What is the appropriate imaging study, computed tomography (CT) head with or without contrast (intravenous iodine), for a patient presenting with the worst headache of their life and blurry vision?

From the Guidelines

For a patient presenting with the worst headache of their life and blurry vision, I recommend ordering a CT head without contrast as the initial imaging study. This is the appropriate first-line imaging test to rapidly evaluate for potentially life-threatening conditions such as subarachnoid hemorrhage, intracranial hemorrhage, or significant mass effect. The "worst headache of life" is a concerning symptom that could indicate a subarachnoid hemorrhage from a ruptured aneurysm, which requires immediate detection, as noted in the ACR Appropriateness Criteria for cerebrovascular diseases, including aneurysm, vascular malformation, and subarachnoid hemorrhage 1. Non-contrast CT is highly sensitive for acute blood and can be performed quickly without the delays associated with contrast administration.

Some key points to consider in this scenario include:

• The high sensitivity of non-contrast CT for detecting acute blood, making it an ideal initial imaging choice for suspected subarachnoid hemorrhage or intracranial hemorrhage.
• The importance of rapid imaging to identify potentially life-threatening conditions that require immediate intervention, such as a ruptured aneurysm, as highlighted in the context of cerebrovascular diseases 1.
• The potential for follow-up imaging with CT angiography (with contrast) or lumbar puncture if the initial non-contrast CT is negative but clinical suspicion remains high for conditions like subarachnoid hemorrhage.
• The consideration of MRI with and without contrast as a subsequent study if the initial CT is negative but symptoms persist, given its sensitivity for detecting various intracranial pathologies, although the initial approach should prioritize non-contrast CT for its speed and sensitivity to acute hemorrhage.

Given the clinical presentation of the worst headache of life and blurry vision, the primary concern is to quickly and accurately diagnose or rule out life-threatening conditions such as subarachnoid hemorrhage, which is effectively done with a non-contrast CT head, as supported by the most recent and relevant guidelines 1.

From the Research

Diagnostic Approach for Worst Headache of Life and Blurry Vision

To determine the best course of action for a patient experiencing the worst headache of their life accompanied by blurry vision, it's essential to consider the role of imaging in diagnosis.

• The patient's symptoms could be indicative of a vascular issue, such as subarachnoid hemorrhage (SAH) or other vascular abnormalities 2.
• Noncontrast CT of the head is often the first line of investigation in the emergency room for neurological symptoms, including headaches, due to its ability to quickly identify subtle vascular changes and other abnormalities 3.
• However, the decision to use CT with or without contrast depends on the suspected underlying cause of the symptoms.
• For vascular abnormalities, noncontrast CT can be useful, but dedicated vascular imaging such as CT angiogram, MR angiogram, venogram, or catheter angiogram may be necessary for confirmation and better characterization of the findings 3, 4.
• The presence of intracranial arterial variations or calcifications can also be evaluated using CT angiography or vessel wall imaging, which may provide insights into the patient's condition and guide further management 5, 6.

Considerations for Imaging Protocols

When designing imaging protocols for patients with suspected vascular abnormalities, several factors must be considered:

• The type of pathology suspected, as different conditions may require tailored imaging approaches 4.
• The use of contrast media, including dose, injection rate, and duration, which can affect arterial enhancement in CT angiography 4.
• The potential benefits of iterative CT reconstruction in improving image quality and reducing radiation dose 4.
• The value of MRI, particularly in imaging small arteries and venous studies 4.

Clinical Implications

Understanding the clinical implications of intracranial arterial calcification and other vascular findings is crucial for patient management:

• Intracranial arterial calcification patterns can indicate the presence of atherosclerotic plaques and may correlate with plaque stability 6.
• The association between calcification patterns and plaque characteristics can inform treatment decisions and risk assessment 6.