A comparison of images generated from diffusion-weighted and diffusion-tensor imaging data in hyper-acute stroke.

Area of Science:

• Neuroimaging
• Radiology
• Medical Physics

Background:

• Hyper-acute stroke detection is critical for timely intervention.
• Magnetic Resonance Imaging (MRI) techniques, including Diffusion-Weighted Imaging (DWI) and Diffusion Tensor Imaging (DTI), are used for stroke assessment.
• Fast acquisition strategies (under one minute) are desirable for clinical efficiency.

Purpose of the Study:

• To compare the effectiveness of isotropic and anisotropic diffusion imaging parameters in detecting hyper-acute ischemic stroke.
• To evaluate fast MR DWI and DTI acquisition strategies for early stroke detection.

Main Methods:

• Analyzed 21 ischemic stroke patients imaged within six hours of symptom onset using both DWI and DTI.
• Calculated percent difference in image intensity for nine generated diffusion images (isotropic and anisotropic) in ischemic lesions and normal tissue.

Main Results:

• Isotropic strategies showed significant changes; isotropically-weighted diffusion image (isoDWI) had a 50.7% difference (P < 0.001).
• Apparent diffusion coefficient (ADC) maps demonstrated the most significant difference (-42.4%, P < 0.001).
• No anisotropic images (relative anisotropy [RA], fractional anisotropy [FA], volume ratio [VR]) showed significant differences in the hyper-acute phase.

Conclusions:

• Isotropic diffusion imaging, particularly DWI, is more suitable for detecting hyper-acute ischemic stroke within the first six hours.
• Anisotropic images may be valuable for differentiating hyper-acute stroke from acute and sub-acute stroke stages.