Maria Boviatsi-Gavra, Presenter: Nothing to Disclose

James Patrick Connelly MBBS, Abstract Co-Author: Nothing to Disclose

Marguerite Du Preez, Abstract Co-Author: Nothing to Disclose

Celia O'Meara, Abstract Co-Author: Nothing to Disclose

Jamshed Bomanji, Abstract Co-Author: Nothing to Disclose

Leon Jonathan Menezes FRCR, Abstract Co-Author: Stockholder, General Electric Company Research Grant, Advanced Accelerator Applications SA Research Grant, Eli Lilly and Company

 Congenital hyperinsulinism (CHI) is the most common cause of hypoglycaemia in infants. There are two histological types diffuse and focal which require different management. The limited resection of focal lesions is potentially curative. Thus the pre-operative differentiation is critical. The purpose of this study was to evaluate the use of PET/MR with 18F fluoro-L-DOPA to distinguish focal from diffuse CHI compared to PET/CT. 

Twelve patients (2 boys, 10 girls; median age 6.7 months) with CHI underwent imaging on GE DVCT 64–slice PET/CT and PET/MR imaging on 3 Tesla Siemens Biograph mMR. Dynamic PET scans were acquired 20 and 40 min after injection of 4MBq/kg 18F-DOPA, with contrast enhanced CT, followed by PET/MRI with T2 weighted, diffusion weighted and T1-VIBE post gadolinium, 90 min post DOPA injection. Each acquisition was assessed by two independent observers with visual interpretation and confidence ratings. Standardized Uptake Values (SUVmax) were measured in the head, body and tail of pancreas at 40 minutes with PET/CT and at 90 minutes with PET/MR. Patients were diagnosed with focal versus diffuse CHI on the basis of visual analysis and a target to background ratio (TBR) of 1.5. 

All images were diagnostic/evaluable. Two patients had focal CHI. Ten patients had diffuse CHI. In four cases (1 focal and three diffuse) there was a greater confidence in identifying the different types of CHI in PET/MR than in PET/CT. There was no significant difference between TBR ratios in PET/CT and PET/MR in distinguishing the different forms of CHI           (p value1.0, t-Test). The results were concordant in 12/12 patients with both methods. The two patients with focal uptake underwent surgery with histopathological confirmation.

18F-DOPA PET/MR is not inferior to PET/CT in the preoperative differentiation of focal from diffuse CHI. In addition, PET/ MR provides better soft tissue contrast and has reduced radiation exposure which is particularly beneficial in the paediatric population. These results suggest that 18F-DOPA PET/MR should be considered in all infants with CHI.

Simultaneous 18F-DOPA PET/MR has advantages over PET/CT to diagnose the focal versus the diffuse form of congenital hyperinsulinism of infancy.  

Boviatsi-Gavra, M, Connelly, J, Du Preez, M, O'Meara, C, Bomanji, J, Menezes, L, Simultaneous 18F-DOPA PET/MRI in Children with Congenital Hyperinsulinism: Advantages over PET/CT.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017936.html