Skip to main content
NCBI home page
The British Journal of Radiology logoLink to The British Journal of Radiology
. 2021 Nov 29;95(1129):20210269. doi: 10.1259/bjr.20210269

The use of digital magnification to reduce radiation dose in the cardiac catheter laboratory

Shailesh Dalvi 1, Hywel Mortimer Roberts 1, Christopher Bellamy 1, Michael Rees 1,2,✉
PMCID: PMC8722255  PMID: 34889648

Abstract

Objectives:

To audit whether using magnification of images by use of a large viewing screen using digital matrix magnification which enlarges the image by 33% without using the X-ray machine zoom magnification protocols on a Siemens Artis Zee X-ray machine in a cardiac catheter laboratory results in a reduction of kerma–area product (KAP) for both diagnostic and interventional procedures. This reduction was predicted in an in vitro study in our laboratory, which has previously shown a 20.4% reduction in KAP.

Methods:

A retrospective analysis was conducted of the radiation exposure to compare the measured KAP recorded during the period when conventional magnification with automatic brightness and dose control was used on a Siemens Artis Zee X-ray machine with a flat panel detector and when magnification settings were avoided by using a large screen to enlarge and project a non-magnified image by digital magnification. The analysis was carried out for patients having a diagnostic coronary angiogram and those having an interventional coronary procedure.

Results:

For diagnostic coronary angiograms the median KAP per procedure in the period using conventional magnification was 2124.5 µGy.m2 compared to 1401 µGy.m2 when image matrix magnification was used, a 34% reduction (p < 0.0001). For interventional coronary procedures, the median KAP per procedure in the period using conventional magnification was 3791 µGy.m2 compared to 2568.5 µGy.m2 when image matrix magnification was used, a 32% reduction (p < 0.0001).

Conclusion:

Avoiding using conventional magnification in the cardiac catheter laboratory and using a large screen to magnify images was associated with a statistically significant greater than 30% reduction in KAP.

Advances in knowledge:

This paper is the proof in clinical practice of a theoretical conclusion that radiation dose (KAP) is reduced by use of Image matrix magnification using a large viewing screen without the need to use X-ray tube magnification without significant loss of image resolution in interventional cardiology. The same approach will be useful in interventional radiology.

Introduction

Exposure to radiation during procedures has been shown to increase the risk of cancers, including brain and neck tumours,1 skin tumours,2 and non-cancerous complications such as lens opacities.3–5 Much of the attention to radiation exposure is rightly focused on patient exposure. It is increasingly apparent that high patient exposure also results in high exposure to operators a staff working in the patient’s vicinity during procedures.6

In the cardiac catheter laboratory, the ability to do complex procedures, such as complete total occlusions, often requires longer fluoroscopy times, more acquisition runs and magnification of the image. Therefore, protocols that reduce radiation to patients and operators and catheter laboratory staff become increasing important.7–9 Recent guidelines state what measures can be taken to reduced radiation exposure10–12 and included reducing radiation exposure time, optimising the distance of the operator from the radiation source, reducing frame rate,13 and attention to radiation shielding and several studies have examined how various changes in imaging technique14,15 and the use of specific proprietary software packages available on some fluoroscopy units can reduce radiation exposure.16–20

A large increase in X-ray dose during fluoroscopy and cine capture is caused by conventional magnification, due to its automatic brightness control increasing the exposure values as the field of view decreases to compensate for the corresponding reduction in the brightness gain, often increasing the exposure values and dose by a factor of four per field of view factor of two (i.e. from 25 to 12 cm, dose rate increases from 0.3 mGy/s to 1.23 mGy/s).21 The dose increase is due to an automated system inside the X-ray unit (the Automatic Brightness/Automatic Dose Rate Control System), which increases the dose in image intensifiers in proportion to the area imaged.22 As a result of magnification, the system increases the exposure in order to maintain image quality.23 Fluoroscopy equipment with a flat panel detector magnifies the image by exposing a smaller area of the detector and increases the size of the resultant image on the display screen digitally. In theory, this should not result in any dose increase to the patient. However, as this process reduces the number of X-rays coming from the tube, its effect will reduce the X-ray beam intensity, requiring more exposure to maintain the same level of image quality and reduce noise on the resultant image.24 As a result, the increase in dose for systems with flat panel detectors is less significant than for an image intensifier and the factors resulting in an increase dose are therefore more complex.25,26

Modern catheter laboratory fluoroscopy equipment now often comprises a large in-laboratory imaging screen and associated software which enables the non-magnified image to be “stretched”, displaying the image of a greater area of the screen (image matrix magnification), thus enlarging the in-laboratory image for the operator to visualise without conventional detector-based magnification.

