronic tinnitus subjects and 45 age-matched healthy controls were enrolled in this study. Connectivity was investigated using independent component analysis, and the laterality index map was calculated based on auditory (AN) and dorsal attention (DAN), default mode (DMN), sensorimotor, salience (SalN), and visual networks (VNs). The laterality index (LI) of tinnitus subjects was compared with that of normal controls using region-of-interest (ROI) and voxel-based methods and a two-sample unpaired t-test. Pearson correlation was conducted to assess the associations between the LI in each network and clinical variables. RESULTS: The AN and VN showed significant differences in LI between the two groups in ROI analysis (P < 0.05), and the tinnitus group had clusters with significantly decreased laterality of AN, SalN, and VN in voxel-based comparisons. The AN was positively correlated with tinnitus distress (tinnitus handicap inventory), and the SalN was negatively correlated with symptom duration (P < 0.05). CONCLUSION: The results of this study suggest that various functional networks related to psychological distress can be modified by tinnitus, and that this interrelation can present differently on the right and left sides, according to the dominance of the network.


Subject(s)
Auditory Pathways , Humans , Magnetic Resonance Imaging , Tinnitus
4.
Article in English | WPRIM | ID: wpr-764184

ABSTRACT

PURPOSE: The purpose of this study was to investigate if double inversion recovery (DIR) imaging can have a role in the evaluation of brain ischemia, compared with diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) imaging. MATERIALS AND METHODS: Sixty-seven patients within 48 hours of onset, underwent MRI scans with FLAIR, DWI with b-value of 0 (B0) and 1000 s/mm², and DIR sequences. Patients were categorized into four groups: within three hours, three to six hours, six to 24 hours, and 24 to 48 hours after onset. Lesion-to-normal ratio (LNR) value was calculated and compared among all sequences within each group, by the Friedman test and conducted among all groups, for each sequence by the Kruskal-Wallis test. In qualitative assessment, signal intensity changes of DIR, B0, and FLAIR based on similarity with DWI and image quality of each sequence, were graded on a 3-point scale, respectively. Scores for detectability of lesions were compared by the McNemar's test. RESULTS: LNR values from DWI were higher than DIR, but not statistically significant in all groups (P > 0.05). LNR values of DIR were significantly higher than FLAIR within 24 hours of onset (P < 0.05). LNR values were significantly different between, before, and after six hours onset time for DIR (P = 0.016), B0 (P = 0.008), and FLAIR (P = 0.018) but not for DWI (P = 0.051). Qualitative analysis demonstrated that detectability of DIR was higher, compared to that of FLAIR within 4.5 hours and six hours of onset (P < 0.05). Also, the DWI quality score was lower than that of DIR, particularly relative to infratentorial lesions. CONCLUSION: DIR provides higher detectability of hyperacute brain ischemia than B0 and FLAIR, and does not suffer from susceptibility artifact, unlike DWI. So, DIR can be used to replace evaluation of the FLAIR-DWI mismatch.


Subject(s)
Artifacts , Brain Infarction , Brain Ischemia , Diffusion Magnetic Resonance Imaging , Humans , Magnetic Resonance Imaging , Stroke
5.
Psychiatry Investigation ; : 1174-1180, 2018.
Article in English | WPRIM | ID: wpr-719187

ABSTRACT

OBJECTIVE: Structural changes of brain areas have been reported in depressive disorder and suicidal behavior (SB), in which TPH1 also has been known as a promising candidate gene. We investigated gray matter volume (GMV) differences, TPH1 rs1800532 and rs1799913 polymorphisms previously found to be associated with depressive disorder and SB, and the relationship between the two markers. METHODS: Thirteen depressive disorder patients with suicidal attempts (SA) and twenty healthy controls were included. We examined GMV differences using a voxel-based morphometry and regions of interest analysis. Direct sequencing was used for genotyping. RESULTS: The patients showed significant GMV reduction in left cerebral region including middle frontal gyrus, inferior frontal gyrus, and anterior cingulate cortex; in right middle temporal gyrus; in left cerebellar tonsil; and in right cerebral region including precentral gyrus and postcentral gyrus (corrected p < 0.005). The right precentral and postcentral gyri GMV values of AA and CA genotypes patients were significantly decreased compared to those of CC genotype subjects (corrected p=0.040). CONCLUSION: These findings show the possibility that both GMV reductions and TPH1 rs1800532/rs1799913 A allele may be involved in the pathogenesis of depressive disorder patients with SA.


