Clinical applications of susceptibility weighted MR imaging of the brain - a pictorial review.
BACKGROUND
Susceptibility-weighted imaging (SWI) is a novel magnetic resonance (MR) technique that exploits the magnetic susceptibility differences of various tissues, such as blood, iron and calcification. This pictorial review covers many clinical conditions illustrating its usefulness.


METHODS
SWI consists of using both magnitude and phase images from a high-resolution, three-dimensional fully velocity-compensated gradient echo sequence. Phase mask is created from the MR phase images, and multiplying these with the magnitude images increase the conspicuity of the smaller veins and other sources of susceptibility effects, which is depicted using minimal intensity projection (minIP).


RESULTS
The phase images are useful in differentiating between diamagnetic and paramagnetic susceptibility effects of calcium and blood, respectively. This unique MR sequence will help in detecting occult low flow vascular lesions, calcification and cerebral microbleed in various pathologic conditions and aids in characterizing tumors and degenerative diseases of the brain. This sequence also can be used to visualize normal brain structures with conspicuity.


CONCLUSIONS
Susceptibility-weighted imaging is useful in differentiating and characterizing diverse brain pathologies.
Thomas
Bejoy
B
Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India. drbejoy2002@yahoo.com
Somasundaram
Sivaraman
S
Thamburaj
Krishnamoorthy
K
Kesavadas
Chandrasekharan
C
Gupta
Arun Kumar
AK
Bodhey
Narendra K
NK
Kapilamoorthy
Tirur Raman
TR
D001927:Brain Diseases / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging