• Title/Summary/Keyword: TOF angiography

Search Result 49, Processing Time 0.039 seconds

Dilatation of Superior Ophthalmic Vein and Visual Disturbance by Central Venous Stenosis: A Case Mimicking Cavernous Sinus Dural Arteriovenous Fistula (상안정맥 확장 및 시력 저하를 보인 중심정맥협착: 해면경막 동정맥루로 오인된 증례 보고)

  • Young Hun Jeon;Kyung Sik Yi;Chi Hoon Choi;Yook Kim;Yeong Tae Park
    • Journal of the Korean Society of Radiology
    • /
    • v.82 no.6
    • /
    • pp.1619-1627
    • /
    • 2021
  • Central venous stenosis is a relatively common complication in hemodialysis patients; however, jugular venous reflux (JVR) and increased intracranial pressure are rare, and associated progressive visual disturbance was reported in only a few cases. Here, we report a case of JVR with visual disturbance and increased intracranial pressure. Notably, the MRI was accompanied by a dilatation of the superior ophthalmic vein, which was mistaken for a cavernous sinus dural arteriovenous fistula (CSdAVF). The patient had JVR on time-of-flight MR angiography (TOF-MRA) and severe stenosis of the left brachiocephalic vein on conventional angiography. After balloon angioplasty for central venous stenosis, he was discharged after improvement of his visual disturbance. Although JVR due to central venous stenosis and CSdAVF might show similar symptoms, treatment plans are different. Therefore, it is important to distinguish radiologically based on a thorough review of MRI and TOF-MRA and confirm the central venous stenosis on cerebral angiography for the accurate diagnosis.

Evaluate the Possibility of MT Pulse at 3T CE-TOF-MRA in Patients with Cerebral Infarction (뇌경색 환자의 3Tesla CE-TOF-MRA에서 MT 펄스의 유용성)

  • Bae, Sung-Jin
    • Journal of radiological science and technology
    • /
    • v.30 no.3
    • /
    • pp.265-270
    • /
    • 2007
  • The purpose of this study was to evaluate the possibility of utilizing MT pulse at CE-TOF-MRA in patients with cerebral infarction. MRA using time-of-flight(TOF) technique with varying offset frequencies (0, 600, 1,200, and 1,800 Hz) magnetization transfer were performed in 10 patients with cerebral infarction at 3.0T MR scanner. CE-TOF-MRA and TOF-SPGR in normal vessel shown decreased SNR and increased CNR. The highest CNR in narrowing vessel shown at CE-TOF-MRA using 600 and 1,200 Hz offset frequencies. CNR in stenosis vessel increased dependent on using offset frequencies. The occlusion was clearly shown, and the highest CNR in occlusion shown at CE-TOF-MRA using 1,800 Hz offset frequencies. There was no shape variation in narrowing vessel or no visualizing vessel.

  • PDF

An Experimental Study on the Cause of Signal Inhomogeneity for Magnetic Resonance Angiography Using Phantom Model of Anterior Communicating(A-com) Artery (전교통동맥 모형을 이용한 자기공명혈관촬영술의 신호 불균일에 관한 실험적 연구)

  • Yoo, Beong-Gyu;Chung, Tae-Sub
    • Journal of radiological science and technology
    • /
    • v.25 no.1
    • /
    • pp.55-62
    • /
    • 2002
  • Aneurysm-mimicking findings were frequently visualized due to hemodynamical causes of dephasing effects around area of A-com artery during magnetic resonance angiography(MRA) and these kind of phenomena have not been clearly known yet. We investigated the hemodynamical patterns of dephasing effect around area of the A-com artery that might be a cause of false intracranial aneurysms on MRA. For experimental study, We used hand-made silicon phantoms of the asymmetric A-com artery as like a bifurcation configuration. In a closed circulatory system with UHDC computer driven cardiac pump system. MRA and fast digital subfraction angiography(DSA) involved the use of these phantoms. Flow patterns were evaluated with axial and coronal imaging of MRA(2D-TOF, 3D-TOF) and DSA of Phantoms constructed from an automated closed-type circulatory system filled with glycerol solution [circulation fluid(glycerol:water = 1:1.4)]. These findings were then compared with those obtained from computational fluid dynamic(CFD) for inter-experimental correlation study. Imaging findings of MRA, DSA and CFD on inflow zone according to the following: a) MRA demonstrated high signal intensity zone as inflow zone on silicon phantom; b) Patterns of DSA were well matched with MRA on trajectory of inflow zone; and c) CFD were well matched with MRA on the pattern of main flow. Imaging findings of MRA. DSA and CFD on turbulent flow zone according to the following: a) MRA demonstrated hyposignal intensity zone at shoulder and axillar zone of main inflow; b) DSA delineated prominent vortex flow at the same area. The hemodynamical causes of signal defect, which could Induce the false aneurysm on MRA, turned out to be dephasing effects at axilla area of bifurcation from turbulent flow as the results of MRA, DSA and CFD.

