Transient enhancement of chronic subdural hematomas: a clinical report of a mimic of acute intracranial hemorrhage.

Background: The incidence of chronic subdural hematomas (cSDHs) is rising, leading to an increased reliance on imaging for diagnosis and management. CT imaging is commonly used in the evaluation of these patients, but transient enhancement of chronic subdural collections can mimic acute-on-chronic subdural hematomas, potentially leading to misdiagnosis.

Objective: To describe cases of transient enhancement of cSDHs after contrast administration.

Methods: A case series of three patients with pre-existing cSDHs was analyzed. One patient underwent middle meningeal artery embolization (MME), and two patients received contrast-enhanced CT (CECT) for other indications. Changes in subdural collection attenuation were assessed on serial imaging.

Results: These three patients with cSDH demonstrated transient enhancement of their subdural collections, which could be mistaken for acute or acute-on-chronic hemorrhage. Recognition of this pattern is critical to avoid misinterpretation, unnecessary radiation exposure, excessive healthcare utilization, and potentially invasive procedures.

Conclusion: Awareness of transient enhancement in chronic subdural collections on CECT is essential for accurate diagnosis. Differentiating this benign imaging artifact from true hemorrhage can prevent unnecessary interventions and optimize patient care.