Magnetic resonance imaging with improved thermal performance

A magnetic resonance (MR) imaging apparatus comprises an MR imaging device (10) including a magnet (12) and heat generating components (18, 20, 22, 24). A cooling system (30) cools the heat generating components using chilled water from an air-cool chiller (28). Sensors (TS, VS) are configured to measure thermal parameters of the heat generating components or of the cooling system. An MR controller (40) controls the MR imaging device to execute an MR imaging examination program ("exam card") (42) and to adjust the execution of the MR imaging examination program in response to a thermal parameter measured by the one or more sensors indicating the cooling system has insufficient cooling capacity. The MR controller may also adjust the exam card prior to its execution if the cooling system (30) has insufficient cooling capacity at the current air temperature to dissipate the heat load as estimated by a power dissipation model (80).