Our Siemens cardiac X-ray equipment uses “zoom” settings to achieve magnification. Siemens describes their zoom factors across a range of detector sizes as: Zoom 0 with a dose factor of 83% and Zoom 1 with a dose factor of 110%.27 The use of these zoom protocols results in a dose increase.

In preliminary experiments using phantoms we found an overall increase of 20.4% in KAP over a seven sequence series of angulations which simulated a coronary angiographic examination when a Zoom 1 protocol was used with our equipment compared to Zoom 0.28 One method of enlarging the image is to obtain a non-magnified image using the zoom 0 protocol and digitally magnify the image (image matrix magnification) on the in-laboratory monitor. Our preliminary study also investigated whether avoiding the use of zoom protocols and using image matrix magnification would affect the resolution of the image produced. We found no difference in the observed image quality which had a resolution of 2.5 line pairs mm−1 with either method, however there was a slight reduction in the resolution of images stored and then retrieved from our Picture Archiving system of 1.6 line pairs mm −1 from 1.8 line pairs mm−1 when zoom magnification was not used.28

Based our preliminary study’s findings, in August 2017 the default means of image magnification in our centre was changed from conventional magnification to an image matrix magnification method using a large viewing screen.

This study is a retrospective analysis of our centre’s radiation exposure and catheter laboratory patient databases to determine whether the theoretical reduction in radiation exposure by adopting the new protocol occurred in clinical practice.

Methods and materials

The study was carried out at The North Wales Cardiac Centre, which has two cardiac catheterisation laboratories. In 2016, one laboratory had a Siemens Artis Zee cardiac configured fluoroscopy unit (Lab 2) in which interventional procedures were preferentially done, and the other laboratory (Lab 1) had older equipment, which had higher radiation exposure per case, in which the majority of diagnostic coronary were done. In the first half of 2017, the older laboratory (Lab 1) was refurbished with identically configured Siemens Artis Zee fluoroscopy unit to Lab 2. The Siemens Artis Zee fluoroscopy unit has a water-cooled silicon detector with a pixel pitch of 184 micrometres, a bit depth of 14 bit which uses conventional magnification factors of 25, 20, 16, and 10 cm, and was installed with a 60-inch operator display. Siemens uses zoom dose factors to describe the resultant dose for each magnification method. It is standardised across their range of detector sizes, and the factors for the equipment used for this research were as follows:

  1. The measured KAP per procedure

  2. The KAP per procedure adjusted for kilogram patient weight

  3. The KAP adjusted for body mass index (BMI).

  4. The number of acquisition runs per procedure

  5. Fluoroscopy time per procedure (this excludes the time of the acquisition runs)

Zoom 0–25 cm pixels 960 × 960, zoom dose factor 83%.

Zoom 1–20 cm pixels 776 × 776, zoom dose factor 110%.25

The zoom protocols used in the clinical practice were reproduced in our previous phantom study.28

Although higher magnification settings are available in practice our operators only use zoom 0 and zoom 1. Both laboratories have a 60-inch in laboratory operator display, which enable image magnification without the use of an increased zoom dose factor. The resulting image digitally is enlarged on the screen by 33%.

The radiation and patient databases were linked to combine details of radiation exposure with patient and procedural characteristics. To compare the radiation exposure before the adoption of the image matrix magnification, we analysed the procedures carried out in the Siemens Artis Zee Lab 2 for the 11 months from February to December 2016 (805 procedures), when zoom 1 protocols were used and compared with the procedures done both laboratories from September to December 2017 (703 procedures), when all images were obtained with zoom 0 and enlarged with image matrix magnification on the large screen. The same operators were doing procedures over both time periods, six interventional consultants undertaking interventional and diagnostic procedures and six consultants doing diagnostic only procedures. Some procedures were done by trainees who were directly supervised by the consultants.

