Related Experiment Video
Updated: May 12, 2026
Bioluminescence and Near-infrared Imaging of Optic Neuritis and Brain Inflammation in the EAE Model of Multiple Sclerosis in Mice
Published on: March 1, 2017
The T1-dark-rim: A novel imaging sign for detecting smoldering inflammation in multiple sclerosis
Pablo Naval-Baudin1, Albert Pons-Escoda1, Albert Castillo-Pinar2
1Radiology Department, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Carrer de Feixa Llarga SN, 08907 Barcelona, Spain; Institut de Diagnòstic Per La Imatge (IDI), L'Hospitalet de Llobregat, Centre Bellvige, Carrer de Feixa Llarga SN, 08907 Barcelona, Spain; Diagnostic Imaging and Nuclear Medicine Research Group, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08907 Barcelona, Spain; Departament de Ciències Clíniques, Facultat de Medicina I Ciències de La Salut, Universitat de Barcelona (UB), Carrer de Casanova 143, 08036 Barcelona, Spain.
Purpose:
Paramagnetic rim lesions (PRLs), usually identified in susceptibility-weighted imaging (SWI), are a promising prognostic biomarker of disability progression in multiple sclerosis (MS). However, SWI is not routinely performed in clinical practice. The objective of this study is to define a novel imaging sign, the T1-dark rim, identifiable in a standard 3DT1 gradient-echo inversion-recovery sequence, such as 3D T1 turbo field echo (3DT1FE) and explore its performance as a SWI surrogate to define PRLs.
Methods:
This observational cross-sectional study analyzed MS patients who underwent 3T magnetic resonance imaging (MRI) including 3DT1TFE and SWI. Rim lesions were evaluated in 3DT1TFE, processed SWI, and SWI phase and categorized as true positive, false positive, or false negative based on the value of the T1-dark rim in predicting SWI phase PRLs. Sensitivity and positive predictive values of the T1-dark rim for detecting PRLs were calculated.
Results:
Overall, 80 rim lesions were identified in 63 patients (60 in the SWI phase and 78 in 3DT1TFE; 58 true positives, 20 false positives, and two false negatives). The T1-dark rim demonstrated 97% sensitivity and 74% positive predictive value for detecting PRLs. More PRLs were detected in the SWI phase than in processed SWI (60 and 57, respectively).
Conclusion:
The T1-dark rim sign is a promising and accessible novel imaging marker to detect PRLs whose high sensitivity may enable earlier detection of chronic active lesions to guide MS treatment escalation. The relevance of T1-dark rim lesions that are negative on SWI opens up a new field for analysis.
Insights
The T1-dark rim sign, identifiable on standard MRI scans, effectively detects paramagnetic rim lesions (PRLs) in multiple sclerosis (MS). This accessible marker shows high sensitivity for identifying chronic active lesions, aiding in MS treatment decisions.
Area of Science:
- Neuroimaging
- Radiology
- Neurology
Background:
- Paramagnetic rim lesions (PRLs) are key prognostic biomarkers for disability progression in multiple sclerosis (MS).
- Susceptibility-weighted imaging (SWI) is crucial for identifying PRLs but is not routinely used in clinical practice.
- There is a need for accessible imaging markers that can surrogate SWI for PRL detection.
Purpose of the Study:
- To define a novel imaging sign, the T1-dark rim, visible on standard 3D T1 gradient-echo inversion-recovery sequences.
- To evaluate the T1-dark rim's performance as a surrogate for SWI in identifying PRLs.
- To assess the T1-dark rim's potential as an accessible biomarker for MS.
Main Methods:
- An observational, cross-sectional study involving MS patients who underwent 3T MRI, including 3DT1 turbo field echo (3DT1FE) and SWI.
- Rim lesions were evaluated on 3DT1FE and SWI (processed and phase images).
- The T1-dark rim's accuracy in predicting SWI-defined PRLs was assessed by calculating sensitivity and positive predictive values.
Main Results:
- A total of 80 rim lesions were identified in 63 patients (78 on 3DT1FE, 60 on SWI phase).
- The T1-dark rim sign demonstrated high sensitivity (97%) and a positive predictive value of 74% for detecting PRLs.
- More PRLs were detected using SWI phase imaging compared to processed SWI.
Conclusions:
- The T1-dark rim is a promising, accessible imaging marker for detecting PRLs in MS.
- Its high sensitivity may facilitate earlier identification of chronic active lesions, guiding MS treatment escalation.
- T1-dark rim lesions not detected on SWI warrant further investigation for their clinical significance in MS.
