Seven patients who had functioning or non-functioning endocrine pancre
atic tumours were investigated by magnetic resonance imaging. Combinat
ions of fat suppressed T-1 weighted spin echo and gradient recalled ec
ho (n = 7), T-2 weighted spin echo(n = 3) and gadolinium diethylamine
triamine pentaacetic acid (Gd-DTPA) enhanced fat suppressed T-1 images
were acquired. Magnetic resonance imaging detected five of seven tumo
urs prospectively (three of which were smaller than 10 mm) and a furth
er 10 mm tumour retrospectively. Tumours were low signal on T-1 weight
ed images and showed enhancement after Gd-DTPA. On T-2 weighted images
one tumour was hyperintense, and two were isointense with normal panc
reas. Computed tomography, transabdominal ultrasound and angiography w
ere performed in six patients but detected only one tumour each. Intra
operative palpation and ultrasound detected all tumours. If pre-operat
ive imaging is required magnetic resonance imaging is the technique of
choice to detect small endocrine pancreatic rumours.