• Korean Journal of Radiology
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• 제23권11호
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• pp.1044-1054
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• 2022

Objective: This study aimed to investigate whether a deep learning reconstruction (DLR) method improves the image quality, stent evaluation, and visibility of the valve apparatus in coronary computed tomography angiography (CCTA) when compared with filtered back projection (FBP) and hybrid iterative reconstruction (IR) methods. Materials and Methods: CCTA images of 51 patients (mean age ± standard deviation [SD], 63.9 ± 9.8 years, 36 male) who underwent examination at a single institution were reconstructed using DLR, FBP, and hybrid IR methods and reviewed. CT attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and stent evaluation, including 10%-90% edge rise slope (ERS) and 10%-90% edge rise distance (ERD), were measured. Quantitative data are summarized as the mean ± SD. The subjective visual scores (1 for worst -5 for best) of the images were obtained for the following: overall image quality, image noise, and appearance of stent, vessel, and aortic and tricuspid valve apparatus (annulus, leaflets, papillary muscles, and chordae tendineae). These parameters were compared between the DLR, FBP, and hybrid IR methods. Results: DLR provided higher Hounsfield unit (HU) values in the aorta and similar attenuation in the fat and muscle compared with FBP and hybrid IR. The image noise in HU was significantly lower in DLR (12.6 ± 2.2) than in hybrid IR (24.2 ± 3.0) and FBP (54.2 ± 9.5) (p < 0.001). The SNR and CNR were significantly higher in the DLR group than in the FBP and hybrid IR groups (p < 0.001). In the coronary stent, the mean value of ERS was significantly higher in DLR (1260.4 ± 242.5 HU/mm) than that of FBP (801.9 ± 170.7 HU/mm) and hybrid IR (641.9 ± 112.0 HU/mm). The mean value of ERD was measured as 0.8 ± 0.1 mm for DLR while it was 1.1 ± 0.2 mm for FBP and 1.1 ± 0.2 mm for hybrid IR. The subjective visual scores were higher in the DLR than in the images reconstructed with FBP and hybrid IR. Conclusion: DLR reconstruction provided better images than FBP and hybrid IR reconstruction.

• 대한핵의학회지
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• 제39권4호
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• pp.246-251
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• 2005

목적: 심근관류 스펙트 검사에서 감쇠의 영향을 보정하기 위해 여러 가지 방법들이 사용되어 왔다. 본 연구는 CT를 이용한 감쇠보정이 관상동맥조영술이 정상인 환자들을 대상으로 하였을 때 어떠한 영향을 주는지 알아보고 기존의 감쇠보정방법들과 차이가 있는지를 알아보고자 하였다. 대상 및 방법: 관상동맥질환이 의심되어 심근 SPECT/CT를 시행한 환자들 중 관상동맥조영술상 정상소견을 보인 25명에서, Pryor 등의 방법으로 관상동맥질환의 위험도가 5.0% 미만인 15명의 환자를 대상으로 하였다. (남 6, 여 9, 평균연령 $58{\pm}8$세). CT가 장착된 Millennium VG (GE) 카메라로 감쇠보정을 하였으며, 영상의 판독은 육안분석과 극성지도를 이용한 정량적 분석을 시행하였다. 정량적 분석의 경우 극성지도 상에서 각 심근벽의 섭취율(최대 섭취율에 대한 %)을 구하여 감쇠보정을 하지 않은 영상과 감쇠보정을 한 영상을 비교하였다. 결과: 육안분석에서 감쇠보정을 한 경우 하벽의 섭취는 증가한 반면, 전벽과 심첨부 및 격벽의 섭취는 감소하였다. 간에서의 섭취도 감쇠보정을 한 경우에 증가하였다. 정량분석에서는 심첨부의 경우 감쇠보정 후 섭취율이 감소하였고, 하벽의 경우 증가하였다. 하벽의 경우 감쇠보정을 하여 판독에 도움을 받을 수 있었고, 반면 전벽이나 심첨부의 경우 감쇠보정 후 판독에 어려움이 있었다. 결론: 하벽의 경우 CT를 이용한 감쇠보정을 한 경우 판독에 도움이 되었으며, 감쇠보정전 영상이 정상인 경우 심첨부나 전벽등의 판독시는 주의가 필요하다.

