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Yong-whee Bahk - One of the best experts on this subject based on the ideXlab platform.
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Miscellanea of Gamma Correction Medical Imaging
Imaging of Trabecular Microfracture and Bone Marrow Edema and Hemorrhage, 2020Co-Authors: Yong-whee BahkAbstract:Bone marrow edema (BME), bone marrow hemorrhage (BMH) and trabecular microfracture (TMF) are the essential triad of alive marrow bone changes, which homeostatically occur in trauma, sports injuries, osteoporosis, inflammation, infection, neoplasm, and even in daily physical activities and works (Salcianu et al. 2014). Such a phenomenon betokens that bone is insensitively yet vitally engaged with ceaseless active metabolic change to support and maintain thinking, respiration, and blood circulation in humans. Hence, the analytical differential assessment of each constituent of the triad is considered to be essential for the precise diagnosis of bone trabecular diseases at micrographic level. Fortunately, now CTMF (callused trabecular microfracture) can be clearly imaged by suppressing the blurry penumbra in BME and BMH using ACDSee-10 GCPBS (Gamma Correction pinhole bone scan) so that the triad can be precisely quantified (Fig. 16.1). Imaging wise, however, edema and hemorrhage are currently not distinguished from each other because both are equally suppressed by Gamma Correction. In order to overcome the difficulty, we adopted the mathematic categorization of 99mTc-HDP uptake values of BME and BMH using the NIH ImageJ densitometry in terms of “Arbitrary Unit (AU)” and found that there exists a significant difference between the AU values of edema and hemorrhage (Fig. 16.2). Practically, we could conveniently classify the AU of normal trabeculae to be ≤50 and AU of edema, hemorrhage, and trabecular microfracture to be 51–100, 101–150 AU, and ≥151, respectively (Bahk et al. 2019). Importantly, this classification is based on measurements of lesion size on naive pinhole bone scan before Gamma Correction. Lately, a correlative analysis of the findings of seriated naive pinhole bone scan (naive PBS) and GCPBS revealed that the diagnostic level of TMF in relation to BME and BMH is high.
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Gamma Correction 99m Tc-HDP Pinhole Bone Scan Demonstration of Callused Trabecular Microfracture
Imaging of Trabecular Microfracture and Bone Marrow Edema and Hemorrhage, 2020Co-Authors: Yong-whee BahkAbstract:Gamma Correction 99mTc-HDP pinhole bone scan can uniquely demonstrate CTMF along with bone metabolic profile. The smallest CTMF imaged on Gamma Correction pinhole bone scan measures 200 μm in size and this size is equivalent to one pixel. We carried out a seriated naive and Gamma Correction pinhole bone scan study with histological verification to fundamentally establish a morphobiochemical diagnostic basis of CTMF in six surgical specimens of femoral neck fracture. Specimens were attained from femoral neck fracture surgery performed for prosthetic replacement. After cleansing with 10% formalin solution the broken surface of the specimen was scrutinized using a surgical surface microscope to confirm that seed-pearly callused microcalluses were formed (Fig. 6.1). As the extension of the study, the surgical specimens were further imaged using 99mTc-HDP pinhole bone scan and then serially treated by Gamma Correction, earlier using ACDSee-7 version and lately using ACDSee 10 version. The former version treated image showed penumbra, but the latter version image showed no penumbra (vide infra).
