The signal intensity variation of multiple sclerosis (MS) lesions on magnetic resonance imaging (MRI) as a potential biomarker for patients’ disability: A feasibility study

Abstract

IntroductionAlthough many lesion-based MRI biomarkers in multiple sclerosis (MS) patients were investigated, none of the previous studies dealt with the signal intensity variations (SIVs) of MS lesions. In this study, the SIVs of MS lesions on direct myelin imaging and standard clinical sequences as possible MRI biomarkers for disability in MS patients were assessed.MethodsTwenty seven MS patients were included in this prospective study. IR-UTE, FLAIR, and MPRAGE sequences were employed on a 3T scanner. Regions of interest (ROIs) were manually drawn within the MS lesions, and the cerebrospinal fluid (CSF) and signal intensity ratios (SIR) were calculated from the derived values. Variations coefficients were determined from the standard deviations (Coeff 1) and the absolute differences (Coeff 2) of the SIRs. Disability grade was assessed by the expanded disability status scale (EDSS). Cortical/gray matter, subcortical, infratentorial, and spinal lesions were excluded.ResultsThe mean diameter of the lesions was 7.8 ± 1.97 mm, while the mean EDSS score was 4.5 ± 1.73. We found moderate correlations between the EDSS and Coeff 1 and 2 on IR-UTE and MPRAGE images. Accordingly, Pearson’s correlations on IR-UTE were R = 0.51 (p = 0.007) and R = 0.49 (p = 0.01) for Coeff 1 and 2, respectively. For MPRAGE, Pearson’s correlations were R = 0.5 (p = 0.008) and R = 0.48 (p = 0.012) for Coeff 1 and 2, respectively. For FLAIR, only poor correlations could be found.ConclusionThe SIVs of MS lesions on IR-UTE and MPRAGE images, assessed by Coeff 1 and 2, could be used as novel potential MRI biomarkers for patients’ disability.

Retrospectively gated ultrashort‐echo‐time MRI T1 mapping reveals compromised pulmonary microvascular NO‐dependent function in a murine model of acute lung injury

“…To avoid the lengthy acquisition time inherent to standard radial sampling in 3D UTE, an advantage can be taken of novel sampling strategies based on cone or stack-of-stars trajectories, as shown previously. [38][39][40]75 The average T 1 of lungs recorded in this study falls well within the expected range at B 0 = 9.4 T, at T 1 = 1101 ± 62 ms, and T 1 = 1078 ± 38 ms using nongated and motion-resolved images, respectively. Tibiletti et al 22 reported an average T 1 = 1500 ± 34 ms and T 1 = 710 ± 14 ms at B 0 = 7 T using global and selective inversion recovery, respectively.…”

“…By extending the imaging to 3D, it would be possible to further reduce the echo time at the expense of prolonged acquisition time. To avoid the lengthy acquisition time inherent to standard radial sampling in 3D UTE, an advantage can be taken of novel sampling strategies based on cone or stack‐of‐stars trajectories, as shown previously 38‐40,75 . The average T 1 of lungs recorded in this study falls well within the expected range at B 0 = 9.4 T, at T 1 = 1101 ± 62 ms, and T 1 = 1078 ± 38 ms using nongated and motion‐resolved images, respectively.…”

“…TyGA sampling suppresses eddy‐current‐induced image artifacts that are caused by rapid switching of gradients with GA sampling, and additionally enables reconstruction of data at different spatial and temporal resolutions from a single, continuously acquired dataset. It is worth noting that the concept of tyGA could be readily extended to 3D imaging, which together with recent advances in nonuniform k ‐space sampling could constitute a time‐efficient and powerful tool for various applications of UTE imaging 38‐40 …”

“…It is worth noting that the concept of tyGA could be readily extended to 3D imaging, which together with recent advances in nonuniform k-space sampling could constitute a time-efficient and powerful tool for various applications of UTE imaging. [38][39][40] The feasibility of tyGA UTE for imaging lung function in mice was first demonstrated by Balasch et al 41 with examples of anatomical, ventilation, and contrast-enhanced imaging in healthy animals. From a practical perspective, these motion-resolved UTE images could be used to assess molecular parameters of the lungs via changes in tissue relaxation caused by an injection of a contrast agent.…”

Association of vulnerable plaques with white matter hyperintensities on high-resolution magnetic resonance imaging

“…With the rapid advancement of computer technology in recent years, new possibilities in MRI have emerged, including the accurate segmentation of the gray and white matter of the brain. These novel approaches hold tremendous promise for advancing the field of neuroscience and have led to numerous landmark findings ( 21 - 23 ). Conventional imaging methods have limitations in resolution, which makes it difficult to image small blood vessels in the brain.…”