Brain Topological Correlates of Motor Performance Changes After Repetitive Transcranial Magnetic Stimulation

Park, Chang-hyun,Chang, Won Hyuk,Yoo, Woo-Kyoung,Shin, Yong-Il,Kim, Sung Tae,Kim, Yun-Hee Mary Ann Liebert 2014 Brain connectivity Vol.4 No.4

<P>Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain networks and specifically the association of brain topological changes with motor performance changes. In a sham-controlled parallel group experimental design, real or sham rTMS was administered to each of the 15 healthy subjects without prior motor-related dysfunctions, over the right M1 at a high frequency of 10 Hz. Before and after the intervention, fMRI data were acquired during a sequential finger motor task using the left, nondominant hand. Changes in the topology of brain networks were assessed in terms of global and local efficiency, which measures the efficiency in transporting information at global and local scales, respectively, provided by graph-theoretical analysis. Greater motor performance changes toward improvements after real rTMS were shown in individuals who exhibited more increases in global efficiency and more decreases in local efficiency. The enhancement of motor performance after rTMS is supposed to be associated with brain topological changes, such that global information exchange is facilitated, while local information exchange is restricted.</P>

Long second toe: its nail and skin changes

( Geun-hwi Park ),( Woo-il Kim ),( Min-young Yang ),( Won-ku Lee ),( Tae-wook Kim ),( Sung-min Park ),( Hyun-joo Lee ),( Gun-wook Kim ),( Hoon-soo Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Nail can be affected by trauma, infection, and systematic disorders. In particular, the toe nails are exposed to the repeated and cumulative minor traumas, which usually result in thickened, splitted, and discolorated nails. Considering these, it can be inferred that the long second toe can be related to various nail and skin changes by repeated minor traumas such as friction in shoes, but the study or report on this topic hasn’t been done yet. Objectives: The purpose of this study was to introduce various nail and skin changes on long second toe. Methods: We analyzed the kinds of nail/skin changes of 50 patients with long second toe, enrolled at Pusan National University Hospitals (Busan and Yangsan) from 2013 to 2018. Results: There was no significant difference in the incidence of left and right toe and toenail, and 7 (14%) patients presented bilateral distribution. The most common nail change on long second toe was melanonychia (23, 46%), followed by subungual hematoma (15, 30%), onycholysis (2, 4%), subungual hyperkeratosis (2, 4%), onychomadesis (1, 2%), and retronychia (1, 2%). The most common skin change was corn (9, 18%), followed by paronychia (2, 4%). Twenty (20/50, 40%) patients also had other toe or toenail changes. Among them, the most common site was big toe/nail (13, 62%), and the most common change was subungual hematoma (8, 42%). Conclusion: Through this study, the dermatologists can recognize and diagnose the nail and skin changes of long second toe.

조기 천장골염의 자기공명영상 소견

김태환 ( Tae Hwan Kim ),전재범 ( Jae Bum Jun ),심승철 ( Seung Cheol Shim ),장대국 ( Dae Kook Chang ),고회관 ( Hee Kwan Koh ),정성수 ( Sung Soo Jung ),이인홍 ( In Hong Lee ),배상철 ( Sang Cheol Bae ),유대현 ( Dae Hyun Yoo ),전의용 대한류마티스학회 1998 대한류마티스학회지 Vol.5 No.2

