Cardiac Resynchronization Therapy planning을 위한 MDCT 활용 Coronary venous classification의 유용성

남태현(Tae Hyun Nam), 권순안(Soon Ahn Kwon), 민관홍(Kwan Hong Min), 전은주(Eun Ju Chun) 대한CT영상기술학회 2018 대한CT영상기술학회지 Vol.20 No.1

목적 : Cardiac resynchronization therapy (CRT)는 뉴욕심장협회 (New York Heart Association, NYHA)의 기준 class III 및 IV에 해당하는 환자에게 적용하는 최신 치료 기법이다. 최신 Multi-detector CT (MDCT)로 촬영한 영상은 3차원 재구성을 통해 관상정맥의 평가가 가능해짐에 따라 CRT 계획을 위한 적절한 CT 검사 프로토콜을 제시하고 심장정맥을 표현하는 새로운 분류법을 제시하고자 한다. 대상 및 방법 : 2014년 3월부터 2016년 12월까지 본원을 내원하여 256 MDCT에서 CRT 프로토콜로 심장 CT를 촬영한 189명을 대상으로 하였으며, CT CRT 프로토콜은 Late arterial phase와 venous phase를 촬영하고 조영제는 두번 나누어 주입하는 방법을 사용하였다. 영상의 평가는 정성적 평가와 정량적 평가를 이용하였으며, 정성적 평가는 관상정맥에 대해 “0-5 points scale 평가법”을 사용하였고 정량적 평가는 관상정맥의 유무와 존재하는 각 혈관의 직경을 측정하고 결과값을 토대로 “LPM method”라 명명한 새로운 관상정맥 분류 표기법에 따라 구분해 보았다. “LPM method”는 세 개의 관상정맥을 유무 및 우세한 혈관을 앞으로 배치하여 표현하는 분류법으로 left marginal vein 은 [L, 1], posterior vein of left ventricle은 [P, 2], middle cardiac vein은 [M, 3]로 표기한다. 결과 : 본 논문에서 제시한 CT CRT 프로토콜로 촬영한 모든 환자의 영상에서는 관상정맥의 관찰이 가능했고 (135 excellent, 46 good, 8 fair), 관상정맥의 평가를 토대로 새로운 관상정맥 분류 표기법에 따라 구분해본 결과 189명 중 142명 (75.1 %)의 환자는 기준으로 하는 세관상정맥 (L, P, M)을 모두 관찰 할 수 있는 LPM 그룹으로 나타났으며, 18명 (9.5 %)의 환자는 두 관상정맥 (P, M)을 관찰 할 수 있는 PM그룹으로 나타났고, 23명 (12.2 %)은 두 관상정맥 (L, M)을 관찰 할 수 있는 LM 그룹으로 나타났으며, 2명 (1 %)의 환자가 두 관상정맥 (L,P)을 관찰 할 수 있는 LP그룹으로 나타났다. 분류법으로 표현하지 못한 환자는 4명 (2 %)으로 나타났다. 우세한 혈관의 분류 기준을 포함한 결과로는 LPM-3_1_2 (M>L>P)가 29.8 %로 가장 높게 나타났으며, LPM-3_2_1이 25.7 %, LM-3_1이 11.5 % 그리고 LPM-3_1,2가 10.5 %로 그 뒤를 따랐다. 결론 : 본 논문에서 제시한 CT CRT 프로토콜로 촬영한 환자 모두에게서 관상정맥을 관찰 할 수 있었을 뿐만 아니라 정성적 평과 결과 평균 4.7점으로 나타났다. CRT 시술을 진행하기 전에 MDCT를 활용하고 “LPM method”를 적용하여 시술에 사용되는 관상정맥을 분류하면 시술에 사용되는 fluoroscopy의 사용시간, 조영제의 사용량 그리고 전체 시술시간을 줄일 수 있을 것으로 사료된다.

