The purpose of this single-center, prospective, evaluator-blinded study is to establish and optimize the imaging protocol for ferumoxytol-enhanced magnetic resonance venography (Fe-MRV) in patients with venous system diseases. Current gadolinium-based contrast agents used in MRI have limitations, including short circulation half-lives and potential risks for patients with renal impairment. Ferumoxytol, a superparamagnetic iron oxide nanoparticle, offers a longer imaging window and no renal toxicity, making it a promising alternative for vascular imaging. This study will enroll 50 adult patients with suspected or confirmed venous structural abnormalities or circulation disorders. To determine the minimum effective diagnostic dose, each participant will receive a total dose of 3.0 mg/kg, administered as four equal intravenous aliquots, with MRI performed after each aliquot (cumulative doses: 0.75, 1.50, 2.25, and 3.0 mg/kg). Independent, blinded radiologists will evaluate the image quality at each cumulative dose level to determine the lowest possible dose required to achieve successful clinical diagnosis.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
50
Ferumoxytol is a superparamagnetic iron oxide nanoparticle contrast agent. It is administered intravenously at a total dose of 3.0 mg/kg, divided into four equal consecutive aliquots (0.75 mg/kg each).
The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School
Nanjing, Jiangsu, China
RECRUITINGOverall Diagnostic Success Rate
The overall diagnostic success rate is defined as the proportion of vascular segments with an average image quality score of ≥ 3 (evaluated on a 5-point Likert scale, where 1 = non-diagnostic/unusable and 5 = excellent). A segment is considered successfully diagnosed only if two independent, blinded radiologists reach a consensus that it is "diagnosable".
Time frame: Up to 2 days post-intervention
Signal-to-Noise Ratio (SNR) Assessed by Ferumoxytol-enhanced Magnetic Resonance Venography
Signal intensity measurements will be performed using RadiAnt DICOM Viewer software. For each vascular segment, an elliptical region of interest (ROI) covering approximately two-thirds of the vascular lumen will be employed to minimize the effect of partial volume effects. SNR is calculated as the mean signal intensity of the vessel divided by the standard deviation (SD) of the vessel signal intensity. The vessel SD is used in place of background SD, as SNR calculated using background SD is inconsistent across regions of an accelerated sparse image.
Time frame: Up to 2 days post-intervention
Contrast-to-Noise Ratio (CNR) Assessed by Ferumoxytol-enhanced Magnetic Resonance Venography
Signal intensity measurements will be performed using RadiAnt DICOM Viewer software. For each vascular segment, an elliptical ROI covering approximately two-thirds of the vascular lumen will be employed to minimize partial volume effects. The reference signal and standard deviation (SD) of the adjacent muscle will be measured on the same slice. CNR is calculated as the difference between the mean signal intensity of the vessel and that of the adjacent muscle, divided by the square root of the sum of the squared SDs of the vessel and the adjacent muscle.
Time frame: Up to 2 days post-intervention
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