  • PDF

The 2D/3D Time-of-Flight, Phase Contrast and Contrast Enhanced Magnetic Resonance Angiograph (2D/3D Time-of-Flight, Phase Contrast 그리고 Contrast Enhanced 자기 공명 혈관조영기법에 관한 연구)

  • Yi, Yun;Choi, Jung-Hwan;Park, Seung-Hun;Kim, Si-Seung;Chung, Sung-Taek
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.40 no.4
    • /
    • pp.291-298
    • /
    • 2003
  • It is important to visualize a lesion accurately in diagnosis of disease. Many diseases result in a change of lesion. Magnetic resonance angiography can visualize the morphological characteristics of blood vessel. The magnetic resonance angiography (MRA) can be categorized to time-of-flight, phase contrast, and contrast enhanced MRA. In this paper, we introduce a principle, sequence, and feature of angiography For better image quality we describe data processing methods and show several applications to human bodies

Usefulness estimating of Time of flight(TOF) during Carotid angio inspection including Aortic arch (Aortic arch를 포함한 Carotid angio 검사 시 Time of flight(TOF)의 유용성 평가)

  • Yoo, Yeong-Jun
    • Korean Journal of Digital Imaging in Medicine
    • /
    • v.15 no.1
    • /
    • pp.1-7
    • /
    • 2013
  • Purpose : The Carotid Angio inspection including Aortic arch applied to wide area is conducted as the Contrast Enhance MR Angiography(CEA) which is using a contrast medium. However it is a burden not only for someone such as infants, pregnant women and patients suffering from kidney failure but continuous use of contrast medium also can be a burden for patients who has been taken follow up inspection since diagnose lesion already. The purpose of this study is to estimate a usefulness of the Time of Flight (TOF) by comparing with CEA. Materials and methods : 10 patients with an average age of 58 (from 45 to 75) who had MRA inspection in our hospital were studied using 3.0 Tesla Aachieva (Philips, Netherland) MRI system and Sense Neuro-Vascular 16 Channels Coil. The same patient was inspected both TOF and CEA simultaneously. The TOF inspection included from Aortic arch to Willis Circle by connecting 3 TOF stacks and so did CEA inspection. The quantitative analysis was conducted through signal to noise ratio(SNR) and contrast to noise ratio(CNR) with soft tissue by setting up an area of interest on CCA bifurcatoin, ICA, ECA, MCA and VA concerning obtained image. In case of qualitative analysis, 3 radiological technologists and 1 radiologist evaluated 4 items (1: Visibility of the blood vessel, 2: Image distortion measure, 3: Overlapping measure with vein, 4: Peripheral blood vessel description measure) into five points scale (1: Very bad, 2: Bad, 3: Normal 4: Good, 5: Very good). Results : Results for the quantitative analysis was obtained by calculating the average of 5 ROIs in case of SNR and CNR separately. Results of SNR, TOF were generally measured higher than CEA (In case of TOF were 166.1, 205.2, 154.39, 172.23, 161.95, and CEA were 92.05, 95.43, 84.76, 73.69, 88.3). But according to the result of CNR, both TOF and CEA were measured similarly as 67.62, 106.71, 55.9, 73.74, 63.46 for TOF and 67.82, 71.19, 60.52, 49.45, 64.07 for CEA. Throughout every results of each ROI, SNR showed statistically meaningful consequence (0.050.05). In case of qualitative analysis the average of each evaluated item was 4.2points and 4.28points in the item1, 2.93points and 4.55points in the item2, 4.6points and 3.13points in the item3, 2.88points and 4.6points in the item4. According to the results TOF was measured higher in the item3 while in the item2 and item4 CEA was higher and in case of the item1, both CEA and TOF were similar. To sum up statistically meaningful results (p<0.05) were shown in the item2, item3 and item4 but not in the item1 (p>0.05). Conclusions : Both TOF and CEA are complementary because each inspection has pros and cons, but when inspect wide area including Aortic arch normally CEA is conducted. But TOF inspection also can be considered as alternative in terms of patients who has difficulty in the contrast medium such as infants, pregnant women and patients suffering from kidney failure and patients during follow up.

