title: Radiation dose optimisation in dynamic volume CT of the heart: tube current adaptation based on anterior-posterior chest diameter.
abstract: To compare tube current adaptation based on 3 body mass index (BMI) categories versus anterior-posterior chest diameter (APD) for radiation dose optimisation in patients undergoing dynamic volume cardiac CT. Two cardiac imaging centres participated in the study. 20 patients underwent a prospectively triggered 320-slice single beat cardiac CT using the X-ray tube current [mA] manually adjusted to the patient's BMI (group I). In 20 subsequent patients, the tube current was adapted according to the patient's APD (group II). All other parameters were kept constant. Image noise was defined as the standard deviation of attenuation values and measured using a ROI in the descending aorta. Variation in image noise was statistically compared between both patient groups. Average and standard deviation of pixel noise were 29.1 HU and 14.8 HU in group I and 28.0 HU and 4.2 HU in group II. Inter-individual variation of pixel noise was significantly lower in group II compared to group I (p < 0.0001). Tube current adaptation based on APD is superior to stepwise adaptation based on BMI for optimising radiation dose in dynamic volume cardiac CT and therefore limits unnecessary radiation dose while ensuring diagnostic image quality in patients with diverse body habitus.
authors.affiliation: Department of Medical Imaging, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Patrik
authors.initials: P
authors.lastname: Rogalla
authors.forename: Jörg
authors.initials: J
authors.lastname: Blobel
authors.forename: Sonja
authors.initials: S
authors.lastname: Kandel
authors.forename: Henning
authors.initials: H
authors.lastname: Meyer
authors.forename: Jürgen
authors.initials: J
authors.lastname: Mews
authors.forename: Christian
authors.initials: C
authors.lastname: Kloeters
authors.forename: Hany
authors.initials: H
authors.lastname: Kashani
authors.forename: Alexander
authors.initials: A
authors.lastname: Lembcke
authors.forename: Narinder
authors.initials: N
authors.lastname: Paul
mesh_terms: D016477:Artifacts; D015992:Body Mass Index; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D005858:Germany; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009864:Ontario; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011829:Radiation Dosage; D015203:Reproducibility of Results; D013909:Thorax / Q000033:anatomy & histology*; D014057:Tomography, X-Ray Computed