BACKGROUND Since tumors located in thorax region of body mainly move due to respiration, in the modern radiotherapy, there have been many attempts such as; external markers, strain gage and spirometer represent for monitoring patients' breathing signal. With the advent of fluoroscopy technique, indirect methods were proposed as an alternative approach to extract patients' breathing signals. M...

FDK algorithm is a well-known 3D (three-dimensional) approximate algorithm for CT (computed tomography) image reconstruction and is also known to suffer from considerable artifacts when the scanning cone angle is large. Recently, it has been improved by performing the ramp filtering along the tangential direction of the X-ray source helix for dealing with the large cone angle problem. In this p...

Motion artifact is still a major issue in cardiac computed tomography because the current motion correction and electrocardiogram gating techniques have not fully addressed this problem. The image quality can be significantly improved by using information about the actual state of the heart and an exact reconstruction algorithm. We propose to extend a cardiac computed tomographic technique, usi...

The aim of this work was to verify the indicated maximum entrance surface air kerma (ESAK) using a GE Innova IGS 520 imaging system during cardiac interventional procedures. Gafchromic XR RV3 films were used for the patient measurements to monitor the maximum ESAK. The films were scanned and calibrated to measure maximum ESAK. Thermoluminescent dosemeters were used to measure the backscatter fa...

We investigate helical cone-beam reconstruction using differentiated backprojection on π-lines and a subsequent inverse Hilbert transform. We report in particular on an implementation scheme that allows efficient reconstruction in the geometry of current Multi-Slice-CT scanners. This scheme is based on reconstruction on “theoretical” π-lines (π-lines that would have been measured in a continuou...

The state-of-the art for solving the nonlinear material decomposition problem in spectral computed tomography is based on variational methods, but these are computationally slow and critically depend particular choice of regularization functional. Convolutional neural networks have been proposed addressing issues. However, learning algorithms require large amounts experimental data sets. We pro...

The Livermore Torso Phantom, the consensus calibration phantom for measuring internally deposited radioactive materials in the lungs, liver and tracheo-bronchial lymph nodes, has been modified for calibrating direct, in vivo measurements of Am in the axillary lymph nodes. The axillary lymph nodes may contain radioactive material mobilized from a wound in a finger or hand which may confound resu...