Canine insulinomas and their presumed metastases are most conspicuous in the late arterial phase in a triple arterial phase CT protocol

Skarbek, Adrianna; Fouriez-Lablée, Virginie; Dirrig, Helen; Llabres-Diaz, Francisco

Abstract

Avid arterial enhancement is the commonly described characteristic of canine insulinomas in contrast-enhanced computed tomography (CECT). However, this finding is also reported as inconsistent.
The main aim of this study was to investigate in detail the contrast enhancement (CE) pattern of canine insulinomas and presumed metastases in three consecutive (early, mid and late) arterial phases (EAP, MAP & LAP).
This single centre retrospective observational study included dogs with a clinical, cytological, or histopathological diagnosis of insulinoma and quadruple-phase CECT. The arterial phases were identified according to published literature. The arterial enhancement of identified lesions was assessed using a visual grading score. Twelve dogs with a total of 17 pancreatic nodules were analysed. Three dogs had multiple pancreatic nodules and nine had solitary lesions. Four insulinomas were histopathologically confirmed.
LAP demonstrated the largest number of nodules reaching the highest enhancement scores (n=13, 76%). All analysed dogs had CT evidence of arterially enhancing nodular lesions in the liver (n=12), seven in the hepatic, splenic or colic lymph nodes and three in the spleen. Three out of five sampled livers and three lymph nodes were metastatic. All sampled spleens were benign.
Avid arterial enhancement was the most dominant feature of canine insulinomas and their metastases in quadruple-phase CECT. The highest enhancement scores were observed primarily in LAP, followed by MAP.
The authors suggest to always include LAP in the standard protocol. MAP could be included to improve the rate of insulinoma detection. Any arterial study including only early arterial images risks missing lesions.

Citation

Skarbek, A., Fouriez-Lablée, V., Dirrig, H., & Llabres-Diaz, F. (2023). Canine insulinomas and their presumed metastases are most conspicuous in the late arterial phase in a triple arterial phase CT protocol. Veterinary Radiology and Ultrasound, https://doi.org/10.1111/vru.13278

• Journal Article Type: Article
• Acceptance Date: Jun 7, 2023
• Online Publication Date: Jul 26, 2023
• Publication Date: Sep 1, 2023
• Deposit Date: Oct 9, 2022
• Publicly Available Date: Sep 27, 2023
• Journal: Veterinary Radiology and Ultrasound
• Print ISSN: 1058-8183
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1111/vru.13278
• Keywords: dog, multiphasic CT, contrast, injection-duration