• Investigative Magnetic Resonance Imaging
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• v.22 no.4
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• pp.266-271
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• 2018

A 66-year-old woman was referred for treatment of incidental detection of two intracranial aneurysms. Time-of-flight MR angiography (TOF MRA) revealed two aneurysms at the M1 segment of the right middle cerebral artery, and clinoid segment of left internal carotid artery, respectively. On digital subtraction angiography, there was a saccular aneurysm on the left internal carotid artery, but the other aneurysm was not detected on the right middle cerebral artery. Based on comprehensive review of imaging findings, organized thrombosed aneurysm was judged as the most likely diagnosis. In the presented report, magnetization transfer (MT) pulse to TOF MRA was used, to differentiate aneurysm-mimicking lesion on TOF MRA. We report that MT technique could be effective in differentiating true aneurysm, from possible T1 high signal artifact on TOF MRA.

• Journal of radiological science and technology
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• v.24 no.2
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• pp.23-28
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• 2001

The purpose of this study is to compare the 3-dimensional MR angiography(MRA) with digital subtraction angiography(DSA) for the evaluation of pedal artery. MR angiography was performed using three-dimensional FISP acquisition before, and four sequential acquisitions after the injection of gadolinium(0.2 mmol/kg, 3 ml/sec). MRA was compared with DSA for a correct identification of the arterial segment. Out of 168 segments, 32 segmints were invisible in both MRA and DSA. At the level of ankle, 48 segments were visible in both examinations, and 18 segments were visible only in MRA. In the foot area, 34 segments were visible in MRA, but not in DSA. Three arterial segments were visible only in DSA. 3D MRA is comparable to DSA for the evaluation of pedal artery, thus it gives additional Information for the planning of treatment in lower extremity artery.

• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.33-38
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• 2007

Purpose : To investigate the applicability of the new three-dimensional overlapped reconstruction MR angiography (3-D ORMRA) technique in patients with hemifacial spasm and to compare the new 3-D reconstruction images with conventional MRA source images. Materials and Methods : The study group comprised 27 patients with surgically proven hemifacial spasm. In all patients, conventional MRA source images and 3-D fast imaging employing steady-state acquisition (FIESTA) images were obtained prospectively. After 3-D MR angiographic images were obtained, the 3-D MRA and FIESTA images were overlapped at the workstation by using GE A/W 4.2 add/sub software. We analyzed the relationship between the offending vessels and root exit zone of the facial nerve using both 3-D ORMRA images and conventional MRA source images. Results : In 25 of 27 patients, the offending vessel at the REZ of the facial nerve could be correctly identified on conventional MRA source images. In all patients, the presumed offending vessels depicted by the overlapped 3-D reconstruction MRA image corresponded well with the intraoperative findings. The 3-D reconstruction image showed more clear visualization of the spatial relationship between the offending vessels and the root exit zone of the facial nerve. Conclusion : The overlapped 3-D reconstruction MR angiography technique is very useful and informative in patients with hemifacial spasm, as compared with conventional MRA angiography technique.

• Proceedings of the KSMRM Conference
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• 1997.10a
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• pp.28-28
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• 1997

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.75-78
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• 1997

A dual birdcage RF coil is proposed for MRI and MRA of the human leg. The proposed coil c can be used to cover the whole human leg by imaging upper and lower parts of the leg separately. In the conventional leg imaging scheme using a single RF coil, the leg has to be r relocated when changing the position of the RF coil thus causing problems in matching the i images from two sets of coils. When using the proposed dual RF coil, however, only the bed h has to be moved to select the imaging region while only one part of the dual coil is used each t time by using current switching and PIN diodes. The utility of proposed coil has been verified b by volunteer MRI and MRA and the imaging results show that the coil is useful for the clinical MRI and MRA of the leg.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.215-221
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• 2010

To assess the clinical value of time resolved imaging of contrast kinetics(TRICKS) MRA by comparison with conventional time of flight(TOF) MR angiography. Both TOF-MRA and TRICKS-MRA were performed in 17 patients with cerebrovascular disease and in 6 patients with brain tumor. Among 17 cerebraovascular patients, digital subtraction angiography(DSA) data were also obtained in 11 patients. TOF-MRA showed good spatial resolution but short in temporal resolution. Although TRICKS-MRA showed somewhat low spatial resolution, it showed superior temporal resolution by distinguishing vessel and tumor in all patients. Also, from the analysis of vessel-tumor relationship, TRICKS-MRA showed better performance than TOF-MRA. TRICKS-MRA makes it possible to image arterial, capillary and venous phase sequentially with very speedy manner and therefore, the clinical use of this method is highly suggestive for future use.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1105-1110
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• 2009