최저 심박수 구간을 이용한 Coronary artery CT Angiography의 화질 개선에 관한 연구

유지은(Ji-Eun Yoo), 이종민(Jong-Min Lee), 남태현(Tae-Hyun Nam), 권순안(Soon-Ahn Kwon), 대창민(Chang-Min Dae) 대한CT영상기술학회 2018 대한CT영상기술학회지 Vol.20 No.2

목적: 관상동맥 CT 혈관 조영술(Coronary artery CT Angiography, 이하 CCTA) 에서 scan시 심박수가 최저인 구간을 분석하여 새로운 프로트콜을 만들고 최저 심박수 구간에서의 검사가 화질 개선에 미치는 영향에 대해 연구하고자 하였다. 대상 및 방법: 2015년 9월부터 2017년 12월까지 본원에서 CCTA 를 시행한 환자 674명의 심박수 변화를 관찰하여 심박수가 가장 낮아지는 시점을 조사하는 선행 연구를 한 뒤 2017년 8월부터 2018년 1월까지 기존의 숨을 들여 마시고 참는 방송 직후에 coronary scan을 시작하는 프로토콜로 검사한 대조군 172명과 심박수가 가장 낮아지는 시점에서 coronary scan을 시작하도록 프로토콜을 수정하여 검사한 실험군 125명의 영상을 심혈관계 판독의 3명이 5점 척도로 해부학적 영역들이 얼마나 잘 보이는 가에 따라 정성적으로 평가 하였다. CT scanner로 사용한 장비는 본원에서 현재 CCTA 검사에 사용하고 있는 256MDCT(256 iCT, Philips Medical System, The Netherlands) 2대와 spectral CT(IQon spectral CT, Philips Healthcare, Eindhoven, The Netherlands) 1대, 심장 영상 재구성과 scan된 시간 동안의 심박수 변화를 분석하기 위해 workstation은 Extended Brilliance Workspace(Version 4.5,Philips Medical System, The Netherlands)를 사용하였다. 결과: Coronary scan 중 최저 심박수 구간은 breath hold 후 평균 4.5sec가 되었을 때였다. 이를 토대로 대조군과 실험군의 영상을 5점 척도로 비교 평가 한 결과 대조군에서 5점은 40.1%, 4점은 35.5%, 3점은 21.5%, 2점은 2.9%, 1점은 0%의 결과를 나타냈고 실험군에서 5점은 80.8%, 4점은 12%, 3점은 7.2%, 2점과 1점에서는 0%의 결과를 나타냈다. 영상 평가 결과 실험군의 영상이 대조군에 비해 임상적으로 진단 가치가 높은 것으로 나타났다 결론: CCTA에서 최저 심박수 구간에서의 coronary scan 은 화질 개선에 효과적이다. 임상에서 좀 더 나은 심장 영상을 얻기 위한 노력은 지속되어야 하고 이 연구가 조금이나마 도움이 될 수 있으리라 사료된다. Purpose: The aim of this study is finding the lowest heart rate point during breath holding time in Coronary Artery CT Angiography (CCTA) and create a new protocol to improve image quality without motion artifact. Material and Methods: We investigated 674 patients who underwent conventional coronary CT angiography to observe heart rate changes during their breath holding time, from September 2015 to December 2017. After our investigation, total of 172 patients take Coronary Scan with our new protocol which is starting scan at the point of lowest heart rate point while their breath holding time, from August 2017 to January 2018. 256 MDCTs and a 128 MDCT were used for Coronary Scan with each protocol which is appropriately modified by their technical specification. A 3D workstation, Extended Brilliance Workspace v4.5 (EBW 4.5), is used for analyzing heart rate variation during the scanned time. Result: The lowest heart rate of the coronary scan was 4.5 seconds after the breath holding. Based on this factor, we compared the image quality of 172 patients examined using existing protocols and 125 patients examined using a protocol that changed the scan start time to 4.5 seconds after breath holding. As a result, it was estimated that the images tested with our new protocols are clinically more valuable for diagnosis of coronary artery with motion free images than the existing protocols. Conclusion: Scanning coronary scan at the point of lower heart rate interval is very important in improving image quality without motion artifact. Efforts to get better heart images in the clinical environment should continue and this research could prove to be of some use.

