4D DSA for Dynamic Visualization of Cerebral Vasculature: A Single-Center Experience in 26 Cases

Abstract

Background and purpose: 4D DSA allows acquisition of time-resolved 3D reconstructions of cerebral vessels by using C-arm conebeam CT systems. The aim of our study was to evaluate this new method by qualitative and quantitative means.

Materials and methods: 2D and 4D DSA datasets were acquired in patients presenting with AVMs, dural arteriovenous fistulas, and cerebral aneurysms. 4D DSA was compared with 2D DSA in a consensus reading of qualitative and quantitative parameters of AVMs (eg, location, feeder, associated aneurysms, nidus size, drainage, Martin-Spetzler Score), dural arteriovenous fistulas (eg, fistulous point, main feeder, diameter of the main feeder, drainage), and cerebral aneurysms (location, neck configuration, aneurysmal size). Identifiability of perforators and diameters of the injection vessel (ICA, vertebral artery) were analyzed in 2D and 4D DSA. Correlation coefficients and a paired t test were calculated for quantitative parameters. The effective patient dose of the 4D DSA protocol was evaluated with an anthropomorphic phantom.

Results: In 26 patients, datasets were acquired successfully (AVM = 10, cerebral aneurysm = 10, dural arteriovenous fistula = 6). Qualitative and quantitative evaluations of 4D DSA in AVMs (nidus size: r = 0.99, P = .001), dural arteriovenous fistulas (diameter of the main feeder: r = 0.954, P = .03), and cerebral aneurysms (aneurysmal size: r = 1, P = .001) revealed nearly complete accordance with 2D DSA. Perforators were comparably visualized with 4D DSA. Measurement of the diameter of the injection vessel in 4D DSA was equivalent to that in 2D DSA (P = .039). The effective patient dose of 4D DSA was 1.2 mSv.

Conclusions: 4D DSA is feasible for imaging of AVMs, dural arteriovenous fistulas, and cerebral aneurysms. 4D DSA offers reliable visualization of the cerebral vasculature and may improve the understanding and treatment of AVMs and dural arteriovenous fistulas. The number of 2D DSA acquisitions required for an examination may be reduced through 4D DSA.

Fig 1.

Images show measurements in 2D (A and C) and 4D DSA (B and D) of the vessel diameters of the ICA and VA in lateral projections of the anterior left-sided circulation and the posterior circulation, respectively. Comparable vessel diameters can be evaluated for the ICA (2D DSA = 0.72 cm, 4D DSA = 0.74 cm) and the VA (2D DSA = 0.34 cm, 4D DSA = 0.36 cm).

Fig 2.

Illustrative case 1. MR imaging reveals an incidental AVM of the right occipital lobe in a 47-year-old man with persistent headache. This case demonstrates the potential of 4D DSA (G–L, lower row) to illustrate sequential filling of cerebral vessels concordant with 2D DSA (A–F, upper row). Early 4D volumes show both feeders originating from the posterior parietal artery and the initial enhancement of the nidus. Later volumes of 4D DSA display the compact nidus. Flow-associated/intranidal aneurysms and a direct AVF can be excluded. Late volumes illustrate exclusive venous outflow via superficial veins and the superior sagittal sinus (Martin-Spetzler Score 2). The upper timeline shows the real-time of the filling phases; the lower timeline shows the temporal differences between each image.

Fig 3.

Illustrative case 2. This 39-year-old male patient has left-sided pulsatile tinnitus. Comparable with 2D DSA (A–E, upper row), 4D DSA (F–J) illustrates the early enhancement of a fistulous network on the left-sided skull base originating from the distal ICA. Later volumes show the early filling of the straight sinus via the ectatic basal vein. The upper timeline shows, in real-time, the filling phases; the lower timeline shows the temporal differences between each image.

Fig 4.

Illustrative case 3. This 73-year-old male patient has visual loss on the left side due to a giant sacciform aneurysm of the left carotid-T. Comparable with 2D DSA (A–D, upper row), 4D DSA (E–H, lower row) shows successive intra-aneurysmal filling with contrast medium. The best time for evaluation of the aneurysmal neck was a late arterial volume that shows a fully enhanced aneurysm. Later volumes offer only residual contrast of the aneurysmal sac due to the washout of contrast agent. The upper timeline shows, in real-time, the filling phases; the lower timeline shows the temporal differences between each image.

Fig 5.

This 52-year-old female patient has an AVM in the left hemisphere with feeders from the MCA territory and superficial drainage. The magnified 2D DSA image (A) and the MIP and volume rendered images of 4D DSA (B and C) of the left-sided anterior circulation demonstrate comparable visualization of lenticulostriate arteries in 2D and 4D DSA (red arrows), respectively. Especially, MIP images (B) are a helpful tool for identification of perforators.

Fig 6.

This 59-year-old male patient has pulsatile tinnitus caused by a dAVF (Cognard I) with feeders originating from the posterior meningeal artery and antegrade drainage via the transverse sigmoid sinus. The magnified 2D DSA image (A) and the MIP and volume rendered images of 4D DSA (B and C) of the basilar tip demonstrate comparable visualization of thalamoperforating arteries in both modalities (red arrows).