OEM Collimators,
manufactured to drawing.

A gamma camera cannot focus its photons. At the energies of SPECT and planar nuclear medicine imaging there is no lens and no mirror — the only way to form an image is to absorb every photon travelling on the wrong path. That is the task of the lead collimator: a matrix of precision channels admitting only the rays that arrive along the designed direction. It is the single component that defines what the detector is able to see.

Every collimator is a negotiated trade-off. Narrower, longer channels sharpen spatial resolution but admit fewer photons; wider, shorter ones collect more counts at the cost of detail. Septal thickness follows the isotope — the 364 keV photons of ¹³¹I demand far more lead between channels than the 140 keV of ⁹⁹ᵐTc. Matching channel geometry, septa, and hole length to the clinical task is the core discipline of SPECT collimator design.

The physics is unforgiving of manufacturing error. A clinical acquisition uses only a small fraction of the photons a patient emits, so small geometric deviations — channel angulation, septal thickness, pitch — translate directly into visible artifacts and lost resolution. This is why collimator manufacturing is measured in hundredths of a millimetre, and why every assembly is inspected against its drawing before it reaches a detector head.