Traditional Posters: Body Imaging

Body Diffusion

Hall B Wednesday 13:30-15:30

2645. Effect of Region of Interest Position on Liver Apparent Diffusion Coefficient.

Daniel Wilson¹, J. Ashley Guthrie², Janice Ward<sup>2

1</sup>Medical Physics, Leeds Teaching Hospitals NHS Trust, Leeds, West Yorkshire, United Kingdom; ²Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, West Yorkshire, United Kingdom

The liver ADC was measured in 3 different positions in the liver in 33 subjects. The mean ADC was signficantly different between the 3 different positions. This is attributed to the presence of noise in the middle of the liver and artefactual signal loss at high b-values at superior positions in the left lobe. Care must be taken when measuring ADC in the liver.

2646. Continuously Moving Table Whole-Body MRI Using Variable Field of View

Robert L. Janiczek^1,2, Jonathan W. Howard², Giulio Gambarota², John S. Thornton¹, Xavier Golay¹, Rexford D. Newbould<sup>2

1</sup>Institute of Neurology, University College London, London, United Kingdom; ²GSK Clinical Imaging Centre, London, United Kingdom

Continuously moving table (CMT) acquisitions have been proposed whereby data are collected in a hybrid space as the patient moves through the scanner. In CMT acquisitions the table velocity and therefore scan duration is proportional to the in-plane FOV. This work investigates the use of varying the FOV as a function of patient position in order to reduce scan time. A low-resolution scout scan is used to design a k-space sampling pattern that matches the minimal FOV requirement. The use of a variable FOV CMT acquisition is shown to reduce scan time by 32% over a conventional constant FOV design.

2647. Diffusion-Weighted Imaging of the Abdomen with Readout-Segmented (RS)-EPI

Samantha J. Holdsworth¹, Stefan Skare¹, Shreyas S. Vasanawala¹, Roland Bammer<sup>1

1</sup>Radiology, Stanford University, Palo Alto, CA, United States

Diffusion-weighted imaging (DWI) in the abdomen has proven useful for the various pathologies including liver lesion characterization and diagnosis of diffuse renal disease. However, image distortions arising from the use of EPI has shown to be problematic. In this work we explore the use of readout-segmented (RS)-EPI for DWI of the abdomen and show that it may be a useful method for reducing geometric distortion and blurring.

2648. A Novel Whole Body Diffusion Weighted Imaging Technique with Continuously Moving Table: Preliminary Results

Yeji Han¹, Sandra Huff¹, Juergen Hennig¹, Ute Ludwig<sup>1

1</sup>Medical Physics, Dept. of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany

Superior disease contrast and no need for extra administration of exogenous contrast medium contribute to the advantages of diffusion-weighted imaging (DWI) over other modalities for patient screening and treatment monitoring. However, the clinical impact of whole-body DWI (wbDWI) remains limited due to the technical difficulties of multistation approach. In this study, we have developed a continuously moving table (CMT) wbDWI method based on a STIR-EPI sequence as an alternative to currently used multistation wbDWI sequence. The preliminary results successfully demonstrate that CMT wbDWI can be a promising technique to overcome the problems of multistation wbDWI approach.

2649. Characterization of Multicompartmental Renal Diffusion Using a Stretched Exponential Model