Dynamic Abdomen CT 검사 시 Bolus tracking과 Split injection technique을 비교

이재현(Jae Hyun Lee), 정용환(Yong Hwan Chung), 남태현(Tae Hyun Nam), 권순안(Soon Ahn Kwon), 민관홍(Gwan Hong Min) 대한CT영상기술학회 2017 대한CT영상기술학회지 Vol.19 No.1

Purpose : To compare a multi-phase test using bolus tracking and a single-phase test employing the split injection technique in dynamic abdominal computed tomography (CT), to study the influence on exposure dosage and image quality. Materials and Methods : Among patients who underwent dynamic abdominal CT from October to December 2015, patients examined with either bolus tracking (technique A) or split injection (technique B) were included in this study. A CT system and an analysis workstation were used. Technique A involved one contrast medium (CM) injection. Scanning was conducted twice in the arterial phase and portal venous phase. CM injection in technique B comprised two phases: phase 1 and 2. However, scanning was performed once at 90s manually. The exposure dose was compared between the two tests using the DLP value. The images were quantitatively evaluated by measuring the CT number at the location of the aorta, portal vein, and liver parenchyma. Two radiologists qualitatively analyzed the images obtained using techniques A and B on 5-point scale method. Result : The average DLP value was 1123.8 mGy*cm in technique A and 536.5 mGy*cm in technique B. The aorta CT number of technique A and B were achieving the 100% of standard value. The portal vein CT number of technique A and B were achieving 96% of the standard value. The liver parenchyma CT number of technique A and B were fulfilling 100% of the standard value. Qualitative evaluation revealed an average of 4.5 for technique A and 4.3 for technique B in the arterial phase; 4.2 and 4.5, respectively, in the portal phase image; and 4.3 and 4.2, respectively, in the interpretation category. Conclusion : Compared to technique A, which is used currently in dynamic abdominal imaging, technique B that injects contrast medium at regular intervals can reduce the exposure dose by 47% without downgrading Image quality.

Paranasal sinus CT검사시 Virtual Non Contrast 기법을 통한 화질 평가 및선량감소 효과에 대한 연구

김현영(Hyun-Young Kim), 이종민(Jong-Min Lee), 남태현(Tae-Hyun Nam), 권순안(Soon-Ahn Kwon), 대창민(Chang-Min Dae) 대한CT영상기술학회 2018 대한CT영상기술학회지 Vol.20 No.2

목적: Virtual non contrast image(이하 VNC)의 원리는 조영증강영상(enhanced image)을 photon electric image와 compton scattering image로 분석하여 decomposition의 수학적 연산을 통해 iodine no water 영상과 water no iodine 영상으로 나누고 그 중 water no iodine 영상이 VNC이다. 본 연구는 부비동암을 진단하기 위한 PNS CT검사시 VNC기법을 적용하여 재구성된 VNC영상이 화질저하 및 왜곡없이 non-contrast image(이하 NC)를 대체 할 수 있는가에 대해 알아보고자 하였다. 대상 및 방법: 본원에 내원하여 부비동암을 확진 받고 dual- layer detector CT를 사용하여 PNS CT를 시행한 30명을 대상으로 후향적으로 연구를 진행하였으며 화질평가를 위해 VNC와 NC의 같은 위치인 부비동에 발생한 종양에 관심영역(region of interest) 을 설정하여 CT number, noise, signal to ratio(이하 SNR)를 정량적으로 분석하였고 또한 VNC 와 NC의 정성적 평가를 5점만점 척도를 통해 화질을 비교하였다. 선량평가는 CT장비에서 제공되는 dose length product를 이용하였다. 결과: VNC와 NC를 비교하여 측정한 CT number, noise, SNR의 SPSS를 이용한 대응표본 T-검정의 평균, 표준편차 값은 CT number 0.63±0.23, noise -0.15±0.86, SNR 0.06±0.32 이었고 통계적으로 유의한 차이가 없었으며 정성적 평가결과 VNC에서는 평균 5점 척도 82%, 4점 척도 12.7%, 3점 척도 5.3%, 2점과 1점 척도는 0%로 나타났고 NC에서는 평균 5점 척도 평균 88.7%, 4점 척도 10%, 3점 척도 1.3%, 2점과 1점 척도는 0%로 VNC와 NC의 정성적 평가 결과 화질의 차이는 없었다. 선량평가 결과 NC를 획득하기 위한 scan을 시행하지 않음으로써 약 43%의 선량저감 효과를 가져 올 수 있는 결과 값을 나타내었다. 결론: 부비동암을 진단하기 위한 PNS CT검사시 VNC로 NC를 대체하여 검사를 시행 한다면 영상의 질 저하 및 왜곡 없이 선량 감소 효과를 가질 수 있을 것으로 사료된다. Purpose: Virtual non contrast (VNC) is a technically reconstructed “water no iodine” image which is recalculated of material decomposition with energy selective photon counting detector. In this study, we analyzed VNC image of para-nasal sinus CT as a replacement of non-contrast (NC) image without image distortion and quality degradation. Material and methods: Total of 30 patients, who underwent PNS CT with dual layer detector CT, was enrolled for this study, retrospectively. For quantitative image quality analysis, circular ROIs were located at the same location of VNC and NC images. Paired t-test was used for comparison of CT number, noise, and SNR. For qualitative image quality analysis, both VNC and NC images were evaluated by using a 5-point scale method. Dose Length Product (DLP) was used for comparison of exposure dose between PNS CT protocol and PNS (VNC) CT protocol. Result: There was no significant difference in quantitative image analysis between VNC and NC. Paired t-test(SPSS) values of CT number, Noise, and SNR between VNC and NC were as follows; CT number (0.63±0.23), Noise (-0.15±0.86), SNR (0.06±0.32). In qualitative image analysis, both VNC and NC images marked score of 4(very good) and 5(excellent) more than 90% (VNC 94.7%, NC 98.7%). In comparison of DLP, PNS CT protocol averagely exposed 43% higher dose than PNS (VNC) CT protocol. Conclusion: For PNS CT, VNC protocol is highly recommended a substitute technique of NC scan protocol in order to reduce radiation exposure dose without image quality degradation.

