Effects of different levels of CT iterative reconstruction on low-contrast detectability and radiation dose in patients of different sizes: an anthropomorphic phantom study.

Purpose: The purpose of this study was to verify the maintenance of low-contrast detectability at different CT dose reduction levels, in patients of different sizes, as a consequence of the application of iterative reconstruction at different strengths combined with tube current modulation.

Methods: Anthropomorphic abdominal phantoms of two sizes (small and large) were imaged at a fixed noise with iterative algorithm ASIR-V percentages in the range between 0 and 70% and corresponding dose reductions in the range of 0-83%. A total of 1400 images with and without liver low-contrast simulated lesions were evaluated by five radiologists, using the receiver operating characteristics (ROC) paradigm and evaluating the area under the ROC curve (AUC).

Radiation dose during endovascular aneurysm repair (EVAR): upgrade of an angiographic system from standard to Eco mode.

Purpose: To evaluate the radiation dose reduction during endovascular aneurysm repair (EVAR) after the reconfiguration of a Philips AlluraXper FD20 X-ray system.

Methods: Between 2013 and 2015, we implemented a low-dose protocol (Eco dose) increasing the filtration with 1 mm of Al and 0.1 of Cu on both fluoroscopy and fluorography and halving the frames per second in fluoroscopy.

Evaluation of a commercial automatic treatment planning system for liver stereotactic body radiation therapy treatments.

Purpose: Automated treatment planning is a new frontier in radiotherapy. The Auto-Planning module of the Pinnacle treatment planning system (TPS) was evaluated for liver stereotactic body radiation therapy treatments.

Methods: Ten cases were included in the study.

Adaptive Statistical Iterative Reconstruction-V Versus Adaptive Statistical Iterative Reconstruction: Impact on Dose Reduction and Image Quality in Body Computed Tomography.

Objective: The aim of this study was to evaluate the impact on dose reduction and image quality of the new iterative reconstruction technique: adaptive statistical iterative reconstruction (ASIR-V).

Methods: Fifty consecutive oncologic patients acted as case controls undergoing during their follow-up a computed tomography scan both with ASIR and ASIR-V. Each study was analyzed in a double-blinded fashion by 2 radiologists.

Calculation of tumour and normal tissue biological effective dose in Y liver radioembolization with different dosimetric methods.

Purpose: Radioembolization with Y microspheres is an effective treatment for unresectable liver tumours. Two types of microspheres are available: resin (SIR-Spheres®) and glass (Theraspheres®). The aim of this study is to compare biological effective dose (BED) values obtained with three different dosimetric methods.

Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT.

Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined.

Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using pcxmc software (pcxmc 2.

Aortic CT angiography dose reduction: investigation of optimal noise index and iterative algorithm strength in combination with low kV.

Objective: The purpose of this study was to optimize an aorta angiographic CT protocol, by investigating the best combination of tube current modulation, iterative algorithm strength and kV reduction.

Materials And Methods: Anthropomorphic phantoms of three sizes were imaged by CT with different values of noise index, of iterative algorithm ASIR percentages and kV in the range 80-120. Quantitative noise and contrast noise ratios were evaluated at different phantom locations.

A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging.

Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing.

Digital chest radiography system with amorphous selenium flat-panel detectors: Qualitative and dosimetric comparison with a dedicated film-screen system.

Purpose: To compare the quality and radiation dose of a conventional film-screen system and a digital system with amorphous selenium detectors in the study of the chest, by verifying overall performance and exposure levels for the main chest structures in patients of different sizes.

Materials And Methods: An analogic system (Chest-Changer, Dupont, Day-light model 1000) and a digital system (Directray Rad 1000C, Hologic) were tested on a total of 1000 patients randomly assigned to one of two groups of 500 subjects. The patients were further subdivided according to BMI (Body Mass Index).

Prostate brachytherapy with iodine-125 seeds: radiation protection issues.

Aims And Background: Brachytherapy for prostate cancer by means of permanently implanted 125I sources is a well established procedure. An increasing number of patients all over the world are treated with this modality. When the technique was introduced at our institution, radiation protection issues relative to this technique were investigated in order to comply with international recommendations and national regulations.

Patient dose evaluation and optimization of uropoietic multiphasic multislice CT examination.

Purpose: The aim of this study was to optimize acquisition data during multislice multiphasic CT examination of the renal excretory system in order to reduce patient effective dose without deterioration of the imaging quality.

Materials And Methods: With the aid of two dedicated software programmes we evaluated the patient effective dose during both multislice multiphasic CT examination of the renal excretory system and excretory urography. With the CT acquisition protocol, images of a test object (Helical CT phantom, CIRS) were examined by two expert radiologists to assess the number of visible inserted test images.