• Journal of Korean Neurosurgical Society
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• v.49 no.2
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• pp.107-111
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• 2011

Objective : The aim of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography focusing tracheostomy tube and innominate artery for prevention of tracheoinnominate artery fistula. Methods : The authors retrospectively analyzed 22 patients with tracheostomy who had checked CT angiography. To evaluate the relationship between tracheostomy tube and innominate artery, we divided into three categories. First proximal tube position based on cervical vertebra, named "tracheostomy tube departure level (TTDL)". Second, distal tube position and course of innominate artery, named "tracheostomy tube-innominate artery configuration (TTIC)". Third, the gap between the tube and innominate artery, named "tracheostomy tube to innominate artery gap (TTIG)". The TTDL/TTIC and TTIG are based on 3-dimensional (3D) reconstruction around tracheostomy and enhanced axial slices of upper chest, respectively. Results : First, mean TTDL was $6.8{\pm}0.6$. Five cases (23%) were lower than C7 vertebra. Second, TTIC were remote to innominate artery (2 cases; 9.1 %), matched with it (14 cases; 63.6%) or crossed it (6 cases; 27.3%). Only 9% of cases were definitely free from innominate artery injury. Third, average TTIG was $4.3{\pm}4.6$ mm. Surprisingly, in 6 cases (27.3%), innominate artery, trachea wall and tracheostomy tube were tightly attached all together, thus have much higher probability of erosion. Conclusion : If low TTDL, match or crossing type TTIC with reverse-L shaped innominate artery, small trachea and thin TTIG are accompanied all together, we may seriously consider early plugging and tube removal.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.3-27
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• 2022

Cardiac CT has been proven to provide diagnostic and prognostic evaluation of coronary artery disease for cardiovascular risk stratification and treatment decision-making based on rapid technological development and various research evidence. Coronary CT angiography has emerged as a gateway test for coronary artery disease that can reduce invasive angiography due to its high negative predictive value, but the diagnostic specificity is relatively low. However, coronary CT angiography is likely to overcome its limitations through functional evaluation to identify the hemodynamic significance of coronary artery disease by analyzing myocardial perfusion and fractional flow reserve through cardiac CT. Recently, studies have been actively conducted to incorporate artificial intelligence to make this more objective and reproducible. In this review, functional imaging techniques of cardiac computerized tomography are explored.

• Journal of Korean Neurosurgical Society
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• v.45 no.5
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• pp.284-288
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• 2009

Objective : Our retrospective study aimed to determine whether 16-slice computerized tomography (CT) angiography optimized sharp kernel is suitable for the evaluation of visibility, luminal patency and re-stenosis of intracranial stents in comparison with conventional angiography. Methods : Fifteen patients with symptomatic intracranial stenotic lesions underwent balloon expandable stent deployment of these lesions (10 middle cerebral arteries, 2 intracranial vertebral arteries, and 3 intracranial internal carotid arteries). CT angiography follow-up ranged from 6 to 15 months (mean follow-up, 8 months) after implantation of intracranial stents and conventional angiography was confirmed within 2 days. Curved multiplanar reformations with maximal intensity projection (MIP) with optimal window settings for assessment of lumen of intracranial stents were evaluated for visible lumen diameter, stent patency (contrast distal to the stent as an indirect sign), and re-stenosis by two experienced radiologists who blinded to the reports from the conventional angiography. Results : All of stents deployed into symptomatic stenotic lesions. All stents were classified as patent and no re-stenosis, which was correlated with results of conventional angiography. Parts of the stent lumen could be visualized in all cases. On average, 57% of the stent lumen diameter was visible using optimized sharp kernel. Significant improvement of lumen visualization (22%, p<0.01) was observed using the optimized sharp kernel compared with the standard sharp kernel. Inter-observer agreements on the measurement of lumen diameter and density were judged as good, respectively (p<0.05). Conclusion : Sixteen-slice CT using the optimized sharp kernel may provide a useful information for evaluation of lumen diameter patency, and re-stenosis of intracranial stents.

• Journal of Korean Neurosurgical Society
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• v.39 no.2
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• pp.125-129
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• 2006

Objective : The purpose of this study is to identify any differential point in computerized tomographic[CT] findings between aneurysmal subarachnoid hemorrhage[ASAH] and traumatic subarachnoid hemorrhage[TSAH], which sometimes make us not confident in differentiation. Methods : CT of 142 ASAH and 82 TSAH patients over the last 2 years were retrospectively reviewed. We evaluated the thickness of SAH, the laterality of sylvian cisternal hemorrhage, the location, the number of involved cisterns, and the associated other lesions between two types of SAH. Results : Suprasellar cisterns and sylvian cisterns were most prominently and frequently involved cisterns in ASAH but cortical sulci and sylvian cisterns were most frequently involved in TSAH. Intraventricular and intracerebral hemorrhage were frequently seen in ASAH. Thickness of SAH over 1mm, bilateral sylvian SAH, multiple cisternal SAH were in favor of ASAH. The number of involved cisterns were more frequently seen in ASAH than in TSAH. In ASAH, bilateral sylvian hemorrhages were more frequently seen than in TSAH. Skull fracture, subdural hematoma, subgaleal hematoma, and hemorrhagic contusion were frequently associated with TSAH. Conclusion : As a result of our study, the authors conclude that when IVH, hydrocephalus, thick SAH > 1mm bilateral sylvian SAH, and multiple cisternal SAH are seen in CT, immediate angiography should be performed to rule out cerebral aneurysms whether associated with other traumatic lesions or not.

