MRI technologists deal with a lot of hidden system limits during daily scanning, and one of the most important—but least intuitive—is SAR . You’ve probably seen it before: “SAR limit reached” “Scan paused due to RF power limits” “Sequence modified to reduce SAR” Even when everything seems technically correct, the scanner can still slow you down. Understanding why this happens can make your workflow smoother and help reduce unexpected delays. What SAR Actually Means (In Real Terms) SAR stands for Specific Absorption Rate. In simple terms, it measures how much radiofrequency (RF) energy the patient is absorbing during a scan , and how much of that energy is turning into heat. A more practical way to think about it: SAR is the scanner’s way of tracking how “hard” it is working the patient’s body with RF pulses. It’s measured in: Watts per kilogram (W/kg) But on the console, you don’t really think in numbers—you think in warnings, scan delays, and sequence restrictions . Why SAR Limits Exi...