Procedures were classified into those that had only a diagnostic coronary angiogram and those that had an interventional procedure with a stent implanted. Cases that had an invasive diagnostic procedure, such as intravascular ultrasound, optical coherence tomography or pressure wire evaluation, and those having a pacing procedure were excluded but all others were included.

Radiation exposure was measured by the inbuilt KAP meter in the Siemens fluoroscopy equipment. Results were monitored by the in hospital regional medical physics department. Operators wore TLD monitors that were analysed monthly, however as some operators also worked at other centres the TLD monitored doses were not analysed. Operators and patients did not wear real-time radiation monitors so measured skin doses were not available.

Statistical analysis was carried out with StatsDirect v. 3.2.7.29 Variables were analysed with the Shapiro–Wilk W Test and found to be non-normally distributed, therefore medians are quoted and statistical significance tested by Mann–Whitney U tests.

The following variables were compared for the procedures done before, and then after the change in magnification protocol for angiograms and interventional procedures:

  1. The measured KAP per procedure

  2. The KAP per procedure adjusted for kilogram patient weight

  3. The KAP adjusted for body mass index (BMI).

  4. The number of acquisition runs per procedure

  5. Fluoroscopy time per procedure (this excludes the time of the acquisition runs)

Results

1508 procedures were analysed including 693 diagnostic coronary angiograms and 815 interventional procedures. A complete data set was available for patient KAP, number of acquisition runs, fluoroscopy time, patients’ weight and sex. Data for patient height were incomplete with 130 missing data for diagnostic procedures and 141 interventional procedures, so the data comparing BMI with radiation dose excluded those patients. Despite this exclusion, the BMI figures show similar median results for each of the groups and therefore was compared.

The data for diagnostic coronary procedures are shown in Table 1. In the period using conventional magnification, median KAP was significantly higher at 2124.5 µGy.m2 (interquartile range (IQR) 1376–3272) compared to 1401 µGy.m2 (IQR 924–2152) during the period when image matrix magnification was used which is a 34% reduction in KAP (p < 0.0001; a 95% confidence interval (CI) for difference between medians; 476 to 810). Table 1 also shows the results when the KAP is adjusted for patient weight, BMI and number of acquisition runs.

Table 1.

Diagnostic procedures

Conventional magnification Image matrix magnification p
Number of procedures 258 435
Male % 67.08 68.27 0.75
Median age (years) 67 68 0.72
Median weight (kg) 80.2 83.0 0.11
Median body mass index (kg/m2) 27.96 28.74 0.042
Median number of acquisition runs 10 10 0.14
Median fluoroscopy time (minutes) 4.07 2.63 <0.0001
Median KAP (µGy.m2) 2124.5 1401.0 <0.0001
Median KAP/kg (µGy.m2/kg) 25.62 16.97 <0.0001
Median KAP/BMI 0.881 0.588 <0.0001
Median KAP per kg per acquisition run 2.53 1.27 <0.0001
Open in a new tab

BMI, body mass index; KAP, kerma–area product.

The data for interventional procedures are shown in Table 2. In the period using conventional magnification, median KAP was significantly higher at 3791 µGy.m2 (IQR 2472–5587) compared to 2568.5 µGy.m2 (IQR 1699–4090) during the period when image matrix magnification was used, a 32% reduction in KAP (p < 0.0001; with a 95% CI for difference between medians; 744–1315). Table 2. also shows the results when the KAP is adjusted for patient weight, BMI and number of acquisition runs. These results are shown graphically in Figure 1.

Table 2.

Interventional procedures

Conventional magnification Image matrix magnification p
Number of procedures 547 268
Male % 73.95 74.8 0.80
Median age (years) 65 66 0.573
Median weight (kg) 83 82 0.7937
Median body mass index (kg/m2) 27.757 28.228 0.309
Median number of acquisition runs 28 26 0.0019
Median fluoroscopy time (minutes) 11.62 8.415 <0.0001
Median KAP (µGy.m2) 3791 2568.5 <0.0001
Median KAP/kg (µGy.m2/kg) 46.63 31.245 <0.0001
Median KAP/BMI 1.623 1.070 0.0001
Median KAP per kg per acquisition run 1.64 1.23 <0.0001
Open in a new tab

BMI, body mass index; KAP, kerma–area product.

Figure 1.

Figure 1.

