Standing CT of the equine head: Reducing radiation dose maintains image quality.
ALARA
CT
mAs
radiation safety
Journal
Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association
ISSN: 1740-8261
Titre abrégé: Vet Radiol Ultrasound
Pays: England
ID NLM: 9209635
Informations de publication
Date de publication:
Mar 2020
Mar 2020
Historique:
received:
12
07
2019
revised:
26
08
2019
accepted:
07
09
2019
pubmed:
12
12
2019
medline:
2
9
2020
entrez:
12
12
2019
Statut:
ppublish
Résumé
Multiple published studies involving computed tomographic (CT) examinations of the equine head utilise a wide range of mAs parameters for image acquisition. This prospective, experimental study assessed the effects of lowering mAs during CT image acquisition on image quality and scatter radiation on 10 cadaver equine heads. Each head was scanned three times at 300, 225, and 150 mAs, with all other scanning parameters remaining constant between series. An anthropomorphic phantom was positioned adjacent to each equine head during image acquisition, mimicking a human bystander, with an ionization chamber attached to the phantom at eye level. Each series was reconstructed using filtered back projection, using medium (H30) and high (H80) frequency reconstruction algorithms. Quantitative image quality assessment was performed by calculating signal to noise ratio (SNR) and contrast to noise ratio (CNR). Two qualitative image quality assessments were performed independently by three blinded board certified veterinary radiologists with a 4 week interval, using a visual grade analysis model adapted from peer reviewed medical literature. Ionization chamber measurements, calculated volume CT dose index (CTDIvol), and dose-length product (DLP) were recorded. Halving radiation dose during image acquisition from 300 to 150mAs resulted in comparable image quality between series. There was a statistically significant and linear relationship between mAs and scatter radiation to the bystander; halving mAs during image acquisition resulted in halving of scatter radiation. Results of this cadaveric study support the use of lower mAs settings during standing CT examinations of the equine head.
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
137-146Informations de copyright
© 2019 American College of Veterinary Radiology.
Références
Tucker RL, Farrell E. Computed tomography and magnetic resonance imaging of the equine head. Vet Clin North Am Equine Pract. 2001;17:131-144.
Manso-Díaz G, García-López J, Maranda L, Taeymans O. The role of head computed tomography in equine practice. Equine Vet Educ. 2015;27:136-145.
Huggons NA, Bell RJ, Puchalski SM. Radiography and computed tomography in the diagnosis of nonneoplastic equine mandibular disease. Vet Radiol Ultrasound. 2011;52:53-60.
BAR-AM Y, Pollard RE, Kass PH, Verstraete FJ. The diagnostic yield of conventional radiographs and computed tomography in dogs and cats with maxillofacial trauma. Vet Surg. 2008;37:294-299.
Liuti T, Smith S, Dixon PM. A comparison of computed tomographic, radiographic, gross and histological, dental, and alveolar findings in 30 abnormal cheek teeth from equine cadavers. Front Vet Sci. 2018;4:236.
Cissell DD, Wisner ER, Textor J, Mohr FC, Scrivani PV, Theon AP. Computed tomographic appearance of equine sinonasal neoplasia. Vet Radiol Ultrasound. 2012;53:245-251.
Kraft SL, Gavin P. Physical principles and technical considerations for equine computed tomography and magnetic resonance imaging. Vet Clin North Am Equine Pract. 2001;17:115-130. vii.
Liuti T, Reardon R, Dixon PM. Computed tomographic assessment of equine maxillary cheek teeth anatomical relationships, and paranasal sinus volumes. Vet Rec. 2017;181:452-452.
Solano M, Brawer RS. CT of the equine head: Technical considerations, anatomical guide, and selected diseases. Clin Techn Equine Pract. 2004;3:374-388.
Dakin S, Lam R, Rees E, Mumby C, West C, Weller R. Technical set-up and radiation exposure for standing computed tomography of the equine head. Equine Vet Educ. 2014;26:208-215.
Porter EG, Werpy NM. New concepts in standing advanced diagnostic equine imaging. Vet Clin Equine Prac. 2014;30:239-268.
Pease A, Mair T, Spriet M. Imaging the equine head and spine. Equine Vet J. 2017;49:13-14.
Wylie JD, Jenkins PA, Beckmann JT, Peters CL, Aoki SK, Maak TG. Computed tomography scans in patients with young adult hip pain carry a lifetime risk of malignancy. Arthroscopy. 2018;34:155-163. e153.
Brenner DJ, Elliston CD, Hall EJ, Berdon WE. Estimated risks of radiation-induced fatal cancer from pediatric CT. Am J Roentgenol. 2001;176:289-296.
Sodickson A, Baeyens PF, Andriole KP, et al. Recurrent CT, cumulative radiation exposure, and associated radiation-induced cancer risks from CT of adults. Radiology. 2009;251:175-184.
Pearce MS, Salotti JA, Little MP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. Lancet North Am Ed. 2012;380:499-505.
Krille L, Zeeb H, Jahnen A, et al. Computed tomographies and cancer risk in children: A literature overview of CT practices, risk estimations and an epidemiologic cohort study proposal. Radiat Environ Biophys. 2012;51:103-111.