목적: 천장골염의 유무가 척추 관절염의 진단에 중요한데 단순 골반 검사에서 변화가 없는 환자를 대상으로 MRI를 이용하여 천장골염의 조기변화 소견 및 MRI방법에 따른 장점을 비교하고자 하였다. 대상 및 방법: 단순 골반 검사에서 천장골염 유무가 확실하게 구분되지 않은 혈청 음성 척추 관절염 환자 26명을 대상으로 MRI를 시행하고 염증의 주침범위치를 천측과 장측, 관절의 상하로 구분하고, MRI방법에 따른 변화를 비교하였다. 결과: 모든 예에서 조영 증강되는 판누스를 관찰할 수 있었고, Grade I 이하에서는 장골측과 관절하부, 인대성 관절보다 활막성 관절을 더 많이 침범하였다. Grade II 이상에서도 장골측과 관절 하부에 더 많았으나 인대성 관절을 Grade I이하에서보다 더 많이 침범하였다. 관절 주변 지방 침착역시 장골측과 관절 하부에 더 주로 침범하였고 Grade II 이상에서 약간 더 많았다. 관절 주변 골염은 Grade 0에서는 없었고, Grade I에서는 주로 장골측과 관절 하부에서 92%가 양성이었고, Grade II에서는 93%에서, Grade III에서는 64%에서 양성으로, 장골측을 주로 침범하였으나 관절 상하부의 구분은 없었다. 인대성 천장골 관절은 Grade I 이하에서 38%, II 이상에서는 94%에서 침범하였다. 관절 주변 골염과 지방 침착, 그리고 판누스의 관찰에는 MPGR보다 스핀에코 영상이 좋았고, 관절면의 불규칙성 또는 관절강의 확대와 관절 강직여부의 관찰에는 스핀에코에 비해 MPGR 영상이 좋았고, 연골하 경화는 비슷하였다. 천장골염의 정도와 ESR, CRP와의 연관성은 없었다. 걸론: 천장골 관절에서 염증의 시작은 주로 장골 측과 관절의 하부에서 먼저 시작되고, 관절이 진행될수록 장골측에서 천골측까지로 범위가 확대 되었다. MRI방법에 의한 차이로 초기단계에는 스핀에코 영상이 관절염을 확인하는데 도움이 되고 관절면이 불규칙하게 되고 경화가 되어 병이 진행된 상태에서는 MPGR영상이 진단에 더 도움이 되었다. 염증성 배부 동통이 있는 경우 단순 골반 검사에서 이상이 없는 환자인 경우에도 MRI 검사를 시행하여 천장골염의 유무를 확인하는 것이 중요하다. Objective: The early detection of sacroiliitis on X-ray is important to diagnose spondyloarthropathy(SpA). The conventional radiography, bone scan, and computer tomogram have the problems of sensitivity, specificity, and side effects. We examined sacroiliitis using MR imaging in patients who had inflammatory back pain, but no definite changes in conventional radiogrphy. Other radiologic techniques were compared in detection of early sacroillitis. Methods: Twenty six patients with SpA were examined. The MRI findings of both sacroiliac joints were evaluated in every patients, such as pannus, periarticular osteitis and fat accumulation, subchondral sclerosis, and joint space changes(irregularity, ankylosis). Also we analyzed the changes of sacroiliac joints in sacroiliitis. Results: The predominant sites of involvement were upper aspect and iliac surface of sacroiliac joint in subchondral sclerosis, lower and iliac in pannus, periarticular fat accumulation, and iliac in periarticular osteitis. The MPGR images were superior to spin echo images in evaluation of joint space changes(irregularity, and ankylosis). Conclusions: Sacroiliitis is initiated in iliac side and lower portion of sacroiliac joints. MRI can detect early changes of sacroiliitis in patients with no conventional radiographic changes. MRI seems to be needed in patients with inflammatory back pain.

Evaluation of a Dual-Cooled Annular Fuel Heat Split and Temperature Distribution

YANG, Yong Sik,SHIN, Chang Hwan,CHUN, Tae Hyun,SONG, Kun Woo Atomic Energy Society of Japan 2009 Journal of nuclear science and technology Vol.46 No.8

<P>The heat flux and fuel temperature of an annular fuel rod was analyzed using a newly developed program, DUO_THERM. The dual-cooled annular fuel rod has both inner and outer coolant channels. The heat fluxes to inner and outer claddings can change during irradiation because of the variation in the gap conductances of the inner and outer sides. The heat flux is a very important design factor affecting fuel integrity and safety. However, in an annular fuel design, the prediction of heat flux is very complicated because it is closely connected with size changes of two gaps, which are different from each other during irradiation. A burnup increase and power change can cause pellet and cladding radial deformation and eventually change the gap width. Because an annular fuel has two gaps at both sides and their heat resistances are very large, an imbalance of the gap width can lead to heat flux asymmetry. Therefore, a pellet and cladding dimensional change including densification, swelling, creep, and thermal expansion must be considered in the calculation of heat flux and temperature. By using the DUO_THERM program, the changes in heat flux and temperature during an operation were evaluated with respect to a reference design of an annular fuel. The results of the evaluation showed that the heat flux of an annular fuel was greatly affected by the inner and outer gap conductance changes. The heat flux of the inner cladding was maximum at zero burnup, but that of the outer cladding was maximum at the burnup of the outer gap closing. In addition, the maximum fuel temperature location was changed by gap conductance asymmetry.</P>

