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Refocused turbo spin‐echo for noncontrast peripheral MR angiography
Author(s) -
Fielden Samuel W.,
Mugler John P.,
Hagspiel Klaus D.,
Norton Patrick T.,
Kramer Christopher M.,
Meyer Craig H.
Publication year - 2014
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24325
Subject(s) - fast spin echo , materials science , image quality , nuclear magnetic resonance , peripheral , radiology , magnetic resonance imaging , physics , medicine , artificial intelligence , computer science , image (mathematics)
Purpose To develop and assess a three‐dimensional refocused turbo spin‐echo (rTSE) sequence for generating peripheral angiograms. This sequence combines the rapid T 2 ‐weighting of TSE and the better flow performance of the fully‐refocused gradients of balanced steady state free precession (bSSFP), along with bSSFP‐style phase alternation of refocusing radiofrequency (RF) pulses. Materials and Methods The signal behavior generated by such a sequence was explored through Bloch equation simulations. The rTSE and TSE sequences were both used to generate peripheral angiograms in nine normal volunteers. The signal to noise ratio, contrast resolution, and vessel sharpness of the resulting images were used as bases for comparison. Additionally, the rTSE sequence was applied in four patients with peripheral artery disease to preliminarily assess its efficacy in a clinical setting through quality scoring by two experienced radiologists. Results The rTSE's RF phase alternation approach out‐performs a simple balanced‐gradient CPMG (Carr‐Purcell‐Meiboom‐Gill) ‐style TSE sequence in the presence of B 0 and B 1 inhomogeneities. In volunteers, the rTSE sequence yielded better arterial–venous contrast (0.378 ± 0.145 versus 0.155 ± 0.202; P < 0.01) and increased vessel sharpness (0.340 ± 0.034 versus 0.263 ± 0.034; P < 0.005) over TSE images. Stenoses visible in conventional angiographic images in patients were successfully imaged with the rTSE sequence; however, image quality scores in patients were lower than in volunteers (1.2 ± 0.38 versus 3.0 ± 1.0; P < 0.05). Conclusion The rTSE sequence generates nonsubtractive, flow‐independent, peripheral MR angiograms with better arterial–venous contrast and vessel sharpness in normal volunteers than a conventional TSE sequence. J. Magn. Reson. Imaging 2014;39:1468–1476 . © 2013 Wiley Periodicals, Inc .