Open in a new tab

Combined illustration showing rationale for using digital image matrix magnification The illustration demonstrates how digital magnification can replace X-ray tube magnification instead of X-ray tube magnification with an average reduction in KAP of 32%. KAP, kerma–area product.

When KAP was adjusted for patient weight (KAP/kg) and BMI (KAP/BMI), there remained a significant difference for both diagnostic and interventional procedures between time when conventional magnification and image matrix magnification protocols were used p < 0.0001 (Figure 2).

Figure 2.

Figure 2.

Open in a new tab

Graphs showing (a) procedural KAP µGy.m2 for diagnostic procedures showing individual patient data, median and interquartile range. (b) Procedural KAP µGy.m2 adjusted for patient weight for diagnostic procedures showing individual patient data, median and interquartile range. (c) Procedural KAP µGy.m2 adjusted for patient body mass index for diagnostic procedures showing individual patient data, median and interquartile range. (d) Procedural KAP µGy.m2 for interventional procedures showing individual patient data, median and interquartile range. (e) Procedural KAP µGy.m2 adjusted for patient weight for interventional procedures showing individual patient data, median and interquartile range. (f) Procedural KAP µGy.m2 adjusted for patient body mass index for interventional procedures showing individual patient data, median and interquartile range. KAP, kerma–area product.

In both the diagnostic and interventional procedures, there was a significant reduction in median fluoroscopy time following during the time when image matrix magnification was used; p < 0.0001. However, the results were not adjusted for fluoroscopy time as the overall contribution to radiation dose is much less for fluoroscopy compared to acquisition runs.

Operators subjectively found no difference in operational image quality between conventional and image matrix magnification, but this was not tested objectively in view of our previously reported results showing no difference in image resolution.28

Discussion

Based on the results of our previous phantom experiment,28 it was decided that from August 2017 the default magnification protocol for all procedures should change to image matrix magnification. This current study was a retrospective audit to see if the introduction of the image matrix magnification protocol instead of the previous conventional magnification was associated with a change in radiation exposure. The operators were not blinded to the type of magnification used and were aware that the reason for introducing the image matrix magnification was to try to reduce radiation exposure. There was no significant difference in the median age, sex category, weight, or BMI between the two time periods for either the diagnostic angiogram group or the interventional group. The results show that following adoption of the protocol there was a significant decrease in the KAP per procedure for both diagnostic and interventional procedures and this difference persists when adjusted for patient weight and BMI.

There was a significant decrease in the median fluoroscopy time during the period of image matrix magnification for both diagnostic procedures and interventional procedures. We were unable to provide a separate breakdown of KAP for fluoroscopy and for cine runs and accept this is a weakness in the study; however, the reduction in fluoroscopy time is compelling.

The magnified images may have allowed operators to make earlier judgements about technique, thus shortening the time needed for fluoroscopy. However, the radiation exposure during fluoroscopy is much less than during acquisition runs and reduction in fluoroscopy time during the period of image matrix magnification would have only a small effect on total radiation exposure compared to the reduction in acquisition runs.

The effect of magnification during fluoroscopy also probably contributed to the statistically significant reduction acquisition runs during the period of image matrix magnification for interventional and diagnostic procedures as acquisition runs are often used to help clarify the situation of equipment or effect of intervention, helping judgement during the procedure. This clarification is less frequently necessary if the fluoroscopy is rendered clearer by using a larger image. The reduction in radiation dose following the introduction of image matrix magnification remained significant when adjusted for the reduction in acquisition time or the change in magnification protocol. The effect of magnification on situational judgement has not been investigated in any depth for interventional cardiology or radiology procedures.To date, the advice in interventional cardiology has been to use low fluoroscopy rates and low magnification to minimise radiation dose especially in long interventional procedures.30 Reliable image magnification using large screens could have a significant impact in these procedures.

Our phantom experiment28 showed that there was no significant reduction in resolution for images and the finding that during the image matrix magnification period, there was no need to acquire more images or do more acquisition runs suggests that operators did not need to increase the number of images obtained to compensate for any perceived decrease in image quality. In our phantom experiment, image collimation was fixed, in clinical practice collimation is adjusted dependent on clinical need, and to reduced radiation dose,31 although the frequency of collimation adjustment during procedures was not recorded, it is likely that avoiding conventional magnification reduces the need for associated collimation change.

