• Imaging Science in Dentistry
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• 제48권3호
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• pp.161-165
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• 2018

Purpose: To evaluate the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Materials and Methods: Ten patients with oral and maxillofacial diseases and 28 volunteers drawn from our student doctors were examined by shear wave elastography with a 14-MHz linear transducer using an Aplio 300 apparatus (Canon Medical Systems, Otawara, Japan). A statistical analysis of the shear elastic modulus(kPa) of healthy tissue (the sublingual gland, submandibular gland, anterior belly of the digastric muscle, and geniohyoid muscle) in the 28 volunteers was performed using 1-way repeated measures analysis of variance with the Tukey honest significant difference test. The maximum shear elastic modulus(kPa) of 8 patients with squamous cell carcinoma (SCC) and 2 patients with benign lesions was evaluated with the Mann-Whitney U test. The analysis used a 5% significance level. Results: The mean shear elastic modulus of the sublingual gland ($9.4{\pm}3.7kPa$) was lower than that of the geniohyoid muscle ($19.2{\pm}9.2kPa$, P=.000) and the anterior belly of the digastric muscle ($15.3{\pm}6.1kPa$, P=.004). The maximum shear elastic modulus of the SCCs($109.6{\pm}14.4kPa$) was higher than that of the benign lesions($46.4{\pm}26.8kPa$, P=.044). Conclusion: Our results demonstrated the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Shear wave elastography has the potential to be an effective technique for the objective and quantitative diagnosis of oral and maxillofacial diseases.

• 한국방사선학회논문지
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• 제17권7호
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• pp.1057-1065
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• 2023

비침습적 간섬유화 진단은 만성 간질환 환자들에게 매우 중요한 사항이다. 많은 환자들에게 간조직검사를 시행할 수가 없기 때문에 의미 있는 간섬유화 정도를 조기에 예측함으로써 만성 간질환의 치료와 간세포암 및 간경변증으로 인한 합병증을 감소시킬 수 있다. 본 연구는 비침습적인 간섬유화 검사 방법 중 간초음파 소견과 함께 전단파 탄성 초음파를 이용하여 간섬유화의 정량적 측정과 간탄성도 수치와 연관성을 갖는 혈청학적 인자도 비교 분석하였다(p<0.05). 그 결과 정상 집단의 횡파탄성측정값은 4.55 ± 0.69 kPa였으며, 에코 패턴의 비정상 대조군은 8.27 ± 1.83 kPa로 B형 간염 보균 집단에서 전단파 탄성 초음파 측정값이 높게 나타났으며, 혈청학적 인자들 중 AST, ALT, GGT, PT가 SWE 범주에 따른 섬유화의 정도에 따라 통계학적으로 유의한 양의 연관성을 보였으나(p<0.05) ALP와 TB는 통계적으로 유의미한 차이를 나타내지 않았다(p=0.163, p=0.567). 반면에 Albumin과 PLT는 유의한 음의 연관성을 보였다(p<0.05). 임상적으로 간경변 증후가 없는 만성 B형 간염 환자들의 간섬유화 추적 관찰 및 반복 검사 시 간초음파와 전단파 탄성 초음파 검사를 통한 탄성도 값을 추가로 활용한다면 검사자 간 객관적 진단에 있어 도움이될 것이며, 일차적인 진료에 유용할 것으로 사료된다.

• 한국방사선학회논문지
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• 제17권6호
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• pp.919-927
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• 2023

탄성 초음파는 양성 종괴에 비해 악성 종괴의 경우 조직이 더 단단하다는 것을 이용하여 종괴의 탄성계수에 따라 진단의 특이도를 높여주어 불필요한 조직검사를 줄이는데 도움이 되고 있다. 이러한 탄성 초음파 검사는 검사 장비나 검사자에 따라 재현성의 문제가 있을 수 있기에, 본 연구에서는 탄성 초음파 검사의 신뢰성을 확인하고자 탄성 초음파의 탄성값 반복 측정시 재현성에 관한 팬텀 영상 평가를 분석하였다. 한천과 젤라틴을 이용하여 각각 다른 강성을 가지는 3개의 모조 병소를 표면으로부터 깊이가 다르게 삽입한 팬텀을 자체 제작하여 전단파 탄성 초음파를 이용하여 탄성값을 반복 측정하였다. 병소의 강성과 깊이의 차이에 따라 측정된 탄성값의 재현성이 유지되는지를 분석해 보았다. 실험 결과 전단파 탄성 초음파의 탄성값과 병소의 깊이, 병소의 강성과 깊이는 통계적으로 유의할 만큼 상관관계를 나타내지 않았다. 하지만 강성이 가장 낮은 모조 병소에서는 병소의 깊이에 따라 탄성값은 p<0.001으로 통계적으로 유의했고 높은 상관관계를 보였다. 병소의 강성과 깊이의 차이에 따라 전단파 탄성초음파의 탄성값의 반복 측정시 측정값의 차이는 발생하지만, 진단에 영향을 주지 않는 수준이므로 전단파 탄성초음파 검사는 신뢰할 수 있는 검사방법이기에 유방 결절의 진단에 있어서 전단파 탄성초음파 검사가 도움이 될 것으로 사료된다.

