Figure 3. Cross-sectional imaging in gastrointestinal NET. Due to their hypervascular nature, NET primary lesions and metastases can be enhancing in early arterial phase. In case (A) diffuse hypervascular liver metastases of a small intestinal NET are visible. Not all NET (metastases) are hypervascular, as shown in case (B) with a single non-enhancing liver metastasis of small intestinal NET during arterial phase (arrow). The added value of including an early arterial phase after contrast injection (C) op top of venous phase imaging (D) is illustrated within a patient with a small intestinal NET, where visibility of a segment 3 NET metastasis is improved during arterial scan. MRI, particularly diffusion weighted imaging (DWI), can improve the detection rate of small liver NET metastases (E).