radiology case presentation david r. beckert, ms-4 11/8/05
TRANSCRIPT
Case Background
• Clinical History: 22 y.o. female presented to Neuro angio for imaging of AVM, which was discovered at OSH, in order to proceed to interventional radiology for gamma knife ablation procedure.
• (Note: Unclear as to her original complaint that lead to the discovery of the AVM at the OSH)
Arteriovenous malformations
• Intracranial AVMs = 0.1% prevalence (aneurysms =1.0%).
• Supratentorial lesions = 90%
• Posterior fossa = 10%
• AVMs account for:– 1 to 2 % of all strokes– 3 % of strokes in young adults– 9 % of subarachnoid hemorrhages
AVM Clinical Summary
• AVMs usually present in the second to the fourth decade of life.
• Presentation: – Intracranial hemorrhage = 41-79 %– Seizures = 11-33 %– Headaches or progressive deficit– Younger patients (<30 yo) most often present
with seizures, while older patients more commonly present with hemorrhage
AVM Imaging
• Angiography is the gold standard for the diagnosis, treatment planning, and follow-up after treatment
• Anatomical and physiological information such as the nidus configuration, its relationship to surrounding vessels, and localization of the draining or efferent portion of the AVM are readily obtained
• Contrast transit times provide additional useful information regarding the flow state of the lesion; this is critical for endovascular treatment planning
• AVMs typically first discovered via MRI/CT• MRI- very sensitive for location purposes and following
pts after treatment
AVM Treatment• Pt. Age is most important factor• Options include surgery, stereotactic radiosurgery, and
endovascular embolization• Stereotactic radiosurgery — Stereotactically focused high energy
beams of photons or protons to a defined volume containing the AVM nidus induces progressive thrombosis.
• Time course usually one to three years, and the time between treatment and obliteration is referred to as the latency period.
• Once the lesion is completely obliterated, the hemorrhage risk from the AVM is very low
• Successful AVM obliteration with radiosurgery depends upon lesion size and dose of radiation (complications also depend on location/size of AVM and volume treated)