scholarly journals Non-parametric deconvolution using Bézier curves for quantification of cerebral perfusion in dynamic susceptibility contrast MRI

2022 ◽  
Author(s):  
Arthur Chakwizira ◽  
André Ahlgren ◽  
Linda Knutsson ◽  
Ronnie Wirestam
Keyword(s):  
Signal To Noise Ratio ◽  
Mean Transit Time ◽  
Residue Function ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Bezier Curves ◽  
Bézier Curves ◽  
Dynamic Susceptibility Contrast Mri ◽  
Dsc Mri ◽  
Susceptibility Contrast

Abstract Objective Deconvolution is an ill-posed inverse problem that tends to yield non-physiological residue functions R(t) in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI). In this study, the use of Bézier curves is proposed for obtaining physiologically reasonable residue functions in perfusion MRI. Materials and methods Cubic Bézier curves were employed, ensuring R(0) = 1, bounded-input, bounded-output stability and a non-negative monotonically decreasing solution, resulting in 5 parameters to be optimized. Bézier deconvolution (BzD), implemented in a Bayesian framework, was tested by simulation under realistic conditions, including effects of arterial delay and dispersion. BzD was also applied to DSC-MRI data from a healthy volunteer. Results Bézier deconvolution showed robustness to different underlying residue function shapes. Accurate perfusion estimates were observed, except for boxcar residue functions at low signal-to-noise ratio. BzD involving corrections for delay, dispersion, and delay with dispersion generally returned accurate results, except for some degree of cerebral blood flow (CBF) overestimation at low levels of each effect. Maps of mean transit time and delay were markedly different between BzD and block-circulant singular value decomposition (oSVD) deconvolution. Discussion A novel DSC-MRI deconvolution method based on Bézier curves was implemented and evaluated. BzD produced physiologically plausible impulse response, without spurious oscillations, with generally less CBF underestimation than oSVD.

scholarly journals Intra-tumoural perfusion habitats showed prognostic value in glioblastoma patients

2019 ◽  
Vol 21 (Supplement_4) ◽  
pp. iv3-iv3
Author(s):  
Chao Li ◽  
Chang Sun ◽  
Shuo Wang ◽  
Stephen Price
Keyword(s):  
Cerebral Blood Volume ◽  
Cox Regression ◽  
Mean Transit Time ◽  
Tumour Microenvironment ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Post Contrast ◽  
Dsc Mri ◽  
Contrast Enhanced ◽  
Susceptibility Contrast

Abstract The perfusion within glioblastoma is associated with tumour microenvironment and may create invasive tumor habitats that could potentially be revealed by perfusion imaging. The purpose of this study is to characterize the peritumoural habitats of glioblastoma for treatment target. Dynamic susceptibility contrast-enhancement (DSC) MRI was acquired pre-operatively on 115 newly-diagnosed glioblastoma patients. All images were co-registered to post-contrast T1-weighted images. The relative cerebral blood volume (rCBV), mean transit time (MTT) and relative cerebral blood flow (rCBF) maps were generated from the DSC images. The contrast-enhanced and peritumoural tumor regions were semi-automatically segmented from the post-contrast T1-weighted and FLAIR images. To delineate the habitats of different perfusion levels, a two clusters mixture model with Gaussian distribution was fitted to the rCBV, rCBF, and MTT within both contrast-enhanced and peritumoural regions. Perfusion parameters of the identified habitats were compared, and the prognostic values of habitats were investigated using survival analysis. The results showed that although non-enhanced, the peritumoral high perfusion (PHP) habitat demonstrated similar perfusion level with the contrast high perfusion (CHP) habitat, with similar rCBV (PHP: 1.13 ± 0.18, 95% CI [1.10, 1.15]; CHP: 1.21 ± 0.25, 95% CI [1.16, 1.21]) and rCBF (PHP: 1.08 ± 0.23, 95% CI [1.05, 1.08]; CHP: 1.08 ± 0.19, 95% CI [1.05, 1.08]). Multivariate Cox regression showed that the volumes of both habitats were associated with worse patient overall survival (PHP: P = 0.032; HR= 7.09; CHP: P = 0.008; HR= 12.01). Our results suggest that the intra-tumoural perfusion habitats may potentially offer treatment targets.

Dexamethasone Normalizes Brain Tumor Hemodynamics as Indicated by Dynamic Susceptibility Contrast MRI Perfusion Parameters

2005 ◽  
Vol 4 (3) ◽  
pp. 245-249 ◽  
Author(s):  
Christopher C. Quarles ◽  
Hendrikus G. J. Krouwer ◽  
Scott D. Rand ◽  
Kathleen M. Schmainda
Keyword(s):  
Transit Time ◽  
Spin Echo ◽  
Mean Transit Time ◽  
Normal Brain ◽  
Post Inoculation ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Functional Changes ◽  
Dsc Mri ◽  
Susceptibility Contrast

The purpose of this study is to demonstrate the utility of dynamic susceptibility contrast (DSC) MRI-derived perfusion parameters to characterize the hemodynamic effects of dexamethasone in a 9L gliosarcoma tumor model. Twenty-four rats underwent intracerebral inoculation with 9L tumor cells. Fifteen were treated with a total of 3mg/kg of dexamethasone on days 10–14 post-inoculation, while the remaining 9 rats served as controls. Fourteen days post-inoculation, MRI images, sensitive to total and micro-vascular cerebral blood flow (CBF), mean transit time (MTT), and intravoxel transit time distributions (TTD)s were obtained using a simultaneous gradient-echo(GE)/spin-echo(SE) DSC-MRI method. Dexamethasone-treated animals had a microvascular (SE) tumor CBF that was 45.9% higher ( p = 0.0008) and a MTT that was 47.8% lower ( p = 0.0005) than untreated animals. With treatment, there was a non-significant 91.3% increase in total (GE) vascular CBF ( p = 0.35), and a significant decrease in MTT (49.1%, p = 0.02). The total vascular and microvascular TTDs from the treated tumors were similar to normal brain, unlike the TTDs in the untreated tumors. These findings demonstrate that DSC-MRI perfusion methods can be used to non-invasively detect the morphological and functional changes in tumor vasculature that occur in response to dexamethasone treatment.

scholarly journals Heterogeneity of Cortical Lesions in Multiple Sclerosis: An MRI Perfusion Study

2012 ◽  
Vol 33 (3) ◽  
pp. 457-463 ◽  
Author(s):  
Denis Peruzzo ◽  
Marco Castellaro ◽  
Massimiliano Calabrese ◽  
Elisa Veronese ◽  
Francesca Rinaldi ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Cortical Neurons ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Small Population ◽  
Dynamic Susceptibility ◽  
Cortical Lesions ◽  
Dynamic Susceptibility Contrast ◽  
Dsc Mri ◽  
Susceptibility Contrast

In this study, dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI) was used to quantify the cerebral blood flow (CBF), the cerebral blood volume (CBV), and the mean transit time (MTT) and to analyze the changes in cerebral perfusion associated with the cortical lesions in 44 patients with relapsing-remitting multiple sclerosis. The cortical lesions showed a statistically significant reduction in CBF and CBV compared with the normal-appearing gray matter, whereas there were no significant changes in the MTT. The reduced perfusion suggests a reduction of metabolism because of the loss of cortical neurons. A small population of outliers showing an increased CBF and/or CBV has also been detected. The presence of hyperperfused outliers may imply that perfusion could evolve during inflammation. These findings show that perfusion is altered in cortical lesions and that DSC-MRI can be a useful tool to investigate more deeply the evolution of cortical lesions in multiple sclerosis.

Prolonged Mean Transit Time Detected by Dynamic Susceptibility Contrast Magnetic Resonance Imaging Predicts Cerebrovascular Reserve Impairment in Patients with Moyamoya Disease

2016 ◽  
Vol 42 (1-2) ◽  
pp. 131-138 ◽  
Author(s):  
Takayuki Kawano ◽  
Yuki Ohmori ◽  
Yasuyuki Kaku ◽  
Daisuke Muta ◽  
Ken Uekawa ◽  
...  
Keyword(s):  
Transit Time ◽  
Moyamoya Disease ◽  
Cerebral Artery ◽  
Mean Transit Time ◽  
Photon Emission ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Cerebrovascular Reserve ◽  
Dsc Mri ◽  
Susceptibility Contrast

Background: Evaluating cerebrovascular reserve (CVR) is important for patients with moyamoya disease (MMD). 123I-iodoamphetamine single-photon emission CT (SPECT) with acetazolamide (ACZ) challenge is widely carried out, but using ACZ becomes problematic owing to its off-label use and its adverse effects. Here, we report the efficacy of dynamic susceptibility contrast MRI (DSC-MRI) for the evaluation of CVR in MMD patients. Methods: All 33 MMD patients underwent both SPECT and DSC-MRI at an interval of <10 days from each other (mean age 38.3 years). The region of interest (ROI) was the anterior cerebral artery (ACA) territory, middle cerebral artery (MCA) territory, basal ganglia and cerebellum hemisphere for cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) images. The ratios of the ROIs to the ipsilateral cerebellum were calculated for each parameter and evaluated. The CVR was calculated using images acquired by SPECT before and after ACZ administration. The ratios of DSC-MRI parameters and CVR were compared and evaluated for each ROI. Results: The MTT of the ACA and MCA territories significantly correlated with CVR (p < 0.0001). However, CBF and CBV had no correlation with CVR. The MTT ratio had a threshold of 1.966, with a sensitivity of 68.4% and a specificity of 91.5% for predicting decreased CVR (<10%). Conclusion: MTT had a negative correlation with CVR. DSC-MRI is easy, safe and useful for detecting decreased CVR and can be used as a standard examination in MMD patient's care.

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