• 대한방사선기술학회지:방사선기술과학
• /
• 제45권4호
• /
• pp.313-320
• /
• 2022

Both angiography and interventional procedures accompanied by angiography provide many diagnostic and therapeutic benefits to patients and are rapidly increasing. However, unlike general radiography or computed tomography using the same X-ray, the amount of radiation is quite high, but the dose range can vary considerably for each patient and operator. The high sensitivity of the lens to radiation during cerebral angiography and neurointervention is already well known, and although there are many related studies, it is insufficient to easily reduce radiation in diagnosis and treatment. In this situation, in particular, by adding three-dimensional rotational angiography (3D-RA) to the existing two-dimensional (2D) angiography, it is now possible to make an accurate diagnosis. However, since this 3D-RA acquires images through projection of more radiation than before, the exposure dose of the lens may be higher. Therefore, we tried to analyze whether the radiation dose of the lens can be reduced by moving the lens out of the field range by adjusting the table height and magnification ratio during the examination using 3D-RA. The surface dose was measured using a rando phantom and a radiophotoluminescent glass dosimeter (PLD) and the radiation dose was compared by adjusting the table height and magnification ratio based on the central point. As a result, it was found that the radiation dose of the lens decreased as the table height increased from the central point, that is, as the lens was out of the field of view. In conclusion, in 3D-RA, moving the table position of about 2 cm in height will make a significant contribution to the dose reduction of the lens, and it was confirmed that adjusting the magnification ratio can also reduce the surface dose of the lens.

• Journal of Korean Neurosurgical Society
• /
• 제44권5호
• /
• pp.338-340
• /
• 2008

A rare case of ruptured aneurysm associated with multiple $A_1$ fenestrations resembling plexiform network was demonstrated by 3D angiography. A 56-year-old female presented with a ruptured aneurysm in the $A_2$ segment of the left distal anterior cerebral artery associated with the right $A_1$ fenestration. The ruptured aneurysm was occluded with surgical neck clipping via interhemispheric approach without neurological deficit. Plexiform fenestrations of the right distal $A_1$. opposite side to the left ruptured $A_2$ aneurysm, were clearly visible on postoperative 3D angiography. Our case may strongly support the theory described by Paget, namely that a remnant of the plexiform anastomosis between the primitive olfactory artery and $A_1$ segment is the source of such fenestration.

• Clinical and Experimental Pediatrics
• /
• 제59권3호
• /
• pp.149-152
• /
• 2016

We report a case of a 5-year-old girl who developed left hemiparesis and left facial palsy, 6 days after the initiation of fever and respiratory symptoms due to pneumonia. Chest radiography, conducted upon admission, showed pneumonic infiltration and pleural effusion in the left lung field. Brain magnetic resonance imaging showed acute ischemic infarction in the right middle cerebral artery territory. Brain magnetic resonance angiography and transfemoral cerebral angiography revealed complete occlusion of the right middle cerebral artery. Mycoplasma pneumoniae infection was identified by a 4-fold increase in IgG antibodies to M. pneumoniae between acute and convalescent sera by enzyme-linked immunosorbent assay. Fibrinogen and D-dimer levels were elevated, while laboratory exams in order to identify other predisposing factors of pediatric stroke were all negative. This is the first reported pediatric case in English literature of a M. pneumoniae-associated cerebral infarction involving complete occlusion of the right middle cerebral artery.

• Journal of Korean Neurosurgical Society
• /
• 제42권2호
• /
• pp.103-111
• /
• 2007

Objective : We evaluated the accuracy of multislice computerized tomographic angiography (MCTA) in the postoperative evaluation of clipped aneurysms by comparising it with three dimensional digital subtraction angiography (3D-DSA). Methods : Between May 2004 and September 2006, we included patients with ruptured cerebral aneurysm of the anterior circulation that was surgically clipped and evaluated by both postoperative MCTA and postoperative 3D-DSA. We measured the diagnostic performance and calculated the sensitivity and specificity of postoperative MCTA compared to 3D-DSA in the detection of aneurysm remnants. Results : A total of 11 neck remnants among the 92 clipped aneurysms (11.9%) were confirmed by 3D-DSA. According to Sindou's classification of aneurysm remnants, 8.7% of clipped aneurysms (8/92) had only neck remnant on 3D-DSA and 3.2% (3/92 aneurysms) had residuum of the neck and sac on 3D-DSA. There were 12 (13.04%) equivocal cases that were difficult to interpret based on the postoperative MCTA. The reasons for the equivocal cases included multiple clips (6 cases, 50.0%). beam-hardening effect (4 cases, 33.3%), motion artifact (1 case, 8.3%), fenestrated clip (1 case, 8.3%) and other combined causes. The sensitivity and specificity of the postoperative MCTA was 81.8% and 88.9%, respectively by ROC curve (p=0.000). Conclusion : MCTA is an accurate noninvasive imaging method used for the assessment of clipped aneurysms in the anterior circulation. If the image quality of postoperative MCTA is good quality and the patient has been treated with a single titanium clip, except a fenestrated clip, the absence of an aneurysm remnant can be diagnosed by MCTA alone and the need for postoperative DSA can be reduced in a large percentage of cases.

