• The Journal of the Korea Contents Association
• /
• v.16 no.10
• /
• pp.291-298
• /
• 2016

The aim of the study was to investigate the diagnostic value of the color Doppler twinkling artifact in disease of urinary system. The intensity of twinkling artifact(TA) with color Doppler was classified into 3 levels, 0(non-TA) to 3(distinct TA). In the in vitro study, acorn jelly with various materials on top was examined using color Doppler at B-mode sonography in a water bath for TA. 31 patients with diagnosis of urinary calculi(renal stones 16, urinary stones 15) based on B-mode sonography were studied in vivo for TA. The materials with rough surfaces such as salt, screw and cubics at B-mode sonography with color Doppler contributed to causing TA. At B-mode sonography without color Doppler 37% of renal stones and 60% of ureter stones were detected. but at B-mode sonography with color Doppler TA was demonstrated for all cases. Superficial roughness of materials affected occurrence of TA at B-mode sonography with color Doppler. Therefore, TA at B-mode sonography without color Doppler could play a role in confident diagnosis of the disease of urinary system.

• The Journal of the Korea Contents Association
• /
• v.17 no.1
• /
• pp.120-128
• /
• 2017

Acute flank pain from urolithiasis is the most common condition in people visiting emergency rooms. This study is to evaluate the usefulness of color Doppler in detecting ureteral stones in patients without hydronephrosis. We performed ultrasonography and retrospective analysis on 161 patients who were suspected of urinary stones through plain radiography of the kidney, ureter, and bladder examination or urine tests that showed positive signs of hematuria. In ultrasonography, a total of 154 (95.6%) cases from the 161 patients were diagnosed with ureteral stones. In color Doppler, ureteral stones with twinkling artifact (TA) in the absence of hydronephrosis was shown in 18 (85.7%) cases of the 21 patients(p<0.001). The use of color Doppler has a high diagnostic efficacy for the detection of indistinguishable stones, non-dilatational ureteral stones, and middle ureter stones.

• Journal of Veterinary Clinics
• /
• v.20 no.2
• /
• pp.145-149
• /
• 2003

Color Doppler imaging(CDI) was carried out to determine CDI-derived resistive index(RI) values of normal canine ophthalmic vasculature and its reproducibility. CDI was performed on 58 dogs. and normal ranges of RI value were calculated for the medial long posterior ciliary artery(mLPCA), ciliary artery(CA), and ophthalmic artery(OA). Ophthalmic vascular RI values of normal dogs were 0.67$\pm$0.07, 0.70$\pm$0.06, and 0.80$\pm$0.04 in mLPCA, CA, and OA, respectively. Means of RT value of all vessel had no statistically significant difference by sex, fellow orbits, and skull type. The results suggest that color Doppler imaging is a noninvasive test which has the advantage of providing objective measurements of blood flow velocity parameter in the canine eye and orbit.

• Journal of the Korean Society of Radiology
• /
• v.18 no.2
• /
• pp.83-91
• /
• 2024

The purpose of this study was to determine the doppler fluid effects of carbonated water (CBW) in a bi-directional flow phantom model. A bi-directional flow phantom model was chosen to realize arterial and venous flow, and the structure of the inner and outer tanks allowed for fluid circulation and also made the size of the phantom small. Carbonated water (CBW), salt fluid (SAF), sugar fluid (SUF), and distilled water (DW) were used as fluids, and ultrasound scans were performed at depths of 1.5 cm and 3.0 cm from the surface of the tank, using B-mode and color Doppler effects. All fluids tested showed color Doppler effects, but CBW had the highest doppler shift and the least variation with depth. In conclusion, we determined that CBW was the most suitable fluid to be used as a doppler fluid and confirmed that the bubbles dissolved in CBW act as doppler scatterers, just like red blood cells inside human blood. Therefore, it is possible that CBW can be used as a blood-mimicking fluid in doppler ultrasound phantoms through further research, and this study will provide basic data.

• Journal of radiological science and technology
• /
• v.38 no.4
• /
• pp.443-449
• /
• 2015

An ultrasound probe has a big impact on Doppler images even though it has very high risk of frequent function-breakdowns occurring in medical ultrasound scanners. This study experimentally analyses the impacts of an ultrasonic probe's defected elements on power & color Doppler images. The results show that, the bigger the size of defected probe elements is, and the closer a group of action elements is to the center, the more the brightness of images and the velocity of Doppler diminish. When elements' defects increase in color & power Doppler images, false images are formed to be mistaken for blood-vessel plaque in neighboring regions. Accordingly, whenever element defects are suspected, we need check-up process in B-mode. From this respective, it is advisable to have primary interest in a probe and carry out continuous probe QA for ultrasonography.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.5
• /
• pp.2261-2266
• /
• 2011

