• Title/Summary/Keyword: Brain mapping

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Cerebrocortical Regions Associated with Implicit and Explicit Memory Retrieval Under the Conceptual Processing: BOLD Functional MR Imaging

  • Kim, Hyung-Joong;Kang, Hyung-Geun;Seo, Jung-Jin;Jung, Kwang-Woo;Eun, Sung-Jong;Park, Jin-Kyun;Yoon, Woong;Park, Tae-Jin
    • Proceedings of the KSMRM Conference
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    • 2002.11a
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    • pp.111-111
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    • 2002
  • Purpose: This study is to compare the distinct brain activation between implicit and explicit memory retrieval tasks using a non-invasive blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging(fMRI). Materials & Methods: We studied seven right-handed, healthy volunteers aged 21-25 years(mean;22 years) were scanned under a 1.5T Signa Horizon Echospeed MR imager(GE Medical Systems, Milwaukee, U.S.A.). During the implicit and explicit memory retrieval tasks of previously teamed words under the conceptual processing, we acquired fMRI data using gradient-echo EPI with 50ms TE, 3000ms TR, 26cm${\times}$26cm field-of-view, 128${\times}$128 matrix, and ten slices(6mm slice thickness, 1 mm gap) parallel to the AC-PC(anterior commissure and posterior commissure) line. By using the program of statistical parametric mapping(SPM99), functional activation maps were reconstructed and quantified.

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New Model of Verifiation for Demonstration of Neuronal Basis of Acupuncture by Comparison of Two Different Methods of Acupuncture which Increase Regional Cerebral Blood Flow ( rCBF ) on SPECT (핵의학(SPECT)을 이용한 뇌혈류변화에 대한 침구효과 검증방법의 새로운 모델에 관한 연구)

  • Ahn, Soog-Gi;Kang, Hwa-Jeong;Song, Ho-Chun;Bom, Hee-Seung
    • Journal of Acupuncture Research
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    • v.17 no.2
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    • pp.247-259
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    • 2000
  • Objective : The mechanism of acupuncture to increase cerebral blood flow is still uncertain. The purpose of this study was to evaluate the neural basis of acupuncture by comparing the cerebral regions activated by the stimulation of two different methods of acupunctures at the same acupoint which was suggested by oriental medicine to increase rCBF. Materials and Methods : Thirty-nine healthy volunteers(26 males, 13 females, age $31{\pm}11$ years) were studies by rest/acupuncture Tc-99m ECD brain SPECT using a subtraction method. SPECTs using two methods(needle retention and heated needle with 90% alcohol) at two acupoints (right LI. 4 and ST. 36) were peformed at an interval of three days. For the needle retention method, acupuncture needle was inserted to a depth of about 2 cm into each acupoint 8 minutes after the lst acquisition and continued to retain, and the second injection of Tc-99m ECD was done 15 minutes after the insertion of needle. For the heated acupuncture method, heated needle was inserted in a twinkle within several msec 20 second after the second injection of Tc-99m ECD. The differences of between rest and acupuncture activation state were statistically analyzed using a statistical parametric mapping software. Result : Acupunctures of both methods reveal similar patterns of increase in rCBF. Acupuncture at ST.36 increase rGBF in left anterior temporal, right inferior frontal lobes, and left cerebellum. Acupuncture at LI. 4 increase rCBF in the left frontal cortex, right temporal pole, both inferior frontal cortices and right cerebellum. Conclusion : The effects of two different acupunctures to the same acupoints on rCBF were similar. Therefore, this result suggests Chat the mechanism of acupuncture in the increase of cerebral blood flow have a neural basis.