For procedures, it is often necessary to archive images for subsequent review. For the image matrix magnification, the archived images are the non-magnified images, whereas for the conventional method it is the magnified images that are archived. The process of archiving usually involves compression of the image to reduce the storage space required and this can reduce the resolution of the image. Our previous paper28 showed that the process of image compression had a greater effect on image quality during subsequent review than the change in magnification protocol.

It has previously been shown in our laboratory that increase in KAP has been shown to be associated with patient BMI, so a method that reduces radiation doses is especially important when treating patients with a high BMI, particularly when steep angulations are used.32,33

To demonstrate a change in skin radiation dose to the patient and operator, it would have been useful to have measured real-time skin dose, but this was not available in our study.

In our study, the operators were not blinded to the method of image magnification and were aware with ongoing education of the various methods that should be used to reduce radiation exposure. This may have impacted on the some of the radiation reduction during the image matrix magnification period. However, apart from a reduced number of acquisition runs, which were corrected for and a reduced fluoroscopy time, all other X-ray settings remained the same apart from the magnification protocol, making more likely that it was a change in protocol that resulted in radiation dose reduction rather than other factors. The overall radiation safety protocols and local radiation safety rules remained unchanged throughout all parts of this study

Our study was unblinded using one make of X-ray equipment. Our results need to be validated by repeating the experiment in other laboratories that currently use conventional magnification and have other makes of X-ray equipment. Studies that are able to monitor skin doses to patients and operators would be more informative of radiation dose received rather than radiation dose delivered as measure in our study. A study where the operators were blinded to magnification protocol used would be ideal but impractical as the magnified image during fluoroscopy would be obvious to the operators. However, as our study showed that in our laboratory, a magnification protocol change produces a statistically and clinically significant reduction of radiation dose, it is not believed to be ethical to return to conventional magnification in our laboratory to test this further.

Conclusion

A preliminary phantom-based study in our laboratory had shown that a change from conventional to an image matrix magnification protocol should reduce radiation exposure. Our study of the radiation exposure during diagnostic and interventional procedures before and following a protocol change from conventional magnification to image matrix magnification protocol was associated with a greater than 30% statically and clinically significant reduction in radiation exposure, similar to that shown in our preliminary experiment. Further prospective study in other laboratories is recommended to confirm our findings and if replicated should lead to a change in magnification protocol in cardiac and interventional radiology laboratories.

Contributor Information

Shailesh Dalvi, Email: drdalvi75@yahoo.com.

Hywel Mortimer Roberts, Email: hywel.mortimer-roberts@wales.nhs.uk.

Christopher Bellamy, Email: c.bellamy@btinternet.com.

Michael Rees, Email: michael.rees@me.com.

