scholarly journals Dependence of Intravoxel Incoherent Motion diffusion MR threshold b-value selection for separating perfusion and diffusion compartments and liver fibrosis diagnostic performance

2017 ◽  
Author(s):  
Yao Li ◽  
Pu-Xuan Lu ◽  
Hua Huang ◽  
Jason Leung ◽  
Weitian Chen ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Dimensional Space ◽  
B Value ◽  
Intravoxel Incoherent Motion ◽  
Fibrotic Liver ◽  
3 Dimensional ◽  
Diffusion Parameters ◽  
Respiration Gating ◽  
And Diffusion ◽  
Selection Of

AbstractPurposeTo explore how the selection of threshold b-value impacts Intravoxel Incoherent Motion (IVIM) diffusion parameters of PF (f), Dslow (D),and Dfast (D*) values and their performance for liver fibrosis detection.Materials and MethodsFifteen healthy volunteers and 33 hepatitis-b patients were included. With a 1.5 T MR scanner and respiration gating, IVIM data was acquired with 10 b-values of 10,20,40,60,80,100,150, 200, 400, and 800 s/mm2. Signal measurement was performed on right liver. Segmented-unconstrained analysis was used to compute IVIM parameters, and six threshold b-values between 40 and 200 s/mm2 were compared. PF, Dslow, and Dfast values were placed along the x-axis, y-axis, and z-axis, and a plane was defined to separate volunteers from patients.ResultsHigher threshold b-values were associated with higher PF measurement; while lower threshold b-values led to higher Dslow and Dfast measurements. The dependence of PF, Dslow, and Dfast on threshold b-value differed between healthy livers and fibrotic livers; with the healthy livers showing a higher dependence. Threshold b-value=60 s/mm2 showed the largest mean distance between healthy liver datapoints vs. fibrotic liver datapoints in 3-dimensional space.ConclusionFor segmented-unconstrained analysis, the selection of threshold b-value=60 s/mm2 improves IVIM diffusion differentiation between healthy livers and fibrotic livers.

scholarly journals Dependence of intravoxel incoherent motion diffusion MR threshold b-value selection for separating perfusion and diffusion compartments and liver fibrosis diagnostic performance

2018 ◽  
Vol 60 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Yì Xiáng J Wáng ◽  
Yáo T Li ◽  
Olivier Chevallier ◽  
Hua Huang ◽  
Jason Chi Shun Leung ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Area Under The Curve ◽  
Regression Tree ◽  
B Value ◽  
Classification And Regression Tree ◽  
Intravoxel Incoherent Motion ◽  
Fibrotic Liver ◽  
B Values ◽  
D Values ◽  
The Right

Background Intravoxel incoherent motion (IVIM) tissue parameters depend on the threshold b-value. Purpose To explore how threshold b-value impacts PF ( f), Dslow ( D), and Dfast ( D*) values and their performance for liver fibrosis detection. Material and Methods Fifteen healthy volunteers and 33 hepatitis B patients were included. With a 1.5-T magnetic resonance (MR) scanner and respiration gating, IVIM data were acquired with ten b-values of 10, 20, 40, 60, 80, 100, 150, 200, 400, and 800 s/mm2. Signal measurement was performed on the right liver. Segmented-unconstrained analysis was used to compute IVIM parameters and six threshold b-values in the range of 40–200 s/mm2 were compared. PF, Dslow, and Dfast values were placed along the x-axis, y-axis, and z-axis, and a plane was defined to separate volunteers from patients. Results Higher threshold b-values were associated with higher PF measurement; while lower threshold b-values led to higher Dslow and Dfast measurements. The dependence of PF, Dslow, and Dfast on threshold b-value differed between healthy livers and fibrotic livers; with the healthy livers showing a higher dependence. Threshold b-value = 60 s/mm2 showed the largest mean distance between healthy liver datapoints vs. fibrotic liver datapoints, and a classification and regression tree showed that a combination of PF (PF < 9.5%), Dslow (Dslow < 1.239 × 10–3 mm2/s), and Dfast (Dfast < 20.85 × 10–3 mm2/s) differentiated healthy individuals and all individual fibrotic livers with an area under the curve of logistic regression (AUC) of 1. Conclusion For segmented-unconstrained analysis, the selection of threshold b-value = 60 s/mm2 improves IVIM differentiation between healthy livers and fibrotic livers.

Association algorithm with bearing-only measurements in 3-dimensional space

2009 ◽  
Author(s):  
Xiu Jianjuan ◽  
Li Yuli ◽  
He You ◽  
Wang Guohong
Keyword(s):  
Dimensional Space ◽  
3 Dimensional ◽  
Association Algorithm

Triharmonic Riemannian submersions from 3-dimensional space forms

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tomoya Miura ◽  
Shun Maeta
Keyword(s):  
Existence Theorem ◽  
Space Form ◽  
Dimensional Space ◽  
Riemannian Submersion ◽  
Partial Answer ◽  
Riemannian Submersions ◽  
Space Forms ◽  
3 Dimensional

Abstract We show that any triharmonic Riemannian submersion from a 3-dimensional space form into a surface is harmonic. This is an affirmative partial answer to the submersion version of the generalized Chen conjecture. Moreover, a non-existence theorem for f -biharmonic Riemannian submersions is also presented.

Possible Therapeutic Uses of Extracellular Vesicles for Reversion of Activated Hepatic Stellate Cells: Context and Future Perspectives

2021 ◽  
Vol 21 ◽  
Author(s):  
Fahim Rejanur Tasin ◽  
Debasish Halder ◽  
Chanchal Mandal
Keyword(s):  
Liver Fibrosis ◽  
Extracellular Vesicles ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Target Cells ◽  
Fibrotic Liver ◽  
Paracrine Effects ◽  
Cell Therapies

: Liver fibrosis is one of the leading causes for cirrhotic liver disease and the lack of therapies to treat fibrotic liver is a major concern. Liver fibrosis is mainly occurred by activation of hepatic stellate cells and some stem cell therapies had previously reported for treatment. However, due to some problems with cell-based treatment, a safe therapeutic agent is vehemently sought by the researchers. Extracellular vesicles are cell-derived nanoparticles that are employed in several therapeutic approaches, including fibrosis, for their ability to transfer specific molecules in the target cells. In this review the possibilities of extracellular vesicles to inactivate stellate cells are summarized and discussed. According to several studies, extracellular vesicles from different sources can either put beneficial or detrimental effects by regulating the activation of stellate cells. Therefore, targeting extracellular vesicles for maximizing or inhibiting their production is a potential approach for fibrotic liver treatment. Extracellular vesicles from different cells can also inactivate stellate cells by carrying out the paracrine effects of those cells, working as the agents. They are also implicated as smart carrier of anti-fibrotic molecules when their respective parent cells are engineered to produce specific stellate cell-regulating substances. A number of studies showed stellate cell activation can be regulated by up/downregulation of specific proteins, and extracellular vesicle-based therapies can be an effective move to exploit these mechanisms. In conclusion, EVs are advantageous nano-carriers with the potential to treat fibrotic liver by inactivating activated stellate cells by various mechanisms.

Sign in / Sign up

Export Citation Format

Share Document