Intracranial haemorrhage on phase images of SWI (susceptibility weighted image)

Intracranial haemorrhage on phase images of SWI (susceptibility weighted image) Poster No.: C-1088 Congress: ECR 2014 Type: Scientific Exhibit Authors: Y. J. LEE, H. S. Choi, B.-Y. Kim, J. Jang, S. L. Jung, K. J. Ahn, B. S. Kim; Seoul/KR Keywords: Neuroradiology brain, MR, CT, Outcomes analysis, Hemorrhage DOI: 10.1594/ecr2014/C-1088 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 10

Aims and objectives Susceptibility weighted imaging (SWI) can exploit the magnetic susceptibility differences of various tissues. SWI is more sensitive in detection of susceptibility effects and depicts significantly more small hemorrhagic lesions than does the conventional GRE sequence. Intracranial hemorrhage (ICH) looks dark blooming on SWI. However, pattern of ICH on phase images has not been well known. The purpose of this study is to characterize hemorrhagic lesions on phase images of SWI. Methods and materials We retrospectively enrolled patients with ICH who underwent both SWI and precontrast CT between 2011 and 2013 (n=43).swi was taken using 3-Teslar system and phase map was generated after postprocessing. SWI was obtained with 3-dimensional gradient echo, according to the following parameters: FA=15, a repetition time(tr) of 28ms, an echo time(te) of 20 ms, a 320 x 320 acqusition matrix, a field of view of 23 x 23 cm, a slice thickness of 2 mm. Types of hemorrhage were determined and stages of hemorrhage were determined in correlation with precontrast CT, T1- and T2-weighted images, and FLAIR images. Types of hemorrhage is classified as subdural hemorrhage or epidural hemorrhage, subarachnoid hemorrhage, and parenchymal hemorrahge. Phase values of ICH were qualitatively evaluated: dark, gray, and bright. We summarized imaging feature of intracranial hemorrhage on phase map of SWI. Cases were reviewed by 8-year and 2-year experienced radiologists in consensus. Results Four types of hemorrhage are observed: subdural and epidural (acute, n=3; subacute, n=10; and chronic, n=4); subarachnoid (acute, n=5); parenchymal hemorrhage (acute, n=2; subacute, n=13); and microbleed (n=40). Subdural hemorrhage and epidural hemorrhage showed heterogeneous mixed bright and dark pattern in acute and early subacute stage; and homogeneous gray on phase images in late subacute and chronic stage. All acute subarachnoid hemorrhage showed bright on phase images without aliasing. All parenchymal hemorrhages more than 5-mm showed aliasing pattern on phase images regardless of hemorrhagic stage, but always showed bright on upper and lower most slices of ICH. Microbleeds between 3- and 5-mm showed dipole artifact. However, microbleeds less than 3-mm showed no dipole artifact. Page 2 of 10

Images for this section: Fig. 1: Pattern of hemorrhage in phase image. Page 3 of 10

Fig. 2: Subdural hemorrhage(sdh) on CT and MRI with different values on phase image on 3 different stages. A, CT and MRI show acute SDH along the right cerebral convexity. Phase image shows heterogeneous mixed bright and dark value(arrows). B, CT and MRI show subacute SDH along left cerebral convexity. Phase image shows heterogeneous mixed bright and dark value(arrow). C, CT and MRI show late subacute to chronic stage of SDH along the both cerebral convexity(arrows). SWI shows iso signal(arrows). Phase image shows homogeneous gray value(arrows). Fig. 3: Sixty-one year old male patient with subarachnoid hemorrhage(sah). CT images show high attenuation along the sulci of right frontoparietal lobe, representing SAH. On Page 4 of 10

MRI, this lesion shows hyperintensities on T2 FLAIR. Phase image shows bright value without aliasing. SWI shows hemorrhagic signal along sulci of right frontoparietal lobe. Fig. 4: All parenchymal hemorrhages more than 5-mm showed aliasing pattern on phase images regardless of hemorrhagic stage.and These lesions always shows bright on upper and lower most slices of parenchymal hemorrhage. On CT, high attenuation more than 5-mm is noted in left parietal region, representing parenchymal hemorrhage. This lesion show aliasing pattern on phase images. Page 5 of 10

Fig. 5: Other cases more than 5-mm parenchymal hemorrhage on 3 different patients also show aliasing pattern on phase image. A, T2 FLAIR images show hemorrhage with perilesional edema in right frontal lobe precentral region with aliasing pattern on phase image(arrow). B, T2 FLAIR images show hemorrhage with perilesional edema in left temporo-occipital lobe with aliasing pattern on phase image(arrow). C, T2 FLAIR images show hemorrhage in left frontal lobe with aliasing pattern on phase image(arrow). Page 6 of 10

Fig. 6: Sixty-eight year old male patient with multifocal hemorrhagic brain contusion involving both cerebral hemispheres. A, CT and MRI show parenchymal hemorrhage in right frontal lobe. SWI shows dark signal in the lesion. B, On phase images, upper most slices(left end image) and lower most slices(right end image)of ICH always show bright value. Page 7 of 10

Fig. 7: A seventy-one year old female patient with microbleed between 3-mm and 5-mm in right thalamus. A, SWI shows a dark signal in right thalamus(arrow). B, Phase images, upper(top), middle, lower(bottom) slice of this lesion show bright in upper and lower pole, and dark in equator.this lesion shows dipole artifact on phase image. Page 8 of 10

Fig. 8: Eighty-one year old female with microbleed less than 3-mm without dipole artifact in both cerebral hemisphere. A, SWI shows three dark signal in both parietal lobe. B, Phase image shows bright value in corresponding with lesions on SWI. Upper and lower most slices of the lesion show bright, so microbleed less than 3-mm show no dipole artifact on phase image. Page 9 of 10

Conclusion Calcification can be differentiated from hemorrhage on phase images on the basis of differences in susceptibility effects. Other clinical application of phase images,more recently, researchers have shown that changes in iron content of the brain can be monitored by using phase images. But, pattern of ICH on phase images has not been well known, as dark blooming pattern. In our hospital, pattern of hemorrhage in phase images of SWI showed variable difference according to type, stage, and size. Personal information Y. J. LEE, H. S. Choi, B.-Y. Kim, J. Jang, S. L. Jung, K. J. Ahn, B. S. Kim; Seoul/KR mail to: yoondori5678@gmail.com References Mohamed Masoud Radwan, Reda A. Darwish, Abd El Aziz M.El Nekiedy, Sherif A.Shama. Role of magnetic susceptibility weighted imaging in evaluation of brain lesions. Alexandria Journal of Medicine 2011;47:299-308. E.M. Haacke, S.Mittal, Z.Wu, J.Neelavalli, Y.-C.N. Cheng. Susceptibilityweighted imaging: technical aspects and clinical applications, part 1. AJNR AM J Neuroradiol. 2009 Jan 30:19-30 S.Mittal, Z.Wu, J.Neelavalli, E.M. Haacke. Susceptibility-weighted imaging: technical aspects and clinical applications, part 2. AJNR AM J Neuroradiol. 2009 Feb 30:232-52 Govind B. Chavhan, Paul S.Babyn, Bejoy Thomas, Manohar M.Shroff, E. Mark Haacke. Principles, techniques, and applications of T2*-based MR Imaging and its special applications.radiographics.2009 September; 29(5): 1433-1449. Page 10 of 10