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Jung YH, Kim H, Seo S, Lee D, Lee JY, Moon JY, Cheon GJ, Choi SH, Kang DH. Central metabolites and peripheral parameters associated neuroinflammation in fibromyalgia patients: A preliminary study. Medicine (Baltimore) 2023; 102:e33305. [PMID: 37000093 PMCID: PMC10063264 DOI: 10.1097/md.0000000000033305] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/18/2022] [Accepted: 11/18/2022] [Indexed: 04/01/2023] Open
Abstract
To identify central metabolites and peripheral measures associated with neuroinflammation in fibromyalgia (FM), we scanned [11C]-(R)-PK11195 positron emission tomography and magnetic resonance spectroscopy in FM patients. We measured associations between neurometabolite levels measured by magnetic resonance spectroscopy and the extent of neuroinflammation inferred by the distribution volume ratios of [11C]-(R)-PK11195 positron emission tomography in 12 FM patients and 13 healthy controls. We also examined the associations between peripheral parameters, such as creatinine and C-reactive protein, and neuroinflammation. In FM patients, we found negative correlations between neuroinflammation and the creatine (Cr)/total creatine (tCr; Cr + phosphocreatine) ratios in the right (r = -0.708, P = .015) and left thalamus (r = -0.718, P = .008). In FM patients, negative correlations were apparent between neuroinflammation and the glutamate/tCr ratio in the right insula (r = -0.746, P = .005). In FM patients, we found negative correlations between neuroinflammation in the left thalamus (r = -0.601, P = .039) and left insula (r = -0.598, P = .040) and the blood creatinine levels. Additionally, we found significant correlations of other peripheral measures with neuroinflammation in FM patients. Our results suggest that both central metabolites, such as Cr and glutamate, and peripheral creatinine and other parameters are associated with neuroinflammation in patients with FM.
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Affiliation(s)
- Ye-Ha Jung
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Hyeonjin Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Seongho Seo
- Department of Electronic Engineering, Pai Chai University, Daejeon, Republic of Korea
| | - Dasom Lee
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jae-Yeon Lee
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jee Youn Moon
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Gi Jeong Cheon
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Soo-Hee Choi
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Psychiatry, Seoul National University College of Medicine and Institute of Human Behavioral Medicine, SNU-MRC, Seoul, Republic of Korea
| | - Do-Hyung Kang
- Seoul Chung Psychiatry Clinic, Seoul, Republic of Korea
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Aslam S, Damodaran N, Rajeshkannan R, Sarma M, Gopinath S, Pillai A. Asymmetry index in anatomically symmetrized FDG-PET for improved epileptogenic focus detection in pharmacoresistant epilepsy. J Neurosurg 2023; 138:828-836. [PMID: 35932262 DOI: 10.3171/2022.6.jns22717] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/02/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Positron emission tomography (PET) imaging has assumed an essential role in the presurgical evaluation of epileptogenic foci in drug-resistant epilepsy by identifying the hypometabolic cerebral cortex. The authors herein designed a pilot study to test a novel technique of PET asymmetry after anatomical symmetrization coregistered to MRI (PASCOM), utilizing interhemispheric metabolic asymmetry on interictal fluorine 18-labeled fluorodeoxyglucose (FDG)-PET to better localize the epileptogenic zone. METHODS The authors analyzed interictal FDG-PET scans from 23 patients with drug-resistant epilepsy, mean (± SD) age 20.9 ± 13.1 years old, who had an Engel class I postsurgical outcome while followed up for > 12 months. T1-weighted and FLAIR MRI were used to create a patient-specific, structurally symmetrical template. The asymmetry index (AI) image was computed to detect the cerebral region of hypometabolism using different z-score threshold criteria to optimize sensitivity and specificity. The detected regions were compared with the resection cavity on postoperative MRI using predefined anatomical labels. PASCOM was compared with the visual analysis of FDG-PET by a nuclear medicine consultant blinded to other clinical data (VIS) and visual analysis during multidisciplinary team discussion (MDT). The efficacy of each technique was compared based on a performance score (S), sensitivity, specificity, and correct lateralization of epileptogenicity. RESULTS The mean S was maximum (1.30 ± 1.23) for AI images when thresholded at z > 4 and retaining the cluster of more than 100 voxels containing the peak AI value (Z4C) with 73.03% sensitivity and 96.43% specificity. The mean S was minimum for VIS (0.27 ± 0.31). The mean sensitivity was maximum for MDT (85.04%) and minimum for Z5C (AI images thresholded at z > 5 and clustered; 59.47%), whereas the mean specificity was maximum for Z5C (97.77%) and minimum for VIS (64.60%). Z3C (AI images thresholded at z > 3 and clustered) and Z4C were able to correctly identify the side of epileptogenicity in all the patients. CONCLUSIONS The PASCOM technique with a Z4C threshold had a maximum performance score with good sensitivity and specificity in localizing and lateralizing the epileptogenic zone. The described technique outperformed the conventional visual analysis of FDG-PET and hence warrants further prospective verification.
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Affiliation(s)
| | | | | | - Manjit Sarma
- 4Nuclear Medicine, Amrita Advanced Centre for Epilepsy, Amrita Institute of Medical Sciences & Research Center, Kochi, Kerala, India
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Kim JS, Son HJ, Oh M, Lee DY, Kim HW, Oh J. 60 Years of Achievements by KSNM in Neuroimaging Research. Nucl Med Mol Imaging 2022; 56:3-16. [PMID: 35186156 PMCID: PMC8828843 DOI: 10.1007/s13139-021-00727-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/01/2021] [Accepted: 12/07/2021] [Indexed: 02/03/2023] Open
Abstract
Nuclear medicine neuroimaging is able to show functional and molecular biologic abnormalities in various neuropsychiatric diseases. Therefore, it has played important roles in the clinical diagnosis and in research on the normal and pathological states of the brain. More than 400 outstanding studies have been conducted by Korean researchers over the past 60 years. In the 1990s, when multiheaded single-photon emission computed tomography (SPECT) scanners were first introduced in South Korea, stroke research using brain perfusion SPECT was conducted. With the spread of positron emission tomography (PET) scanners in the 2000s, research on the clinical usefulness of PET and the evaluation of pathophysiology in various diseases such as epilepsy, brain tumors, degenerative brain diseases, and other neuropsychiatric diseases were actively conducted using [18F]FDG and various neuroreceptor tracers. In the 2010s, with the clinical application of new radiopharmaceuticals for amyloid and tau imaging, research demonstrating the clinical usefulness of PET imaging and the pathophysiology of dementia has increased rapidly. It is expected that the role of nuclear medicine will expand with the development of new radiopharmaceuticals and analysis technologies, along with the application of artificial intelligence for early and differential diagnosis, and the development of therapeutic agents for degenerative brain diseases.
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Affiliation(s)
- Jae Seung Kim
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hye Joo Son
- Department of Nuclear Medicine, Dankook University College of Medicine, Cheonan, Republic of Korea
| | - Minyoung Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Dong Yun Lee
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hae Won Kim
- Department of Nuclear Medicine, Keimyung University Dongsan Hospital, Daegu, Republic of Korea
| | - Jungsu Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
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Whi W, Choi H, Paeng JC, Cheon GJ, Kang KW, Lee DS. Fully automated identification of brain abnormality from whole-body FDG-PET imaging using deep learning-based brain extraction and statistical parametric mapping. EJNMMI Phys 2021; 8:79. [PMID: 34778923 PMCID: PMC8590988 DOI: 10.1186/s40658-021-00424-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 10/29/2021] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The whole brain is often covered in [18F]Fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) in oncology patients, but the covered brain abnormality is typically screened by visual interpretation without quantitative analysis in clinical practice. In this study, we aimed to develop a fully automated quantitative interpretation pipeline of brain volume from an oncology PET image. METHOD We retrospectively collected 500 oncologic [18F]FDG-PET scans for training and validation of the automated brain extractor. We trained the model for extracting brain volume with two manually drawn bounding boxes on maximal intensity projection images. ResNet-50, a 2-D convolutional neural network (CNN), was used for the model training. The brain volume was automatically extracted using the CNN model and spatially normalized. For validation of the trained model and an application of this automated analytic method, we enrolled 24 subjects with small cell lung cancer (SCLC) and performed voxel-wise two-sample T test for automatic detection of metastatic lesions. RESULT The deep learning-based brain extractor successfully identified the existence of whole-brain volume, with an accuracy of 98% for the validation set. The performance of extracting the brain measured by the intersection-over-union of 3-D bounding boxes was 72.9 ± 12.5% for the validation set. As an example of the application to automatically identify brain abnormality, this approach successfully identified the metastatic lesions in three of the four cases of SCLC patients with brain metastasis. CONCLUSION Based on the deep learning-based model, extraction of the brain volume from whole-body PET was successfully performed. We suggest this fully automated approach could be used for the quantitative analysis of brain metabolic patterns to identify abnormalities during clinical interpretation of oncologic PET studies.
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Affiliation(s)
- Wonseok Whi
- Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul National University, Seoul, 03080, Republic of Korea
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Hongyoon Choi
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Jin Chul Paeng
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Gi Jeong Cheon
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Keon Wook Kang
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
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Accurate Transmission-Less Attenuation Correction Method for Amyloid-β Brain PET Using Deep Neural Network. ELECTRONICS 2021. [DOI: 10.3390/electronics10151836] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The lack of physically measured attenuation maps (μ-maps) for attenuation and scatter correction is an important technical challenge in brain-dedicated stand-alone positron emission tomography (PET) scanners. The accuracy of the calculated attenuation correction is limited by the nonuniformity of tissue composition due to pathologic conditions and the complex structure of facial bones. The aim of this study is to develop an accurate transmission-less attenuation correction method for amyloid-β (Aβ) brain PET studies. We investigated the validity of a deep convolutional neural network trained to produce a CT-derived μ-map (μ-CT) from simultaneously reconstructed activity and attenuation maps using the MLAA (maximum likelihood reconstruction of activity and attenuation) algorithm for Aβ brain PET. The performance of three different structures of U-net models (2D, 2.5D, and 3D) were compared. The U-net models generated less noisy and more uniform μ-maps than MLAA μ-maps. Among the three different U-net models, the patch-based 3D U-net model reduced noise and cross-talk artifacts more effectively. The Dice similarity coefficients between the μ-map generated using 3D U-net and μ-CT in bone and air segments were 0.83 and 0.67. All three U-net models showed better voxel-wise correlation of the μ-maps compared to MLAA. The patch-based 3D U-net model was the best. While the uptake value of MLAA yielded a high percentage error of 20% or more, the uptake value of 3D U-nets yielded the lowest percentage error within 5%. The proposed deep learning approach that requires no transmission data, anatomic image, or atlas/template for PET attenuation correction remarkably enhanced the quantitative accuracy of the simultaneously estimated MLAA μ-maps from Aβ brain PET.
