• Journal of Korean Neurosurgical Society
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• 제57권6호
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• pp.432-435
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• 2015

Moyamoya disease is a unique cerebrovascular disorder characterized by idiopathic progressive stenosis at the terminal portion of the internal carotid artery (ICA) and fine vascular network. The aim of this review is to present the clinical application of quantitative digital subtraction angiography (QDSA) in pediatric moyamoya disease. Using conventional angiographic data and postprocessing software, QDSA provides time-contrast intensity curves and then displays the peak time ($T_{max}$) and area under the curve (AUC). These parameters of QDSA can be used as surrogate markers for the hemodynamic evaluation of disease severity and quantification of postoperative neovascularization in moyamoya disease.

• 동의생리병리학회지
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• 제21권2호
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• pp.578-581
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• 2007

Moyamoya disease is characterized by the angiographic findings of bilateral occlusion of the distal portion of the internal carotid arteries with a vascular network at the base of the brain. The typical findings on conventional angiography and magnetic resonance imaging usually confirm the correct diagnosis of moyamoya disease. We experienced a 11-year-old girl with moyamoya disease showing repeated transient ischemic attacks and we report on this case with a review of the literature.

• 대한방사선기술학회지:방사선기술과학
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• 제7권1호
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• pp.13-21
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• 1984

Subtraction is an essential technic to improve imaging quality in various radiological procedures. The limitations of subtraction, however, are well known. Blurred under-subtraction (BUS) method has been suggested to overcome and compensate these limitations. Ten cases of angiography were subtracted by conventional subtraction and BUS technic. Results of this study revealed that BUS method is simple to perform and imaging quality obtained by BUS is excellent. Comparing to conventional subtraction, BUS method has advantages. For example, BUS need no mask film or no immobilization of patient during examination. Improvement of imaging Qualify is achieved by edge enhancement, homogeneous blurring of background density and increasing contrast. With emphasis of its simplicity in technic, we would report that BUS method is a useful adjunct imaging technic in various radiological procedures.

• 한국방사선학회논문지
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• 제2권1호
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• pp.17-21
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• 2008

본 연구에서는 뇌수막종이 늦게 조영증강 된다는 점을 착안하여 뇌수막종을 최대 조영 증강시킨 검사를 시작하였다, 검사 후에 두개내의 수막종과 혈관과의 관계를 알아보고 전산화 단층 촬영 조영술의 3차원 CT 영상 기법(이하, 3차원 CT 영상 기법)과 고식적 혈관 촬영 조영술의 영상을 비교하였다. 연구대상은 3차원 CT 영상 기법과 고식적 혈관 촬영 조영술을 병행 시행하였던 6명의 환자를 대상으로 하였으며. 그 중 추체접형골동사대부 5예, 방시상동에 생긴 1예였다. 검사방법으로는 조영제를 초당 3/120 ml를 주입하여, GE Medical System Program(smart prep)을 이용하여 CT Number 값이 100에 도달한 후, 검사를 시작하였다. 스캔파라미터는 조영제가 모두 주입된 직후에 1.25 mm / 3.75 mm, HQ-Mode로 scan한 후 1 mm interval로 재구성하였다. 검사한 영상을 3D-Med Software Program(Rapidia)을 이용하여 3차원 CT 영상 기법으로 영상을 재구성한 다음 고식적 혈관 촬영 조영술과 비교하였다. 결과를 살펴보면 뇌수막종의 최대조영 시간은 조영제을 주입한 후 약120-180초에 혈관과 종양과의 관계를 가장 잘 구별할 수 있었다. 3차원 CT 영상 기법으로 재구성한 6예는 모두 종양과 혈관과의 관계를 잘 구별할 수 있었다. 또한 종양과 동반된 동맥류도 1예에서 잘 보여주었다. 이를 종합하여 보면 두 개 내 뇌수막종의 환자에서 조영제를 주입하여 3차원 CT 영상을 시행하였던 영상은 종양과 혈관과의 관계를 입체적으로 구분할 수 있어 수술에 많은 도움이 되었다.

• The Korean Journal of Pain
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• 제28권2호
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• pp.105-108
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• 2015

Background: The most definitive diagnosis of neck pain caused by facet joints can be obtained through cervical medial branch blocks (CMBBs). However, intravascular injections need to be carefully monitored, as they can increase the risk of false-negative blocks when diagnosing cervical facet joint syndrome. In addition, intravascular injections can cause neurologic deficits such as spinal infarction or cerebral infarction. Digital subtraction angiography (DSA) is a radiological technique that can be used to clearly visualize the blood vessels from surrounding bones or dense soft tissues. The purpose of this study was to compare the rate of detection of intravascular injections during CMBBs using DSA and static images obtained through conventional fluoroscopy. Methods: Seventy-two patients were included, and a total of 178 CMBBs were performed. The respective incidences of intravascular injections during CMBBs using DSA and static images from conventional fluoroscopy were measured. Results: A total of 178 CMBBs were performed on 72 patients. All cases of intravascular injections evidenced by the static images were detected by the DSAs. The detection rate of intravascular injections was higher from DSA images than from static images (10.7% vs. 1.7%, P < 0.001). Conclusions: According to these findings, the use of DSA can improve the detection rate of intravascular injections during CMBBs. The use of DSA may therefore lead to an increase in the diagnostic and therapeutic value of CMBBs. In addition, it can decrease the incidence of potential side effects during CMBBs.

