An image display apparatus according to the invention comprises reading section (11a) which reads in an image data set of a subject acquired by a medical imaging apparatus (2) from a data recording device (13) which stores the image data set; input sections (16, 17) which input a desired object organ to the read-in image data set; object organ extracting section (11b) which extracts the inputted object organ; reference position setting section (11h) which sets a reference position for producing an unfolded image in the circumferential direction of the bore of the extracted object organ; calculating device (11e) which calculates pixel information in the circumferential direction of the bore of the object organ from the set reference position; and image display section (15) which displays the calculated pixel information in the circumferential direction of the bore of the object organ.