(Click on the image above to see a full version)

When I was called to see the patient, it sounded just like another trauma admission. The patient in her forties fell at home. CT head, obtained in the Emergency Room, showed right sided subdural hematoma and intracerebral hemorrhage. The patient was somewhat confused yet readily arousable and conversant.

She was taken to the ICU and the neurosurgeon was consulted. Further questioning of the patient and her family, however, raised some red flags. Apparently, she had been complaining of a severe headache for a couple of weeks prior to the admission. This raises the concern for a previous sentinel bleed from a cerebral aneurysm causing a headache.

Most ruptured aneurysmal bleeds cause subarachnoid or intracerebral hemorrhage. Subdural hematoma from a ruptured aneurism is rare (3 to 5%). The question is what was the primary – did the patient fall and had a bleed or the bleed caused her to fall?

MRA (MR angiography) was performed and showed what looks like a right sided AVM (arterio-venous malformation). See black arrow on the upper image above. These are not uncommon and sometimes they bleed. Yet, the neurosurgeon wasn’t convinced that we weren’t dealing with a cerebral aneurysm. MRA is a good study to image larger aneurysms, yet its sensitivity declines when the aneurysm is less than 3-5mm. The clot adjacent to the aneurysm might obscure the image as well.

Cerebral four-vessel angiogram is considered a gold standard for the diagnosis of cerebral aneurysms and AVMs. The procedure is riskier and more involved than CT or MR angiography. In current practice, it has been, for the most part, replaced by CTA and MRA – those test are “good enough” to image most aneurysms and AVMs.

In this case there was no choice but to proceed with a cerebral angiogram. Cerebral angiogram showed a small aneurysm arising from the supraclinoid right internal carotid artery (ICA). See bottom image with a white arrow pointing to the aneurism. The patient was transferred to a facility with a neuro-interventional radiologist available. She underwent a successful coiling of the aneurysm.

Less invasive and, thus, less risky tests have substituted the original or “gold standard” test for the diagnosis of various conditions. We order CT angiography of the chest instead of pulmonary angiogram to diagnose pulmonary embolism. Doppler ultrasound is used instead of venography to diagnose deep vein thrombosis. Soon, we probably will be doing virtual colonoscopy and virtual coronary angiography as well. There is nothing wrong with this trend since the patient’s safety is the primary concern. Sometimes though, anything less than a gold standard is simply not good enough.