Thank you for your inquiry on CMS1074v2, Excessive Radiation Dose or Inadequate Image Quality for Diagnostic Computed Tomography (CT) in Adults (Facility IQR). The initial population (denominator) for the measure specifies all CT scans in adults aged 18 years and older at the start of the measurement period that have a CT Dose and Image Quality Category and were performed during an inpatient hospitalization during the measurement period. The only exclusion from the initial population is cases where a CT scan with a CT Dose and Image Quality Category = full body. The measure is calculated on a facility level using one denominator and one numerator. We hope this helps.