Investigating centering, scan length, and arm position impact on radiation dose across 4 countries from 4 continents during pandemic: Mitigating key radioprotection issues

Intro : DSCT provides improved temporal resolution due to the simultaneous use of two x-ray sources & detectors. Although use of two sources may increase radiation, the DSCT offers key mechanisms to reduce dose (i.e. pitch adaptation, tube current modulation (TCM) & prospective triggering). Thus, our aim was to assess the patient radiation exposure associated with DSCT and identify variations based on the use of different scan related parameters. Methods : Prospective study of a single tertiary medical center where radiation and image quality related data was collected on 304 consecutive patients (pts) presenting for clinical CCT examination. Effective radiation dose was calculated by multiplying the dose-length product × (k=.017 mSv/mGy/cm). Image quality was rated on a subjective IQ score [1=poor to 4=excellent], as well as contrast (CNR) and signal-to-noise (SNR) ratios. Adjusted means of increased radiation dose were calculated based on linear regression models. Results: Among 304 consecutive studies (mean age 56.4, BMI 29.4 kg/m 2 , 37% Female), 60% were performed for coronary evaluation, 8% for CABG, 18% for pulmonary veins and 11% for aortic disease. The average radiation dose was 13.5±9.2mSv [range 0.5–55.5 mSv]. TABLE provides unadjusted and adjusted mean radiation dose for parameters which had a significant univariate association with radiation dose. Independent predictors of lower radiation included low kV, use of TCM, higher pitch, smaller scan length, and regular heart rhythm. Selected use of various TCM algorithms & low KV resulted in no significant difference in IQ, CNR, or SNR. Conclusions : DSCT is associated with a wide range of patient radiation exposure. The variability in dose is due to both controllable parameters (i.e. use of TCM, low kV, scan length) as well as parameters that cannot be altered (i.e. irregular rhythm). These results suggest that individualizing scan protocols may result in lower radiation dose without compromising image quality. Table: Cardiac DSCT Parameters Affecting Patient Radiation Dose

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Computed Tomography Pulmonary Angiography during Pregnancy: Radiation Dose of Commonly Used Protocols and the Effect of Scan Length Optimization

Korean Journal of Radiology ◽

10.3348/kjr.2017.0779 ◽

2019 ◽

Vol 20 (2) ◽

pp. 313 ◽

Cited By ~ 5

Author(s):

Babs M.F. Hendriks ◽

Roald S. Schnerr ◽

Gianluca Milanese ◽

Cécile R.L.P.N. Jeukens ◽

Sandra Niesen ◽

...

Keyword(s):

Computed Tomography ◽

Radiation Dose ◽

Pulmonary Angiography ◽

Computed Tomography Pulmonary Angiography ◽

Length Optimization ◽

Scan Length

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Assessment of radiation dose from abdominal quantitative CT with short scan length

British Journal of Radiology ◽

10.1259/bjr.20160931 ◽

2017 ◽

Vol 90 (1074) ◽

pp. 20160931 ◽

Cited By ~ 1

Author(s):

Xinhua Li ◽

Kai Yang ◽

Matthew C DeLorenzo ◽

Bob Liu

Keyword(s):

Radiation Dose ◽

Quantitative Ct ◽

Scan Length

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Study on Image Quality and Radiation Dose due to the Arm Position in the Abdomen/Pelvis CT

Journal of the Korean Society of Radiology ◽

10.7742/jksr.2015.9.6.337 ◽

2015 ◽

Vol 9 (6) ◽

pp. 337-342

Author(s):

Jongwoong Lee ◽

Doyeon Won ◽

Jaeeun Jung ◽

Hyeongyun Kim

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Arm Position

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Scan Length Adjustment of CT Coronary Angiography Using the Calcium Scoring Scan: Effect on Radiation Dose

American Journal of Roentgenology ◽

10.2214/ajr.09.2970 ◽

2010 ◽

Vol 194 (3) ◽

pp. W272-W277 ◽

Cited By ~ 34

Author(s):

Sebastian Leschka ◽

Chan-Hi Kim ◽

Stephan Baumueller ◽

Paul Stolzmann ◽

Hans Scheffel ◽

...

