Premium
Simultaneous imaging of radiation‐induced cerebral microbleeds, arteries and veins, using a multiple gradient echo sequence at 7 Tesla
Author(s) -
Bian Wei,
Banerjee Suchandrima,
Kelly Douglas A.C.,
Hess Christopher P.,
Larson Peder E.Z.,
Chang Susan M.,
Nelson Sarah J.,
Lupo Janine M.
Publication year - 2015
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24802
Subject(s) - gradient echo , medicine , nuclear medicine , spin echo , susceptibility weighted imaging , magnetic resonance imaging , echo (communications protocol) , magnetic resonance angiography , angiography , radiology , nuclear magnetic resonance , physics , computer science , computer network
Background The purpose of this study was to implement and evaluate the utility of a multi‐echo sequence at 7 Tesla (T) for simultaneous time‐of‐flight (TOF) MR‐angiography (MRA) and susceptibility‐weighted imaging (SWI) of radiation‐induced cerebral microbleeds (CMBs), intracranial arteries, and veins. Methods A four‐echo gradient‐echo sequence was implemented on a 7T scanner. The first echo was used to create TOF‐MRA images, while the remaining echoes were combined to visualize CMBs and veins on SWI images. The sequence was evaluated on eight brain tumor patients with known radiation‐induced CMBs. Single‐echo images were also acquired to visually and quantitatively compare the contrast‐to‐noise ratio (CNR) of small‐ and intermediate‐vessels between acquisitions. The number of CMBs detected with each acquisition was also quantified. Statistical significance was determined using a Wilcoxon signed‐rank test. Results Compared with the single‐echo sequences, the CNR of small and intermediate arteries increased 7.6% ( P < 0.03) and 9.5% ( P = 0.06), respectively, while the CNR of small and intermediate veins were not statistically different between sequences ( P = 0.95 and P = 0.46, respectively). However, these differences were not discernible by visual inspection. Also the multi‐echo sequence detected 18.3% more CMBs ( P < 0.008) due to higher slice resolution. Conclusion The proposed 7T multi‐echo sequence depicts arteries, veins, and CMBs on a single image to facilitate quantitative evaluation of radiation‐induced vascular injury. J. Magn. Reson. Imaging 2015;42:269–279.