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Abnormal neuroinflammation in fibromyalgia and CRPS using [11C]-(R)-PK11195 PET. PLoS One 2021; 16:e0246152. [PMID: 33556139 PMCID: PMC7870009 DOI: 10.1371/journal.pone.0246152] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/15/2021] [Indexed: 11/19/2022] Open
Abstract
Purpose Fibromyalgia (FM) and complex regional pain syndrome (CRPS) share many pathological mechanisms related to chronic pain and neuroinflammation, which may contribute to the multifactorial pathological mechanisms in both FM and CRPS. The aim of this study was to assess neuroinflammation in FM patients compared with that in patients with CRPS and healthy controls. Methods Neuroinflammation was measured as the distribution volume ratio (DVR) of [11C]-(R)-PK11195 positron emission tomography (PET) in 12 FM patients, 11 patients with CRPS and 15 healthy controls. Results Neuroinflammation in FM patients was significantly higher in the left pre (primary motor cortex) and post (primary somatosensory cortex) central gyri (p < 0.001), right postcentral gyrus (p < 0.005), left superior parietal and superior frontal gyri (p < 0.005), left precuneus (p < 0.01), and left medial frontal gyrus (p = 0.036) compared with healthy controls. Furthermore, the DVR of [11C]-(R)-PK11195 in FM patients demonstrated decreased neuroinflammation in the medulla (p < 0.005), left superior temporal gyrus (p < 0.005), and left amygdala (p = 0.020) compared with healthy controls. Conclusions To the authors’ knowledge, this report is the first to describe abnormal neuroinflammation levels in the brains of FM patients compared with that in patients with CRPS using [11C]-(R)-PK11195 PET. The results suggested that abnormal neuroinflammation can be an important pathological factor in FM. In addition, the identification of common and different critical regions related to abnormal neuroinflammation in FM, compared with patients with CRPS and healthy controls, may contribute to improved diagnosis and the development of effective medical treatment for patients with FM.
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Niñerola-Baizán A, Aguiar P, Cabrera-Martín M, Vigil C, Gómez-Grande A, Lorenzo C, Rubí S, Sopena P, Camacho V. Relevance of quantification in brain PET studies with 18F-FDG. Rev Esp Med Nucl Imagen Mol 2020. [DOI: 10.1016/j.remnie.2020.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Niñerola-Baizán A, Aguiar P, Cabrera-Martín MN, Vigil C, Gómez-Grande A, Lorenzo C, Rubí S, Sopena P, Camacho V. Relevance of quantification in brain PET studies with 18F-FDG. Rev Esp Med Nucl Imagen Mol 2020; 39:184-192. [PMID: 32345572 DOI: 10.1016/j.remn.2020.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 12/14/2022]
Abstract
The inclusion of 18F-FDG PET as a biomarker in the diagnostic criteria of neurodegenerative diseases and its indication in the presurgical assessment for drug-resistant epilepsies allow to improve specificity of these diagnosis. The traditional interpretation of neurological PET studies has been performed qualitatively, although in the last decade, several quantitative evaluation methods have emerged. This technical development has become relevant in clinical practice, improving specificity, reproducibility and reducing the interrater reliability derived from visual analysis. In this article we update/review the main imaging processing techniques currently used. This may allow the Nuclear Medicine physician to know their advantages and disadvantages when including these procedures in daily clinical practice.
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Affiliation(s)
- A Niñerola-Baizán
- Servicio de Medicina Nuclear, Hospital Clínic, Barcelona, España; Grupo de Imagen Biomédica, Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, España
| | - P Aguiar
- Grupo de Imaxe Molecular e Física Médica, Departamento de Radioloxía, Facultade de Medicina, Universidade de Santiago de Compostela, Santiago de Compostela, España; Servicio de Medicina Nuclear, Hospital Clínico de Santiago de Compostela, Instituto de Investigación Sanitaria de Santiago, Santiago de Compostela, España
| | - M N Cabrera-Martín
- Servicio de Medicina Nuclear, Hospital Clínico San Carlos, Madrid, España
| | - C Vigil
- Servicio Medicina Nuclear, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, España.
| | - A Gómez-Grande
- Servicio de Medicina Nuclear, Hospital Universitario 12 de Octubre, Madrid, España
| | - C Lorenzo
- Servicio de Medicina Nuclear, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, España
| | - S Rubí
- Servicio de Medicina Nuclear, Hospital Universitari Son Espases, Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, España
| | - P Sopena
- Servicio de Medicina Nuclear, Hospital Vithas-Nisa 9 de Octubre, Valencia, España; Servicio de Medicina Nuclear, Hospital Universitario y Politécnico La Fe, Valencia, España
| | - V Camacho
- Servicio de Medicina Nuclear, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, España
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Abstract
PURPOSE We propose a multi-atlas based segmentation method for cardiac PET and SPECT images to deal with the high variability of tracer uptake characteristics in myocardium. In addition, we verify its performance by comparing it to the manual segmentation and single-atlas based approach, using dynamic myocardial PET. METHODS Twelve left coronary artery ligated SD rats underwent ([18F]fluoropentyl) triphenylphosphonium salt PET/CT scans. Atlas-based segmentation is based on the spatial normalized template with pre-defined region-of-interest (ROI) for each anatomical or functional structure. To generate multiple left ventricular (LV) atlases, each LV image was segmented manually and divided into angular segments. The segmentation methods performances were compared in regional count information using leave-one-out cross-validation. Additionally, the polar-maps of kinetic parameters were estimated. RESULTS In all images, the highest r2 template yielded the lowest root-mean-square error (RMSE) between the source image and the best-matching templates ranged between 0.91-0.97 and 0.06-0.11, respectively. The single-atlas and multi-atlas based ROIs yielded remarkably different perfusion distributions: only the multi-atlas based segmentation showed equivalent high correlation results (r2 = 0.92) with the manual segmentation compared with the single-atlas based (r2 = 0.88). The high perfusion value underestimation was remarkable in single-atlas based segmentation. CONCLUSIONS The main advantage of the proposed multi-atlas based cardiac segmentation method is that it does not require any prior information on the tracer distribution to be incorporated into the image segmentation algorithms. Therefore, the same procedure suggested here is applicable to any other cardiac PET or SPECT imaging agents without modification.
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Kang SK, Seo S, Shin SA, Byun MS, Lee DY, Kim YK, Lee DS, Lee JS. Adaptive template generation for amyloid PET using a deep learning approach. Hum Brain Mapp 2018; 39:3769-3778. [PMID: 29752765 PMCID: PMC6866631 DOI: 10.1002/hbm.24210] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 12/26/2022] Open
Abstract
Accurate spatial normalization (SN) of amyloid positron emission tomography (PET) images for Alzheimer's disease assessment without coregistered anatomical magnetic resonance imaging (MRI) of the same individual is technically challenging. In this study, we applied deep neural networks to generate individually adaptive PET templates for robust and accurate SN of amyloid PET without using matched 3D MR images. Using 681 pairs of simultaneously acquired 11 C-PIB PET and T1-weighted 3D MRI scans of AD, MCI, and cognitively normal subjects, we trained and tested two deep neural networks [convolutional auto-encoder (CAE) and generative adversarial network (GAN)] that produce adaptive best PET templates. More specifically, the networks were trained using 685,100 pieces of augmented data generated by rotating 527 randomly selected datasets and validated using 154 datasets. The input to the supervised neural networks was the 3D PET volume in native space and the label was the spatially normalized 3D PET image using the transformation parameters obtained from MRI-based SN. The proposed deep learning approach significantly enhanced the quantitative accuracy of MRI-less amyloid PET assessment by reducing the SN error observed when an average amyloid PET template is used. Given an input image, the trained deep neural networks rapidly provide individually adaptive 3D PET templates without any discontinuity between the slices (in 0.02 s). As the proposed method does not require 3D MRI for the SN of PET images, it has great potential for use in routine analysis of amyloid PET images in clinical practice and research.
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Affiliation(s)
- Seung Kwan Kang
- Department of Biomedical SciencesSeoul National UniversitySeoulKorea
- Department of Nuclear MedicineSeoul National UniversitySeoulKorea
| | - Seongho Seo
- Department of Neuroscience, College of MedicineGachon UniversityIncheonKorea
| | - Seong A. Shin
- Department of Biomedical SciencesSeoul National UniversitySeoulKorea
- Department of Nuclear MedicineSeoul National University Boramae Medical CenterSeoulKorea
| | - Min Soo Byun
- Department of NeuropsychiatrySeoul National UniversitySeoulKorea
| | - Dong Young Lee
- Department of NeuropsychiatrySeoul National UniversitySeoulKorea
| | - Yu Kyeong Kim
- Department of Nuclear MedicineSeoul National University Boramae Medical CenterSeoulKorea
| | - Dong Soo Lee
- Department of Nuclear MedicineSeoul National UniversitySeoulKorea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and TechnologySeoul National UniversitySuwonKorea
- Institute of Radiation MedicineMedical Research Center, Seoul National UniversitySeoulKorea
| | - Jae Sung Lee
- Department of Biomedical SciencesSeoul National UniversitySeoulKorea
- Department of Nuclear MedicineSeoul National UniversitySeoulKorea
- Institute of Radiation MedicineMedical Research Center, Seoul National UniversitySeoulKorea
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Jung YH, Kim H, Jeon SY, Kwon JM, Lee WJ, Kim YC, Jang JH, Choi SH, Lee JY, Kang DH. Brain Metabolites and Peripheral Biomarkers Associated with Neuroinflammation in Complex Regional Pain Syndrome Using [11C]-(R)-PK11195 Positron Emission Tomography and Magnetic Resonance Spectroscopy: A Pilot Study. PAIN MEDICINE 2018; 20:504-514. [DOI: 10.1093/pm/pny111] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Ye-Ha Jung
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Korea
| | - Hyeonjin Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Korea
| | - So Yeon Jeon
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Korea
| | - Jeong Min Kwon
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Won Joon Lee
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Korea
| | - Yong Chul Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Korea
| | - Joon Hwan Jang
- Department of Psychiatry, Seoul National University College of Medicine, Seoul, Korea
| | - Soo-Hee Choi
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Korea
- Department of Psychiatry and Institute of Human Behavioral Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Jun-Young Lee
- Department of Psychiatry and Behavioral Science, Seoul National University College of Medicine & SMG-SNU Boramae Medical Center, Seoul, Korea
| | - Do-Hyung Kang
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Korea
- Department of Psychiatry, Seoul National University College of Medicine, Seoul, Korea
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Hwang D, Kim KY, Kang SK, Seo S, Paeng JC, Lee DS, Lee JS. Improving the Accuracy of Simultaneously Reconstructed Activity and Attenuation Maps Using Deep Learning. J Nucl Med 2018; 59:1624-1629. [DOI: 10.2967/jnumed.117.202317] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/25/2018] [Indexed: 12/25/2022] Open
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Regional Differences in Serotonin Transporter Occupancy by Escitalopram: An [ 11C]DASB PK-PD Study. Clin Pharmacokinet 2017; 56:371-381. [PMID: 27557550 DOI: 10.1007/s40262-016-0444-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND AND OBJECTIVE Escitalopram is one of the most commonly prescribed selective serotonin reuptake inhibitors (SSRIs). It is thought to act by blocking the serotonin transporter (SERT). However, its dose-SERT occupancy relationship is not well known, so it is not clear what level of SERT blockade is achieved by currently approved doses. METHODS To determine the dose-occupancy relationship, we measured serial SERT occupancy using [11C]DASB [3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile] positron emission tomography (PET) and plasma drug concentrations after the administration of escitalopram in 12 healthy volunteers. We then built a pharmacokinetic-pharmacodynamic model to characterize the dose-occupancy relationship in the putamen and the dorsal raphe nucleus. RESULTS Escitalopram at approved doses occupied less SERT than expected and the SERT occupancy showed regional effects [occupancy was higher in the dorsal raphe nucleus than in the putamen (p < 0.001)]. The drug concentration when 50 % of receptors are occupied (EC50) value and Hill coefficient were significantly different between the putamen (EC50 4.30, Hill coefficient 0.459) and the dorsal raphe nucleus (EC50 2.89, Hill coefficient 0.817). CONCLUSIONS Higher doses of escitalopram than 20 mg are needed to achieve 80 % or greater SERT occupancy. Higher occupancy by escitalopram in the dorsal raphe nucleus relative to the striatum may explain the delayed onset of action of SSRIs by modulating autoreceptor function. The prevention of the 5-HT1A autoreceptor-mediated negative feedback could be a strategy for accelerating the clinical antidepressant effects.