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Technical Considerations of Effective Direct Cortical and Subcortical Stimulation (효과적인 대뇌 직접피질자극 검사 및 피질하자극 검사의 술기에 관한 기술적 고찰)

  • Lim, Sung Hyuk;Jang, Min Hwan
    • Korean Journal of Clinical Laboratory Science
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    • v.54 no.2
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    • pp.157-162
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    • 2022
  • The purpose of the direct cortical and subcortical stimulation technique is to prevent false positives caused by transcranial electrical motor evoked potentials (TceMEP) in surgery on patients with brain tumors that have occurred around the motor cortex and to preserve the correct mapping of motor areas during surgery and the corticospinal tract. In addition, it reduces the trial and error that occurs during the intraoperative neurophysiological monitoring (INM) process and minimizes the test time, so that accurate information is communicated to the surgeon with quick feedback on the test results. The most important factors of this technique are, first, examination at a stimulus threshold of a certain intensity, and second, maintaining anesthesia depth at an appropriate level to prevent false positives from occurring during surgery. The third is the installation of a multi-level channel recording electrode on the opposite side of the area of operation to measure the TceMEP waveform and the response to direct cortical and subcortical stimulation in as many muscles as possible. If these conditions are maintained, it is possible to predict causes that may occur in other factors, not false positives, from the INM test.

Application of T1 Map Information Based on Synthetic MRI for Dynamic Contrast-Enhanced Imaging: A Comparison Study with the Fixed Baseline T1 Value Method

  • Dong Jae Shin;Seung Hong Choi;Roh-Eul Yoo;Koung Mi Kang;Tae Jin Yun;Ji-Hoon Kim;Chul-Ho Sohn;Sang Won Jo;Eun Jung Lee
    • Korean Journal of Radiology
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    • v.22 no.8
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    • pp.1352-1368
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    • 2021
  • Objective: For an accurate dynamic contrast-enhanced (DCE) MRI analysis, exact baseline T1 mapping is critical. The purpose of this study was to compare the pharmacokinetic parameters of DCE MRI using synthetic MRI with those using fixed baseline T1 values. Materials and Methods: This retrospective study included 102 patients who underwent both DCE and synthetic brain MRI. Two methods were set for the baseline T1: one using the fixed value and the other using the T1 map from synthetic MRI. The volume transfer constant (Ktrans), volume of the vascular plasma space (vp), and the volume of the extravascular extracellular space (ve) were compared between the two methods. The interclass correlation coefficients and the Bland-Altman method were used to assess the reliability. Results: In normal-appearing frontal white matter (WM), the mean values of Ktrans, ve, and vp were significantly higher in the fixed value method than in the T1 map method. In the normal-appearing occipital WM, the mean values of ve and vp were significantly higher in the fixed value method. In the putamen and head of the caudate nucleus, the mean values of Ktrans, ve, and vp were significantly lower in the fixed value method. In addition, the T1 map method showed comparable interobserver agreements with the fixed baseline T1 value method. Conclusion: The T1 map method using synthetic MRI may be useful for reflecting individual differences and reliable measurements in clinical applications of DCE MRI.

Brain F-18 FDG PET for localization of epileptogenic zones in frontal lobe epilepsy: visual assessment and statistical parametric mapping analysis (전두엽 간질에서 F-18-FDG PET의 간질병소 국소화 성능: 육안 판독과 SPM에 의한 분석)

  • Kim, Yu-Kyeong;Lee, Dong-Soo;Lee, Sang-Kun;Chung, Chun-Kee;Yeo, Jeong-Seok;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.3
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    • pp.131-141
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    • 2001
  • Purpose: We evaluated the sensitivity of the F-18 FDG PET by visual assessment and statistical parametric mapping (SPM) analysis for the localization of the epileptogenic zones in frontal lobe epilepsy. Materials and Methods: Twenty-four patients with frontal lobe epilepsy were examined. All patients exhibited improvements after surgical resection (Engel class I or II). Upon pathological examination, 18 patients revealed cortical dysplasia, 4 patients revealed tumor, and 2 patients revealed cortical scar. The hypometabolic lesions were found in F-18 FDG PET by visual assessment and SPM analysis. On SPM analysis, cutoff threshold was changed. Results: MRI showed structural lesions in 12 patients and normal results in the remaining 12. F-18 FDG PET correctly localized epileptogenic zones in 13 patients (54%) by visual assessment. Sensitivity of F-18 FDG PET in MR-negative patients (50%) was similar to that in MR-positive patients (67%). On SPM analysis, sensitivity decreased according to the decrease of p value. Using uncorrected p value of 0.05 as threshold, sensitivity of SPM analysis was 53%, which was not statistically different from that of visual assessment. Conclusion: F-18 FDG PET was sensitive in finding epileptogenic zones by revealing hypometabolic areas even in MR-negative patients with frontal lobe epilepsy as well as in MR-positive patients. SPM analysis showed comparable sensitivity to visual assessment and could be used as an aid in the diagnosis of epileptogenic zones in frontal lobe epilepsy.

