Multispectral 3D phase-encoded turbo spin-echo for imaging near metal: Limitations and possibilities demonstrated by simulations and phantom experiments

Jetse S. van Gorp*, Razmara Nizak, Job G. Bouwman, Daniël B.F. Saris, Peter R. Seevinck

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)

Abstract

To see improvements in the imaging performance near biomaterial implants we assessed a multispectral fully phase-encoded turbo spin-echo (ms3D-PE-TSE) sequence for artifact reduction capabilities and scan time efficiency in simulation and phantom experiments. For this purpose, ms3D-PE-TSE and ms3D-TSE sequences were implemented to obtain multispectral images (± 20 kHz) of a cobalt-chromium (CoCr) knee implant embedded in agarose. In addition, a knee implant computer model and the acquired ms3D-PE-TSE images were used to investigate the possibilities for scan time acceleration using field-of-view (FOV) reduction for off-resonance frequency bins and compressed sensing reconstructions of undersampled data. Both acceleration methods were combined to acquire a + 10 kHz frequency bin in a second experiment. The obtained ms3D-PE-TSE images showed no susceptibility related artifacts, while ms3D-TSE images suffered from hyper-intensity artifacts. The limitations of ms3D-TSE were apparent in the far off-resonance regions (±[10–20] kHz) located close to the implant. The scan time calculations showed that ms3D-PE-TSE can be applied in a clinically relevant timeframe (~ 12 min), when omitting the three central frequency bins. The feasibility of CS acceleration for ms3D-PE-TSE was demonstrated using retrospective reconstructions before combining CS and rFOV imaging to decrease the scan time for the + 10 kHz frequency bin from ~ 10.9 min to ~ 3.5 min, while also increasing the spatial resolution fourfold. The temporally resolved signal of ms3D-PE-TSE proved to be useful to decrease the intensity ripples after sum-of-squares reconstructions and increase the signal-to-noise ratio. The presented results suggest that the scan time limitations of ms3D-PE-TSE can be sufficiently addressed when focusing on signal acquisitions in the direct vicinity of metal implants. Because these regions cannot be measured with existing multispectral methods, the presented ms3D-PE-TSE method may enable the detection of inflammation or (pseudo-)tumors in locations close to the implant.

Original languageEnglish
Pages (from-to)31-43
Number of pages13
JournalMagnetic resonance imaging
Volume39
DOIs
Publication statusPublished - 1 Jun 2017
Externally publishedYes

Keywords

  • Field inhomogeneities
  • Fully phase-encoded MRI
  • Implants
  • Multispectral 3D phase-encoded turbo spin-echo
  • Near-metal imaging
  • Susceptibility

Fingerprint Dive into the research topics of 'Multispectral 3D phase-encoded turbo spin-echo for imaging near metal: Limitations and possibilities demonstrated by simulations and phantom experiments'. Together they form a unique fingerprint.

  • Cite this