Skip to main content
Key Specialties
Cardiology Diabetology Endocrinology Gastroenterology Geriatrics and Gerontology Gynecology and Obstetrics Hematology Infectious Disease Internal Medicine Nephrology Neurology Oncology Pediatrics Respiratory Medicine Rheumatology Surgery
Congress Coverage
2024 ACC Congress 2023 ESMO Congress 2023 EASD Congress 2023 ERS Congress 2023 ESC Congress
Clinical Collections
Advances in Alzheimer’s

At a glance: The STEP trials

A round-up of the STEP phase 3 clinical trials evaluating semaglutide for weight loss in people with overweight or obesity.
ADVANCED SEARCH
Log in
Top
European Radiology
Published in: European Radiology 4/2015

01-04-2015 | Physics

Abdominal CT during pregnancy: a phantom study on the effect of patient centring on conceptus radiation dose and image quality

Authors: G. Solomou, A. E. Papadakis, J. Damilakis

Published in: European Radiology | Issue 4/2015

Login to get access

Abstract

Objectives

To investigate the effect of patient centring on conceptus radiation dose and image quality in abdominal CT during pregnancy.

Material and methods

Three anthropomorphic phantoms that represent a pregnant woman at the three trimesters of gestation were subjected to a routine abdominal CT. Examinations were performed with fixed mAs (mAsf) and with the automatic exposure control system (AEC) activated. The percent reduction between mAsf and modulated mAs (mAsmod) was calculated. Conceptus dose (Dc) was measured using thermoluminencent dosimeters. To study the effect of misplacement of pregnant women on Dc, each phantom was positioned at various locations relative to gantry isocentre. Image quality was evaluated on the basis of image noise, signal-to-noise ratio, and contrast-to-noise ratio.

Results

The maximum reduction between mAsf and mAsmod was 59.8 %, while the corresponding DC reduction was 59.3 %. DC was found to decrease by up to 25 % and 7.9 % for phantom locations below and above the isocentre, respectively. Image quality deteriorated when AEC was activated, and it was progressively improved from lower to higher than the isocentre locations.

Conclusion

Centring errors do not result in an increase in Dc. To maintain image quality, accurate centring is required.