Subject(s)
Alleles , Brain , Depressive Disorder , Frontal Lobe , Genotype , Gray Matter , Gyrus Cinguli , Humans , Palatine Tonsil , Prefrontal Cortex , Somatosensory Cortex , Temporal Lobe
6.
Article in English | WPRIM | ID: wpr-716331

ABSTRACT

OBJECTIVE: To evaluate the inter-vendor and inter-session reliability of diffusion tensor imaging (DTI) and relevant parameters. MATERIALS AND METHODS: This prospective study included 10 healthy subjects (5 women and 5 men; age range, 25–33 years). Each subject was scanned twice using 3T magnetic resonance scanners from three different vendors at two different sites. A voxel-wise statistical analysis of diffusion data was performed using Tract-Based Spatial Statistics. Fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) values were calculated for each brain voxel using FMRIB's Diffusion Toolbox. RESULTS: A repeated measures analysis of variance revealed that there were no significant differences in FA values across the vendors or between sessions; however, there were significant differences in MD values between the vendors (p = 0.020). Although there were no significant differences in inter-session MD and inter-session/inter-vendor RD values, a significant group × factor interaction revealed differences in MD and RD values between the 1st and 2nd sessions conducted by the vendors (p = 0.004 and 0.006, respectively). CONCLUSION: Although FA values exhibited good inter-vendor and inter-session reliability, MD and RD values did not show consistent results. Researchers using DTI should be aware of these limitations, especially when implementing DTI in multicenter studies.


Subject(s)
Anisotropy , Brain , Commerce , Diffusion Tensor Imaging , Diffusion , Female , Healthy Volunteers , Humans , Male , Prospective Studies
7.
Article in English | WPRIM | ID: wpr-208822

ABSTRACT

OBJECTIVE: The purpose of this study was to estimate the T2* relaxation time in breast cancer, and to evaluate the association between the T2* value with clinical-imaging-pathological features of breast cancer. MATERIALS AND METHODS: Between January 2011 and July 2013, 107 consecutive women with 107 breast cancers underwent multi-echo T2*-weighted imaging on a 3T clinical magnetic resonance imaging system. The Student's t test and one-way analysis of variance were used to compare the T2* values of cancer for different groups, based on the clinical-imaging-pathological features. In addition, multiple linear regression analysis was performed to find independent predictive factors associated with the T2* values. RESULTS: Of the 107 breast cancers, 92 were invasive and 15 were ductal carcinoma in situ (DCIS). The mean T2* value of invasive cancers was significantly longer than that of DCIS (p = 0.029). Signal intensity on T2-weighted imaging (T2WI) and histologic grade of invasive breast cancers showed significant correlation with T2* relaxation time in univariate and multivariate analysis. Breast cancer groups with higher signal intensity on T2WI showed longer T2* relaxation time (p = 0.005). Cancer groups with higher histologic grade showed longer T2* relaxation time (p = 0.017). CONCLUSION: The T2* value is significantly longer in invasive cancer than in DCIS. In invasive cancers, T2* relaxation time is significantly longer in higher histologic grades and high signal intensity on T2WI. Based on these preliminary data, quantitative T2* mapping has the potential to be useful in the characterization of breast cancer.


