Abstract: A three head SPECT camera system has three detector heads (22a, 22b, 22c) disposed at 120.degree. intervals. Two of the detector heads have collimators (40a, 40b) which have a first set of vanes (42a, 42b) extending in a direction parallel to an axis of rotation (26) but which are canted 15.degree. relative to a perpendicular, central axis (32a, 32b) of the respective detector heads. A second set of vanes (46a, 46b) extend perpendicular to the 15.degree. tipped set of vanes to define a rectangular grid. When the second set of vanes is perpendicular to the detector heads, the first detector head is constrained to receive radiation along a first plurality of parallel rays (44a) and the second radiation detector head is constrained to receive radiation along a second plurality of parallel rays (44b). The collimators are mounted to the detector head such that the first and second parallel rays (44a, 44b) are perpendicular to each other. In this manner, a full 180.degree.