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Jeon SY, Seo S, Lee JS, Choi SH, Lee DH, Jung YH, Song MK, Lee KJ, Kim YC, Kwon HW, Im HJ, Lee DS, Cheon GJ, Kang DH. [11C]-(R)-PK11195 positron emission tomography in patients with complex regional pain syndrome: A pilot study. Medicine (Baltimore) 2017; 96:e5735. [PMID: 28072713 PMCID: PMC5228673 DOI: 10.1097/md.0000000000005735] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Complex regional pain syndrome (CRPS) is characterized by severe and chronic pain, but the pathophysiology of this disease are not clearly understood. The primary aim of our case-control study was to explore neuroinflammation in patients with CRPS using positron emission tomography (PET), with an 18-kDa translocator protein specific radioligand [C]-(R)-PK11195. [C]-(R)-PK11195 PET scans were acquired for 11 patients with CRPS (30-55 years) and 12 control subjects (30-52 years). Parametric image of distribution volume ratio (DVR) for each participant was generated by applying a relative equilibrium-based graphical analysis. The DVR of [C]-(R)-PK11195 in the caudate nucleus (t(21) = -3.209, P = 0.004), putamen (t(21) = -2.492, P = 0.022), nucleus accumbens (t(21) = -2.218, P = 0.040), and thalamus (t(21) = -2.395, P = 0.026) were significantly higher in CRPS patients than in healthy controls. Those of globus pallidus (t(21) = -2.045, P = 0.054) tended to be higher in CRPS patients than in healthy controls. In patients with CRPS, there was a positive correlation between the DVR of [C]-(R)-PK11195 in the caudate nucleus and the pain score, the visual analog scale (r = 0.661, P = 0.026, R = 0.408) and affective subscales of McGill Pain Questionnaire (r = 0.604, P = 0.049, R = 0.364). We demonstrated that neuroinflammation of CRPS patients in basal ganglia. Our results suggest that microglial pathology can be an important pathophysiology of CRPS. Association between the level of caudate nucleus and pain severity indicated that neuroinflammation in this region might play a key role. These results may be essential for developing effective medical treatments.
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Affiliation(s)
- So Yeon Jeon
- Department of Neuropsychiatry, Seoul National University Hospital
| | - Seongho Seo
- Department of Nuclear Medicine, Seoul National University College of Medicine
- Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences
| | - Jae Sung Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine
- Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences
- Institute of Radiation Medicine, Medical Research Center
| | - Soo-Hee Choi
- Department of Neuropsychiatry, Seoul National University Hospital
- Department of Psychiatry, Seoul National University College of Medicine
| | - Do-Hyeong Lee
- Department of Neuropsychiatry, Seoul National University Hospital
| | - Ye-Ha Jung
- Department of Neuropsychiatry, Seoul National University Hospital
| | - Man-Kyu Song
- Department of Neuropsychiatry, Seoul National University Hospital
| | - Kyung-Jun Lee
- Department of Neuropsychiatry, Seoul National University Hospital
| | - Yong Chul Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul
| | - Hyun Woo Kwon
- Department of Nuclear Medicine, Seoul National University College of Medicine
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Republic of Korea
| | - Hyung-Jun Im
- Department of Nuclear Medicine, Seoul National University College of Medicine
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Republic of Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Republic of Korea
| | - Gi Jeong Cheon
- Department of Nuclear Medicine, Seoul National University College of Medicine
- Institute of Radiation Medicine, Medical Research Center
| | - Do-Hyung Kang
- Department of Neuropsychiatry, Seoul National University Hospital
- Department of Psychiatry, Seoul National University College of Medicine
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Kim E, Howes OD, Park JW, Kim SN, Shin SA, Kim BH, Turkheimer FE, Lee YS, Kwon JS. Altered serotonin transporter binding potential in patients with obsessive-compulsive disorder under escitalopram treatment: [11C]DASB PET study. Psychol Med 2016; 46:357-366. [PMID: 26423910 DOI: 10.1017/s0033291715001865] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Obsessive-compulsive disorder (OCD) is a chronic, relapsing mental illness. Selective serotonin reuptake inhibitors block serotonin transporters (SERTs) and are the mainstay of treatment for OCD. SERT abnormalities are reported in drug-free patients with OCD, but it is not known what happens to SERT levels during treatment. This is important as alterations in SERT levels in patients under treatment could underlie poor response, or relapse during or after treatment. The aim of the present study was first to validate a novel approach to measuring SERT levels in people taking treatment and then to investigate SERT binding potential (BP) using [11C]DASB PET in patients with OCD currently treated with escitalopram in comparison with healthy controls. METHOD Twelve patients and age- and sex-matched healthy controls were enrolled. The patients and healthy controls underwent serial PET scans after administration of escitalopram and blood samples for drug concentrations were collected simultaneously with the scans. Drug-free BPs were obtained by using an inhibitory E max model we developed previously. RESULTS The inhibitory E max model was able to accurately predict drug-free SERT BP in people taking drug treatment. The drug-free BP in patients with OCD currently treated with escitalopram was significantly different from those in healthy volunteers [Cohen's d = 0.03 (caudate), 1.16 (putamen), 1.46 (thalamus), -5.67 (dorsal raphe nucleus)]. CONCLUSIONS This result extends previous findings showing SERT abnormalities in drug-free patients with OCD by indicating that altered SERT availability is seen in OCD despite treatment. This could account for poor response and the high risk of relapse in OCD.
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Affiliation(s)
- E Kim
- Department of Neuropsychiatry,Seoul National University Bundang Hospital,Gyeonggi-do,Korea
| | - O D Howes
- Psychiatric Imaging,Medical Research Council Clinical Sciences Centre,Imperial College London,Hammersmith Hospital Campus,London,UK
| | - J W Park
- Department of Psychiatry,Seoul National University College of Medicine,Seoul,Korea
| | - S N Kim
- Department of Psychiatry,Seoul National University College of Medicine,Seoul,Korea
| | - S A Shin
- Department of Biomedical Sciences,Seoul National University,Seoul,Korea
| | - B-H Kim
- Department of Clinical Pharmacology and Therapeutics,Kyung Hee University College of Medicine and Hospital,Seoul,Korea
| | - F E Turkheimer
- King's College London, Institute of Psychiatry,London,UK
| | - Y-S Lee
- Department of Nuclear Medicine,Seoul National University College of Medicine,Seoul,Korea
| | - J S Kwon
- Department of Psychiatry,Seoul National University College of Medicine,Seoul,Korea
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16
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Stylianou P, Kimchi G, Hoffmann C, Blat I, Harnof S. Neuroimaging for patient selection for medial temporal lobe epilepsy surgery: Part 2 functional neuroimaging. J Clin Neurosci 2016; 23:23-33. [DOI: 10.1016/j.jocn.2015.04.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/11/2015] [Accepted: 04/18/2015] [Indexed: 11/17/2022]
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17
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Shin JW, Chu K, Shin SA, Jung KH, Lee ST, Lee YS, Moon J, Lee DY, Lee JS, Lee DS, Lee SK. Clinical Applications of Simultaneous PET/MR Imaging Using (R)-[11C]-Verapamil with Cyclosporin A: Preliminary Results on a Surrogate Marker of Drug-Resistant Epilepsy. AJNR Am J Neuroradiol 2015; 37:600-6. [PMID: 26585254 DOI: 10.3174/ajnr.a4566] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 08/17/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The development of resistance to antiepileptic drugs is explained well by the transporter hypothesis, which suggests that drug resistance is caused by inadequate penetration of drugs into the brain barrier as a result of increased levels of efflux transporter such as p-glycoprotein. To evaluate the brain expression of p-glycoprotein in patients with drug-resistant epilepsy, including neocortical epilepsy, we developed a noninvsive quantitative analysis including asymmetry indices based on (R)-[(11)C]-verapamil PET/MR imaging with cyclosporin A, a p-glycoprotein inhibitor. MATERIALS AND METHODS Six patients with drug-resistant epilepsy, 5 patients with drug-sensitive epilepsy, and 8 healthy controls underwent dynamic (R)-[(11)C]-verapamil PET/MR imaging with an intravenous infusion of cyclosporin A. Asymmetry indices [(Right Region - Left Region)/(Right Region + Left Region) × 200%] of the standard uptake values in each of the paired lobes were calculated. RESULTS All patients with drug-resistant epilepsy had significantly different asymmetry from the healthy controls, whereas all patients with drug-sensitive epilepsy had asymmetry similar to that in healthy controls. In the temporal lobe, the asymmetry indices of patients with left temporal lobe drug-resistant epilepsy were more positive than those of healthy controls (healthy controls: 4.0413 ± 1.7452; patients: 7.2184 ± 1.8237; P = .048), and those of patients with right temporal drug-resistant epilepsy were more negative (patients: -1.6496 ± 3.4136; P = .044). In addition, specific regions that had significant asymmetry were different between the lateral and medial temporal lobe epilepsy groups. In the frontal lobe, the asymmetry index of patients with right frontal lobe drug-resistant epilepsy was more negative than that in healthy controls. CONCLUSIONS We confirmed that statistical parametric mapping analysis by using asymmetry indices of (R)-[(11)C]-verapamil PET/MR imaging with cyclosporin A could be used as a surrogate marker for drug-resistant epilepsy, and this approach might be helpful for localizing or lateralizing the epileptic zone.
