Table 2:
Radiographic findings in IgG4-related disease
| Organ system | Typical findings |
|---|---|
| Pancreas58 | CT: focal (more common) or diffuse pancreatic enlargement with delayed enhancement and a low-density “halo”; pancreatic atrophy is uncommon Cholangiography: diffuse irregular narrowing of the pancreatic duct |
| Salivary gland | CT: swelling is often bilateral and preferentially involves the submandibular glands US:59 multiple hypoechoic lesions in affected glands MRI:60 homogenous enhancement in hypointense or isointense T2-weighted imaging |
| Orbits61 | CT: involvement of any surrounding structures including lacrimal glands, nerves, extraocular muscles and maxillary and frontal bony structures |
| Lungs9 | CT: four major categories of findings (solid nodular masses, localized ground glass opacities, diffuse ground glass opacities associated with honeycomb lung and bronchovascular thickening); mediastinal lymphadenopathy is common Diffuse tracheal inflammation and subglottic stenoses may also be seen |
| Arterial system62 | CT: adventitial sclerosing inflammation characterized by diffuse wall thickening and late-phase enhancement |
| Retroperitoneum63 | CT: perivascular fibrosis concentrates around the aorta, iliac vessels and vena cava. Occasionally, fibrotic disease will dominate perirectal and retrovesicular spaces. Associated lymphadenopathy and aortitis is common. |
| Kidneys64 | CT: abnormalities noted in 70% of patients with renal disease include bilateral diffuse enlargement, solitary nodules and atrophy MRI: low-density lesions with T2-weighting hypointensity, with progressive enhancement pattern |
| Biliary tree | Cholangiography: stricturing disease is difficult to differentiate from other causes of sclerosing cholangitis. Common bile duct thickness of > 2.5 mm and continuous strictures can be suggestive of IgG4-RD rather than PSC;65 4 patterns of stricturing disease have been described, but the clinical relevance of the different types is not obvious66 Cholangioscopy: direct mucosal visualization may give diagnostic clues, although this requires thorough validation67 |
| Meninges and brain8 | CT: diffuse dural thickening or perineural masses as large as 3 cm in diameter; pituitary lesions require MRI |
Note: CT = computed tomography, IgG4-RD = immunoglobulin G4–related disease, MRI = magnetic resonance imaging, PSC = primary sclerosing cholangitis, US = ultrasonography.