scholarly journals One‐millimeter isotropic breast diffusion‐weighted imaging: Evaluation of a superresolution strategy in terms of signal‐to‐noise ratio, sharpness and apparent diffusion coefficient

2018 ◽  
Vol 81 (4) ◽  
pp. 2588-2599 ◽  
Author(s):  
Maya Delbany ◽  
Aurélien Bustin ◽  
Julie Poujol ◽  
Isabelle Thomassin‐Naggara ◽  
Jacques Felblinger ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Imaging ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Imaging Evaluation ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Noise Ratio

Signal-to-Noise Ratio importance in Apparent Diffusion Coefficient measurements using Diffusion-Weighted Echo-Planar-Imaging scans

2014 ◽  
Vol 4 (2) ◽  
pp. 517-525
Author(s):  
Cristiano Biagini ◽  
Martina De Michele ◽  
Andrea Pratesi ◽  
Francesco Mungai ◽  
Margherita Betti ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Signal To Noise Ratio ◽  
Planar Imaging ◽  
Signal To Noise ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Noise Ratio ◽  
Echo Planar

Purpose: To define experimental grounds for Apparent Diffusion Coefficient (ADC) measurements using Spin-Echo Diffusion-Weighted Echo-Planar (SE-DW-EPI) sequences, as a function of Signal-to-Noise Ratio (SNR).Methods: multiple multi-b SE-DW-EPI scans with the same parameters but the lipid suppression technique have been compared on water phantom with a 3T MRI equipment. The SNR has been estimated using the method of difference. Images have been analyzed manually, comparing the signal intensities at different b-values.Results: All measurements show a high repeatability and strong self-consistency. A significant dependence of the ADC on SNR has been shown, and its lowest limitto obtain reliable quantitative answers has been stated.Conclusion: ADC measurements in vivo must be carefully designed to avoid systematic errors during acquisition and post-processing due to low SNR.

scholarly journals Classification of paediatric brain tumours by diffusion weighted imaging and machine learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jan Novak ◽  
Niloufar Zarinabad ◽  
Heather Rose ◽  
Theodoros Arvanitis ◽  
Lesley MacPherson ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Posterior Fossa ◽  
Brain Tumours ◽  
Diffusion Weighted Imaging ◽  
Regions Of Interest ◽  
Apparent Diffusion Coefficients ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Paediatric Brain Tumours

AbstractTo determine if apparent diffusion coefficients (ADC) can discriminate between posterior fossa brain tumours on a multicentre basis. A total of 124 paediatric patients with posterior fossa tumours (including 55 Medulloblastomas, 36 Pilocytic Astrocytomas and 26 Ependymomas) were scanned using diffusion weighted imaging across 12 different hospitals using a total of 18 different scanners. Apparent diffusion coefficient maps were produced and histogram data was extracted from tumour regions of interest. Total histograms and histogram metrics (mean, variance, skew, kurtosis and 10th, 20th and 50th quantiles) were used as data input for classifiers with accuracy determined by tenfold cross validation. Mean ADC values from the tumour regions of interest differed between tumour types, (ANOVA P < 0.001). A cut off value for mean ADC between Ependymomas and Medulloblastomas was found to be of 0.984 × 10−3 mm2 s−1 with sensitivity 80.8% and specificity 80.0%. Overall classification for the ADC histogram metrics were 85% using Naïve Bayes and 84% for Random Forest classifiers. The most commonly occurring posterior fossa paediatric brain tumours can be classified using Apparent Diffusion Coefficient histogram values to a high accuracy on a multicentre basis.

scholarly journals The role of quantitative diffusion-weighted imaging in characterization of hypovascular liver lesions: A prospective comparison of intravoxel incoherent motion derived parameters and apparent diffusion coefficient

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247301
Author(s):  
Jelena Djokić Kovač ◽  
Marko Daković ◽  
Aleksandra Janković ◽  
Milica Mitrović ◽  
Vladimir Dugalić ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Liver Metastases ◽  
Diffusion Weighted Imaging ◽  
Intraclass Correlation ◽  
Intravoxel Incoherent Motion ◽  
Liver Lesions ◽  
Diffusion Weighted ◽  
Significant Difference ◽  
Apparent Diffusion

Background The utility of intravoxel incoherent motion (IVIM) related parameters in differentiation of hypovascular liver lesions is still unknown. Purpose The purpose of this study was to evaluate the value of IVIM related parameters in comparison to apparent diffusion coefficient (ADC) for differentiation among intrahepatic mass-forming cholangiocarcinoma (IMC), and hypovascular liver metastases (HLM). Methods Seventy-four prospectively enrolled patients (21 IMC, and 53 HLM) underwent 1.5T magnetic resonance examination with IVIM diffusion-weighted imaging using seven b values (0–800 s/mm2). Two independent readers performed quantitative analysis of IVIM-related parameters and ADC. Interobserver reliability was tested using a intraclass correlation coefficient. ADC, true diffusion coefficient (D), perfusion-related diffusion coefficient (D*), and perfusion fraction (ƒ) were compared among the lesions using Kruskal-Wallis H test. The diagnostic accuracy of each parameter was assessed by receiver operating characteristic (ROC) curve analysis. Results The interobserver agreement was good for ADC (0.802), and excellent for D, D*, and ƒ (0.911, 0.927, and 0.942, respectively). ADC, and D values were significantly different among IMC and HLM (both p < 0.05), while there was no significant difference among these lesions for ƒ and D* (p = 0.101, and p = 0.612, respectively). ROC analysis showed higher diagnostic performance of D in comparison to ADC (AUC = 0.879 vs 0.821). Conclusion IVIM-derived parameters in particular D, in addition to ADC, could help in differentiation between most common hypovascular malignant liver lesions, intrahepatic mass—forming cholangiocarcinoma and hypovascular liver metastases.

Sign in / Sign up

Export Citation Format

Share Document