Photon Counting Detector CT Angiography for Localization of the Artery of Adamkiewicz

Photon counting detector CT is a relatively new technology that is becoming increasingly prevalent. In recent years, photon counting CT has been shown to have benefits in numerous neuroradiologic clinical applications, including temporal bone imaging, detection of spinal CSF leaks, and CT angiography of the head, neck, and spine. New uses for photon counting detector CT continue to emerge, capitalizing on the high spatial resolution and other advantages of this technology to improve patient care. One potential application in the spine is the detection and localization of the artery of Adamkiewicz, which provides the dominant supply to the inferior portion of the anterior spinal artery. Localization of this artery is sometimes desired prior to surgeries requiring ligation of the foraminal neurovascular complex. Traditional energy integrating detector CT is useful but imperfect for detection of this relatively small and transiently opacifying vessel. The improved spatial resolution and spectral information obtained with photon counting CT may help improve detection of the artery of Adamkiewicz. In this clinical report, we outline a protocol for imaging the artery of Adamkiewicz with photon counting detector CT and describe a comparative analysis of three different reconstruction techniques in six consecutive patients who underwent this exam. We found that an intermediate sharp vascular kernel (Bv60) reconstructed with a low energy threshold outperformed other conditions, including a sharper kernel and a low keV virtual monoenergetic reconstruction.ABBREVIATIONS: AKA = artery of Adamkiewicz or great radiculomedullary artery; CNR = contrast-to-noise ratio; EID = energy integrating detector; PCD = photon counting detector QIR = quantum iterative reconstruction; T3D = low energy threshold; UHR = ultra-high resolution.