European Radiology

, Volume 29, Issue 2, pp 645–653 | Cite as

Dose reference levels and clinical determinants in stroke neuroradiology interventions

  • Jad FarahEmail author
  • Aymeric Rouchaud
  • Theophraste Henry
  • Catherine Regen
  • Cristian Mihalea
  • Jacques Moret
  • Laurent Spelle



To establish dose reference levels (RLs) for stroke interventions while carefully analysing the impact of clinical and technical parameters on patient exposure.


The study retrospectively analysed data from 377 stroke patients prospectively collected between 15 October 2015 and 30 March 2017 at a single, level-3 stroke centre equipped with Philips Allura Clarity systems. Local dose RLs were first derived as the 75th percentile of the dose area product (DAP), cumulative air kerma (Ka,r), fluoroscopy time (FT) and the number of images (NI). Univariate and multivariate negative binomial regressions were considered for the statistical analysis to investigate the dose variability with clinical and technical parameters such as patient’s age and sex, occlusion removal technique, number of passages, single-plane or biplane equipment, etc.


Local stroke dose RLs were derived in terms of total DAP (162 Gy cm2), Ka,r (854 mGy), FT (42 min) and NI (559). Gender (relative dose multiplier (RDM) 1.31; 95% CI 1.12–1.45), number of passages (RDM 1.22 per passage; 95% CI 1.10–1.22) and procedure success (RDM 0.52, 95% CI 0.55–0.80) proved to be key parameters affecting patient dose. Meanwhile the statistical analysis did not find any difference in relative dose received by patients owing to age, baseline NIHSS score, occlusion removal technique, posterior circulation, support of an anaesthesiologist or use of biplane equipment.


Stroke dose RLs introduced in this work promote the optimisation of patient doses. Male gender, number of passages and success of recanalisation are independent key parameters affecting patient dose.

Key Points

• Stroke dose RLs derived in terms of total DAP (162 Gy cm 2 ), K a,r (854 mGy), FT (42 min) and NI (559) will help optimise the radiation safety of patients treated with mechanical thrombectomy.

• Male gender (relative dose multiplier 1.31; 95% CI 1.12–1.45), number of passages (RDM 1.22 per passage; 95% CI 1.10–1.22) and success of recanalisation TICI score > 2b (RDM 0.52, 95% CI 0.55–0.80) are independent key parameters affecting patient dose.

• Stent retriever or aspiration technique showed no significant difference in terms of the dose delivered to the patient; neither technique should be favoured for dosimetric reasons provided that there is no difference regarding clinical outcomes.


Stroke Thrombectomy Radiation protection Patients Statistics 



As low as reasonably achievable


Confidence interval


Cumulative air kerma at interventional reference point


Dose area product


Diagnostic reference levels


Flat-panel CT


Fluoroscopy time


International Commission on Radiological Protection


Number of images


National Institutes of Health Stroke Scale


Picture Archiving and Communication System


Relative dose multiplier


Reference levels


Stroke Interventional Laboratory Consensus


Thrombolysis in cerebral infarction



The authors state that this work has not received any funding.

Compliance with ethical standards


The scientific guarantor of this publication is Pr Laurent Spelle.

Conflict of interest

The authors of this manuscript declare relationships with the following companies: Philips, Medtronic, Stryker, MicroVention, Balt.

Statistics and biometry

One of the authors has significant statistical expertise.

Informed consent

As a follow-up evaluation on stroke patients, informed consent was not required.

Ethical approval

As a follow-up evaluation, the study did not involve any change in the standard procedure and did not require the identification of individuals.


• retrospective

• observational

• performed at one institution


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Copyright information

© European Society of Radiology 2018

Authors and Affiliations

  1. 1.Hopitaux Universitaires Paris-Sud, Hopital du Kremlin-BicetreLe Kremlin-BicêtreFrance

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