Image quality in CT thorax: effect of altering reconstruction algorithm and tube load.

Non-linear properties of iterative reconstruction (IR) algorithms can alter image texture. We evaluated the effect of a model-based IR algorithm (advanced modelled iterative reconstruction; ADMIRE) and dose on computed tomography thorax image quality. Dual-source scanner data were acquired at 20, 45 and 65 reference mAs in 20 patients.

Assessment of image quality in abdominal computed tomography: Effect of model-based iterative reconstruction, multi-planar reconstruction and slice thickness on potential dose reduction.

Purpose: To determine the effect of tube load, model-based iterative reconstruction (MBIR) strength and slice thickness in abdominal CT using visual comparison of multi-planar reconstruction images.

Method: Five image criteria were assessed independently by four radiologists on two data sets at 42- and 98-mAs tube loads for 25 patients examined on a 192-slice dual-source CT scanner. Effect of tube load, MBIR strength, slice thickness and potential dose reduction was estimated with Visual Grading Regression (VGR).

Image quality and pathology assessment in CT Urography: when is the low-dose series sufficient?

Background: Our aim was to compare CT images from native, nephrographic and excretory phases using image quality criteria as well as the detection of positive pathological findings in CT Urography, to explore if the radiation burden to the younger group of patients or patients with negative outcomes can be reduced.

Methods: This is a retrospective study of 40 patients who underwent a CT Urography examination on a 192-slice dual source scanner. Image quality was assessed for four specific renal image criteria from the European guidelines, together with pathological assessment in three categories: renal, other abdominal, and incidental findings without clinical significance.

Assessment of image quality in abdominal CT: potential dose reduction with model-based iterative reconstruction.

Purpose: To estimate potential dose reduction in abdominal CT by visually comparing images reconstructed with filtered back projection (FBP) and strengths of 3 and 5 of a specific MBIR.

Material And Methods: A dual-source scanner was used to obtain three data sets each for 50 recruited patients with 30, 70 and 100% tube loads (mean CTDI 1.9, 3.

IMPLICATIONS OF PATIENT CENTRING ON ORGAN DOSE IN COMPUTED TOMOGRAPHY.

Automatic exposure control (AEC) in computed tomography (CT) facilitates optimisation of dose absorbed by the patient. The use of AEC requires appropriate 'patient centring' within the gantry, since positioning the patient off-centre may affect both image quality and absorbed dose. The aim of this experimental study was to measure the variation in organ and abdominal surface dose during CT examinations of the head, neck/thorax and abdomen.

Efficient quality assurance programs in radiology and nuclear medicine in Ostergotland, Sweden.

Owners of imaging modalities using ionising radiation should have a documented quality assurance (QA) program, as well as methods to justify new radiological procedures to ensure safe operation and adequate clinical image quality. This includes having a system for correcting divergences, written imaging protocols, assessment of patient and staff absorbed doses and a documented education and training program. In this work, how some aspects on QA have been implemented in the County of Ostergötland in Sweden, and efforts to standardise and automate the process as an integrated part of the radiology and nuclear medicine QA programs were reviewed.

Automatic tube-current modulation in CT--a comparison between different solutions.

In this study, tube-current modulation systems on two different CT equipments have been evaluated: Care Dose from Siemens and Auto mA from GE Medical Systems. Care Dose modulates the tube current in the xy-plane during rotation whereas Auto mA modulates the tube current in the z-direction. xy-Plane modulation was investigated by using an elliptic Polymethylmethacrylate phantom and a CTDI-ion chamber.