• 제목/요약/키워드: Contrast correction

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Surgical Correction of Congenital Type III Atresia ani with Rectovaginal Fistula in a Cat (고양이의 직장질루가 병발한 Type III 선천성 항문무형성증의 수술적 교정)

  • Kim, Minkyung;Hwang, Yong-Hyun;Choi, Woo;Lee, Jae-Hoon
    • Journal of Veterinary Clinics
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    • v.30 no.5
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    • pp.376-379
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    • 2013
  • A four-week-old female Scottish Fold cat weighting 0.6 kg was admitted for vaccination. During the physical examination, the liquid feces were observed from the vulva and the anus was imperforate. The location of a narrow fistula and distended colon were identified on the contrast radiography. Definitive diagnosis was made as type III atresia ani with rectovaginal fistula. Anal reconstruction and ligation of the fistula were successfully undertaken to treat atresia ani. After surgery, the cat was treated with lactulose and a special diet consisting of high fiber was fed to increase digestibility. The cat was able to control defecation after 2 weeks post-operation. There was no complication for 8 months after surgery.

Flexible Background-Texture Analysis for Coronary Artery Extraction Based on Digital Subtraction Angiography (유동적인 배경 텍스쳐 분석을 통한 DSA 기반의 관상동맥 검출)

  • Park Sung-Ho;Lee Joong-Jae;Lee Geun-Soo;Kim Gye-Young
    • The KIPS Transactions:PartB
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    • v.12B no.5 s.101
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    • pp.543-552
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    • 2005
  • This paper proposes the extraction of coronary arteries based on DSA(Digital Subtraction Angiography) through a texture analysis of background in the angiography. DSA is a well established modality for the visualization of coronary arteries. DSA involves the subtraction of a mask image - an image of the heart before injection of contrast medium - from live image. However, this technique is sensitive to the movement of background and can result to a wrong detection by the variance of background gray-level intensity between two images. Therefore, this paper solves a structural problem resulted from a background movement bV selecting an image which has the least difference of movement through an analysis of the similarity of background texture and proposes a method to extract only the blood vessel efficiently through local gray-level correction of the selected image. Using the coronary angiogram of 5 patients clinical data, we proved that the proposed method has the lower false-detection rate, approximately $2\%$, and the higher accuracy than the existing methods.

Surgical Correction of Congenital Peritoneopericardial Diaphragmatic Hernia with Adhered Hepatic Lobes and Cholecystitis (간엽유착과 담낭염을 동반한 선천성 복막심낭 횡격막 허니아의 효과적 수술처치)

  • Nam, Hyun-Suk;Kwak, Ho-Hyun;Lee, Se-Ho;Park, Kyung-Mee;Park, In-Chul;Han, Jeong-Hee;Woo, Heung-Myong
    • Journal of Veterinary Clinics
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    • v.29 no.1
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    • pp.87-92
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    • 2012
  • A six months old, male Shih Tzu dog was referred to the Veterinary Medical Teaching Hospital at Kangwon National University, for lethargy, respiratory embarrassment. Survey radiography revealed enlarged cardiac silhouette due to displacement of gas-filled intestine in the pericardium. Although there were no specific clinical signs, this case was diagnosed as peritoneopericardial diaphragmatic hernia (PPDH) based on the results of positive contrast radiography and thoracic ultrasonograpic findings. In addition, the thickened gall bladder wall observed in ultrasonography, increase of alkaline phosphatase and neutrophils indicated cholecystitis. Two hepatic lobes and gall bladder were severely necrotized and adhere to the diaphragm. Direct reduction of the herniated organs might cause hepatic hemorrhage and bile juice leakage which may induce very poor prognosis. To solve the problems, the adhered organs were dissected with part of diaphragm, and lobectomy with cholecystectomy was performed for prevention of some possible complications including peritonitis. This is case report describing resection of part of diaphragm adhered to herniated organ reduce the risk of possible hepatic hemorrhage during surgical correction of PPDH followed bycholecystectomy and lobectomy.

Analyses of Salinity Unit in the Secondary School Science Textbook and Suggestion for Its Correction (중등 과학교과서에서 사용된 염분 단위 분석 및 단위 개정을 위한 제안)

  • Park, Kyung-Ae;Choi, Ji-Young
    • Journal of the Korean earth science society
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    • v.30 no.4
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    • pp.513-526
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    • 2009
  • It has long been that the unit of oceanic salinity changed from permil (%o) to other unit. However, the middle-and high- school textbooks of science and earth science have still used %o as salinity unit that was defined a long time ago. The objectives of this study are to briefly discuss about the historical development of change in salinity unit and measurement techniques, to present differences between the salinity units of psu (practical salinity unit) and %o, and to address the need and validity for the correction of salinity unit in the textbooks. Twenty-seven kinds of textbooks based on the 7th National Curriculum were analyzed to investigate the expression of salinity unit and the definition of salinity. The results were compared with the usage of salinity units in the articles published in Journal of Korean Society of Oceanography from 1967 to 2008. The percentages by the use of %o were 96.3% in the text and 83.8% in the graphs or tables of the textbooks. By contrast, the scientific papers began to use psu from 1994 and then %o has seldom been used since 2004.

