Open AccessBrain MRI with Quantitative Susceptibility Mapping: Relationship to CT Attenuation Values
Author(s) -
Sonoko Oshima,
Yasutaka Fushimi,
Tomohisa Okada,
K. Takakura,
Chunlei Liu,
Yusuke Yokota,
Yoshiki Arakawa,
Nobukatsu Sawamoto,
Susumu Miyamoto,
Kaori Togashi
Publication year - 2020
Publication title -
radiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.118
H-Index - 295
eISSN - 1527-1315
pISSN - 0033-8419
DOI - 10.1148/radiol.2019182934
Subject(s) - quantitative susceptibility mapping , medicine , putamen , dentate nucleus , globus pallidus , nuclear medicine , caudate nucleus , magnetic resonance imaging , attenuation , imaging phantom , nuclear magnetic resonance , radiology , basal ganglia , central nervous system , physics , optics , cerebellum
Background Quantitative susceptibility mapping (QSM) is used to differentiate between calcification and iron deposits. Few studies have examined the relationship between CT attenuation values and magnetic susceptibility in such materials. Purpose To assess the relationship among metal concentration, CT attenuation values, and magnetic susceptibility in paramagnetic and diamagnetic phantoms, and the relationship between CT attenuation values and susceptibility in brain structures that have paramagnetic or diamagnetic properties. Materials and Methods In this retrospective study, CT and MRI with QSM were performed in gadolinium and calcium phantoms, patients, and healthy volunteers between June 2016 and September 2017. In the phantom study, we evaluated correlations among metal concentration, CT attenuation values, and susceptibility. In the human study, Pearson and Spearman correlations were performed to assess the relationship between CT attenuation values and susceptibility in regions of interest placed in the globus pallidus (GP), putamen, caudate nucleus, substantia nigra, red nucleus, dentate nucleus, choroid plexus, and hemorrhagic and calcified lesions. Results Eighty-four patients (mean age, 64.8 years ± 19.6; 49 women) and 20 healthy volunteers (mean age, 72.0 years ± 7.6; 11 men) were evaluated. In the phantoms, strong linear correlations were identified between gadolinium concentration and CT and MRI QSM values ( R 2 = 0.95 and 0.99, respectively; P < .001 for both) and between calcium concentration and CT and MRI QSM values ( R 2 = 0.89 [ P = .005] and R 2 = 0.98 [ P < .001], respectively). In human studies, positive correlations between CT attenuation values and susceptibility were observed in the GP ( R 2 = 0.52, P < .001) and in hemorrhagic lesions ( R 2 = 0.38, P < .001), and negative correlations were found in the choroid plexus ( R 2 = 0.53, P < .001) and in calcified lesions ( R 2 = 0.38, P = .009). Conclusion CT attenuation values showed a positive correlation with susceptibility in the globus pallidus and hemorrhagic lesions and negative correlation in the choroid plexus and calcified lesions. © RSNA, 2020 Online supplemental material is available for this article.