QSM can distinguish hemosiderin from calcification in carotid atherosclerotic plaque: an ex vivo MRI study of carotid endarterectomy specimens

Motivation: In plaque MRI, low signal intensity on all contrast weightings has been diagnosed as calcification; however, it is possible that some hemosiderin deposits have been misdiagnosed as calcification. As QSM clearly distinguishes between paramagnetic and diamagnetic materials, it could be useful in distinguishing hemosiderin from calcifications. Goal(s): To demonstrate that QSM is useful for distinguishing hemosiderin from calcification in plaques. Approach: 24 carotid endarterectomy specimens were examined ex vivo using 3T MRI. We compared the signal intensities on conventional MRI and QSM with reference to pathology. Results: Hemosiderin and calcification, which had similar signals on conventional MRI contrast, were clearly distinguished using QSM. Impact: By using QSM, we can avoid misdiagnosing hemosiderin in atherosclerotic plaque as calcification.