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Affiliation(s)
- J-W Shin
- From the Department of Neurology (J.-W.S., K.C., K.-H.J., S.-T.L., J.M., D.Y.L., S.K.L.), Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute Department of Neurology (J.-W.S.), CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - K Chu
- From the Department of Neurology (J.-W.S., K.C., K.-H.J., S.-T.L., J.M., D.Y.L., S.K.L.), Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute
| | - S A Shin
- Department of Nuclear Medicine (S.A.S., Y.-S.L., J.S.L., D.S.L.) Department of Biomedical Sciences (S.A.S., J.S.L.), Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - K-H Jung
- From the Department of Neurology (J.-W.S., K.C., K.-H.J., S.-T.L., J.M., D.Y.L., S.K.L.), Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute
| | - S-T Lee
- From the Department of Neurology (J.-W.S., K.C., K.-H.J., S.-T.L., J.M., D.Y.L., S.K.L.), Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute
| | - Y-S Lee
- Department of Nuclear Medicine (S.A.S., Y.-S.L., J.S.L., D.S.L.) Department of Molecular Medicine and Biopharmaceutical Sciences (Y.-S.L., D.S.L.), Graduate School of Convergence Science and Technology, Kyunggi, South Korea
| | - J Moon
- From the Department of Neurology (J.-W.S., K.C., K.-H.J., S.-T.L., J.M., D.Y.L., S.K.L.), Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute
| | - D Y Lee
- From the Department of Neurology (J.-W.S., K.C., K.-H.J., S.-T.L., J.M., D.Y.L., S.K.L.), Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute
| | - J S Lee
- Department of Nuclear Medicine (S.A.S., Y.-S.L., J.S.L., D.S.L.) Department of Biomedical Sciences (S.A.S., J.S.L.), Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - D S Lee
- Department of Nuclear Medicine (S.A.S., Y.-S.L., J.S.L., D.S.L.) Department of Molecular Medicine and Biopharmaceutical Sciences (Y.-S.L., D.S.L.), Graduate School of Convergence Science and Technology, Kyunggi, South Korea
| | - S K Lee
- From the Department of Neurology (J.-W.S., K.C., K.-H.J., S.-T.L., J.M., D.Y.L., S.K.L.), Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute
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Lee JY, Seo S, Lee JS, Kim HJ, Kim YK, Jeon BS. Putaminal serotonergic innervation. Neurology 2015; 85:853-60. [DOI: 10.1212/wnl.0000000000001909] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 03/13/2015] [Indexed: 02/02/2023] Open
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Kim JS, Cheon GJ, Lim SM. Presurgical Mapping of Brain Tumors Using Statistical Probabilistic Anatomical Maps. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/jbise.2015.89061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Setoain X, Carreño M, Pavía J, Martí-Fuster B, Campos F, Lomeña F. PET and SPECT in epilepsy. Rev Esp Med Nucl Imagen Mol 2014. [DOI: 10.1016/j.remnie.2014.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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21
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Setoain X, Carreño M, Pavía J, Martí-Fuster B, Campos F, Lomeña F. [PET and SPECT in epilepsy]. Rev Esp Med Nucl Imagen Mol 2014; 33:165-74. [PMID: 24565567 DOI: 10.1016/j.remn.2014.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 01/22/2014] [Accepted: 01/24/2014] [Indexed: 10/25/2022]
Abstract
Epilepsy is one of the most frequent chronic neurological disorders, affecting 1-2% of the population. Patients with complex partial drug resistant episodes may benefit from a surgical treatment consisting in the excision of the epileptogenic area. Localization of the epileptogenic area was classically performed with video-EEG and magnetic resonance (MR). Recently, functional neuroimaging studies of Nuclear Medicine, positron emission tomography (PET) and single photon emission tomography (SPECT) have demonstrated their utility in the localization of the epileptogenic area prior to surgery. Ictal SPECT with brain perfusion tracers show an increase in blood flow in the initial ictal focus, while PET with (18)FDG demonstrates a decrease of glucose metabolism in the interictal functional deficit zone. In this review, the basic principles and methodological characteristics of the SPECT and PET in epilepsy are described. The ictal SPECT injection mechanism, different patterns of perfusion based on the time of ictal, postictal or interictal injection are detailed and the different diagnostic sensitivities of each one of these SPECT are reviewed. Different methods of analysis of the images with substraction and fusion systems with the MR are described. Similarly, the injection methodology, quantification and evaluation of the images of the PET in epilepsy are described. Finally, the main clinical indications of SPECT and PET in temporal and extratemporal epilepsy are detailed.
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Affiliation(s)
- X Setoain
- Servicio de Medicina Nuclear, Hospital Clínic de Barcelona, Barcelona, España; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Grupo de imagen biomédica, Barcelona, España.
| | - M Carreño
- Servicio de Neurología, Hospital Clínic de Barcelona, Barcelona, España
| | - J Pavía
- Servicio de Medicina Nuclear, Hospital Clínic de Barcelona, Barcelona, España; Facultad de Medicina, Universitat de Barcelona, Barcelona, España; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Grupo de imagen biomédica, Barcelona, España
| | - B Martí-Fuster
- Facultad de Medicina, Universitat de Barcelona, Barcelona, España; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Grupo de imagen biomédica, Barcelona, España
| | - F Campos
- Servicio de Medicina Nuclear, Hospital Clínic de Barcelona, Barcelona, España
| | - F Lomeña
- Servicio de Medicina Nuclear, Hospital Clínic de Barcelona, Barcelona, España; Facultad de Medicina, Universitat de Barcelona, Barcelona, España
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22
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The relationship between antipsychotic D2 occupancy and change in frontal metabolism and working memory : A dual [(11)C]raclopride and [(18) F]FDG imaging study with aripiprazole. Psychopharmacology (Berl) 2013; 227:221-9. [PMID: 23271192 DOI: 10.1007/s00213-012-2953-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
Abstract
RATIONALE The effects of aripiprazole on cognitive function are obscure, possibly due to the difficulty in disentangling the specific effects on cognitive function from effects secondary to the improvement of other schizophrenic symptoms. This prompts the necessity of using an intermediate biomarker relating the drug effect on the brain to change in cognitive function. OBJECTIVES To explore the effect of aripiprazole on cognitive function, we measured changes in frontal metabolism as an intermediate biomarker and sought to determine its relationship with D2 receptor occupancy and changes in working memory. METHODS Fifteen healthy male volunteers participated in the study. Serial positron emission tomography (PET) scans with [(11)C]raclopride and [(18) F]FDG were conducted 1 day before and 2 days after the administration of aripiprazole. The subjects performed the N-back task just after finishing the [(18) F]FDG scan. RESULTS The mean (±SD) D2 receptor occupancies were 22.2 ± 16.0 % in the 2 mg group, 35.5 ± 3.6 % in the 5 mg group, 63.2 ± 9.9 % in the 10 mg group and 72.8 ± 2.1 % in the 30 mg group. The frontal metabolism was significantly decreased after the administration of aripiprazole (t = 2.705, df = 14, p = 0.017). Greater striatal D2 receptor occupancy was related to greater decrease in frontal metabolism (r = -0.659, p = 0.010), and greater reduction in frontal metabolism was associated with longer reaction times (r = -0.597, p = 0.019) under the greatest task load. CONCLUSIONS Aripiprazole can affect cognitive function and alter frontal metabolic function. The changes in these functions are linked to greater D2 receptor occupancy. This suggests that it may be important to find the lowest effective dose of aripiprazole in order to prevent adverse cognitive effects.
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Pharmacodynamic analysis of magnetic resonance imaging-monitored focused ultrasound-induced blood-brain barrier opening for drug delivery to brain tumors. BIOMED RESEARCH INTERNATIONAL 2013; 2013:627496. [PMID: 23607093 PMCID: PMC3626247 DOI: 10.1155/2013/627496] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 02/25/2013] [Indexed: 12/22/2022]
Abstract
Microbubble-enhanced focused ultrasound (FUS) can enhance the delivery of therapeutic agents into the brain for brain tumor treatment. The purpose of this study was to investigate the influence of brain tumor conditions on the distribution and dynamics of small molecule leakage into targeted regions of the brain after FUS-BBB opening. A total of 34 animals were used, and the process was monitored by 7T-MRI. Evans blue (EB) dye as well as Gd-DTPA served as small molecule substitutes for evaluation of drug behavior. EB was quantified spectrophotometrically. Spin-spin (R1) relaxometry and area under curve (AUC) were measured by MRI to quantify Gd-DTPA. We found that FUS-BBB opening provided a more significant increase in permeability with small tumors. In contrast, accumulation was much higher in large tumors, independent of FUS. The AUC values of Gd-DTPA were well correlated with EB delivery, suggesting that Gd-DTPA was a good indicator of total small-molecule accumulation in the target region. The peripheral regions of large tumors exhibited similar dynamics of small-molecule leakage after FUS-BBB opening as small tumors, suggesting that FUS-BBB opening may have the most significant permeability-enhancing effect on tumor peripheral. This study provides useful information toward designing an optimized FUS-BBB opening strategy to deliver small-molecule therapeutic agents into brain tumors.
