CVFs in SIH: EID vs. PCD CTM

CSF-Venous Fistula Detection in Spontaneous Intracranial Hypotension: Comparative Diagnostic Yields of Energy Integrating Detector Versus Photon Counting Detector CT Myelography

The purpose of this research study is to compare two types of Computed Tomography Myelography (CTM) scans, one on the photon counting detector scanner (called PCD-CTM) and the other on the energy integrating detector scanner (called EID-CTM); both of which doctors usually use to diagnose abnormal connections between the cerebrospinal fluid and the venous system, or CSF-venous fistulas. This study will help to see if the newer PCD-CTM scan can find more spinal fluid leaks [CSF-venous fistulas (CVF)] than the scan that is normally used (EID-CTM).

Study Overview

• Status: Not yet recruiting
• Conditions: Spontaneous Intracranial Hypotension
• Intervention / Treatment: Diagnostic test: photon counting detector CT myelography (PCD- CTM); Diagnostic test: energy integrating detector CT myelography (EID-CTM)

Detailed Description

Spontaneous intracranial hypotension (SIH) is a debilitating condition caused by a spinal CSF leak. One subtype of spinal CSF leak, the CSF-venous fistula (CVF), is a pathologic connection between the CSF-containing nerve root sleeve and an adjacent paraspinal vein. Identifying and localizing the CVF that causes SIH is a critical prerequisite to curative treatment. Visualizing CVFs requires high-quality myelography. Despite improvements in myelographic techniques, CVF identification remains challenging because they are diminutive structures and depend on identifying small volumes of contrast in a paraspinal vein, the "hyperdense paraspinal vein sign."

Compared with EID CT myelography (EID-CTM), PCD-CTM enables much higher spatial resolution and a greater contrast-to-noise ratio, carrying with it the promise of improved detection rates for CVF. Previous publications report early encouraging findings on the benefits of PCD-CTM for CVF detection; however, all prior work has been based on retrospective data. Importantly, these retrospective studies have been biased toward reduced PCD-CTM CVF detection, since only the patients with CVFs that are not definitely identified on EID-CTM undergo PCD-CTM (thus, more challenging cases are completed on the PCD CT). No studies have prospectively demonstrated the additional benefit of PCD-CTM over EID-CTM. Furthermore, no studies have prospectively reported the yield of any type of myelography for CVF detection. Based on the study team's knowledge of these imaging modalities and the imaging appearance of CVFs, PCD-CTM may have a benefit in detecting CVFs that can be missed on EID-CTM, which has been suggested in retrospective studies.

This is a prospective randomized clinical trial designed to assess the diagnostic yield of two different CT scanner types for detecting CSF-venous fistulas (CVFs) during CT myelography. The primary study aim is to compare PCD-CTM to traditional EID-CTM, which is currently the most commonly used technique for CVF detection. Patients meeting inclusion/exclusion criteria will be identified at the Duke CSF Leak Clinic. After informed consent, enrolled participants will be randomized (1:1 allocation) to either PCD-CTM or EID-CTM. CTM technique for both arms will be performed in a standardized manner as part of routine standard of care, as previously published. There will be no additional imaging outside of the current standard of care.

The only intervention in this study is randomization into either of the two imaging arms.

CTM images will be reviewed by the radiologist performing the procedure as part of routine standard of care as well as one additional neuroradiologist. The presence or absence of a CVF will be classified according to the Duke CVF Confidence Score (DCCS). Disagreements will be adjudicated by a third neuroradiologist.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Primary Clinical Research Coordinator; Phone Number: 919-684-7810; Email: latonia.strader@duke.edu
• Study Contact Backup: Name: Clinical Research Specialist; Phone Number: 919-684-3296; Email: amy.cuddington@duke.edu

Study Locations

• United States
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Adult patient,
2. Confirmed diagnosis of SIH using International Classification of Headache Disorders criteria (third edition), and
3. Brain MRI demonstrating at least one positive imaging finding for SIH (e.g., dural enhancement, venous sinus distention, brain sagging, pituitary engorgement, spontaneous subdural fluid collections).

Exclusion Criteria:

1. Prior treatment of a CVF,
2. Inability to undergo both exams (EID-CTM and PCD-CTM) if needed for diagnosis,
3. Spine MRI demonstrating extradural CSF (confirming CSF leak type other than CVF), and
4. inability to provide informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Photon counting detector CT myelography (PCD-CTM)	Diagnostic test: photon counting detector CT myelography (PCD- CTM); Randomization (1:1) to either photon counting detector CT myelography (PCD- CTM) or energy integrating detector CT myelography (EID-CTM)
Other: Energy integrating detector CT myelography (EID-CTM)	Diagnostic test: energy integrating detector CT myelography (EID-CTM); Randomization (1:1) to either photon counting detector CT myelography (PCD- CTM) or energy integrating detector CT myelography (EID-CTM)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic Yield of CTM for CVF Detection Using DCCS	Diagnostic yield will be calculated in both arms as the fraction of patients in whom at least one definite CVF (DCCS 3) is identified. CTM images from both arms will be reviewed by the radiologist performing the procedure as part of routine standard of care, as well as one additional neuroradiologist. The presence or absence of a CVF will be classified according to the Duke CVF Confidence Score (DCCS). Disagreements will be adjudicated by a third neuroradiologist.	Initial interpretation by radiologist performing procedure: within 4 weeks of completion of CTM. Secondary interpretation by additional neuroradiologist and adjudication by third (when needed): completion of study (approximately 3 years)

Collaborators and Investigators

• Sponsor: Duke University
• Collaborators: Siemens Healthineers
• Investigators: Principal Investigator: Timothy J Amrhein, MD, Duke University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): June 1, 2028
• Study Completion (Estimated): August 1, 2028

Study Registration Dates

• First Submitted: May 6, 2026
• First Submitted That Met QC Criteria: May 6, 2026
• First Posted (Actual): May 13, 2026

Study Record Updates

• Last Update Posted (Actual): May 13, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: CSF-venous fistula; Photon counting detector CT myelography; Energy integrating detector myelography
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Intracranial Hypotension
• Other Study ID Numbers: Pro00118497

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No