흉부 CT 검사에서 Scan Direction이 Automatic Exposure Control을 적용한 선량에 미치는 영향에 관한 연구

남태현(Tae Hyun Nam),정용환(Yong Hwan Jeong),김주현(Joo Hyun Kim),권순안(Soon Ahn Gwon),대창민(Chang Min Dae),김성룡(Sung Ryong Kim),민관홍(Kwan Hong Min) 대한CT영상기술학회 2012 대한CT영상기술학회지 Vol.14 No.2

목적 적정한 영상의 질과 합리적인 선량위해 이용되고 있는 Automatic Exposure Control에 대한 다양한 연구가 진행되고 있는 가운데 scan direction의 영향에 대한 연구는 미비한 실정이기에, 본 논문에서는 AE를 적용한 흉부 CT검사에서 scan direction이 선량에 미치는 영향에 대해 알아보고자 하였다. 대상 및 방법 Somatom Definition Flash(Siemens Healthcare, 이하 S사), Aquilion 64(Toshiba Medical System, 이하 T사), LightSpeed VCT(General Electric Medical System, 이하 G사), Brilliance iCT(Philips healthcare, 이하 p시)와 인체 등가물질의 whole body phantom을 이용하였다. Phantom position은 supine, feet first로 위치시키고, SPR parameter 중 관전압을 120, 100, 80 kV로 각각 group 1, group 2, group 3으로 분류 후, cranio-caudal scan direction, caudo-cranial scan direction으로 각 5회 반복 scan 하고 선량 비교는 장비에서 제공하는 CTDIvol 값의 평균값을 구하여 scan direction에 따른 변화를 각 제조사별로 비교하였다. 결과 S사의 평균 CTDIvol 값을 비교해 본 결과 cranio-caudal scan direction에 대한 caudo-cranial scan direction의 증감률은 group 1에서 -4.22%, group 2에서 -5.27%, group 3에서 -4.50%로 나타났고, T사의 증감률은 group 1에서 -9.41%, group 2에서 -8.20%, group 3에서 -9.31%로 측정되었다. G사의 증감률은 group 1에서 -1.65%, group 2에서 -3.41%, group 3에서 -3.23%로 나타났으며. P사의 증감률은 group 1에서 +1.21%, group 2에서 -1.58% group 3에서 -2.41%로 나타났다. 결론 AEC를 적용한 흉부 CT검사에서 scan direction이 변화함에 따라 환자에 적용되는 선량에 차이가 발생하는 것으로 나타났다. 이러한 결과를 통해 기존에 AEC에 영향을 주는 것으로 알려진 요인 외에 scan direction 또한 영향을 미치는 것을 알 수 있었다. 따라서, 제조사별 AEC에 대한 심도있는 이해를 바탕으로 그 영향인자에 대한 추가적인 연구가 필요할 것이며, 이러한 연구들을 통해 검사부위에 맞는 최적화된 기법을 적용한다면 더욱 합리적인 선량감소를 달성할 수 있을 것으로 사료된다. I. Purpose There are many studies about automatic exposure control system. However, there is not enough study between scan direction and ABC. The purpose of this study was to compare radiation exposure dose in chest CT depending on scan direction. II. Meterial and Methods Somatom Definition Flash(Siemens Healthcare), Aquilion 64(Toshiba Medical system), LightSpeed VCT(General Electric Medical System), Brilliance iCT(Philips healthcare) and whole body phantom(KUPBU - 50 Kyoto kagaku Co.Ltd) are used in this study, Phantom position was supine, feet first. Study was devided into 3 groups depending on scan projection radiography tube voltage: group 1(120kV), group 2(100 kV), group 3(80 kV). Average CTDIvol values are compared between cranio-caudal scan direction and caudo-cranial scan direction in each group. III. Result The CTDIvol between cranio-caudal scan direction and caudo-cranial scan direction is changed. Siemens result is -4.22% in group 1, -5.27% in group 2, -4.50% in group 3. Toshiba result is -9.41% in group 1, -8.20% in group 2, -9.31% in group 3. GE result is -1.65% in group 1, -3.41% in group 2, -3.23% in group 3. Philips result is +1.21% in group 1, -1.58% in group 2, -2.41% in group 3. IV. Conclusions Radiation exposure dose was changed between cranio-caudal scan direction and caudo-cranial scan direction in Chest CT with ABC. Therefore, scan direction can affect to AEC. We should consider about many factors of AEC and create suitable protocol for each body part in order to reduce radiation dose.

다국소 망막전위도를 통한 특발성 망막전막제거술 전후의 황반 기능 평가

윤창기(Chang Ki Yoon),김태훈(Tae Hoon Kim),김현웅(Hyun Woong Kim) 대한검안학회 2016 Annals of optometry and contact lens Vol.15 No.1

Purpose: To assess macular function after vitrectomy and membrane removal in eyes with idiopathic epiretinal membrane by means of multifocal electroretinogram (mfERG). Methods: Visual acuity, macular thickness measured by optical coherence tomography, and mfERG recordings were achieved for 14 eyes of 14 patients who having idiopathic epiretinal membrane. All exams were performed before epiretinal membrane surgery and 1, 3, and 6 months after surgery. Results: Amplitude of mfERG were 139.18 ± 73.63 nV/deg2, 114.25 ± 29.16 nV/deg2 and 134.66 ± 69.64 nV/deg2 at before surgery, after 1 month and 3 months, respectively. Implicit time were 75.23 ± 31.34 nV/deg2, 66.20 ± 25.04 nV/deg2 and 74.79 ± 15.47 nV/deg2 at before surgery, after 1 month and 3 months, respectively. There were no significant changes in amplitude and implicit time measured by mfERG before and after the surgery (p>0.05). There were no significant correlations between the changes of amplitude and implicit time and visual acuity and macular thickness change. Conclusions: Changes in mfERG recordings were not concluded to be useful for predicting clinical prognosis after epiretinal membrane surgery in this study.

Age-Associated Changes in the Vascular Renin-Angiotensin System in Mice

Yoon, Hye Eun,Kim, Eun Nim,Kim, Min Young,Lim, Ji Hee,Jang, In-Ae,Ban, Tae Hyun,Shin, Seok Joon,Park, Cheol Whee,Chang, Yoon Sik,Choi, Bum Soon Hindawi Publishing Corporation 2016 Oxidative medicine and cellular longevity Vol.2016 No.-

<P><I>Background</I>. This study evaluated whether the change in the renin-angiotensin system (RAS) is associated with arterial aging in mice.<I> Methods</I>. Histologic changes and expressions of transforming growth factor-<I>β</I> (TGF-<I>β</I>), collagen IV,<I> fibronectin</I>, angiotensin II (Ang II), angiotensin-converting enzyme (ACE), angiotensin-converting enzyme 2 (ACE2), angiotensin II type 1 receptor (AT1R), angiotensin II type 2 receptor (AT2R), prorenin receptor (PRR), Mas receptor (MasR), endothelial nitric oxide synthase (eNOS), NADPH oxidase 2 and oxidase 4 (Nox2 and Nox4), 8-hydroxy-2′-deoxyguanosine (8-OHdG),<I> 3-nitrotyrosine</I>, and superoxide dismutase 1 and dismutase 2 (SOD1 and SOD2) were measured in the thoracic aortas from 2-month-old, 12-month-old, and 24-month-old C57/BL6 mice.<I> Results</I>. Twenty-four-month-old mice showed significantly increased aortic media thickness and expressions of TGF-<I>β</I>, collagen IV, and fibronectin, compared to 2-month-old and 12-month-old mice. The expressions of PRR, ACE, and Ang II, and AT1R-positive area significantly increased, whereas expressions of ACE2 and MasR and AT2R-positive area decreased with age. The expressions of phosphorylated serine<SUP>1177</SUP>-eNOS, SOD1, and SOD2 decreased, and the 8-OHdG-positive area and the 3-nitrotyrosine-positive area increased with age. The expression of Nox2 significantly increased with age, but that of Nox4 did not change.<I> Conclusions</I>. The enhanced PRR-ACE-Ang II-AT1R axis and reduced ACE2-MasR axis were associated with arterial aging in mice. </P>