• Journal of Veterinary Science
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• 제22권1호
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• pp.3.1-3.13
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• 2021

Background: Multifidus muscle stiffness decreases in patients with lumbar intervertebral disk herniation; however, age-related changes in humans have not been reported. Objectives: The reliability of ultrasound shear wave elastography in dogs, and changes in the shear elastic modulus of the thoracolumbar multifidus muscle with aging in dogs, were investigated. Methods: Twelve beagle dogs were divided into 2 groups based on the age of onset of intervertebral disk herniation: young (aged not exceeding 2 years; 1.3 ± 0.6 years old, n = 5) and adult (4.9 ± 1.2 years old, n = 7). The shear elastic modulus of the multifidus muscle, from the thirteenth thoracic spine to the fourth lumbar spine, was measured using ultrasound shear wave elastography. The length, cross-sectional area and muscle to fat ratio of the multifidus muscle, and the grade of intervertebral disk degeneration, were assessed using radiographic and magnetic resonance imaging examinations. Results: The length and cross-sectional area of the multifidus muscle increased caudally. In the young group, the shear elastic modulus of the multifidus muscle of the thirteenth thoracic spine was less than that of the third lumbar spine. In the adult group, the shear elastic modulus of the multifidus muscle of first and third lumbar spine was lower than that of the same site in the young group. Conclusions: Ultrasound can be used to measure shear wave elastography of the thoracolumbar multifidus in dogs. If the multifidus muscle stiffness decreases, we should consider age-related change.

• 대한의용생체공학회:의공학회지
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• 제33권1호
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• pp.32-38
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• 2012

Recently, several ultrasound imaging techniques for tissue characterization have been developed. Among them, ultrasound elastography is regarded as the most promising modality and has been rapidly developed. One of ultrasound elastography techniques is shear modulus imaging. Normal and cancerous tissues show big difference of shear moduli and they have good image contrast. However shear wave elastography requires more complicated hardware and more computations for image reconstruction algorithm. Therefore new efficient techniques are being developed. In this paper, we have developed a very flexible ultrasound system for elastography experiments. The developed system has capabilities to acquire ultrasound RF data of all channels and generate arbitrary ultrasound pulse sequences. It has a huge amount of memories for RF data acquisition and a simple and flexible pulse generator. We have verified the performance of the system showing conventional B-mode images and preliminary results of elastography. The developed system will be used to verify our own reconstruction algorithm and to develop more efficient elastography techniques.

• 대한방사선기술학회지:방사선기술과학
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• 제45권4호
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• pp.341-346
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• 2022

The color overlay pattern of thyroid shear wave elastography applied in this study distinguishes benign and malignant nodules based on the optimal cut-off value of 74.2 kPa. From august 2021 to september 2021, thyroid ultrasound and elastography were performed on 57 patients with thyroid lesions using an ultrasound device RS85 prestige (Samsung Medison, Korea) and a 2-14 MHz linear transducer. In addition, the results of classification by K-TIRADS for each thyroid nodule and the results of classification by color overlay pattern according to the kPa value of acoustic ultrasound were compared and analyzed. In the color overlay pattern, the results classified as 40 people from dark blue to light blue and 17 people from green to red were similar to the K-TIRADS category results, which were classified as 42 benign and 15 malignant. Between blue and light blue, benign, and between green and red, malignant. If the shear wave elastography method is applied before the fine-needle aspiration cytology of the thyroid nodule is performed, the differential diagnosis of thyroid tissue from benign and malignant can be predicted in advance, and it will help to reduce unnecessary invasive tests.

