SPECT
Single-Photon Emission Computed Tomography — gamma camera rotates around the patient acquiring projection data, reconstructed into 3D functional images of injected single-photon-emitting radiotracers (Tc-99m, Tl-201, I-123, In-111). Distinct from PET (positron annihilation, coincident photon-pair detection) — different physics, different tracers, different equipment.
SPECT / CT combines a SPECT camera with a CT scanner on a shared couch — attenuation correction and anatomic localization. Diagnostic-quality CT (Symbia Intevo, Discovery NM/CT 670) versus low-dose attenuation-correction-only CT (Infinia Hawkeye, Symbia Evo) is a meaningful tier split.
Why it matters to buyers: Core nuclear-medicine modality. Cardiac perfusion (Tc-99m sestamibi / tetrofosmin), bone scans (Tc-99m MDP), thyroid / parathyroid, renal, hepatobiliary, pulmonary V/Q, tumor scintigraphy. Cardiac CZT cameras (Discovery NM 530c, D-SPECT) cut acquisition time and dose substantially versus general-purpose Anger cameras.
Why it matters to engineers: Collimator selection (LEHR / LEAP / LEUHR / pinhole / parallel-hole) drives sensitivity / resolution trade-off per study. Energy resolution and camera uniformity drive image quality — daily flood QC catches drift. Center-of-rotation (COR) calibration affects SPECT reconstruction quality on every study.