Diffusion-weighted imaging with dual-echo echo-planar imaging for better sensitivity to acute stroke.
AJNR Am J Neuroradiol
; 35(7): 1293-302, 2014 Jul.
Article
in En
| MEDLINE
| ID: mdl-24763417
ABSTRACT
BACKGROUND AND PURPOSE:
Parallel imaging facilitates the acquisition of echo-planar images with a reduced TE, enabling the incorporation of an additional image at a later TE. Here we investigated the use of a parallel imaging-enhanced dual-echo EPI sequence to improve lesion conspicuity in diffusion-weighted imaging. MATERIALS ANDMETHODS:
Parallel imaging-enhanced dual-echo DWI data were acquired in 50 consecutive patients suspected of stroke at 1.5T. The dual-echo acquisition included 2 EPI for 1 diffusion-preparation period (echo 1 [TE = 48 ms] and echo 2 [TE = 105 ms]). Three neuroradiologists independently reviewed the 2 echoes by using the routine DWI of our institution as a reference. Images were graded on lesion conspicuity, diagnostic confidence, and image quality. The apparent diffusion coefficient map from echo 1 was used to validate the presence of acute infarction. Relaxivity maps calculated from the 2 echoes were evaluated for potential complementary information.RESULTS:
Echo 1 and 2 DWIs were rated as better than the reference DWI. While echo 1 had better image quality overall, echo 2 was unanimously favored over both echo 1 and the reference DWI for its high sensitivity in detecting acute infarcts.CONCLUSIONS:
Parallel imaging-enhanced dual-echo diffusion-weighted EPI is a useful method for evaluating lesions with reduced diffusivity. The long TE of echo 2 produced DWIs that exhibited superior lesion conspicuity compared with images acquired at a shorter TE. Echo 1 provided higher SNR ADC maps for specificity to acute infarction. The relaxivity maps may serve to complement information regarding blood products and mineralization.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain
/
Image Interpretation, Computer-Assisted
/
Image Enhancement
/
Echo-Planar Imaging
/
Stroke
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Diffusion Magnetic Resonance Imaging
/
Multimodal Imaging
Type of study:
Diagnostic_studies
Limits:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
AJNR Am J Neuroradiol
Year:
2014
Document type:
Article