Abstract: A nuclear medicine imaging system provides three-axis linear and rotary detector motion. The imaging system includes an overhead gantry, which includes a carriage supported above the object and movable in translation along a first horizontal axis. Support arms are suspended downward from the carriage and are movable along a second horizontal axis perpendicular to the first horizontal axis. A detector is coupled to a lower end of each support arm. Each support arm is retractably extendible along a substantially vertical axis, and each detector is pivotable about a horizontal axis parallel to the first horizontal axis. Each support arm cooperates with the carriage to enable the corresponding detector to be positioned at multiple angular positions about a longitudinal axis corresponding to multiple projection angles by using combinations of independent linear movements of the detectors along any of three perpendicular axes.