• Nuclear Medicine and Molecular Imaging
• /
• v.40 no.6
• /
• pp.293-301
• /
• 2006

Purpose: The aim of the study was to evaluate the hemodynamic changes after successful bypass surgery in patients with atherosclerotic stenosis in ICA using $^{99m}Tc-ECD$ SPECT. Materials and Methods: Fourteen patients (M:F=8:6, mean age; $60{\pm}9$ years) who underwent STA-MCA anastomosis for unilateral atherosclerotic cerebrovascular disease were enrolled. $^{99m}Tc-ECD$ basal/acetazolamide perfusion SPECT studies were performed before, 10 days and 6 months after bypass surgery. Perfusion reserve was defined as the % changes after acetazolamide over rest image. Regional cerebral blood flow and perfusion reserve were compared preoperative, early-postoperative and late-postoperative scans. Results: The mean resting perfusion and decrease in perfusion reserve in affected ICA territory on preoperative scan was $52.4{\pm}3.5\;and\;-7.9{\pm}4.7%$, respectively. The resting perfusion was significantly improved after surgery on early-postoperative scan (mean $53.7{\pm}2.7$) and late-postoperative scan (mean $53.3{\pm}2.5$) compared with preoperative images (p<0.05, respectively). Resting perfusion did not showed further improvement on late-postoperative scan compared with early-postoperative scan. The perfusion reserve was $-3.7{\pm}2.6%$ on early-postoperative scan, and $-1.6{\pm}2.3%$ on late-postoperative scan, which was significantly improved after surgery. Additionally, further improvement of perfusion reserved as observed on late-postoperative scan (p<0.05). While, in the unaffected ICA territory, no significant changes in the resting perfusion and perfusion reserve was observed. Conclusion: The improvement of resting perfusion and perfusion reserve in early-postoperative scan reflects the immediate restoration of the cerebral blood flow by bypass surgery. In contrasts, further improvement of perfusion reserve showing on late-postoperative scan may indicate a good collateral development after surgery, which may indicate good surgical outcome after surgery.

• Investigative Magnetic Resonance Imaging
• /
• v.16 no.1
• /
• pp.67-75
• /
• 2012

Purpose : We studied enhanced method to view the vessels in the brain using Magnetic Resonance Angiography (MRA). Noticing that Maximum Intensity Projection (MIP) image is often used to evaluate the arteries of the neck and brain, we propose a new method for view brain vessels to stereo image in 3D space with more superior and more correct compared with conventional method. Materials and Methods: We use 3T Siemens Tim Trio MRI scanner with 4 channel head coil and get a 3D MRA brain data by fixing volunteers head and radiating Phase Contrast pulse sequence. MRA brain data is 3D rotated according to the view angle of each eyes. Optimal view angle (projection angle) is determined by the distance between eye and center of the data. Newly acquired MRA data are projected along with the projection line and display only the highest values. Each left and right view MIP image is integrated through anaglyph imaging method and optimal stereoscopic MIP image is acquired. Results: Result image shows that proposed method let enable to view MIP image at any direction of MRA data that is impossible to the conventional method. Moreover, considering disparity and distance from viewer to center of MRA data at spherical coordinates, we can get more realistic stereo image. In conclusion, we can get optimal stereoscopic images according to the position that viewers want to see and distance between viewer and MRA data. Conclusion: Proposed method overcome problems of conventional method that shows only specific projected image (z-axis projection) and give optimal depth information by converting mono MIP image to stereoscopic image considering viewers position. And can display any view of MRA data at spherical coordinates. If the optimization algorithm and parallel processing is applied, it may give useful medical information for diagnosis and treatment planning in real-time.

• Journal of the Korean Society of Radiology
• /
• v.83 no.3
• /
• pp.719-723
• /
• 2022

Rosai-Dorfman Disease (RDD) is a rare lymphoproliferative disease, and the occurrence of isolated intracranial RDD is extremely rare. Most cases of intracranial RDDs present as dural masses showing homogenous enhancement on MRI, which makes it difficult to differentiate these masses from meningiomas before surgery unless massive cervical lymphadenopathy is observed. We herein report a rare case of isolated intracranial RDD in a 65-year-old male. Brain MRI revealed a well-defined enhancing mass-like lesion involving the right frontal convexity and subtle diffusion restriction. However, only a subtle blush was observed on the preoperative cerebral angiogram. Although instances of isolated intracranial RDD are rare, it should be considered as a potential differential diagnosis when a dural mass with hypovascularity is visualized on the cerebral angiogram.

