Recognition of Delayed Hypoxic Leukoencephalopathy after a Severe Drug Overdose Using a Divided Subtracted Inversion Recovery (dSIR) Sequence

Motivation: Divided Subtracted Inversion Recovery (dSIR) sequences can show subtle abnormalities due to small increases in T1 that are not seen with conventional sequences,Goal(s): To use dSIR sequences to examine the brain in a patient nine months after severe drug overdose associated with prolonged hypoxia and compare the dSIR images with T2-FLAIR images. Approach: MRI scans obtained on an 18-y/o male control and a 19-y/o male patient. 2D IR FSE sequences were performed with TIs chosen to null WM, and a longer TIi producing dSIR images. Results: Widespread abnormalities seen on dSIR images in areas of WM that appeared normal on T2-FLAIR images. Impact: In a patient imaged nine months after a severe drug overdose, dSIR images showed extensive abnormalities in white matter that appeared normal on T2-FLAIR images. Widespread white matter changes may be common unrecognised sequelae of severe drug overdoses.