Technical note: Quantitative optimization of the FLAIR sequence in post mortem magnetic resonance imaging.

Area of Science:

• Medical Imaging
• Radiology
• Forensic Science

Background:

• Fluid Attenuated Inversion Recovery (FLAIR) MRI suppresses cerebrospinal fluid (CSF) signal at a specific null point inversion time (TI_null).
• Post mortem FLAIR imaging is challenged by temperature-dependent TI_null due to reduced body temperature.
• Accurate CSF signal suppression in post mortem FLAIR requires temperature correction of TI_null.

Purpose of the Study:

• To investigate the effect of temperature on post mortem TI_null for FLAIR MRI.
• To establish a method for robust CSF signal suppression in in situ post mortem MRI.
• To determine the temperature dependency of TI_null in deceased subjects.

Main Methods:

• Nine deceased subjects underwent in situ 3T MRI brain examinations.
• FLAIR sequences with varying inversion times were used to quantitatively determine TI_null of CSF.
• Brain and rectal temperatures were measured before MRI scans.

Main Results:

• A significant positive linear relationship was observed between TI_null of CSF and brain temperature.
• A significant positive linear relationship was also found between TI_null of CSF and rectal temperature.
• These findings demonstrate a clear temperature dependency of TI_null in post mortem subjects.

Conclusions:

• The established linear relations enable correction of TI_null based on measured body temperature.
• This temperature correction is crucial for optimizing CSF signal suppression in post mortem FLAIR MRI.
• The study provides a basis for more accurate and reliable post mortem FLAIR imaging.