• The Korean Journal of Nuclear Medicine
• /
• v.22 no.2
• /
• pp.157-161
• /
• 1988

Cerebral rete mirabile는 잘 알려진 뇌혈관 질환으로 뇌혈관촬영상 내경동맥이 심한 협착 혹은 폐색, 뇌저부의 이상혈관망 형성 및 다수의 연수막동맥간문합과 경경수막 외내경동맥간문합의 특징적 소견을 나타낸다. 최근 방사성의약품의 발전과 함께, Tc-99m-HMPAO를 이용한 뇌SPECT는 뇌혈류역학의 평가, 병소의 조기발견 및 병소의 정확한 위치를 알기위한 상용진단 방법이 되었다. 저자들은 뇌 혈관촬영으로 확진된 10명 의 Cerebral rete mirabile 환자에서 뇌 전산화단층촬영과 Tc-99m-HMPAO를 이용한 국소뇌혈류 SPECT를 검토하였다. 대상환자중 남자는 3명, 여자는 7명이었으며, 연령분포는 6세에서 38세이었다. 1) Tc-99m-HMPAO를 이응한 국소 뇌혈류 SPECT는 뇌의 경색부위 뿐만 아니라 허혈부위까지 나타냈으며, cerebral rete mirabile에서의 뇌의 침습된 부위를 나타내는데 있어서 뇌전산화단층촬영보다 우월하였다. 또한 모든 예에서 뇌전산화반층촬영보다 더 넓은 허혈부위를 보여주었다. 2) 다른 허혈성 뇌혈관질환과 비교하여 cerebral rete mirabile는 비균질성 방사능을 나타냈고, 이는 측부순환로에 의한 것으로 추측된다. 3) Tc-99m-HMPAO를 이용한 국소뇌혈류 SPECT는 뇌의 허혈부위의 범위를 평가, 문합수술의 계획 및 cerebral rete mirabile의 경과를 추적하는데 유용한 검사이다.

• Journal of Chest Surgery
• /
• v.31 no.2
• /
• pp.113-117
• /
• 1998

From October 1993 to April 1997, 37 patients(30 male and 7 female patients), ranging in age from 23 to 73 years, were operated for annuloaortic ectasia with or without aortic dissection. Four patients were in New York Heart Association Class I, 10 in Class II, 20 in Class III, and 3 in Class IV. In cases of annuloaortic ectasia with aortic dissection, the surgical treatment in all cases consisted of total replacement of the ascending aorta with composite graft and reimplantation of the coronary arteries to the tube graft. The postoperative complication, as postoperative bleeding or LV dysfunction, was 18%(7 cases) and late mortality for entire group was 2.7%(one death). The period of follow-up ranged from 1 month to 36 months(average 9.6 months). In conclusion, Bentall operation for annuloaortic ectasia with or without aortic dissection is reliable method with low mortality and excellent short-term results.

• Journal of the Korean Orthopaedic Association
• /
• v.55 no.1
• /
• pp.85-89
• /
• 2020

Bow hunter's syndrome is a rare disease that shows the symptoms of vertebrobasilar insufficiency resulting from a dynamic obstruction or stenosis of the vertebral arteries during neck movement. This paper reports a case of a 59-year-old male who visited the emergency room with diplopia, tinnitus, and gait disturbance. Magnetic resonance imaging and angiography revealed a multiple cerebellar infarct, total obstruction of the right vertebral artery, and dynamic obstruction of the left vertebral artery during neck extension. As the infarction worsened, a thrombectomy was done. Posterior decompression and fusion at C5-6 were performed for the left vertebral artery. The left vertebral arterial patency was confirmed by intraoperative and postoperative angiography. No recurrence of the symptoms was observed for six months after surgery. Physicians need to pay attention to the diagnosis of vertebrobasilar insufficiency caused by an obstruction of the vertebral arteries during neck extension in cervical instability patients.

