Relationships of Radiation Dose Indices with Body Size Indices in Adult Body Computed Tomography.

We investigated the relationships between radiation dose indices and body size indices in adult body computed tomography (CT). A total of 3200 CT scans of the thoracic, abdominal, abdominopelvic, or thoraco-abdominopelvic regions performed using one of four CT scanners were analyzed. Volume CT dose index (CTDIvol) and dose length product (DLP) were compared with various body size indices derived from CT images (water-equivalent diameter, WED; effective diameter, ED) and physical measurements (weight, weight/height, body mass index, and body surface area).

Factors affecting dose-length product of computed tomography component in whole-body positron emission tomography/computed tomography.

In whole-body positron emission tomography (PET)/computed tomography (CT), it is important to optimise the CT radiation dose. We have investigated factors affecting the dose-length product (DLP) of the CT component of whole-body PET/CT and derived equations to predict the DLP. In this retrospective study, 1596 whole-body oncology PET/CT examinations withF-fluorodeoxyglucose were analysed.

Conversion from dose length product to effective dose for the CT component of whole-body PET/CT.

Objective: For dose management of CT, the ratio of effective dose (ED) to dose length product (DLP) is often used to convert DLP to ED. We evaluated this ratio in the CT component of whole-body PET/CT performed under various imaging conditions to determine a practical method for ED estimation applicable to PET/CT.

Methods: In total, 400 patients who underwent whole-body PET/CT were enrolled.

Conversion from dose-length product to effective dose in computed tomography venography of the lower extremities.

For radiation dose assessment of computed tomography (CT), effective dose (ED) is often estimated by multiplying the dose-length product (DLP), provided automatically by the CT scanner, by a conversion factor. We investigated such conversion in CT venography of the lower extremities performed in conjunction with CT pulmonary angiography. The study subjects consisted of eight groups imaged using different scanners and different imaging conditions (five and three groups for the GE and Siemens scanners, respectively).

SUBOPTIMAL MODULATION OF RADIATION DOSE IN THE COMPUTED TOMOGRAPHY COMPONENT OF WHOLE-BODY POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY.

Radiation exposure in computed tomography (CT) is automatically modulated by automatic exposure control (AEC) mainly based on scout images. To simulate the whole-body positron emission tomography/CT, CT images of a phantom were obtained using the posteroanterior scout image alone (PA scout) or the posteroanterior and lateral images (PA + Lat scout). Old and new versions of the AEC software were compared.

ESTIMATION OF RADIATION DOSE IN CT VENOGRAPHY OF THE LOWER EXTREMITIES: PHANTOM EXPERIMENTS USING DIFFERENT AUTOMATIC EXPOSURE CONTROL SETTINGS AND SCAN RANGES.

We performed phantom experiments to assess radiation dose in computed tomography (CT) venography of the lower extremities. CT images of a whole-body phantom were acquired using different automatic exposure control settings and scan ranges, simulating CT venography. Tube current decreased in the lower extremities compared to the trunk.

EFFECTS OF THE SCAN RANGE ON RADIATION DOSE IN THE COMPUTED TOMOGRAPHY COMPONENT OF ONCOLOGY POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY.

We performed phantom experiments to investigate radiation dose in the computed tomography component of oncology positron emission tomography/computed tomography in relation to the scan range. Computed tomography images of an anthropomorphic whole-body phantom were obtained from the head top to the feet, from the head top to the proximal thigh or from the skull base to the proximal thigh. Automatic exposure control using the posteroanterior and lateral scout images offered reasonable tube current modulation corresponding to the body thickness.

Clinical evaluation of CT radiation dose in whole-body F-FDG PET/CT in relation to scout imaging direction and arm position.

Objective: Radiation exposure in CT is modulated by automatic exposure control (AEC) mainly based on scout images. We evaluated CT radiation dose in whole-body PET/CT in relation to scout imaging direction and arm position, and investigated the behavior of AEC.

Methods: Eighty adult patients who underwent whole-body F-FDG PET/CT were divided into groups A, B, C, and D.

CT dose modulation using automatic exposure control in whole-body PET/CT: effects of scout imaging direction and arm positioning.

Automatic exposure control (AEC) modulates tube current and consequently X-ray exposure in CT. We investigated the behavior of AEC systems in whole-body PET/CT. CT images of a whole-body phantom were acquired using AEC on two scanners from different manufactures.

MONITORING DOSE-LENGTH PRODUCT IN COMPUTED TOMOGRAPHY OF THE CHEST CONSIDERING SEX AND BODY WEIGHT.

Dose-length product (DLP) is widely used as an indicator of the radiation dose in computed tomography. The aim of this study was to investigate the significance of sex and body weight in DLP-based monitoring of the radiation dose. Eight hundred computed tomographies of the chest performed using four different scanners were analysed.

Methods of CT Dose Estimation in Whole-Body ¹⁸F-FDG PET/CT.

Unlabelled: We evaluated the effective dose (ED) of the CT component of whole-body PET/CT using software dedicated to CT dose estimation and from dose-length product (DLP) values to establish practical methods of ED estimation.

Methods: Eighty adult patients who underwent (18)F-FDG whole-body PET/CT were divided into groups A and B, each consisting of 20 men and 20 women. In group A, ED of the CT component was calculated using CT-Expo for 6 anatomic regions separately, and whole-body ED was obtained by summing the regional EDs (CT-Expo method).