Abstract
Purpose: To describe a rapid T2*-weighted (T2*W), three-dimensional (3D) echo planar imaging (EPI) sequence and its application in mapping local magnetic susceptibility variations in 3 Tesla (T) prostate MRI. To compare the sensitivity of T2*W EPI with routinely used T1-weighted turbo-spin echo sequence (T1W TSE) in detecting hemorrhage and the implications on sequences sensitive to field inhomogeneities such as MR spectroscopy (MRS). Materials and Methods: B0 susceptibility weighted mapping was performed using a 3D EPI sequence featuring a 2D spatial excitation pulse with gradients of spiral k-space trajectory. A series of 11 subjects were imaged using 3T MRI and combination endorectal (ER) and six-channel phased array cardiac coils. T1W TSE and T2*W EPI sequences were analyzed quantitatively for hemorrhage contrast. Point resolved spectroscopy (PRESS MRS) was performed and data quality was analyzed. Results: Two types of susceptibility variation were identified: hemorrhagic and nonhemorrhagic T2*W-positive areas. Post-biopsy hemorrhage lesions showed on average five times greater contrast on the T2*W images than T1W TSE images. Six nonhemorrhage regions of severe susceptibility artifact were apparent on the T2*W images that were not seen on standard T1W or T2W images. All non-hemorrhagic susceptibility artifact regions demonstrated compromised spectral quality on 3D MRS. Conclusion: The fast T2*W EPI sequence identifies hemorrhagic and nonhemorrhagic areas of susceptibility variation that may be helpful in prostate MRI planning at 3.0T.
Original language | English (US) |
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Pages (from-to) | 902-907 |
Number of pages | 6 |
Journal | Journal of Magnetic Resonance Imaging |
Volume | 33 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2011 |
Externally published | Yes |
Keywords
- MRI
- Magnetic resonance spectroscopy
- Prostate cancer
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging