• 제목/요약/키워드: MRI(magnetic resonance imaging)

검색결과 2,040건 처리시간 0.026초

Advanced neuroimaging techniques for evaluating pediatric epilepsy

  • Lee, Yun Jeong
    • Clinical and Experimental Pediatrics
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    • 제63권3호
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    • pp.88-95
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    • 2020
  • Accurate localization of the seizure onset zone is important for better seizure outcomes and preventing deficits following epilepsy surgery. Recent advances in neuroimaging techniques have increased our understanding of the underlying etiology and improved our ability to noninvasively identify the seizure onset zone. Using epilepsy-specific magnetic resonance imaging (MRI) protocols, structural MRI allows better detection of the seizure onset zone, particularly when it is interpreted by experienced neuroradiologists. Ultra-high-field imaging and postprocessing analysis with automated machine learning algorithms can detect subtle structural abnormalities in MRI-negative patients. Tractography derived from diffusion tensor imaging can delineate white matter connections associated with epilepsy or eloquent function, thus, preventing deficits after epilepsy surgery. Arterial spin-labeling perfusion MRI, simultaneous electroencephalography (EEG)-functional MRI (fMRI), and magnetoencephalography (MEG) are noinvasive imaging modalities that can be used to localize the epileptogenic foci and assist in planning epilepsy surgery with positron emission tomography, ictal single-photon emission computed tomography, and intracranial EEG monitoring. MEG and fMRI can localize and lateralize the area of the cortex that is essential for language, motor, and memory function and identify its relationship with planned surgical resection sites to reduce the risk of neurological impairments. These advanced structural and functional imaging modalities can be combined with postprocessing methods to better understand the epileptic network and obtain valuable clinical information for predicting long-term outcomes in pediatric epilepsy.

Prediction of Axillary Lymph Node Metastasis in Early Breast Cancer Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging and Diffusion-Weighted Imaging

  • Jeong, Eun Ha;Choi, Eun Jung;Choi, Hyemi;Park, Eun Hae;Song, Ji Soo
    • Investigative Magnetic Resonance Imaging
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    • 제23권2호
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    • pp.125-135
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    • 2019
  • Purpose: The purpose of this study was to evaluate dynamic contrast-enhanced breast magnetic resonance imaging (DCE-MRI), and diffusion-weighted imaging (DWI) variables, for axillary lymph node (ALN) metastasis in the early stage of breast cancer. Materials and Methods: January 2011-April 2015, 787 patients with early stage of breast cancer were retrospectively reviewed. Only cases of invasive ductal carcinoma, were included in the patient population. Among them, 240 patients who underwent 3.0-T DCE-MRI, including DWI with b value 0 and $800s/mm^2$ were enrolled. MRI variables (adjacent vessel sign, whole-breast vascularity, initial enhancement pattern, quantitative kinetic parameters, signal enhancement ratio (SER), tumor apparent diffusion coefficient (ADC), peritumoral ADC, and peritumor-tumor ADC ratio) clinico-pathologic variables (age, T stage, multifocality, extensive intraductal carcinoma component (EIC), estrogen receptor, progesterone receptor, HER-2 status, Ki-67, molecular subtype, histologic grade, and nuclear grade) were compared between patients with axillary lymph node metastasis and those with no lymph node metastasis. Multivariate regression analysis was performed, to determine independent variables associated with ALN metastasis, and the area under the receiver operating characteristic curve (AUC), for predicting ALN metastasis was analyzed, for those variables. Results: On breast MRI, moderate or prominent ipsilateral whole-breast vascularity (moderate, odds ratio [OR] 3.45, 95% confidence interval [CI] 1.28-9.51 vs. prominent, OR = 15.59, 95% CI 2.52-96.46), SER (OR = 1.68, 95% CI 1.09-2.59), and peritumor-tumor ADC ratio (OR = 6.77, 95% CI 2.41-18.99), were independently associated with ALN metastasis. Among clinico-pathologic variables, HER-2 positivity was independently associated, with ALN metastasis (OR = 23.71, 95% CI 10.50-53.54). The AUC for combining selected MRI variables and clinico-pathologic variables, was higher than that of clinico-pathologic variables (P < 0.05). Conclusion: SER, moderate or prominent increased whole breast vascularity, and peritumor-tumor ADC ratio on breast MRI, are valuable in predicting ALN metastasis, in patients with early stage of breast cancer.

