High contrast cartilaginous endplate imaging in spine using three dimensional dual-inversion recovery prepared...

To investigate the feasibility and application of a novel imaging technique, a three-dimensional dual adiabatic inversion recovery prepared ultrashort echo time (3D DIR-UTE) sequence, for high contrast assessment of cartilaginous endplate (CEP) imaging with head-to-head comparisons between other UTE imaging techniques.

The DIR-UTE sequence employs two narrow-band adiabatic full passage (AFP) pulses to suppress signals from long T₂ water (e.g., nucleus pulposus (NP)) and bone marrow fat (BMF) independently, followed by multispoke UTE acquisition to detect signals from the CEP with short T₂ relaxation times. The DIR-UTE sequence, in addition to three other UTE sequences namely, an IR-prepared and fat-saturated UTE (IR-FS-UTE), a T₁-weighted and fat-saturated UTE sequence (T_1w-FS-UTE), and a fat-saturated UTE (FS-UTE) was used for MR imaging on a 3 T scanner to image six asymptomatic volunteers, six patients with low back pain, as well as a human cadaveric specimen. The contrast-to-noise ratio of the CEP relative to the adjacent structures-specifically the NP and BMF-was then compared from the acquired images across the different UTE sequences.

For asymptomatic volunteers, the DIR-UTE sequence showed significantly higher contrast-to-noise ratio values between the CEP and BMF (CNR_CEP-BMF) (19.9 ± 3.0) and between the CEP and NP (CNR_CEP-NP) (23.1 ± 1.7) compared to IR-FS-UTE (CNR_CEP-BMF: 17.3 ± 1.2 and CNR_CEP-NP: 19.1 ± 1.8), T_1w-FS-UTE (CNR_CEP-BMF: 9.0 ± 2.7 and CNR_CEP-NP: 10.4 ± 3.5), and FS-UTE (CNR_CEP-BMF: 7.7 ± 2.2 and CNR_CEP-NP: 5.8 ± 2.4) for asymptomatic volunteers (all P-values < 0.001). For the spine sample and patients with low back pain, the DIR-UTE technique detected abnormalities such as irregularities and focal defects in the CEP regions.

The 3D DIR-UTE sequence is able to provide high-contrast volumetric CEP imaging for human spines on a clinical 3 T scanner.