폐경기 여성에서 DXA를 이용한 Lateral Vertebral Assessment의 유용성

오유나(Yu Na Oh),전해경(Hae Kyeong Jeon),권순안(Soon An Kwon),민관홍(Kwan Hong Min),김성룡(Seong Ryong Kim) 대한영상의학기술학회 2010 대한영상의학기술학회 논문지 Vol.2010 No.-

Purpose : Osteoporosis is defined as a skeletal disorder characterized by decreased bone strength and increased risk of fracture. Although many vertebral fracture are clinically silent. they are associated with increased risk for subsequent osteoporotic fracture in postmenopausal women. We evaluated the ability of clinicians using dual-energy Lateral vertebral assessment(LVA) to detect prevalent vertebral fracture. Materials and methods : Dual-energy LVA and conventional thoracic and lumbar spine radiography were concurrently obtained in 158 postmenopausal women. Using an established visual semiquantitative system. vertebral fracture were identified individually by a radiologist clinicians on LVA image, and the results were compared with spinal radiograph evaluation by two expert radiologist. and we retroprospectively compare each BMD category. Results : LVA clinicians correctly identified 94% (76/72) of radiographically defined grade 1~3 vertebral fracture among 158 subject. Women(76) with vertebral fracture were divided up by BMD category, osteoporosis in 85%(65), osteopenia in 15%(11). Specifically most of women with vertebral fracture don’t have back pain. they were only 38%(29/76) Conclusion : Thoracic and lumber spine x-ray are the gold standard for vertebral fracture. LVA provides a more practical screening tool due to the lower radiation(0.083mSv) dose and its availability at the point of service for women attending for DXA. May be screening tool for osteoporosis clinical trial in postmenopausal women.

조명 증강 CT 검사시 조영제 혈관외 유출(Extravasation)의 발생률에 영향을 미치는 검사 요소에 관한 연구

박관중(Guan Jung Park), 정용환(Yong Hwan Jung), 권순안(Soon Ahn Kwon), 민관홍(Kwan Hong Min) 대한CT영상기술학회 2017 대한CT영상기술학회지 Vol.19 No.1