Keyword(s):

Radiation Dose ◽

Coronary Angiography ◽

Ct Coronary Angiography ◽

Calcium Scoring ◽

Scan Length

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A completed audit cycle of the lateral scan projection radiograph in CT pulmonary angiography (CTPA); the impact on scan length and radiation dose

Clinical Radiology ◽

10.1016/j.crad.2012.11.016 ◽

2013 ◽

Vol 68 (6) ◽

pp. 574-579 ◽

Cited By ~ 4

Author(s):

J.C.L. Rodrigues ◽

I.S. Negus ◽

N.E. Manghat ◽

M.C.K. Hamilton

Keyword(s):

Radiation Dose ◽

Pulmonary Angiography ◽

Ct Pulmonary Angiography ◽

Audit Cycle ◽

The Impact ◽

Scan Length

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Multi-detector computed tomography radiation doses in the follow-up of paediatric neurosurgery patients in KwaZulu-Natal: A dosimetric audit

South African Journal of Radiology ◽

10.4102/sajr.v18i1.588 ◽

2014 ◽

Vol 18 (1) ◽

Author(s):

Christopher T. Sikwila ◽

Khatija Amod ◽

Brindley D. Cupido ◽

Ali Sabri

Keyword(s):

Computed Tomography ◽

Radiation Dose ◽

Radiation Doses ◽

Current Time ◽

Paediatric Neurosurgery ◽

Radiology Reports ◽

Clinical Scenarios ◽

Multi Detector Computed Tomography ◽

Scan Length

Background: Multi-detector computed tomography (MDCT) is the preferred modality for follow-up of paediatric neurosurgery patients. Serial imaging, however, has the disadvantage of an ionising radiation burden, which may be mitigated using the ‘as low as reasonably achievable’ (ALARA) principle. Objectives: The primary objectives were to determine the radiation dose exposure in paediatric patients subjected to MDCT imaging following neurosurgery and to compare these values with references in current literature. Our secondary objective was to assess the relationship between radiation dose and clinical scenario.Method: Retrospective descriptive data were collected from all paediatric postsurgical patients (n = 169) between the ages of 0 and 12 years who had their first followed-up scan in the year 2010 and were followed up for six months or less. Dose-length product (DLP) and current-time product were collected from the picture archiving and communication system. Demographic data including radiology reports were collected from the hospital information system. The effective doses (ED) were calculated from the corresponding DLP using age-adjusted conversion factors. For purposes of comparison with other studies, median dosimetric values were calculated and the children were grouped into three age ranges, namely younger than 3 years, 3–7 years and 8–12 years old.Results: The highest median radiation doses were noted in patients being followed-up for intracranial abscesses (1183 mGy cm) in the 8–12 year age group, most of whom were female. The lowest radiation doses were for intracranial shunt follow-ups (447 mGy cm). Median values for DLP, ED and current-time product (mAs) were comparable to reference doses in all three age groups. However, our study showed a much broader distribution of values with higher upper limits relative to reference values. Indications for follow-up included shunts (n = 110; 65%), intracranial abscess (n = 31; 18%), subdural haematoma (n = 13; 8%) and tumour (n = 6; 4%). Head trauma only accounted for 5% of the cases.Conclusion: The median radiation doses measured were comparable to values in literature and therefore deemed acceptable. The wider dose distributions of all three dosimetric parameters (DLP, ED and mAs) were attributed to inappropriate use of scan length and reference effective mAs. Adherence to recommended scan length protocols should be encouraged. Evaluation of the current use of reference effective mAs is needed and will require a separate study to determine the smallest value that can be used without compromising image quality. Further dose reductions could be achieved by omission of unenhanced scans in the follow-up of intracranial abscesses. It is recommended that diagnostic reference levels specific to South African clinical scenarios be developed to make local dosimetric audits more relevant.

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