In addition to the services the Human Imaging Core provides using established technologies, a number of developmental projects are under way. These projects, many of which are being done in collaboration with existing Mayo imaging research resources, are based on firm preliminary studies and are intended to lead to new or enhanced services within the core.
Multiparametric image registration
Goal: Enhance traditional multiparametric classifiers (MPCs), via the use of additional time points, to measure change over time.
Being able to measure change over time is an important capability when investigating disease and assessing therapy effects. While MPCs have traditionally been used to classify tissues from a single time point, registration of exams over time allows this technology to classify changing tissues.
Library of candidate features
Goal: Develop a library of candidate features (e.g., intensity on multiple image types at multiple time points; textures; gradients; clinical data-like patient age) and create a predictive model.
The library would be “trained” to recognize cases where there has been little disease progression (or a good response to therapy) versus those with much disease progression (or a poor response to therapy). The resulting predictive model would use imaging data over time to more quickly identify and predict desired measures, such as a favorable response to medication or intervention.
Identification of parenchymal volumes using unenhanced magnetic resonance (MR) imaging
Goal: Develop a more accurate and automated method for measuring total renal volume, and computing parenchymal and cyst volume.
To date, the ability to determine subsets of renal parenchyma and renal volumes has been elusive, but new imaging techniques developed in the core should lead to a reliable method.
MR elastography of the liver and kidney
Goal: Use MR elastography to determine if autosomal-dominant PKD (ADPKD) affects the renal or hepatic parenchyma in yet undefined ways.
MR elastography of the abdomen makes it possible to quantify tissue stiffness in vivo. Although this technology may be more appropriate for following the course of liver disease in patients with autosomal-recessive PKD (ARPKD) and congenital hepatic fibrosis, it can easily be applied to imaging of relatively spared areas of the kidney or liver in ADPKD patients.
Dual-energy computed tomography (CT) renal stone and calcification analysis
Goal: Use dual-energy CT technology to quantitatively and qualitatively characterize the stone, parenchyma and vascular calcification burdens of polycystic kidneys.
Renal stones, and renal parenchyma/cyst and vascular calcifications, are known to form in polycystic kidneys. Renal calculi, and possibly renal parenchyma calcifications, are known to vary in composition and radiographic density. Recent research has demonstrated that renal stones of differing composition can be delineated with dual-energy CT technology. Better characterization will also allow for the determination of whether calcifications are associated with structural and functional disease severity, and/or the rate of disease progression.
Automated detection and characterization of cerebral artery aneurysms
Goal: Better predict the risk of aneurysm rupture in ADPKD patients.
PKD is associated with an increased risk for intracranial aneurysms, but whether these aneurysms in ADPKD have a higher risk of rupture than those in the general population is not known (a long-term follow-up study of asymptomatic aneurysms detected by presymptomatic screening in ADPKD at Mayo does not suggested an increased risk).
The core is interested in identifying aneurysm shape or flow patterns that can be correlated with the risk of rupture, and then comparing the intracranial aneurysms in the ADPKD population with those in the general population to see if there is a difference in shape or flow, and whether this results in a better ability to predict rupture risk. Methods utilized may include computational fluid dynamics, MR angiography and CT angiography.
Goal: Use vascular ultrasound to better understand PKD patients' relative degrees of vascular disease.
Recent advancements in vascular ultrasound have led to high-resolution imaging of vessel walls that allow for the accurate measurement of the thickness of the intima and media layers. These new techniques have been applied to the carotid artery in an attempt to measure overall risk for cardiovascular disease in high-risk patients. Applying these new technologies to the carotid and renal arteries of PKD patients may shed light on their relative degrees of vascular disease.
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