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Functional MRI ofThe Supplementary Motor Area in Hand Motor Task: Comparison Study with The Primary Motor Area (수지운동자극을 사용한 부운동중추의 기능적 MR연구: 일차운동중추와의 비교)

  • 이호규;김진서;최충곤;임태환
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.103-107
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    • 1997
  • Purpose: To investigate the localization and functional lateralization of the supplementary motor area (SMA) in motor activation tests in comparison to that of the primary motor area. Materials and Methods: Seven healthy volunteers obtained echoplanar imaging blood oxygen level dependent technique. This study was carried on 1.5T Siemens Magnetom Vision system with the standard head coil. Parameters of EPI were followed as; TR/TE : 1.0/66.0msec, flip angle: $90^{\circ}$, field of view: $22cm{\times}22cm,{\;}matrix:{\;}128{\times}128$, slice number/slice thickness/gap: 1O/4mm/0.8mm with fat suppression technique. Motor task as finger opposition in each hand consisted of 3 sets of alternative rest and activation periods. Postprocessing were done on Stimulate 5.0 by using cross-correlation statistics. To compare the functional lateralization of the SMA in the right and left hand tests, each examination was evaluated for the percent change of signal intensity and the number of activated voxels both in the SMA and in the pri¬mary motor area. Hemispheric asymmetry was defined as difference of summation of the activted voxels between each hemisphere. Results: Percent change of signal intensity in the SMA (2.49 -3.06%) is lower than that of primary motor area(4.4 -7.23%). Percent change of signal intensity including activated voxels were observed almost equally in the right and left SMA. As for summation of activated voxels, primary motor area had significant difference between each hemisphere but not did the SMA. Conclusion: Preferred contralateral dominant hemisphere and hemispheric asymmetry were detected in the primary motor area but not in the SMA.

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Current Status and Future Perspective of PET (PET 이용 현황 및 전망)

  • Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.36 no.1
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    • pp.1-7
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    • 2002
  • Positron Emission Tomography (PET) is a nuclear medicine imaging modality that consists of systemic administration to a subject of a radiopharmaceutical labeled with a positron-emitting radionuclide. Following administration, its distribution in the organ or structure under study can be assessed as a function of time and space by (1) defecting the annihilation radiation resulting from the interaction of the positrons with matter, and (2) reconstructing the distribution of the radioactivity from a series of that used in computed tomography (CT). The nuclides most generally exhibit chemical properties that render them particularly desirable in physiological studies. The radionuclides most widely used in PET are F-18, C-11, O-15 and N-13. Regarding to the number of the current PET Centers worldwide (based on ICP data), more than 300 PET Centers were in operation in 2000. The use of PET technology grew rapidly compared to that in 1992 and 1996, particularly in the USA, which demonstrates a three-fold rise in PET installations. In 2001, 194 PET Centers were operating in the USA. In 1994, two clinical and research-oriented PET Centers at Seoul National University Hospital and Samsung Medical Center, was established as the first dedicated PET and Cyclotron machines in Korea, followed by two more PET facilities at the Korea Cancer Center Hospital, Ajou Medical Center, Yonsei University Medical Center, National Cancer Center and established their PET Center. Catholic Medical School and Pusan National University Hospital have finalized a plan to install PET machine in 2002, which results in total of nine PET Centers in Korea. Considering annual trends of PET application in four major PET centers in Korea in Asan Medical Center recent six years (from 1995 to 2000), a total of 11,564 patients have been studied every year and the number of PET studies has shown steep growth year upon year. We had 1,020 PET patients in 1995. This number increased to 1,196, 1,756, 2,379, 3,015 and 4,414 in 1996,1997,1998,1999 and 2000, respectively. The application in cardiac disorders is minimal, and among various neuropsychiatric diseases, patients with epilepsy or dementia can benefit from PET studios. Recently, we investigated brain mapping and neuroreceptor works. PET is not a key application for evaluation of the cardiac patients in Korea because of the relatively low incidence of cardiac disease and less costly procedures such as SPECT can now be performed. The changes in the application of PET studios indicate that, initially, brain PET occupied almost 60% in 1995, followed by a gradual decrease in brain application. However, overall PET use in the diagnosis and management of patients with cancer was up to 63% in 2000. The current medicare coverage policy in the USA is very important because reimbursement policy is critical for the promotion of PET. In May 1995, the Health Care Financing Administration (HCFA) began covering the PET perfusion study using Rubidium-82, evaluation of a solitary pulmonary nodule and pathologically proven non-small cell lung cancer. As of July 1999, Medicare's coverage policy expanded to include additional indications: evaluation of recurrent colorectal cancer with a rising CEA level, staging of lymphoma and detection of recurrent or metastatic melanoma. In December of 2001, National Coverage decided to expand Medicare reimbursement for broad use in 6 cancers: lung, colorecctal, lymphoma, melanoma, head and neck, and esophageal cancers; for determining revascularization in heart diseases; and for identifying epilepsy patients. In addition, PET coverage is expected to further expand to diseases affecting women, such as breast, ovarian, uterine and vaginal cancers as well as diseases like prostate cancer and Alzheimer's disease.

