Designing contrasts for rapid, simultaneous parameter quantification and flow visualization with quantitative transient-state imaging

TL;DR

This paper introduces a novel MRI technique that rapidly acquires contrast-weighted images and quantitative parameter maps simultaneously, enhancing diagnostic information without increasing scan time.

Contribution

It presents a new model, sequence design, and reconstruction method enabling concurrent contrast imaging and quantitative mapping in a single accelerated MRI acquisition.

Findings

Simultaneous angiography and quantitative maps achieved

Enhanced clinical biomarker exploration without extra scan time

Improved data richness for MRI diagnostics

Abstract

Magnetic resonance imaging (MRI) is a remarkably powerful diagnostic technique: it generates wide-ranging information for the non-invasive study of tissue anatomy and physiology. Complementary data is normally obtained in separate measurements, either as contrast-weighted images, which are fast and simple to acquire, or as quantitative parametric maps, which offer an absolute quantification of underlying biophysical effects, such as relaxation times or flow. Here, we demonstrate how to acquire and reconstruct data in a transient-state with a dual purpose: 1 - to generate contrast-weighted images that can be adjusted to emphasise clinically relevant image biomarkers; exemplified with signal modulation according to flow to obtain angiography information, and 2 - to simultaneously infer multiple quantitative parameters with a single, highly accelerated acquisition. This is a achieved by introducing three novel elements: a model that accounts for flowing blood, a method for sequence design that incorporates both parameter encoding and signal contrast, and the reconstruction of temporally resolved contrast-weighted images. From these images we simultaneously obtain angiography projections and multiple quantitative maps. By doing so, we increase the amount of clinically relevant data without adding measurement time, creating new dimensions for biomarker exploration and adding value to MR examinations for patients and clinicians alike.