• 대한방사선기술학회지:방사선기술과학
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• 제41권4호
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• pp.329-337
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• 2018

This study was investigated quantitative ultrasound (QUS) usage in Korea for the QUS quality control guidelines. A total of 344 questionnaires collected from July 24th to August 25th 2017 were analyzed. Questionnaires were created through user interviews, expert group advice, literature review and field observation. As a result of the general characteristics of quantitative ultrasound holding amounted to 81.98% of clinic and 6.69% of hospitals. The main user was radio-logical technologists as 31.39%. The contact methods of the gel pad (balloon) were the most used at 56.68% and the scan region was 91.9% of calcaneus. The quantitative ultrasound quality control cycle was 67.37% when the abnormality was found in the equipment, and 63.66% when the accuracy control was implemented according to the manual. The phantoms of QUS were 34.30% of the manufacturer's own phantoms. User of QUS had never received education for quality control of quantitative ultrasound as 62.20%. This study was expected to be useful when creating detailed quality control guidelines in the future, as well as guidelines for the quality control of Korea's standard quantitative ultrasound.

• 한국전기전자재료학회논문지
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• 제29권8호
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• pp.483-488
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• 2016

Ultrasound imaging by using piezoelectric materials, such as lead zirconium titanate (PZT) has been one of the most preferred modes of imaging in the medical field due to its simple, low cost and non-ionizing radiation in comparison to other imaging techniques. Recently, the market demand for portable ultrasound is becoming larger with applications in developing countries, disaster area, military, and emergency purposes. However, most of ultrasound probes used is bulky and high power consumable, so unsuitable for such applications. In this study, the 3 layered ceramic specimen consisted of 128 pitches of $420{\mu}m$ in width and $450{\mu}m$ in thickness were prepared by using the Ti-rich PZT compositions co-fired at $1,050^{\circ}C$. Their electrical and ultrasound pulse-echo properties were investigated and compared to the single layer specimen. The 3 layered ultrasound probe showed 1.584 V of Vp-p, which is 3.2 times higher than single layered one, implying that it would allow effectively such a portable ultrasound probe system. The result were discussed in terms of higher capacitance, lower impedance and higher dielectric coefficient of the 3 layered ultrasound probe.

• IEIE Transactions on Smart Processing and Computing
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• 제3권1호
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• pp.28-34
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• 2014

Recently, ultrasound therapy has become a new and effective treatment for many brain diseases. Therefore, skull-mimicking phantoms have been developed to simulate the skull and brain tissue of a human and allow further research into ultrasound therapy. In this study, the suitability of various skull-mimicking materials(HDPE, POM C, Acrylic) for studies of brain-tumor treatments was evaluated using focused ultrasound. The acoustic properties of three synthetic resins were measured. The skull-mimicking materials were then combined with an egg white phantom to observe the differences in the ultrasound beam distortion according to the type of material. High-intensity polyethylene was found to be suitable as a skull-mimicking phantom because it had acoustic properties and a denatured-area shape that was close to those of the skull,. In this study, a skull-mimicking phantom with a multi-layer structure was produced after evaluating several skull-mimicking materials. This made it possible to predict the denaturation in a skull in relation to focused ultrasound. The development of a therapeutic protocol for a range of brain diseases will be useful in the future.

• 한국융합학회논문지
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• 제3권4호
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• pp.15-21
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• 2012

초음파 영상 진단 장치에서 획득한 데이터로부터 진단 객체를 추출하기 위한 영상 분할은 질병의 효과적인 진단을 위하여 필수적인 전처리 과정으로 인식되고 있으며, 지금까지 많은 분할 기법들이 연구되고 있다. 본 연구에서는 혈관 초음파 영상의 다양한 응용 및 진단법 개발을 위하여 기초 전처리과정으로서 graph cut 알고리즘에 의한 상호적인 영상분할법을 제시한다. 일반영상 및 혈관 초음파 영상에 대하여 전경(foreground)과 배경(background)의 제약조건을 주고 영상분할 처리하여, 원하는 object에 대한 분할 결과를 얻었다. 향후, 이러한 일련의 처리 과정이 실시간으로 처리되면 새로운 초음파 진단법으로 발전시켜 나갈 수 있을 것으로 사료된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.357-358
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• 2007

