• Title/Summary/Keyword: Quantitative CT

Search Result 325, Processing Time 0.021 seconds

Surface Rendering in Abdominal Aortic Aneurysm by Deformable Model (복부대동맥의 3차원 표면모델링을 위한 가변형 능동모델의 적용)

  • Choi, Seok-Yoon;Kim, Chang-Soo
    • The Journal of the Korea Contents Association
    • /
    • v.9 no.6
    • /
    • pp.266-274
    • /
    • 2009
  • An abdominal aortic aneurysm occurs most commonly in older individuals (between 65 and 75), and more in men and smokers. The most important complication of an abdominal aortic aneurysm is rupture, which is most often a fatal event. An abdominal aortic aneurysm weakens the walls of the blood vessel, leaving it vulnerable to bursting open, or rupturing, and spilling large amounts of blood into the abdominal cavity. surface modeling is very useful to surgery for quantitative analysis of abdominal aortic aneurysm. the 3D representation and surface modeling an abdominal aortic aneurysm structure taken from Multi Detector Computed Tomography. The construction of the 3D model is generally carried out by staking the contours obtained from 2D segmentation of each CT slice, so the quality of the 3D model strongly defends on the precision of segmentation process. In this work we present deformable model algorithm. deformable model is an energy-minimizing spline guided by external constraint force. External force which we call Gradient Vector Flow, is computed as a diffusion of a gradient vectors of gray level or binary edge map derived from the image. Finally, we have used snakes successfully for abdominal aortic aneurysm segmentation the performance of snake was visually and quantitatively validated by experts.

Quantitative Assessment of Salivary Gland washout in Clinically Healthy Dogs

  • Jang, Won-seok;Hwang, Tae-sung;Jung, Dong-in;Lee, Jae-hoon;Lee, Hee-chun
    • Journal of Veterinary Clinics
    • /
    • v.37 no.1
    • /
    • pp.28-33
    • /
    • 2020
  • The aims of this study were to obtain the normal ranges of enhancement parameters for salivary gland in dynamic CT and to investigate the effects of fasting time on contrast enhancement in clinically normal beagle dogs. With five healthy beagle dogs, dynamic CT examination was performed according to fasting times (as fasting times, 12hours, 0 min, 20 min, 40 min, 1 hours, 6 hours, 24 hours). In normal beagles with 12hours fasting, enhancement parameters through the preliminary study were as follows: ImaxA - 472 .49 ± 19.01 HU; ImaxS - 138.95 ± 6.2 5 HU; TmaxA - 25.8 ± 1.79 sec; TmaxS - 69.0 ± 23.11 sec; Teq - 80.5 ± 6.61 sec; T-Aeq - 54.5 ± 5.51 sec (Imax - peak enhancement; Tmax - time to peak enhancement; Teq - time to equilibrium phase; T-Aeq - time between peak enhancement in the common carotid artery and onset of the equilibrium phase; A - common carotid; S - submandibular gland; HU - Hounsfield unit). Additionally, ImaxA and ImaxS were significantly increased in 40 min after eating. Because these results associated with postprandial hemodynamic changes can make the diagnosis of salivary gland diseases more difficult, sufficient fasting time is important for accurate diagnosis.

Identification of Endogenous Genes for Normalizing Titer Variation of Citrus Tristeza Virus in Aphids at Different Post-acquisition Feeding Times

  • Wang, Hongsu;Chen, Qi;Liu, Luqin;Zhou, Yan;Wang, Huanhuan;Li, Zhongan;Liu, Jinxiang
    • The Plant Pathology Journal
    • /
    • v.38 no.4
    • /
    • pp.287-295
    • /
    • 2022
  • Citrus tristeza virus (CTV) is efficiently transmitted in a semi-persistent manner by the brown citrus aphid (Toxoptera citricida (Kirkaldy)). Currently, the most sensitive method for detecting plant viruses in insect vectors is reverse-transcription quantitative polymerase chain reaction (RT-qPCR). In this study, the elongation factor-1 alpha (EF-1α) gene and acidic p0 ribosomal protein (RPAP0) gene were confirmed to be suitable reference genes for RT-qPCR normalization in viruliferous T. citricida aphids using the geNorm, NormFinder, and BestKeeper tools. Then the relative CTV titer in aphids (T. citricida) at different post-acquisition feeding times on healthy plants was quantified by RT-qPCR using EF-1α and RPAP0 as reference genes. The relative CTV titer retained in the aphids gradually decreased with increasing feeding time. During the first 0.5 h of feeding time on healthy plants, the remaining CTV titer in aphids showed about 80% rapid loss for the highly transmissible isolate CT11A and 40% loss for the poorly transmissible isolate CTLJ. The relative CTV titer in aphids during more than 12 h post-acquisition times for CT11A was significantly lower than at the other feeding times, which is similar to the trend found for CTLJ. To our knowledge, this is the first report about the relative titer variation of CTV remaining in T. citricida at different post-acquisition feeding times on healthy plants.