Multi-Component Relaxation Study of Human Brain Using Relaxographic Analysis (Relaxographic 분석법을 이용한 뇌의 다중 자기이완특성에 관한 연구)

  • Yongmin Chang;Bong Soo Han;Bong Seok Kang;Kyungnyeo Jeon;Kyungsoo Bae;Yong-Sun Kim;Duk-Sik Kang
    • Investigative Magnetic Resonance Imaging
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    • v.6 no.2
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    • pp.120-128
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    • 2002
  • Purpose : To demonstrate that the relaxographic method provides additional information such as the distribution of relaxation times and water content which are poentially applicable to clinical medicine. Materials and Methods : First, the computer simulation was performed with the generated relaxation data to verify the accuracy and reliabilility of the relaxographic method (CONTINI). Secondly, in or der to see how well the CONTIN quantifies and resolves the two different ${T_1}$ environments, we calculated the oil to water peak area ratios and identified peak positions of ${T_1}-distribution$ curve of the phantom solutions, which consist of four centrifugal tubes (10 ml) filled with the compounds of 0, 10, 20, 30% of corn oil and distilled water, using CONTIN. Finally, inversion recovery MR images for a volunteer are acquired for each TI ranged from 40 to 1160 msec with TR/TE=2200/20 msec. From the 3 different ROIs (GM, WM, CSF), CONTIN analysis was performed to obtain the ${T_1}$-distribution curves, which gave peak positions and peak area of each ROI location. Results : The simulation result shows that the errors of peak positions were less in the higher peak (centered ${T_1}=600$ msec) than in the lower peak (centered ${T_1}=150$ msec) for all SNR but the errors of peak areas were larger in the higher peak than in the lower peak. The CONTIN analysis of the measured relaxation data of phantoms revealed two peaks between 20 and 60 msec and between 500 and 700 msec. The analysis gives the peak area ratio as oil 10%: oil 20%: oil 30% = 1:1.3:1.9, which is different from the exact ratio, 1:2:3. For human brain, in ROI 3 (CSF), only one component of -distributions was observed whereas in ROI 1(GM) and in ROI 2 (WM) we observed two components of ${T_1}-distribution$. For the WM and CSF there was great agreement between the observed ${T_1}-relaxation$ times and the reported values. Conclusion : we demonstrated that the relaxographic method provided additional information such as the distribution of relaxation times and water content, which were not available in the routine relaxometry and ${T_1}/{T_2}$ mapping techniques. In addition, these additional information provided by relaxographic analysis may have clinical importance.