Contrast enhancement in the field of ultrasound imaging contributes to improve the accuracy of medical diagnosis by enhancing the visibility of ultrasound images. This paper proposes a contrast enhancement method that improves the contrast of ultrasound images both globally and locally by fusing global and adaptive contrast enhancement methods. Experimental results show that our approach yields more competitive results than the existing global and adaptive contrast enhancement methods in enhancing the visibility of ultrasound images.

• Journal of Yeungnam Medical Science
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• 제41권2호
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• pp.120-127
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• 2024

Background: Physiatrists are facing with survivors from disasters in both the acute and chronic phases of muscle and nerve injuries. Similar to many other clinical conditions, neuromusculoskeletal ultrasound can play a key role in the management of such cases (with various muscle/nerve injuries) as well. Accordingly, in this article, a recent single-center experience after the Turkey-Syria earthquake will be rendered. Methods: Ultrasound examinations were performed for various nerve/muscle lesions in 52 earthquake victims referred from different cities. Demographic features, type of injuries, and applied treatment procedures as well as detailed ultrasonographic findings are illustrated. Results: Of the 52 patients, 19 had incomplete peripheral nerve lesions of the brachial plexus (n=4), lumbosacral plexus (n=1), and upper and lower limbs (n=14). Conclusion: The ultrasonographic approach during disaster relief is paramount as regards subacute and chronic phases of rehabilitation. Considering technological advances (e.g., portable machines), the use of on-site ultrasound examination in the (very) early phases of disaster response also needs to be on the agenda of medical personnel.

• Korean Journal of Radiology
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• 제23권5호
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• pp.555-565
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• 2022

Objective: To assess the efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) in patients with primary hyperparathyroidism (PHPT). Materials and Methods: This prospective study enrolled 39 participants (14 male, 25 female; mean age, 59.5 ± 15.3 [range, 18-87] years) between September 1, 2018, and January 31, 2021. All participants had parathyroid lesions causing PHPT, proven biochemically and through imaging. The imaging features of the PHPT nodules, including the shape, margin, size, composition, and location, were evaluated before treatment. Serum intact parathyroid hormone, calcium, and phosphorus levels; parathyroid nodule volume; and PHPT-related symptoms were recorded before and after treatment. We calculated the technical success, biochemical cure, and clinical cure rates for these patients. Complications were evaluated during and after the ablation. Results: Complete ablation was achieved in 38 of the 39 nodules in the 39 enrolled participants. All the patients were treated in one session. The technical success rate was 97.4% (38/39). The mean follow-up duration was 13.2 ± 4.6 (range, 6.0-24.9) months. At 6 and 12 months post-RFA, the biochemical cure rates were 82.1% (32/39) and 84.4% (27/32), respectively, and the clinical cure rates were 100% (39/39) and 96.9% (31/32), respectively. Only 2.6% (1/39) of the patients had recurrent PHPT. At 1, 3, 6, and 12 months after technically successful RFA, 44.7% (17/38), 34.3% (12/35), 15.8% (6/38), and 12.5% (4/32) of participants, respectively, had elevated eucalcemic parathyroid hormone levels. Recurrent laryngeal nerve paralysis occurred in 5.1% (2/39) of the patients, who recovered spontaneously within 1-3 months. Conclusion: US-guided RFA was effective and safe for PHPT patients. RFA may be an alternative treatment tool for patients who cannot tolerate or refuse to undergo surgery.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.355-364
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• 2018

