radiation therapy is considered as one of the main methods in cancer treatment. in this method, determination of exact location and geometric properties of tumor is necessary for treatment planning that leads to increased accuracy and output of treatment and reduction of healthy tissue dose. for this purpose, the aim of the present study has been physiological transmission of gallium as a pharm...

In the last decades, treatment planning for multicatheter interstitial breast brachytherapy has evolved considerably from fluoroscopy-based 2D to anatomy-based 3D planning. To plan the right positions of the catheters, ultrasound or computed tomography (CT) imaging can be used, but the treatment plan is always based on postimplant CT images. With CT imaging, the 3D target volume can be defined ...

Particle beam treatment allows accurate dose delivery onto carcinogen tissue. The reachable accuracy is limited by patient alignment errors relative to the beam source. Errors can be corrected manually or by automatic comparison of two X-ray images to a CT-scan but correction mostly does not cover all degrees of freedom (DoF). In this contribution we present a solution that makes use of one X-r...

OBJECTIVES To assess the effect of a change in skull x ray policy on the rate of admission, use of computed tomography (CT), radiation dose per head injury, and detection of intracranial injuries; and to compare the characteristics of patients with normal and abnormal head CT. DESIGN Retrospective cohort study. SETTING UK paediatric teaching hospital emergency department. PATIENTS 1535 pa...

The introduction in 1998 of multi-detector row computed tomography (CT) by the major CT vendors was a milestone with regard to increased scan speed, improved z-axis spatial resolution, and better utilization of the available x-ray power. In this review, the general technical principles of multi-detector row CT are reviewed as they apply to the established four- and eight-section systems, the mo...

Computed tomography (CT) is a well stablished imaging technique that is used worldwide for diagnosis and treatment planning. The purpose of this review is to describe the most notable technological advances in the last decade, with a special focus on their impact in CT dose optimization, that is, achieving the same diagnostic image quality at a reduced radiation dose. The review describes main ...

Recently, we accelerated ordered subsets (OS) methods for low-dose X-ray CT image reconstruction using momentum techniques, particularly focusing on Nesterov’s momentum method. This paper develops an “optimized” momentum method that is faster than Nesterov’s method. Drori and Teboulle’s original version requires substantial memory space and computation time per iteration. Therefore, we design a...

Statistical image reconstruction (SIR) methods have shown potential to substantially improve the image quality of low-dose X-ray computed tomography (CT) as compared to the conventional filtered back-projection (FBP) method. According to the maximum a posterior (MAP) estimation, the SIR methods can be typically formulated by an objective function consisting of two terms: (1) data-fidelity (or e...

The CT scanners on the market offer a multitude of procedure protocols that enable many clinical questions to be answered quickly. CT scanners can be used to image all parts of the body, some common uses in our hospital include; acute inflammatory bowel diseases; acute appendicitis, trauma including head, spine and skeletal trauma, renal diseases including congenital, inflammatory and neoplasti...

The purpose of this study was to show that the nominal peak tube voltage potential (kVp) and measured half-value layer (HVL) can be used to generate energy spectra and fluence profiles for characterizing a computed tomography (CT) X-ray source, and to validate the source model and an in-house kV X-ray dose computation algorithm (kVDoseCalc) for computing machine- and patient-specific CT dose. S...