Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 197
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 197
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 271
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3165
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 597
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 511
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 317
Function: require_once
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Purpose: The clinical utility of conventional DCE-MRI methods is limited by the use of conventional qualitative dynamic T-weighted images, resulting in poor reproducibility. This study presents the initial implementation of a new DCE-magnetic resonance fingerprinting (DCE-MRF) methodology to provide reproducible, quantitative assessments of tumor vascular perfusion.
Methods: The DCE-MRF acquisition combines multiple T preparations, highly undersampled spiral trajectories (R = 48), a low-rank reconstruction method, and low tip angles on a 9.4 T preclinical MRI scanner to rapidly generate dynamic T maps (23-s temporal resolution). In vitro validation experiments were conducted across a range of Gadovist concentrations to assess accuracy and temporal precision in comparison to conventional methods. The DCE-MRF method was also evaluated in vivo in an orthotopic 4T1 mouse model of breast cancer (n = 25). Pharmacokinetic modeling of the in vivo data was performed using a linear reference region model (LRRM).
Results: In vitro DCE-MRF studies demonstrated good agreement with conventional MRI methods for T measurements (R 0.99). The iterative low-rank reconstruction method also reduced artifacts compared to conventional reconstruction methods. DCE-MRF demonstrated a 2- to 3-fold reduction in temporal variability compared to conventional DCE-MRI, and enabled effective in vivo pharmacokinetic modeling using the LRRM by generating voxelwise maps of RK and k as measures of tumor vascular perfusion.
Conclusions: DCE-MRF represents a new inherently quantitative approach to measuring tumor vascular perfusion that can be used in animal models and eventually in patients.
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http://dx.doi.org/10.1002/mrm.70019 | DOI Listing |