Optimal Visualization and Measurement of the Extracranial Middle Meningeal Artery in CTA.

Background: This study aimed to optimize the visualization and measurement of the extracranial middle meningeal artery (exMMA) using head and neck CT angiography (CTA) to enhance trans-exMMA embolization therapy.

Methods: CTA images from 80 patients (40 males, 40 females; aged 21-80 y) were analyzed. Imaging postprocessing techniques, including plain view, multiplanar reconstruction (MPR), and 3D volume rendering (3DVR), were used to optimize exMMA visualization. The optimal window length (WL) was determined by calculating the average Hounsfield unit (HU) from 160 exMMAs. A 95% CI for window width (WW) was established based on measured HU values.

Results: Within the 95% CI range (38-574 HU) of WW, and using the optimal WL (168 HU), exMMAs were clearly visualized. A quintisected division of the 95% CI of WW was applied, resulting in 5 different WW settings for exMMA diameter measurement: 78, 156, 234, 312, and 390 HU. At the optimized WL/WW setting (168/78), the average diameters of the exMMA were measured as follows: 1.62±0.57 mm in the plain view, 1.56±0.46 mm in the 3DVR view, and 1.51±0.45 mm in the MPR view (P=0.020 compared to the plain view).

Conclusions: ExMMA diameters decreased as WW values increased, while the observation rate of exMMA decreased with higher WW values. Optimized WL/WW settings (168/78) in plain view provided the most accurate exMMA measurements.