• 한국방사선학회논문지
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• 제15권6호
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• pp.883-889
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• 2021

본 연구는 2020년 5월부터 2020년 12월까지 복부초음파 검사를 위해 내원한 101명의 환자를 대상으로 하였다. 횡파탄성측정검사법을 이용하여 초음파 검사 시 초음파 영상(에코 패턴, 비장비대, 간염) 소견에 따른 탄성도를 알아 알아보고자 하였다. 에코 패턴의 정상 그룹의 횡파탄성측정값은 5.75±1.58 kPa였으며, 에코 패턴의 비정상 그룹은 8.84±4.94 kPa로 에코 패턴 비정상 그룹에서 횡파탄성측정값이 높게 나타났다(p<0.05). 정상 비장 크기에서 간 탄성도 값은 6.33±2.54 kPa였으며, 비장비대의 간 탄성도 값은 13.73±5.48 kPa로 나타났다. 비장비대일 경우 간 탄성도 값이 높게 나타났으며, 통계적으로 유의미한 차이가 있었다(p<0.05). 비장 크기가 증가할수록 간 탄성도 값이 1.485배, 간염이 진행될수록 간 탄성도 값이 1.573배 증가하는 것으로 나타났다(p<0.05). 초음파 영상 소견과 횡파탄성측정법 간 일치도 분석 결과 Kappa 값이 0.922(p<0.05)로 높게 나타났으며, 두 검사 방법 간에 높은 일치도를 보였다. 간 초음파 소견과 함께 횡파탄성측정법 검사의 간 탄성도 값을 추가적으로 비교한다면 간 섬유화 진단에 있어 많은 도움이 될 것으로 생각된다.

• Clinical Endoscopy
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• 제56권2호
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• pp.229-238
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• 2023

Background/Aims: Shear wave elastography (SWE) is used for liver fibrosis staging based on stiffness measurements. It can be performed using endoscopic ultrasound (EUS) or a transabdominal approach. Transabdominal accuracy can be limited in patients with obesity because of the thick abdomen. Theoretically, EUS-SWE overcomes this limitation by internally assessing the liver. We aimed to define the optimal technique for EUS-SWE for future research and clinical use and compare its accuracy with that of transabdominal SWE. Methods: Benchtop study: A standardized phantom model was used. The compared variables included the region of interest (ROI) size, depth, and orientation and transducer pressure. Porcine study: Phantom models with varying stiffness values were surgically implanted between the hepatic lobes. Results: For EUS-SWE, a larger ROI size of 1.5 cm and a smaller ROI depth of 1 cm demonstrated a significantly higher accuracy. For transabdominal SWE, the ROI size was nonadjustable, and the optimal ROI depth ranged from 2 to 4 cm. The transducer pressure and ROI orientation did not significantly affect the accuracy. There were no significant differences in the accuracy between transabdominal SWE and EUS-SWE in the animal model. The variability among the operators was more pronounced for the higher stiffness values. Small lesion measurements were accurate only when the ROI was entirely situated within the lesion. Conclusions: We defined the optimal viewing windows for EUS-SWE and transabdominal SWE. The accuracy was comparable in the non-obese porcine model. EUS-SWE may have a higher utility for evaluating small lesions than transabdominal SWE.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권3호
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• pp.282-290
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• 2019

Characterizing inflammation and fibrosis in Crohn's disease (CD) is necessary to guide clinical management, but distinguishing the two remains challenging. Novel ultrasound (US) techniques: contrast-enhanced US (CEUS) and shear wave elastography (SWE) offer great potential in evaluating disease activity in pediatric patients. Three patients ages 16 to 20 with known CD underwent CEUS and SWE to characterize bowel wall inflammation and fibrosis. Magnetic resonance enterography, endoscopy, or surgical pathology findings are also described when available. The patients' disease activity included acute inflammation, chronic inflammation with stricture formation, and a fibrotic surgical anastomosis without inflammation. CEUS was useful in determining the degree of inflammation, and SWE identified bowel wall fibrosis. Used together these techniques allow for better characterization of the degree of fibrosis and inflammation in bowel strictures. With further validation CEUS and SWE may allow for improved characterization of bowel strictures and disease flares in pediatric patients suffering from CD.

• Journal of Veterinary Science
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• 제24권6호
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• pp.75.1-75.8
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• 2023

Background: In veterinary medicine, previous studies regarding the diagnostic performance of shear wave elastography (SWE) in chronic kidney disease (CKD) are not consistent with each other. Moreover, there has been no study evaluating the relationship between symmetric dimethylarginine (SDMA) concentration and renal shear wave velocity (SWV) using two-dimensional SWE (2D SWE) in dogs with CKD. Objectives: This study aimed to evaluate the diagnostic capability of 2D SWE in dogs with CKD and to assess the relationship between renal SWV and SDMA concentration. Methods: Dogs with healthy kidneys and dogs with CKD underwent 2D SWE and SDMA assay. Renal stiffness was estimated as renal SWV in m/s. Results: SDMA concentration had a weak positive correlation with the left (r = 0.338, p = 0.022) and right renal SWV (r = 0.337, p = 0.044). Renal SWV was not significantly different between healthy kidney and CKD groups in the left (p = 0.085) and right (p = 0.171) kidneys. Conclusions: 2D SWE may could not distinguish between dogs with healthy kidney and dogs with early stage of CKD, but it would be useful for assessing the serial change of renal function in dogs.