Application of 4-Dimensional Digital Subtraction Angiography for Dural Arteriovenous Fistulas

Background Three-dimensional reconstruction of digital subtraction angiography (3D-DSA) is a useful imaging modality for assessing complex cerebrovascular lesions. However, due to the importance of flow over time in certain vascular lesions, 3D-DSA is of less value as it lacks the temporal resolution. Dural arteriovenous fistulas (AVFs) are complex lesions in which an arteriovenous shunt exists between meningeal arteries and a dural venous sinus or cortical vein. Traditional 2D-DSA, especially with superselective injections of feeding arteries, is currently the gold standard for assessment, but overlapping of opacified vessels can complicate interpretation. A novel imaging technique, 4D-DSA, merges 3D reconstructions of multiple temporal series. It offers a unique perspective on complex cerebrovascular lesions and may offer several advantages in the assessment of dural AVF. Methods 4D-DSA images were acquired in 5 patients who presented with dural AVFs. All relevant clinical data, imaging, and procedural/operative reports were reviewed retrospectively. 4D-DSA images were reconstructed on a separate 3D workstation and compared to 2D and 3D-DSA images in an offline fashion. Results In all 5 cases, 4D-DSA proved to be useful in lesion assessment and treatment planning. This included observation (n = 2), microsurgery (n = 1), and endovascular embolization (n = 2). Conclusions In the small series of patients in which it has been evaluated, 4D-DSA offers several advantages in assessing dural AVFs. The ability to see and manipulate feeding arteries in 3D combined with temporal resolution was useful in assessment and treatment planning. Continued experience with this imaging technique will be needed to identify its optimal use.