• Korean Journal of Radiology
• /
• 제23권8호
• /
• pp.803-810
• /
• 2022

Objective: To investigate the clinical application of differential subsampling with Cartesian ordering (DISCO) contrast-enhanced (CE) magnetic resonance angiography for anterolateral thigh (ALT) flap transplantation, using operative findings as a reference. Materials and Methods: Thirty patients (21 males and nine females; mean age ± standard deviation, 45.5 ± 15.6 years) who were scheduled to undergo reconstruction with ALT flaps between June 2020 and June 2021 were included in the prospective study. Before ALT flap transplantation, patients were scanned using CE-DISCO imaging. All acquired DISCO images of the 60 lower limbs (both sides from each patient) were analyzed using maximum intensity projection and volume rendering methods. Two experienced radiologists were employed to examine the patterns of the lateral circumflex femoral artery (LCFA), its branches, and perforators and their skin termini, which were compared with the operative findings. Results: Using CE-DISCO, the patterns of the LCFA and its branches were clearly identified in all patients. Four different origins of the LCFA were found among the 60 blood vessels: type I (44/60, 73.3%), type II (6/60, 10.0%), type III (8/60, 13.3%), and type IV (2/60, 3.3%). Owing to a lack of perforators entering the skin, two patients did not undergo ALT flap transplantation. For the remaining 28 patients, the ALT flaps in 26 patients were successfully operated without flap reselection during the operation, while the remaining two patients underwent other surgical procedures due to the thin diameter of the perforator or injury of the perforator during the operation. The success rate of flap transplantation was 92.8% (26/28). All transplanted flaps exhibited good blood supply and achieved primary healing without infection or delayed healing. Conclusion: CE-DISCO imaging can be an effective method for preoperative perforator imaging before ALT flap transplantation.

• Journal of Korean Neurosurgical Society
• /
• 제30권sup1호
• /
• pp.44-50
• /
• 2001

Objectives : The objective of this study was to investigate the role of postoperative three dimensional short-range magnetic resonance angiography(3D-TOF MRA) in predicting the clinical outcomes following microvascular decompression(MVD) for the treatment of a hemifacial spasm(HFS). Material and Method : Postoperative magnetic resonance(MR) imaging was performed on 123 patients with a HFS between March 1999 and May 2000. All patients who had postoperative MR imaging were undertaken preoperative MR imaging. Of the 123 patients, 122 patients were included in this retrospective study. The degree of the detachment of vascular contact, and change of the position of offender were determined by pre- and postoperative 3D-TOF MRA. These findings were compared with the surgical findings and clinical outcomes. Results : Of 122 patients who had successful MVD, clear decompression of offenders of the root entry zone(REZ) of facial nerve was found in 106 patients(86.9%), partial decompression in 10 patients(8.2%) and contact of offenders to the REZ of facial nerve in 6 patients(4.9%) by the postoperative 3D-TOF MRA. Our patients demonstrated that the types of offender did not influence with the degree of decompression of REZ of facial nerve and with surgical outcomes(p>0.05). Also, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement of symptoms(p>0.05). Futhermore, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement time (p>0.05). Conclusion : Our data suggests that MVD of facial nerve alone may not be sufficient to resolve the symptoms in all patients with hemifacial spasm. Therefore, another unknown factors besides vascular compression may be involved to cause symptoms in certain patients and it may be necessary to remove these factors with MVD simultaneously to obtain the resolution of symptom.

• Investigative Magnetic Resonance Imaging
• /
• 제7권1호
• /
• pp.22-30
• /
• 2003

목적 : 본 연구에서는 호흡멈춤 K-space 분할 2D-FASTCARD 자기공명영상 기법에 의한 관상동맥우회로내의 혈류개방성 검사의 임상 적 유용성을 조사하였다. 대상 및 방법: 관상동맥우회로 시술을 한 38명의 환자에서 내유동맥의 수는 36개이었고 대복제정맥편은 56개였다. 2차원 FASTCARD 기법을 이용하여 sagittal과 transverse평면에서 13-18초 동안 호흡을 멈추고 영상을 심장박동주기에 맞추어 획득하였다. 신호크기-영상의 hard copy를 이용하여 관상동맥우회로가 예상되는 지점에서 혈류에 의한 작은 원형부분이 밝게 보이면 해당 graft가 개방되었다고 판독하였다. 결과: 시술 환자의 다양한 관상동맥우회술의 양상에 따라 분류하여 Sagittal평면과 transverse 평면에서 내유동맥편과 대복제정맥편의 개방성을 검사하였다 좌회선지관상동맥의 분지로 연결되는 대복제정맥편은 Sagittal평면에서, 좌전하행지 관상동맥 혹은 그의 분지나 우관상동맥으로 연결되는 내유동맥편 혹은 대복제정맥편은 transverse평면에서 최대 감도의 개방성 영상을 보였다. 전체 38명의 환자 중에 23명의 영상획득 가능환자에서 45개의 관상동맥우회로가 보였으며 9개가 보이지 않았다. 증상이 있던 두 명의 환자중 2개의 관상 동맥우회로가 보이지 않았다. 결론: 호흡멈춤 K-space 분할 2D-FASTCARD 자기공명영상 기법으로 관상동맥우회로의 혈류 개방성의 비침습적 평가가 가능하다. 그러나 이 방법으로 보이지 않는 관상동맥 우회로는 조영제를 사용한 자기공명 혈관조영술이나 일반 혈관조영술등의 방법으로 그 진위를 재검사하여 확진하는 것이 필요하다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제41권2호
• /
• pp.109-113
• /
• 2018

Despite the continuous development of software, it is continuously pursued to enlarge the examination area of FOV in order to reduce the factors of inconsistency in images that appear in continuous examination during wide area examination using contrast agent such as whole body angiography. In this study, we investigated the optimal FOV by comparing the SNR values according to the changes of FOV. The change of the FOV was gradually changed to $270{\times}200$, $300{\times}223$, $330{\times}244$, $360{\times}266$ and $380{\times}281$. SE images at TR 450 msec and TE 10 msec, FSE images at TR 2,000 msec, TE 80 msec, and GE images were scanned at TR 117 msec, and TE 16 msec. SNR values were calculated from the mean values of signal intensities of five phantom images and the signal intensity values of four background standard deviations. As a result of the study, the signal intensity and the SNR value according to the change of the FOV value gradually increased as the FOV was increased, but it was found that the SNR value decreased at a constant size. In conclusion, the results are different from previous studies that the SNR increases as the FOV increases. The cause of these results could not be confirmed. However methods that can be imaged and included within the effective FOV should be considered.

• 한국의학물리학회지:의학물리
• /
• 제9권1호
• /
• pp.1-9
• /
• 1998

정위적 방사선 수술과 신경외과적 수술분야 에서는 상호보완적인 영상정보를 얻기 위하여 컴퓨터 단층촬영 (CT), 자기공명영상 (MRI) 그리고 혈관조영촬영이 사용된다. 본 연구의 목적은 여러 영상장치와 다목적 QA(Quality Control) 팬톰을 이용하면서, 정위적 방사선수술 및 신경외과적 수술분 야에서 두경부내의 병소에 대한 모양, 크기, 위치를 정확하게 결정하기 위한 3 차원 정위 시스템을 개발하는 것이다. 목표물의 정확한 위치를 정의하기 위하여, Hitchcoke 정위 프레임과 컴퓨터 단층 촬영 (CT)/혈관 조영촬영용 위치측정 보조기구들을 3차원 공간상에 9개의 목표물을 가진 팬톰에 고정하였다. 컴퓨터 단층촬영과 혈관 조영촬영을 이용하여 얻은 기하학적 팬톰의 영상들을 이용하여, 목표물의 3차원 정위좌표를 얻기위한 알고리즘이 개발되었다. 개발된 알고리즘에 의해 계산된 목표물들의 위치는 팬톰의 절대 좌표와 비교 되었고, 각 CT 영상에서의 목표물들은 뇌혈관촬영 영상위에 상호 중첩될 수 있도록 개발 되었다. 512$\times$512 메트릭스와 2mm 슬라이스 두께를 가진 컴퓨터 단층촬영에 있어서는 1.02$\pm$0.17 mm의 평균거리오차를 보였고, 혈관 조영촬영인 경우에는 0.41$\pm$0.05mm 의 평균거리오차를 보였다. 목표물의 위치를 결정하는데 있어서 결과로 나온 정확도는 개발된 시스템이 정위적 방사선수술과 신경외과적수술을 위해 충분히 신뢰성이 있음을 확인해주었다.