• 대한방사선기술학회지:방사선기술과학
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• 제32권3호
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• pp.299-306
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• 2009

MDCT의 시간분해능 향상과 등방성 해상능(isotrophic resolution) 영상의 획득, 그리고 지능적인 심전도 동조를 바탕으로 하여 심혈관 질환의 효과적인 진단검사로 인정받고 있는 후향적 심전도 동조화(retrospective ECG gating) 하의 coronary CT angiography는 상대적으로 많은 환자선량을 제공함으로 인해 우수한 진단방법으로서의 장점을 반감시키고 있다. 이에 각 장치 제조사에서는 환자선량을 감소시키는 방법의 연구가 활성화되어 왔으며, 이의 일환으로 지능적인 cardiac dose modulation 기술과 전향적 심전도 동조화(prospective ECG gating)를 사용한 sequential scan이 도입되고 있다. 이에 본 연구에서는 64 채널 MDCT에서 54 kg, 163 cm인 여성 인체모형팬텀을 대상으로 하고 형광유리선량계를 사용하여 후향적 심전도 동조화 하의 coronary CT angiography 프로토콜에서 환자선량의 정량적 평가와 환자선량 감소를 위해 본원에서 선택적으로 적용하고 있는 5가지 검사 프로토콜을 적용하였을 경우의 effective dose와 중요 부위의 organ dose를 측정 비교하여 다음과 같은 결과를 얻었다. 1) Dose modulation없이 120 kVp와 210 mAs의 노출조건으로 retrospectively ECG gated helical scan으로 시행한 conventional coronary CT angiography 프로토콜의 effective dose는 17.8 mSv였으며, 심장의 organ dose는 103.8 mGy였다. 2) 관전압을 120 kVp에서 100 kVp로 낮추었을 경우 effective dose는 11.0 mSv로 conventional coronary CT에 비해 38.2%가 감소하였으며, 심장은 67.3 mGy로 45.2%가 감소하였다. 3) Cardiac dose modulation을 적용한 경우 effective dose는 13.3 mSv로 conventional coronary CT에 비해 25.3%가 감소하였으며, 심장은 80.0 mGy로 22.9%가 감소하였다. 4) 100 kVp의 저관전압과 cardiac dose modulation을 적용한 경우 effective dose는 8.1 mSv로 conventional coronary CT angiography에 비해 54.5%가 감소하였으며, 심장은 49.5 mGy로 52.3%가 감소하였다.

• Korean Journal of Radiology
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• 제25권6호
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• pp.575-588
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• 2024

Objective: Differentiating intracranial aneurysms from normal variants using CT angiography (CTA) or MR angiography (MRA) poses significant challenges. This study aimed to evaluate the efficacy of proton-density MRA (PD-MRA) compared to high-resolution time-of-flight MRA (HR-MRA) in diagnosing aneurysms among patients with indeterminate findings on conventional CTA or MRA. Materials and Methods: In this retrospective analysis, we included patients who underwent both PD-MRA and HR-MRA from August 2020 to July 2022 to assess lesions deemed indeterminate on prior conventional CTA or MRA examinations. Three experienced neuroradiologists independently reviewed the lesions using HR-MRA and PD-MRA with reconstructed voxel sizes of 0.25³ mm³ or 0.2³ mm³, respectively. A neurointerventionist established the gold standard with digital subtraction angiography. We compared the performance of HR-MRA, PD-MRA (0.25³-mm³ voxel), and PD-MRA (0.2³-mm³ voxel) in diagnosing aneurysms, both per lesion and per patient. The Fleiss kappa statistic was used to calculate inter-reader agreement. Results: The study involved 109 patients (average age 57.4 ± 11.0 years; male:female ratio, 11:98) with 141 indeterminate lesions. Of these, 78 lesions (55.3%) in 69 patients were confirmed as aneurysms by the reference standard. PD-MRA (0.25³-mm³ voxel) exhibited significantly higher per-lesion diagnostic performance compared to HR-MRA across all three readers: sensitivity ranged from 87.2%-91.0% versus 66.7%-70.5%; specificity from 93.7%-96.8% versus 58.7%-68.3%; and accuracy from 90.8%-92.9% versus 63.8%-69.5% (P ≤ 0.003). Furthermore, PD-MRA (0.25³-mm³ voxel) demonstrated significantly superior per-patient specificity and accuracy compared to HR-MRA across all evaluators (P ≤ 0.013). The diagnostic accuracy of PD-MRA (0.2³-mm³ voxel) surpassed that of HR-MRA and was comparable to PD-MRA (0.25³-mm³ voxel). The kappa values for inter-reader agreements were significantly higher in PD-MRA (0.820-0.938) than in HR-MRA (0.447-0.510). Conclusion: PD-MRA outperformed HR-MRA in diagnostic accuracy and demonstrated almost perfect inter-reader consistency in identifying intracranial aneurysms among patients with lesions initially indeterminate on CTA or MRA.

