scholarly journals Synthetic extracellular volume fraction without hematocrit sampling for hepatic applications

2021 ◽  
Author(s):  
Narine Mesropyan ◽  
Patrick Kupczyk ◽  
Alexander Isaak ◽  
Christoph Endler ◽  
Anton Faron ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Pearson Correlation ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Radiology Department ◽  
Clinical Implementation ◽  
Derivation Cohort ◽  
Non Invasive ◽  
Potential Biomarker ◽  
Before And After

Abstract Purpose Calculation of extracellular volume fraction (ECV) currently receives increasing interest as a potential biomarker for non-invasive assessment of liver fibrosis. ECV calculation requires hematocrit (Hct) sampling, which might be difficult to obtain in a high-throughput radiology department. The aim of this study was to generate synthetic ECV for hepatic applications without the need for Hct sampling. Methods In this prospective study participants underwent liver MRI. T1 mapping was performed before and after contrast administration. Blood Hct was obtained prior to MRI. We hypothesized that the relationship between Hct and longitudinal relaxation rate of blood (R1 = 1/T1blood) could be calibrated and used to generate the equation for synthetic Htc and ECV calculation. Conventional and synthetic ECV were calculated. Pearson correlation, linear regression and Bland–Altman method were used for statistical analysis. Results 180 consecutive patients were divided into derivation (n = 90) and validation (n = 90) cohorts. In the derivation cohort, native R1blood and Hct showed a linear relationship (HctMOLLI = 98.04 × (1/T1blood) − 33.17, R2 = 0.75, P < 0.001), which was used to calculate synthetic ECV in the validation and whole study cohorts. Synthetic and conventional ECV showed significant correlations in the derivation, validation and in the whole study cohorts (r = 0.99, 0.97 and 0.99, respectively, P < 0.001, respectively) with minimal bias according to the Bland–Altman analysis. Conclusion Synthetic ECV seems to offer an alternative method for non-invasive quantification of the hepatic ECV. It may potentially overcome an important barrier to clinical implementation of ECV and thus, enable broader use of hepatic ECV in routine clinical practice.

SAT-423-Spleen extracellular volume fraction and platelet count/spleen volume ratio are accurate non-invasive markers of portal hypertension

2019 ◽  
Vol 70 (1) ◽  
pp. e820-e821
Author(s):  
Christina Levick ◽  
Michael Pavlides ◽  
DavidJ Breen ◽  
Kathryn Nash ◽  
Gideon Hirschfield ◽  
...  
Keyword(s):  
Platelet Count ◽  
Portal Hypertension ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Volume Ratio ◽  
Extracellular Volume Fraction ◽  
Spleen Volume ◽  
Non Invasive

scholarly journals Non-invasive assessment of liver fibrosis in autoimmune hepatitis: Diagnostic value of liver magnetic resonance parametric mapping including extracellular volume fraction

2020 ◽  
Author(s):  
Narine Mesropyan ◽  
Patrick Kupczyk ◽  
Leona Dold ◽  
Tobias J. Weismüller ◽  
Alois M. Sprinkart ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Liver Stiffness ◽  
Extracellular Volume Fraction ◽  
Diagnostic Value ◽  
Parametric Mapping ◽  
Significant Fibrosis ◽  
Non Invasive ◽  
Mapping Parameters

Abstract Purpose Autoimmune hepatitis (AIH) is an immune-mediated chronic liver disease that leads to severe fibrosis and cirrhosis. The aim of this study was to determine the diagnostic value of T1 and T2 mapping as well as extracellular volume fraction (ECV) for non-invasive assessment of liver fibrosis in AIH patients. Methods In this prospective study, 27 patients (age range: 19–77 years) with AIH underwent liver MRI. T1 and T2 relaxation times as well as ECV were quantified by mapping techniques. The presence of significant fibrosis (≥ F2) was defined as magnetic resonance elastography (MRE)-based liver stiffness ≥ 3.66 kPa. MRE was used as reference standard, against which the diagnostic performance of MRI-derived mapping parameters was tested. Diagnostic performance was compared by utilizing receiver-operating characteristic (ROC) analysis. Results MRE-based liver stiffness correlated with both, hepatic native T1 (r = 0.69; P < 0.001) as well as ECV (r = 0.80; P < 0.001). For the assessment of significant fibrosis, ECV yielded a sensitivity of 85.7% (95% confidence interval (CI): 60.1–96.0%) and a specificity of 84.6% (CI 60.1–96.0%); hepatic native T1 yielded a sensitivity of 85.7% (CI 60.1–96.0%); and a specificity of 76.9% (CI 49.7–91.8%). Diagnostic performance of hepatic ECV (area under the curve (AUC): 0.885), native hepatic T1 (AUC: 0.846) for assessment of significant fibrosis was similar compared to clinical fibrosis scores (APRI (AUC: 0.852), FIB-4 (AUC: 0.758), and AAR (0.654) (P > 0.05 for each comparison)). Conclusion Quantitative mapping parameters such as T1 and ECV can identify significant fibrosis in AIH patients. Future studies are needed to explore the value of parametric mapping for the evaluation of different disease stages.