• Journal of Korean Neurosurgical Society
• /
• 제30권6호
• /
• pp.711-716
• /
• 2001

Objectives : Three-dimensional computed tomographic angiography(3D-CTA) is recently developed diagnostic imaging modality. We have studied this noninvasive method for possible role in replacing conventional angiography( CA) in the detection of aneurysms of the circle of Willis in patients with subarachnoid hemorrahge(SAH). Methods : We studied retrospectively, the 100 patients with SAH or unruptured aneurysms admitted to our hospital from October 1997 to December 1998. Among there, 85 patients underwent CTA, 82 patients underwent CA and 67 patients underwent both of CTA and CA. 3D-CTA was obtained using maximum intensity projection(MIP) and shaded-surface display(SSD) reconstruction. Results : Total 107 aneurysms were detected in 92 patients, and 64 aneurysms were detected in 67 patients underwent both CTA and CA. In five cases of those 67 cases, aneurysms were detected by CA but not by 3D-CTA. The detection rate of aneurysms(91.8%) and the detection rate of parent artery in cases of anterior communicating artery aneurysms(86.9%) with total 3D-CTA were relatively compatible with that of CA. But 3D-CTA was not enough in detection of posterior communicating artery aneurysms, internal carotid artery aneurysms as well as small sized aneurysm(<3mm). Conclusion : We consider CTA is valuable in as a screening test for cerebral aneurysm and follow-up test. And it is also valuable in early surgery for patients with aneurysmal rebleeding because of simple, quick, non-invasive method.

• 한국방사선학회논문지
• /
• 제17권3호
• /
• pp.335-341
• /
• 2023

본 연구는 뇌혈관조영검사에서 뇌동맥자루 영상을 4개의 알고리즘(Standard, Bone, Dual volume, Stent Follow up)에 3D로 재구성하여 Noise, SNR, CNR 측정값을 분석한 후 최적의 알고리즘을 알아보고자 하였다. 분석방법으로는 4개의 알고리즘으로 재구성한 영상에 Image J 프로그램을 이용하여 이미지 분석과 영역 및 픽셀 값을 계산하였다. Noise, SNR, CNR은 측정부위를 영상에서 비정상혈관(동맥자루)이 있는 지점과 주위에 있는 정상혈관을 지정하여 관심영역(Region of interest)을 측정하고 평균값과 표준편차를 구하였다. 배경잡음(Background)은 신뢰성을 높이기 위해 주위에 있는 정상혈관 2군데로 하였다. SNR과 CNR의 값은 주어진 식에 의거하여 산출하였다. 결과적으로 Stent follow up 알고리즘에서 노이즈가 가장 낮게 SNR, CNR은 가장 높게 나타났다. 따라서 Stent follow up 알고리즘이 가장 적절한 알고리즘으로 판단된다. 이 연구의 자료가 뇌혈관조영검사에서 혈관계, 동맥자루 3D 영상 평가하는 기초자료로 사용되기를 바라며 다양한 알고리즘 변화로 영상의 질을 더 높일 수 있는 계기가 될 것으로 판단된다.

• 한국방사선학회논문지
• /
• 제13권7호
• /
• pp.961-968
• /
• 2019

본 연구는 CT를 이용한 뇌혈관 추출 검사에서 이중에너지 기법을 활용하여 각 에너지 준위별 뇌혈관 조영술의 유용성을 평가하였다. 방법은 CT 뇌혈관 조영술을 시행한 환자 15명의 DE 영상과 SE 영상을 대상으로 하였다. 영상의 분석은 MCA, 뇌실직 조직, Background에 ROI를 설정하여 평균값, 표준편차 및 SNR, CNR 값을 구하고, SE영상과 비슷하게 구현되는 에너지 영역을 알아보았다. Likert 5점 척도 육안평가를 병행한 결과 DE 40 keV와 SE 120 kVp에서 가장 선명한 MCA 영상을 확인 하였다(p>0.05). SE영상의 SNR 값은 DE영상의 40 keV에너지 준위값과 비슷하게 측정되었고, 40 keV와 50 keV의 저에너지 준위의 영상이 SNR이 높게 측정되어 고에너지 준위의 영상에 비해 대조도가 높아 뇌혈관질환을 유용하게 관찰할 수 있을 것으로 사료된다.