When focusing using an ultrasonic transducer array, a main lobe is formed in the focal region of an ultrasound field, but side lobes also arise around the focal region due to the leakage. Since the side lobes cannot be completely eliminated in the focusing process, they are responsible for subsequent ultrasound image quality degradation. To improve ultrasound image quality, a signal processing strategy to reduce side lobes is definitely in demand. To this end, quantitative determination of main and side lobes is necessary. We propose a theoretically and actually error-free method of exactly discriminating and separately computing the main lobe and side lobe parts in ultrasound image by computer simulation. We refer to images constructed using the main and side lobe signals as the main and side lobe images, respectively. Since the main and side lobe images exactly represent their main and side lobe components, respectively, they can be used to evaluate ultrasound image quality. Defining the average brightness of the main and side lobe images, the conventional to side lobe image ratio, and the main to side lobe image ratio as image quality metrics, we can evaluate image characteristics in speckle images. The proposed method is also applied in assessing the performance of side lobe suppression filtering. We show that the proposed method may greatly aid in the evaluation of medical ultrasonic images using computer simulations, albeit lacking the use of actual experimental data.

• 대한방사선기술학회지:방사선기술과학
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• 제38권3호
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• pp.213-220
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• 2015

본 연구는 3차원 입체정위 유방생검술의 정확도를 알아보고, 심부침생검을 이용하여 Stereotactic biopsy과 Sonoguided biopsy의 정확도와 정밀도를 평가하고자 한다. Stereotactic QC phantom을 이용하여 실제 5개의 target 위치로 3D sterotactic machine의 정확도를 측정하고, CT장비로 Scan하여 실측을 구해 X, Y, Z의 길이의 정밀도를 비교한다. 유방조직과 유사하게 제작한 Agar power phantom을 이용하여 5개의 각기 다른 needle tip Target을 통해 3D sterotactic machine과 2D ultrasound machine의 정확도를 비교하고, Z축을 장비별로 실측하여 정밀도와 신뢰도를 비교하며, 6개의 모조병소 Target을 심어놓은 Medical application phantom으로 표적하여 육안검사와 Specimen검사를 통해 정확도를 확인하였다. Stereotactic QC phantom으로 측정한 3D sterotactic machine의 정확도는 100%였으며, CT와 비교한 정밀도는 X, Y, Z축이 모두 p>0.05로 나타났다. Agar powder phantom으로 측정한 두 장비의 정확도는 100%의 정확도를 보였으며, CT와 두 장비 사이에는 p > 0.05로 차이가 없었다. 그러나 2명의 방사선사가 측정한 신뢰도분석에서 3D sterotactic machine은 ICC가 0.954였고, 2D ultrasound machine은 0.785로 2D ultrasound machine이 술자에 따라 차이가 있었다. Medical application phantom의 실험에서 3D sterotactic machine은 Sliced boneless ham을, 2D ultrasound machine은 small chalk powder group를 찾을 수 없었다. Phantom을 이용한 3차원 입체정위 유방생검술의 정확성은 우수하게 나타났고, 인체조직과 비슷한 Agar powder phantom과 유방 조직과 비슷한 Medical application phantom을 이용하여 Stereotactic biopsy과 Sonoguided biopsy의 정확도와 정밀도 모두 우수하게 나타났다. 또한 Medical application phantom의 심부침생검의 정확성 평가에서 각 검사에 따라 생검 표본이 병소의 형태에 따라 상이하게 채취되었고, 3차원 입체정위 유방생검술의 재현성이 유방 초음파검사보다 술자의 영향없이 우수하였다.

• 대한방사선협회지
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• 제27권2호
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• pp.157-174
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• 2001

Ⅰ. Purpose : To evaluate the usefulness of ultrasound-guided, radiologic placement of tunneled hemodialysis catheters via internal jugular vein(IJV). Ⅱ. Materials and Methods : In 32 patients(31 chronic renal failure, 1 acute renal failure), We performed