Related Experiment Video
Updated: Mar 23, 2026
Imaging CD19+ B Cells in an Experimental Autoimmune Encephalomyelitis Mouse Model using Positron Emission Tomography
Published on: January 20, 2023
Punctate pattern: A promising imaging marker for the diagnosis of natalizumab-associated PML
Jérôme Hodel1, Christine Darchis2, Olivier Outteryck2
1From the University of Lille, CHU Lille (J.H., C.D., O.O., V.D., A.L., J.P.P., P.V., X.L.), Lille, France; Departments of Neuroradiology (J.H., C.D., J.P.P., X.L.), Pathology (V.D.) and Neurology (O.O., A.L., P.V.), Hôpital Roger Salengro, Rue Emile Laine 59037 Lille, France; Department of Radiology (S.V.), Hôpital Saint Philibert, Lille, France; Department of Neuroradiology (J.H.), AP-HP, Hôpitaux Universitaires Henri Mondor, Créteil, France; Faculty of Medicine (J.H.), Université Paris Est Créteil, Créteil, France; and Department of Radiology (M.Z.), Hôpital Saint Joseph, Paris, France. Jerome.hodel@gmail.com.
Objective:
To evaluate the usefulness of the punctate pattern (PP) for the diagnosis and follow-up of patients with progressive multifocal leukoencephalopathy (PML).
Methods:
A cohort of 20 consecutive patients with PML, related to natalizumab (NTZ) (n = 14) or not (n = 6), underwent 3T MRI (147 MRI examinations). MRI was available at presymptomatic (n = 9 patients), symptomatic (n = 15), immune reconstitution inflammatory syndrome (IRIS), and chronic stages (n = 20). A pathologic control group of patients without PML (n = 80), with clinically definitive multiple sclerosis or a clinically isolated syndrome suggestive of CNS demyelination, underwent the same MRI protocol. Number and appearance of punctate lesions were assessed by 3 blinded readers using T2-weighted, fluid-attenuated inversion recovery (FLAIR), and postcontrast T1-weighted images.
Results:
Interobserver agreement was good (κ = 0.79) (0.72-0.87). Of the 20 patients with PML, 18 had PP, including the 14 patients with NTZ-PML; none in the pathologic control group. Of the 9 presymptomatic patients with NTZ-PML, PP was observed in 7 (78% sensitive and 100% specific). Nonenhancing PP on T2-weighted/FLAIR images was detected in 13 patients with PML, exclusively at the presymptomatic or symptomatic stages (including 7 NTZ-PML), whereas enhancing PP occurred in 16 patients with PML, including 13 of the 14 patients with NTZ-PML at the IRIS stage.
Conclusions:
PP is a highly specific feature of PML and may be the first imaging feature at the presymptomatic stage with potential implications in patient care.
Classification Of Evidence:
This study provides Class II evidence that a PP on MRI accurately identifies patients with NTZ-PML.
More Related Videos
10:50Visualizing Impairment of the Endothelial and Glial Barriers of the Neurovascular Unit during Experimental Autoimmune Encephalomyelitis In Vivo
Published on: March 26, 2019
13:28Three-dimensional Confocal Analysis of Microglia/macrophage Markers of Polarization in Experimental Brain Injury
Published on: September 4, 2013