This paper presents a novel air-cushion tactile sensor for Minimally Invasive Surgery that is fully MRI (Magnetic Resonance Imaging) compatible. The proposed sensor is designed to detect tissue abnormalities within soft tissue surfaces. This is achieved by rolling over soft tissue in a virtually frictionless manner due to the design of the sensor in which the sensing element, a sphere, rests on a cushion of air. This design allows for rapid acquisition of tactile and mechanical properties of large areas of soft tissue. Laboratory experiments are carried out to show its feasibility as a tactile sensor for MIS and its behaviour under loading. The outcomes of the experiments illustrate the sensor's capability and potential as a tactile sensor for MIS. These results are discussed and future work is outlined.