Subject(s)
Breast Neoplasms , Breast , Carcinoma, Intraductal, Noninfiltrating , Female , Humans , Linear Models , Magnetic Resonance Imaging , Multivariate Analysis , Relaxation
8.
Article in English | WPRIM | ID: wpr-289677

ABSTRACT

<p><b>OBJECTIVES</b>To evaluate the effect of Uhwang Chungsim Won [UC, Niuhuang Qingxin Pill ()] on the blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signal response to a motor stimulation task using a hand grasping paradigm.</p><p><b>METHODS</b>Ten healthy right-handed male volunteers were recruited. Their BOLD fMRI signal characteristics during hand grasping were determined before and 1 h after consuming UC.</p><p><b>RESULTS</b>With the administration of UC, BOLD responses to the right hand motor task showed a decrease in both hemispheres including the right cerebellar culmen, right and left medial frontal gyrus, right parahippocampal gyrus, right and left sublobar insula, right and left posterior cingulate, left precuneus, and right precentral gyrus. Decreased BOLD responses to the left hand motor task were shown in the right lingual gyrus, right cerebellar culmen, left superior temporal gyrus, right and left middle frontal gyrus, and right precentral gyrus after UC administration. Increased BOLD responses to the left hand motor task were shown in the left and right posterior cingulate, while there was no increased response to the right hand motor task after UC administration.</p><p><b>CONCLUSIONS</b>UC administration significantly decreased fMRI BOLD signal responses to hand grasping in most of the brain areas including the primary motor cortex, but it is not clear whether these decreased responses were caused by a decrease in neuronal activities or by an increase in cerebral blood flow due to the cerebral vasodilatory effects of UC. Further studies using positron emission tomography or single photon emission computed tomography are needed to fully elucidate these findings.</p>


Subject(s)
Adult , Brain Mapping , Drugs, Chinese Herbal , Pharmacology , Hand , Physiology , Hand Strength , Physiology , Humans , Magnetic Resonance Imaging , Male , Motor Activity , Physiology , Oxygen , Blood , Signal Processing, Computer-Assisted , Task Performance and Analysis
9.
Article in English | WPRIM | ID: wpr-183063

ABSTRACT

OBJECTIVE: To validate the usefulness of a diffusional anisotropic capillary array phantom and to investigate the effects of diffusion tensor imaging (DTI) parameter changes on diffusion fractional anisotropy (FA) and apparent diffusion coefficient (ADC) using the phantom. MATERIALS AND METHODS: Diffusion tensor imaging of a capillary array phantom was performed with imaging parameter changes, including voxel size, number of sensitivity encoding (SENSE) factor, echo time (TE), number of signal acquisitions, b-value, and number of diffusion gradient directions (NDGD), one-at-a-time in a stepwise-incremental fashion. We repeated the entire series of DTI scans thrice. The coefficients of variation (CoV) were evaluated for FA and ADC, and the correlation between each MR imaging parameter and the corresponding FA and ADC was evaluated using Spearman's correlation analysis. RESULTS: The capillary array phantom CoVs of FA and ADC were 7.1% and 2.4%, respectively. There were significant correlations between FA and SENSE factor, TE, b-value, and NDGD, as well as significant correlations between ADC and SENSE factor, TE, and b-value. CONCLUSION: A capillary array phantom enables repeated measurements of FA and ADC. Both FA and ADC can vary when certain parameters are changed during diffusion experiments. We suggest that the capillary array phantom can be used for quality control in longitudinal or multicenter clinical studies.