• Nuclear Medicine and Molecular Imaging
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• 제43권6호
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• pp.513-518
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• 2009

목적: 관상동맥질환은 치료법이 개발되어 있는 매우 치명적인 질환이므로 빠른 진단과 치료방법의 결정 및 재발이나 앞으로의 위험성에 대한 평가가 중요하다. 최근에는 병태생리를 반영하는 심근관류 SPECT와 해부학적 영상인 CT의 퓨전 영상에 대한 기대가 증가되고 있다. 저자들은 심근관류 SPECT에서 가역적인 관류 변화가 있었던 환자에서 퓨전영상의 유용성에 대하여 후향적 분석을 하였다. 대상 및 방법: 다기관 공동 연구로 전국 5개 대학 병원에서 48명의 환자(남:녀=26:22, 나이: $63.3{\pm}10.4$ 세)를 대상으로 하였다. 환자들은 아데노신 약물부하로 Tc-99m 세스타미비 혹은 테트로포스민을 이용하여 휴식기 및 부하기 심근관류 SPECT와 64채널 다중검출 CT를 이용하여 CTA를 시행하였으며, 소프트웨어(CardIQ, GE healthcare)로 두 영상을 퓨전하여 두 검사의 진단 정확도를 비교하였다. 결과: 48명의 환자를 대상으로 144개의 관상동맥에 대하여 분석하였다. 이들 중에서 단일 혈관 질환 환자가 17명, 두혈관 질환 환자가 15명, 세혈관 질환 환자가 11명, 유의한 협착이 없는 환자가 3명이었고, 2명의 환자에서 좌측 주관상동맥의 협착이 발견되었다. 좌측 주관상동맥에 협착이 있었던 2명을 제외하고, 관상동맥의 협착을 진단하는데에 있어 심근관류 SPECT는 민감도 68.8%, 특이도 70.7%이었으며, 퓨전영상은 각각 82.5%, 79.3%, 이었고, 두 검사의 진단 정확도에는 유의한 차이가 있었다(p<0.05). 퓨전영상에서는 좌측 주관상동맥의 협착을 포함하여 전체 82개의 협착 혈관 중 68개의 협착을 진단하였고, 심근관류 SPECT만으로 분석할 때보다 11개의 협착 병변을 추가로 확인할 수 있었다. 또한 애매한 관류저하를 보였던 3개의 관류저하 부위를 허혈 병변에서 제외할 수 있었으며, 4개의 병변은 관류저하를 유발하는 관상동맥을 수정하였다. 3개의 허혈 병변에 대하여서는 허혈 관련 병변 분절을 정확하게 국소화할 수 있었다. 결론: 심근 관류 SPECT와 CTA의 3차원 퓨전 영상은 관상동맥 질환의 병태생리를 포괄적으로 이해할 수 있도록 도움을 주고, 진단의 정확도를 높일 수 있을 것으로 사료된다.

• Korean Journal of Radiology
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• 제23권10호
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• pp.939-948
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• 2022

Objective: Evidence supports the efficacy of coronary computed tomography angiography (CCTA)-based risk scores in cardiovascular risk stratification of patients with suspected coronary artery disease (CAD). We aimed to compare two CCTA-based risk score algorithms, Leiden and Confirm scores, in patients with diabetes mellitus (DM) and suspected CAD. Materials and Methods: This single-center prospective cohort study consecutively included 1241 DM patients (54.1% male, 60.2 ± 10.4 years) referred for CCTA for suspected CAD in 2015-2017. Leiden and Confirm scores were calculated and stratified as < 5 (reference), 5-20, and > 20 for Leiden and < 14.3 (reference), 14.3-19.5, and > 19.5 for Confirm. Major adverse cardiovascular events (MACE) were defined as the composite outcomes of cardiovascular death, nonfatal myocardial infarction (MI), stroke, and unstable angina requiring hospitalization. The Cox model and Kaplan-Meier method were used to evaluate the effect size of the risk scores on MACE. The area under the curve (AUC) at the median follow-up time was also compared between score algorithms. Results: During a median follow-up of 31 months (interquartile range, 27.6-37.3 months), 131 of MACE were recorded, including 17 cardiovascular deaths, 28 nonfatal MIs, 64 unstable anginas requiring hospitalization, and 22 strokes. An incremental incidence of MACE was observed in both Leiden and Confirm scores, with an increase in the scores (log-rank p < 0.001). In the multivariable analysis, compared with Leiden score < 5, the hazard ratios for Leiden scores of 5-20 and > 20 were 2.37 (95% confidence interval [CI]: 1.53-3.69; p < 0.001) and 4.39 (95% CI: 2.40-8.01; p < 0.001), respectively, while the Confirm score did not demonstrate a statistically significant association with the risk of MACE. The Leiden score showed a greater AUC of 0.840 compared to 0.777 for the Confirm score (p < 0.001). Conclusion: CCTA-based risk score algorithms could be used as reliable cardiovascular risk predictors in patients with DM and suspected CAD, among which the Leiden score outperformed the Confirm score in predicting MACE.

