Intra-arterial contrast administration: a confounding appearance on stroke CT imaging

Area of Science:

• Neuroradiology
• Medical Imaging
• Stroke Diagnosis

Background:

• Stroke is a leading cause of disability, necessitating rapid and accurate diagnosis.
• Advanced imaging techniques like CT angiography (CTA) and CT perfusion (CTP) are crucial for stroke assessment.
• Automated image analysis tools are increasingly used but can be susceptible to technical artifacts.

Purpose of the Study:

• To report a case where incorrect contrast injection during CT imaging led to a false diagnosis of large vessel occlusion.
• To emphasize the critical role of human neuroradiology review in interpreting complex imaging studies.
• To illustrate how technical factors can significantly impact the accuracy of automated image analysis in stroke protocols.

Main Methods:

• A stroke protocol CT study was performed, including non-contrast CT, CTA, and CTP.
• Contrast was inadvertently injected into the right brachial artery.
• Neuroradiology review identified the technical artifact and corrected the interpretation.

Main Results:

• Non-contrast CT head was normal.
• CTP suggested a large infarct in the left anterior circulation territory.
• CTA showed no opacification of the left middle cerebral artery, mimicking a large vessel occlusion.
• Corrected interpretation revealed no actual large vessel occlusion due to misplaced contrast.

Conclusions:

• Technical factors, such as incorrect contrast administration, can create significant imaging artifacts.
• Human oversight by neuroradiologists is essential to prevent misdiagnosis, especially when relying on automated analysis.
• This case underscores the potential pitfalls of automated interpretation in neuroradiology and the need for vigilance.