A magnetic resonance imaging system (100) for detecting a gas bubble (124, 148, 304, 306, 404, 406) within an imaging volume (108), the magnetic resonance imaging system comprising: a magnet (102) adapted for generating a magnetic field for orientating the magnetic spins of nuclei of a subject (104) located within the imaging volume； a radio frequency system (110, 112) adapted for acquiring magnetic resonance data (160, 164), wherein the radio frequency system comprises a radio frequency transceiver (112) and a radio frequency coil (110)； a magnetic field gradient coil (114) adapted for spatial encoding of the magnetic spins of nuclei within the imaging volume； a magnetic field gradient coil power supply (116) adapted for supplying current to the magnetic field gradient coil； and a computer system (132) adapted for constructing images from the magnetic resonance imaging data and for controlling the operation of the magnetic resonance imaging system, wherein the computer system is adapted for detecting the gas bubble within the imaging volume using a magnetic resonance image (162, 166, 300, 400) constructed from the magnetic resonance imaging data.
