Modulated Imaging (MI) is a fast, scan-free method that enables one to image and quantify the optical properties of turbid media. The technology can simultaneously map surface and sub-surface tissue structure, function and composition. Based on frequency-domain measurement principles, MI uses spatially-periodic or "structured" illumination and camera-based detection to separate and quantify the absorption, scattering, and fluorescence optical properties over a wide field-of-view (many cm) without the need for sample contact. Resolution is depth-dependent and thus scalable (sub-millimeter to millimeter), with depth sensitivity up to a few cm. This method has particularly strong potential for in-vivo clinical and pre-clinical imaging, where optical properties at several wavelengths provide quantitative information on endogeneous chromophore concentrations (i.e. oxy- and deoxy-hemoglobin, fat, and water). These parameters reflect quantitative, localized tissue status such as blood volume, tissue oxygenation, and edema. Using multispectral MI instrumentation, demonstrations of two in-vivo applications are investigated: (1) pre-clinical functional imaging of brain injury in a rodent model and (2) clinical imaging spectroscopy of human skin. Also, preliminary 3D fluorescence tomography data suggest that MI may provide a convenient, low-cost platform for localizing and quantifying exogenous molecular probes in-vivo.

Modulated Imaging (MI) is a recently reported method for rapid, non-invasive quantification of tissue optical properties (reduced scattering, μʹs and absorption, μ[subscript a]), which can be performed across a range of optical wavelengths to determine chromophore concentrations. In this thesis, development and characterization of a compact, low cost MI system is reported, using off-the-shelf hardware components with a custom software interface capable of easy modification for specific applications. This prototype setup consists of a color CCD camera which captures the diffusely reflected light from an object illuminated with patterns generated by a miniature projector. Broadband white light from the projector is delivered through a filter wheel containing narrowband filters for measurement at 420nm, 570nm, and 620nm wavelengths. A software application in MATLAB was written to control and synchronize the phase-shifted illumination patterns with image acquisition, and perform processing of image data into optical property maps. System accuracy was characterized by measuring a series of tissue simulating phantoms fabricated with varying μʹs and μ[subscript a], with both the prototype platform and a commercially available MI system as a reference. The overall error of the prototype system, for μʹs ranging from 0.93-2.23mm-1 and μa ranging from 0.009-0.049mm-1, was approximately 10% and 16%, respectively. Utilizing a lookup table that requires measurements at two illumination spatial frequencies instead of performing a least-squares fit to diffuse reflectance measurements at ten frequencies reduced the acquisition and processing time by 80%, while reducing the accuracy of optical property determination by approximately 3%. In summary, a prototype MI platform was developed and shown to be capable of quantifying the optical properties within biologically relevant μʹs and μa ranges. The system was assembled for less than 10% of the cost of commercially available systems while enabling individual components to be upgraded for a wider range of accurate optical property determination. Scattering and absorption maps obtained at multiple wavelengths can subsequently be used to quantify the concentrations of various tissue chromophores including hemoglobin, water, and lipids. Non-invasive, image based acquisition of such information may have impact in medical applications, ultimately improving patient health through disease characterization and monitoring progress of treatment.

This book demonstrates the concept of Fourier ptychography, a new imaging technique that bypasses the resolution limit of the employed optics. In particular, it transforms the general challenge of high-throughput, high-resolution imaging from one that is coupled to the physical limitations of the optics to one that is solvable through computation. Demonstrated in a tutorial form and providing many MATLAB® simulation examples for the reader, it also discusses the experimental implementation and recent developments of Fourier ptychography. This book will be of interest to researchers and engineers learning simulation techniques for Fourier optics and the Fourier ptychography concept.

This open access book gives a complete and comprehensive introduction to the fields of medical imaging systems, as designed for a broad range of applications. The authors of the book first explain the foundations of system theory and image processing, before highlighting several modalities in a dedicated chapter. The initial focus is on modalities that are closely related to traditional camera systems such as endoscopy and microscopy. This is followed by more complex image formation processes: magnetic resonance imaging, X-ray projection imaging, computed tomography, X-ray phase-contrast imaging, nuclear imaging, ultrasound, and optical coherence tomography.

By introducing the superspace formalism, the methods of structure analysis of incommensurate structures have achieved in the past few years a full maturity. The superspace description is also becoming in the field of quasicrystals the main tool to approach a systematic method of structure determination of these materials. According to the program of the Workshop, these proceedings are an introduction to the formalism and practice of structure determination of modulated structures (incommensurate and commensurate) and quasiperiodic systems, mainly under the unifying framework of the superspace description. Accordingly, a large set of tutorial introductory chapters written by well-known specialists are included. The main refinement programs available for incommensurate structures are presented by their authors. The book also contains the most recent contributions from more than thirty of the participants in the Workshop, focusing on the problem of the structure analysis of these typical materials by means of diffraction methods.

Presents the technical aspects of IMRT, and the clinical aspects of planning and delivery. The volulme explores a practical approach for radiation oncologists and medical physicists initiating or expanding and IMRT program, the fundamental biology and physics of IMRT, a site-by-site review of IMRT techniques with clinical examples, and reviews of published outcome studies.