Purpose : The purpose of this study is to prevent and predict extravasation incidence. we had investigated the certain patients who experienced extravasation during the CT examination using contrast-media. Materials and Methods : 170,897 CT examination cases using contrast media are investigation subjects during January 2014 to March 2016. we compared and analyzed correlations of extravasation according to the contrast injection rate, CT scan type, patient s age, sex, underlying disease and whether Extravasation Detection Accessory, EDA was used or not. in case of contrast injection rate, 12,912 cases were targets that can be tracked through medical records. Result: Total 118 extravasation occured. In case of using EDA, 63 extravasation occured among 62,774 in total. However, 56 of total were not extravasated by detection and 7(0.01 %) were extravasated. Without EDA, 55(0.05%) extravasation of 108,123 occured. According to injection rates, extravasation occured as follows. In case of injection rates were less than 1 cc/ sec, 8 occured among 585. 15(0.8%) of 1,857 on 1-2cc/sec, 49(0.9%) of 5,753 on 2-3cc/ sec, 42(0.9%) of 4,460 on 3-4cc/sec, 4(1.4%) of 240 on 4cc/sec or more.In case of injection method, when applying bolus technique, 86(73%) extravasation occured. when applying Fixed technique, 32 extravasation occurred. Depending on classifications of CT, extravasation of neuro section was 9(0.1 %) of total 8,653, 15(0.02%) of total 59,453, in chest, 42(0.3%) of total 13,453 in cardiovascular section, 52(0.05%) of total 89,338 in abdomen. In case of gender, extravasation occured as follows. For man, 43(0.05%) of total of 89,453. For women, 75(0.10%) of total of 74,142. Depending on age, extravasation occured as follows.3(0.02%) of total 17,179 less than 40 s, 17(0.05%) of total 32,543 between 40 s and 50 s, 45(0.09%) of total 49,363, between 50 s and 60 s, 58(0.08%) of total 71,812 more than 60 s. In case of disease, extravasation were occured as follows. 9(7.6%) in cerebrovascular disease, 42(35.6%) in cardiovascular disease, 63(53.4%) in cancer, 4(3.4%) in others Conclusion : In order to prevent the probability of extravasation, CT operators must use EDA, regardless of the contrast injection rates in all cases. special care is required when examining the patients who are women using bolus technique and suffering from cancer and more than 50 s.

The Study of the Usefulness of Breathing method using Straw for Larynx CT Examination

채희창(Hee-Chang Chae), 남태현(Tae-Hyun Nam), 서충범(Choong-Beom Seo), 김성관(Seong-Gwan Kim), 권순안(Soon-Ahn Kwon), 대창민(Chang-Min Dae) 대한CT영상기술학회 2019 대한CT영상기술학회지 Vol.21 No.2

Purpose: The study purpose was to investigate the usefulness of straw-blow method to limit the motion artifact of the larynx. Material and Method: 64 MDCTs and a 3D workstation were used for this study. In phantom study, we scan a head phantom with three different angles of straw. We set area of interests at the four anatomical location to measure CT number and noise. The reference value of CT number and noise is set to ±5%. In clinical study, assessment of supraglottis, glottis, subglottis and the glottic angle, the vertical distance of the pyriform sinus and the appearance of laryngeal ventricle were measured. In addition, five points scale method was used as a qualitative analysis. Results: In phantom study, measured CT number and noise were satisfied reference value of ±5%. In clinical study, quantitative assessment results showed that the change rate of supraglottis and subglottis area increased by 22.6% and 8.7%, while the glottis area decreased by 18.2%. The rate of change in the glottic angle decreased by 10.1%. the pyriform sinus increased by 28.1% (left) and 26.2% (right). the laryngeal ventricle was shown that 50 cases in the experimental group. Qualitative evaluation showed that motion artifact didn’t occur with straw-blow method. Conclusions: Straw-blow technique can provide sufficient diagnostic information. Furthermore, high quality image of larynx will be helpful for decision-making of appropriate treatment plan.

The Effect of the Change in the Volume and the Wall Thickness of Stomach by Adjusting Dosage of Water According to Gender and Weight in Stomach CT.

김영한(Yeong-Han Kim), 남태현(Tae-Hyun Nam), 김성관(Sung-Kwan Kim), 채희창(Hee-Chang Chae), 권순안(Soon-Ahn Kwon), 대창민(Chang-Min Dae) 대한CT영상기술학회 2019 대한CT영상기술학회지 Vol.21 No.1