Mastectomy in female-to-male transgender patients: A single-center 24-year retrospective analysis

  • Kuhn, Shafreena;Keval, Seirah;Sader, Robert;Kuenzlen, Lara;Kiehlmann, Marcus;Djedovic, Gabriel;Bozkurt, Ahmet;Rieger, Ulrich Michael
    • Archives of Plastic Surgery
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    • v.46 no.5
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    • pp.433-440
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    • 2019
  • Background Mastectomy in male transgender patients is an important (and often the first) step toward physical manhood. At our department, mastectomies in transgender patients have been performed for several decades. Methods Recorded data were collected and analyzed for all male transgender patients undergoing mastectomy over a period of 24 years at our department. Results In total, 268 gender-reassigning mastectomies were performed. Several different mastectomy techniques (areolar incision, n=172; sub-mammary incision, n=96) were used according to patients' habitus and breast features. Corresponding to algorithms presented in the current literature, certain breast qualities were matched with a particular mastectomy technique. Overall, small breasts with marginal ptosis and good skin elasticity allowed small areolar incisions as a method of access for glandular removal. In contrast, large breasts and those with heavy ptosis or poor skin elasticity often required larger incisions for breast amputation. The secondary correction rate (38%) was high for gender reassignment mastectomy, as is also reflected by data in the current literature. Secondary correction frequently involved revision of chest wall recontouring, suggesting inadequate removal of the mammary tissue, as well as scar revision, which may reflect intense traction during wound healing (36%). Secondary corrections were performed more often after using small areolar incision techniques (48%) than after using large sub-mammary incisions (21%). Conclusions Choosing the suitable mastectomy technique for each patient requires careful individual evaluation of breast features such as size, degree of ptosis, and skin elasticity in order to maximize patient satisfaction and minimize secondary revisions.

The importance of corner sharpness in the BARC test case: A numerical study

  • Chiarini, Alessandro;Quadrio, Maurizio
    • Wind and Structures
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    • v.34 no.1
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    • pp.43-58
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    • 2022
  • The BARC flow is studied via Direct Numerical Simulation at a relatively low turbulent Reynolds number, with focus on the geometrical representation of the leading-edge (LE) corners. The study contributes to further our understanding of the discrepancies between existing numerical and experimental BARC data. In a first part, rounded LE corners with small curvature radii are considered. Results show that a small amount of rounding does not lead to abrupt changes of the mean fields, but that the effects increase with the curvature radius. The shear layer separates from the rounded LE at a lower angle, which reduces the size of the main recirculating region over the cylinder side. In contrast, the longitudinal size of the recirculating region behind the trailing edge (TE) increases, as the TE shear layer is accelerated. The effect of the curvature radii on the turbulent kinetic energy and on its production, dissipation and transport are addressed. The present results should be contrasted with the recent work of Rocchio et al. (2020), who found via implicit Large-Eddy Simulations at larger Reynolds numbers that even a small curvature radius leads to significant changes of the mean flow. In a second part, the LE corners are fully sharp and the exact analytical solution of the Stokes problem in the neighbourhood of the corners is used to locally restore the solution accuracy degraded by the singularity. Changes in the mean flow reveal that the analytical correction leads to streamlines that better follow the corners. The flow separates from the LE with a lower angle, resulting in a slightly smaller recirculating region. The corner-correction approach is valuable in general, and is expected to help developing high-quality numerical simulations at the high Reynolds numbers typical of the experiments with reasonable meshing requirements.