REFERENCES

  • 1.Heidbuchel H, Wittkampf FHM, Vano E, Ernst S, Schilling R, Picano E, et al. Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures. Europace 2014; 16: 946–64. doi: 10.1093/europace/eut409 [DOI] [PubMed] [Google Scholar]
  • 2.Roguin A, Goldstein J, Bar O, Goldstein JA. Brain and neck tumors among physicians performing interventional procedures. Am J Cardiol 2013; 111: 1368–72. doi: 10.1016/j.amjcard.2012.12.060 [DOI] [PubMed] [Google Scholar]
  • 3.Eagan JT, Jones CT, Roubin GS. Interventional cardiologists: beware and be aware: an updated report of radiation-induced cutaneous cancers. Catheter Cardiovasc Interv 2018; 91: 475–7. doi: 10.1002/ccd.27258 [DOI] [PubMed] [Google Scholar]
  • 4.Sun Z, AbAziz A, Yusof AKM. Radiation-Induced noncancer risks in interventional cardiology: optimisation of procedures and staff and patient dose reduction. Biomed Res Int 2013; 2013: 1–11. doi: 10.1155/2013/976962 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Elmaraezy A, Ebraheem Morra M, Tarek Mohammed A, Al-Habaa A, Elgebaly A, Abdelmotaleb Ghazy A, et al. Risk of cataract among interventional cardiologists and catheterization lab staff: a systematic review and meta-analysis. Catheter Cardiovasc Interv 2017; 90: 1–9. doi: 10.1002/ccd.27114 [DOI] [PubMed] [Google Scholar]
  • 6.Smilowitz NR, Balter S, Weitz G. Occupational hazards of interventional cardiology Cardiovasc. Revasc Med 2013; 14: 223–8. [DOI] [PubMed] [Google Scholar]
  • 7.Domienik J, Gryglak S, Jurewicz J. Characteristics of interventional cardiologists and their work practices for the study on radiation-induced lens opacities based on the methodology developed by ELDO-preliminary results. J Radiat Res 2016; 57: 431–7. doi: 10.1093/jrr/rrw019 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Madder RD, LaCombe A, VanOosterhout S, Mulder A, Elmore M, Parker JL, et al. Radiation exposure among scrub technologists and nurse circulators during cardiac catheterization: the impact of accessory lead shields. JACC Cardiovasc Interv 2018; 11: 206–12. doi: 10.1016/j.jcin.2017.07.026 [DOI] [PubMed] [Google Scholar]
  • 9.Chida K, Kato M, Saito H, Ishibashi T, Takahashi S, Kohzuki M, et al. Optimizing patient radiation dose in intervention procedures. Acta radiol 2010; 51: 33–9. doi: 10.3109/02841850903229141 [DOI] [PubMed] [Google Scholar]
  • 10.Hirshfeld JW, Ferrari VA, Bengel FM, Bergersen L, Chambers CE, Einstein AJ, et al. 2018 ACC/HRS/NASCI/SCAI/SCCT expert consensus document on optimal use of ionizing radiation in cardiovascular imaging-best practices for safety and effectiveness, part 1: radiation physics and radiation biology: a report of the American College of Cardiology Task Force on expert consensus decision pathways. J Am Coll Cardiol 2018; 71: 2811–28. doi: 10.1016/j.jacc.2018.02.017 [DOI] [PubMed] [Google Scholar]
  • 11.Hirshfeld JW, Ferrari VA, Bengel FM, Bergersen L, Chambers CE, Einstein AJ, et al. 2018 ACC/HRS/NASCI/SCAI/SCCT expert consensus document on optimal use of ionizing radiation in cardiovascular imaging-best practices for safety and effectiveness, part 2: radiological equipment operation, dose-sparing methodologies, patient and medical personnel protection: a report of the American College of Cardiology task force on expert consensus decision pathways. J Am Coll Cardiol 2018; 71: 2829–55. doi: 10.1016/j.jacc.2018.02.018 [DOI] [PubMed] [Google Scholar]
  • 12.Fetterly KA, Lennon RJ, Bell MR, Holmes DR, Rihal CS. Radiation dose reduction in the invasive cardiovascular laboratory: implementing a culture and philosophy of radiation safety. JACC: Cardiovasc Interv 2011; 4: 336–43. [DOI] [PubMed] [Google Scholar]
  • 13.Agarwal S, Parashar A, Ellis SG, Heupler FA, Lau E, Tuzcu EM, et al. Measures to reduce radiation in a modern cardiac catheterization laboratory. Circ Cardiovasc Interv 2014; 7: 447–55. doi: 10.1161/CIRCINTERVENTIONS.114.001499 [DOI] [PubMed] [Google Scholar]
  • 14.Fetterly KA, Bell MR. A practical approach to radiation protection for cardiac catheterization laboratory staff. JACC Cardiovasc Interv 2018; 11: 213–4. doi: 10.1016/j.jcin.2017.08.012 [DOI] [PubMed] [Google Scholar]
  • 15.Hirshfeld JW, Fiorilli PN, Silvestry FE. Important strategies to reduce occupational radiation exposure in the cardiac catheterization laboratory: no lower limit. J Am Coll Cardiol 2018; 71: 1255–8. doi: 10.1016/j.jacc.2018.01.025 [DOI] [PubMed] [Google Scholar]
