Planning and advance cancellation of MRI examinations of stroke patients

Stroke patients need quick diagnosis which relies on a number of examinations by imaging techniques. These equipments are usually expensive and heavily used, which results in long waiting time. Reducing waiting time for the examinations is crucial for stroke patients. For this purpose, we proposed a new reservation process of MRI time slots (Magnetic Resonance Imaging) between the neurovascular department and the imaging department. The neurovascular department reserves a certain number of contracted time slots (CTS) in advance to ensure quick diagnosis of the stroke patients. In addition to CTS, patients can use regular reservations for the MRI examination. Our previous studies addressed the problem of determining the contract, i.e. the distribution of CTS and the control policy to assign patients for CTS or regular reservations. This paper further improves the management of MRI examinations through advance cancellation of CTS. An average cost Markov Decision Process (MDP) is proposed to deal with this problem. Extensive numerical experiments show that the proposed control policy for advance cancellation greatly improves the performance of CTS. Numerical results also show the impact of different data on the advance cancellation control policy.