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Kim H, Kim IJ, Kim SJ, Song SH, Pak K, Kim K. Quantification of Tc-99m-ethyl cysteinate dimer brain single photon emission computed tomography images using statistical probabilistic brain atlas in depressive end-stage renal disease patients: Correlation with disease severity and symptom factors. Neural Regen Res 2012; 7:2151-9. [PMID: 25558229 PMCID: PMC4281418 DOI: 10.3969/j.issn.1673-5374.2012.27.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 06/10/2012] [Indexed: 11/18/2022] Open
Abstract
This study adapted a statistical probabilistic anatomical map of the brain for single photon emission computed tomography images of depressive end-stage renal disease patients. This research aimed to investigate the relationship between symptom clusters, disease severity, and cerebral blood flow. Twenty-seven patients (16 males, 11 females) with stages 4 and 5 end-stage renal disease were enrolled, along with 25 healthy controls. All patients underwent depressive mood assessment and brain single photon emission computed tomography. The statistical probabilistic anatomical map images were used to calculate the brain single photon emission computed tomography counts. Asymmetric index was acquired and Pearson correlation analysis was performed to analyze the correlation between symptom factors, severity, and regional cerebral blood flow. The depression factors of the Hamilton Depression Rating Scale showed a negative correlation with cerebral blood flow in the left amygdale. The insomnia factor showed negative correlations with cerebral blood flow in the left amygdala, right superior frontal gyrus, right middle frontal gyrus, and left middle frontal gyrus. The anxiety factor showed a positive correlation with cerebral glucose metabolism in the cerebellar vermis and a negative correlation with cerebral glucose metabolism in the left globus pallidus, right inferior frontal gyrus, both temporal poles, and left parahippocampus. The overall depression severity (total scores of Hamilton Depression Rating Scale) was negatively correlated with the statistical probabilistic anatomical map results in the left amygdala and right inferior frontal gyrus. In conclusion, our results demonstrated that the disease severity and extent of cerebral blood flow quantified by a probabilistic brain atlas was related to various brain areas in terms of the overall severity and symptom factors in end-stage renal disease patients.
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Affiliation(s)
- Heeyoung Kim
- Department of Nuclear Medicine, Pusan National University Hospital, Busan, Republic of Korea
| | - In Joo Kim
- Department of Nuclear Medicine, Pusan National University Hospital, Busan, Republic of Korea ; Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
| | - Seong-Jang Kim
- Department of Nuclear Medicine, Pusan National University Hospital, Busan, Republic of Korea ; Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
| | - Sang Heon Song
- Department of Nuclear Medicine, Pusan National University Hospital, Busan, Republic of Korea ; Department of Internal Medicine, Pusan National University Hospital, Busan, Republic of Korea
| | - Kyoungjune Pak
- Department of Nuclear Medicine, Pusan National University Hospital, Busan, Republic of Korea
| | - Keunyoung Kim
- Department of Nuclear Medicine, Pusan National University Hospital, Busan, Republic of Korea
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25
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Presurgical epilepsy localization with interictal cerebral dysfunction. Epilepsy Behav 2011; 20:194-208. [PMID: 21257351 DOI: 10.1016/j.yebeh.2010.12.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 12/07/2010] [Indexed: 11/22/2022]
Abstract
Localization of interictal cerebral dysfunction with 2-[(18)F]fluoro-2-D-deoxyglucose (FDG) positron emission tomography (PET) and neuropsychological examination usefully supplements electroencephalography (EEG) and brain magnetic resonance imaging (MRI) in planning epilepsy surgery. In MRI-negative mesial temporal lobe epilepsy, correlation of temporal lobe hypometabolism with extracranial ictal EEG can support resection without prior intracranial EEG monitoring. In refractory localization-related epilepsies, hypometabolic sites may supplement other data in hypothesizing likely ictal onset zones in order to intracranial electrodes for ictal recording. Prognostication of postoperative seizure freedom with FDG PET appears to have greater positive than negative predictive value. Neuropsychological evaluation is critical to evaluating the potential benefit of epilepsy surgery. Cortical deficits measured with neuropsychometry are limited in lateralizing and localizing value for determination of ictal onset sites, however. Left temporal resection risks iatrogenic verbal memory deficits and dysnomia, and neuropsychological findings are useful in predicting those at greatest risk. Prognostication of cognitive risks with resection at other sites is less satisfactory.
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del Campo N, Tait RJ, Acosta-Cabronero J, Hong YT, Izquierdo-Garcia D, Smith R, Aigbirhio FI, Sahakian BJ, Müller U, Robbins TW, Fryer TD. Quantification of receptor-ligand binding potential in sub-striatal domains using probabilistic and template regions of interest. Neuroimage 2010; 55:101-12. [PMID: 21126591 DOI: 10.1016/j.neuroimage.2010.11.071] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 11/18/2010] [Accepted: 11/23/2010] [Indexed: 11/19/2022] Open
Abstract
Sub-striatal regions of interest (ROIs) are widely used in PET studies to investigate the role of dopamine in the modulation of neural networks implicated in emotion, cognition and motor function. One common approach is that of Mawlawi et al. (2001) and Martinez et al. (2003), where each striatum is divided into five sub-regions. This study focuses on the use of two spatial normalization-based alternatives to manual sub-striatal ROI delineation per subject: manual ROI delineation on a template brain and the production of probabilistic ROIs from a set of subject-specific manually delineated ROIs. Two spatial normalization algorithms were compared: SPM5 unified segmentation and ART. The ability of these methods to quantify sub-striatal regional non-displaceable binding potential (BP(ND)) and BP(ND) % change (following methylphenidate) was tested on 32 subjects (16 controls and 16 ADHD patients) scanned with the dopamine D(2)/D(3) ligand [(18)F]fallypride. Probabilistic ROIs produced by ART provided the best results, with similarity index values against subject-specific manual ROIs of 0.75-0.89 (mean 0.84) compared to 0.70-0.85 (mean 0.79) for template ROIs. Correlations (r) for BP(ND) and BP(ND) % change between subject-specific manual ROIs and these probabilistic ROIs of 0.90-0.98 (mean 0.95) and 0.98-1.00 (mean 0.99) respectively were superior overall to those obtained with template ROIs, although only marginally so for BP(ND) % change. The significance of relationships between BP(ND) measures and both behavioural tasks and methylphenidate plasma levels was preserved with ART combined with both probabilistic and template ROIs. SPM5 virtually matched the performance of ART for BP(ND) % change estimation but was inferior for BP(ND) estimation in caudate sub-regions. ART spatial normalization combined with probabilistic ROIs and to a lesser extent template ROIs provides an efficient and accurate alternative to time-consuming manual sub-striatal ROI delineation per subject, especially when the parameter of interest is BP(ND) % change.
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Abstract
Traumatic brain injury represents a substantial public health problem for which clinicians have limited treatment avenues. Traditional FDG-positron emission tomography (PET) brain imaging has provided unique insights into this disease including prognostic information. With the advent and implementation of novel tracers as well as improvement in instrumentation, molecular brain imaging using PET can further illustrate traumatic brain injury pathophysiology and point to novel treatment strategies.
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Affiliation(s)
- Jacob G Dubroff
- Division of Nuclear Medicine, Department of Radiology, Hospital of the University of Pennsylvania, Room 110, Donner Building, Philadelphia, PA 19104, USA
| | - Andrew B Newberg
- Division of Nuclear Medicine, Department of Radiology, Hospital of the University of Pennsylvania, Room 110, Donner Building, Philadelphia, PA 19104, USA.
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Didelot A, Ryvlin P, Lothe A, Merlet I, Hammers A, Mauguière F. PET imaging of brain 5-HT1A receptors in the preoperative evaluation of temporal lobe epilepsy. Brain 2008; 131:2751-64. [DOI: 10.1093/brain/awn220] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Adrien Didelot
- Hospices Civils de Lyon, Service de Neurologie Fonctionnelle et d’Épileptologie, Hôpital Pierre Wertheimer, Boulevard Pinel, Lyon F-69003
- Université Lyon 1, Lyon F-69003
- INSERM, U879, Lyon F-69003
- Institut Fédératif des Neurosciences de Lyon, Lyon F-69003
| | - Philippe Ryvlin
- Hospices Civils de Lyon, Service de Neurologie Fonctionnelle et d’Épileptologie, Hôpital Pierre Wertheimer, Boulevard Pinel, Lyon F-69003
- Université Lyon 1, Lyon F-69003
- Institut Fédératif des Neurosciences de Lyon, Lyon F-69003
- CERMEP, Lyon F-69003
- INSERM U821
| | - Amélie Lothe
- Institut Fédératif des Neurosciences de Lyon, Lyon F-69003
- INSERM U821
| | - Isabelle Merlet
- INSERM U642, Rennes F-35042
- Université de Rennes 1, LTSI, Rennes F-35042, France
| | - Alexander Hammers
- MRC Clinical Sciences Centre and Division of Neuroscience, Faculty of Medicine, Imperial College, Hammersmith Hospital, DuCane Road, London, UK
| | - François Mauguière
- Hospices Civils de Lyon, Service de Neurologie Fonctionnelle et d’Épileptologie, Hôpital Pierre Wertheimer, Boulevard Pinel, Lyon F-69003
- Université Lyon 1, Lyon F-69003
- INSERM, U879, Lyon F-69003
- Institut Fédératif des Neurosciences de Lyon, Lyon F-69003
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Rousset OG, Collins DL, Rahmim A, Wong DF. Design and implementation of an automated partial volume correction in PET: application to dopamine receptor quantification in the normal human striatum. J Nucl Med 2008; 49:1097-106. [PMID: 18552147 DOI: 10.2967/jnumed.107.048330] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The considerable effort and potential lack of reproducibility of human-driven PET quantification and partial volume correction (PVC) can be alleviated by use of atlas-based automatic analysis. The present study examined the application of a new algorithm designed to automatically define 3-dimensional regions of interest (ROIs) and their effect on dopamine receptor quantification in the normal human brain striatum, both without and with PVC. METHODS A total of 90 healthy volunteers (age range, 18-46 y) received a single injection of (11)C-raclopride, and automatic segmentation of concomitant structural MR images was performed using a maximum-probability atlas in combination with a trained neural network. For each identified tissue segment considered homogeneous for the tracer (or volumes of interest [VOIs]), an a priori criterion based on minimum axial recovery coefficient (RC(zmin) = 50%, 75%, and 90%) was used to constrain the extent of each ROI. RESULTS With ROIs essentially overlapping the entire VOI volume (obtained with RC(zmin) = 50%), the binding potential (BP(ND)) of (11)C-raclopride was found to be around 2.2 for caudate and 2.9 for putamen, an underestimation by 35% and 28%, respectively, according to PVC values. At increased RC(zmin), BP(ND) estimates of (11)C-raclopride were increased by 12% and 21% for caudate and 8% and 15% for putamen when the associated ROIs decreased to around 65% and 43% of total tissue volume (VOI) for caudate and 67% and 31% for putamen. After PVC, we observed relative increases in BP(ND) variance of 12% for caudate and 20% for putamen, whereas estimated BP(ND) values all increased to 3.4 for caudate and 4.0 for putamen, regardless of ROI size. Dopamine receptor concentrations appeared less heterogeneous in the normal human striatum after PVC than they did without PVC: the 25%-30% difference in BP(ND) estimates observed between caudate and putamen remained significant after PVC but was reduced to slightly less than 20%. Furthermore, the results were comparable with those obtained with a manual method currently in use in our laboratory. CONCLUSION The new algorithm allows for traditional PET data extraction and PVC in an entirely automatic fashion, thus avoiding labor-intensive analyses and potential intra- or interobserver variability. This study also offers the first, to our knowledge, large-scale application of PVC to dopamine D(2)/D(3) receptor imaging with (11)C-raclopride in humans.