To assess the clinical value of time resolved imaging of contrast kinetics(TRICKS) MRA by comparison with conventional time of flight(TOF) MR angiography. Both TOF-MRA and TRICKS-MRA were performed in 17 patients with cerebrovascular disease and in 6 patients with brain tumor. Among 17 cerebraovascular patients, digital subtraction angiography(DSA) data were also obtained in 11 patients. TOF-MRA showed good spatial resolution but short in temporal resolution. Although TRICKS-MRA showed somewhat low spatial resolution, it showed superior temporal resolution by distinguishing vessel and tumor in all patients. Also, from the analysis of vessel-tumor relationship, TRICKS-MRA showed better performance than TOF-MRA. TRICKS-MRA makes it possible to image arterial, capillary and venous phase sequentially with very speedy manner and therefore, the clinical use of this method is highly suggestive for future use.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.96-103
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• 1998

Purpose : To assess the clinical utility of turbo contrast-enhanced magnetic resonance angiography(CE MRA) in the evaluation of the aortic arch and its major branches and to compare the image quality of CE MRA among different coils used. Materials and Methods : Turbo three-phase dynamic CE MRA encompassing aortic arch and its major branches was prospectively performed after manual bolus IV injection of contrast material in 29 patients with suspected cerebrovascular diseases at 1.0T MR unit. the raw data were obtained with 3-D FISH sequence (TR 5.4ms, TE 2.3ms, flip angle 30, slab thickness 80nm, effective slice thickness 4.0mm, matrix size $100{\times}256$, FOV 280mm). Total data acquisition time was 4. to 60 seconds. We subjectively evaluated the imge quality with three-rating scheme : "good" for unequivocal normal finding, "fair" for relatively satisfactory quality to diagnose 'normal' despite intravascular low signal, and "poor" for equivocal diagnosis or non-visualization of the origin or segment of the vessels due to low signal or artifacts which needs catheter angiography. At the level of the carotid bifurcation, it was compared with conventional 2D-TOF MRA image. Overall image quality was also compared visually and quantitatively by measuring signal-to-noise ratios (SNRs) of the ascending aorta, the innominate artery and both common carotid arteries among the three different coils used(CP body array(n=12), CP neck array(n=9), and head-and-neck(n=8). Results : Demonstration of the aortic arch and its major branches was rated as "good" in 55% (16/29) and "fair" in 34%(10/29). At the level of the carotid bifurcation, image quality of turbo CE MRA was same as or better than conventional 2D-TOF MRA in 65% (17/26). Overall image quality and SNR were significantlygreater with CP body array coil than with CP neck array or head-and-neck coil. Conclusions : Turbo CE MRA can be used as a screening exam in the evaluation of the major branches of the aortic arch from their origin to the skull base. Overall imagequality appears to be better with CP body array coil than with CP neck array coil or head-and-neck coil.

• Journal of Magnetics
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• v.22 no.2
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• pp.234-237
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• 2017

This study is aimed to optimize a location of region of interest (ROI) in test bolus carotid contrast enhanced magnetic resonance angiography (CE-MRA) at 3.0T. A total of consecutive 270 patients with no cardiovascular and vessel diseases were selected. Patients underwent elliptical centric 3D CE-MRA with the test bolus technique to identify the individual arterial arrival time. Quantitative measurements were performed by drawing ROIs of $25mm^2$ and signal intensities (SI) were measured in the center of common carotid artery (CCA), internal carotid artery (ICA) and aortic arch (AA). As a result, ROIs located within AA showed a significantly clarified arterial peak and over three times increased SI, while no significant arterial peak time differences were observed compared to ROIs located within CCA. In conclusion, it was demonstrated that the aortic arch is the optimal position to locate ROI in test bolus images of the carotid CE-MRA.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.275-280
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• 2003

The method of simultaneous data acquisition of arteries and veins(SAAV) was suggested to obtain MR angiography of arteries and veins at 0.3T low filed MRI system (Magfinder, AlLab. Korea). Two separated artery- and vein-images were put together using AVCM(Artery-Vein Color Mapping) algorithm and presented in the same image. In this study, artery- and vein-separated angiograms of volunteer's neck were obtained. Two dimensioal blood-enhanced images wre sequentially obtained using SAAV pulse sequence based on time-of-flight(TOF) method with flow compensation. Imaging parameters were TR/TE=70/12msec. FOV=230mm, slice thickness = 3mm, flip angle=90$^{\circ}$, matrix size=256${\times}$256${\times}$64mm. TSat TH/SPA=15/20mm, Ts_v=10msec and Ts_a=40ms. 3D MRA images were reconstructed using the maximum intensity projection(MIP) and the artery-vein color mapping(AVCM) algorithm. This study showed good possibility of clinical applications of MRA in 0.3T which provides valuable diagnostic information of clinical vascular diseases.