  • 16.Chon MK, Chun KJ, Lee DS, Lee SY, Hwang J, Lee SH, et al. Radiation reduction during percutaneous coronary intervention: a new protocol with a low frame rate and selective fluoroscopic image storage. Medicine 2017; 96: e7517. doi: 10.1097/MD.0000000000007517 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Gunja A, Pandey Y, Xie H, Wolska BM, Shroff AR, Ardati AK, et al. Image noise reduction technology reduces radiation in a radial-first cardiac catheterization laboratory. Cardiovasc Revasc Med 2017; 18: 197–201. doi: 10.1016/j.carrev.2016.12.017 [DOI] [PubMed] [Google Scholar]
  • 18.Miller DL, Vañó E, Bartal G, Balter S, Dixon R, Padovani R, et al. Occupational radiation protection in interventional radiology: a joint guideline of the cardiovascular and interventional radiology Society of Europe and the Society of interventional radiology. Cardiovasc Intervent Radiol 2010; 33: 230–9. doi: 10.1007/s00270-009-9756-7 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19.Wassef AWA, Hiebert B, Ravandi A, Ducas J, Minhas K, Vo M, et al. Radiation dose reduction in the cardiac catheterization laboratory utilizing a novel protocol. JACC Cardiovasc Interv 2014; 7: 550–7. doi: 10.1016/j.jcin.2013.11.022 [DOI] [PubMed] [Google Scholar]
  • 20.Faroux L, Blanpain T, Nazeyrollas P, Tassan-Mangina S, Herce B, Tourneux C, et al. Minimizing exposure to radiation in invasive cardiology using modern dose-reduction technology: evaluation of the real-life effects. Catheter Cardiovasc Interv 2018; 91: 1194–9. doi: 10.1002/ccd.27245 [DOI] [PubMed] [Google Scholar]
  • 21.International Atomic Energy Agency. Good practices in fluroscopy. 2019. Available from: https://www.iaea.org/resources/rpop/health-professionals/radiology/radiation-protection-in-fluoroscopy/good-practices-in-fluoroscopy.
  • 22.AAPM Task Group 125 .Functionality & operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular & interventional angiography systems report no.: 125. College Park, MD: American Association of Physicists in Medicine, Science Council; 2012. [DOI] [PubMed] [Google Scholar]
  • 23.International Atomic Energy Agency. Radiation protection of medical staff in interventional procedures. 2021. Available from: https://www.iaea.org/resources/rpop/health-professionals/interventional-procedures/radiation-protection-of-medical-staff-in-interventional-fluoroscopy.
  • 24.Fauber TL. 5th ed radiographic imaging & exposure. St. Louis: Elsevier; 2017. [Google Scholar]
  • 25.Nickoloff EL. AAPM/RSNA physics tutorial for residents: physics of flat-panel fluoroscopy systems: survey of modern fluoroscopy imaging: flat-panel detectors versus image intensifiers and more. Radiographics 2011; 31: 591–602. doi: 10.1148/rg.312105185 [DOI] [PubMed] [Google Scholar]
  • 26.Huang SY, Jones K. Image wisely. 2014. Available from: http://www.image wisely.org/imaging-modalities/fluoroscopy/articles/huang-patient-specific factors.pdf.
  • 27.Davies M. Request. information about Siemens installed software/hardware In: Siemens Healthcare Limited (email). 2017;.
  • 28.Mortimer-Roberts H, Rees MR. The difference in dose and image quality between magnification methods used after the introduction of larger 60-inch operator screens. BJR Open 2020; 2: 20190044. doi: 10.1259/bjro.20190044 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29. StatsDirect statistical software [program]:StatsDirect https://statsdirect.com/Specifications.aspx. 2019;.
  • 30.Galassi A, Grantham A, Kandzari D, Lombardi W, Moussa I, Thompson C, et al. Percutaneous treatment of coronary chronic total occlusion Part 2: technical approach. Interv Cardiol 2014; 9: 201–7PMIDPMCID. doi: 10.15420/icr.2014.9.3.201 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.International Atomic Energy Agency. 2019. Available from: https://www.iaea.org/resources/rpop.
  • 32.Shah A, Das P, Subkovas E, Buch AN, Rees M, Bellamy C. Radiation dose during coronary angiogram: relation to body mass index. Heart Lung Circ 2015; 24: 21–5. doi: 10.1016/j.hlc.2014.05.018 [DOI] [PubMed] [Google Scholar]
  • 33.Crowhurst JA, Whitby M, Savage M, Murdoch D, Robinson B, Shaw E, et al. Factors contributing to radiation dose for patients and operators during diagnostic cardiac angiography. J Med Radiat Sci 2019; 66: 20–9. doi: 10.1002/jmrs.315 [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The British Journal of Radiology are provided here courtesy of Oxford University Press

RESOURCES