Elsevier

Journal of Clinical Neuroscience

Volume 78, August 2020, Pages 406-408
Journal of Clinical Neuroscience

Tool and Techniques
Unusual enhancement patterns from inadvertent arterial contrast injection during CT angiography

https://doi.org/10.1016/j.jocn.2020.04.094Get rights and content

Highlights

  • Arterial contrast injection can lead to non-diagnostic intracranial studies.

  • This leads to further investigation, increasing patient dose and delaying management.

  • We describe two cases of arterial contrast administration.

  • Various enhancement patterns in normal and variant anatomy are also described.

  • We aim to improve recognition of arterial contrast injection in a timely fashion.

Abstract

Investigation of cerebrovascular incidents typically involve non-contrast intracranial computed tomography (CT) and CT angiography (CTA) of the arch of aorta to vertex with or without CT perfusion. Though rare, inadvertent direct arterial contrast injection is a potentially serious complication which can alter contrast distribution and timing resulting in non-diagnostic intracranial studies. If unnoticed, they can be misinterpreted as pathology leading to further unnecessary investigations, increasing patient radiation dose and delaying appropriate management.

To date, there have been two documented case reports describing arterial contrast injection in cerebral CTA or CT perfusion. We describe two further cases of arterial contrast administration. Furthermore, by describing various contrast enhancement patterns in normal and variant anatomy – such as bovine aortic arch, vertebral artery dominance, posterior inferior cerebellar artery (PICA) continuation of vertebral artery and fetal posterior communicating artery (PCOM) – we hope to improve clinician recognition of inadvertent arterial contrast injection in a timely fashion.

Introduction

A comprehensive imaging protocol for cerebrovascular incidents typically includes non-contrast computed tomography (CT), CT angiography (CTA) from aortic arch to vertex with or without CT perfusion. Although uncommon, inadvertent arterial cannulation (typically brachial artery in the antecubital fossa) may occur and contrast thereafter injected at a high flow rate into the arterial circulation. When this occurs the normal forward flow of blood can be overcome and undiluted contrast retrogradely fills the arterial tree and may, eventually, flow antegradely to vessels that supply the brain. This, in turn, results in unexpected contrast distribution, density and timing resulting in non-diagnostic studies [1], [2]. More importantly, if undetected, this may be misinterpreted as pathology leading to further unnecessary investigations [3], [4], [5].

To our knowledge, there have only been two case reports describing arterial cannulation in cerebral CT perfusion or CTA [3], [4]. We describe two further cases involving inadvertent arterial contrast injection.

Section snippets

Case 1

A 93-year-old woman presented with headache, left retro-orbital pain and reduced vision in the left eye. The following day, she became confused and developed left-sided facial droop. She underwent comprehensive stroke imaging (Fig. 1). During the perfusion study with 40 mL Omnipaque 350 iodinated contrast at 8 mL/s followed by a saline flush of similar volume and rate, she reported left antecubital fossa cannula site pain during injection. Assuming contrast extravasation, the cannula was

Discussion

Recognition of the enhancement patterns in normal and variant anatomy following inadvertent arterial injection is crucial as they can mimic pathology and lead to delayed or inappropriate treatment [4], [5].

The pattern of enhancement varies depending on the rate of injection, arterial anatomy, the type and timing of the scan. Anatomical variants such as vertebral artery dominance, PICA continuation of vertebral artery, fetal PCOM and bovine aortic arch may result in variation in enhancement

Conclusion

Being aware of the potential for arterial cannulation with subsequent intraarterial contrast administration in CT perfusion and CTA studies as well as the imaging appearance of such studies can avoid delays in appropriate diagnosis and treatment.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References (5)

There are more references available in the full text version of this article.

Cited by (0)

View full text