We propose a novel method to reduce the noise in fan-beam computed tomography (CT) imaging. First, the inverse Radon transform is induced for a family of differential expression of projection function. Second, the diffusion partial differential equation (PDE) is generalized from image space to projection space in parallel-beam geometry. Third, the diffusion PDE is further induced from parallel-...

In current computed tomography (CT) examinations, the associated X-ray radiation dose is of significant concern to patients and operators, especially CT perfusion (CTP) imaging that has higher radiation dose due to its cine scanning technique. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) parameter as low as reasonably achievable in data...

introduction : one of the key factors in successful endodontic therapy is to adequately fill the root canals. the aim of this in vitro study was to compare the quality of four different root canal obturation techniques: cold lateral condensation (clc), warm vertical condensation (wvc), obtura ii (oii) and gutta flow (gf) by using micro-computed tomography (micro ct). materials and methods: a to...

TO CORRELATE DIFFERENT CT SYSTEM: MSCT (multislice computed tomography) with different acquisition parameters (100KV, 80KV), different reconstruction algorithm (ASIR) and CBCT (cone beam computed tomography) examination in terms of absorbed X-ray dose and diagnostic accuracy.80 KV protocols compared with 100 KV protocols resulted in reduced total radiation dose without relevant loss of diagnost...

OBJECTIVE This work aims to explore the effects of adaptive statistical iterative reconstruction (ASiR) and model-based iterative reconstruction (MBIR) algorithms in reducing computed tomography (CT) radiation dosages in abdominal imaging. METHODS CT scans on a standard male phantom were performed at different tube currents. Images at the different tube currents were reconstructed with the fi...

Kilovotage cone-beam computed tomography (kV-CBCT) has shown potentials to improve the accuracy of a patient setup in radiotherapy. However, daily and repeated use of CBCT will deliver high extra radiation doses to patients. One way to reduce the patient dose is to lower mAs when acquiring projection data. This, however, degrades the quality of low mAs CBCT images dramatically due to excessive ...

BACKGROUND To study dose reduction using iterative reconstruction (IR) for pediatric great vessel stent computed tomography (CT). METHODS Five different great vessel stents were separately placed in a gel-containing plastic holder within an anthropomorphic chest phantom. The stent lumen was filled with diluted contrast gel. CT acquisitions were performed at routine dose, 52% and 81% reduced d...

OBJECTIVE Several studies have been published regarding the use of bismuth shielding to protect the breast in computed tomography (CT) scans and, up to the writing of this article, only one publication about barium shielding was found. The present study was aimed at characterizing, for the first time, a lead breast shielding. MATERIALS AND METHODS The percentage dose reduction and the influen...

We introduce a value-based noise reduction method for Dual-Energy CT applications. It is based on joint intensity statistics estimated from high- and low-energy CT scans of the identical anatomy in order to reduce the noise level in both scans. For a given pair of measurement values, a local gradient ascension algorithm in the probability space is used to provide a noise reduced estimate. As a ...