Identification of mineral deposits in the brain on radiological images: a systematic review.
OBJECTIVE
MRI has allowed the study of mineral deposition in the brain throughout life and in disease. However, studies differ in their reporting of minerals on MRI for reasons that are unclear.


METHODS
We conducted a systematic review from 1985 to July 2011 to determine the appearance of iron, calcium, copper and manganese on MRI and CT and their reliability. We assessed which imaging investigations provided the most consistent results compared with histology.


RESULTS
Of 325 papers on minerals imaging, we included 46 studies that confirmed findings either directly or indirectly using a non-imaging method such as histology. Within this group, there was inconsistency in the identification of iron probably because of changes in its paramagnetic properties during its degradation. Iron appeared consistently hypointense only on T2*-weighted MRI, and along with calcified areas, hyperattenuated on CT. Appearance of copper, calcium and manganese, although consistently reported as hyperintense on T1-weighted MRI, was confirmed histologically in few studies. On T2-weighted imaging, calcified areas were always reported as hypointense, while the appearance of iron depended on the concentration, location and degradation stage.


CONCLUSIONS
More work is required to improve the reliability of imaging methods to detect and differentiate brain mineral deposition accurately.


CONCLUSIONS
There is inconsistency in reporting the appearance of minerals on radiological images. • Only 46 studies confirmed mineral appearance using a non-imaging method. • Iron is the mineral more widely studied, consistently hypointense on T2*-weighted MRI. • T1-weighted MRI consistently reported copper, calcium and manganese hyperintense. • Calcium is consistently reported hypointense on T2-weighted MRI and hyperattenuating on CT.
Brain Research Imaging Centre, Department of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK. mvhernan@staffmail.ed.ac.uk
Maria del C
Mdel C
Valdés Hernández
Lucy C
LC
Maconick
Elizabeth M J
EM
Tan
Joanna M
JM
Wardlaw
D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology*; D002118:Calcium / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D003952:Diagnostic Imaging / Q000379:methods; D005293:Ferritins / Q000378:metabolism; D006485:Hemosiderin / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008345:Manganese / Q000737:chemistry; D008903:Minerals / Q000737:chemistry*; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods
D008903:Minerals; D008345:Manganese; D003300:Copper; D005293:Ferritins; D006485:Hemosiderin; D007501:Iron; D002118:Calcium