Because it can be measured directly on the patient's surface using specialized tools like thermoluminescent dosimeters (TLD) or calculated via mathematical models, it serves as the primary benchmark for quality control in radiology departments. Why Entrance Dose Matters

Entrance skin dose | Radiology Reference Article | Radiopaedia.org

: Radiation that bounces back toward the skin from the patient's internal tissues, the examination table, or the detector.

ESD is the absorbed radiation dose (measured in ) at the intersection of the X-ray beam's central axis and the patient’s skin. Unlike deep-tissue measurements, ESD includes: Primary Radiation : The initial photons from the X-ray tube.

Understanding and managing this metric is a cornerstone of the principle (As Low As Reasonably Achievable), ensuring diagnostic-quality images are obtained with minimal radiation risk. What is Entrance Skin Dose (ESD)?