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Affiliation(s)
- Olivier G Rousset
- Section of High Resolution Brain PET Imaging, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21287, USA.
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Taq1A polymorphism in the dopamine D2 receptor gene predicts brain metabolic response to aripiprazole in healthy male volunteers. Pharmacogenet Genomics 2008; 18:91-7. [PMID: 18192895 DOI: 10.1097/fpc.0b013e3282f3ef8c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The Taq1A polymorphism in the dopamine D2 receptor (DRD2) gene has been reported to be associated with the pharmacodynamics of antipsychotic drugs. We investigated the metabolic response of glucose in the brain to aripiprazole in relation to the DRD2 Taq1A polymorphism. METHODS Twenty healthy male volunteers were recruited and were divided into two groups of 10 participants, according to their DRD2 genotypes (A1A1, n=10; A2A2, n=10). The volunteers received single oral doses of aripiprazole (10 mg) and a placebo, following a single-blind, placebo-controlled, randomized, two-way crossover study design. Brain glucose metabolism was assessed using positron emission tomography, scanned with 18F-fluorodeoxyglucose 12 h after the administration of the drug or placebo. RESULTS In voxel-based analysis using SPM2, volunteers with the A2A2 genotype showed decreased metabolism in the right middle frontal gyrus, the left middle and inferior frontal gyrus, the right and left inferior temporal gyrus, and the right cingulate gyrus, and increased metabolism in the pons. In contrast, volunteers with the A1A1 genotype exhibited increased metabolism in the right caudate head, and no brain region showed decreased metabolism. In a region-of-interest analysis, significant interactions between drug and genotype were observed in the right medial orbitofrontal gyrus and the left caudate nucleus. CONCLUSIONS This suggests that DRD2 Taq1A polymorphism status may be associated with the clinical response to aripiprazole.
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Abstract
The past decade has seen a surge in the utilization of small animal imaging for epilepsy research. In vivo imaging studies have the potential to provide important insights into the structural and functional correlates of the development and progression of epilepsy in these models. However, the small size of the rodent brain means that anatomic resolution is often relatively poor for many imaging modalities, particularly those providing functional information such as positron emission tomography. Coregistration of these images with those of higher structural resolution, such as MRI, provides an attractive approach to this problem, and also allows correlations between structural and functional imaging data. Image coregistration is commonly utilized in clinical research and practice. However, its application for small animal images has been, to date, relatively under utilized and largely unvalidated. The current review aims to provide an overview of image coregistration methods, particularly for MRI and PET, and their application to imaging of small animal models of epilepsy. Methodological advantages and potential traps are highlighted.
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Affiliation(s)
- Bianca Jupp
- Department of Medicine, Royal Melbourne Hosptial, The University of Melbourne, Parkville, Victoria, Australia.
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Hoehn-Saric R, Lee JS, McLeod DR, Wong DF. Effect of worry on regional cerebral blood flow in nonanxious subjects. Psychiatry Res 2005; 140:259-69. [PMID: 16297605 DOI: 10.1016/j.pscychresns.2005.05.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2004] [Revised: 02/15/2005] [Accepted: 05/25/2005] [Indexed: 11/17/2022]
Abstract
Several studies suggest that cognitive tasks attenuate activation of the limbic system by emotional stimuli. We investigated the possibility that worry would similarly inhibit the limbic system by examining its effects on regional cerebral blood flow (rCBF). Ten nonanxious volunteers underwent four scans within one session, using positron emission tomography (PET) with H(2)(15)O as tracer. The first two scans recorded emotionally neutral thinking induced after listening to tapes describing neutral statements. Preceding the third and fourth scans, subjects listened to the self-recorded tape describing their individual worries, were instructed to continue to worry, and were scanned 5 min later. Subjects rated themselves as more anxious during the worry scans but showed no significant heart interbeat or skin conductance changes. During worry, rCBF increases were found bilaterally in the medial fronto-orbital gyri and the right thalamus; rCBF decreases were found bilaterally in the hippocampi and amygdalae, in the right insula, the left and right inferior, middle and superior temporal gyri and the occipito-temporal gyri, the right inferior occipital gyrus and the left supramarginal gyrus. Activity of the left orbito-frontal gyrus was negatively correlated with activity of the amygdalae. The results support the hypothesis that worry-induced prefrontal activity suppresses affect-related subcortical regions.
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Affiliation(s)
- Rudolf Hoehn-Saric
- Department of Psychiatry, Johns Hopkins School of Medicine, Room 117, Johns Hopkins Hospital, Baltimore, MD 21287, USA.
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Lee JJ, Kang WJ, Lee DS, Lee JS, Hwang H, Kim KJ, Hwang YS, Chung JK, Lee MC. Diagnostic performance of 18F-FDG PET and ictal 99mTc-HMPAO SPET in pediatric temporal lobe epilepsy: quantitative analysis by statistical parametric mapping, statistical probabilistic anatomical map, and subtraction ictal SPET. Seizure 2005; 14:213-20. [PMID: 15797357 DOI: 10.1016/j.seizure.2005.01.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We investigated the diagnostic performance of 18F-FDG PET and ictal (99m)Tc-HMPAO SPET in pediatric temporal lobe epilepsy (TLE). Twenty-one pediatric TLE patients were enrolled in this study. Their diagnoses were confirmed by histology and post-surgical outcome (Engel class I or II). The patients' ages were 18 or younger (15+/-3 years). Of the 21 patients, 21 patients underwent 18F-FDG PET scan and 15 underwent ictal (99m)Tc-HMPAO SPET. Preoperative PET and/or ictal SPET images were reviewed by simple visual assessment and by statistical parametric mapping (SPM). Asymmetric indices (AI) were calculated using statistical probabilistic anatomical map (SPAM) on 18F-FDG PET. In nine patients who underwent both ictal and interictal SPET, SISCOM (subtraction ictal SPET coregistered to MR template) was performed. PET correctly localized epileptogenic zones in 20 of 21 (95%) by visual assessment. SPM analysis of PET correctly localized epileptogenic zones in 18 of 21 (86%). Ictal SPET correctly localized epileptogenic zones in 12 of 15 (80%) by visual assessment. SPM analysis of ictal SPET correctly localized epileptogenic zones in 12 of 15 (80%). SISCOM correctly localized 8 of 9 (89%), which was equal to that of visual assessment of ictal SPET. The AIs of the temporal lobes by PET were -15+/-8.4 in the left and 9.9+/-8.9 in the right TLE (normal control: -2.9+/-2.8), and correctly localized epileptogenic zones in all cases. As is found in adult TLE, PET and ictal SPET efficiently localized epileptogenic zones in pediatric TLE. SPM analysis of PET or ictal SPET could be used as an aid to visual assessment. Moreover, SISCOM was equal visual assessment of ictal SPET images in terms of lesion localizations.
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Affiliation(s)
- Jong Jin Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, 28 Yeongeon-dong, Jongno-gu, Seoul 110-744, South Korea
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Lee JS, Lee DS, Kim YK, Kim J, Lee HY, Lee SK, Chung JK, Lee MC. Probabilistic map of blood flow distribution in the brain from the internal carotid artery. Neuroimage 2005; 23:1422-31. [PMID: 15589106 DOI: 10.1016/j.neuroimage.2004.07.057] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Revised: 07/19/2004] [Accepted: 07/21/2004] [Indexed: 10/26/2022] Open
Abstract
Brain single photon emission computed tomographic (SPECT) images acquired after injecting Tc-99m-HMPAO into the internal carotid artery (ICA) during an intracarotid amobarbital procedure (IAP SPECT) provide anatomical information on the blood flow distribution from the ICA. In this study, probabilistic maps of the distribution of blood supply from the ICA were developed using the IAP SPECT images. Twenty-two sets of basal and IAP SPECT were collected from an existing database. IAP SPECT images were coregistered to basal SPECT images, and spatial normalization parameters used for basal SPECT images were reapplied to IAP SPECT for anatomical standardization. Pixel counts of IAP SPECT images were then normalized, and the probabilistic map of cerebral perfusion distribution (perfusion probabilistic map) for each hemisphere was determined by averaging the spatial/count-normalized IAP SPECT images. Population-based probabilistic maps representing the extent of ICA territory (extent probabilistic map) were also composed by averaging the binary images obtained by thresholding the spatially normalized IAP SPECT images. The probabilistic maps were used to quantify cerebral perfusion and reserve change after arterial bypass surgery in 10 patients with ICA stenosis. In the probabilistic maps, blood supply from the ICA was found to be most likely in the dorsolateral frontal lobe, the anterosuperior portion of the temporal lobe, and in the frontoparietal area. Of the subcortical regions, the striatum was found to be most likely to derive its blood supply from ICA. In patients with cerebral occlusive disease, improvements in basal perfusion and perfusion reserve in the bypass-grafted ICA territory were well identified and were increased by 6.2% and 4.6%, respectively, on average. The probabilistic maps developed in this study illustrate the perfusion distribution and extent of vascular territory for ICA and would be useful for objective evaluations of perfusion status in cerebrovascular disease.
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MESH Headings
- Adolescent
- Adult
- Algorithms
- Amobarbital
- Anterior Temporal Lobectomy
- Brain/blood supply
- Brain/diagnostic imaging
- Carotid Artery, Internal/diagnostic imaging
- Carotid Artery, Internal/surgery
- Carotid Stenosis/diagnostic imaging
- Carotid Stenosis/surgery
- Dominance, Cerebral/physiology
- Epilepsy, Temporal Lobe/diagnostic imaging
- Epilepsy, Temporal Lobe/surgery
- Female
- Humans
- Image Processing, Computer-Assisted
- Imaging, Three-Dimensional
- Magnetic Resonance Imaging
- Male
- Models, Statistical
- Postoperative Complications/diagnostic imaging
- Reference Values
- Regional Blood Flow/physiology
- Retrospective Studies
- Technetium Tc 99m Exametazime
- Tomography, Emission-Computed, Single-Photon
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Affiliation(s)
- Jae Sung Lee
- Department of Nuclear Medicine, Seoul National University, College of Medicine, Seoul 110-744, Korea
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Vik T, Heitz F, Namer I, Armspach JP. On the modeling, construction, and evaluation of a probabilistic atlas of brain perfusion. Neuroimage 2005; 24:1088-98. [PMID: 15670686 DOI: 10.1016/j.neuroimage.2004.10.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 09/07/2004] [Accepted: 10/21/2004] [Indexed: 10/26/2022] Open
Abstract
To detect subtle, abnormal perfusion patterns in brain single photon emission computer tomography (SPECT) images, it is necessary to develop quantitative methods in which computer-aided statistical analysis takes advantage of information present in databases of normal subjects. The purpose of this study was to evaluate and examine aspects of the creation and the modeling power of three statistical models for representing brain perfusion as observed in ECD-SPECT. The first model is a local model of voxel-by-voxel mean and variance. The second model is a PCA-based global model that accounts for covariance patterns in the images. The third model is an original model that is a non-linear extension to the second model. This model is based on robust statistics for modeling abnormalities. To evaluate the models, a leave-one-out procedure combined with simulations of abnormal perfusion patterns was adopted. Abnormal perfusion patterns were simulated at different locations in the brain, with different intensities and different sizes. The procedure yields receiver operator characteristics (ROC) that present a combined measure of model-fit and model-sensitivity at detecting abnormalities. The scheme can further be used to compare models as well as the influence of different preprocessing steps. In particular, the influence of different registration approaches is studied and analyzed. The results show that the original non-linear model always performed better than the other models. Finally, location-dependent detection performance was found. Most notably, a higher variation of perfusion was observed in the right frontal cortex than in the other locations studied.