Subject(s)
Anisotropy , Diffusion Magnetic Resonance Imaging/instrumentation , Diffusion Tensor Imaging/instrumentation , Humans , Phantoms, Imaging , Research Design , Signal-To-Noise Ratio
10.
Neurointervention ; : 9-20, 2014.
Article in English | WPRIM | ID: wpr-730178

ABSTRACT

Intracranial atherosclerotic disease (ICAD) causes up to 10% of all ischemic strokes, and the rate of recurrent vascular ischemic events is very high. Important predictors of vulnerability in atherosclerotic plaques include the degree of stenosis and the underlying plaque morphology. Vascular wall MRI can provide information about wall structures and atherosclerotic plaque components. High-resolution (HR)-MRI in ICAD poses a greater challenge in the neurologic fields, because a high in-plane resolution and a high signal-to-noise ratio are required for vessel wall imaging of ICAD. Until now, plaque imaging of ICAD has focused on assessing the presence of a plaque and evaluating the plaque load. Going forward, evaluation of plaque vulnerability through analysis of imaging characteristics will be a critical area of research. This review introduces the acquisition protocol for HR-MRI in ICAD and the current issues associated with imaging.


Subject(s)
Atherosclerosis , Cerebral Arteries , Constriction, Pathologic , Magnetic Resonance Imaging , Plaque, Atherosclerotic , Signal-To-Noise Ratio , Stroke
11.
Article in English | WPRIM | ID: wpr-95308

ABSTRACT

Perfusion is a fundamental biological function that refers to the delivery of oxygen and nutrients to tissue by means of blood flow. Perfusion MRI is sensitive to microvasculature and has been applied in a wide variety of clinical applications, including the classification of tumors, identification of stroke regions, and characterization of other diseases. Perfusion MRI techniques are classified with or without using an exogenous contrast agent. Bolus methods, with injections of a contrast agent, provide better sensitivity with higher spatial resolution, and are therefore more widely used in clinical applications. However, arterial spin-labeling methods provide a unique opportunity to measure cerebral blood flow without requiring an exogenous contrast agent and have better accuracy for quantification. Importantly, MRI-based perfusion measurements are minimally invasive overall, and do not use any radiation and radioisotopes. In this review, we describe the principles and techniques of perfusion MRI. This review summarizes comprehensive updated knowledge on the physical principles and techniques of perfusion MRI.


Subject(s)
Arteries/chemistry , Brain Neoplasms/diagnostic imaging , Contrast Media , Humans , Magnetic Resonance Imaging/standards , Spin Labels , Stroke/diagnostic imaging
12.
Article in English | WPRIM | ID: wpr-223489

ABSTRACT

PURPOSE: T2* relaxation time which includes susceptibility information represents unique feature of tissue. The objective of this study was to investigate T2* relaxation times of the normal glandular tissue and fat of breast using a 3T MRI system. MATERIALS AND METHODS: Seven-echo MR Images were acquired from 52 female subjects (age 49 +/- 12 years; range, 25 to 75) using a three-dimensional (3D) gradient-echo sequence. Echo times were between 2.28 ms to 25.72 ms in 3.91 ms steps. Voxel-based T2* relaxation times and R2* relaxation rate maps were calculated by using the linear curve fitting for each subject. The 3D regions-of-interest (ROI) of the normal glandular tissue and fat were drawn on the longest echo-time image to obtain T2* and R2* values. Mean values of those parameters were calculated over all subjects. RESULTS: The 3D ROI sizes were 4818 +/- 4679 voxels and 1455 +/- 785 voxels for the normal glandular tissue and fat, respectively. The mean T2* values were 22.40 +/- 5.61 ms and 36.36 +/- 8.77 ms for normal glandular tissue and fat, respectively. The mean R2* values were 0.0524 +/- 0.0134/ms and 0.0297 +/- 0.0069/ms for the normal glandular tissue and fat, respectively. CONCLUSION: T2* and R2* values were measured from human breast tissues. T2* of the normal glandular tissue was shorter than that of fat. Measurement of T2* relaxation time could be important to understand susceptibility effects in the breast cancer and the normal tissue.


