• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.159-163
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• 1997

The complications of deep neck infection have become much less common in the antibiotic era. The vascular complications of deep neck infection can have devasting consequences. Most commonly, the internal carotid artery is involved, although the common carotid and external carotid artery can also be affected.0 the cases of patients with a protracted course, recurrent bleeding, cranial neuropathies, or trismus, the presence of vascular complications must be considered. Appropriate imaging should be carried out to allow the localization of the infection and ascertain the status of the vessels in the neck The vascular structures can be imaged with duplex doppler or color doppler flow ultrasound to see the flow between the mass and vessels. Also angiography plays a key role in the diagnosis and management of vascular complication of deep neck infection. Prompt diagnosis and treatment of these patients is necessary to prevent significant hemmorrhagic complications. We experienced a case of pseudoaneurysm of the common carotid artery secondary to deep neck infection treated successfully with surgical excision in 45-year-old-male.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.169-180
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• 2019

Transmitting visual information over a broadcasting network is not only prone to a copyright violation but also is a forgery. Authenticating such information and protecting its authorship rights call for more advanced data encoding. To this end, electronic watermarking is often adopted to embed inscriptive signature in imaging data. Most existing watermarking methods while focusing on robustness against degradation remain lacking of measurement against security loophole in which the encrypting scheme once discovered may be recreated by an unauthorized party. This could reveal the underlying signature which may potentially be replaced or forged. This paper therefore proposes a novel digital watermarking scheme in temporal-frequency domain. Unlike other typical wavelet based watermarking, the proposed scheme employed the Lorenz chaotic map to specify embedding positions. Effectively making this is not only a formidable method to decrypt but also a stronger will against deterministic attacks. Simulation report herein highlights its strength to withstand spatial and frequent adulterations, e.g., lossy compression, filtering, zooming and noise.

• Ocean Systems Engineering
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• v.10 no.4
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• pp.435-449
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• 2020

This paper proposes a method to estimate the underwater target object's yaw angle using a sonar image. A simulator modeling imaging mechanism of a sonar sensor and a generative adversarial network for style transfer generates realistic template images of the target object by predicting shapes according to the viewing angles. Then, the target object's yaw angle can be estimated by comparing the template images and a shape taken in real sonar images. We verified the proposed method by conducting water tank experiments. The proposed method was also applied to AUV in field experiments. The proposed method, which provides bearing information between underwater objects and the sonar sensor, can be applied to algorithms such as underwater localization or multi-view-based underwater object recognition.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.1
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• pp.87-91
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• 2022

Ingestion of foreign bodies (FBs) is a common phenomenon among young children. Plain radiography is the first step diagnostic modality to detect the radio-opaque FBs. And computed tomography has been recommended by several guidelines as useful modalities for diagnosing ingested FBs. However, there is a risk of radiation exposure, making it burdensome to use in asymptomatic patients. Ultrasound (US) is not a commonly used technique for diagnosing ingested foreign bodies. However, US can provide real-time imaging with good resolutions without radiation exposure in pediatric patients. Herein, we report two pediatric cases of metallic foreign body ingestion that were successfully diagnosed using US for localizing foreign bodies. This study indicates that US may be used as an alternative method for detecting the localization of metallic foreign bodies in the gastrointestinal tract without exposure of radiation, particularly in pediatric patients.

• Journal of the Korean Society of Radiology
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• v.84 no.2
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• pp.332-344
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• 2023

The role of ultrasound-guided interventions in the diagnosis and treatment of breast lesions is gaining importance and prevalence, particularly as the instances of non-palpable breast lesion detection, breast-conserving surgery, and neoadjuvant chemotherapy are increasing. This review attempts to summarize the types and techniques of breast ultrasound-guided interventional procedures, such as biopsy, tissue marker insertion, and preoperative localization, and their indications. Furthermore, we highlight the pro and cons of the most commonly used procedures with the intention of promoting their use in clinical practice.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4929-4932
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• 2014

Objective: To compare the mammogarphic appearance between breast cancer patients aged <40 and ${\geq}40$ years. Methods: Needle localization and biopsy of suspicious mammographic lesions identified 1,959 breast carcinomas in a single institution from Jun 2012 to Apr 2013. According to the age, we divided patients into two groups: <40 and ${\geq}40$ years old, and analyzed mammographic appearance separately. Results: Young patients had 44.2% foci with calcification, but old patients only had 39.4% (P<0.001). In younger group, the ratios of cases according to mass density were 41.8% or higher, 58.2% equivalent and lower. In older group, the ratios were 55.5 % and 44.5%, respectively. There were statistical differences between high density and others (P<0.05). The ratios of cases according to mass margin were 13.9% circumscribed and microlobulated, 86.1% indistinct and spiculated in the younger group, as compared to 6.5% and 93.5%, respectively, in the older group (P<0.05). Conclusions: Mammographic findings differ between young and old patients with breast cancer, for example regarding mass density, mass margin and microcalcification ratios.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.10-19
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• 1998