Hyperperfusion in DWI Abnormality in a Patient with Acute Symptomatic Hypoglycemic Encephalopathy

  • Park, Ji Kang
    • Investigative Magnetic Resonance Imaging
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    • 제21권2호
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    • pp.106-108
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    • 2017
  • The perfusion change in acute symptomatic hypoglycemic encephalopathy (ASHE) is not well known. We present the perfusion-weighted imaging of a patient with ASHE. The area of diffusion-weighted imaging abnormalities and adjacent normal-appearing white matter showed increased cerebral blood volume and flow, and shortening of time-to-peak.

Magnetic Resonance Imaging of Idiopathic Herniation of the Lingual Gyrus: a Case Report

  • Seok, Hee Young;Lee, Dong Hoon
    • Investigative Magnetic Resonance Imaging
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    • 제21권3호
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    • pp.195-198
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    • 2017
  • Idiopathic brain herniation is a rare condition. We believe that this is the first reported case of idiopathic herniation of the lingual gyrus. The case involves a 57-year-old woman presenting with frontal headache without overt visual symptoms. Magnetic resonance imaging (MRI) revealed an idiopathic herniation of the lingual gyrus of the occipital lobe extending into the quadrigeminal cistern. No other adjacent intracranial abnormalities were observed. Although some conditions may be considered in the differential diagnosis, accurate diagnosis of idiopathic brain herniation in medical practice can prevent unnecessary additional imaging procedures and invasive open biopsy in patients with typical imaging findings.

Bone Involvement of Diffuse Large B Cell Lymphoma (DLBCL) Showing Unusual Manifestations Mimicking Chronic Osteomyelitis in a 58-Year-Old Man: Case Report and Clinical Application of Diffusion Weighted Magnetic Resonance Imaging

  • Lee, Kyung Ryeol;Maeng, Young Hee
    • Investigative Magnetic Resonance Imaging
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    • 제23권3호
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    • pp.270-275
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    • 2019
  • This study presents a case of diffuse large B cell lymphoma (DLBCL) in a 58-year-old man showing unusual manifestations mimicking chronic osteomyelitis. In this case review, we describe the imaging findings of DLBCL which mimics chronic osteomyelitis and review existing reports regarding the differential diagnosis of bone involvement of lymphoma and osteomyelitis through imaging and laboratory findings and diffusion-weighted magnetic resonance imaging (DWI) such as the advanced MRI sequence.

Retrospective Review of Magnetic Resonance Imaging of the Lumbosacral Spine: Are We Overinvestigating?

  • Khanduja, Suchit;Loomba, Vivek;Salama-Hannah, Joseph;Upadhyay, Aman;Khanduja, Neha;Chauhan, Gaurav
    • Neurospine
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    • 제15권4호
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    • pp.383-387
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    • 2018
  • Objective: Lower back pain (LBP) is a worldwide health problem, and magnetic resonance imaging (MRI) is a common modality used to aid in its diagnosis. Although specific guidelines for assessing the necessity of MRI usage exist, the use of MRI as the initial imaging method for LBP seems to be more common than necessary in general practice. Methods: We conducted a retrospective chart review of 313 patients who had undergone MRI of the lumbosacral spine during 2014-2015. We recorded and compared various factors, including age, sex, body mass index, current smoking status, race, symptoms, MRI findings, and progression to surgery within the next year. All rates were compared according to whether the MRI results showed radiographically significant findings (MRI-positive) or not (MRI-negative) using the chi-square or Fisher exact tests (if the expected cell count was <5). All analyses were performed using SAS version 9.4. Results: There were no statistically significant differences in the rates of each symptom between the MRI-positive and MRI-negative groups, which accounted for 58.5% (183 of 313) and 41.5% (130 of 313) of the MRIs, respectively. The difference in the rate of surgery in the next year (18% among MRI-positive patients and 8.5% among MRI-negative patients) was found to be statistically significant (p<0.05). Conclusion: Based on our findings, 41.5% of patients underwent lumbar MRI unnecessarily and 81% of patients with positive MRIs did not have surgery within the next year. Further physician training is needed to avoid unnecessary investigations and expenditures.

