Scholars@Duke publication: Photon-Counting Detector vs Energy-Integrating Detector CT Myelography for Detecting CSF-Venous Fistulas in Spontaneous Intracranial Hypotension: Substantially Lower Radiation Dose.

Photon-Counting Detector vs Energy-Integrating Detector CT Myelography for Detecting CSF-Venous Fistulas in Spontaneous Intracranial Hypotension: Substantially Lower Radiation Dose.

Journal articles - Journal Article

Christensen, S; Kranz, PG; Malinzak, MD; Madhavan, AA; Abadi, E; Willhite, J; Gray, L; Zhu, D; Amrhein, TJ

Published in: AJNR Am J Neuroradiol

September 10, 2026

BACKGROUND AND PURPOSE: Photon-counting detector CT (PCD-CT) offers improved spatial resolution compared with conventional energy-integrating detector CT (EID-CT), but session-level dose comparisons in multiacquisition CT myelography (CTM) are limited. We compared radiation dose between PCD-CTM and EID-CTM for detecting CSF-venous fistulas (CVFs) in patients with spontaneous intracranial hypotension (SIH). MATERIALS AND METHODS: This retrospective, single-center cohort study included 603 CTM examinations (EID-CTM, n=470; PCD-CTM, n=133) performed for SIH evaluation between 2020 and 2025. The primary end point was session dose-length product (DLP) for the entire CTM examination. Secondary end points included diagnostic-series volume CT dose index (CTDIvol) and DLP in CVF-positive examinations (Duke CSF-Venous Fistula Confidence Score ≥2) and a scan length proxy (diagnostic DLP/CTDIvol). Radiation dose metrics were compared using nonparametric tests and reported as median (interquartile range). RESULTS: Session DLP was significantly lower for PCD-CTM than for EID-CTM: 1760 (1277-2206) vs 5030 (3476-6559) mGy·cm (median reduction, 65.0%; P < .001). In CVF-positive examinations, PCD-CTM demonstrated significantly lower diagnostic-series CTDIvol (median reduction, 79.9%; P < .001) and diagnostic-series DLP (median reduction, 74.1%; P < .001). These reductions persisted despite PCD-CTM covering a significantly longer scan length (P < .001) and acquiring more series per examination (P < .001). CONCLUSIONS: In patients undergoing CT myelography for CVF evaluation, PCD-CTM was associated with an approximately 65% lower session-level radiation dose than EID-CTM, despite covering a longer anatomic range and more acquisitions.