• 대한영상의학회지
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• 제85권2호
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• pp.258-269
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• 2024

관상동맥병 환자의 치료에 풍선팽창스텐트 치료는 현재 가장 흔히 시행되는 관상동맥재개통 치료법이다. 그러나 경피적 관상동맥 중재술 이후 재협착은 여전히 주요 합병증으로 남아 있다. 스텐트 재협착을 진단하기 위한 도구로서 관상동맥 CT 조영술(coronary CT angiography; 이하 CCTA)는 과거에는 주로 번짐허상과 움직임허상으로 인해 내강을 정확히 판단하기 어려워 그 역할이 제한적이었다. 따라서 정확한 확인을 위해서 침습적인 고식적 관상동맥 조영술로 넘어가는 경우가 많았다. 그러나 근래 CT 기술의 발달로 민감도와 특이도가 모두 개선되면서 그 역할이 중요해지고 있으며, 특히 일관되게 음성예측도가 높게 보고되고 있다. 본 종설에서는 CCTA를 이용한 관상동맥 스텐트 재협착 진단의 과거와 현재, 그리고 최신 동향에 대해 알아보고자 한다.

• Korean Journal of Radiology
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• 제23권2호
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• pp.256-263
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• 2022

Objective: This study aimed to evaluate the image quality and dose reduction of low-dose three-dimensional (3D) rotational angiography (RA) for evaluating intracranial aneurysms. Materials and Methods: We retrospectively evaluated the clinical data and 3D RA datasets obtained from 146 prospectively registered patients (male:female, 46:100; median age, 58 years; range, 19-81 years). The subjective image quality of 79 examinations obtained from a conventional method and 67 examinations obtained from a low-dose (5-seconds and 0.10-μGy/frame) method was assessed by two neurointerventionists using a 3-point scale for four evaluation criteria. The total image quality score was then obtained as the average of the four scores. The image quality scores were compared between the two methods using a noninferiority statistical testing, with a margin of -0.2 (i.e., score of low-dose group - score of conventional group). For the evaluation of dose reduction, dose-area product (DAP) and air kerma (AK) were analyzed and compared between the two groups. Results: The mean total image quality score ± standard deviation of the 3D RA was 2.97 ± 0.17 by reader 1 and 2.95 ± 0.20 by reader 2 for conventional group and 2.92 ± 0.30 and 2.95 ± 0.22, respectively, for low-dose group. The image quality of the 3D RA in the low-dose group was not inferior to that of the conventional group according to the total image quality score as well as individual scores for the four criteria in both readers. The mean DAP and AK per rotation were 5.87 Gy-cm² and 0.56 Gy, respectively, in the conventional group, and 1.32 Gy-cm² (p < 0.001) and 0.17 Gy (p < 0.001), respectively, in the low-dose group. Conclusion: Low-dose 3D RA was not inferior in image quality and reduced the radiation dose by 70%-77% compared to the conventional 3D RA in evaluating intracranial aneurysms.

• Investigative Magnetic Resonance Imaging
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• 제1권1호
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• pp.75-78
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• 1997

인체의 하지 MR Angiography(MRA)를 위한 하지전용 dual birdcage RF 코일을 설계, 제작하였으며 Volunteer실험을 하여 그 유용성을 보였다. 제안된 코일은 인체의 하지 전체의 영상을 위한 코일로 허벅지로부터 종아리까지 전체를 두 번의 영상을 통해 cover하게 된다. 기존의 방식대로 한 개의 코일을 옮기며 두 번 촬영할 경우 코일을 도중에 옮기게 외어 다리를 움직일 수밖에 없어 두 set의 영상이 완전히 연결이 되지 않지만 제안된 코일의 경우 침대만 움직이게 되므로 이런 문제가 없게 된다. 제안된 코일의 성능은 Volunteer의 하지 MRI 및 MRA를 얻어 확인했으며 임상적으로 매우 유용한 것으로 확인되었다.