  • PDF

Carotid Intraplaque Hemorrhage Imaging: Diagnostic Value of High Signal Intensity Time-of-Flight MR Angiography Compared with Magnetization-Prepared Rapid Acquisition with Gradient-Echo Sequencing

  • Ahn, Ji-eun;Kwak, Hyo Sung;Chung, Gyung Ho;Hwang, Seung Bae
    • Investigative Magnetic Resonance Imaging
    • /
    • v.22 no.2
    • /
    • pp.94-101
    • /
    • 2018
  • Purpose: To determine the value of the appearance of the high signal intensity halo sign for detecting carotid intraplaque hemorrhage (IPH) on maximum intensity projection (MIP) of time-of-flight (TOF) MR angiography (MRA), based on high signal intensity on magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) sequencing. Materials and Methods: A total of 78 carotid arteries in 65 patients with magnetization-prepared rapid acquisition gradient-echo (MPRAGE) positive on carotid plaque MR imaging were included in this study. High-resolution MR imaging was performed on a 3.0-T scanner prior to carotid endarterectomy or carotid artery stenting. Fast spin-echo T1- and T2-weighted axial imaging, TOF, and MPRAGE sequences were obtained. Carotid plaques with high signal intensity on MPRAGE > 200% that of adjacent muscle on at least two consecutive slices were defined as showing IPH. Halo sign of high signal intensity around the carotid artery was found on MIP from TOF MRA. Continuous and categorical variables were compared among groups using the Mann-Whitney test and Fisher's exact tests. Results: Of these 78 carotid arteries, 53 appeared as a halo sign on the TOF MRA. The total IPH volume of patients with a positive halo sign was significantly higher than that of patients without a halo sign ($75.0{\pm}86.8$ vs. $16.3{\pm}18.2$, P = 0.001). The maximum IPH axial wall area in patients with a positive halo sign was significantly higher than that of patients without a halo sign ($11.3{\pm}9.9$ vs. $3.7{\pm}3.6$, P = 0.000). Conclusion: High signal intensity halo of IPH on MIP of TOF MRA is associated with total volume and maximal axial wall area of IPH.

Usefulness of Silent MRA for Evaluation of Aneurysm after Stent-Assisted Coil Embolization

  • You Na Kim;Jin Wook Choi;Yong Cheol Lim;Jihye Song;Ji Hyun Park;Woo Sang Jung
    • Korean Journal of Radiology
    • /
    • v.23 no.2
    • /
    • pp.246-255
    • /
    • 2022
  • Objective: To determine the usefulness of Silent MR angiography (MRA) for evaluating intracranial aneurysms treated with stent-assisted coil embolization. Materials and Methods: Ninety-nine patients (101 aneurysms) treated with stent-assisted coil embolization (Neuroform atlas, 71 cases; Enterprise, 17; LVIS Jr, 9; and Solitaire AB, 4 cases) underwent time-of-flight (TOF) MRA and Silent MRA in the same session using a 3T MRI system within 24 hours of embolization. Two radiologists independently interpreted both MRA images retrospectively and rated the image quality using a 5-point Likert scale. The image quality and diagnostic accuracy of the two modalities in the detection of aneurysm occlusion were further compared based on the stent design and the site of aneurysm. Results: The average image quality scores of the Silent MRA and TOF MRA were 4.38 ± 0.83 and 2.78 ± 1.04, respectively (p < 0.001), with an almost perfect interobserver agreement. Silent MRA had a significantly higher image quality score than TOF MRA at the distal internal carotid artery (n = 57, 4.25 ± 0.91 vs. 3.05 ± 1.16, p < 0.001), middle cerebral artery (n = 21, 4.57 ± 0.75 vs. 2.19 ± 0.68, p < 0.001), anterior cerebral artery (n = 13, 4.54 ± 0.66 vs. 2.46 ± 0.66, p < 0.001), and posterior circulation artery (n = 10, 4.50 ± 0.71 vs. 2.90 ± 0.74, p = 0.013). Silent MRA had superior image quality score to TOF MRA in the stented arteries when using Neuroform atlas (4.66 ± 0.53 vs. 3.21 ± 0.84, p < 0.001), Enterprise (3.29 ± 1.59 vs. 1.59 ± 0.51, p = 0.003), LVIS Jr (4.33 ± 1.89 vs. 1.89 ± 0.78, p = 0.033), and Solitaire AB stents (4.00 ± 2.25 vs. 2.25 ± 0.96, p = 0.356). The interpretation of the status of aneurysm occlusion exhibited significantly higher sensitivity with Silent MRA than with TOF MRA when using the Neuroform Atlas stent (96.4% vs. 14.3%, respectively, p < 0.001) and LVIS Jr stent (100% vs. 20%, respectively, p = 0.046). Conclusion: Silent MRA can be useful to evaluate aneurysms treated with stent-assisted coil embolization, regardless of the aneurysm location and type of stent used.