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Affiliation(s)
- Torbjørn Vik
- Laboratoire des Sciences de l'Image de l'Informatique et de la Télédetection (LSIIT), UMR-7005 CNRS, 67412 Illkirch, France.
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Kang E, Lee DS, Kang H, Lee JS, Oh SH, Lee MC, Kim CS. Age-associated changes of cerebral glucose metabolic activity in both male and female deaf children: parametric analysis using objective volume of interest and voxel-based mapping. Neuroimage 2004; 22:1543-53. [PMID: 15275911 DOI: 10.1016/j.neuroimage.2004.04.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Revised: 03/16/2004] [Accepted: 04/05/2004] [Indexed: 01/18/2023] Open
Abstract
Quantitative analysis of brain activity in the brains of children requires the establishment of age-associated norms. We investigated regional differences in age-associated changes in fluorodeoxyglucose (FDG) uptake in the developmental brains. From 87 (44 male and 43 female) deaf children from the age of 1 to 15, brain FDG positron emission tomography (PET) images were examined after spatial normalization, smoothing, and global normalization to identify brain regions showing a correlation between FDG uptake and age. Using population-based probabilistic volume of interests (VOIs), an objective VOI analysis was performed where normalized relative FDG uptake was measured and their correlations with age were examined in both genders. For the voxel-based analyses, the correlations with age were examined in a general linear model using statistical parametric mapping (SPM99). Both methods revealed that FDG uptake linearly increases with age both in the bilateral inferior prefrontal/orbitofrontal gyri and the right dorsomedial frontal gyrus and decreases in the inferior temporal gyrus and internal capsule white matter. Male children showed age-associated increases of FDG uptake in the right dorsomedial frontal gyrus, and female children in the left dorsolateral prefrontal cortex and thalamus. These changes in FDG uptake in various brain regions may suggest changes in synaptic density or regional activity resulting from normal maturation or deaf-induced adaptation. Caution should be exercised in interpreting the differences in the brain of child patients when compared with adult control's or with a different gender. Further research will be needed to examine if gender difference is manifested in the development rate of behavioral/cognitive functions in association with the age-associated changes of the right medial frontal (male) or the left dorsolateral prefrontal cortices.
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Affiliation(s)
- Eunjoo Kang
- Department of Nuclear Medicine, Seoul National University, 28 Yongun-dong, Jongno-gu, Seoul 110-744, South Korea
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Lee JS, Lee DS, Park KS, Chung JK, Lee MC. Changes in the Heterogeneity of Cerebral Glucose Metabolism with Healthy Aging: Quantitative Assessment by Fractal Analysis. J Neuroimaging 2004. [DOI: 10.1111/j.1552-6569.2004.tb00262.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Park HJ, Levitt J, Shenton ME, Salisbury DF, Kubicki M, Kikinis R, Jolesz FA, McCarley RW. An MRI study of spatial probability brain map differences between first-episode schizophrenia and normal controls. Neuroimage 2004; 22:1231-46. [PMID: 15219595 PMCID: PMC2789267 DOI: 10.1016/j.neuroimage.2004.03.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2003] [Revised: 02/20/2004] [Accepted: 03/04/2004] [Indexed: 10/26/2022] Open
Abstract
We created a spatial probability atlas of schizophrenia to provide information about the neuroanatomic variability of brain regions of patients with the disorder. Probability maps of 16 regions of interest (ROIs) were constructed by taking manually parcellated ROIs from subjects' magnetic resonance images (MRIs) and linearly transforming them into Talairach space using the Montreal Neurological Institute (MNI) template. ROIs included temporal, parietal, and prefrontal cortex subregions, with a principal focus on temporal lobe structures. Subject Ns ranged from 11 to 28 for the different ROIs. Our global measure of the spatial distribution of the transformed ROI was the sum of voxels with 50% overlap among subjects. The superior temporal gyrus (STG) and fusiform gyrus (FG) had lower values for schizophrenic subjects than for normal controls, suggestive of greater spatial variability for these ROIs in schizophrenic subjects. For the computation of statistical significance of group differences in portions of the ROI, we used voxel-wise comparisons and Fisher's exact test. First-episode schizophrenic patients compared with controls showed lower probability (P < 0.05) at dorso-posterior areas of planum temporale and Heschl's gyrus, lateral and anterior regions in the left hippocampus (HIPP), and dorsolateral regions of fusiform gyrus. Importantly, most ROIs of schizophrenic subjects showed a significantly lower spatial overlap than controls, even after nonlinear spatial normalization, suggesting a greater heterogeneity in the spatial distribution of ROIs. There is consequently a need for caution in neuroimaging studies where data from schizophrenic subjects are normalized to a particular stereotaxic coordinate system based on healthy controls. Apparent group differences in activation may simply reflect a greater heterogeneity of spatial distribution in schizophrenia.
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Affiliation(s)
- Hae-Jeong Park
- Clinical Neuroscience Division, Laboratory of Neuroscience, Boston VA Health Care System-Brockton Division, Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
- Surgical Planning Laboratory, MRI Division, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Division of Nuclear Medicine, Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul 120-749, South Korea
| | - James Levitt
- Clinical Neuroscience Division, Laboratory of Neuroscience, Boston VA Health Care System-Brockton Division, Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Martha E. Shenton
- Clinical Neuroscience Division, Laboratory of Neuroscience, Boston VA Health Care System-Brockton Division, Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
- Surgical Planning Laboratory, MRI Division, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Dean F. Salisbury
- Clinical Neuroscience Division, Laboratory of Neuroscience, Boston VA Health Care System-Brockton Division, Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
- Cognitive Neuroscience Laboratory, McLean Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Marek Kubicki
- Clinical Neuroscience Division, Laboratory of Neuroscience, Boston VA Health Care System-Brockton Division, Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
- Surgical Planning Laboratory, MRI Division, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ron Kikinis
- Surgical Planning Laboratory, MRI Division, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ferenc A. Jolesz
- Surgical Planning Laboratory, MRI Division, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Robert W. McCarley
- Clinical Neuroscience Division, Laboratory of Neuroscience, Boston VA Health Care System-Brockton Division, Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
- Corresponding author. Laboratory of Neuroscience, Clinical Neuroscience Division, Boston VA Health Care System-Brockton Division, and Department of Psychiatry, Harvard Medical School, 940 Belmont Street, Brockton, MA 02301-5596. Fax: +1-508-580-0059. (R.W. McCarley)
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Ryvlin P, Mauguière F. L’imagerie fonctionnelle chez l’adulte. Rev Neurol (Paris) 2004. [DOI: 10.1016/s0035-3787(04)71190-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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40
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Grova C, Jannin P, Biraben A, Buvat I, Benali H, Bernard AM, Scarabin JM, Gibaud B. A methodology for generating normal and pathological brain perfusion SPECT images for evaluation of MRI/SPECT fusion methods: application in epilepsy. Phys Med Biol 2003; 48:4023-43. [PMID: 14727749 DOI: 10.1088/0031-9155/48/24/003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Quantitative evaluation of brain MRI/SPECT fusion methods for normal and in particular pathological datasets is difficult, due to the frequent lack of relevant ground truth. We propose a methodology to generate MRI and SPECT datasets dedicated to the evaluation of MRI/SPECT fusion methods and illustrate the method when dealing with ictal SPECT. The method consists in generating normal or pathological SPECT data perfectly aligned with a high-resolution 3D T1-weighted MRI using realistic Monte Carlo simulations that closely reproduce the response of a SPECT imaging system. Anatomical input data for the SPECT simulations are obtained from this 3D T1-weighted MRI, while functional input data result from an inter-individual analysis of anatomically standardized SPECT data. The method makes it possible to control the 'brain perfusion' function by proposing a theoretical model of brain perfusion from measurements performed on real SPECT images. Our method provides an absolute gold standard for assessing MRI/SPECT registration method accuracy since, by construction, the SPECT data are perfectly registered with the MRI data. The proposed methodology has been applied to create a theoretical model of normal brain perfusion and ictal brain perfusion characteristic of mesial temporal lobe epilepsy. To approach realistic and unbiased perfusion models, real SPECT data were corrected for uniform attenuation, scatter and partial volume effect. An anatomic standardization was used to account for anatomic variability between subjects. Realistic simulations of normal and ictal SPECT deduced from these perfusion models are presented. The comparison of real and simulated SPECT images showed relative differences in regional activity concentration of less than 20% in most anatomical structures, for both normal and ictal data, suggesting realistic models of perfusion distributions for evaluation purposes. Inter-hemispheric asymmetry coefficients measured on simulated data were found within the range of asymmetry coefficients measured on corresponding real data. The features of the proposed approach are compared with those of other methods previously described to obtain datasets appropriate for the assessment of fusion methods.
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Affiliation(s)
- C Grova
- Laboratoire IDM, Faculté de Médecine, Université de Rennes 1, Rennes, France.
