Quantum‑correlated photon imaging experiments first used pairs of entangled photons so that an image was recovered only from correlations between the two detection paths rather than from either beam alone. Similar correlation and entanglement ideas have been attempted for higher energies and to positron‑annihilation photons, motivating quantum‑based Positron Emission Tomography (PET) concepts in which the additional quantum information carried by annihilation photon pairs could enhance image quality or add new types of contrast beyond conventional PET. In parallel, quantum‑inspired transmission imaging has been proposed as an alternative to Computed Tomography (CT), which today relies on a well‑characterized but fundamentally stochastic X‑ray source, and is limited by Poisson photon statistics, dose requirements, and capped contrast for soft‑tissue. Traditional X‑ray and CT imaging are governed by Poisson statistics, where independent, random photon arrivals make the variance equal to the mean, and has fundamentally bound SNR for a given dose. Research on quantum‑correlated transmission schemes has looked at image formation with higher‑order correlations between photons (rather than simple independent counting) such that performance is no longer capped by standard Poisson statistics, which can in principle lead to superior SNR and sharper anatomical detail at a given dose. To date, quantum‑based X‑ray implementations of this idea have largely relied on spontaneous parametric down‑conversion (SPDC) to generate entangled or correlated photon pairs, but SPDC at X‑ray‑level energies has extremely low conversion efficiency and pair rates—often only a few pairs per second—rendering such medical or biological imaging impractical. Quantum correlation of Annihilation Photon Imaging (QAPI) brings the correlation concepts into a PET‑like regime by using positron annihilation as a bright source of 511 keV gamma‑ray pairs while assuming a transmission‑imaging role similar to CT. QAPI is designed to exploit the strengths of both worlds: unlike CT, it can count the incident annihilation photons via the idler channel and operate in a high‑transmission regime that permits binomial transmission statistics. The PET‑like 511 keV photons introduce challenges that do not exist for CT, including low interaction probability in tissue and detectors, reduced single‑photon detection efficiency, and the need for precise coincidence timing between the signal and idler counts. For any high‑energy, photon-based imaging, including emerging quantum schemes, there is a fundamental tension between dose (especially for biological tissues that are highly susceptible to damage, cell death, or mutation when exposed to ionizing radiation) and the photon statistics needed for adequate SNR. Moreover, the dose‑normalized performance for quantum approaches is still not well established.