Amide Proton Transfer Imaging for Brain Tumors: Initial Experience and Current Status

(Educational Exhibit, RSNA 2018)
V Mahajan, MBBS, MBA; R Bhattacharjee, MENG; I Saha, PhD; H Mahajan, MD; S Panwar, MD; V Venugopal, MD

TEACHING POINTS

• Amide Proton Transfer (APT) Images contain quantitative colour maps that show protein / peptide content.
• APT imaging is able to accurately predict tumour grade in pre-surgical cases.
• APT imaging is showing promise in differentiating tumour recurrence from radiation necrosis.
• APT imaging can be used in combination with Susceptibility Weighted Imaging (SWI) based ITSS (Intra-Tumoral Susceptibility Score) to predict tumour grade when compared to Contrast-Enhanced Perfusion MRI.
• Some fundamental problems with the APT acquisition need to be addressed for it to come into day-to-day clinical practice, especially with respect to quantification and artefacts.

TABLE OF CONTENTS/OUTLINE

• Review of current brain tumour MR imaging protocols
• Mechanism behind APT imaging
• Review of current clinical literature on APT imaging for brain tumors
• APT for tumour recurrence vs radiation necrosis
• APT in glioma grading
• APT with SWI-based ITSS as a non-contrast replacement for CE-Perfusion MR
• Limitations and future directions for APT imaging in the brain