• 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.

• Journal of Magnetics
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• v.19 no.2
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• pp.185-191
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• 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.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.398-404
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• 2019

Objective : Recently, three-dimensional (3D) printed models of the intracranial vascular have served as useful tools in simulation and training for cerebral aneurysm clipping surgery. Precise and realistic 3D printed aneurysm models may improve patients' understanding of the 3D cerebral aneurysm structure. Therefore, we created patient-specific 3D printed aneurysm models as an educational and clinical tool for patients undergoing aneurysm clipping surgery. Herein, we describe how these 3D models can be created and the effects of applying them for patient education purpose. Methods : Twenty patients with unruptured intracranial aneurysm were randomly divided into two groups. We explained and received informed consent from patients in whom 3D printed models-(group I) or computed tomography angiography-(group II) was used to explain aneurysm clipping surgery. The 3D printed intracranial aneurysm models were created based on time-of-flight magnetic resonance angiography using a 3D printer with acrylonitrile-butadiene-styrene resin as the model material. After describing the model to the patients, they completed a questionnaire about their understanding and satisfaction with aneurysm clipping surgery. Results : The 3D printed models were successfully made, and they precisely replicated the actual intracranial aneurysm structure of the corresponding patients. The use of the 3D model was associated with a higher understanding and satisfaction of preoperative patient education and consultation. On a 5-point Likert scale, the average level of understanding was scored as 4.7 (range, 3.0-5.0) in group I. In group II, the average response was 2.5 (range, 2.0-3.0). Conclusion : The 3D printed models were accurate and useful for understanding the intracranial aneurysm structure. In this study, 3D printed intracranial aneurysm models were proven to be helpful in preoperative patient consultation.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.48-50
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• 2014

A 70-year-old woman presented with headaches and recurrent stroke symptoms. During five years, the patient has been treated for cerebral infarction associated with severe atherosclerotic stenosis of the internal carotid artery. Three-year follow-up magnetic resonance angiography showed a tiny de novo aneurysm arising from the distal part of atherosclerotic internal carotid artery. And 5-year follow-up three-dimensional CT angiogram demonstrated a definite aneurysm enlargement as large as requiring treatment. During dissection of aneurysm, the oculomotor nerve was found to be penetrated with the growing de novo aneurysm. The authors report a case of a de novo aneurysm, which resulted from atherosclerotic stenosis of the internal carotid artery at the supraclinoid portion, that was found to be penetrating the oculomotor nerve with no ocular palsy.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2507-2511
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• 2016

Purpose: To study the diagnostic accuracies of serum human epididymis protein 4 (HE-4) levels, virtual organ computer-aided analysis (VOCAL) parameters and endometrial volume in endometrial cancer cases. Materials and Methods: One hundred and seven patients (37 with endometrial cancer and 70 with benign endometrial pathology) were included in this study. VOCAL parameters and serum HE-4 levels were compared between the groups. Results: Area under the curve (AUC) values were 0.702, 0.658, 0.706 for vascularization index (VI), the flow index (FI) and the vascularization flow index (VFI), respectively. A cut off value of 0.568 for VI demonstrated 70% sensitivity, 72% specificity, 56% positive predictive value (PPV) and a81% negative predictive value (NPV). A cut off value of 25.8 for showed a senitivith of 70% and a specificity of 58% with aPPV of 46% and NPV of 78%, and with a cut off value of 0.12 for VFI 70%, 69%, 54% and 81%, respectively. The area under the curve for HE-4 was 0.814. A cut off value of 458 pmol/L was predictive of malignancy with 86% sensitivity and 63% specificity. Conclusions: VOCAL parameters and serum HE-4 levels were statistically significantly higher in the endometrial cancer patients. Serum HE-4 levels provided a greater sensitivity compared to power doppler angiography for predicting malignancy or benign endometrial pathology.

• Journal of KIISE:Software and Applications
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• v.31 no.7
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• pp.939-948
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• 2004

In this paper. we Propose a robust and fast image registration technique for motion correction in brain CT-CT angiography obtained from same patient to be taken at different time. First, the feature points of two images are respectively extracted by 3D edge detection technique, and they are converted to locally weighted 3D distance map in reference image. Second, we search the optimal location whore the cross-correlation of two edges is maximized while floating image is transformed rigidly to reference image. This optimal location is determined when the maximum value of cross-correlation does't change any more and iterates over constant number. Finally, two images are registered at optimal location by transforming floating image. In the experiment, we evaluate an accuracy and robustness using artificial image and give a visual inspection using clinical brain CT-CT angiography dataset. Our proposed method shows that two images can be registered at optimal location without converging at local maximum location robustly and rapidly by using locally weighted 3D distance map, even though we use a few number of feature points in those images.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.35-45
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• 2019

