One-shot dual imaging: simultaneous visualization of bone and nerve structures using modified DIXON and fast field...

Simultaneous evaluation of osseous and neural structures is important in assessing lumbar spine pathologies. However, conventional magnetic resonance imaging (MRI) sequences cannot depict both structures simultaneously, and multiple sequences may prolong scanning time and cause spatial misregistration. This preliminary feasibility study investigated whether modified Dixon (mDIXON, Philips Healthcare)-assisted fast field echo resembling computed tomography using restricted echo-spacing (FRACTURE, Philips Healthcare) enabled simultaneous depiction of both structures from a single acquisition.

In this single-center prospective study, healthy volunteers underwent lumbar spine MRI using a 1.5-T MRI system. Bone (in-phase) and nerve (water) images obtained using mDIXON-assisted FRACTURE (3D-mDIXON) were compared with conventional FRACTURE and 3D-FFE-ProSet (3D-ProSet), respectively. Image performance was evaluated using the contrast-to-noise ratio (CNR) and visual assessment. The Wilcoxon signed-rank test was used to compare CNR and visual assessment scores. Interobserver agreement was assessed according to the intraclass correlation coefficient (ICC[A,2]).

Twenty healthy volunteers (mean age, 48.2 ± 9.6 years) were included. For bone evaluation, the CNR was significantly higher with 3D-mDIXON (in-phase) than with FRACTURE (p < 0.01). For nerve evaluation, CNR did not significantly differ between 3D-mDIXON (water) and 3D-ProSet. However, the overall preference score (p < 0.01) and motion artifact score (p < 0.01) were significantly higher for 3D-mDIXON than for 3D-ProSet.

The 3D-mDIXON technique enables the simultaneous depiction of both structures from a single acquisition while maintaining adequate image quality. This approach may improve imaging efficiency and facilitate assessment of their spatial relationship.