A 3T Phase-Sensitive Inversion Recovery MRI Sequence Improves Detection of Cervical Spinal Cord Lesions and Shows Active Lesions in Patients with Multiple Sclerosis

Abstract

Background and purpose: Magnetic Resonance Imaging is the modality of choice to detect spinal cord lesions in patients with Multiple Sclerosis (MS). However, this imaging is challenging. New sequences such as phase-sensitive inversion recovery have been developed to improve detection. Our aim was to compare a 3D phase-sensitive inversion recovery and a conventional imaging dataset including postcontrast T2WI and T1WI to detect MS spinal cord lesions.

Materials and methods: This retrospective single-center study included 100 consecutive patients with MS (mean age, 41 years) from January 2015 to June 2016. One senior neuroradiologist and 1 junior radiologist blinded to clinical data checked for new spinal cord lesions, individually analyzing conventional and 3D phase-sensitive inversion recovery datasets separately, placing a 3-week delay between the 2 readings. A consensus reading was done with a third senior neuroradiologist. A Wilcoxon test was used to compare the 2 imaging datasets. Intra- and interobserver agreement was assessed by the κ coefficient.

Results: 3D phase-sensitive inversion recovery detected significantly more lesions than conventional imaging (480 versus 168, P < .001). Eleven patients had no detected lesions on T2WI, whereas 3D phase-sensitive inversion recovery detected at least 1 lesion. All postcontrast T1WI enhancing lesions were also visible on 3D phase-sensitive inversion recovery. The signal-to-noise ratio was significantly higher using 3D phase-sensitive inversion recovery (0.63 versus 0.46, P = .03). Mean reading confidence was significantly higher using 3D phase-sensitive inversion recovery. Inter- and intraobserver agreement was good for both datasets.

Conclusions: Our study showed that 3D phase-sensitive inversion recovery significantly improved detection of cervical spinal cord lesions, including both enhancing and nonenhancing lesions in patients with MS.

Fig 1.

Comparison of the number and distribution of MS lesions detected in the spinal cord using the conventional set (gray) compared with 3D-PSIR (black) imaging.

Fig 2.

Follow-up MR imaging of a 32-year-old woman with relapsing-remitting MS. 3D-PSIR reformatted in the sagittal plane shows 2 conspicuous (black arrows) and 1 less obvious (white arrow) cervical spinal cord lesions seen as hypointense on the phase-corrected real image (A) and hyperintense on the magnitude image (B). The same lesions are all difficult to see on the sagittal T2WI (C).

Fig 3.

Follow-up MR imaging of a 40-year-old woman with secondary-progressive MS. Sagittal T2WI (A) shows no spinal cord lesions. 3D-PSIR reformatted in the sagittal plane (B) demonstrates 2 cervical spinal cord lesions (black arrows). 3D-PSIR reformatted in the axial plane (C) provides accurate localization of the lesions (black arrow).

Fig 4.

Follow-up of a 32-year-old woman with relapsing-remitting MS presenting with acute paresthesia of the upper arm. Sagittal postcontrast T1WI (A) shows an enhancing cervical spinal cord lesion (black arrowhead) corresponding to an active inflammatory lesion. 3D-PSIR reformatted in the sagittal plane shows the same enhancing lesion on the magnitude image (B).