Infographics / Nuclear Medicine

Planar vs SPECT vs PET advantages

A comparison table of three nuclear-medicine imaging methods drawn from the question explanations. Columns are PET, SPECT and planar (conventional gamma) imaging. Rows compare collimation, sensitivity, spatial resolution, image noise, contrast, attenuation correction, output, acquisition geometry and patient dose. PET uses electronic (coincidence) collimation with the best spatial resolution (about 4 to 6 mm) and lowest noise. SPECT uses a rotating mechanical lead collimator, giving worse resolution (about 8 to 12 mm) and the highest noise, but improves contrast over planar and allows attenuation correction and 3D reconstruction. Planar gamma imaging uses a fixed camera, has higher sensitivity than SPECT and better resolution than SPECT, but only a 2D projection with poor contrast and no reliable attenuation correction.

PET vs SPECT vs planar gamma imaging — property comparison A comparison table of three nuclear-medicine imaging methods drawn from the question explanations. Columns are PET, SPECT and planar (conventional gamma) imaging. Rows compare collimation, sensitivity, spatial resolution, image noise, contrast, attenuation correction, output, acquisition geometry and patient dose. PET uses electronic (coincidence) collimation with the best spatial resolution (about 4 to 6 mm) and lowest noise. SPECT uses a rotating mechanical lead collimator, giving worse resolution (about 8 to 12 mm) and the highest noise, but improves contrast over planar and allows attenuation correction and 3D reconstruction. Planar gamma imaging uses a fixed camera, has higher sensitivity than SPECT and better resolution than SPECT, but only a 2D projection with poor contrast and no reliable attenuation correction. Nuclear-medicine modalities these questions contrast Cells state only what the explanations assert; an em dash means the pairing was not compared. PET SPECT planar (gamma camera) Collimation electronic (coincidence) mechanical (lead) mechanical (lead) Sensitivity / counts high (no collimator) low higher than SPECT Spatial resolution best, ≈4–6 mm worst, ≈8–12 mm better than SPECT Image noise lower than SPECT highest lower than SPECT Contrast (target:bg) — improved (tomographic) low (superimposed) Attenuation correction yes (μ map) yes (μ map) no reliable Output 3D volume 3D volume 2D projection Acquisition coincidence detection rotating camera fixed camera Patient dose ≈ SPECT ≈ PET — All three are ionising radionuclide methods; they differ in photon detection, not radiation type.
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