A method for imaging a body, including scanning the body so as to generate a
tomographic image thereof, and analyzing the
tomographic image to determine a location of a
region of interest (ROI) within the body. The method includes providing single
photon counting
detector modules, each of the modules being configured to receive photons from a respective direction and to generate a
signal in response thereto. The method further includes
coupling each of the modules to a respective adjustable
mount, adjusting each of the adjustable mounts so that the direction of the module coupled thereto is aligned with respect to the location so as to receive
radiation from the ROI, operating each of the modules to receive the photons from the ROI, and, in response to the
signal generated by each of the modules, generating a single
photon counting image of the ROI.