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find Keyword "quantitative" 43 results
  • The progress in imaging evaluation of liver iron concentration

    ObjectiveTo summarize the methods and research progress of imaging evaluation of liver iron concentration.MethodsThe current status and progress of different imaging techniques in liver iron overload research were reviewed by studying the relevant literatures at home and abroad. The methods for determining liver iron concentration and their advantages and disadvantages were summarized.ResultsThe imaging methods for determining liver iron concentration mainly included traditional non-enhanced CT and dual energy CT examination, magnetic resonance signal intensity ratio, relative signal intensity index, T2 and R2 values, magnetic resonance spectroscopy, T2* and R2* values, susceptibility weighted imaging, and quantitative susceptibility mapping.ConclusionLiver iron quantification imaging method, including dual-energy CT and magnetic resonance imaging could non-invasively and accurately assess the liver iron overload.

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  • A mechanical impedance-based measurement system for quantifying Parkinsonian rigidity

    At present the parkinsonian rigidity assessment depends on subjective judgment of neurologists according to their experience. This study presents a parkinsonian rigidity quantification system based on the electromechanical driving device and mechanical impedance measurement method. The quantification system applies the electromechanical driving device to perform the rigidity clinical assessment tasks (flexion-extension movements) in Parkinson’s disease (PD) patients, which captures their motion and biomechanical information synchronously. Qualified rigidity features were obtained through statistical analysis method such as least-squares parameter estimation. By comparing the judgments from both the parkinsonian rigidity quantification system and neurologists, correlation analysis was performed to find the optimal quantitative feature. Clinical experiments showed that the mechanical impedance has the best correlation (Pearson correlation coefficient r = 0.872, P < 0.001) with the clinical unified Parkinson’s disease rating scale (UPDRS) rigidity score. Results confirmed that this measurement system is capable of quantifying parkinsonian rigidity with advantages of simple operation and effective assessment. In addition, the mechanical impedance can be adopted to help doctors to diagnose and monitor parkinsonian rigidity objectively and accurately.

    Release date:2018-08-23 03:47 Export PDF Favorites Scan
  • A Quantitative Detection of Poincare Scatter for T-wave Alternans

    To study the quantitative detection method of T-wave alternans (TWA), we analyzed the relationship between the graphic mode of Poincare scatter and TWA, and proposed ‘horizontal search algorithm' to complete graphic processing. Then, based on the shape of Poincare scatter, we took Axial_ratio as the final index. Through Matlab simulation, Axial_ratio was compared with the results of spectral method (SM) and appropriate threshold value was selected to recognize the TWA. The results showed that Axial_ratio could accurately detect the TWA.

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  • Quantitative susceptibility mapping of ultra-high resolution monkey brain in vivo at 9.4 T

    Quantitative susceptibility mapping (QSM) can provide tissue susceptibility information and has been adapted for clinical research and diagnosis. QSM of monkey brain in vivo at 9.4 T has not been demonstrated so far. In this study 9.4 T in vivo monkey brain QSM was performed with 200 μm isotropic high-resolution. It was found that the inherent singularity problem for QSM diverged significantly at ultra-high image resolution during regularization process and resulted in severe image artifacts. The K-space division (TKD) was applied to eliminate the artifacts, with an optimal threshold level between 0.2 and 0.3. High resolution QSM of monkey brain in vivo can thus provide a novel tool for brain research.

    Release date:2019-06-17 04:41 Export PDF Favorites Scan
  • Expression and Significance of A Novel Gene BC047440 in Multiplicate Malignant Tumor Tissues

    【 Abstract 】 Objective To study the mRNA expression of BC047440 gene in multiplicate malignant tumor tissues and the corresponding adjacent tissues, and to investigate its roles in the carcinogenesis and development of malignant tumors. Methods Forty-eight cases of malignant tumor tissues and their adjacent non-cancerous tissues were examined. The mRNA expression of BC047440 gene in those tissues of liver cancer, cholangiocarcinoma, gastric cancer, carcinoma of large intestine, glioma, and breast cancer were measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Results ① The mRNA expressions of BC047440 gene in liver cancer, gastric cancer, cholangiocarcinoma and carcinoma of large intestine were significantly higher than those in their adjacent non-cancerous tissues (Plt;0.05 or 0.01). BC047440 gene were highly expressed in both glioma and its adjacent tissues (Pgt;0.05), and poorly expressed in both breast cancer and its adjacent tissues (Pgt;0.05). ② There were close relationships between BC047440 gene expression and clinicopathologic findings of liver cancer, including tumor size and portal vein invasion (Plt;0.05). ③ There were also close relationships between BC047440 gene expression and different clinical stages in alimentary canal cancers (Plt;0.05). Conclusion The over expression of BC047440 gene may be related with the growth, infiltration and metastasis of some malignant tumors, including liver cancer, cholangiocarcinoma, gastric cancer, carcinoma of large intestine and glioma.