Mayo-Smith WW, Hara AK, Mahesh M, Sahani DV, Pavlicek W. How I do it: managing radiation dose in CT. Radiology. 2014;273:657-672.
Zielinski J, Garner M, Band P, et al. Health outcomes of low-dose ionizing radiation exposure among medical workers: A cohort study of the Canadian national dose registry of radiation workers. Int J Occup Med Environ Health. 2009;22:149-156.
Mathews JD, Forsythe AV, Brady Z, et al. Cancer risk in 680 000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. BMJ. 2013;346:f2360.
Padole A, Ali Khawaja RD, Kalra MK, Singh S. CT radiation dose and iterative reconstruction techniques. Am J Roentgenol. 2015;204:W384-W392.
Ciraj-Bjelac O, Rehani MM, Sim KH, Liew HB, Vano E, Kleiman NJ. Risk for radiation-induced cataract for staff in interventional cardiology: is there reason for concern?. Catheter Cardiovasc Interv. 2010;76:826-834.
Kalra MK, Woisetschläger M, Dahlström N, et al. Radiation dose reduction with sinogram affirmed iterative reconstruction technique for abdominal computed tomography. J Comput Assist Tomogr. 2012;36:339-346.
Liuti T, Reardon R, Smith S, Dixon P. An anatomical study of the dorsal and ventral nasal conchal bullae in normal horses: Computed tomographic anatomical and morphometric findings. Equine Vet J. 2016;48:749-755.
Tucker R, Windley ZE, Abernethy AD, et al. Radiographic, CT and surgical anatomy of the equine sphenopalatine sinus in normal and diseased horses. Equine Vet J. 2016;48:578-584.
Korn A, Bender B, Fenchel M, et al. Sinogram affirmed iterative reconstruction in head CT: Improvement of objective and subjective image quality with concomitant radiation dose reduction. Eur J Radiol. 2013;82:1431-1435.
Rivers-Bowerman MD, Shankar JJS. Iterative reconstruction for head CT: effects on radiation dose and image quality. Can J Neurol Sci. 2014;41:620-625.
Ono S, Niwa T, Yanagimachi N, et al. Improved image quality of helical computed tomography of the head in children by iterative reconstruction. J Neuroradiol. 2016;43:31-36.
Corcuera-Solano I, Doshi A, Noor A, Tanenbaum L. Repeated head CT in the neurosurgical intensive care unit: feasibility of sinogram-affirmed iterative reconstruction-based ultra-low-dose CT for surveillance. Am J Neuroradiol. 2014;35:1281-1287.
OECD. Society at a Glance 2009. Paris, France: OECD; 2009.
Schulze D, Heiland M, Thurmann H, Adam G. Radiation exposure during midfacial imaging using 4- and 16-slice computed tomography, cone beam computed tomography systems and conventional radiography. Dentomaxillofac Radiol. 2004;33:83-86.
RPI. Code of Practice for Radiation Protection in Veterinary Medicine. Dublin, Ireland: Radiological Protection Institute of Ireland; 2002.
D'août C, Nisolle J-F, Navez M, et al. Computed tomography and magnetic resonance anatomy of the normal orbit and eye of the horse. Anat Histol Embryol. 2015;44:370-377.
Bushberg JT. The Essential Physics of Medical Imaging. Philadelphia, PA: Wolters Kluwer Health; 2012.
Vano E, Kleiman NJ, Duran A, Rehani MM, Echeverri D, Cabrera M. Radiation cataract risk in interventional cardiology personnel. Radiat Res. 2010;174:490-495.
ICRP. Statement on Tissue Reactions. Ontario, Canada: International Commission on Radiological Protection; 2011.
HERCA. Guidelines on Radiation Protection Education and Training of Veterinary Professionals. Montrouge, France: Heads of The European Radiological Protection Competent Authorities; 2017.
Diwakar M, Kumar M. A review on CT image noise and its denoising. Biomed Signal Process Control. 2018;42:73-88.
Solomon JB, Li X, Samei E. Relating noise to image quality indicators in CT examinations with tube current modulation. AJR Am J Roentgenol. 2013;200:592-600.
Korn A, Bender B, Fenchel M, et al. Sinogram affirmed iterative reconstruction in head CT: Improvement of objective and subjective image quality with concomitant radiation dose reduction. Eur J Radiol. 2013;82:1431-1435.
Ludewig E, Richter A, Frame M. Diagnostic imaging-evaluating image quality using visual grading characteristic (VGC) analysis. Vet Res Commun. 2010;34:473-479.
Frush DP, Donnelly LF, Rosen NS. Computed tomography and radiation risks: What pediatric health care providers should know. Pediatrics. 2003;112:951-957.
Carucci LR. Imaging obese patients: Problems and solutions. Abdom Imaging. 2013;38:630-646.
Figueira C, Di Maria S, Baptista M, Mendes M, Madeira P, Vaz P. Paediatric CT exposures: Comparison between CTDI vol and SSDE methods using measurements and Monte Carlo simulations. Radiat Prot Dosimetry. 2015;165:210-215.