A COMBINED ANALYSIS AND MAGNETIC-RESONANCE-IMAGING TECHNIQUE FOR COMPUTERIZED AUTOMATIC-MEASUREMENT OF CARTILAGE THICKNESS IN THE DISTAL INTERPHALANGEAL JOINT

It is well known that magnetic resonance imaging (MRI) contrast can be controlled, albeit sometimes at the expense of image resolution and s ignal-to-noise ratio, and most studies of articular joints have used a single MRI protocol, which is optimised for subjective image analysis . Inevitably that single protocol frequently compromises the detection of one or another of the boundaries between which any measurement mus t be made. This paper describes an alternative approach in which the c riteria for computerised edge detection necessary for fully automated measurement of cartilage thickness are used to define the MRI acquisit ion parameters. This necessitates the combined use of two MRI sequence s, one optimised for the cartilage-bone boundary, and the other for ca rtilage-synovial fluid. This provides a highly effective combination a nd its efficacy is demonstrated for the distal interphalangeal joint o f a range of asymptomatic adults.