Subject(s)
Breast Neoplasms , Breast , Female , Humans , Magnetic Resonance Imaging , Relaxation
13.
Article in Korean | WPRIM | ID: wpr-223485

ABSTRACT

PURPOSE: To evaluate the correlation of lesion-to-normal ratio (LNR) of signal intensity from double inversion recovery MR imaging and total choline-containing compound (tCho) resonance from single voxel MR spectroscopy in breast cancers. MATERIALS AND METHODS: Between August 2008 and December 2009, 28 patients who were diagnosed as breast cancer and had undergone both double inversion recovery (DIR) MR imaging and MR spectroscopy (MRS) were included in this study. The signal intensities of the lesion (L) and ipsilateral normal breast tissue (N) were measured in region of interest of each breast cancer in DIR and contrast enhance MR image (CE-T1WI) to calculate the LNR value for each technique. MRS was performed using single-voxel MR spectroscopy. The height, width and area of tCho resonance were compared with each LNR of DIR and CE-T1WI. We used Pearson's correlation coefficient (r) for correlation analysis and the significance level was p=0.05. RESULTS: There was no statistically significant correlation between LNR of CE-T1WI and height (r=-0.322, p=0.094), width (r=-0.233, p=0.232) and area (r=-0.309, p=0.109) of MRS tCho. There was no statistically significant correlation between LNR of DIR and height (r=0.067, p=0.735), width (r=-0.287, p=0.139) and area (r=0.012, p=0.953) of MRS tCho, either. The Pearson's correlation coefficient was 0.186 between LNRs of CE-T1WI and DIR (p=0.344). CONCLUSION: There was no statistically significant correlation between LNR of DIR and relative amount of tCho resonance of MRS.


Subject(s)
Breast Neoplasms , Breast , Humans , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy
14.
Article in English | WPRIM | ID: wpr-140391

ABSTRACT

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.


Subject(s)
Adult , Astrocytoma , Blood Volume , Brain , Brain Neoplasms , Corpus Callosum , Diagnosis , Edema , Female , Frontal Lobe , Glioma , Humans , Magnetic Resonance Angiography , Magnetic Resonance Imaging , Perfusion , Permeability , World Health Organization
15.
Article in English | WPRIM | ID: wpr-140390

ABSTRACT

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.


Subject(s)
Adult , Astrocytoma , Blood Volume , Brain , Brain Neoplasms , Corpus Callosum , Diagnosis , Edema , Female , Frontal Lobe , Glioma , Humans , Magnetic Resonance Angiography , Magnetic Resonance Imaging , Perfusion , Permeability , World Health Organization
16.
Article in English | WPRIM | ID: wpr-23919

ABSTRACT

PURPOSE: To evaluate the relationship between the speed of enhancement of hepatic hemangiomas on gadolinium-enhanced MRI and ADC values by using various parameters, including the D, f, D* and ADC(fit) on intravoxel incoherent motion (IVIM) MR Imaging. MATERIALS AND METHODS: The institutional review board approved this retrospective study. A total of 47 hepatic hemangiomas from 39 patients were included (20 men and 19 women). The hemangiomas were classified into three types according to the enhancement speed of the hepatic hemangiomas on gadolinium-enhanced dynamic T1-weighted images: rapid (Type A), intermediate (Type B), and slow (Type C) enhancement. The D, f, D* and ADC(fit) values were calculated using IVIM MR imaging. The diffusion/perfusion parameters and ADC values were compared among the three types of hemangiomas. RESULTS: Both the ADC(fit) and D values of type C were significantly lower than those of type A (P = 0.0022, P = 0.0085). However, for the f and D*, there were no significant differences among the three types. On DWI with all b values (50, 200, 500 and 800 sec/mm2), the ADC values of type C were significantly lower than those of the type A (P < 0.012). For b values with 800 sec/mm2, the ADC800 values of the type C hemangiomas were significantly lower than those of type B (P = 0.0021). We found a negative correlation between hepatic hemangioma enhancement type and ADC50 (rho= -0.357, P = 0.014), ADC200 (rho= -0.537, P = 0.0001), ADC500 (rho= -0.614, P = 0.0001), and ADC800(rho= -0.607, P = 0.0001). Therefore, four ADC values of ADC50, ADC200, ADC500, and ADC800 were decreased with decreasing enhancement speed. CONCLUSION: Hepatic hemangiomas had variable ADCs according to the type of enhancement, and the reduced ADCs in slowly enhancing hemangiomas may be related to the reduced pure molecular diffusion (D).