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Effect of ST 36-ST 41 Electro-acupuncture on Regional Cerebral Blood Flow in Normal Volunteers Evaluated by $^{99m}Tc$-ECD SPECT (족삼리-해계 전침치료가 정상인의 국소 뇌혈류에 미치는 영향 -Brain SPECT와 SPM을 이용하여-)

  • Moon, Sang-Kwan;Min, In-Kyu;Park, Sung-Uk;Jung, Woo-Sang;Park, Jung-Mee;Ko, Chang-Nam;Cho, Ki-Ho;Bae, Hyung-Sup;Kim, Young-Suk;Kim, Deok-Yoon
    • The Journal of Korean Medicine
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    • v.31 no.1
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    • pp.130-137
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    • 2010
  • Objectives: So far it has been reported that acupuncture increases cerebral blood supply and stimulates the functional activity of brain nerve cells. Previous studies have demonstrated that frequently used electro-acupuncture (EA) therapies for stroke increased regional cerebral blood flow (rCBF) in normal volunteers. Though ST 36-ST 41 EA is another prevailing therapy for stroke, there had been no report about its effect on rCBF. This study was to evaluate the effect of ST 36-ST 41 EA on rCBF in normal volunteers using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Methods: In the resting state, $^{99m}Tc$-ECD brain SPECT scans were performed on 10 normal volunteers (5 males, 5 female, mean age $23.6{\pm}0.5$ years). On the other study day, 7 days after the resting examination, 15 minutesEA were applied at ST 36 and ST 41 on the right side of the subjects. Immediately after ST36-ST41 EA, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of rCBF after EA were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by SPM with a threshold of p = 0.01, uncorrected (extent threshold: k=100 voxels). Results: EA applied at the right ST36-ST41 significantly increased rCBF in the right inferior parietal lobule (Brodmann area [BA] 40), right retrosubicular area (BA 48), left inferior parietal lobule (BA 40), left middle temporal gyrus (BA 21), left fusiform gyrus (BA 37), left inferior parietal lobule (BA 39), left inferior temporal gyrus (BA 20), and left somatosensory association cortex (BA 7). However, right ST36-ST41 EA significantly decreased rCBF in the right parahippocampal gyrus (BA 35), right cerebellum, left frontopolar area (BA 10), left orbitofrontal area (BA 11), left dorsolateral prefrontal cortex (BA 9), and left dorsal anterior cingulate cortex (BA 32). Conclusions: These results demonstrate that rightST36-ST41 EA increased rCBF prominently in both inferior parietal lobule (BA 40) and right retrosubicular area (BA 48), which suggest that there be correlation between specific EA and corresponding rCBF.

Effect of Acupuncture on Regional Cerebral Blood Flow at Acupoints GV 20, GV. 26, LI. 4, ST. 36, SP. 6 Evaluated by Tc-99m ECD Brain SPECT (Tc-99m ECD 뇌혈류 SPECT를 이용한 백회, 인중, 합곡, 족삼리, 삼음교에서 체침의 뇌혈류에 대한 효과)

  • Song, Ho-Chun;Bom, Hee-Seung;Kang, Hwa-Jeong;Ahn, Soo-Gi;Kim, Seong-Min;Jeong, Hwan-Jeong;Kim, Ji-Yeul
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.6
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    • pp.456-464
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    • 2000
  • Purpose: To evaluate the effect of acupuncture on regional cerebral blood flow (rCBF) at acupoints suggested by oriental medicine to be related to the treatment of cerebrovascular diseases. Materials and Methods: Rest/acupuncture-stimulation Tc-99m ECD brain SPECT using a same-dose subtraction method was performed on 54 normal volunteers (34 males, 20 females, age range from 18 to 62 years) using six paradigms: acupuncture at acupoints GV. 20, GV. 26, LI. 4, ST. 36 and SP. 6. In the control study, needle location was chosen on a non-meridian focus 1 cm posterior to the right fibular head. All images were spatially normalized, and the differences between rest and acupuncture stimulation were statistically analyzed using SPM$^{(R)}$ for Windows$^{(R)}$. Results: Acupuncture applied at acupoint GV. 20 increased rCBF in both the anterior frontal lobes, the right frontotemporal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at GV 26 increased rCBF in the left prefrontal cortex. Acupuncture at LI. 4 increased rCBF in the left prefrontal and both the inferior frontal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at ST. 36 increased rCBF in the left anterior temporal lobe, the right inferior frontal lobes, and the left cerebellum. Acupuncture at SP. 6 increased rCBF in the left inferior frontal and anterior temporal lobes. In the control stimulation, no significant rCBF increase was observed. Conclusion: The results demonstrated a correlation between stimulation at each acupoint with increase in rCBF to the corresponding brain areas.

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