Evaluation of Clinical Availability for Shoulder Forced Traction Method to Minimize the Beam Hardening Artifact in Cervical-spine Computed Tomography (CT) (경추부 전산화단층촬영에서 선속 경화 인공물을 최소화하기 위한 견부 강제 견인법에 대한 임상적 유용성 평가)

  • Kim, Moonjeung;Cho, Wonjin;Kang, Suyeon;Lee, Wonseok;Park, Jinwoo;Yu, Yunsik;Im, Inchul;Lee, Jaeseung;Kim, Hyeonjin;Kwak, Byungjoon
    • Journal of the Korean Society of Radiology
    • /
    • v.7 no.1
    • /
    • pp.37-44
    • /
    • 2013
  • In study suggested clinical availability to shoulder forced traction method in term of quality of image, the patient's convenience and stability, according to whether to use of shoulder forced traction bend using computed tomography(CT) that X-ray calibration and various mathematic calibration algorithm application can be applied by AEC. To achieve this, 79 patients is complaining of cervical pain oriented that shoulder forced traction bend use the before and after acquires lateral projection scout image and transverse image. transverse image of a fixed size in concern field of pixel and figure the average HU value compare that quantitative analysis. Artifact and pixel and resolution to qualitative clinical estimation image analysis. the patient feel inconvenience degree that self-diagnosis survey that estimate. As a result, lateral projection scout image if you used shoulder forced traction bend for the depicted has been an increase in the number of a cervical vertebrae. transverse image concern field shoulder forced traction bend use the before and after for pixel and the average HU-value changes was judged to be almost irrelevant. Artifact and resolution and contrast, in qualitative analysis of the results relating the observer to the unusual result. So, the patients of 82.27% complained discomfort that use of shoulder forced traction bend in self-diagnosis survey. No merit of medical image by using of bend from result was analyzed quality of image to quantitative and qualitative method judged. Nowadays, CT is supplied possible revision of quality of radiation by reduction of slice and automatic exposure controller, etc and application of preconditioning filter process due to various mathematic revision algorithm. So, image noise by beam hardening artifact should not be a problem. shoulder forced traction bend of use no longer judged clinically availability because have not influence of image quality and give discomfort, have extra dangerousness.

A Study on the Optimal Image Acquisition Time of 18F- Flutemetamol using List Mode (LIST mode를 이용한 18F-Flutemetamol 의 최적 영상획득 시간에 관한 연구)

  • Ryu, Chan-Ju
    • Journal of the Korean Society of Radiology
    • /
    • v.15 no.6
    • /
    • pp.891-897
    • /
    • 2021
  • With the development of Amyloid PET Tracer, the accuracy of Alzheimer's diagnosis can be improved through the identification of beta-amyloid neurites. However, the long image acquisition time of 20 minutes can be difficult for the patient. PET/CT scans are sensitive to patient movement and may partially affect test results. In this study, we studied the proper image acquisition time without affecting the quantitative evaluation of the image through the list mode acquisition method according to the time of the distribution of radioactive drugs in the body. The list mode includes information about time compared to the existing frame mode, and it is easy to analyze data because it can reconstruct images about the time that researchers want. The research method obtained a reconstructed image by time using a list mode of 5min frame/bed, 10min frame/bed, 15min frame/bed, and 20min frame/bed to compare the difference between signal-to-pons take ratio (SNR) and lesion-to-pons uptake ratio (LPR) and the difference in reading time to obtain an appropriate image. As a result of quantitative analysis, when measuring in list mode, SUVmean values decreased in 6 regions of interest as the image acquisition time increased, but showed the largest difference in 5 min/bed images, followed by 10 min/bed and 15 min/bed. As a result, the difference in SUVmean values decreased. Therefore, it was found that SUVmean values at 15 min/bed did not differ enough to not affect image evaluation. There was no difference in LPR values. As a result of the qualitative analysis, there was no change in the reading findings according to the PET image acquisition time and there was no significant difference in the qualitative analysis score of the image reconstruction according to time. As a result of the study, there is no significant difference between 15 min/bed and 20 min/bed images during the 18F-flutemetamol PET/CT test, so it can be said that it is clinically useful to reduce the image acquisition time selectively using 15 min/bed via list mode depending on the patient's condition.

