Imaging agents and methods of imaging NAALADase or PSMA

An imaging method comprising the steps of:

• providing a radiolabeled compound according to the formula:
• wherein
• R is selected from the group consisting of fluoroalkyl, aryl, benzyl, thiol, and alkylthiol, each of which is optionally substituted with an optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted alkanoyl, or optionally substituted aralky, optionally substituted alkoxy, optionally substituted aralkyloxy, or optionally substituted phenoxy, and the R group comprises one or more isotopes selected from 11C, 18F, 99Tc, 123I or any combination thereof;
• Q is hydrogen, optionally substituted alkyl, optionally substituted benzyl or optionally substituted phenyl;
• and
• Z is Q or a tetrazole;
• or a pharmaceutically acceptable salt thereof;
• contacting cells or tissues with the radiolabeled compound;
• and
• making a radiographic image.