Comprehensive Multi-Dimensional MRI for the Simultaneous Assessment of Cardiopulmonary Anatomy and Physiology

Abstract

Diagnostic testing often assesses the cardiovascular or respiratory systems in isolation, ignoring the major pathophysiologic interactions between the systems in many diseases. When both systems are assessed currently, multiple modalities are utilized in costly fashion with burdensome logistics and decreased accessibility. Thus, we have developed a new acquisition and reconstruction paradigm using the flexibility of MRI to enable a comprehensive exam from a single 5–15 min scan. We constructed a compressive-sensing approach to pseudo-randomly acquire highly subsampled, multi-dimensionally-encoded and time-stamped data from which we reconstruct volumetric cardiac and respiratory motion phases, contrast-agent dynamics, and blood flow velocity fields. The proposed method, named XD flow, is demonstrated for (a) evaluating congenital heart disease, where the impact of bulk motion is reduced in a non-sedated neonatal patient and (b) where the observation of the impact of respiration on flow is necessary for diagnostics; (c) cardiopulmonary imaging, where cardiovascular flow, function, and anatomy information is needed along with pulmonary perfusion quantification; and in (d) renal function imaging, where blood velocities and glomerular filtration rates are simultaneously measured, which highlights the generality of the technique. XD flow has the ability to improve quantification and to provide additional data for patient diagnosis for comprehensive evaluations.

Volumetric abdominal perfusion measurement using a pseudo‐randomly sampled 3D fast‐spin‐echo (FSE) arterial spin labeling (ASL) sequence and compressed sensing reconstruction

“…The PI‐CS reconstruction was achieved by minimizing the following optimization function:…”

High‐dimensionality undersampled patch‐based reconstruction (HD‐PROST) for accelerated multi‐contrast MRI

“…The technique proposed in this article can potentially change conventional multi‐contrast imaging by making efficient use of the rich and redundant information available locally and temporally. Two applications were introduced in this study, nonetheless HD‐PROST stays generic and should be easily extendable to many MR applications where multiple contrasts are involved, such as conventional T 1 and T 2 mapping, perfusion imaging, 4D flow MRI, or low SNR applications such as arterial spin labeling …”

MR imaging of the fetal heart

“…Recently, a new acquisition and reconstruction paradigm using MRI was developed for simultaneous assessment of cardiopulmonary anatomy and physiology from a single 5–15‐minute scan in free‐breathing newborns . The authors used a compressed‐sensing approach to pseudorandomly acquire highly subsampled, multidimensionally‐encoded, and time‐stamped data from which they reconstructed volumetric cardiac and respiratory motion phases, contrast‐agent dynamics, and blood flow velocity fields .…”

“…Recently, a new acquisition and reconstruction paradigm using MRI was developed for simultaneous assessment of cardiopulmonary anatomy and physiology from a single 5–15‐minute scan in free‐breathing newborns . The authors used a compressed‐sensing approach to pseudorandomly acquire highly subsampled, multidimensionally‐encoded, and time‐stamped data from which they reconstructed volumetric cardiac and respiratory motion phases, contrast‐agent dynamics, and blood flow velocity fields . This technique, referred to as "XD flow," was applied for studying CHD anatomy, flows, and function, as well as the impact of respiration on flow and pulmonary perfusion and for assessing renal function by measuring renal artery bloody velocities and glomerular filtration rates .…”