MRI and ultrasonography are useful tools for a non-invasive diagnosis of IgG4-related disease

We read with much interest the 2019 classification criteria for IgG4-related disease by the American College of Rheumatology and the European League Against Rheumatism.1 This new classification driven by scientific evidence and research provides a substantial amount of new information, which will considerably improve the identification and management of patients with IgG4-related disease. Despite the fact that radiology is integrated into the diagnostic criteria, only CT and/or positron emission tomography-CT are mentioned. We humbly suggest that the use of ultrasonography and/or MRI …