Double-shot magnetic resonance imaging of cerebral lesions: fast spin-echo versus echo planar sequences.
The authors compared two new rapid MRI techniques: double-shot echo-planar imaging (DS-EPI) versus double-shot fast spin-echo (DS-FSE) in the evaluation of cerebral lesions. The authors examined 35 patients with 37 lesions, which were hyperintense on long TR images. Patients were scanned with both DS-EPI and DS-FSE with a time of repetition (TR) of 10,000 milliseconds and an echo time (TE) of 80 milliseconds. Conspicuity was determined from region of interest measurements to calculate contrast to noise ratio (C/N). Visual comparisons between DS-EPI and DS-FSE, and between DS-EPI and T2-weighted conventional spin-echo (CSE) were also performed to evaluate the sequences' ability to depict hemorrhage. The mean C/N for both sequences was comparable: 36.7 for DS-FSE and 35.6 for DS-EPI, with no statistically significant difference (p = 0.77). With regards to depicting blood products, DS-EPI proved far more effective than DS-FSE and comparable to CSE. Also, DS-EPI proved to be more time-efficient, requiring 1.67 seconds per section, while DS-FSE required 3.33 seconds per section. Whereas DS-FSE and DS-EPI are comparable in their ability to depict hyperintense cerebral pathology, DS-EPI is more time-efficient, and therefore appears preferable. Because of the high magnetic susceptibility of DS-EPI, geometric distortion degrades visualization of lesions in the posterior fossa or near the sinuses. On the other hand, the high magnetic susceptibility results in high conspicuity of blood products.
Department of Radiology, New Jersey Medical School/University of Medicine and Dentistry of New Jersey, Newark 07103, USA.
L J
LJ
Wolansky
A I
AI
Holodny
M P
MP
Sheth
R
R
Axen
V
V
Prasad
D001921:Brain / Q000473:pathology; D001927:Brain Diseases / Q000175:diagnosis*; D001929:Brain Edema / Q000175:diagnosis; D001932:Brain Neoplasms / Q000175:diagnosis*; D017352:Echo-Planar Imaging; D006801:Humans; D007089:Image Enhancement; D012680:Sensitivity and Specificity