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ACDSee-10 Gamma Correction MRI for Neat Imaging and Magnifying Lens Measurement of Callused Trabecular Microfracture
Imaging of Trabecular Microfracture and Bone Marrow Edema and Hemorrhage, 2020Co-Authors: Yong-whee BahkAbstract:The excelled usefulness of Gamma Correction 99mTc-HDP pinhole bone scan for the imaging and diagnosis of callused trabecular microfracture (CTMF) has been well demonstrated and discussed. Now in succession, the same principle of Gamma Correction of ACDSee-10 version is practically considered to be worthy of importing to magnetic resonance imaging (MRI) to make an in vivo demonstration of CTMF, which occurs in most bone diseases and also in normal bones. Special MRI techniques such as proton spectroscopy and multiparametry can show nearly all kinds of somatic tissues and organs, but apparently excepting trabecular microfracture. Recently, we became to realize that ACDSee-10 Gamma Correction MRI can visualize and quantitate CTMF (Vide Chap. 13). The aims of this study on ACDSee-10 Gamma Correction MRI are twofold: first is an extended application of Gamma Correction to MRI for precise, graphic diagnosis of CTMF by avoiding penumbra and second is to develop handy quantitation method in terms of the number of injured pixel simply using a magnifying lens. Technically, we imaged microfractures by seriated naive and ACDSee-10 Gamma Correction T2 weighted MRI in nine consecutive cases. The clinical materials consisted of the bones of the shoulder girdle, hip, knee, ankle, and foot. The usefulness of ACDSee-10 Gamma Correction MRI diagnosis was verified in each case by the corroboratory trabecular microfracture findings of foregone ACDSee-10 99mTc-HDP pinhole bone scan and surgical specimen as well as H&E stain. Results were that the bright MR signal intensity of microfracture was distinctly highlighted and precisely measured by the direct counting of the number of injured pixel using a magnifying optic lens. The injured micrometric pixel was characteristically presented as bright signal intensity against dark background matrix on ACDSee-10 Gamma Correction MRI, while it was conversely presented as dark microscopic 99mTc-HDP uptake against bright matrix on ACDSee 10 Gamma Correction pinhole bone scan. The latter was used to validate the former. The smallest size of the unit pixel shown in our computer screen was 200 μm in the x-axis of coordinate. ACDSee-10 Gamma Correction MRI demonstrated as many as 15 single-pixel CTMF in nine cases, but ACDSee 10 Gamma Correction pinhole bone scan showed only five single-pixel CTMF and such a difference was theoretically presumed to be due to high sensitivity of MRI. For information, the diagonal of computer monitor we used was 24 inches and screen resolution was 1920 × 1080, Samsung LS23C340, Seoul, South Korea.
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Gamma Correction 99m Tc-HDP Pinhole Bone Scan of Trabecular Microfracture and Endosteal Rimming in Rat
Imaging of Trabecular Microfracture and Bone Marrow Edema and Hemorrhage, 2020Co-Authors: Yong-whee BahkAbstract:During the recent years, we published some articles on Gamma Correction medical imaging, Gamma Correction 99mTc-HDP pinhole bone scan (GCPBS) in particular, for the specific diagnosis of callused trabecular microfracture (CTMF), bone contusion, and bone marrow edema and hemorrhage (Bahk et al. 2010, 2016, 2017, 2019). Those studies showed that the high 99mTc-HDP uptake in contused trabeculae is not suppressed by Gamma Correction, but the low uptake in intact bone trabeculae and edema and the moderate uptake in hemorrhage was cleanly suppressed. Originally, Francis et al. (1980) noted in their Sprague-Dawley rat experiment that 99mTc-HDP uptake was significantly increased in injured trabeculae because bone tracer was actively adsorbed onto amorphous calcium phosphate, which is actively engaged with osteoneogenesis in osteoblastic rimming of contused trabeculae. It was also shown that the nominal tracer uptake in intact bone and mild to moderate tracer uptake in bone edema and hemorrhage is due to loose adhesion of tracer onto crystalline hydroxyapatite. Recently, we also performed young rat experiment and confirmed the fact that the nominal tracer uptake in the normal trabeculae and mild to moderate tracer uptake (Fig. 4.1) in edema and hemorrhage are all cleanly suppressed by Gamma Correction, but the high uptake in CTMF is not suppressed at all (Fig. 4.2) (Bahk et al. 2016). To be exact the normal control study showed that the intact femur uniformly accumulates mild tracer, which is neatly suppressed by Gamma Correction barely showing endosteum on H&E stain (Fig. 4.1). Contrary, however, when trabeculae are well defined after Gamma Correction it may well denote that endosteal rimming is formed (Fig. 4.2). Unsuppressed high tracer uptake in epiphysis indicates that the physis in young rats is actively engaged with physiologically growing osteoneogenesis. The same biophysical phenomenon can be seen in CTMF, which is similarly engaged with active repair osteoneogenesis. It can be said that distinctly defined trabeculae may well be interpreted to designate endosteal rimming (Fig. 4.2).
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General Gamma Correction Pinhole Bone Scan Diagnosis
Combined Scintigraphic and Radiographic Diagnosis of Bone and Joint Diseases, 2017Co-Authors: Yong-whee BahkAbstract:Gamma Correction pinhole bone scan is a recently developed image processing algorithm that can efficiently extract fine pathoanatomical changes in a large number of bone diseases with bland uptake of 99mTc-hydroxymethylene diphosphonate (HDP) (Bahk et al., Skeletal Radiol 39:807–813, 2010; Bahk et al., Nucl Med Mol Imaging 45:21–29, 2011). This chapter discusses extended application of Gamma Correction pinhole scan to the diagnosis of various fractures, cervical sprain, whiplash injury, edema bone diseases, osteoporosis, avascular osteonecrosis, fish vertebra, noninfective osteitides, osteomyelitis, benign and malignant bone tumors, and tumorous diseases of bone.
