Type:
Educational Exhibit
Keywords:
Drugs / Reactions, Acute, Education, MR, CT, Neuroradiology brain, CNS, Hypertension
Authors:
P. Faria João, M. Bousende, T. Palma; Amadora/PT
DOI:
10.1594/ecr2013/C-0512
Imaging findings OR Procedure details
Due to the lack of specificity of the clinical and laboratory findings,
Imaging plays a key role in the diagnosis and follow-up pf PRES.
This section describes the essential findings at Computed Tomography (CT) and Magnetic Ressonance (MR).
CT is often the first exam performed,
due to its wider availability and lesser cost.
Findings are commonly normal or unspecific.
It can be useful to rule out other pathologies (i.e hemorhagic infarction) and may provide useful information in repeated scans performed when MR is unavaiable or contraindicated (Fig.
1).
MR is the imaging modality of choice in the evaluation of PRES.
Vasogenic edema can be accurately demonstrated as as areas of hipersignal in T2-weighted images.
Fluid Attenuated Inversion Recovery (FLAIR) sequence increases the sensitivity in the the detection and follow-up of cortical and subcortical lesions (Fig.
2,
3,
4).
In patients with a high degree of clinical suspicion for PRES,
Difffusion Weighted Imaginging with the corresponding Apparent Diffusion Coeficient (ADC) map are essential as they allow distinction between vasogenic edema (which shows iso/hipersignal at DWI and ADC map) and citotoxic edema (hiposignal at the ADC map) (Fig.3).
The latter is indicator of irreversible ischemia,
so it is vital that signs of reversible damage are recognised and promptly treated.