s e t s n mage-guided radiation therapy (IGRT) is currently an merging technology and is undergoing rapid transormation. There have been different interpretations of his technology. Medical Dosimetry journal has deoted 4 special volumes on this topic. With the recent evelopment in positron emission tomography (PET), n particular, the commercial availability of PET-CT ybrid scanner, the advancem...

The purpose of this manuscript is to provide a tutorial overview on the subject of cone-beam geometry devices imaging. Toward this end, we have tried to strike a balance among purely algorithmic issues, topics (tomosynthesis imaging etc.) dealing with how to generate data for reconstruction in different domains, and artifacts inherent to different data collection strategies. This manuscript is ...

Themathematical principles of computed tomography (CT) were first investigated by J. Radon [28] as early as 1917 and were later extended to complex fields by Kirillov [22]. The first application of tomography was, surprisingly, in radio astronomy [2], and today, it finds usage in diverse fields such as medical imaging, seismology, and underwater acoustic imaging. In medical imaging, CT has had ...

PURPOSE The present study was performed to compare the planning of implant placement based on panoramic radiography (PAN) and cone-beam computed tomography (CBCT) images, and to study the impact of the image dataset on the treatment planning. MATERIALS AND METHODS One hundred five partially edentulous patients (77 males, 28 females, mean age: 46 years, range: 26-67 years) seeking oral implant...

In this paper, we perform numerical studies on Feldkamp-type and Katsevich-type algorithms for cone-beam reconstruction with a nonstandard spiral locus to develop an electron-beam micro-CT scanner. Numerical results are obtained using both the approximate and exact algorithms in terms of image quality. It is observed that the two algorithms produce similar quality if the cone angle is not large...

Head motion during brain CT studies can adversely affect the reconstructed image through distortion and other artifacts such as blurring and doubling, thereby losing substantial information. In this paper, we propose a method to detect and eliminate motion artifacts in Feldkamp-David-Kress (FDK) based three-dimensional (3D) cone-beam tomography. Motion detection is achieved by comparing the cor...

To develop volumetric micro-CT fluoroscopy for small animal imaging, we have proposed a cone-beam system with multiple x-ray sources. In this paper, we extend Parker's single-source half-scan weighting scheme to the case of an odd number of x-ray sources that are equiangularly distributed, and apply it for half-scan Feldkamp-type reconstruction in this unique geometry. In the numerical simulati...

A major challenge in X-ray computed tomography (CT) is reducing radiation dose while maintaining high quality of reconstructed images. To reduce the radiation dose, one can reduce the number of projection views (sparse-view CT); however, it becomes difficult to achieve high quality image reconstruction as the number of projection views decreases. Researchers have applied the concept of learning...

Based on the fan-beam reconstruction formula recently developed by Noo et al. [Phys. Med. Biol. 47, 2525-2546 (2002)] we develop a Feldkamp-type algorithm for the reconstruction of a volume of interest (VOI) from super-short-scan data. With either a circular or spiral scanning locus in our VOI reconstruction scheme, we first estimate fan-beam data from cone-beam data using the popular "cosine c...