Type 1 Autoimmune Pancreatitis:
18F-FDG-PET/CT imaging

Fig.1 and 2

Fig.3

Fig.4

Enlarged pancreas, with loss of lobulated margins and a vague patchy opacity in the proximal anterior body region (white arrow, Fig.1). Concomitant cyst adjacent to the tail (arrowhead, Fig.2). The cyst will progressively disappear over time.

Coronal CT in Fig.3. Circumferential thickening of the common bile duct (up to 0.5 cm), extended for approximately 2.5 cm, with wall enhancement (white arrow), associated to intrahepatic bile ducts dilation (curved arrows).

Coronal CT in Fig.4. Multiple rounded solid parenchymal hypodensities in both kidneys, randomly distributed (arrowheads). No hydronephrosis bilaterally.

Fig.5 – ERPC



Fig.6 and 7

Fig.8

Fig.5: Small duct of Wirsung, characterized by diffusely irregular margins (white arrows) and a tiny incomplete focal stenosis in the neck (arrowhead).
Unsuccessful selective cannulation of the CBD.

Diffuse heterogeneous increased radiotracer uptake throughout the entire pancreas (white arrows, Fig. 6), slightly more marked in the region of the head

Diffuse heterogeneous increased radiotracer uptake throughout the renal parenchyma bilaterally (arrowheads, Fig.7 and 8).


Description:

Type I autoimmune pancreatitis (AIP) is the main manifestation of systemic IgG4 related disease (IgG4-RD), a fibro-inflammatory condition which can affect nearly every organ. In up to 35% of patients there is also involvement of kidneys (frequently bilateral), as round/wedge-shape cortical nodules, peripheral cortical or masslike lesions. Morphologic imaging, mainly CT and MRI, plays a crucial role in diagnosis of IgG4-RD organs involvement and for follow-up, mainly after steroid therapy. 18F-FDG-PET/CT imaging is an additional useful tool for mapping involved organs, guiding biopsy and monitoring treatment response.

 

This Case was kindly provided by:

Dr. Pietro Andrea Bonaffini (fellow)
McGill University Health Center (MUHC)
Department of Radiology
1001 Decarie Blvd, Montreal, QC H4A 3J1 – Canada
Contact

 

Dr. Caroline Reinhold (Professor, Associate Chair of Research)
McGill University Health Center (MUHC)
Department of Radiology
1001 Decarie Blvd, Montreal, QC H4A 3J1 – Canada