Optimizing virtual monoenergetic imaging for dual‑energy CT venography assessment of intracranial venous sinus stents.

PURPOSE: To determine a practical virtual monoenergetic imaging (VMI) energy range that improves in‑stent lumen assessment and reduces metal‑related artifacts on dual‑energy CT venography (DECT‑CTV) after intracranial venous sinus stenting.

METHODS

Retrospective single‑center study including 10 patients (13 stents) who underwent DECT‑CTV after venous sinus stenting for idiopathic intracranial hypertension or pulsatile tinnitus. VMI series were reconstructed from 40 to 140 keV in 10‑keV increments. Two neuroradiologists independently scored in‑stent lumen visibility and beam‑hardening/streak artifacts (5‑point Likert). Quantitative analysis used standardized ROI measurements (3 in‑stent and 2 adjacent out‑of‑stent ROIs per stent per keV) and derived metrics including in‑stent attenuation, background noise, CNR, SNR, and dCT_in-out (in‑stent minus out‑of‑stent attenuation).

RESULTS

Qualitatively, both readers preferred intermediate‑high energies (90-100 keV) for overall interpretability. Quantitatively, in‑stent attenuation decreased from 1180.7 ± 245.5 HU (40 keV) to 112.5 ± 15.7 HU (140 keV). Noise and dCT_in-out decreased with increasing energy, whereas CNR decreased with increasing energy. SNR showed no statistically significant differences across energies.

CONCLUSION

For intracranial venous sinus stents on DECT‑CTV, VMI around 90-100 keV provided the best perceived balance between lumen accessibility and artifact suppression. Findings require validation in larger cohorts with device‑specific subgroup analyses and complementary artifact indices.