Hybrid imaging of the bowel using PET/MR enterography: Feasibility and first results

Abstract

Purpose: To implement a protocol for PET/MR enterography for a multimodal assessment of intestinal pathologies.

Materials and methods: 19 patients with bowel malignancies, Crohn's disease or fever of unknown origin (male: n=14, female: n=5, age: 57±13years) underwent PET/MR enterography with either [(18)F]FDG (n=10) or [(68)Ga]-DOTATOC (n=9) using an integrated scanner. For small bowel distension a contrast solution (1500 cm(3) of mannitol and locust bean gum) was ingested. The following sequences were acquired: (a) coronal TrueFISP; (b) coronal T2w HASTE; (c) coronal dynamic T1w VIBE; (d) axial and coronal T1w FLASH post gadolinium. All datasets were reviewed by two readers with regard to co-registration of anatomical structures based on a 3-point ordinal scale as well as overall image quality using a 4-point ordinal scale. Furthermore, visualization of intestinal and extra-intestinal pathologies was assessed.

Results: PET/MR enterography was well tolerated by all patients. High overall MR image quality was achieved (mean score: 3.2±0.6) with good co-registration of PET and MRI (mean scores: 2.6 to 3.0). PET/MR enterography allowed for an excellent visualization of both intestinal as well as extra-intestinal pathologies.

Conclusion: PET/MR enterography is technically feasible and offers good co-registration of bowel structures. This novel method enables a multimodal assessment of bowel lesions in malignant and inflammatory disease.

Keywords: Large bowel; PET/MR; Small bowel.