Brian Curtis Lee, Presenter: Nothing to Disclose

Susan Ng, Abstract Co-Author: CEO, Real Time Tomography, LLC

Johnny Kuo PhD, Abstract Co-Author: Employee, Real Time Tomography, LLC

Peter A Ringer BS, Abstract Co-Author: Employee, Real Time Tomography, LLC Shareholder, Real Time Tomography, LLC

Andrew D.A. Maidment PhD, Abstract Co-Author: Research support, Hologic, Inc Research support, Barco nv Spouse, Employee, Real-Time Radiography, Inc Spouse, Stockholder, Real-Time Radiography, Inc

To explore the feasibility of performing four-dimensional dynamic contrast-enhanced tomosynthesis (4D DCE-DT).

A custom bench-top tomosynthesis system was designed and built to perform 4D DCE-DT. The system consists of a stationary x-ray source and selenium x-ray detector, and a computer-controlled filter wheel with a variety of filter materials and thicknesses; phantoms are mounted on a rotary stage set atop of an x-y linear translation stage. A computer system coordinates all components, including a contrast injector. Images are acquired using a slow-scanning method in which each projection image is acquired after a fixed delay. Between each acquisition the phantom orientation is changed; it is also possible to change the x-ray energy and filter type, as well as perform injections. Both temporal and dual-energy subtraction are supported. Real-time reconstructions are performed by backprojection filtering using a customized commercial software package. A dynamic flow phantom was constructed and imaged to test the feasibility of 4D DCE-DT. One projection was acquired per energy per angle per timepoint and reconstructions were performed on subsets of these images; e.g., if projections 1 through N are used in the reconstruction for one timepoint, projections 2 through N+1 are used for the next timepoint.

Real-time reconstruction is possible to allow viewing of arbitrary tomographic planes and timepoints. Measured data from reconstructed waveforms of iodine concentration over time observed in the dynamic flow phantom matched the expected iodine concentration over time after convolution with a square wave with width equal to the number of projections per reconstruction. Experiments involving binary pulses of iodine (simulating the movement of a bolus of iodine through a vessel) confirmed the linearity and shift-invariance of the system. It can be observed that as the number of projections per timepoint/reconstruction decreases an increase in temporal resolution is achieved at the cost of a decrease in tomographic ability.

4D dynamic contrast-enhanced tomosynthesis can be performed in a dose-efficient fashion. 

4D dynamic contrast-enhanced tomosynthesis should allow for measurement of both spatial and temporal characteristics of blood flow and lesion perfusion.

Lee, B, Ng, S, Kuo, J, Ringer, P, Maidment, A, Dynamic Four-dimensional Contrast-enhanced Tomosynthesis .  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13027822.html