Diagnostic Performance of a Novel Ferumoxytol-Enhanced Magnetic Resonance Angiography/ Venography on Panvascular Disease

The goal of this observational study is to test the diagnostic performance of ferumoxytol-enhanced magnetic resonance angiography/ venography（FE-MRA/MRV） on panvascular disease. The main questions it aims to answer are:

1. How about the imaging quality of FE-MRA/MRV for panvascular disease?
2. What is the diagnostic performance of FE-MRA/MRV for panvascular disease?

Participants will be divided into two groups based on their symptoms, body signs or laboratory examinations. Participants who suspected with multisite atherosclerotic diseases like coronary artery disease accompany with renal artery stenosis or peripheral arterial disease will be recruited in multisite artery disease (MAD) group. While participants who suspected with venous thromboembolism (VTE) like pulmonary embolism or deep vein thrombosis will be recruited in VTE group. Participants in MAD group will take both FE-MRA and percutaneous selective angiography measurements of coronary, renal, or lower extremity artery, while participant in VTE group need to do pulmonary artery FE-MRA and computed tomography pulmonary angiography (CTPA), lower extremity vein FE-MRV and ultrasonography.

Panvascular disease refers to multi-site vascular disease, presenting as multi-site atherosclerotic disease and venous thromboembolism. There is no gold standard test for panvascular disease up to now. Clinical tests of the suspected population are often carried out by parts and times, and there is no one-stop, panoramic examination on panvascular disease.

Ferumoxytol is a novel and safe MRI contrast agent with an intravascular half-life of approximately 15 hours, enabling simultaneous scanning of multiple sites. At this background, our study intends to investigate the diagnostic efficacy of FE-MRA/MRV in panvascular diseases.

In this study, we plan to enroll 200 patients with suspected panvascular disease. Patients with suspected coronary artery disease, renal artery stenosis, or lower extremity arterial disease will be included in the MAD group, and patients with suspected pulmonary artery embolism and lower extremity venous embolism will be included in the VTE group.

In the MAD group, patients will take both FE-MRA and percutaneous selective angiography of coronary, renal, or lower extremity artery. We will record the FE-MRA image quality score, signal to noise ratio(SNR), compare signal-to-noise ratio（CNR）, whether the coronary, renal, and lower extremity arteries have stenosis greater than 50%, and whether the below-knee arteries are occluded. In the VTE group, patients need to do pulmonary artery FE-MRA and computed tomography pulmonary angiography (CTPA), lower extremity vein FE-MRV and ultrasonography. We will record the image quality scores of FE-MRA of the pulmonary arteries, the FE-MRV the lower extremities, SNR, CNR, the presence of pulmonary embolism or deep vein thrombosis.

The sensitivity, specificity, positive predictive value, and negative predictive value of FE-MRA for the diagnosis of arteries stenosis \>50% will be evaluated by using percutaneous selective angiography as the gold standard and generating subject operating characteristic (ROC) curves. And the sensitivity, specificity, positive predictive value, and negative predictive value of FE-MRA/MRV for the diagnosis of thrombosis in the pulmonary artery or lower extremities will be evaluated by generating ROC curves by using CTPA and venous ultrasound as the reference.

Eligibility Criteria:
Inclusion Criteria:

1. Age 18 to 85 years;
2. Those with suspected multi-site atherosclerotic vascular disease (MAD) (fulfilling both a), and at least two of b), c), and d)):

   1. have at least 1 risk factor for atherosclerosis (hypertension, diabetes mellitus, hyperlipidemia, smoking, and obesity);
   2. Those with suspected coronary atherosclerotic cardiovascular disease: angina symptoms, ST-T changes on ECG;
   3. those with suspected atherosclerotic renal artery stenosis: periumbilical vascular murmur, intractable hypertension, renal insufficiency difficult to explain by other causes;
   4. Those with suspected atherosclerotic lower extremity peripheral arterial disease: intermittent claudication, diminished or absent dorsalis pedis arterial pulses.
3. Those with suspected venous thromboembolism (VTE) (fulfill at least one of a) and b)):

   1. Those with suspected DVT: swelling and pain in the lower extremities;
   2. Those with suspected PE: simplified Wells score ≥ 1.
4. Patients sign an informed consent form.

Exclusion Criteria:

1. Those who are allergic to iodine contrast media or have a history of allergy or hypersensitivity to iron or dextrose;
2. Those who are unable to undergo MRI due to psychological (e.g., suffering from claustrophobia syndrome) or physical reasons (e.g., retention of metallic objects in the body);
3. Those with terminal illness (e.g., suffering from malignant tumors) or with a life expectancy of \<1 year;
4. Liver insufficiency (alanine aminotransferase \> 3 times the upper limit of normal value);
5. Renal insufficiency (eGFR \<30mL/min/1.73cm2);
6. Hyperthyroidism;
7. Those with hemodynamic instability;
8. Pregnant and lactating women;
9. Persons with hearing limitations;
10. Persons with cardiac function class III-IV;
11. Persons on other oral or intravenous iron supplements;
12. Patients with ferrous hemosiderin deposition or hemochromatosis;
13. Patients with acute coronary syndromes;
14. Any other person who, in the opinion of the investigator, should not participate in this study.