Review new theories regarding the physiopathology of the Posterior Reversible Encephalopathy Syndrome (PRES) Correlate those with the radiologic findings,
with emphasis on MRI and its advanced techniques Perform a differential diagnosis with other entities that mimic its clinical presentation
DEFINITION Posterior reversible encephalopathy syndrome (PRES) have always been described as a neurological syndrome due to neurotoxicity recognized in a variety of ethiological conditions (hypertension,
characterised by a variety of symptoms,
and with the classic imaging finding being vasogenic edema in the subcortical white matter of the posterior territories (parietal and occipital lobe). Fig. 2 In fact,
its real definition is complex,
Findings and procedure details
Hypoperfusion due to blood-brain barrier damage is demonstrated as vasogenic edema in MRI,
which is the main finding in PRES and can be demonstrated in morphologic sequences (as hypointense on T1 and hyperintense on T2-weighted).
On unenhanced CT it’s hypoattenuated but can be very subtle and confused with grey-White matter interface. Fig. 8 Its distribution is variable,
but generally temporal and occipital lobes are affected in the subcortical white matter,
tipically in a bilateral and...
Radiologists must be aware of PRES’ change of paradigm (from hyper to hypoperfusion) to understand the imaging features seen in MRI and make differential diagnosis with other entities.
- Posterior Reversible Encephalopathy Syndrome.
Parts 1 and 2.
AJNR American Journal of Neuroradiology.
Jun-Jun 2008. - Utility and significance of Gadolinium-based contrast enhancement in posterior reversible encephalopathy syndromse.
AJNR 2016 - The many faces of posterior reversible encephalopathy syndrome.
BJR British Journal of Radiology,
25; 1566-1575 - PRES: Prognostic Utility of Quantitative Diffusion-Weighted images.
AJNR 2002; 23:1038-1048