Purpose: We tried to compare the changes of stomach volume size and wall thickness by changes of water amount, as an oral contrast agent, depending on each patient’s gender and weight in stomach CT for pre-operative evaluation of early gastric cancer. Materials and Methods: In phantom study, three syringe phantoms(100 mL, 150 mL, 200 mL) filled with normal saline were scanned 10 times. Volumes of three phantoms were measured by 3D workstation to determine the accuracy and reproducibility of the measured values. In clinical study, 211 control subjects who ingested the certain amount of water according to the existing protocol(drinking same amount of water), and 194 subjects who ingested the amount of water adjusted according to one’s gender and weight, the volumes of water in stomach of them were measured by reconstructing the workstation and assessed stomach body and antral wall as quantitative analysis. Two independent observers evaluated expansion of the gastric on a 4-point scale method as a qualitative analysis. Results: In phantom study, result of difference percentages of volume measurements were 0.007% (100 mL), 0.004% (150 mL) and 0.01% (200 mL). All phantom measurements were satisfied with standard tolerance ranges within ±5%. In clinical study, groups of male 60-70 kg, 70 to 80 kg and 80 kg or more in the experimental group, the amounts of remaining water in gastric were 7.5%, 37.9%, and 38 % increased more than the control group. The average thickness of the stomach walls in three groups were measured 0.27±0.01 mm, 0.20±1.30 mm, 0.09±0.35 mm thinner than the control group which shows better results for evaluate early gastric cancer. In qualitative analysis, points of 3 and 4 were increased in experimental group. Observer 1 gave 44.6% of points of 3 and 4 in the control group and 58.8% in the experimental group. Observer 2 gave 44.1% of points of 3 and 4 in the control group and 61.9% in the experiment group. Both evaluators gave high scores. Conclusions: Changing amount of water agent depending on each patient’s gender and weight shows not only sufficient of remaining water in stomach but it also distends stomach wall which is easy to distinguish between early gastric cancer and advanced gastric cancer. Additionally, this protocol reduces burdens of drinking water because we set the appropriate amount of water by gender and weight following anatomically and physiologically.

유두 분비물을 원인으로 하여 시행한 Galactography의 유용성에 관한 고찰 : Mammography, Breast sonography와 비교

조희정(Hee Jeong Jo),전해경(Hae Kyeong Jeon),김서현(Seo Hyeon Kim),최진희(Jin Hee Choi),권순안(Soon An Kwon),민관홍(Kwan Hong Min),김성룡(Seong Ryong Kim) 대한영상의학기술학회 2009 대한영상의학기술학회 논문지 Vol.2009 No.-

Purpose : To evaluate the usefulness of galactography compared with mammography and breast sonography in patients with nipple discharge. Materials and methods : This study was retrospectively conducted in 79 patients with nipple discharge who underwent galactography in our hospital from April in 2004 to July in 2008. Telebrix was used as a contrast medium There were digital mammography (GE Senography TM 2000D) and sono medical system (Philips Medical system, Bothwll, WA / HDl-5000, iU22) as a device for this study. First of all, we accessed Galactography, Mammography and breast sonography using BI-RADS classification and analyze pathology from surgery and biopsy over BI-RADS C3 lesion. The last, we find out the availability of galactography compared with pathology and analyzed the result of galactography. Results : Among 79 patients who underwent galactography, 55 were revealed as over BI-RADS C3 lesion. In mammography, 20 of that 55 were normal as Bl-RADS C1 or C2 lesion, other 12 were diagnosed as BI-RADS C1 or C2 lesion, then recommended further study. In breast sonography, 43 of 55 were consistent with BI-RADS C3 lesion. 9 were not found the lesion in mammography and breast sonography, but found the suspicious lesion in galactography. Conclusion : Galactography is useful for the patient with nipple discharge diagnosed breast disease, especially intraductal papilloma (IDP).

Cam Type Femoro Acetabular Impingement Syndrome 진단에 이용되는 Alpha Angle 측정에 있어 Dunn View의 유용성에 관한 고찰

김현영(Hyun‐,Young Kim),김상현(Sang‐,Hyeon Kim),정한별(Han‐,Byeol Jeong),권순안(Soon-An kwon),민관홍(Gwan‐,Hong Min) 대한영상의학기술학회 2012 대한영상의학기술학회 논문지 Vol.2012 No.-

