Allison Johnsen MD, Presenter: Nothing to Disclose

Jared Weis PhD, Abstract Co-Author: Nothing to Disclose

Abigail Searfoss, Abstract Co-Author: Nothing to Disclose

Geoffrey Eugene Wile MD, Abstract Co-Author: Nothing to Disclose

Thomas Yankeelov PhD, Abstract Co-Author: Research Consultant, Eli Lilly and Company

Michael Miga PhD, Abstract Co-Author: Nothing to Disclose

Richard Glenn Abramson MD, Abstract Co-Author: Consultant, ICON plc Board Member, Partners in the Imaging Enterprise LLC

Conventional magnetic resonance elastography (MRE) of the liver requires an external device for generating mechanical shear waves. We developed a novel MRE methodology that takes advantage of natural diaphragmatic respiratory motion to assess liver mechanical properties. The approach uses a model-based reconstruction algorithm to estimate mechanical elasticity using MR image volumes acquired under different states of deformation. The purpose of this initial investigation was to demonstrate this methodology for assessing liver fibrosis in cirrhotic and non-cirrhotic subjects.

Technique was developed using normal volunteer subjects on a 3 T research scanner (Phillips Healthcare, Best, The Netherlands) and subsequently deployed on a patient with cirrhosis undergoing clinical MR imaging on a Phillips 1.5 T MR scanner. Each MR examination included breath-hold modified DIXON (mDixon) sequences acquired in sagittal plane at both end-inspiration and end-expiration (1.3 × 1.3 × 3.0 mm voxel resolution). Post-processing elastography images were then generated through the use of a modality independent elastography (MIE) reconstruction optimized for liver parenchymal deformation induced by diagphragmatic respiratory motion.

Post-processing with a MIE reconstruction yielded a map of the spatial distribution of stiffness within the liver, kidney, and surrounding adipose tissue. The cirrhotic patient exhibited significant focal heterogeneity of liver stiffness with areas approximately two-fold greater than background liver stiffness values. Mean stiffness of the cirrhotic liver, normalized to fat, was 1.64 times greater than mean liver stiffness in a normal volunteer.

A MRE approach based on diaphragmatic motion yielded plausible results in this initial attempt to assess cirrhotic and non-cirrhotic livers. These preliminary results indicate the potential for this approach to provide non-invasive assessment of liver stiffness without the use of external hardware. Further study is warranted.

Diaphragmatic motion-based magnetic resonance elastography has the potential to provide valuable information on liver stiffness without the use of external hardware. 

Johnsen, A, Weis, J, Searfoss, A, Wile, G, Yankeelov, T, Miga, M, Abramson, R, Preliminary Investigation of Diaphragmatic Motion-based Magnetic Resonance Elastography for Assessing Liver Fibrosis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14018600.html