The Parallel Analysis of Phase Sensitive Inversion Recovery (PSIR) and Double Inversion Recovery (DIR) Images Significantly Improves the Detection of Cortical Lesions in Multiple Sclerosis (MS) since Clinical Onset

Abstract

BackgroundDouble inversion recovery (DIR) detects only a minority (<20%) of cortical lesions (CL) in multiple sclerosis (MS). Phase-sensitive inversion recovery (PSIR) was suggested to be substantially superior to DIR in the detection of cortical lesions (CL). These two sequences might be complementary.ObjectivesTo analyze CL frequency and type in MS patients having different disease duration and disability, including patients at clinical onset, and to discern more correctly the artifacts, by combining DIR and PSIR images.Patients and Methods40 patients were enrolled in the study: 10 clinically isolated syndrome/early relapsing remitting MS (CIS/eRRMS), 24 relapsing remitting MS (RRMS), 6 secondary progressive MS (SPMS). DIR and PSIR images were jointly used to classify lesions as purely intracortical (IC), leukocortical (LC) and juxtacortical (JC).ResultsPSIR disclosed CL in 100% of the patients and was capable of identifying more than four times lesions (455.5%, p<0.00001), especially IC (mean numbers: 36.5 in CIS/eRRMS, 45.0 in RRMS and 52.3 in SPMS) and LC (mean numbers: 10.9 in CIS/eRRMS, 20.1 in RRMS and 25.3 in SPMS), compared to DIR (p<0.00001). CL number was significantly higher in SPMS compared to RRMS (p<0.0001). Artifacts were more accurately identified by comparing the two sequences.ConclusionsOur study confirms the higher ability of PSIR in disclosing and classifying CL. The presence of CL in all CIS patients further points out the relevance of cortical pathology in MS. Whether the parallel analysis of DIR and PSIR images may be useful for diagnostic purposes, especially when a diagnosis of MS is suspected but not confirmed by routine MRI, needs to be evaluated in larger patient series. The analysis of the cortex by DIR and PSIR may also allow a better stratification of the patients for prognostic and counseling purposes, as well as for their inclusion in clinical studies.

Detection of Leukocortical Lesions in Multiple Sclerosis and Their Association with Physical and Cognitive Impairment: A Comparison of Conventional and Synthetic Phase-Sensitive Inversion Recovery MRI

“…Combining different sequences, as performed for the criterion standard, was subjectively the preferred approach by the raters in the current study to accurately delineate cortical involvement, which supports previously proposed multimodal reading protocol approaches. 4,[29][30][31] Synthetic MR imaging has previously been shown to provide proton-density-, T1-, and T2-weightings in diagnostic quality (as illustrated in the On-line Figure) [13][14][15] as well as automatic volumetrics, 13 with a single acquisition. The image quality of synthetic FLAIR images has, however, been shown to be hampered by artifacts.…”

The Role of Advanced Magnetic Resonance Imaging Techniques in Multiple Sclerosis Clinical Trials

“…Three-dimensional (3D) double inversion recovery (DIR) allows for suppression of the CSF and WM in FLAIR, detects 18% of CLs versus postmortem verification, and is 1.6-fold superior to 3D-FLAIR [22]. Phase-sensitive inversion recovery may be useful concomitantly with DIR to further improve CL contrast [23]. GM juxtacortical lesions have been identified with phase difference-enhanced imaging [24], and 3D magnetization-prepared rapid acquisition with gradient echo can also help classify CL type [25].…”

“…Magnetic resonance spectroscopy (MRS) provides 3D quantitative information based on the properties of different nuclei (e.g., 1 H, 31 P, 13 C, 23 Na) and their respective relaxation times. Proton ( 1 H) MRS, in particular, has been utilized for characterizing MS pathology since the early 1990s and can typically be acquired in < 20 min [114].…”

MRI in the assessment and monitoring of multiple sclerosis: an update on best practice

“…107 Additional sequences such as double inversion recovery or PSIR can help with the detection of gray matter lesions. 108,109 Yet the sensitivity is not ideal and therefore caution is still required before the presence of gray matter lesions can be reliably assessed and added to the diagnostic guidelines.…”