Structured ultrasound microscopy

Abstract

Bone marrow stromal cell (BMSC)-mediated endochondral bone formation may be a promising alternative to the current gold standards of autologous bone transplantation, in the development of novel methods for bone repair. Implantation of chondrogenically differentiated BMSCs leads to bone formation in vivo via endochondral ossification. The success of this bone formation in an allogeneic system depends upon the interaction between the implanted constructs and the host immune system. The current study investigated the effect of chondrogenically differentiated human bone marrow stromal cell ---------------------------------------------------------This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Coding Mask Design for Single Sensor Ultrasound Imaging

“…However, it is impossible to pre-compute A s if it is not known what pressure field is emitted by each scatterer, which in turn can only be known if the transmit mask is known. Although in [22], [23] we used the same mask in transmit and receive, in this work we assume that a separate (co-located) transducer is used for transmit, and the masked transducer for receive. This makes it always possible to pre-compute any A s using (4), circumventing this problem.…”

“…For example, the sensor and the mask can be rotated (as in [22]), or translated (as in [23]) to obtain additional information of x. Note however, that the same mask is used in each case, and that A(w) is still linear in w.…”

“…We recently demonstrated a similar approach for 3D ultrasound imaging [22], [23], where we have shown how a single sensor with a 'coding mask' can successfully reconstruct 3D objects from multiple pulse-echo measurements, facilitating the design of new imaging devices with reduced output data. Instead of placing a heterogeneous scattering medium in front of the single sensor, we used a homogenous, but irregularly shaped piece of plastic, to which we refer as a 'coding mask' (Fig.…”

Joint Optimization of Coding Mask and Scan Positions for Compressive Single Sensor Imaging

“…As an extension of this idea, we recently showed a single sensor with a coding mask that is translated in space [12]. By moving the sensor to a different position, more information about the image target is obtained.…”

“…In our works so far, we have only considered using a randomly shaped coding mask, and in [12] we also used randomly selected sensing positions. However, it is not known how optimal a random setup performs, or whether a performance increase is possible using a deterministic design.…”