• Journal of Magnetics
• /
• 제19권2호
• /
• pp.185-191
• /
• 2014

In this study we evaluated that flow rate changes affect the (time of flight) TOF image and contrast-enhanced (CE) in a three-dimensional TOF angiography. We used a 3.0T MR System, a nonpulsatile flow rate model. Saline was used as a fluid injected at a flow rate of 11.4 cm/sec by auto injector. The fluid signal strength, phantom body signal strength and background signal strength were measured at 1, 5, 10, 15, 20 and 25-th cross-section in the experienced images and then they were used to determine signal-to-noise ratio and contrast-to-noise ratio. The inlet, middle and outlet length were measured using coronal images obtained through the maximum intensity projection method. As a result, the length of inner cavity was 2.66 mm with no difference among the inlet, middle and outlet length. We also could know that the magnification rate is 49-55.6% in inlet part, 49-59% in middle part and 49-59% in outlet part, and so the image is generally larger than in the actual measurement. Signal-to-noise ratio and contrast-to-noise ratio were negatively correlated with the fluid velocity and so we could see that signal-to-noise ratio and contrast-to-noise ratio are reduced by faster fluid velocity. Signal-to-noise ratio was 42.2-52.5 in 5-25th section and contrast-to-noise ratio was from 34.0-46.1 also not different, but there was a difference in the 1st section. The smallest 3D TOF MRA measure was $2.51{\pm}0.12mm$ with a flow velocity of 40 cm/s. Consequently, 3D TOF MRA tests show that the faster fluid velocity decreases the signal-to-noise ratio and contrast-to-noise ratio, and basically it can be determined that 3D TOF MRA and 3D CE MRA are displayed larger than in the actual measurement.

• Investigative Magnetic Resonance Imaging
• /
• 제20권3호
• /
• pp.141-151
• /
• 2016

Purpose: Advances of magnetic resonance imaging (MRI), especially that of the Ultra-High Field (UHF) MRI will be reviewed. Materials and Methods: Diffusion MRI data was obtained from a healthy adult young male of age 30 using a 7.0T research MRI scanner (Magnetom, Siemens) with 40 mT/m maximum gradient field. The specific imaging parameters used for the data acquisition were a single shot DW echo planar imaging. Results: Three areas of the imaging experiments are focused on for the study, namely the anatomy, angiography, and tractography. Conclusion: It is envisioned that, in near future, there will be more 7.0T MRIs for brain research and explosive clinical application research will also be developed, for example in the area of connectomics in neuroscience and clinical neurology and neurosurgery.

• 한국자기학회지
• /
• 제6권4호
• /
• pp.272-276
• /
• 1996

1948년 Harvard 대학의 Purcell교수와 Stanford 대학의 Bloch교수가 핵자기 공명(Nuclear Magnetic Resonance : NMR) 현상을 발견한 이래로 NMR은 물질의 분자단위에서 화학적, 물리학적 성질을 밝혀내는 탁월한 방법으로 널리 이용되어 왔다. NMR 현상을 이용한 영상촬영법(Magnetic Resonance Imaging, MRI)은 1970년대초 Lauterber와 Damadian 교수가 처음 영상을 얻을 수 있다는 가능성을 제시한 이후 급속한 발전을 하여 1980년대 초에는 Moore와 Holland에 의해 의학분야에 응용 가능할 정도의 영상이 얻어졌다. 1980년대 중반부터 상용화 되었으며 최근 그 기법도 NMR현상과 연관된 파라미터인 $T_{1}$, $T_{2}$는 물론 혈류의 속도, 자화율, 확산(Diffusion), Perfusion의 영상기법을 비롯해 혈관조영술(MR Angiography), 뇌기능영상(Functional Imaging)등 과거에는 상상도 할 수 없었던 다양한 영상기법 개발되었다. 여기서는 먼저 MRI의 원리를 설명한 후 MRI의 여러 촬영기법들과 그 응용에 관해 설명하겠다.

• Journal of Yeungnam Medical Science
• /
• 제27권1호
• /
• pp.74-77
• /
• 2010

Isolated hypoglossal nerve palsy is a rare clinical condition and it causes deviation of the tongue and dysarthria. A 50-year-old female presented with tongue deviation to the left and mild dysarthria. She had no remarkable past medical history except several recent upper respiratory infections. On examination, the other cranial nerves were intact and she had no focal neurological signs. The findings of MRI and MR angiography were normal. Cerebrospinal fluid analysis revealed only mild elevation of protein. We diagnosed her as suffering with idiopathic isolated hypoglossal nerver palsy and we administered steroid therapy. The dysarthria was improved, but the tongue deviation still remained at 50 days after onset. We report here on a rare case of idiopathic isolated hypoglossal nerve palsy.

• 대한디지털의료영상학회논문지
• /
• 제17권1호
• /
• pp.43-48
• /
• 2015

Intracrnial 3D TOF MR angiography was performed in 30 normal volunteers with both 1.5 and 3.0 T MRI system with high resolutions. Used Voxel sizes were $0.39{\times}0.39{\times}0.2$(1.5 T) and $0.19{\times}0.19{\times}0.35$(3.0 T), respectively. High image quality and depiction of small vessel branches were equality demonstrated with 1.5 T and 3.0 T HR TOF MRA(p<0.05). Intracranial high resolution TOF MRA with 1.5 T and 3.0 T provides high diagnostic information with having merits and demerits in depiction of vascular branches.