Contract and advance cancellation of MRI time slots for stroke patients

This paper addresses the design of contract-based solutions for MRI (Magnetic resonance imaging) examinations for stroke patients treated in a neurovascular department. A contract-based solution is characterized by: contracted time slots (CTS) reserved by the imaging department for the neurovascular department, advance cancellation of contracted time slots, and requests for regular time slots (RTS). The problem of CTS cancellation and RTS assignment is formulated as an average cost Markov Decision Process in order to minimize costs incurred by patient waiting times, unused CTS and CTS cancellation. Structural properties of the optimal control policies are established. Numerical results show that advance CTS cancellation significantly reduces the ratio of unused CTS with slight increase of patient waiting time.