Cardiac-induced motion of the pancreas and its effect on image quality of ultrahigh-resolution CT

• Type of Material: Article
• Authors: Thomas Wesley Holmes, Emory University; Zhou Yu, Canon Medical Research USA, Inc; Richard Thompson, Canon Medical Research USA, Inc; John Oshinski, Emory University; Amir Pourmorteza, Emory University
• Language: English
• Date: 2024-01-04
• Publisher: SpringerOpen (Springer Nature)
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2023
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): https://eurradiolexp.springeropen.com/articles/10.1186/s41747-023-00401-5
• Title of Journal or Parent Work: European Radiology Experimental
• Volume: 8
• Grant/Funding Information: This study was funded by a sponsored research agreement between Canon Medical Research USA and Emory University (PI: AP).
• Keywords: Artifacts; Tomography (x-ray computed); Magnetic resonance imaging; Healthy volunteers; Abdomen
• Research Categories: Engineering, Biomedical; Health Sciences, Radiology

Abstract

Recent advancements in diagnostic CT detector technology have made it possible to resolve anatomical features smaller than 20 LP/cm, referred to as ultra-high-resolution (UHR) CT. Subtle biological motions that did not affect standard-resolution (SR) CT may not be neglected in UHR. This study aimed to quantify the cardiac-induced motion of the pancreas and simulate its impact on the image quality of UHR-CT. We measured the displacement of the head of the pancreas in three healthy volunteers using Displacement Encoding with Stimulated Echoes (DENSE) MRI. The results were used to simulate SR- and UHR-CT acquisitions affected by pancreatic motion. We found pancreatic displacement in the 0.24–1.59 mm range during one cardiac cycle across the subjects. The greatest displacement was observed in the anterior–posterior direction. The time to peak displacement varied across subjects. Both SR and UHR images showed reduced image quality, as measured by radial modulation transfer function, due to cardiac-induced motion, but the motion artifacts caused more severe degradation in UHR acquisitions. Our investigation of cardiac-induced pancreatic displacement reveals its potential to degrade both standard and UHR-CT scans. To fully utilize the improvement in spatial resolution offered by UHR-CT, the effects of cardiac-induced motion in the abdomen need to be understood and corrected. Relevance statement Advancements in CT detector technology have enhanced CT scanner spatial resolution to approximately 100 µm. Consequently, previously ignored biological motions such as the cardiac-induced motion of the pancreas now demand attention to fully utilize this improved resolution.