Evaluation of the specific absorption rate among patients undergoing brain magnetic resonance imaging using 1.5 Tesla and 3 Tesla magnetic resonance imaging Machines in King Khalid University Hospital, Saudi Arabia

Magnetic Resonance Imaging (MRI) exposes patients to radiofrequency energy measured by the specific absorption rate (SAR), a key safety metric. This study aimed to compare SAR values in brain MRI scans performed at 1.5 Tesla (T) and 3 T to inform safer imaging practices. A retrospective analysis of 200 adult brain MRI scans (100 at 1.5 T and 100 at 3 T) from King Khalid University Hospital was conducted. Data included SAR, demographics, scan parameters, and contrast use. Statistical tests assessed differences (P < .05). Brain SAR was significantly higher in 1.5 T scans (mean = 3.01 W/kg) than in 3 T (mean = 1.37 W/kg). Higher SAR values were noted in females and younger patients. Factors like image type, sequence, weight, flip angle, and contrast use significantly impacted SAR. SAR is more influenced by imaging parameters and patient characteristics than MRI magnetic field strength. Personalized MRI protocols and SAR monitoring are essential for patient safety.