Feng Feng MD, Presenter: Nothing to Disclose

Hui You MD, Abstract Co-Author: Nothing to Disclose

Ling Hu MD,PhD, Abstract Co-Author: Nothing to Disclose

Han Wang MD, Abstract Co-Author: Nothing to Disclose

Jingjing Lu MD, Abstract Co-Author: Nothing to Disclose

Chunling Meng BS, Abstract Co-Author: Nothing to Disclose

Zheng Yu Jin, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Susceptibility-weighted imaging (SWI) consists of both magnitude and phase images from a high-resolution, three-dimensional, velocity compensated gradient-echo sequence. It exploits the magnetic properties of tissues, such as blood breakdown products or iron content. Iron deposition is believed to be involved in movement disorders, like idiopathic Parkinson disease (IPD) and multiple system atrophy (MSA-P). Our objective is to evaluate the role of SWI in the diagnosis of these disorders.

Axial 3-mm-thick FSE T2WI and 3D SWI were performed at the level of striatum in 19 patients with IPD and 12 patients with MSA-P by using a 3-Tesla MR scanner. The signal drop at globus pallidus and putamen on two sequences were evaluated by two neuroradiolgists with consensus. A hypointensity in the dorsolateral putamen equal to or lower than globus pallidus was taken into account as the main clue to differentiate these two diseases. Chi square test was used to compare SWI findings with FSE T2WI findings in the diagnosis of MSA.

Abnormal putaminal hypointensity was found in 10 of 12 patients with MSA-P (83.3% sensitivity) on SWI, while only 7 MSA-P patients showed abnormal putaminal hypointensity on FSE T2WI (58.3% sensitivity). 3 of 19 patients with IPD showed abnormal putaminal hypointensity (84.2% specificity) on SWI, while only 1 IPD patient showed abnormal putaminal hypointensity (95.0% specificity) on FSE T2WI. Although there was no statistical significance in detection of abnormal putaminal hypointensity between SWI and thin-slice FSE T2WI (p>0.05), 3D SWI allows a better depiction of mild abnormalities in putamen.

SWI is a valuable sequence in evaluating iron deposition in movement disorders. Further study on quantifying the intensity and volume of the deposition may be more helpful in the differential diagnosis of parkinsonism.

SWI is sensitive in detecting not only micro-bleeding, small venous malformation, but also iron deposition in neurodegenerative diseases.

Feng, F, You, H, Hu, L, Wang, H, Lu, J, Meng, C, Jin, Z, et al, , Susceptibility-weighted Imaging in Evaluation of Idiopathic Parkinson Disease and Multiple System Atrophy.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4433421.html