Effects of MRI Protocol Parameters, Preload Injection Dose, Fractionation Strategies, and Leakage Correction Algorithms on the Fidelity of Dynamic-Susceptibility Contrast MRI Estimates of Relative Cerebral Blood Volume in Gliomas

Fellows’ Journal Club

The authors used DSC-MR imaging simulations to examine the influence of various acquisition parameters and leakage-correction strategies on the faithful estimation of CBV. Optimal strategies were determined by protocol with the lowest mean error. They conclude that the choice of image acquisition and preload dosing and/or fractionation has tremendous impact on the fidelity of CBV estimation. A variety of acquisition strategies can be used to obtain similar accuracy of CBV estimation, while the bidirectional leakage-correction algorithm aids in minimizing errors in CBV estimation under all scenarios.

Abstract

Figure 1 from paper
Effect of the flip angle on recovery of CBV (TE = 35 ms/TR = 1.0 second). A, Percentage error (with 95% CI) of the estimated CBV for different flip angles and leakage-correction strategies, without the use of preload, compared with ground truth CBV. B, Percentage error (with 95% CI) of the estimated CBV for different flip angles and leakage-correction strategies, with use of ¼ dose preload, compared with ground truth CBV.

BACKGROUND AND PURPOSE

DSC perfusion MR imaging assumes that the contrast agent remains intravascular; thus, disruptions in the blood-brain barrier common in brain tumors can lead to errors in the estimation of relative CBV. Acquisition strategies, including the choice of flip angle, TE, TR, and preload dose and incubation time, along with post hoc leakage-correction algorithms, have been proposed as means for combating these leakage effects. In the current study, we used DSC-MR imaging simulations to examine the influence of these various acquisition parameters and leakage-correction strategies on the faithful estimation of CBV.

MATERIALS AND METHODS

DSC-MR imaging simulations were performed in 250 tumors with perfusion characteristics randomly generated from the distributions of real tumor population data, and comparison of leakage-corrected CBV was performed with a theoretic curve with no permeability. Optimal strategies were determined by protocol with the lowest mean error.

RESULTS

The following acquisition strategies (flip angle/TE/TR and contrast dose allocation for preload and bolus) produced high CBV fidelity, as measured by the percentage difference from a hypothetic tumor with no leakage: 1) 35°/35 ms/1.5 seconds with no preload and full dose for DSC-MR imaging, 2) 35°/25 ms/1.5 seconds with ¼ dose preload and ¾ dose bolus, 3) 60°/35 ms/2.0 seconds with ½ dose preload and ½ dose bolus, and 4) 60°/35 ms/1.0 second with 1 dose preload and 1 dose bolus.

CONCLUSIONS

Results suggest that a variety of strategies can yield similarly high fidelity in CBV estimation, namely those that balance T1- and T2*-relaxation effects due to contrast agent extravasation.

Read this article: http://bit.ly/2nNHdfm

Effects of MRI Protocol Parameters, Preload Injection Dose, Fractionation Strategies, and Leakage Correction Algorithms on the Fidelity of Dynamic-Susceptibility Contrast MRI Estimates of Relative Cerebral Blood Volume in Gliomas
Jeffrey Ross
Fatal error: Uncaught Error: Call to undefined function get_cimyFieldValue() in /home2/ajnrblog/public_html/wp-content/themes/ample-child/author-bio.php:13 Stack trace: #0 /home2/ajnrblog/public_html/wp-content/themes/ample-child/content-single.php(35): include() #1 /home2/ajnrblog/public_html/wp-includes/template.php(812): require('/home2/ajnrblog...') #2 /home2/ajnrblog/public_html/wp-includes/template.php(745): load_template('/home2/ajnrblog...', false, Array) #3 /home2/ajnrblog/public_html/wp-includes/general-template.php(206): locate_template(Array, true, false, Array) #4 /home2/ajnrblog/public_html/wp-content/themes/ample/single.php(21): get_template_part('content', 'single') #5 /home2/ajnrblog/public_html/wp-includes/template-loader.php(106): include('/home2/ajnrblog...') #6 /home2/ajnrblog/public_html/wp-blog-header.php(19): require_once('/home2/ajnrblog...') #7 /home2/ajnrblog/public_html/index.php(17): require('/home2/ajnrblog...') #8 {main} thrown in /home2/ajnrblog/public_html/wp-content/themes/ample-child/author-bio.php on line 13