Quantitative liver MRI including extracellular volume fraction for non-invasive quantification of liver fibrosis: a prospective proof-of-concept study

Gut ◽  
2017 ◽  
Vol 67 (3) ◽  
pp. 593-594 ◽  
Author(s):  
Julian A Luetkens ◽  
Sabine Klein ◽  
Frank Traeber ◽  
Frederic C Schmeel ◽  
Alois M Sprinkart ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Proof Of Concept ◽  
Liver Mri ◽  
Concept Study ◽  
Non Invasive

scholarly journals Extracellular volume quantification using synthetic haematocrit assessed from native and post-contrast longitudinal relaxation T1 times of a blood pool

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lukas Opatril ◽  
Roman Panovsky ◽  
Jan Machal ◽  
Tomas Holecek ◽  
Lucia Masarova ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Relaxation Times ◽  
Extracellular Volume Fraction ◽  
Blood Pool ◽  
Coefficient Of Determination ◽  
Post Contrast ◽  
T1 Relaxation ◽  
Before And After

Abstract Background In terms of cardiovascular magnetic resonance are haematocrit values required for calculation of extracellular volume fraction (ECV). Previously published studies have hypothesized that haematocrit could be calculated from T1 blood pool relaxation time, however only native T1 relaxation time values have been used and the resulting formulae had been both in reciprocal and linear proportion. The aim of the study was to generate a synthetic haematocrit formula from only native relaxation time values first, calculate whether linear or reciprocal model is more precise in haematocrit estimation and then determine whether adding post-contrast values further improve its precision. Methods One hundred thirty-nine subjects underwent CMR examination. Haematocrit was measured using standard laboratory methods. Afterwards T1 relaxation times before and after the application of a contrast agent were measured and a statistical relationship between these values was calculated. Results Different linear and reciprocal models were created to estimate the value of synthetic haematocrit and ECV. The highest coefficient of determination was observed in the combined reciprocal model “− 0.047 + (779/ blood native) − (11.36/ blood post-contrast)”. Conclusions This study provides more evidence that assessing synthetic haematocrit and synthetic ECV is feasible and statistically most accurate model to use is reciprocal. Adding post-contrast values to the calculation was proved to improve the precision of the formula statistically significantly.

scholarly journals Extracellular Volume Quantification using Synthetic Haematocrit Assessed from Native and Post-contrast Longitudinal Relaxation T1 Times of a Blood Pool

2021 ◽  
Author(s):  
Lukas Opatril ◽  
Roman Panovsky ◽  
Jan Machal ◽  
Tomas Holecek ◽  
Lucia Masarova ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Relaxation Times ◽  
Extracellular Volume Fraction ◽  
Blood Pool ◽  
Coefficient Of Determination ◽  
Post Contrast ◽  
T1 Relaxation ◽  
Before And After

Abstract Background: In terms of cardiovascular magnetic resonance are haematocrit values required for calculation of extracellular volume fraction (ECV). Previously published studies have hypothesized that haematocrit could be calculated from T1 blood pool relaxation time, however only native T1 relaxation time values have been used and the resulting formulae had been both in reciprocal and linear proportion. The aim of the study was to generate a synthetic haematocrit formula from only native relaxation time values first, calculate whether linear or reciprocal model is more precise in haematocrit estimation and then determine whether adding post-contrast values further improve its precision.Methods: One hundred thirty-nine subjects underwent CMR examination. Haematocrit was measured using standard laboratory methods. Afterwards T1 relaxation times before and after the application of a contrast agent were measured and a statistical relationship between these values was calculated.Results: Different linear and reciprocal models were created to estimate the value of synthetic haematocrit and ECV. The highest coefficient of determination was observed in the combined reciprocal model “-0.047 + (779/ blood native) – (11.36/ blood post-contrast)”.Conclusions: This study provides more evidence that assessing synthetic haematocrit and synthetic ECV is feasible and statistically most accurate model to use is reciprocal. Adding post-contrast values to the calculation was proved to improve the precision of the formula statistically significantly.

Transmural heterogeneity of diffusion anisotropy in the sheep myocardium characterized by MR diffusion tensor imaging

2007 ◽  
Vol 293 (4) ◽  
pp. H2377-H2384 ◽  
Author(s):  
Yi Jiang ◽  
Julius M. Guccione ◽  
Mark B. Ratcliffe ◽  
Edward W. Hsu
Keyword(s):  
Diffusion Tensor Imaging ◽  
Volume Fraction ◽  
Diffusion Tensor ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Left Ventricular ◽  
Fiber Direction ◽  
Significant Difference ◽  
Mr Diffusion ◽  
Mr Diffusion Tensor Imaging

The orientation of MRI-measured diffusion tensor in the myocardium has been directly correlated to the tissue fiber direction and widely characterized. However, the scalar anisotropy indexes have mostly been assumed to be uniform throughout the myocardial wall. The present study examines the fractional anisotropy (FA) as a function of transmural depth and circumferential and longitudinal locations in the normal sheep cardiac left ventricle. Results indicate that FA remains relatively constant from the epicardium to the midwall and then decreases (25.7%) steadily toward the endocardium. The decrease of FA corresponds to 7.9% and 12.9% increases in the secondary and tertiary diffusion tensor diffusivities, respectively. The transmural location of the FA transition coincides with the location where myocardial fibers run exactly circumferentially. There is also a significant difference in the midwall-endocardium FA slope between the septum and the posterior or lateral left ventricular free wall. These findings are consistent with the cellular microstructure from histological studies of the myocardium and suggest a role for MR diffusion tensor imaging in characterization of not only fiber orientation but, also, other tissue parameters, such as the extracellular volume fraction.

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