This estimator is provided as an educational planning tool for preliminary shielding design estimates only. Results must be verified and approved by a Qualified Medical Physicist (QMP) before implementation. Radiology Physics LLC assumes no liability for shielding designs based solely on this estimator. Final designs must comply with all applicable regulatory requirements and account for site-specific factors including geometry, structural considerations, and regulatory review. This tool is not intended for regulatory submission or compliance documentation. Use of this tool does not establish a physicist-client relationship with Radiology Physics LLC. Estimates are based on published reference data and simplified models that may not capture all site-specific conditions. SPECT and SPECT/CT modules reflect Tc-99m radionuclide shielding only; CT components must be evaluated separately using the CT Scanner module. PET/CT estimates are limited to adjacent-barrier shielding from uptake and imaging-room occupancy; floor/ceiling and whole-clinic evaluations require site-specific review by a QMP. This estimator does not replace a site-specific shielding design, post-construction survey, or signed report by a Qualified Medical Physicist.