Hassene Mnif - One of the best experts on this subject based on the ideXlab platform.
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New Gamma Correction Method for real time image text extraction
2019Co-Authors: Mohamed Amin Ben Atitallah, Rostom Kachouri, Ahmed Ben Atitallah, Hassene MnifAbstract:Text extraction and character recognition in manuscripts are a very important part of image processing and pattern recognition. The recently proposed Gamma Correction Method (GCM) is a popular method used in the processing of a color image and in particular in the extraction of text from a complex image. However, The GCM consumes a lot of time to extract the text and this is because of the complex calculations of different operations in the different blocks of GCM which is not suitable to real-time applications. In this paper, we propose an efficient Gamma Correction Method acceleration. Our proposal allows to minimize the GCM execution time while ensuring the same reliability of the initial version. The experimental results show an important optimization compared to the literature.
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IPTA - New Gamma Correction Method for real time image text extraction
2019 Ninth International Conference on Image Processing Theory Tools and Applications (IPTA), 2019Co-Authors: Mohamed Amin Ben Atitallah, Rostom Kachouri, Ahmed Ben Atitallah, Hassene MnifAbstract:Text extraction and character recognition in manuscripts are a very important part of image processing and pattern recognition. The recently proposed Gamma Correction Method (GCM) is a popular method used in the processing of a color image and in particular in the extraction of text from a complex image. However, The GCM consumes a lot of time to extract the text and this is because of the complex calculations of different operations in the different blocks of GCM which is not suitable to real-time applications. In this paper, we propose an efficient Gamma Correction Method acceleration. Our proposal allows to minimize the GCM execution time while ensuring the same reliability of the initial version. The experimental results show an important optimization compared to the literature.
Gunhee Han - One of the best experts on this subject based on the ideXlab platform.
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cmos image sensor with analog Gamma Correction using nonlinear single slope adc
International Symposium on Circuits and Systems, 2006Co-Authors: Seogheon Ham, Yonghee Lee, Wunki Jung, Seunghyun Lim, Kwisung Yoo, Youngcheol Chae, Jihyun Cho, Dongmyung Lee, Gunhee HanAbstract:A human eye has the logarithmic response over wide range of light intensity. Although the gain can be set high to identify details in darker area on the image, this results in saturation in brighter area. The Gamma Correction is essential to fit the human eye. However, the digital Gamma Correction degrades image quality especially for darker area on the image due to the limited ADC resolution and the dynamic range. This paper proposes a CMOS image sensor (CIS) with nonlinear analog-to-digital converter (ADC) which performs analog Gamma Correction. The CIS with the proposed nonlinear ADC conversion scheme was fabricated with a 0.35-/spl mu/m CMOS process. The test results show the improved image quality than digital Gamma Correction.
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ISCAS - CMOS image sensor with analog Gamma Correction using nonlinear single-slope ADC
2006 IEEE International Symposium on Circuits and Systems, 2006Co-Authors: Seogheon Ham, Yonghee Lee, Wunki Jung, Seunghyun Lim, Kwisung Yoo, Youngcheol Chae, Jihyun Cho, Dongmyung Lee, Gunhee HanAbstract:A human eye has the logarithmic response over wide range of light intensity. Although the gain can be set high to identify details in darker area on the image, this results in saturation in brighter area. The Gamma Correction is essential to fit the human eye. However, the digital Gamma Correction degrades image quality especially for darker area on the image due to the limited ADC resolution and the dynamic range. This paper proposes a CMOS image sensor (CIS) with nonlinear analog-to-digital converter (ADC) which performs analog Gamma Correction. The CIS with the proposed nonlinear ADC conversion scheme was fabricated with a 0.35-/spl mu/m CMOS process. The test results show the improved image quality than digital Gamma Correction.
Seogheon Ham - One of the best experts on this subject based on the ideXlab platform.
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cmos image sensor with analog Gamma Correction using nonlinear single slope adc
International Symposium on Circuits and Systems, 2006Co-Authors: Seogheon Ham, Yonghee Lee, Wunki Jung, Seunghyun Lim, Kwisung Yoo, Youngcheol Chae, Jihyun Cho, Dongmyung Lee, Gunhee HanAbstract:A human eye has the logarithmic response over wide range of light intensity. Although the gain can be set high to identify details in darker area on the image, this results in saturation in brighter area. The Gamma Correction is essential to fit the human eye. However, the digital Gamma Correction degrades image quality especially for darker area on the image due to the limited ADC resolution and the dynamic range. This paper proposes a CMOS image sensor (CIS) with nonlinear analog-to-digital converter (ADC) which performs analog Gamma Correction. The CIS with the proposed nonlinear ADC conversion scheme was fabricated with a 0.35-/spl mu/m CMOS process. The test results show the improved image quality than digital Gamma Correction.