Key Points

• AEC activation reduces conceptus radiation dose at all gestational stages.
• Patients should be accurately aligned at the gantry isocenter.
• Patient centring deserves increased attention in clinical practice.
• Pregnant patient centring errors do not considerably affect conceptus dose.
Literature
1.
Kennedy A (2000) Assessment of acute abdominal pain in the pregnant patient. Semin Ultrasound CT MR 21:64–77CrossRefPubMed
2.
Wagner LK, Huda W (2004) When a pregnant woman with suspected appendicitis is referred for a CT scan, what should a radiologist do to minimize potential radiation risks? Pediatr Radiol 34:589–590CrossRefPubMed
3.
Goldman SM (2000) Overview of emergency radiological management of the pregnant patient, especially the traumatized pregnant patient. Emerg Radiol 7:198–205CrossRef
4.
5.
Shetty MK (2010) Abdominal computed tomography during pregnancy: a review of indications and fetal radiation exposure issues. Semin Ultrasound CT MR 3:3–7CrossRef
6.
Dauer LT, Thornton RH, Miller DL et al (2012) Radiation management for interventions using fluoroscopic or computed tomographic guidance during pregnancy: A joint guideline of the society of interventional radiology and the cardiovascular and interventional radiological society of Europe with endorsement by the Canadian interventional radiology association. J Vasc Interv Radiol 23:19–32CrossRefPubMed
7.
Damilakis J, Perisinakis K, Voloudaki A, Gourtsoyiannis N (2000) Estimation of fetal radiation dose from computed tomography scanning in late pregnancy. Depth-dose data from routine examinations. Invest Radiol 35:527–533CrossRefPubMed
8.
Damilakis J, Tzedakis A, Perisinakis K, Papadakis AE (2010) A method of estimating conceptus doses resulting from multidetector CT examinations during all stages of gestation. Med Phys 37:6411–6420CrossRefPubMed
9.
Damilakis J, Perisinakis K, Tzedakis A, Papadakis AE, Karantanas A (2010) Radiation dose from multidetector CT during early gestation: A method that allows for variations in maternal body size and conceptus position. Radiology 257:483–489CrossRefPubMed
10.
Goldberg-Stein SA, Liu B, Hahn PF, Lee SI (2012) Radiation dose management: part 2, estimating fetal radiation risk from CT during pregnancy. Am J Roentgenol 198(4):W352–W356CrossRef
11.
Gilet G, Dunkin JM, Fernandez TJ, Button TM, Budorick NE (2011) Fetal radiation dose during gestation estimated on an anthropomorphic phantom for three generations of CT scanners. Am J Roentgenol 196:1133–1137CrossRef
12.
Jaffe TA, Neville AM, Anderson-Evans C et al (2009) Early first trimester fetal dose estimation method in a multivendor study of 16- and 64-MDCT scanners and low-dose imaging protocols. Am J Roentgenol 193:1019–1024CrossRef
13.
Angel E, Wellnitz CV, Goodsitt MM et al (2008) Radiation dose to the conceptus for pregnant patients undergoing multidetector CT imaging: Monte Carlo simulations estimating fetal dose for a range of gestational age and patient size. Radiology 249:220–227CrossRefPubMedCentralPubMed
14.
Bredenholler C, Feuerlein U (2006) Somatom Sensation 16 Application Guide. Medical, Siemens
15.
Kalra M, Maher MM, Toth T et al (2004) Techniques and applications of automatic tube current modulation for CT. Radiology 233:649–657CrossRefPubMed
16.
Kalender W, Wolf H, Suess C (1999) Dose reduction in CT by anatomically adapted tube current modulation. II. Phantom measurements. Med Phys 26:2248–2253CrossRefPubMed
17.
McCollough C, Bruesewitz M, Kofler JM (2006) CT dose reduction and dose management tools: Overview of available options. Radiographics 26:503–512CrossRefPubMed
18.
Greess H, Wolf H, Baum U et al (2000) Dose reduction in computed tomography by attenuation-based on-line modulation of tube current: evaluation of six anatomical regions. Eur Radiol 10:391–394CrossRefPubMed
19.
Gies M, Kalender WA, Wolf H, Suess C (1999) Dose reduction in CT by anatomically adapted tube current modulation. I. Simulation studies. Med Phys 26:2235–2247CrossRefPubMed
20.
Papadakis AE, Perisinakis K, Damilakis J (2008) Automatic exposure control in pediatric and adult multidetector CT examinations: a phantom study on dose reduction. Med Phys 35:4567–4576CrossRefPubMed
21.
van Straten M, Deak P, Shrimpton P, Kalender W (2009) The effect of angular and longitudinal tube current modulations on the estimation of organ and effective doses in x-ray computed tomography. Med Phys 36:4881–4889CrossRefPubMed
22.
Matsubara K, Koshida K, Suzuki M, Tsujii H, Matsui O (2008) Comparison between 3-D and z-axis automatic tube current modulation technique in multidetector row CT. Radiat Prot Dosimetry 128:106–111CrossRefPubMed
23.
Namasivayam S, Kalra MK, Pottala KM, Waldrop SM, Hudqins PA (2006) Optimization of z-axis automatic exposure control for multidetector row CT evaluation of neck and comparison with fixed tube current technique for image quality and radiation dose. Am J Neuroradiol 27:2221–2225PubMed
24.
Kalra MK, Maher MM, Kamath RS et al (2004) Sixteen- detector row CT of abdomen and pelvis: study for optimization of z-axis modulation technique performed in 153 patients. Radiology 233:241–249CrossRefPubMed
25.
Karla MK, Toth TL (2012) Patient centering in MDCT: Dose effects. In: Tack D et al (eds) Radiation dose from multidetector CT. Springer-Verlag, Berlin, pp 273–278
26.
Toth TL, Zhanyu GE, Daly MP (2007) The influence of patient centering on CT dose and image noise. Med Phys 34:3093–3101CrossRefPubMed
27.
Perisinakis K, Seimenis I, Tzedakis A, Papadakis AE, Damilakis J (2013) The effect of head size/shape, miscentering and bowtie filter on peak patient tissue doses from modern brain perfusion 256-slice CT: how can we minimize the risk for deterministic effects? Med Phys 40(1):011911CrossRefPubMed
28.
Li J, Udayasankar U, Toth TL, Small WC, Karla MK (2008) Application of automatic vertical positioning software to reduce radiation exposure in multidetector row computed tomography of the chest. Invest Radiol 43:447–452CrossRefPubMed
29.
Matsubara K, Koshida K, Ichikawa K et al (2009) Misoperation of CT automatic tube current modulation systems with inappropriate patient centering: Phantom studies. Am J Roentgenol 192:862–865CrossRef
30.
Papadakis AE, Perisinakis K, Damilakis J (2014) Automatic exposure control in CT: the effect of patient size, anatomical region and prescribed modulation strength on tube current and image quality. Eur Radiol 24:2520–2531CrossRefPubMed
31.
Papadakis AE, Perisinakis K, Oikonomou I, Damilakis J (2011) Automatic exposure control in pediatric and adult computed tomography examinations: can we estimate organ and effective dose from mean mAs reduction? Invest Radiol 46:654–662CrossRefPubMed
32.
Papadakis AE, Perisinakis K, Damilakis J (2007) Angular on-line tube current modulation in multidetector CT examinations of children and adults: the influence of different scanning parameters on dose reduction. Med Phys 34:2867–2874CrossRef
Metadata
Title
Abdominal CT during pregnancy: a phantom study on the effect of patient centring on conceptus radiation dose and image quality
Authors
G. Solomou
A. E. Papadakis
J. Damilakis
Publication date
01-04-2015
Publisher
Springer Berlin Heidelberg
Published in
European Radiology / Issue 4/2015
Print ISSN: 0938-7994
Electronic ISSN: 1432-1084
DOI
https://doi.org/10.1007/s00330-014-3505-2

Other articles of this Issue 4/2015

European Radiology 4/2015 Go to the issue

Breast

A 16-channel MR coil for simultaneous PET/MR imaging in breast cancer

Hepatobiliary-Pancreas

The diagnostic value of Gd-EOB-DTPA-MRI for the diagnosis of focal nodular hyperplasia: a systematic review and meta-analysis

Musculoskeletal

Characterization of the collagen component of cartilage repair tissue of the talus with quantitative MRI: comparison of T2 relaxation time measurements with a diffusion-weighted double-echo steady-state sequence (dwDESS)

Interventional

Radiofrequency ablation of chondroblastoma: long-term clinical and imaging outcomes

Musculoskeletal

Diagnostic performance of CT-arthrography and 1.5T MR-arthrography for the assessment of glenohumeral joint cartilage: a comparative study with arthroscopic correlation

Gastrointestinal

Disadvantages of using the area under the receiver operating characteristic curve to assess imaging tests: A discussion and proposal for an alternative approach