Fellows’ Journal Club: Intravoxel Incoherent Motion MR Imaging of Pediatric Intracranial Tumors: Correlation with Histology and Diagnostic Utility

Fellows’ Journal Club

Between April 2013 and September 2015, seventeen children with intracranial tumors were included in this retrospective study. Intravoxel incoherent motion parameters were fitted using 13 b-values for a biexponential model. The perfusion-free diffusion coefficient, pseudodiffusion coefficient, and perfusion fraction were measured in high- and low-grade tumors. The authors found significant correlations between the histology and IVIM parameters of different pediatric intracranial tumors. These results suggest that IVIM imaging reflects cell density and vascularity across different types of pediatric brain tumors. They also demonstrated that both the diffusion and perfusion parameters measured on IVIM imaging are useful for grading intracranial neuroectodermal tumors in pediatric patients.

Abstract

BACKGROUND AND PURPOSE

Images from an 11-year-old boy with histologically defined classic medulloblastoma (WHO grade IV). A, T2WI shows a heterogeneous, hyperintense mass in the vermis.

Intravoxel incoherent motion imaging, which simultaneously measures diffusion and perfusion parameters, is promising for brain tumor grading. However, intravoxel incoherent motion imaging has not been tested in children. The purpose of this study was to evaluate the correlation between intravoxel incoherent motion parameters and histology to assess the accuracy of intravoxel incoherent motion imaging for pediatric intracranial tumor grading.

MATERIALS AND METHODS

Between April 2013 and September 2015, 17 children (11 boys, 6 girls; 2 months to 15 years of age) with intracranial tumors were included in this retrospective study. Intravoxel incoherent motion parameters were fitted using 13 b-values for a biexponential model. The perfusion-free diffusion coefficient, pseudodiffusion coefficient, and perfusion fraction were measured in high- and low-grade tumors. These intravoxel incoherent motion parameters and the ADC were compared using the unpaired t test. The correlations between the intravoxel incoherent motion parameters and microvessel density or the MIB-1 index were analyzed using the Spearman correlation test. Receiver operating characteristic analysis was used to evaluate diagnostic performance.

RESULTS

The perfusion-free diffusion coefficient and ADC were lower in high-grade than in low-grade tumors (perfusion-free diffusion coefficient, 0.85 ± 0.40 versus 1.53 ± 0.21 × 10−3 mm2/s, P < .001; ADC, 1.04 ± 0.33 versus 1.60 ± 0.21 × 10−3 mm2/s, P < .001). The pseudodiffusion coefficient showed no difference between the groups. The perfusion fraction was higher in high-grade than in low-grade tumors (21.7 ± 8.2% versus 7.6 ± 4.3%, P < .001). Receiver operating characteristic analysis found that the combined perfusion-free diffusion coefficient and perfusion fraction had the best diagnostic performance for tumor differentiation (area under the curve = 0.986).

CONCLUSIONS

Intravoxel incoherent motion imaging reflects tumor histology and may be a helpful, noninvasive method for pediatric intracranial tumor grading.

Read this article: http://bit.ly/2JY6kHC

Fellows’ Journal Club: Intravoxel Incoherent Motion MR Imaging of Pediatric Intracranial Tumors: Correlation with Histology and Diagnostic Utility
Tags:
AJNR Editorial Office
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