Detection of intracranial hemorrhage: comparison between gradient-echo images and b(0) images obtained from diffusion-weighted echo-planar sequences.
AJNR Am J Neuroradiol
; 22(7): 1275-81, 2001 Aug.
Article
em En
| MEDLINE
| ID: mdl-11498414
ABSTRACT
BACKGROUND AND PURPOSE:
Diffusion-weighted MR imaging (DWI) is commonly used as the initial and sole imaging examination for the detection of acute cerebral infarction, yet it remains controversial whether MR can detect hyperacute (<24 h) hemorrhage. Hemorrhage is best detected with gradient-echo (GRE) T2*-weighted sequences, because of their magnetic susceptibility effects. DWI uses a spin-echo echo-planar technique (EPI) that is more sensitive than spin-echo T2-weighted imaging to susceptibility effects. Our aim was to determine whether the b(0) image from the DWI-EPI sequence is as sensitive as GRE in detecting hemorrhagic lesions on imaging studies performed to identify acute infarction or hemorrhage.METHODS:
All MR studies performed for clinically suspected or radiographically confirmed acute infarction or hemorrhage from 2/1/98 to 8/15/99 were retrospectively interpreted by one neuroradiologist in a blinded fashion. The sensitivity of hemorrhage detection, conspicuity of lesions, and diagnostic certainty were compared between the b(0) EPI and GRE sequences.RESULTS:
We found 101 acute infarcts, of which 13 were hemorrhagic, as evidenced by the presence of hypointensity within the infarction on the GRE sequence. This finding served as the reference standard for detection of hemorrhage. Hemorrhage was diagnosed with confidence in only seven cases (54%) on b(0) images; 22 acute hematomas were hypointense on GRE images whereas 19 were hypointense on b(0) images (86%); 17 chronic hematomas were depicted on GRE images and 12 on b(0) scans (63%). Punctate hemorrhages and linear cortical staining were detected on 37 GRE studies but on only four b(0) studies. Hemorrhage was always more conspicuous on the GRE sequences.CONCLUSION:
b(0) images from a DWI sequence failed to detect minimally hemorrhagic infarctions and small chronic hemorrhages associated with microangiopathy. GRE scans were more sensitive than b(0) images in the detection of these hemorrhages and should be included in emergency brain MR studies for acute infarction, especially when thrombolytic therapy is contemplated.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Aumento da Imagem
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Hemorragia Cerebral
/
Imagem Ecoplanar
Tipo de estudo:
Diagnostic_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
AJNR Am J Neuroradiol
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos