• Korean Journal of Radiology
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• 제21권1호
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• pp.25-32
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• 2020

Objective: To comparatively evaluate the scan coverage and diagnostic performance of the two-view scan technique (2-VST) of the automated breast ultrasound system (ABUS) versus the conventional three-view scan technique (3-VST) in women with small breasts. Materials and Methods: Between March 2016 and May 2017, 136 asymptomatic women with small breasts (bra cup size A) suitable for 2-VST were enrolled. Subsequently, 272 breasts were subjected to bilateral whole-breast ultrasound examinations using ABUS and the hand-held ultrasound system (HHUS). During ABUS image acquisition, one breast was scanned with 2-VST, while the other breast was scanned with 3-VST. In each breast, the breast coverage and visibility of the HHUS detected lesions on ABUS were assessed. The sensitivity and specificity of ABUS were compared between 2-VST and 3-VST. Results: Among 136 breasts, eight cases of breast cancer were detected by 2-VST, and 10 cases of breast cancer were detected by 3-VST. The breast coverage was satisfactory in 94.1% and 91.9% of cases under 2-VST and 3-VST, respectively (p = 0.318). All HHUS-detected lesions were visible on the ABUS images regardless of the scan technique. The sensitivities and specificities were similar between 2-VST and 3-VST (100% [8/8] vs. 100% [10/10], and 97.7% [125/128] vs. 95.2% [120/126], respectively), with no significant difference (p > 0.05). Conclusion: 2-VST of ABUS achieved comparable scan coverage and diagnostic performance to that of conventional 3-VST in women with small breasts.

• Korean Journal of Radiology
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• 제21권11호
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• pp.1210-1219
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• 2020

Objective: To compare the utility and diagnostic performance of automated breast ultrasound system (ABUS) with that of handheld ultrasound (HHUS) in evaluating pure non-mass enhancement (NME) lesions on breast magnetic resonance imaging (MRI). Materials and Methods: One hundred twenty-six consecutive MRI-visible pure NME lesions of 122 patients with breast cancer were assessed from April 2016 to March 2017. Two radiologists reviewed the preoperative breast MRI, ABUS, and HHUS images along with mammography (MG) findings. The NME correlation rate and diagnostic performance of ABUS were compared with that of HHUS, and the imaging features associated with ABUS visibility were analyzed. Results: Among 126 pure NME lesions, 100 (79.4%) were malignant and 26 (20.6%) were benign. The overall correlation rate was 87.3% (110/126) in ABUS and 92.9% (117/126) in HHUS. The sensitivity and specificity were 87% and 50% for ABUS and 92% and 42.3% for HHUS, respectively, with no significant differences (p = 0.180 and 0.727, respectively). Malignant NME was more frequently visualized than benign NME lesions on ABUS (93% vs. 65.4%, p = 0.001). Significant factors associated with the visibility of ABUS were the size of NME lesions on MRI (p < 0.001), their distribution pattern (p < 0.001), and microcalcifications on MG (p = 0.027). Conclusion: ABUS evaluation of pure NME lesions on MRI in patients with breast cancer is a useful technique with high visibility, especially in malignant lesions. The diagnostic performance of ABUS was comparable with that of conventional HHUS in evaluating NME lesions.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.250-257
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• 2007

Functional gastrointestinal disorders affect millions of people of all age regardless of race and sex. There are, however, rare diagnostic methods for the functional gastrointestinal disorders because functional disorders show no evidence of organic and physical causes. Our research group identified recently that the gastrointestinal tract well in the patients with the functional gastrointestinal disorders becomes more rigid than healthy people when palpating the abdominal regions overlaying the gastrointestinal tract. The aim is, therefore, to develop a diagnostic method for the functional gastrointestinal disorders based on quantitative measurement of the rigidity of the gastrointestinal tract well using ultrasound technique. For this purpose, a preliminary ultrasound diagnostic system was developed and verified through phantom tests. The system consisted of transmitter, ultrasonic transducer, receiver, TGC, and CPLD, and verified via a phantom test. For the phantom test, ten soft-tissue specimens were harvested from porcine. Five of them were then treated chemically to mimic a rigid condition of gastrointestinal tract well, which was induced by functional gastrointestinal disorders. Additionally, the specimens were tested mechanically to identify if the mimic was reasonable. The customized ultrasound system was finally verified through application to human subjects with/without functional gastrointestinal disorders(Normal and Patient Groups). It was identified from the mechanical test that the chemically treated specimens were more rigid than normalspecimen. This finding was favorably compared with the result obtained from the phantom test. The phantom test also showed that ultrasound system well described the specimen geometric characteristics and detected an alteration in the specimens. The maximum amplitude of the ultrasonic reflective signal in the rigid specimens $(0.2{\pm}0.1Vp-p)$ at the interface between the fat and muscle layers was explicitly higher than that in the normal specimens $(0.1{\pm}0.0Vp-p)$ (p<0.05). Clinical tests using our customized ultrasound system for human subject showed that the maximum amplitudes of the ultrasonic reflective signals nea. to the gastrointestinal tract well for the patient group$(2.6{\pm}0.3Vp-p)$ were generally higher than those in normal group$(0.1{\pm}0.2Vp-p)$ (p<0.05). These results suggest that newly designed diagnostic system based on ultrasound technique may diagnose enough the functional gastrointestinal disorders.