상피성 암세포주에 대한 녹차 Catechin의 효과

박정현(Jeong Hyun Park),김대중(Dae Joong Kim),한장희(Jang Hee Hahn),김홍태(Hong Tae Kim),정용욱(Yong Wook Jung),성훈기(Hoon Ki Sung),김주영(Joo Young Kim),송인환(In Hwan Song),성언기(Eon Gi Sung),이융창(Yung Chang Lee) 대한해부학회 2001 Anatomy & Cell Biology Vol.34 No.5

Catechin은 녹차에서 추출되는 폴리페놀의 주요성분으로 고혈압 및 동맥경화의 예방효과, 당뇨억제효과, 항산화작용, 항암작용 등에 직접 관여하는 물질이다. 본 연구에서는 태평양에서 제공받은 녹차 catechin을 이용하여 상피성 암세포주인 A549 (폐암)와 EATC (복수암)세포에 투여한 후 처리농도와 시간에 따른 변화를 비교, 관찰함으로써 녹차의 효과와 작용기전을 밝혀내는데 목적이 있었다. 본실험은 A549 세포와 EATC 세포를 배양한 후 녹차 catechin을 1, 10, 100, 500 μg/ml의 농도로 48시간 동안 처리하였고, 광학현미경, 공초점현미경, 전자현미경 등을 이용하여 세포의 구조적 변화를 확인하였으며 MTT분석, 전기영동, 유세포분석기 등을 사용하여 세포 손상정도를 파악하였다. A549 세포에서는 catechin 1 μg/ml와 10 μg/ml 농도에서는 대조군에 비하여 큰 변화를 관찰할 수 없었다. 100 μg/ml catechin을 처리하였을 때 세포내의 검은 과립들의 수가 증가하였고 층판소체의 손상이 나타났다. 세포주기의 장애가 나타나 DNA 합성전기에 있는 세포들의 수가 급격히 증가하였다. 500 μg/ml 농도에서는 층판소체와 사립체의 파괴가 심하게 나타났으며 세포생존율이 감소하였고 세포주기의 장애도 관찰되었다. EATC 세포에서는 catechin의 농도가 A549 세포의 경우보다 낮은 농도에서도 세포증식 억제 및 세포손상 효과가 나타났다. 10 μg/ml 농도에서도 세포의 위축과 생존율의 감소가 일어났으며 전기영동상에 괴사되는 세포들이 파악되었다. 100μg/ml catechin을 처리하였을 때 자연사의 형태학적 관찰, 전기영동, 유세포분석 등에서 자연사 과정에 있는 세포들이 많이 나타났다. 결과적으로 녹차 catechin을 배양한 상피성 암세포에 투여함으로서 세포의 생존율과 증식이 억제되었고 그 과정에서 괴사, 자연사, 세포주기의 장애 등이 관여하는 것으로 생각된다. 그러나 일련의 세포손상과정을 유도하는 데 있어 세포의 종류, 처리 시간, 농도에 따라 다소 차이가 있음을 확인하였다. Catechin is main component of polyphenol extracts from green tea, it is associated with prevention of hypertension and atherosclerosis, anti-diabetic effect, antioxidant, antitumor. The purpose of this research is to investigate the effect and its mechanism of green tea catechin on epithelial cancer cell lines in various concentrations and durations. For this study, epithelial cancer cell lines, A549 (lung cancer), EATC (Ehrlich-Lettre ascites tumor cell) were used. Inverted, light, confocal and electron microscopes were applied to find morphological changes. MTT assay, flowcytometric analysis, gel electrophoresis were used to compare severity of cellular damages to control after exposure to 1, 10, 100 and 500 μg/ml catechin for 48 hours. In the A549 cells, after 1 μg/ml and 10 μg/ml catechin treatments, there was no notable changes. However, exposure to 100 μg/ml catechin induced increase of cytoplasmic granules, destruction of lamellar body, inhibition of cell cycle, especially G0/G1. In the early phase of 500 μg/ml catechin administration, decrease of cell population, severe destruction of lamellar bodies and mitochondria, derangement of cell cycle were shown. In the EATC, such as those effects occurred after exposure to lower concentration of catechin than in that of A549 cells. After exposure of 10 μg/ml catechin, rounded-up cells and necrotic cells were found. Whereas, most of cells were under apoptotic changes-cytoplasmic condensation, nuclear fragmentation, cellular shrinkage, ladder pattern in the electrophoresis, when administrated 100 μg/ml catechin. These results suggested that exposure of catechin induced severe cellular damage and growth inhibition in dose- and time-dependent manner. And we confirmed that these effects of catechin were involved with apoptosis, necrosis and cell cycle arrest and were quite different according to cancer type. Therefore, much more research would be demanded before clinical application of catechin to human cancer therapy and this study would be the basic source for further study of green tea.