• Journal of KIISE:Software and Applications
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• v.30 no.12
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• pp.1247-1254
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• 2003

Currently. the north american symptomatic carotid endarterectomy trial, european carotid surgery trial, and common carotid method are used to measure the carotid stenosis for determining candidate for carotid endarterectomy using the projection angiography from different modalities such as digital subtraction angiography. rotational angiography, computed tomography angiography and magnetic resonance angiography. A new computerized carotid stenosis measuring system was developed using MR angiography axial image to overcome the drawbacks of conventional carotid stenosis measuring methods, to reduce the variability of inter-observer and intra-observer. The gray-level thresholding is one of the most popular and efficient method for image segmentation. We segmented the carotid artery and lumen from three-dimensional time-of-flight MRA axial image using gray-level thresholding technique. Using the measured intima-media thickness value of common carotid artery for each cases, we separated carotid artery wall from the segmented carotid artery region. After that, the regions of segmented carotid without artery wall were divided into region of blood flow and plaque. The calculation of carotid stenosis degree was performed as the following; carotid stenosis grading is(area measure of plaque/area measure of blood flow region and plaque) * 100%.

• Journal of Korean Neurosurgical Society
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• v.42 no.5
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• pp.413-415
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• 2007

A 26-year-old man was admitted to our department due to intermittent left hemiparesis for 3 months. Magnetic resonance Image showed subacute infarction in the right precentral gyrus. Digital subtraction angiography and magnetic resonance angiography revealed an aneurysmal protrusion at the right middle cerebral artery (MCA) bifurcation. It was difficult to differentiate the aneurysm from the occlusion of the middle trunk of the MCA trifurcation. Brain single photon emission computerized tomography showed a decrease in perfusion in the right posterior frontal lobe without vascular reserve. Therefore, we planned a superficial temporal artery MCA anastomosis with an exploration of the right MCA bifurcation. Intraoperatively, the aneurysmal opacification on preoperative angiography proved to be the proximal stump of the occluded middle trunk of the MCA trifurcation. An aneurysmal protrusion at the MCA bifurcation does not always indicate an aneurysm. In diagnosing protruding vascular lesions at the MCA bifurcation, the possibility of a vascular stump should be considered according to their angioanatomical appearance and the history of the patient.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1157-1159
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• 1996

Atherosclerotic giant aneurysm of the common femoral artery is rare. Because the patients who lose timing of the operation face amputation or death, the surgical treatment must be performed at the proper time. A 72-old man was admitted to the hospital because of a 20-days history of pulsatile growing mass on his left groin. After the diagnosis of giant aneurysm of the common femoral artery by computerized tomography and digital subtraction angiography, an emergent operation was performed. Both deep and superficial femoral arteries were successfully reconstructed with Gore-tex grafts after aneurysmectomy. The pathology of the aneurysm was proved to be atherosclerosis.

• Tuberculosis and Respiratory Diseases
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• v.56 no.1
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• pp.85-90
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• 2004

A 69 year-old female was admitted to the hospital due to intermittent hemoptysis for 1 month. Emergent bronchoscopy revealed mass-like lesion almost completely obstructing right intermediate bronchus with multiple hemorrhagic spots. Bronchial arterial angiography was performed but failed to find out actively bleeding vessel. Spiral computerized tomography of the chest showed contrast enhanced bulging of the posterior portion of right main bronchus into the lumen of right intermediate bronchus suggesting Rasmussen aneurysm. The AFB smear of bronchial washing fluid was positive. Pulmonary arterial angiography and embolization were not performed due to improvement of clinical course with medical conservative care. Here we report a case of endobronchial mass-like Rasmussen aneurysm grossly suspected by bronchoscopy and diagnosed by spiral CT, which successfully managed by medical conservative care with antituberculous agents.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.400-404
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• 1995

Focal nodular hyperplasia is a benign hepatic tumor mainly composed of nodules of hepatocytes and Kupffer cells separated by fibrous septa. In general, it is difficult to differentiate focal nodular hyperplasia and hepatocellular carcinoma on ultrasonography, conventional CT(computerized tomography), and angiography. But IV bolus CT is of particular value in the diagnosis of focal nodular hyperplasia because it can divide enhanced CT into early and late phase and can characterize tumor vascularity and analyze any intratumoral elements. In our case, it was seen as a hypoechoic mass lesion on ultrasonography and hyperdense mass lesion on early-phase IV bolus CT and isodense mass lesion on late-phase IV bolus CT. On angiography, hypertrophy of the feeding artery and tumor staining were well visualized. The patient underwent operation and the mass was pathologically confirmed to a focal nodular hyperplasia. We report the first case of focal nodular hyperplasia on IV bolus CT in Korea.

• Journal of Korean Neurosurgical Society
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• v.50 no.3
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• pp.252-255
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• 2011

Authors report a case of a painless acute dissecting aneurysm of the descending aorta in a patient who presented with unexplained hypotension followed by simultaneous paraplegia and right arm monoparesis. To our knowledge, case like this has not been reported previously. Magnetic resonance imaging of the brain and spine revealed hemodynamic cerebral infarction and extensive cord ischemia, respectively. Computerized tomography angiography confirmed a dissecting aneurysm of the descending aorta. The cause of the brain infarction may not have been embolic, but hemodynamic one. Dissection-induced hypotension may have elicited cerebral perfusion insufficiency. The cause of cord ischemia may be embolic or hemodynamic. The dissected aorta was successfully replaced into an artificial patch graft. The arm monoparesis was improved, but the paraplegia was not improved. In rare cases of brain and/or spinal cord infarction caused by painless acute dissecting aneurysm of the aorta, accurate diagnosis is critical because careless thrombolytic therapy can result in life-threatening bleeding.