적: Cam type Femoro Acetabular Impingement syndrome (FAI) 진단에 있어서 α각 (alpha angle)은 중요한 요소 중 하나이다. 이에 본 논문에서는 Dunn view (45˚,90˚)가 α각 측정에서 있어서 얼마나 유용한지를 Hip MRA와 AP view, Frog leg view, Trans Lateral view와의 비교 분석을 통해서 알아보고자 하였다. 대상 및 방법: 성인 남녀 66명을 대상으로 하였고 장비는 DR (digital diagnost TH, Philips, Netherland), MRI (Achieva 3.0T scanner, Philips, Netherlands)로 검사 하였고, α각 측정은 영상의학과 전문의 1명과 숙련된 방사선사 3명이 각각 측정 하였다. Hip MRA 에서 측정된 값을 Gold Standard로 하였고 Dunn 45˚ view, Dunn 90˚ view, AP view, Frog leg view와 Trans Lateral view의 측정 값 들을 각 각 정규성 검정을 통해 대응검정 T분석과 pearson 상관계수로 비교 분석 하였다. 결과: SPSS 통계 프로그램을 통해 분석하였으며 각각 측정값의 평균과 표준 편차는 MRA 47.3120˚±6.5480, AP view 63.4644˚±15.4772, Frog leg view 56.5708˚±9.9862, Trans Lateral view 49.0558˚±5.4949, Dunn 45˚ view 54.9586˚±8.4270, Dunn 90˚ view 47.8489˚±6.5138로 측정되었다. MRA와 Dunn 90˚ view의 평균차이는 0.3505, MRA와 Dunn 45˚ view는 0.9367, MRA와 Trans Lateral view는 0.7303, MRA와 Frog leg view는 1.3372, MRA와 AP view는 2.1088 이었다. MRA와 Dunn 90˚ view 는 p>0.05로 통계적으로 유의한 차이가 없었으며, MRA와 Dunn 45˚ view, Trans Lateral view, Frog leg view, AP view는 p<0.05로 통계적으로 유의한 차이가 있었다.결론: Dunn 90˚ view는 α각 측정이 비교적 정확하고 환자에게 시간, 비용 절감이 가능하며 조영제를 사용하지 않는 비침습적 검사라는 장점을 가진다. 그러나 통증이 심할 경우 Dunn 45˚, 90˚의 정확한 검사자세를 취할 수 없다는 점과 Dunn 45˚, 90˚ view의 검증된 device 및 accessory가 제작 되지 않아 검사자마다 flexion 및 abduction의 각도가 상이할 수 있다는 한계점이 있었다. 그러나 앞선 MRA와의 비교 결과에서도 알 수 있듯이 Dunn 90˚ view는 α각을 측정 하는데 매우 유용한 검사법이며 MRA 없이도 cam type FAI를 진단하는데 도움이 될 수 있다. Purpose: In the diagnosis of cam‐type FAI (Femoro Acetabular Impingement) syndrome, α angle is one of important factors. This study purposed to test the usefulness of Dunn view (45˚,90˚) in measuring α angle through comparative analysis of hip MRA and simple X‐ray tests AP view, frog leg view, and trans‐lateral view. Materials and methods: The subjects of this study were 66 adult men and women, and test was conducted with DR (digital diagnost TH, Philips, Netherlands) and MRI (Achieva 3.0T scanner, Philips, Netherlands). In addition, α angle was measured by a radiologist and three experienced radiological technologists. The value measured in hip MRA was used as the Gold Standard, and values measured from Dunn 45˚ view, Dunn 90˚ view, AP view, frog leg view and trans‐lateral view were analyzed comparatively by paired t‐test and Pearson’s correlation through normality test. Results: Data were analyzed through SPSS, and the mean and standard deviation of measurements were MRA 47.3120˚±6.5480, AP view 63.4644˚±15.4772, frog leg view 56.5708˚±9.9862, trans‐lateral view 49.0558˚±5.4949, Dunn 45˚ view 54.9586˚ ±8.4270, and Dunn 90˚ view 47.8489˚±6.5138. Difference in mean value was 0.3505 between MRA and Dunn 90˚ view, 0.9367 between MRA and Dunn 45˚ view, 0.7303 between MRA and trans‐lateral view, 1.3372 between MRA and frog leg view, and 2.1088 between MRA and AP view. The difference between MRA and Dunn 90˚ view was not statistically significant (p>0.05), and the differences between MRA and Dunn 45˚ view, tans‐lateral view, frog leg view and AP view were statistically significant (p<0.05). Conclusion: Dunn 90˚ view was relatively accurate in measuring α angle. In addition,it saves time and cost for the patient, and is a non‐invasive examination without using contrast agent. On the other hand, it has the limitations that the patient cannot take the correct examination posture of Dunn 45˚ and 90˚ if pain is severe and that the angles of flexion and abduction may vary among examiners because there are no proven device and accessory for Dunn 45˚ and 90˚ view. As in the results of comparison with MRA shown above, however, Dunn 90˚ view is a very useful method to measure α angle and can be useful to diagnose cam‐type FAI without MRA.