Optimization of image reconstruction method for dual-particle time-encode imager through adaptive response correction

  • Dong Zhao;Wenbao Jia;Daqian Hei;Can Cheng;Wei Cheng;Xuwen Liang;Ji Li
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1587-1592
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    • 2023
  • Time-encoded imagers (TEI) are important class of instruments to search for potential radioactive sources to prevent illicit transportation and trafficking of nuclear materials and other radioactive sources. The energy of the radiation cannot be known in advance due to the type and shielding of source is unknown in practice. However, the response function of the time-encoded imagers is related to the energy of neutrons or gamma-rays. An improved image reconstruction method based on MLEM was proposed to correct for the energy induced response difference. In this method, the count vector versus time was first smoothed. Then, the preset response function was adaptively corrected according to the measured counts. Finally, the smoothed count vector and corrected response were used in MLEM to reconstruct the source distribution. A one-dimensional dual-particle time-encode imager was developed and used to verify the improved method through imaging an Am-Be neutron source. The improvement of this method was demonstrated by the image reconstruction results. For gamma-ray and neutron images, the angular resolution improved by 17.2% and 7.0%; the contrast-to-noise ratio improved by 58.7% and 14.9%; the signal-to-noise ratio improved by 36.3% and 11.7%, respectively.

Assessment of Attenuation Correction Techniques with a $^{137}Cs$ Point Source ($^{137}Cs$ 점선원을 이용한 감쇠 보정기법들의 평가)

  • Bong, Jung-Kyun;Kim, Hee-Joung;Son, Hye-Kyoung;Park, Yun-Young;Park, Hae-Joung;Yun, Mi-Jin;Lee, Jong-Doo;Jung, Hae-Jo
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.1
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    • pp.57-68
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    • 2005
  • Purpose: The objective of this study was to assess attenuation correction algorithms with the $^{137}Cs$ point source for the brain positron omission tomography (PET) imaging process. Materials & Methods: Four different types of phantoms were used in this study for testing various types of the attenuation correction techniques. Transmission data of a $^{137}Cs$ point source were acquired after infusing the emission source into phantoms and then the emission data were subsequently acquired in 3D acquisition mode. Scatter corrections were performed with a background tail-fitting algorithm. Emission data were then reconstructed using iterative reconstruction method with a measured (MAC), elliptical (ELAC), segmented (SAC) and remapping (RAC) attenuation correction, respectively. Reconstructed images were then both qualitatively and quantitatively assessed. In addition, reconstructed images of a normal subject were assessed by nuclear medicine physicians. Subtracted images were also compared. Results: ELEC, SAC, and RAC provided a uniform phantom image with less noise for a cylindrical phantom. In contrast, a decrease in intensity at the central portion of the attenuation map was noticed at the result of the MAC. Reconstructed images of Jaszack and Hoffan phantoms presented better quality with RAC and SAC. The attenuation of a skull on images of the normal subject was clearly noticed and the attenuation correction without considering the attenuation of the skull resulted in artificial defects on images of the brain. Conclusion: the complicated and improved attenuation correction methods were needed to obtain the better accuracy of the quantitative brain PET images.

A High-performance Lane Recognition Algorithm Using Word Descriptors and A Selective Hough Transform Algorithm with Four-channel ROI (다중 ROI에서 영상 화질 표준화 및 선택적 허프 변환 알고리즘을 통한 고성능의 차선 인식 알고리즘)

  • Cho, Jae-Hyun;Jang, Young-Min;Cho, Sang-Bok
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.2
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    • pp.148-161
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    • 2015
  • The examples that used camera in the vehicle is increasing with the growth of the automotive market, and the importance of the image processing technique is expanding. In particular, the Lane Departure Warning System (LDWS) and related technologies are under development in various fields. In this paper, in order to improve the lane recognition rate more than the conventional method, we extract a Normalized Luminance Descriptor value and a Normalized Contrast Descriptor value, and adjust image gamma values to modulate Normalized Image Quality by using the correlation between the extracted two values. Then, we apply the Hough transform using the optimized accumulator cells to the four-channel ROI. The proposed algorithm was verified in 27 frame/sec and $640{\times}480$ resolution. As a result, Lane recognition rate was higher than the average 97% in day, night, and late-night road environments. The proposed method also shows successful lane recognition in sections with curves or many lane boundary.

Color Improvement of Retinex Image Using the Maximum Color Difference Signal Table (최대 색차신호 표를 이용한 Retinex 영상의 컬러 향상)

  • Lee, Jae-Won;Jung, Jee-Hoon;Hong, Sung-Hoon
    • Journal of Broadcast Engineering
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    • v.17 no.5
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    • pp.851-863
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    • 2012
  • Retinex algorithm enhances the contrast of image through visibility improvement. However, the conventional Retinex methods may produces color distortions due to error of hue representation and over-saturation since the methods work in RGB color space. In this paper, we propose a new Retinex algorithm with color correction, which improves contrast by using MSR(Multi-Scale Retinex) working in YCbCr color space and adaptively compensates the color saturation based on the maximum color difference table. Our algorithm maps the color difference signals to the correct gamut to prevent over-saturation phenomenon by considering the correlation between luminance and hue dependent saturation. Simulations results show that the proposed method gives better color improvement compared to the conventional methods.