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Aubert-Broche B, Grova C, Jannin P, Buvat I, Benali H, Gibaud B. Detection of inter-hemispheric asymmetries of brain perfusion in SPECT. Phys Med Biol 2003; 48:1505-17. [PMID: 12817934 DOI: 10.1088/0031-9155/48/11/302] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Technetium-99m HMPAO and technetium-99m ECD single photon emission computed tomography (SPECT) imaging is commonly used to highlight brain regions with altered perfusion. It is particularly useful in the investigation of intractable partial epilepsy. However, SPECT suffers from poor spatial resolution that makes interpretation difficult. In this context, we propose an unsupervised voxel neighbourhood based method to assist the detection of significant functional inter-hemispheric asymmetries in brain SPECT, using anatomical information from MRI. For each MRI voxel, the anatomically homologous voxel in the contralateral hemisphere is identified. Both homologous voxel coordinates are then mapped into the SPECT volume using SPECT-MRI registration. Neighbourhoods are then defined around each SPECT voxel and compared to obtain a volume of inter-hemispheric differences. A volume including only the statistically significant inter-hemispheric differences is deduced from this volume using a non-parametric approach. The method was validated using realistic analytical simulated SPECT data including known asymmetries (in size and amplitude) as ground truth (gold standard). Detection performance was assessed using an ROC (receiver operating characteristic) approach based on the measures of the overlap between known and detected asymmetries. Validation with computer-simulated data demonstrates the ability to detect asymmetric zones with relatively small extension and amplitude. The registration of these detected functional asymmetries on the MRI enables good anatomical localization to be achieved.
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Affiliation(s)
- B Aubert-Broche
- Laboratoire IDM, Faculté de Médecine, Université de Rennes 1, Rennes, France.
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Lee SK, Lee DS, Yeo JS, Lee JS, Kim YK, Jang MJ, Kim KK, Kim SK, Oh JB, Chung CK. FDG-PET images quantified by probabilistic atlas of brain and surgical prognosis of temporal lobe epilepsy. Epilepsia 2002; 43:1032-8. [PMID: 12199728 DOI: 10.1046/j.1528-1157.2002.29701.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE This study evaluated the relation between hypometabolism, diagnosed by fluorodeoxyglucose positron emission tomography (FDG-PET), and the surgical outcome of a large and homogeneous series of cases of mesial temporal lobe epilepsy (mTLE), by using a probabilistic atlas of the human brain (statistical probabilistic anatomical maps: SPAM). METHODS Ninety-five surgically proven intractable mTLE patients and 22 age-matched controls were spatially normalized to the average brain PET template of international consortium of brain mapping (ICBM). The diagnosis of mTLE was confirmed by the presence of hippocampal sclerosis on magnetic resonance imaging (MRI) and video-EEG monitoring. Counts from normalized PET images were multiplied by the probability from 98 volumes of interest (VOIs) of SPAM. Asymmetric indexes (AIs) reflecting the severity of hypometabolism were calculated by counts of selected 12 VOIs from SPAM images in both temporal lobes. Extent of hypometabolism was determined by the number of voxels showing decreased metabolism in each VOI segmented by SPAM. RESULTS Of the 95 patients studied, 76 (80%) were seizure free, and 19 (20%) had postoperative seizures for the > or =2-year follow-up period. No significant association between the severity of hypometabolism in each VOI of the temporal lobe and surgical outcome was identified (p > 0.05). The number of voxels showing decreased hypometabolism was not significantly different between the good- and poor-outcome groups (p > 0.05). CONCLUSIONS Our results demonstrated that focal severity and extent of hypometabolism quantified by a probabilistic atlas of brain were not related to the surgical outcome in mTLE patients who had hippocampal sclerosis on MRI. We should develop a more localized and specified anatomic map for mTLE for further results.
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Affiliation(s)
- Sang Kun Lee
- Departments of Neurology, Nuclear Medicine, and Neurosurgery, Seoul National University College of Medicine, Seoul, Korea.
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Sato C, Nemoto M, Tamura M. Reassessment of activity-related optical signals in somatosensory cortex by an algorithm with wavelength-dependent path length. THE JAPANESE JOURNAL OF PHYSIOLOGY 2002; 52:301-12. [PMID: 12230807 DOI: 10.2170/jjphysiol.52.301] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Incorporating the wavelength dependence of the scattering effect into a simple linear multicomponent analysis of intrinsic optical signals, we have reexamined the change in the hemoglobin (Hb) concentration and the origins of intrinsic signals in somatosensory cortex evoked with electrical stimulation of the hind limb (5 Hz, 2 s) of anesthetized rat. The concept of the analysis was to separate the effect of light scattering involved in the observed optical signals into two factors, light attenuation and modification of Hb absorption as a result of the wavelength dependence of the optical path length. This dependency was experimentally assessed with a tissue-simulating phantom whose absorption spectra were nearly identical to those of cerebral tissue through a thinned skull window in vivo. Using those phantom spectra, we carried out a curve fitting of the reflection spectra from the rat somatosensory cortex activated with an electrical stimulation of hind limb (5 Hz, 2 s). Oxygenated Hb slightly decreased at 0.5-1.5 s after an onset of the stimulus followed by an increase, which peaked at 4 s. Deoxygenated Hb increased at 1.0-1.5 s followed by a large late decrease. We again confirmed an early increase in the concentration of deoxygenated Hb in the rat somatosensory cortex after stimulation of the hind limb.
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Affiliation(s)
- Chie Sato
- Biophysics Laboratory, Research Institute for Electronic Science, Hokkaido University, Sapporo, 060-0812 Japan.
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Kim SK, Lee DS, Lee SK, Kim YK, Kang KW, Chung CK, Chung JK, Lee MC. Diagnostic performance of [18F]FDG-PET and ictal [99mTc]-HMPAO SPECT in occipital lobe epilepsy. Epilepsia 2001; 42:1531-40. [PMID: 11879363 DOI: 10.1046/j.1528-1157.2001.21901.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE We investigated whether interictal F-18 fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) or ictal [99mTc]-HMPAO single-photon emission computed tomography (SPECT) was useful to find epileptogenic zones in occipital lobe epilepsy (OLE). METHODS We reviewed visually and quantified patterns of hypometabolism in interictal [18F]FDG-PET and those of hyperperfusion in ictal SPECT in 17 OLE patients (27 plus minus 6.8 years old; M/F, 10/7; injection time, 30 plus minus 17 s). OLE was diagnosed based on invasive electroencephalography, surgery, and postsurgical outcome (Engel class I in all at an average of 26 months after surgery). RESULTS Epileptogenic zones were correctly localized in nine (60%) of 15 patients by interictal [18F]FDG-PET, and asymmetric indices corroborated visual diagnosis. Epileptogenic hemispheres were correctly lateralized in 14 (93%) of 15 patients on [18F]FDG-PET. Epileptogenic hemispheres were correctly lateralized in 13 (76%) of 17 patients using ictal SPECT, but localization was possible in only five (29%) patients. Interictal [18F]FDG-PET was helpful in two of the patients who showed no abnormality on magnetic resonance imaging (MRI) and no possible localization with ictal SPECT. CONCLUSIONS In OLE, ictal SPECT was helpful in lateralization, but less helpful in localization. Interictal [18F]FDG-PET was helpful in localization or lateralization of epileptogenic zones, even in patients with ambiguous MRI or ictal SPECT findings.
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Affiliation(s)
- S K Kim
- Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Korea
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Lee DS, Lee JS, Kang KW, Jang MJ, Lee SK, Chung JK, Lee MC. Disparity of perfusion and glucose metabolism of epileptogenic zones in temporal lobe epilepsy demonstrated by SPM/SPAM analysis on 15O water PET, [18F]FDG-PET, and [99mTc]-HMPAO SPECT. Epilepsia 2001; 42:1515-22. [PMID: 11879361 DOI: 10.1046/j.1528-1157.2001.21801.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To elucidate uncoupling of perfusion and metabolism and its significance in epilepsy, 15O water and 18F fluorodeoxyglucose (FDG) positron emission tomography (PET) and Tc-99m hexamethyl-propyleneamine-oxime (HMPAO) single-photon emission computed tomography (SPECT) were examined by SPM (statistical parametric mapping) and quantitation by using SPAM (statistical probabilistic anatomic map). METHODS [15O]water and [18F]FDG-PET, and [99mTc]-HMPAO SPECT were performed in 25 patients (SPECT in 17 of 25) with medial temporal lobe epilepsy. For volume of interest (VOI) count analysis, the normalized counts using VOI based on SPAM templates of PET and SPECT were compared with those of the normal controls. Perfusion or metabolism was found abnormal if the Z score was >2 for each VOI. For SPM analysis, the differences between each patient's image and a group of normal control images (t statistic for p < 0.01) on a voxel-by-voxel basis were examined to find significant decreases in perfusion or metabolism. RESULTS With SPAM VOI count analysis, areas of hypoperfusion were found in 13 patients in the epileptogenic temporal lobes by [15O]water PET and areas of hypometabolism in 21 patients by [18F]FDG-PET. With voxel-based SPM analysis, the epileptogenic zones were localized in 15 by [15O]water PET and in 23 patients by [18F]FDG-PET. The localization by [15O]water PET was concordant with that of [18F]FDG-PET. The areas of hypoperfusion on [15O]water PET were absent or smaller than the areas of hypometabolism on [18F]FDG-PET. Interictal [99mTc]-HMPAO SPECT revealed the hypoperfused zones in seven of 17 patients on visual assessment. CONCLUSIONS SPAM VOI count and SPM analysis of [15O]water and [18F]FDG-PET and [99mTc]-HMPAO SPECT revealed that in the same patients, the areas of hypoperfusion were concordant with but smaller than the areas of hypometabolism. Discordance of perfusion and metabolic abnormalities represents an uncoupling of perfusion and metabolism in the epileptogenic zones, and this might explain the lower diagnostic accuracy of perfusion imaging in temporal lobe epilepsy.
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Affiliation(s)
- D S Lee
- Seoul National University Medical Research Center, Institute of Radiation Medicine, Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea
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Hilgetag CC, Théoret H, Pascual-Leone A. Enhanced visual spatial attention ipsilateral to rTMS-induced 'virtual lesions' of human parietal cortex. Nat Neurosci 2001; 4:953-7. [PMID: 11528429 DOI: 10.1038/nn0901-953] [Citation(s) in RCA: 424] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The breakdown of attentional mechanisms after brain damage can have drastic behavioral consequences, as in patients suffering from spatial neglect. While much research has concentrated on impaired attention to targets contralateral to sites of brain damage, here we report the ipsilateral enhancement of visual attention after repetitive transcranial magnetic stimulation (rTMS) of parietal cortex at parameters known to reduce cortical excitability. Normal healthy subjects received rTMS (1 Hz, 10 mins) over right or left parietal cortex. Subsequently, detection of visual stimuli contralateral to the stimulated hemisphere was consistently impaired when stimuli were also present in the opposite hemifield, mirroring the extinction phenomenon commonly observed in neglect patients. Additionally, subjects' attention to ipsilateral targets improved significantly over normal levels. These results underline the potential of focal brain dysfunction to produce behavioral improvement and give experimental support to models of interhemispheric competition in the distributed brain network for spatial attention.
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Affiliation(s)
- C C Hilgetag
- Boston University School of Medicine, Department of Anatomy and Neurobiology, 700 Albany Street W746, Boston, Massachusetts 02118, USA.
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