Introduction: Ruptured arteriovenous malformations (AVMs) are a frequent cause of intracerebral hemorrhage (ICH). In some cases, compression from the associated hematoma in the acute setting can partially or completely occlude an AVM, making it invisible on conventional angiography techniques. We report on the successful use of conebeam computed tomography angiography (CBCT-A) to precisely identify the underlying angioarchitecture of ruptured AVMs invisible on conventional angiography.
Methods: Three patients presented with intracerebral hemorrhage for which they underwent CBCT-A in addition to digital subtraction angiography and other imaging modalities including magnetic resonance angiography (MRA) and computed tomography angiography (CTA). All patients underwent surgical evacuation due to mass effect from the hematoma. Clinical history, radiographic imaging and surgical records were reviewed. Hematoma volumes were calculated.
Results: CBCT-A demonstrated detailed anatomy of an AVM in all three cases, where no lesion or just a suggestion of a draining vein had been seen on other imaging. Magnetic resonance imaging (MRI) demonstrated enhancement in one patient. CTA demonstrated a draining vein in one patient. Two dimensional digital subtraction angiography (2D-DSA) and 3D rotational angiography (3DRA) demonstrated a suggestion of a draining vein in two cases and no finding in the third. In the two patients in whom CBCT-A was performed prior to surgery, the demonstrated AVM was successfully resected without evidence of residual. In the third patient, CBCT-A allowed precise targeting of the AVM nidus using Gamma Knife radiosurgery.
Conclusions: Conebeam computed tomography angiography should be considered in the workup and subsequent treatment of ICH from ruptured AVMs. In cases where the associated hematoma compresses the AVM nidus, it can have higher sensitivity and anatomic accuracy than traditional angiographic modalities including digital subtraction angiography.
Patient Care: It is hoped that the novel use of this increasingly available imaging technique will provide the clinician with improved detection of otherwise angiographically occult vascular malformations, especially in the acute phase of hemorrhage.
Learning Objectives: 1) Understand the relative utility of using cone-beam CT angiography for detection of angiographically occult AVM
2) Be introduced to the novel use of this imaging technolgy to improve detection of acute ruptured AVM that would otherwise not be detected.