Data Mining of MR Technical Parameters: A Case Study for SAR in a Large-Scale MR Repository

Data Mining of MR Technical Parameters: A Case Study for SAR in a Large-Scale MR Repository

Adriana Murraças, Paula Maria Vaz Martins, Carlos Daniel Cipriani Ferreira, Tiago Marques Godinho, Augusto Marques Ferreira da Silva
Copyright: © 2021 |Pages: 18
DOI: 10.4018/IJEHMC.2021010102
Article PDF Download
Open access articles are freely available for download

Abstract

Exposure to radiofrequency (RF) energy during a magnetic resonance imaging exam is a safety concern related to biological thermal effects. Estimation of the specific absorption rate (SAR) is done by manufacturer scanner integrated tools to monitor RF energy. This work presents an exploratory approach of DICOM metadata focused in whole-body SAR values, patient dependent parameters, and pulse sequences. Previously acquired abdominopelvic and head studies were retrieved from a 3 Tesla scanner. Dicoogle tool was used for metadata indexing, mining, and extraction. Specifically weighted pulse sequences were related with weight, BMI, and gender through boxplot diagrams and effect size analysis. A decrease of SAR values with increasing body weight and BMI categories is observable for abdominopelvic studies. Head studies showed different trends regarding distinct pulse sequences; in addition, underage patients register higher SAR values compared to adults. Male individuals register marginally higher SAR values. Metadata recording practices and standardization need to be improved.
Article Preview
Top

Background

Magnetic resonance (MR) is a widely used imaging modality with superior soft tissue contrast and flexible tools for diagnosis, physiological, and functional applications (Kim & Kim, 2017; Kraff & Ladd, 2016). In Europe, for the countries for which data is available, there was a general increase between 2011 and 2016 in the number of MR scans conducted relative to population size (Eurostat, 2019).

MR image acquisition does not use ionizing radiation and comprises an interaction between three types of magnetic fields with the human body: a high static magnetic field (B0), three gradient magnetic fields (Gx, Gy, and Gz), and a radiofrequency (RF) field (B1) (Hartwig, 2015). The timing of application of gradients and RF pulses is determined in a MR pulse sequence (pSq). There are two fundamental types of MR pSq: spin echo (SE) and gradient echo (GRE); other MR sequences are variations of these, with different parameters added on (Bitar et al., 2006). MR is considered a safe technology but is not hazard-free.

Complete Article List

Search this Journal:
Reset
Volume 15: 1 Issue (2024): Forthcoming, Available for Pre-Order
Volume 14: 1 Issue (2023)
Volume 13: 5 Issues (2022): 4 Released, 1 Forthcoming
Volume 12: 6 Issues (2021)
Volume 11: 4 Issues (2020)
Volume 10: 4 Issues (2019)
Volume 9: 4 Issues (2018)
Volume 8: 4 Issues (2017)
Volume 7: 4 Issues (2016)
Volume 6: 4 Issues (2015)
Volume 5: 4 Issues (2014)
Volume 4: 4 Issues (2013)
Volume 3: 4 Issues (2012)
Volume 2: 4 Issues (2011)
Volume 1: 4 Issues (2010)
View Complete Journal Contents Listing