The SPECT radiopharmaceuticals labeled with I-123 for dopamine transporter imaging have been used to measure dopamine transporters in patients with movement disorders. However, a cyclotron produced I-123 limits its availiability and ease of use as a radioisotope to be labeled with pharmaceuticals in routine clinical diagnostic procedures. Recently, new radiophannaceuticals for Tc-99m which has optimal characteristic for SPECT imaging have been developed to overcome the limits of using I-123. The purpose of this study was to compare the quality of [Tc-99m]TRODAT-1 with [I-123]IPT SPECT data and then to evaluate the usefulness of [Tc-99m]TRODAT-1 SPECT by using three noninvasive simplified quantitative methods. TRODAT-1 labeled with Tc-99m($15.93{\pm}0.82mCi$) and IPT labeled with I-123($6.60{\pm}0.11mCi$) were injected into five normal controls. Dynamic [Tc-99m]TRODAT-1 SPECT scans of brain were performed for 10 minutes each over 180 minnutes, and for 20 minutes at 4 hrs and 5 hrs. [I-123]IPT SPECT scans were performed for 5 minutes each over 120 minutes. Time activity curves were generated for the left basal ganglia(LBG), right basal ganglia(RBG), and occipital cortex(OCC). Dopamine transporter parameters were ohtained using (BG-OCC)/OCC, graphical method($R_V$), and area ratio method($R_A$). TRODAT-1 and IPT SPECT imaging showed high uptake at the level of the basal ganglia. (BG-OCC)/OCC ratios for TRODAT-1 and IPT were $0.80{\pm}0.14$, and $3.22{\pm}0.81$, $R_Vs$ were $0.62{\pm}0.12$, and $2.30{\pm}0.35$, and $R_As$ were $0.37{\pm}0.08$ and $1.73{\pm}0.31$, respectively. In conclusion, further improvement of [Tc-99m]TRODAT-1 imaging characteristics may be required to estimate the dopamine transporter concentrations in human brains although it shows clear BG localization.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.15-21
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• 1995

To evaluate availability of cerebral radionuclide imaging for diagnosis of brain death, we examined 25 patients with a suspected clinical diagnosis of brain death. 8 patients were studied by $^{99m}Tc$ DTPA and 15 patients were studied by $^{99m}Tc$ HMPAO (Hexamethyl propyleneamine oxime). Seven patients with $^{99m}Tc$ DTPA studies revealed absence of cerebral blood flow and sagittal sinus activity. All of 15 patients with $^{99m}Tc$ HMPAO studies revealed complete absence of cerebral perfusion. The results of the cerebral radionuclide studies of brain death correlated with other clinical conditions, such as intracranial pressure(ICP), EEG, transcranial doppler sonography(TCDS), and neurologic examination. The ICP of 8 patients, who are confirmed by brain death with $^{99m}Tc$ HMPAO study are elevated in all cases. In conclusion, cerebral radionuclide imaging for diagnosis of brain death is available. $^{99m}Tc$ HMPAO imaging is unequivocal, easily interpreted, well reflect the physiologic state of increased ICP, and provides adequate assessment of posterior fossa activity. In addition, the SPECT imaging with $^{99m}Tc$ HMPAO produces more accurate results due to it's superiority of image contrast and proper localization of radiopharmaceutical distribution than conventional planar imaging.

• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.126-133
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• 2010

Purpose : The study was to evaluate the localization of the abnormal gyral and sulcal patterns obtained by means of brain surface rendering imaging. Materials and Methods : Nineteen patients with cortical dysplasia who underwent brain surface rendering MR imaging were included in this study. We acquired MP-RAGE sequence and created the 3-D surface rendering MR images by using $VoxelPlus^{(R)}$. Anatomical locations and configurations of abnormal gyri and sulci were reviewed. Results : Abnormal gyral and sulcal patterns were seen 18 in 19 patients. The configuration and orientation of affected gyri and sulci were clearly evaluated in the brain surface rendering images. In a lissencephaly, the a cortex was not delineated and showed markedly thick and smooth gyral pattern. In a schizencephaly, there were wheel shaped broad gyral pattern around the cleft. In a hemimegalencephaly, an affected hemisphere were enlarged and displayed thick and wide gyral pattern. In CBPS, the insular cortex was exposed and the gyri of the lesion were thickened. In focal cortical dysplasia, there were irregular serrated or thick and enlarged gyri. Conclusion : Brain surface rendering MR imaging is useful for the evaluation of a detailed gyral pattern and accurate involvement site of abnormal gyri.

• Korean Journal of Radiology
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• v.24 no.6
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• pp.553-563
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• 2023

Objective: Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging-derived tractography (DTI-t) contribute to the localization of language areas, but their accuracy remains controversial. This study aimed to investigate the diagnostic performance of preoperative fMRI and DTI-t obtained with a simultaneous multi-slice technique using intraoperative direct cortical stimulation (DCS) or corticocortical evoked potential (CCEP) as reference standards. Materials and Methods: This prospective study included 26 patients (23-74 years; male:female, 13:13) with tumors in the vicinity of Broca's area who underwent preoperative fMRI and DTI-t. A site-by-site comparison between preoperative (fMRI and DTI-t) and intraoperative language mapping (DCS or CCEP) was performed for 226 cortical sites to calculate the sensitivity and specificity of fMRI and DTI-t for mapping Broca's areas. For sites with positive signals on fMRI or DTI-t, the true-positive rate (TPR) was calculated based on the concordance and discordance between fMRI and DTI-t. Results: Among 226 cortical sites, DCS was performed in 100 sites and CCEP was performed in 166 sites. The specificities of fMRI and DTI-t ranged from 72.4% (63/87) to 96.8% (122/126), respectively. The sensitivities of fMRI (except for verb generation) and DTI-t were 69.2% (9/13) to 92.3% (12/13) with DCS as the reference standard, and 40.0% (16/40) or lower with CCEP as the reference standard. For sites with preoperative fMRI or DTI-t positivity (n = 82), the TPR was high when fMRI and DTI-t were concordant (81.2% and 100% using DCS and CCEP, respectively, as the reference standards) and low when fMRI and DTI-t were discordant (≤ 24.2%). Conclusion: fMRI and DTI-t are sensitive and specific for mapping Broca's area compared with DCS and specific but insensitive compared with CCEP. A site with a positive signal on both fMRI and DTI-t represents a high probability of being an essential language area.