Objective : To describe our experiences with a fully equipped high-end digital subtraction angiography (DSA) system within a hybrid operating room (OR). Methods : A single-plane DSA system with 3-dimensional rotational angiography, cone-beam computed tomography (CBCT), and real-time navigation software was used in our hybrid OR. Between April 2014 and January 2018, 191 sessions of cerebrovascular procedures were performed in our hybrid OR. After the retrospective review of all cases, the procedures were categorized into three subcategorical procedures : combined endovascular and surgical procedure, complementary rescue procedure during intervention and surgery, and frameless stereotaxic operation. Results : Forty-nine of 191 procedures were performed using hybrid techniques. Four cases of blood blister aneurysms and a ruptured posterior inferior cerebellar artery aneurysm were treated using bypass surgery and endovascular trapping. Eight cases of ruptured aneurysm with intracranial hemorrhage (ICH) were treated by partial embolization and surgical clipping. Six cases of ruptured arteriovenous malformation with ICH were treated by Onyx embolization of nidus and subsequent surgical removal of nidus and ICH. Two (5.4%) of the 37 cases of pre-mature rupture during clipping were secured by endovascular coil embolization. In one (0.8%) complicated case of 103 intra-arterial thrombectomy procedures, emergency surgical embolectomy with bypass surgery was performed. In 27 cases of ICH, frameless stereotaxic hematoma aspiration was performed using $XperGuide^{(R)}$ system (Philips Medical Systems, Best, the Netherlands). All procedures were performed in single sessions without any procedural complications. Conclusion : Hybrid OR with a fully equipped DSA system could provide precise and safe treatment strategies for cerebrovascular diseases. Especially, we could suggest a strategy to cope flexibly in complex lesions or unexpected situations in hybrid OR. CBCT with real-time navigation software could augment the usefulness of hybrid OR.

• Journal of the Korea Computer Graphics Society
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• v.23 no.1
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• pp.49-55
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• 2017

Computed tomographic angiography (CTA) is widely used in the diagnosis and treatment of coronary artery disease because it shows not only the whole anatomical structure of the cardiovascular three-dimensionally but also provides information on the lesion and type of plaque. However, due to the large size of the image, there is a limitation in manually extracting coronary arteries, and related researches are performed to automatically extract coronary arteries accurately. As the coronary artery originate from the ascending aorta, the ascending aorta and ostium should be detected to extract the coronary tree accurately. In this paper, we propose an automatic segmentation for the ostium as a starting structure of coronary artery in CTA. First, the region of the ascending aorta is initially detected by using Hough circle transform based on the relative position and size of the ascending aorta. Second, the volume of interest is defined to reduce the search range based on the initial area. Third, the refined ascending aorta is segmented by using a two-dimensional geodesic active contour. Finally, the two ostia are detected within the region of the refined ascending aorta. For the evaluation of our method, we measured the Euclidean distance between the result and the ground truths annotated manually by medical experts in 20 CTA images. The experimental results showed that the ostia were accurately detected.

• Journal of Trauma and Injury
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• v.28 no.4
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• pp.272-275
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• 2015

Pelvic bone fracture with unstable vital signs is a life-threatening condition demanding proper diagnosis and immediate treatment. Unlike long bones, the pelvic bone is a three dimensional structure with complex holes and grooves for vessels and nerves. Because of this complexity, a pelvic bone fracture can lead to complicated and serious bleeding. We report a case of a fifty-year-old male suffering from a pelvic bone fracture due to a fall. An imaging study showed fractures of both the superior and the inferior ramus of the pubic bone, with contrast extravasation underneath them, resulting in a large preperitoneal hematoma. He was sent for angiography, which revealed a hemorrhage from a branch of the left obturator artery. Embolization was done with a glue and lipiodol mixture. The patient recovered without complication, and was discharged at four weeks after admission.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.32-34
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• 2002

Over the past two decades there has been a tremendous growth in the number of synchrotron radiation facilities in the world and also in Japan. The high flux and brightness radiation which derive from the third generation low emittance rings provide an ideal source for many applications in the medical sciences. The application of synchrotron radiation to medical imaging started in the early 80's in U.S.A, followed by European countries such as Germany and Russia. In Japan, researchs on intravenous coronary angiography started in 1884 at the Institute for High Energy Phisics(KEK) in Tsukuba. At present, it is the only application of syncrotron radiation which is at the stage of human study. In '90s, newer techniques such as phase and refraction contrast imaging appeared which are at the in vitro or animal study stage. Various types of x-ray CT have also been developed for three-dimensional imaging of the subjects. The present status of medical applications of synchrotron radiation in Japan is reviewed.