Being the most widely used in ultrasound Doppler color flow mapping, the Kasai algorithm, also known as lag-1 autocorrelation method, is capable of estimating the Doppler mean frequency relatively accurately with a modest amount of computation. Particularly in the case of imaging deep lying areas, however, its performance suffers due to low signal-to-noise ratios. The purpose of this paper is to propose a dealiased lag-2 autocorrelation method which is superior to the Kasai algorithm even at low signal-to-noise ratios and to compare their performances through simulations. The proposed algorithm is found to be better by about 2 to 3 dB than the Kasai algorithm in terms of Doppler mean frequency estimation error in the presence of measurement noise.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.6 no.1
• /
• pp.10-14
• /
• 2013

Pilomatricoma is a benign skin tumor that develops from hair matrix cells. It most commonly occurs in the head and neck, followed by the upper extremities. Accuracy of preoperative diagnosis was low in previous studies and excisional biopsy was even performed frequently without imaging studies. We report a case of pilomatricoma of the shoulder that was easily diagnosed by ultrasound including color Doppler, which is a more useful imaging modality than computed tomography or magnetic resonance imaging scans not only because of its cost effectiveness but also because of the precise information obtained from mass contents.

• Clinical and Experimental Pediatrics
• /
• v.45 no.4
• /
• pp.489-497
• /
• 2002

Purpose : The objectives of this study were to investigate the causes of chronic cough and to establish the appropriate diagnostic approach to chronic cough in children. Methods : One hundred and thirty two cases of chronic cough were prospectively evaluated. They visitors to pediatric chronic cough clinics at Kang-nam saint Mary's Hospital of Catholic University from August 2000 to July 2001 for 12 months. Careful history taking by questionnaire, physical examination, radiologic studies of chest and sinus, hematologic and immunologic studies, allergic skin tests, and methacholine challenge tests were performed. Color doppler(CD) ultrasonography were performed and compared with simultaneous 24 Hr. esophageal pH monitoring to diagnose gastroesophageal reflux disease(GERD). Results : Age distributions were demonstrated that nine in infants, 82 in early childhood, 38 in late childhood, and three in adolescence. Common causes of chronic cough were bronchial asthma in 40 cases, chronic sinusitis in 22 cases, GERD in seven cases, bronchial asthma combined with sinusitis in 28 cases, bronchial asthma combined with GERD in 14 cases, psychogenic cough in two. cases, foreign body in one case, chronic bronchitis in one case, and bronchiolitis in one case. Comparing with 24 Hr. pH monitoring, sensitivity, specificity, positive predictive value and negative predictive values of CD ultrasonography were 88%, 69%, 85 %, and 73% respectively. Conclusion : The most common causes of chronic cough in children were bronchial asthma, sinusitis and GERD in order. We suggest that CD ultrasonography can be used as a good, convenient screening method for patients with suspected GERD in outpatient settings.

• Journal of the Korean Society of Radiology
• /
• v.17 no.7
• /
• pp.1049-1055
• /
• 2023

The purpose of this study was to investigate the association of twinkling artifacts according to the types of urinary stones in color Doppler ultrasound. For two types of urinary stones with different colors, the degree of occurrence of color Doppler twinkling artifact in water tank was analyzed, and the surface condition and composition of the stones were analyzed. The composition of Calcium and phosphorus were the most frequent components in white and brown stones excluding carbon and oxygen. Twinkling artifacts of color Doppler appear stronger in brown stone. The higher the phosphorus content of the stones, the shorter the twinkling artifact appears, so it is possible to predict the main composition of stones.

• Journal of the Korean Society of Radiology
• /
• v.17 no.5
• /
• pp.751-759
• /
• 2023

Breast ultrasonography is difficult to image in fatty breasts and to find micro-calcification, but the discovery of micro-calcification is very important for breast cancer screening. Among the color Doppler artifact of ultrasound, twinkle artifact mainly occur on strong reflectors such as stones or calcification in images, and evaluation methods using them are clinically being used. In this study, we are conducting experiments on the color Doppler settings of ultrasound equipment, such as repetition frequency, ensemble, persist, wall filtering, smoothing, linear density, and dissociation value, by producing a breast simulation phantom using the largest amount of calcium phosphate among breast implants. The purpose of this study was to improve the contrast of twinkle artifact in breast ultrasound examinations and to maximize their use in clinical practice. As a result, the pulse repetition frequency occurred in the range of 3.6 kHz to 7.2 kHz, and did not occur above 10.5 kHz. For ensembles, twinkle artifact occurred in all sizes of calcification under low conditions, and in threshold settings, the twinkle artifact increased slightly only under 80 to 100 conditions, and did not occur in 1 mm size calcification. Persist, wall filter, smoothing, and line density settings did not have much meaning in the setting variable because conditions did not increase by condition, and pulse repetition frequency, ensemble, and thresholds had the greatest impact on the twinkling artifact image. This study is expected to help examiners select optimal conditions to effectively increase twinkle artifact by adjusting color Doppler settings.