Evaluation of Usefulness of an m-DIXON Technique during an Abdomen MRI Examination : A Comparison with an e-THRIVE Technique (복부 MRI검사에서 m-DIXON기법의 유용성 평가: e-THRIVE기법과 비교 분석)

  • Lee, Bo-Woo;Park, Myung-Cheol;Lee, Jin-Hoi;Kim, Ki-Jin;Bae, Seok-Hwan
    • Journal of Digital Convergence
    • /
    • v.12 no.10
    • /
    • pp.385-390
    • /
    • 2014
  • This research is conducted to identify whether an m-DIXON technique which is useful for an abdomen MRI examination compared with an existing e-THRIVE technique is a clinically useful or not. There was evaluated quantitative and qualitative to 84 subjects who had abdomen MRI exam due to their liver disease were conducted during a period from September in 2013 to February in 2014. First of all the quantitative evaluation, the m-DIXON technique's SNR was $90.42{\pm}16.90$ and the e-THRIVE technique was $60.42{\pm}11.54$ and the m-DIXON technique's CNR was $52.38{\pm}22.58$ and the e-THRIVE technique was $46.31{\pm}20.25$. Secondly in the qualitative evaluation, the m-DIXON technique's image quality was $4.06{\pm}0.34$, a artifact was $3.64{\pm}0.22$, and fat suppression was $4.16{\pm}0.15$, the e-THRIVE technique's image quality was $3.14{\pm}0.35$, a artifact was $3.06{\pm}0.38$, fat suppression was $3.14{\pm}0.30$. In conclusion, m-DIXON technique for abdomen MRI examination showed superiority over both SNR as a quantitative anaylsis, CNR and a qualitative analysis.

Gene Expression of Heart and Adipocyte Fatty Acid-binding Protein in Chickens by FQ-RT-PCR

  • Tu, Yunjie;Su, Yijun;Wang, Kehua;Zhang, Xueyu;Tong, Haibing;Gao, Yushi
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.23 no.8
    • /
    • pp.987-992
    • /
    • 2010
  • This study was to detect the expression of heart fatty acid-binding protein (H-FABP) and adipocyte fatty acid-binding protein (A-FABP) gene mRNA in different tissues of Rugao and Luyuan chickens at 56 d and 120 d by real-time fluorescence quantitative reverse transcription polymerase-chain reaction (FQ-RT-PCR). The primers were designed according to the sequences of HFABP, A-FABP and GAPDH genes in Gallus gallus, which were used as target genes and internal reference gene, respectively. The levels of H-FABP and A-FABP gene expression were detected by SYBR Green I FQ-RT-PCR. The relative H-FABP and A-FABP gene mRNA expression level was calculated with 2-$^{{\Delta}Ct}$. Melting curve analysis showed a single peak of three genes. Intramuscular fat (IMF) content in breast muscle and leg muscle of the two chicken breeds at 120 d was higher than at 56 d. IMF content in breast muscle and leg muscle at 56 d and 120 d in Luyuan was significantly higher than in Rugao, however, abdominal fat of Luyuan was significantly lower than that of Rugao. The relative H-FABP gene mRNA expression level in cardiac muscle was the highest in both chicken breeds. The relative H-FABP and A-FABP gene expression of different tissues in Luyuan was higher than in Rugao. H-FABP gene mRNA expression had a negative effect on IMF of leg and breast muscles, and was significantly negatively correlated with IMF content. The relative A-FABP gene mRNA level in abdominal fat was higher than in liver. The A-FABP gene mRNA was not expressed in leg, breast and cardiac muscles. A-FABP gene mRNA expression level was significantly positively correlated with abdominal fat and had a significant effect on abdominal fat but not IMF content.

Evaluation of reference genes for RT-qPCR study in abalone Haliotis discus hannai during heavy metal overload stress