• Journal of Korean Neurosurgical Society
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• 제51권3호
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• pp.155-159
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• 2012

The treatment of bilateral vertebral artery dissecting aneurysms (VADAs) presenting with subarachnoid hemorrhage (SAH) is still challenging. The authors report a rare case of bilateral VADA treated with coil trapping of ruptured VADA and covered stents implantation after multiple unsuccessful stent assisted coiling of the contralateral unruptured VADA. A 44-year-old woman was admitted to our hospital because of severe headache and sudden stuporous consciousness. Brain CT showed thick SAH and intraventricular hemorrhage. Cerebral angiography demonstrated bilateral VADA. Based on the SAH pattern and aneurysm configurations, the right VADA was considered ruptured. This was trapped with endovascular coils without difficulty. One month later, the contralateral unruptured VADA was protected using a stent-within-a-stent technique, but marked enlargement of the left VADA was detected by 8-months follow-up angiography. Subsequently two times coil packing for pseudosacs resulted in near complete occlusion of left VADA. However, it continued to grow. Covered stents graft below the posterior inferior cerebellar artery (PICA) origin and a coronary stent implantation across the origin of the PICA resulted in near complete obliteration of the VADA. Covered stent graft can be used as a last therapeutic option for the management of VADA, which requires absolute preservation of VA flow.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1021-1030
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• 2018

Objective: We evaluated the effect of various patient characteristics and time-density curve (TDC)-factors on the test bolus-affected vessel enhancement on coronary computed tomography angiography (CCTA). We also assessed the value of generalized linear regression models (GLMs) for predicting enhancement on CCTA. Materials and Methods: We performed univariate and multivariate regression analysis to evaluate the effect of patient characteristics and to compare contrast enhancement per gram of iodine on test bolus (${\Delta}HUTEST$) and CCTA (${\Delta}HUCCTA$). We developed GLMs to predict ${\Delta}HUCCTA$. GLMs including independent variables were validated with 6-fold cross-validation using the correlation coefficient and Bland-Altman analysis. Results: In multivariate analysis, only total body weight (TBW) and ${\Delta}HUTEST$ maintained their independent predictive value (p < 0.001). In validation analysis, the highest correlation coefficient between ${\Delta}HUCCTA$ and the prediction values was seen in the GLM (r = 0.75), followed by TDC (r = 0.69) and TBW (r = 0.62). The lowest Bland-Altman limit of agreement was observed with GLM-3 (mean difference, $-0.0{\pm}5.1$ Hounsfield units/grams of iodine [HU/gI]; 95% confidence interval [CI], -10.1, 10.1), followed by ${\Delta}HUCCTA$ ($-0.0{\pm}5.9HU/gI$; 95% CI, -11.9, 11.9) and TBW ($1.1{\pm}6.2HU/gI$; 95% CI, -11.2, 13.4). Conclusion: We demonstrated that the patient's TBW and ${\Delta}HUTEST$ significantly affected contrast enhancement on CCTA images and that the combined use of clinical information and test bolus results is useful for predicting aortic enhancement.

• Journal of Chest Surgery
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• 제48권1호
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• pp.33-39
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• 2015

Background: This study aimed to investigate sternal healing over time and the incidence of poor sternal healing in patients undergoing coronary artery bypass graft (CABG) surgery using bilateral internal thoracic arteries. Methods: This study enrolled 197 patients who underwent isolated CABG using skeletonized bilateral internal thoracic arteries (sBITA) from 2006 through 2009. Postoperative computed tomography (CT) angiography was performed on all patients at monthly intervals for three to six months after surgery. In 108 patients, an additional CT study was performed 24 to 48 months after surgery. The axial CT images were used to score sternal fusion at the manubrium, the upper sternum, and the lower sternum. These scores were added to evaluate overall healing: a score of 0 to 1 reflected poor healing, a score of 2 to 4 was defined as fair healing, and a score of 5 to 6 indicated complete healing. Medical records were also retrospectively reviewed to identify perioperative variables associated with poor early sternal healing. Results: Three to six months after surgery, the average total score of sternal healing was $2.07{\pm}1.52$ and 68 patients (34.5%) showed poor healing. Poor healing was most frequently found in the manubrium, which was scored as zero in 72.6% of patients. In multivariate analysis, the factors associated with poor early healing were shorter post-surgery time, older age, diabetes mellitus, and postoperative renal dysfunction. In later CT images, the average sternal healing score improved to $5.88{\pm}0.38$ and complete healing was observed in 98.2% of patients. Conclusion: Complete sternal healing takes more than three months after a median sternotomy for CABG using sBITA. Healing is most delayed in the manubrium.

• Tuberculosis and Respiratory Diseases
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• 제56권4호
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• pp.420-425
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• 2004

관상동맥-폐동맥 누공은 비교적 드문 질환으로 선천적 원인이 대부분이나 최근 흉부 시술이나 방사선 치료의 증가로 점차 후천적 원인이 많아지는 추세이다. 증상이 비특이적이어서 진단이 늦어질 수 있어 주의를 요한다. 저자들이 경험한 환자는 기존의 폐질환 증상 때문에 심장 혈관 질환의 진행을 예측하기 어려웠다. 약간의 논쟁이 있으나 원인에 계 없이 크기가 작은 누공에서는 추적관찰이, 중등도 이상의 크기이거나 확장 가능성이 있는 경우에는 누공을 막거나 원인혈관을 제거하는 방법이 장되고 있다. 예후는 대체로 양호한 편이다.