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ISCAS - CMOS image sensor with analog Gamma Correction using nonlinear single-slope ADC
2006 IEEE International Symposium on Circuits and Systems, 2006Co-Authors: Seogheon Ham, Yonghee Lee, Wunki Jung, Seunghyun Lim, Kwisung Yoo, Youngcheol Chae, Jihyun Cho, Dongmyung Lee, Gunhee HanAbstract:A human eye has the logarithmic response over wide range of light intensity. Although the gain can be set high to identify details in darker area on the image, this results in saturation in brighter area. The Gamma Correction is essential to fit the human eye. However, the digital Gamma Correction degrades image quality especially for darker area on the image due to the limited ADC resolution and the dynamic range. This paper proposes a CMOS image sensor (CIS) with nonlinear analog-to-digital converter (ADC) which performs analog Gamma Correction. The CIS with the proposed nonlinear ADC conversion scheme was fabricated with a 0.35-/spl mu/m CMOS process. The test results show the improved image quality than digital Gamma Correction.
Ahmed Ben Hamida - One of the best experts on this subject based on the ideXlab platform.
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ATSIP - A comparative study of MRI contrast enhancement techniques based on Traditional Gamma Correction and Adaptive Gamma Correction: Case of multiple sclerosis pathology
2018 4th International Conference on Advanced Technologies for Signal and Image Processing (ATSIP), 2018Co-Authors: Mouna Sahnoun, Fathi Kallel, Mariem Dammak, Chokri Mhiri, Kheireddine Ben Mahfoudh, Ahmed Ben HamidaAbstract:One of the most important preprocessing techniques is image Contrast Enhancement which is a technique that improve visual quality of an input image becoming more suitable for human analysis and perception. Numerous researches have been already developed for enhancement of Medical image for their important application, Traditional Gamma Correction is found to be one of the simplest technique for the contrast enhancement of medical image. This technique uses a set of varying parameter (y, c) which adjust effectively gray value intensity of the input image. Otherwise, Adaptive Gamma Correction technique have been appeared and have been proved its effectiveness by the use of adaptive (y, c) parameter which are determined adaptively from statistical information of input image. Traditional Gamma Correction (TGC) and Adaptive Gamma Correction (AGC) have been applied on three brain MRI modalities for patient with Multiple Sclerosis pathology. Qualitative and quantitative results are presented to illustrate the comparison of TGC and AGC to enhance the contrast of MRI images for better appearance of normal tissue and diseased tissue affected by MS pathology.
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a new adaptive Gamma Correction based algorithm using dwt svd for non contrast ct image enhancement
IEEE Transactions on Nanobioscience, 2017Co-Authors: Fathi Kallel, Ahmed Ben HamidaAbstract:The performances of medical image processing techniques, in particular CT scans, are usually affected by poor contrast quality introduced by some medical imaging devices. This suggests the use of contrast enhancement methods as a solution to adjust the intensity distribution of the dark image. In this paper, an advanced adaptive and simple algorithm for dark medical image enhancement is proposed. This approach is principally based on adaptive Gamma Correction using discrete wavelet transform with singular-value decomposition (DWT-SVD). In a first step, the technique decomposes the input medical image into four frequency sub-bands by using DWT and then estimates the singular-value matrix of the low–low (LL) sub-band image. In a second step, an enhanced LL component is generated using an adequate Correction factor and inverse singular value decomposition (SVD). In a third step, for an additional improvement of LL component, obtained LL sub-band image from SVD enhancement stage is classified into two main classes (low contrast and moderate contrast classes) based on their statistical information and therefore processed using an adaptive dynamic Gamma Correction function. In fact, an adaptive Gamma Correction factor is calculated for each image according to its class. Finally, the obtained LL sub-band image undergoes inverse DWT together with the unprocessed low–high (LH), high–low (HL), and high–high (HH) sub-bands for enhanced image generation. Different types of non-contrast CT medical images are considered for performance evaluation of the proposed contrast enhancement algorithm based on adaptive Gamma Correction using DWT-SVD (DWT-SVD-AGC). Results show that our proposed algorithm performs better than other state-of-the-art techniques.