    Release date:2016-09-08 11:43 Export PDF Favorites Scan
  • The research progress of magnetic resonance quantitative technique in the iron overload of the abdominal parenchyma organ

    Objective To summarize the research progress of magnetic resonance quantitative technique in the iron overload of the abdominal parenchyma organ. Methods By reviewing the related literatures domesticly and abroad, the present status and progress of abdominal magnetic resonance quantitative technique and other examinations in the study of iron overload were analyzed. Results MRI multi-sequence examination technique had changed the research model of iron overload in different organs, and had important clinical significance in imaging diagnosis of abdominal parenchyma organ damage. so far, many techniques of MRI had been used in detection of iron overload, which included signal intensity measurements(including signal intensity ratio and signal intensity difference of positive and negative phases), T2/R2 measurements, T2*/R2* measurements, Dixon and its derivatization, ultrashort echo time technique and susceptibility weighted imaging (including conventional susceptibility weighted imaging and quantitative magnetic sensitive imaging). Conclusion Magnetic resonance quantitative examination technique is expected to be the first choice for detection of hepatic iron overload, and can improve the early detection rate of iron overload pancreatic damage.

    Release date:2017-09-18 04:11 Export PDF Favorites Scan
  • Totally arterialized minimally invasive coronary artery bypass grafting under the guidance of coronary artery function: A case report

    We reported a 59-year-old male with exertional angina pectoris, and the coronary angiography showed multiple vessel lesions. The initial strategy was coronary artery bypass grafting (CABG). The measurement of quantitative flow ration (QFR) before operation indicated that the posterior descending branch (PD) did not need to be treated. The left circumflex branch (LCX) was small, and the QFR of the left anterior descending branch (LAD) and the first diagonal branch (D1) was<0.8. Therefore, the LAD and D1 were re-vascularized. The operation strategy was changed to on-pump CABG through a small incision, and the final strategy was LIMA-D1-LAD (sequential), fractional flow reserve (FFR) of distal LAD and D1 after CABG were>0.8 by computed tomography FFR. SYNTAX scores after CABG were 20 and the functional SYNTAX scores after CABG were 3, indicating a good prognosis.

    Release date:2024-04-28 03:40 Export PDF Favorites Scan
  • Design and implementation of ultrasound molecular imaging quantitative analysis software based on region of interest

    Quantitative analysis of ultrasound molecular imaging is of great significance for clinical diagnosis and research. Based on Visual Studio development platform and C# language, this paper designs a set of ultrasound molecular imaging region of interest quantitative analysis software, which can complete the ultrasound image scaling processing, rectangular and arbitrary shape of the region of interest capture, mark saving and loading, gray value quantitative analysis and so on. In this paper, the function of the software is described in detail and the software is tested and verified. It is proved that the software can quantitatively analyze the conventional ultrasound images and ultrasound contrast images, which can provide a basis for the relevant research on the quantitative analysis of the gray value of ultrasound molecular imaging.

    Release date:2022-12-23 09:29 Export PDF Favorites Scan
  • Detection of plasmatic trace amounts of microRNAs with two kinds of small RNA real-time polymerase chain reaction methods

    Objective To detect traces of microRNAs (miRNAs) in plasma and assess the expression stability of two common reference genes by stem-loop and poly A polymerase (PAP) real-time quantitative polymerase chain reaction (PCR) method, as miRNAs are the new bio-markers of tumor diagnosis and molecular targeted therapy, and its quantitative research is very important. Methods We extracted miRNAs from plasma of adult Sprague Dawley (SD) rats’ plasma, and detected the expressions of rno-miR-200b-3p and rno-miR-126-3p with stem-loop and PAP real-time PCR quantitative method, with rno-miR-103a-3p and U6 as internal controls. All the results were evaluated by 2△Ct method. Results Compared with PAP method, the stem-loop method reduced Ct value by 2-4 cycles and improved sensitivity by 10 times. In PAP method, the melting curve showed two peaks, a main peak and a small non-specific peak. Yet the melting curve of stem-loop method demonstrated a single specific peak. Furthermore, we validated the stability of internal references in the two real time PCR methods. U6 presented a more stable Ct value than rno-miR-103 in adult SD rats’ plasma samples. Conclusions Stem-loop real-time PCR is recommended as a major way to detect some samples with a low concentration of miRNAs, owing to its high accuracy and sensitivity. However, if a large number of tissue samples is going to be detected, PAP real-time PCR is more suitable and convenient than stem-loop method. U6 is more stable and repeatable than rno-miR-103a-3p as the reference gene to evaluate the semi-quantitative consequence of miRNAs.

    Release date:2017-05-18 01:09 Export PDF Favorites Scan
  • HISTOLOGICAL STUDIES AND MORPHOMETRIC QUANTITATIVE ANALYSIS ON TRIAL RABBIT’S COMMON BILE DUCT IN ITS DILATANT PROCESS

    Histological studies and morphometry quantitative analysis have been performed on trial rabbit’s dilated common bile duct(CBD),which does not dilate simultaneously.The results shows:①Epithelia of rabbit’s CBD have a ber reparable function,which is fairly significant to the prevention of bile duct’s further injure under the pathogenic situation.②The smooth muscle cell(SMC)of the CBD is the histological basis of contraction,some SMC can be seen in contracting state under light microscope.This indicates that the SMC in rabbit’s CBD possess contracting function.③The collagenous and elastic fibers have the normal histological morphometric characteristics and quantity in it’s dilatation process,and no breekdown and degeneration of the fibers can be detected.Because of the morphological structure of these sections is quite similiar with normal ones,theoretically,we suspect that when pathological change of bile duct’s distal portion is relieved and the bile pressure is normal again.It is possible for this dilating bile duct to return to its formal shape and size.

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