• Journal of Korean Neurosurgical Society
• /
• 제60권5호
• /
• pp.504-510
• /
• 2017

Objective : To investigate the morphological and hemodynamic parameters associated with middle cerebral artery (MCA) bifurcation aneurysm rupture. Methods : A retrospective study of 67 consecutive patients was carried out based on 3D digital subtraction angiography data. Morphological and hemodynamic parameters including aneurysm size parameters (dome width, height, and perpendicular height), longest dimension from the aneurysm neck to the dome tip, neck width, aneurysm area, aspect ratio, Longest dimension from the aneurysm neck to the dome tip (Dmax) to dome width, and height-width, Bottleneck factor, as well as wall shear stress (WSS), low WSS area (LSA), percentage of LSA (LSA%) and energy loss (EL) were estimated. Parameters between ruptured and un-ruptured groups were analyzed. Receiver operating characteristics were generated to check prediction performance of all significant variables. Results : Sixty-seven patients with MCA bifurcation aneurysm were included (31 unruptured, 36 ruptured). Dmax (p=0.008) was greater in ruptured group than that in un-ruptured group. D/W (p<0.001) and the percentage of the low WSS area ($0.09{\pm}0.13$ vs. $0.01{\pm}0.03$, p<0.001) were also greater in the ruptured group. Moreover, the EL in ruptured group was higher than that in unruptured group ($6.39{\pm}5.04$ vs. $1.53{\pm}0.86$, p<0.001). Multivariate regression analysis suggested D/W and EL were significant predictors of rupture of MCA bifurcation aneurysms. Correlation analyses revealed the D/W value was positively associated with the EL (R=0.442, p<0.01). Conclusion : D/W and EL might be the most two favorable factors to predict rupture risk of MCA bifurcation aneurysms.

• Journal of Korean Neurosurgical Society
• /
• 제41권4호
• /
• pp.230-235
• /
• 2007

Objective : We investigated the incidence of the vascular abnormalities associated with spontaneous intracerebral hemorrhage [ICH] using three-dimensional computed tomographic angiography [3D-CTA]. Methods : We prospectively assessed consecutive 76 patients with spontaneous intracerebral hemorrhage [ICH] who underwent 3D-CTA between June 2003 and May 2005. The patients with a recent history of trauma or mainly subarachnoid hemorrhage were excluded. We investigated relationship between vascular abnormality and ICH location. The findings of 3D-CTA were classified as one of three patterns with ICH; type A [without evidence of vascular abnormality], type B [with no vascular abnormality as the source of hemorrhage, but with incidental vascular abnormality], and type C [presence of a vascular abnormality as the source of hemorrhage]. Results : Sites of ICH were lobar 26, basal ganglia 23, thalamus 17, posterior fossa 6 and dominant intraventricular hemorrhage [IVH] 4. Among 76 patients, sixteen [21.1%] vascular abnormalities were noted excluding 13 cases of stenoocclusive disease. Sixteen cases included 6 cases of cerebral aneurysms [7.9%], 5 moyamoya diseases [6.6%], 4 arteriovenous malformations [5.3%] and 1 dural sinus thrombosis [1.3%]. Lobar ICH [30.8%] had a higher vascular abnormalities than other types, and younger age [<40] group had a higher incidence of vascular abnormalities than old age group. The patterns of 3D-CTA include sixty cases [79.0%] of type A, 6 cases [7.8%] of type Band 10 cases [13.2%] of type C. The vascular abnormalities were found in 8 [13.5%] of 59 hypertensive patients and 8 [47.0%] of 17 non-hypertensive patients [p=0.006]. Conclusion : 3D-CT angiography is considered a useful screening tool for ICH patients with suspected cerebrovascular abnormalities and should be considered in such clinical settings, especially in lobar type and in non-hypertensive younger patients.

• Korean Journal of Radiology
• /
• 제24권7호
• /
• pp.681-689
• /
• 2023

Objective: Three-dimensional rotational angiography (3D-RA) is increasingly used for the evaluation of intracranial aneurysms (IAs); however, radiation exposure to the lens is a concern. We investigated the effect of head off-centering by adjusting table height on the lens dose during 3D-RA and its feasibility in patient examination. Materials and Methods: The effect of head off-centering during 3D-RA on the lens radiation dose at various table heights was investigated using a RANDO head phantom (Alderson Research Labs). We prospectively enrolled 20 patients (58.0 ± 9.4 years) with IAs who were scheduled to undergo bilateral 3D-RA. In all patients' 3D-RA, the lens dose-reduction protocol involving elevation of the examination table was applied to one internal carotid artery, and the conventional protocol was applied to the other. The lens dose was measured using photoluminescent glass dosimeters (GD-352M, AGC Techno Glass Co., LTD), and radiation dose metrics were compared between the two protocols. Image quality was quantitatively analyzed using source images for image noise, signal-to-noise ratio, and contrast-to-noise ratio. Additionally, three reviewers qualitatively assessed the image quality using a five-point Likert scale. Results: The phantom study showed that the lens dose was reduced by an average of 38% per 1 cm increase in table height. In the patient study, the dose-reduction protocol (elevating the table height by an average of 2.3 cm) led to an 83% reduction in the median dose from 4.65 mGy to 0.79 mGy (P < 0.001). There were no significant differences between dose-reduction and conventional protocols in the kerma area product (7.34 vs. 7.40 Gy·cm², P = 0.892), air kerma (75.7 vs. 75.1 mGy, P = 0.872), and image quality. Conclusion: The lens radiation dose was significantly affected by table height adjustment during 3D-RA. Intentional head off-centering by elevation of the table is a simple and effective way to reduce the lens dose in clinical practice.