Radiology Imaging

(a) A schematic of cycloidal computed tomography (not to scale, seen from top); by adding an array of beam stops in front of the detector, the setup is transformed into an edge-illumination x-ray phase-contrast imaging device. (b) A sinogram sampling grid for a rotation-only scheme. (c) A sinogram sampling grid for a cycloidal scheme. The grids are shown for one mask period and a subset of rotation angles; the combination of empty and filled circles shows the grids that would be achieved through fine lateral sampling (requiring dithering); the filled circles show the data that are sampled without dithering.

Pre-processing results. Image courtesy of Applied Sciences.

Fig. 1 The basis of high-sensitivity SPION imaging at ultra-low magnetic fields.

(A) Magnetization of 25-nm SPIONs (green), gadolinium CA (Gd-DTPA/Magnevist, blue), and water (red) as a function of magnetic field strength (B0). (B) Magnetization as a function of magnetic field strength (B0) in the ULF (<10 mT) regime for the materials shown in (A). Superparamagnetic materials, such as SPIONs, are highly magnetized even at ULF. Paramagnetic materials, such as CAs based on gadolinium, and body tissues (which typically have diamagnetic susceptibilities close to water) have absolute magnetizations that increase linearly with field strength. Curves in (A) and (B) were reproduced from data in (32, 53) and reflect the magnetic moment per kilogram of compound. (C) Highly magnetized SPIONs (brown) interact with nearby 1H spins in water, shortening 1H relaxation times, and causing susceptibility-based shifts in Larmor frequency. Image courtesy of Science Advances

Sanjiv Sam Gambhir, M.D., Ph.D.

"Our study demonstrates that a real-world lung cancer screening can perform similar to randomized controlled trials in regard to important performance metrics," the UPenn authors of this AJR article concluded. Image courtesy of American Journal of Roentgenology (AJR)