Association Between Gut Regulatory Hormones and Post-operative Weight Loss Following Gastrectomy in Patients With Gastric Cancer

Hye-Kyung Jung,Chung Hyun Tae,Hye Ah Lee,Ko Eun Lee,Chang Mo Moon,Seong Eun Kim,Ju Young Seoh,Joo-Ho Lee 대한소화기 기능성질환·운동학회 2022 Journal of Neurogastroenterology and Motility (JNM Vol.28 No.3

Background/AimsPost-operative weight loss in patients with gastric cancer lead to a poor quality of life and long-term survival. This study aims to evaluate the effects of gut regulatory hormones on post-operative weight loss in patients with subtotal gastrectomy for gastric cancer. MethodsThis prospective study was conducted for 12 months post-surgery in 14 controls and 13 gastrectomy patients who underwent subtotal gastrectomy for gastric cancer. Serum plasma ghrelin, glucagon-like peptide-1, gastric inhibitory peptide-1, peptide YY, insulin, and homeostatic model assessment for insulin resistance responses to a standardized test meal were recorded at multiple time points before and after gastrectomy at 4 and 12 months. ResultsThe mean weight difference between the pre-operative state and the 4-month period was significantly reduced to 6.6 kg (P = 0.032), but significant weight reduction was not observed from 4 months to 12 months. The plasma levels of glucagon-like peptide-1, gastric inhibitory peptide-1, and peptide YY were significantly increased 4 months postoperatively compared to the pre-operative state (all P = 0.035); however, pre-operative levels and relative changes over a period of 0-4 months of hormones were not correlated with body weight changes. Only the pre-operative ghrelin at peak had a negative correlation with changes in weight reduction in the 4 months after surgery (ρ = −0.8, P = 0.024). ConclusionsSignificant weight reduction was common after subtotal gastrectomy for gastric cancer with a negative correlation pre-operative plasma ghrelin levels. Incretin hormones are modestly but significantly increased after subtotal gastrectomy; however, these changes did not affect the weight changes.

Effect of epidural corticosteroid injection on magnetic resonance imaging findings

( Min Soo Kim ),( Tae Yoon Jeong ),( Yu Seon Cheong ),( Young Wook Jeon ),( So Young Lim ),( Seong Sik Kang ),( In Nam Kim ),( Tsong Bin Chang ),( Hyun Ho Seong ),( Byeong Mun Hwang ) 대한통증학회 2017 The Korean Journal of Pain Vol.30 No.4

Background: Magnetic resonance imaging (MRI) of the spine is the preferred diagnostic tool for pathologic conditions affecting the spine. However, in patients receiving epidural corticosteroid injection (ESI) for treatment of spinal diseases, there is a possibility of misreading of MR images because of air or fluid in the epidural space after the injection. Therefore, we defined the characteristics of abnormal changes in MRI findings following an ESI in patients with low back pain. Methods: We reviewed the medical records of 133 patients who underwent MRI of the lumbar spine within 7 days after ESI between 2006 and 2015.All patients were administered an ESI using a 22-gauge Tuohy needle at the lumbar spine through the interlaminar approach. The epidural space was identified by the loss of resistance technique with air. Results: The incidences of abnormal changes in MRI findings because of ESI were 54%, 31%, and 25% in patients who underwent MRI at approximately 24 h, and 2 and 3 days after ESI, respectively. Abnormal MRI findings included epidural air or fluid, needle tracks, and soft tissue changes. Epidural air, the most frequent abnormal finding (82%), was observed in 41% of patients who underwent MRI within 3 days after injection. Abnormal findings due to an ESI were not observed in MR images acquired 4 days after ESI or later. Conclusions: Pain physicians should consider the possibility of abnormal findings in MR images acquired after epidural injection using the interlaminar approach and the loss of resistance technique with air at the lumbar spine. (Korean J Pain 2017; 30: 281-6)