Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
library:specific_absorption_rate [2025/06/21 18:44] – scottlibrary:specific_absorption_rate [2025/06/21 18:51] (current) – scott
Line 15: Line 15:
 On even relatively older scanners, SAR is tracked throughout the scan, typically in 15 minute intervals. If the scanner senses SAR limits being exceeded, scanning will be prohibited and a 'cool down' time will have to elapse before scanning can resume. When scanning veterinary patients, body weights are typically far lower than the SAR model was meant to be used with, leading to inaccurate estimates and SAR errors preventing scanning unnecessarily. Additionally, animals under anesthesia do not have the same thermoregulatory capacity as when they're awake, often leading to patients being too cold despite what the scanner SAR level reads. Generally, the best approach is to maintain adequate patient temperature with blankets and warmers, and mitigate SAR errors so they don't prolong anesthesia time. On even relatively older scanners, SAR is tracked throughout the scan, typically in 15 minute intervals. If the scanner senses SAR limits being exceeded, scanning will be prohibited and a 'cool down' time will have to elapse before scanning can resume. When scanning veterinary patients, body weights are typically far lower than the SAR model was meant to be used with, leading to inaccurate estimates and SAR errors preventing scanning unnecessarily. Additionally, animals under anesthesia do not have the same thermoregulatory capacity as when they're awake, often leading to patients being too cold despite what the scanner SAR level reads. Generally, the best approach is to maintain adequate patient temperature with blankets and warmers, and mitigate SAR errors so they don't prolong anesthesia time.
  
-====Reducing SAR While Scanning====+====Reducing SAR====
  
 The first part of knowing how to reduce SAR errors is knowing where and when they are likely to occur: The first part of knowing how to reduce SAR errors is knowing where and when they are likely to occur:
Line 24: Line 24:
   * Large axial stacks of T1's   * Large axial stacks of T1's
   * Post contrast imaging: lots of T1's back to back   * Post contrast imaging: lots of T1's back to back
 +  * Very high bandwidth sequences; results in shorter spacing between RF pulses
  
 SAR reduction strategies are pretty straightforward: reduce the amount, frequency, and strength of RF pulses!  SAR reduction strategies are pretty straightforward: reduce the amount, frequency, and strength of RF pulses!