Functional imaging with dynamic contrast-enhanced MRI (DCE-MRI) provides important physiological markers of permeability, perfusion and glomerular filtration rate (GFR), a measure of kidney function, without exposing patients to ionizing radiation. DCE-MR images are at the same time used for evaluation of anatomy. Functional markers from DCE-MRI, if computed accurately, would play a critical role in diagnosing and assessing the progression of a number of pediatric diseases including those compromising kidney function, liver diseases, tumors, and Crohn's disease. One of the most important applications of DCE-MRI is assessing kidney function (GFR) in hydronephrosis patients with obstruction. In the absence of GFR information, children who stand to benefit from immediate surgical reconstruction might be overlooked or delayed in receiving treatment, and those who might benefit from a more conservative approach (i.e., ?watchful waiting?) might receive an unnecessary surgical intervention. While the current reference standard, nuclear renography (MAG3), yields some useful diagnostic information, it is slow, provides low resolution, does not offer anatomic detail, and delivers potentially harmful ionizing radiation. There is a clinical need for accurate computation of quantitative functional markers. Unfortunately, current methods of DCE-MRI in neonates and children are less than optimal, and therefore, DCE-MRI is underutilized in clinical practice. The technical challenges include insufficient temporal resolution to capture fast arterial input function (AIF) dynamics (which are required for accurate computation of quantitative markers), unavoidable respiratory motion and bulk motion (which reduce image quality and significantly lower the accuracy of parameter estimates), and a lack of robust, fast, automated post processing techniques for accurate computation of markers. Thus, there is an urgent, unmet need to develop a motion-compensated, high spatiotemporal resolution DCE-MRI method addressing these challenges. The primary objective of this exploratory, three-year study, is three-fold: first, to develop and evaluate a new bulk and respiratory motion-compensated, high spatiotemporal resolution DCE-MRI technique for accurate estimation of functional markers; second, to further improve the robustness and speed of DCE-MRI using a fast, deep learning (DL) technique with integrated temporal prior for the reconstruction of motion-compensated, higher quality, high temporal resolution images; and third, to develop an automatic quantitative analysis pipeline including segmentation and tracer kinetic model-fitting using DL techniques for fast, robust and accurate quantification of functional markers. The successful completion of these aims will provide new, clinically important abdominal imaging capabilities, with real-time, motion-compensated image reconstruction and reliable real-time parameter estimation from high temporal and spatial resolution DCE-MRI. This work will extend the usefulness of DCE-MRI to pediatric patients who are unable to remain still in the scanner, and eliminate the need for repeated scans and sedation in infants. ! !
This project addresses the need to develop advanced methods of magnetic resonance imaging (MRI) to provide new, clinically important abdominal imaging capabilities, with real-time, motion-compensated image reconstruction and reliable real-time estimation of clinically important quantitative imaging markers from high temporal and spatial resolution DCE-MRI. These markers will be used to evaluate the extent of several disorders and would play a critical role in diagnosing and assessing the progression of a number of pediatric diseases including those compromising kidney function, liver diseases, tumors, and Crohn's disease. This work will extend the usefulness of DCE-MRI to pediatric patients who are unable to remain still in the scanner, and eliminate the need of repeated scans, sedation and anesthesia when imaging newborns with congenital abnormalities such as congenital hydronephrosis, which if left untreated, can result in permanent damage to the child's kidneys.