• Journal of Yeungnam Medical Science
• /
• v.2 no.1
• /
• pp.53-57
• /
• 1985

Many pictures must be taken for the presumption of the stereorelation of the cerebral artery, which obtained with ordinary cerebral angiography. And it is very difficult to understand the stereoimage and required many experiences. But it is able to presume the stereorelationship in only brief eye's training without the aid of the stereoscope using the prism. For the stereoview, we need the paired angiograms obtained only straight and tilting the X-ray tube. In practice, with this stereoview in cerebral angiogram, we could know the directions of the aneurysmal neck and fundus with the stereorelationship of the cerebral artery and indeed helps us greatly in operation field. In addition, we might guess the location and stereorelationships of the feeding artery and draining vein in arteriovenous malformation and other vascular tumors and it was great aid in diagnosis and operation. Now we present the methods of the pictures for the stereoview in cerebral angiogram and the methods for eye's training.

• The Korean Journal of Nuclear Medicine
• /
• v.36 no.6
• /
• pp.357-367
• /
• 2002

Purpose: While cerebral blood flow and cerebrovascular reserve could be evaluated with basal/acetazolamide Tc-99m-HMPAO SPECT in cerebrovascular disease, objective quantification is necessary to assess the efficacy of the revascularization. In this study we adopted the SPM method to quantify basal cerebral blood flow and cerebrovascular reserve on basal/acetazolamide SPECT in assessment of the patients who underwent bypass surgery for linternal carotid artery (ICA) stenosis. Materials and Methods: Twelve patients ($51{\pm}15$ years) with ICA stenosis were enrolled. Tc-99m-HMPAO basal/acetazolamide perfusion SPECT was peformed before and after bypass surgery. After spatia1 and count normalization to cerebellum, basal cerebral blood flow and cerebrovascular reserve were compared with 21 age-matched normal controls and postoperative changes of regional blood flow and reserve were assessed by Statistical Parametric Mapping method. Mean pixel values of each brain region were calculated using probabilistic anatomical map of lobes. Perfusion reserve was defined as the % changes after acetazolamide over basal counts. Results: Preoperative cerebral blood flow and cerebrovascular reserve were significantly decreased in involved ICA territory, comparing with normal control (p<0.05). Postoperative improvement of cerebral blood flow and cerebrovascular reserve was observed in grafted ICA territories, but cerebrovasculr reserve remained with significant difference with normal control. Improvement of the cerebrovascular reserve was most prominent in the superior temporal and the angular gyrus, nearest to the anastomosis sites. Conclusion: Using SPM quantification method on hasal/acetazolamide Tc-99m-HMPAO SPECT, the cerebral blood flow and cerebrovascular reserve could be assessed before revascularization and so could the efficacy of the bypass surgery.

• Progress in Medical Physics
• /
• v.9 no.1
• /
• pp.1-9
• /
• 1998

In order to provide complementary image data, CT(computed tomography), MR(magnetic resonance) and angiography have been used in the field of Stereotactic Radiosurgery(SRS) and neurosurgery. The aim of this work is to develop 3-D stereotactic localization system in order to determine the precise shape, size and location of the lesion in the brain in the field of Stereotactic Radiosurgery(SRS) and neurosurgery using multi-image modality and multi purpose QA phantom. In order to obtain accurate position of a target, Hitchcoke stereotactic frame and CT/angiography localizers were rigidly attached to the phantom with nine targets dispersed in 3-D space. The algorithms to obtain a 3-D stereotactic coordinates of the target have been developed using the images of the geometrical phantom which were taken by CT/angiography. Positions of targets computed by our algorithms were compared to the absolute position assigned in the phantom. Outlines of targets on each CT image were superimposed each other on angiography images. A spatial mean distance errors were 1.02${\pm}$0.17mm for CT with a 512${\times}$512 matrix and 2mm slice thickness, 0.41${\pm}$0.05mm for angiogra- phy localization. The resulting accuracy in the target localization suggests that the developed system has enough Qualification for Stereotactic Radiosurgery (SRS).

• Proceedings of the KOSOMBE Conference
• /
• v.1998 no.11
• /
• pp.117-118
• /
• 1998

The aim of this work is to develop 3-D stereotactic localization system in order to determine the precise shape, size and location of the lesion in the brain in the field of Stereotactic Radiosurgery(SRS) and neurosurgery using CT/MRI/angiography and multi-purpose QA phantom. The algorithms to obtain a 3-D stereotactic coordinates of the target have been developed, and targets on each CT image were superimposed each other on MR/angiography images without distortion corretion. This system was implented in Visual C++ as a PC-based application program.