Diffusion-weighted signal patterns of intracranial haemorrhage.
Clin Radiol
; 70(8): 909-16, 2015 Aug.
Article
em En
| MEDLINE
| ID: mdl-26050534
ABSTRACT
The signal pattern of intracranial haemorrhage on diffusion-weighted imaging (DWI) as it evolves over time is rarely discussed due to the sensitivity of T2*-weighted sequences and the specificity of classic signal patterns on T1 and T2-weighted sequences. The DWI signal is strongly affected by the magnetic susceptibility of paramagnetic blood products and, therefore, is markedly hypointense in the same phases that demonstrate hypointensity on T2*-weighted sequences; however, hyperacute haemorrhage (oxyhaemoglobin-predominant clot) and late subacute haemorrhage (extracellular methaemoglobin) do not demonstrate T2* hypointensity. Moreover, T2*-weighted sequences are less sensitive to the presence of extra-axial haemorrhage than to intraparenchymal haemorrhage. At these stages of evolution, haemorrhage demonstrates high DWI signal in association with low ADC values, which may be more pronounced than even its corresponding fluid-attenuated inversion recovery (FLAIR) signal. DWI is useful for identifying hyperacute subarachnoid haemorrhage and as a problem-solving tool in challenging cases.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hemorragias Intracranianas
/
Imagem de Difusão por Ressonância Magnética
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Clin Radiol
Ano de publicação:
2015
Tipo de documento:
Article