Table 3

Imaging characteristics of early PML-IRIS

Number of patients (%)
Mass effect10 (38.5)*
Signs of oedema7 (26.9)*
Perivascular T2 lesions9 (34.6)*
Contrast-enhancing lesions24 (92.3)*
Localisation of contrast enhancement
  In the centre of PML lesions4 (16.7)†
  In the border of PML lesions23 (95.8)†
  Outside of PML lesions‡3 (12.5)†
  Punctuate perivascular enhancement§8 (33.3)†
Pattern of contrast enhancement
  Punctate11 (45.8)†
  Homogeneous0 (0)†
  Patchy17 (70.8)†
Signs of meningeal inflammation0 (0)*
  • *Percentage of all 26 patients.

  • †Percentage of the 24 patients with contrast-enhancing lesions.

  • ‡Without a distinct perivascular distribution.

  • §Perivascular enhancement pattern was only considered for enhancing lesions with a perivascular enhancement pattern outside of PML lesions and these lesions were per definition punctuate.

  • ¶The punctuate enhancing lesions with a perivascular distribution pattern are not included in these numbers.

  • IRIS, immune reconstitution inflammatory syndrome; PML, progressive multifocal leukoencephalopathy.