Medical Imaging: Principles and Practices
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The discovery of x-ray, as a landmark event, enabled us to see the "invisible," opening a new era in medical diagnostics. More importantly, it offered a unique undestanding around the interaction of electromagnetic signal with human tissue and the utility of its selective absorption, scattering, diffusion, and reflection as a tool for understanding the physiology, evolution of disease, and therapy. With contributions from world-class experts, Medical Imaging: Principles and Practices offers a review of key imaging modalities with established clinical utilization and examples of quantitative tools for image analysis, modeling, and interpretation.
The book provides a detailed overview of x-ray imaging and computed tomography, fundamental concepts in signal acquisition and processes, followed by an overview of functional MRI (fMRI) and chemical shift imaging. It also covers topics in Magnetic Resonance Microcopy, the physics of instrumentation and signal collection, and their application in clinical practice. Highlights include a chapter offering a unique perspective on the use of quantitative PET for its applications in drug discovery and development, which is rapidly becoming an indispensible tool for clinical and research applications, and a chapter addressing the key issues around organizing and searching multimodality data sets, an increasingly important yet challenging issue in clinical imaging.
- X-ray imaging and computed tomography
- MRI and magnetic resonance microscopy
- Nuclear imaging
- Ultrasound imaging
- Electrical Impedance Tomography (EIT)
- Emerging technologies for in vivo imaging
- Contrast-enhanced MRI
- MR approaches for osteoarthritis and cardiovascular imaging
- PET quantitative imaging for drug development
- Medical imaging data mining and search
The selection of topics provides readers with an appreciation of the depth and breadth of the field and the challenges ahead of the technical and clinical community ofresearchers and practitioners.
the time dependence of the magnetic field gradient applied during the phase-encoding; and the integration is performed over time when the phase-encoding gradient is on. Thus, in one-dimensional phase encoding, if the phase encoding is along, for example, the y axis, the phase acquired becomes k × y = ∫ γ gy(t) × y dt. The acquired signal S(t) is the integral of the spatially distributed signals modulated by a spatially dependent phase, given by the equation ∫ S(t ) = ρ(r , t )e(ik ⋅r )d3r
quality are summarized in Figure 1.1. This is a one-dimensional profile of x-ray transmission through a simplified computer model of the breast (Fahrig et al., 1992), illustrated in Figure 1.2. A region of reduced transmission corresponding to a structure of interest such as a tumor, a calcification or normal fibroglandular tissue is shown. The imaging system must have sufficient spatial resolution to delineate the edges of fine structures in the breast. Structural detail as small as 50 μm must
is placed at the back of the scintillation crystal. When a photon hits and interacts with the crystal, the scintillation generated will be detected by the array of PMTs. An electronic circuitry evaluates the relative signals from the PMTs and determines the location of interaction of the incident photon in the scintillation crystal. In addition, the scintillation cameras have built-in energy discrimination electronic circuitry with finite energy resolution that provides selection of the photons
3D model of the collimator–detector response is used. Nuclear Medicine 4-27 CT image for accurate attenuation compensation and a 2D model of the collimator–detector response for accurate collimator–detector response compensation. The reconstructed image in Figure 4.13d is similar to that in Figure 4.13b except that the Metz filter was implemented in 3D. Finally, the reconstructed image in Figure 4.13e is similar to that in Figure 4.13c except that a 3D model of the collimator–detector
are provided below for selected arteries. Nearly all the vessels above normally show some flow reversal during early diastole. A value of the pulsatility index of 5 or more in a limb artery is considered to be normal. 5.3.2 Velocity Estimation Techniques Prior to the basic overview of theoretical approaches to target velocity estimation, it is necessary to understand a few basic features of the received signal from blood scatterers. It is the statistical correlation of the received signal in