Positron emission tomography and magnetic resonance imaging

  • Yim, Min Su;Ryu, Eun Kyoung
    • 대한방사성의약품학회지
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    • 제2권1호
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    • pp.3-8
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    • 2016
  • Molecular imaging technologies have been used to provide a new pathway for therapies and diagnosis of human disease. Especially, imaging probes have been much development in the molecular imaging field. Combining imaging probes for positron emission tomography (PET) and magnetic resonance imaging (MRI) have suggested the potential of multiple methods in living body. This review discusses the cancer or lymph node-targeting probes that are suitable for PET/MRI based diagnosis.

Multiparametric Functional Magnetic Resonance Imaging for Evaluating Renal Allograft Injury

  • Yuan Meng Yu;Qian Qian Ni;Zhen Jane Wang;Meng Lin Chen;Long Jiang Zhang
    • Korean Journal of Radiology
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    • 제20권6호
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    • pp.894-908
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    • 2019
  • Kidney transplantation is the treatment of choice for patients with end-stage renal disease, as it extends survival and increases quality of life in these patients. However, chronic allograft injury continues to be a major problem, and leads to eventual graft loss. Early detection of allograft injury is essential for guiding appropriate intervention to delay or prevent irreversible damage. Several advanced MRI techniques can offer some important information regarding functional changes such as perfusion, diffusion, structural complexity, as well as oxygenation and fibrosis. This review highlights the potential of multiparametric MRI for noninvasive and comprehensive assessment of renal allograft injury.

Magnetic Resonance Imaging (MRI) of a Hypertrophy of Cartilage and Simultaneous Regeneration of a Damaged Meniscus after Autologous Bone Marrow Aspirates Concentrate (BMAC) Transplantation: a Case Report and Literature Review

  • Bae, Sung Hwan;Kim, Hyun-joo;Oh, Eunsun;Hwang, Jiyoung;Hong, Seong Sook;Hwang, Jung Hwa
    • Investigative Magnetic Resonance Imaging
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    • 제21권3호
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    • pp.187-191
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    • 2017
  • Bone marrow aspirates concentrate (BMAC) transplantation is a well-known technique for cartilage regeneration with good clinical outcomes for symptoms in patients with osteoarthritis (OA). Magnetic resonance imaging (MRI) has an important role in evaluating the degree of cartilage repair in cartilage regeneration therapy instead of a second assessment via an arthroscopy. We experienced a case of hypertrophic regeneration of the cartilage and a presumed simultaneous regeneration of the posterior horn of the lateral meniscus after BMAC transplantation for a cartilage defect at the lateral tibial and femoral condyle. This report provides the details of a case of an unusual treatment response after a BMAC transplant. This report is the first of its kind to demonstrate a MR image that displays the simultaneous regeneration of the cartilage and meniscus with a differentiation ability of the mesenchymal stem cell to the desired cell lineage.

자기공명영상에서 ACR 팬텀을 이용한 해상력 특성 평가 (Evaluation of the Resolution Characteristics by Using American College of Radiology Phantom for Magnetic Resonance Imaging)

  • 민정환;정회원;한지현;이시내;김민지;김승철
    • 대한방사선기술학회지:방사선기술과학
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    • 제45권1호
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    • pp.11-17
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    • 2022
  • This study was purpose to quantitative assessment of the resolution characteristics by using American college of radiology(ACR) phantom for magnetic resonance imaging (MRI). The MRI equipment was used (Achiva 3.0T MRI, Philips system, Netherlands) and the head/neck matrix shim SENSE head coil were 32 channels(elements) receive MR coil. And the MRI equipment was used (Discovery MR 750, 3.0T MRI, GE medical system, America) and the head/neck matrix shim MC 3003G-32R 32-CH head coil were receive MR coil. As for the modulation transfer function(MTF) comparison result by using ACR magnetic resonance imaging phantom, the MTF value of the ACR standard T2 image in GE equipment is 0.199 when the frequency is 1.0 mm-1 and the MTF value of the hospital T2 image in Philips equipment is 0.528. It was used efficiently by using a general sequence more than the standard sequence method using the ACR phantom. In addition it is significant that the quantitative quality assurance evaluation method for resolution characteristics was applied mutatis mutandis, and the result values of the physical image characteristics of the 3.0T MRI device were presented.