• Clinical Endoscopy
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• 제56권2호
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• pp.169-179
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• 2023

Background/Aims: This meta-analysis analyzed the effect of an indwelling biliary stent on endoscopic ultrasound (EUS)-guided tissue acquisition from pancreatic lesions. Methods: A literature search was performed to identify studies published between 2000 and July 2022 comparing the diagnostic outcomes of EUS-tissue acquisition (TA) in patients with or without biliary stents. For non-strict criteria, samples reported as malignant or suspicious for malignancy were included, whereas for strict criteria, only samples reported as malignant were included in the analysis. Results: Nine studies were included in this analysis. The odds of an accurate diagnosis were significantly lower in patients with indwelling stents using both non-strict (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.52-0.90) and strict criteria (OR, 0.58; 95% CI, 0.46-0.74). The pooled sensitivity with and without stents were similar (87% vs. 91%) using non-strict criteria. However, patients with stents had a lower pooled sensitivity (79% vs. 88%) when using strict criteria. The sample inadequacy rate was comparable between groups (OR, 1.12; 95% CI, 0.76-1.65). The diagnostic accuracy and sample inadequacy were comparable between plastic and metal biliary stents. Conclusions: The presence of a biliary stent may negatively affect the diagnostic outcome of EUS-TA for pancreatic lesions.

• Clinical Endoscopy
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• 제56권5호
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• pp.658-665
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• 2023

Background/Aims: We aimed to study the effects of sedation on endoscopic ultrasound-guided tissue acquisition. Methods: We conducted a retrospective study evaluating the role of sedation in endoscopic ultrasound-guided tissue acquisition by comparing two groups: anesthesia care provider (ACP) sedation and endoscopist-directed conscious sedation (CS). Results: Technical success was achieved in 219/233 (94.0%) in the ACP group and 114/136 (83.8%) in the CS group (p=0.0086). In multivariate analysis, the difference in technical success between the two groups was not significant (adjusted odds ratio [aOR], 0.5; 95% confidence interval [CI], 0.234-1.069; p=0.0738). A successful diagnostic yield was present in 146/196 (74.5%) in the ACP group and 66/106 (62.3%) in the CS group, respectively (p=0.0274). In multivariate analysis, the difference in diagnostic yield between the two groups was not significant (aOR, 0.643; 95% CI, 0.356-1.159; p=0.142). A total of 33 adverse events (AEs) were observed. The incidence of AEs was significantly lower in the CS group (5/33 CS vs. 28/33 ACP; OR, 0.281; 95% CI, 0.095-0.833; p=0.022). Conclusions: CS provided equivalent technical success and diagnostic yield for malignancy in endoscopic ultrasound-guided tissue acquisition. Increased AEs were associated with anesthesia for the endoscopic ultrasound-guided tissue acquisition.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제20권3호
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• pp.175-202
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• 2016

Ultrasound imaging is a widely used tool for visualizing human body's internal organs and quantifying clinical parameters. Due to its advantages such as safety, non-invasiveness, portability, low cost and real-time 2D/3D imaging, diagnostic ultrasound industry has steadily grown. Since the technology advancements such as digital beam-forming, Doppler ultrasound, real-time 3D imaging and automated diagnosis techniques, there are still a lot of demands for image quality improvement, faster and accurate imaging, 3D color Doppler imaging and advanced functional imaging modes. In order to satisfy those demands, mathematics should be used properly and effectively in ultrasound imaging. Mathematics has been used commonly as mathematical modelling, numerical solutions and visualization, combined with science and engineering. In this article, we describe a brief history of ultrasound imaging, its basic principle, its applications in obstetrics/gynecology, cardiology and radiology, domestic-industrial products, contributions of mathematics and challenging issues in ultrasound imaging.

