# Estimating ROI activity concentration with photon-processing and photon-counting SPECT imaging systems

> Research article (Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE, 2015) · cited 18× · AI/ML

**Wikidata**: [openalex:W2002676832](https://www.wikidata.org/wiki/openalex:W2002676832)  
**Source**: https://4ort.xyz/entity/estimating-roi-activity-concentration-with-photon-processing-and-photon-counting-spect-imaging-systems