Digital Subtraction Angiography for CT Angiogram Negative Haemorrhages

Area of Science:

• Neurology
• Radiology
• Vascular Imaging

Background:

• Subarachnoid hemorrhage (SAH) diagnosis often requires identifying the bleeding source.
• CT angiography (CTA) is a common initial imaging modality.
• Digital subtraction angiography (DSA) is frequently used when CTA is negative.

Purpose of the Study:

• To determine if negative CT angiography (CTA) findings can reliably exclude aneurysms in patients with acute subarachnoid hemorrhage (SAH).

Main Methods:

• Retrospective analysis of 857 digital subtraction angiographies (DSAs) performed between August 2010 and July 2014.
• Included patients with confirmed SAH and negative CTA results.
• Imaging reviewed by a fellowship-trained neuroradiologist.

Main Results:

• 5.83% of DSAs (50/857) were performed in 35 patients with CTA-negative SAH.
• Only 8.57% (3/35) of these patients had positive DSA findings.
• One case of posterior inferior cerebellar artery aneurysm was missed on CTA due to incomplete head coverage.

Conclusions:

• Technically adequate CT angiography (CTA) with negative findings is reliable for excluding aneurysms in subarachnoid hemorrhage (SAH) patients.
• Further investigation with digital subtraction angiography (DSA) may not be necessary in CTA-negative SAH cases.
• Larger prospective studies are needed to confirm these findings.