• Korean Journal of Radiology
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• 제22권2호
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• pp.198-212
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• 2021

Placenta accreta spectrum (PAS) is an abnormal placental adherence or invasion of the myometrium or extrauterine structures. As PAS is primarily staged and managed surgically, imaging can only guide and facilitate diagnosis. But, imaging can aid in preparations for surgical complexity in some cases of PAS. Ultrasound remains the imaging modality of choice; however, magnetic resonance imaging (MRI) is required for evaluation of areas difficult to visualize on ultrasound, and the assessment of the extent of placenta accreta. Numerous MRI features of PAS have been described, including dark intraplacental bands, placental bulge, and placental heterogeneity. Failure to diagnose PAS carries a risk of massive hemorrhage and surgical complications. This article describes a comprehensive, step-by-step approach to diagnostic imaging and its potential pitfalls.

• Journal of Acupuncture Research
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• 제36권4호
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• pp.204-210
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• 2019

This study was performed to evaluate research studies utilizing ultrasound diagnostic units, the practitioners who performed the ultrasound assessments, and how they had been used primarily in tandem with the Korean Medicine Advanced Searching Integrated System. This study identified 46 studies following a literature search, and discovered that a Korean medicine doctor led the ultrasonography in 13 studies, a medical technician was responsible in 6 studies, a roentgenologist carried it out in 5, and 19 of the studies did not specify who had conducted it. Ultrasonography had been actively used in the course of the clinical practice of Korean medicine, and it may serve as a useful and reliable diagnostic tool for evaluating the effectiveness of Korean medicine. The results of this study will help to promote more ultrasound studies in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권3호
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• pp.678-700
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• 2023

Diagnosing breast diseases using ultrasound (US) images remains challenging because it is time-consuming and requires expert radiologist knowledge. As a result, the diagnostic performance is significantly biased. To assist radiologists in this process, computer-aided diagnosis (CAD) systems have been developed and used in practice. This type of system is used not only to assist radiologists in examining breast ultrasound images (BUS) but also to ensure the effectiveness of the diagnostic process. In this study, we propose a new approach for breast lesion localization and segmentation using a multi-scale pyramid of the ultrasound image of a breast organ and a convolutional semantic segmentation network. Unlike previous studies that used only a deep detection/segmentation neural network on a single breast ultrasound image, we propose to use multiple images generated from an input image at different scales for the localization and segmentation process. By combining the localization/segmentation results obtained from the input image at different scales, the system performance was enhanced compared with that of the previous studies. The experimental results with two public datasets confirmed the effectiveness of the proposed approach by producing superior localization/segmentation results compared with those obtained in previous studies.

• 한국정밀공학회지
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• 제24권9호
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• pp.130-139
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• 2007

The disaster from functional gastrointestinal disorders (FGID) has detrimental impact on the quality of life of the affected population. There are, however, rare diagnostic methods for FGID. Our research group identified recently that the gastrointestinal tract well of the patients with FGID became more rigid than that of healthy people when palpating the abdominal regions overlaying the gastrointestinal tract. The objective of the current study is, therefore, to identify feasibility of a diagnostic system for FGID based on ultrasound technique, which can quantify the characteristics above. Two-dimensional finite difference (FD) models (one normal and two rigid models) were developed to analyze the reflective characteristic (displacement) on each soft-tissue layer responded after application of ultrasound signals. Based on the results from FD analysis, the ultrasound system for diagnosis of the FGID was developed and clinically tested via application of it to 40 human subjects with/without FGID who were assigned to Normal and Patient Groups. The results from FD analysis showed that the maximum displacement amplitude in the rigid models (0.12 and 0.16) at the interface between the fat and muscle layers was explicitly less than that in the normal model (0.29). The results from actual specimens showed that the maximum amplitude of the ultrasound reflective signal in the rigid models $(0.2{\pm}0.1Vp-p)$ at the interface between the fat and muscle layers was explicitly higher than that in the normal model $(0.1{\pm}0.0Vp-p)$. Clinical tests using our customized ultrasound system showed that the maximum amplitudes of the ultrasound reflective signals near to the gastrointestinal tract well for the patient group $(2.6{\pm}0.3Vp-p)$ were generally higher than those in normal group $(0.1{\pm}0.2Vp-p)$. These findings suggest that our customized ultrasound system using the ultrasound reflective signal may be helpful to the diagnosis of the FGID.