Quantitative Magnetic Resonance Diffusion-Weighted Imaging Evaluation of the Supratentorial Brain Regions in Patients Diagnosed with Brainstem Variant of Posterior Reversible Encephalopathy Syndrome: A Preliminary Study.
OBJECTIVE
Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity with several causes, characterized by rapid onset of symptoms and typical neuroimaging features, which usually resolve if promptly recognized and treated. Brainstem variant of PRES presents with vasogenic edema in brainstem regions on magnetic resonance (MR) images and there is sparing of the supratentorial regions. Because PRES is usually caused by a hypertensive crisis, which would likely have a systemic effect and global manifestations on the brain tissue, we thus proposed that some microscopic abnormalities of the supratentorial regions could be detected with diffusion-weighted imaging (DWI) using apparent diffusion coefficient (ADC) analysis in brainstem variant of PRES and hypothesized that "normal-looking" supratentorial regions will increase water diffusion.


METHODS
We retrospectively identified patients with PRES who underwent brain magnetic resonance imaging studies. We identified 11 brainstem variants of PRES patients, who formed the study cohort, and 11 typical PRES patients and 20 normal control subjects as the comparison cohorts for this study. Nineteen regions of interest were drawn and systematically placed. The mean ADC values were measured and compared among these 3 groups.


RESULTS
ADC values of the typical PRES group were consistently elevated compared with those in normal control subjects. ADC values of the brainstem variant group were consistently elevated compared with those in normal control subjects. ADC values of the typical PRES group and brainstem variant group did not differ significantly, except for the pons area.


CONCLUSIONS
Quantitative MR DWI may aid in the evaluation of supratentorial microscopic abnormalities in brainstem variant of PRES patients.
Section of Neuroradiology, Department of Medical Imaging, Chi-Mei Medical Center, Tainan, Taiwan; Graduate Institute of Medical Sciences, Chang Jung Christian University, Tainan, Taiwan. Electronic address: taiyuanc@mail.cjcu.edu.tw.
Tai-Yuan
TY
Chen
Section of Neuroradiology, Department of Medical Imaging, Chi-Mei Medical Center, Tainan, Taiwan; Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
Te-Chang
TC
Wu
Section of Neuroradiology, Department of Medical Imaging, Chi-Mei Medical Center, Tainan, Taiwan; Institute of Biomedical Science, National Sun Yat-Sen University, Kaohsiung, Taiwan.
Ching-Chung
CC
Ko
Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan.
I-Jung
IJ
Feng
Section of Neuroradiology, Department of Medical Imaging, Chi-Mei Medical Center, Tainan, Taiwan.
Yu-Kun
YK
Tsui
Section of Neuroradiology, Department of Medical Imaging, Chi-Mei Medical Center, Tainan, Taiwan.
Chien-Jen
CJ
Lin
Department of Radiology, E-DA Hospital, I-Shou University, Kaohsiung, Taiwan; Center for Functional Onco-Imaging of Radiological Sciences, School of Medicine, University of California, Irvine, California.
Jeon-Hor
JH
Chen
Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan; Institute of Neuroscience, School of Life Science, National Yang-Ming University, Taipei, Taiwan.
Ching-Po
CP
Lin
D000328:Adult; D001929:Brain Edema / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001933:Brain Stem / Q000000981:diagnostic imaging* / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D054038:Posterior Leukoencephalopathy Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D000074286:Preliminary Data; D012189:Retrospective Studies
Diffusion-weighted imaging (DWI); apparent diffusion coefficient (ADC); brainstem variant of posterior reversible encephalopathy syndrome; posterior reversible encephalopathy syndrome (PRES)