Subject(s)
Diffusion , Ethics Committees, Research , Hemangioma , Humans , Magnetic Resonance Imaging , Male , Retrospective Studies
17.
Article in English | WPRIM | ID: wpr-293318

ABSTRACT

<p><b>OBJECTIVE</b>To determine whether jaw-tapping movement, a classically described as an indication of personal well-being and mental health, stimulates the memory and the cognitive regions of the brain and is associated with improved brain performance.</p><p><b>METHODS</b>Twelve healthy right-handed female subjects completed the study. Each patient performed a jaw-tapping task and an n-back task during functional magnetic resonance imaging (fMRI). The subjects were trained to carry out the jaw-tapping movement at home twice a day for 4 weeks. The fMRI was repeated when they returned.</p><p><b>RESULTS</b>During the first and second jaw-tapping session, both sides of precentral gyrus and the right middle frontal gyrus (BA 6) were activated. And during the second session of the jaw-tapping task, parts of frontal lobe and temporal lobe related to memory function were more activated. In addition, the total percent task accuracy in n-back task significantly increased after 4 weeks of jawtapping movement. After jaw-tapping training for 4 weeks, brain areas related to memory showed significantly increased blood oxygen level dependent signals.</p><p><b>CONCLUSION</b>Jaw-tapping movement might be a useful exercise for stimulating the memory and cognitive regions of the brain.</p>


Subject(s)
Brain , Physiology , Brain Mapping , Cognition , Physiology , Female , Health , Humans , Jaw , Physiology , Magnetic Resonance Imaging , Memory , Physiology , Middle Aged , Movement , Physiology , Task Performance and Analysis
18.
Article in English | WPRIM | ID: wpr-293278

ABSTRACT

<p><b>OBJECTIVE</b>To investigate brain activity patterns during acupuncture in stroke patients, and to compare the result with normal subjects using functional magnetic resonance imaging (fMRI).</p><p><b>METHODS</b>A total of 11 stroke patients with motor weakness and 10 healthy subjects were studied. fMRI was performed during acupuncture on the left side at points Quchi (LI11) and Zusanli (ST36). Data were analyzed using statistical parametric maps of brain activation induced by acupuncture stimulation.</p><p><b>RESULTS</b>The results showed that stimulation of both LI11 and ST36 produced significantly different brain activation patterns between the two groups. The normal group showed a greater overall activation than the stroke group. In the normal group, parts of the frontal lobe, parietal lobe, sub-lobar, cerebellum and midbrain regions were activated by acupuncture at the left LI11. On the other hand, only the right side of the inferior parietal lobule region was activated in the stroke patients. When the left ST36 was stimulated in the normal group, both sides of the frontal lobe, parietal lobe, temporal lobe, and sub-lobar, and the left side of occipital lobe, and the right side of cerebellum and midbrain regions were activated. For the same stimulation in the stroke group, only both sides of the inferior parietal lobule and cerebellum regions were activated (P<0.05, cluster level). Deactivation pattern was not noted during any acupuncture stimulation in both groups.</p><p><b>CONCLUSION</b>Brain signal activations during the same acupuncture were different between the healthy and the stroke patients, and the effects showed a correlation of different acupuncture points.</p>


Subject(s)
Acupuncture Therapy , Aged , Brain Mapping , Case-Control Studies , Demography , Female , Health , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Stroke
19.
Article in English | WPRIM | ID: wpr-72361

ABSTRACT

OBJECTIVE: The purpose of this study was to differentiate true progression from pseudoprogression of glioblastomas treated with concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ) by using histogram analysis of apparent diffusion coefficient (ADC) and normalized cerebral blood volume (nCBV) maps. MATERIALS AND METHODS: Twenty patients with histopathologically proven glioblastoma who had received CCRT with TMZ underwent perfusion-weighted imaging and diffusion-weighted imaging (b = 0, 1000 sec/mm2). The corresponding nCBV and ADC maps for the newly visible, entirely enhancing lesions were calculated after the completion of CCRT with TMZ. Two observers independently measured the histogram parameters of the nCBV and ADC maps. The histogram parameters between the true progression group (n = 10) and the pseudoprogression group (n = 10) were compared by use of an unpaired Student's t test and subsequent multivariable stepwise logistic regression analysis to determine the best predictors for the differential diagnosis between the two groups. Receiver operating characteristic analysis was employed to determine the best cutoff values for the histogram parameters that proved to be significant predictors for differentiating true progression from pseudoprogression. Intraclass correlation coefficient was used to determine the level of inter-observer reliability for the histogram parameters. RESULTS: The 5th percentile value (C5) of the cumulative ADC histograms was a significant predictor for the differential diagnosis between true progression and pseudoprogression (p = 0.044 for observer 1; p = 0.011 for observer 2). Optimal cutoff values of 892 x 10-6 mm2/sec for observer 1 and 907 x 10-6 mm2/sec for observer 2 could help differentiate between the two groups with a sensitivity of 90% and 80%, respectively, a specificity of 90% and 80%, respectively, and an area under the curve of 0.880 and 0.840, respectively. There was no other significant differentiating parameter on the nCBV histograms. Inter-observer reliability was excellent or good for all histogram parameters (intraclass correlation coefficient range: 0.70-0.99). CONCLUSION: The C5 of the cumulative ADC histogram can be a promising parameter for the differentiation of true progression from pseudoprogression of newly visible, entirely enhancing lesions after CCRT with TMZ for glioblastomas.


Subject(s)
Adult , Aged , Brain Neoplasms/pathology , Cerebrovascular Circulation/physiology , Combined Modality Therapy , Diagnosis, Differential , Diffusion Magnetic Resonance Imaging/methods , Disease Progression , Female , Glioblastoma/pathology , Humans , Male , Middle Aged , Prognosis , ROC Curve , Regional Blood Flow , Reproducibility of Results , Retrospective Studies
20.
Article in English | WPRIM | ID: wpr-118492

ABSTRACT

OBJECTIVE: There is a rich literature confirming the default mode network found compatible with task-induced deactivation regions in normal subjects, but few investigations of alterations of the motor deactivation in patients with intracranial lesions. Therefore, we hypothesized that an intracranial lesion results in abnormal changes in a task-induced deactivation region compared with default mode network, and these changes are associated with specific attributes of allocated regions. METHODS: Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) during a motor task were obtained from 27 intracranial lesion patients (mean age, 57.3 years; range 15-78 years) who had various kinds of brain tumors. The BOLD fMRI data for each patient were evaluated to obtain activation or deactivation regions. The distinctive deactivation regions from intracranial lesion patients were evaluated by comparing to the literature reports. RESULTS: There were additive deactivated regions according to intracranial lesions: fusiform gyrus in cavernous hemangioma; lateral occipital gyrus in meningioma; crus cerebri in hemangiopericytoma; globus pallidus, lateral occipital gyrus, caudate nucleus, fusiform gyrus, lingual gyrus, claustrum, substantia nigra, subthalamic nucleus in GBM; fusiform gyrus in metastatic brain tumors. CONCLUSION: There is increasing interest in human brain function using fMRI. The authors report the brain function migrations and changes that occur in patients with intracranial lesions.


Subject(s)
Basal Ganglia , Brain , Brain Neoplasms , Caudate Nucleus , Globus Pallidus , Hemangioma, Cavernous , Hemangiopericytoma , Humans , Magnetic Resonance Imaging , Meningioma , Oxygen , Substantia Nigra , Subthalamic Nucleus
SELECTION OF CITATIONS
SEARCH DETAIL