Related Experiment Videos
Contrast-enhanced 3D-TOF MRA of peripheral vessels: intravascular versus extracellular MR contrast media
M R Engelbrecht1, M Saeed, M F Wendland
1Department of Radiology, University of California San Francisco, 94143-0628, USA.
Abstract:
MR contrast media have been used to improve MR angiography (MRA). Their effect has been particularly beneficial for extracranial MRA. This study evaluated the efficacy of a new formulation of ultrasmall superparamagnetic iron oxide particles (USPIO) on three-dimensional (3D) time of flight (TOF) MRA in the pelvis and lower limb circulation. Each of six dogs received 3 mg/kg of USPIO and .2 mmol/kg of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) bis-methylamide (BMA) by intravenous infusion on separate examinations. Precontrast and postcontrast 3D-TOF MRA images of the lower extremities were acquired over the course of 45 minutes postinjection. Signal intensity (SI) was measured on axial views along the external iliac, femoral, and popliteal arteries. USPIO provided clear demarcation of the major primary, secondary, and tertiary vessels and the improved contrast-to-noise ratio (CNR) was maintained for 45 minutes. Gd-DTPA-BMA provided less signal enhancement than USPIO. The increase in CNR with this agent had significantly declined by 15 minutes after injection. The major vessels could no longer be visualized at 30 and 45 minutes after injection of Gd-DTPA-BMA This study demonstrates the efficacy of USPIO as a contrast medium for 3D-TOF MRA. It was concluded that USPIO provided effective and persistent enhancement of the peripheral vessels.
Insights
Ultrasmall superparamagnetic iron oxide particles (USPIO) effectively enhance magnetic resonance angiography (MRA) of lower limb circulation. USPIO demonstrated superior and sustained vessel enhancement compared to gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) bis-methylamide (BMA).
Area of Science:
- Radiology
- Medical Imaging
- Biomedical Engineering
Background:
- Magnetic Resonance Angiography (MRA) utilizes contrast media to improve visualization of blood vessels.
- Extracranial MRA has particularly benefited from contrast enhancement.
- Evaluating novel contrast agents is crucial for advancing MRA techniques.
Purpose of the Study:
- To assess the efficacy of a new ultrasmall superparamagnetic iron oxide particles (USPIO) formulation for 3D Time-of-Flight (TOF) MRA.
- To compare the performance of USPIO with gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) bis-methylamide (BMA) in pelvic and lower limb MRA.
- To evaluate the duration of contrast enhancement provided by USPIO.
Main Methods:
- Six dogs underwent intravenous infusion of USPIO (3 mg/kg) and Gd-DTPA-BMA (.2 mmol/kg) in separate examinations.
- Three-dimensional (3D) Time-of-Flight (TOF) MRA images of the lower extremities were acquired over 45 minutes post-injection.
- Signal intensity (SI) and contrast-to-noise ratio (CNR) were measured in major arteries (external iliac, femoral, popliteal).
Main Results:
- USPIO provided clear demarcation of vessels and sustained contrast-to-noise ratio (CNR) for 45 minutes.
- Gd-DTPA-BMA showed less signal enhancement and a significant decline in CNR by 15 minutes.
- Major vessels were not visualized with Gd-DTPA-BMA at 30 and 45 minutes post-injection.
Conclusions:
- USPIO is an effective contrast medium for 3D-TOF MRA.
- USPIO offers superior and persistent enhancement of peripheral vessels compared to Gd-DTPA-BMA.
- USPIO holds promise for improving MRA of the pelvis and lower limb circulation.