• Korean Journal of Radiology
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• 제22권12호
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• pp.1964-1973
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• 2021

Objective: To investigate the diagnostic performance of CT fractional flow reserve (CT-FFR) for myocardial bridging-related ischemia using dynamic CT myocardial perfusion imaging (CT-MPI) as a reference standard. Materials and Methods: Dynamic CT-MPI and coronary CT angiography (CCTA) data obtained from 498 symptomatic patients were retrospectively reviewed. Seventy-five patients (mean age ± standard deviation, 62.7 ± 13.2 years; 48 males) who showed myocardial bridging in the left anterior descending artery without concomitant obstructive stenosis on the imaging were included. The change in CT-FFR across myocardial bridging (ΔCT-FFR, defined as the difference in CT-FFR values between the proximal and distal ends of the myocardial bridging) in different cardiac phases, as well as other anatomical parameters, were measured to evaluate their performance for diagnosing myocardial bridging-related myocardial ischemia using dynamic CT-MPI as the reference standard (myocardial blood flow < 100 mL/100 mL/min or myocardial blood flow ratio ≤ 0.8). Results: ΔCT-FFR_systolic (ΔCT-FFR calculated in the best systolic phase) was higher in patients with vs. without myocardial bridging-related myocardial ischemia (median [interquartile range], 0.12 [0.08-0.17] vs. 0.04 [0.01-0.07], p < 0.001), while CT-FFR_systolic (CT-FFR distal to the myocardial bridging calculated in the best systolic phase) was lower (0.85 [0.81-0.89] vs. 0.91 [0.88-0.96], p = 0.043). In contrast, ΔCT-FFR_diastolic (ΔCT-FFR calculated in the best diastolic phase) and CT-FFR_diastolic (CT-FFR distal to the myocardial bridging calculated in the best diastolic phase) did not differ significantly. Receiver operating characteristic curve analysis showed that ΔCT-FFR_systolic had largest area under the curve (0.822; 95% confidence interval, 0.717-0.901) for identifying myocardial bridging-related ischemia. ΔCT-FFR_systolic had the highest sensitivity (91.7%) and negative predictive value (NPV) (97.8%). ΔCT-FFR_diastolic had the highest specificity (85.7%) for diagnosing myocardial bridging-related ischemia. The positive predictive values of all CT-related parameters were low. Conclusion: ΔCT-FFR_systolic reliably excluded myocardial bridging-related ischemia with high sensitivity and NPV. Myocardial bridging showing positive CT-FFR results requires further evaluation.

• 핵의학기술
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• 제23권2호
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• pp.38-42
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• 2019

관상동맥 석회화 검사에 컴퓨터단층촬영(Comtuted tomography, CT)을 사용하지만 고위험군인 미세석회화 감별에는 어려움이 있다. $^{18}F$-sodium fluoride ($^{18}F-NaF$)가 미세석회화를 진단하는데 매우 유용하다는 연구가 해외에서 보고되고 있다. 본 논문에서는 $^{18}F-NaF$ PET 영상으로 석회화를 정량평가 하고 그 유용성을 알아보고자 한다. 환자는 총 45명($67.1{\pm}6.9$세)으로 $^{18}F-NaF$을 250 MBq 주입하고 1시간 뒤 30분간 영상을 획득하였다. 장비는 Discovery 710 (GE Healthcare, MI, USA)을 사용하였으며 모든 환자는 PET 검사 전 혈관조영CT (CTAngiography, CTA)를 촬영 하였다. 석회화의 SUVmax를 측정하고 좌심방의 배후방사능을 측정하여 Target to Background (TBR) 구한 뒤 정량 분석하였다. ROC 곡선(Receiver Operating Characteristic Curve)을 통하여 고위험군을 분류하였다. 융합영상에서 관상동맥 석회화는 226개로 나왔으며 SUVmax는 $1.15{\pm}0.39$으로 나왔다. 28명(62%)에서 58개가 고위험군으로(TBR>1.25)분류 되었다. 나머지 168개는 $TBR{\leq}1.25$로 나왔다. $^{18}F-NaF$ PET 영상으로 미세석회화의 정량평가가 가능하였고 고위험군을 분류할 수 있었다. 혈관조영CT와 $^{18}F-NaF$ PET을 병행한다면 위험도가 높은 미세석회화를 조기 진단하는 새로운 영상 진단법이 될 수 있을 것으로 사료된다.