  • Lee, Sang Yoon;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
    • /
    • v.19 no.4
    • /
    • pp.21.1-21.11
    • /
    • 2016
  • Background: The evaluation of suitable reference genes as normalization controls is a prerequisite requirement for launching quantitative reverse transcription-PCR (RT-qPCR)-based expression study. In order to select the stable reference genes in abalone Haliotis discus hannai tissues (gill and hepatopancreas) under heavy metal exposure conditions (Cu, Zn, and Cd), 12 potential candidate housekeeping genes were subjected to expression stability based on the comprehensive ranking while integrating four different statistical algorithms (geNorm, NormFinder, BestKeeper, and ${\Delta}CT$ method). Results: Expression stability in the gill subset was determined as RPL7 > RPL8 > ACTB > RPL3 > PPIB > RPL7A > EF1A > RPL4 > GAPDH > RPL5 > UBE2 > B-TU. On the other hand, the ranking in the subset for hepatopancreas was RPL7 > RPL3 > RPL8 > ACTB > RPL4 > EF1A > RPL5 > RPL7A > B-TU > UBE2 > PPIB > GAPDH. The pairwise variation assessed by the geNorm program indicates that two reference genes could be sufficient for accurate normalization in both gill and hepatopancreas subsets. Overall, both gill and hepatopancreas subsets recommended ribosomal protein genes (particularly RPL7) as stable references, whereas traditional housekeepers such as ${\beta}-tubulin$ (B-TU) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were ranked as unstable genes. The validation of reference gene selection was confirmed with the quantitative assay of MT transcripts. Conclusions: The present analysis showed the importance of validating reference genes with multiple algorithmic approaches to select genes that are truly stable. Our results indicate that expression stability of a given reference gene could not always have consensus across tissue types. The data from this study could be a good guide for the future design of RT-qPCR studies with respect to metal regulation/detoxification and other related physiologies in this abalone species.

Validation of housekeeping genes as candidate internal references for quantitative expression studies in healthy and nervous necrosis virus-infected seven-band grouper (Hyporthodus septemfasciatus)

  • Krishnan, Rahul;Qadiri, Syed Shariq Nazir;Kim, Jong-Oh;Kim, Jae-Ok;Oh, Myung-Joo
    • Fisheries and Aquatic Sciences
    • /
    • v.22 no.12
    • /
    • pp.28.1-28.8
    • /
    • 2019
  • Background: In the present study, we evaluated four commonly used housekeeping genes, viz., actin-β, elongation factor-1α (EF1α), acidic ribosomal protein (ARP), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as internal references for quantitative analysis of immune genes in nervous necrosis virus (NNV)-infected seven-band grouper, Hyporthodus septemfasciatus. Methods: Expression profiles of the four genes were estimated in 12 tissues of healthy and infected seven-band grouper. Expression stability of the genes was calculated using the delta Ct method, BestKeeper, NormFinder, and geNorm algorithms. Consensus ranking was performed using RefFinder, and statistical analysis was done using GraphpadPrism 5.0. Results: Tissue-specific variations were observed in the four tested housekeeping genes of healthy and NNV-infected seven-band grouper. Fold change calculation for interferon-1 and Mx expression using the four housekeeping genes as internal references presented varied profiles for each tissue. EF1α and actin-β was the most stable expressed gene in tissues of healthy and NNV-infected seven-band grouper, respectively. Consensus ranking using RefFinder suggested EF1α as the least variable and highly stable gene in the healthy and infected animals. Conclusions: These results suggest that EF1α can be a fairly better internal reference in comparison to other tested genes in this study during the NNV infection process. This forms the pilot study on the validation of reference genes in Hyporthodus septemfasciatus, in the context of NNV infection.

Norovirus Quantification in Oysters Crassostrea gigas Collected from Tongyeoung, Korea (통영시 연안의 양식굴(Crassostrea gigas)에서 검출된 노로바이러스의 정량분석)

  • Shin, Soon Bum;Oh, Eun-Gyoung;Lee, Hee-Jung;Kim, Yeon Kye;Lee, Tae Seek;Kim, Ji-Hoe
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.47 no.5
    • /
    • pp.501-507
    • /
    • 2014
  • Norovirus (NoV) is a major cause of food poisoning outbreaks in Korea. Most NoV outbreaks originate from environmental contamination, but bivalves such as oysters are also important vectors. Oyster Crassostrea gigas contamination by NoV has been reported in Korea, but no quantitative analyses of NoV have been performed. We investigated the NoV concentration in 21 oyster samples from a Korean commercial oyster-growing area with confirmed fecal contamination from January to December 2012, using real-time reverse transcription-polymerase chain reaction. Additionally, we assessed the NoV concentration after heating to investigate the effects of heat treatment on NoV-infected oysters. In NoV-positive samples, the cycle threshold (Ct) values were 37.43-39.41 and 36.77-39.30, while viral concentrations were $8.97{\times}10^2-2.24{\times}10^2$ and $3.05{\times}10^2-7.47{\times}10^1$ copies/g for genogroups I and II, respectively. After heat treatment, NoV genogroup I decreased by 83.4%, 88.0%, 89.4% and 100% at $60^{\circ}C$, $68^{\circ}C$, $70^{\circ}C$, and $100^{\circ}C$, respectively, for 15 min, while genogroup II respectively decreased by 67.3%, 76.3%, 80.1%, and 89.8% under the same conditions.