Aims and objectives
Quantitative measurements of flow by 2D Phase Contrast MRI (2D PC)require validation using phantom experiments.
This is important toobtain reliable quantitative data on the motion of the cerebrospinalfluid and blood using pulse sequences based on 2D PC methods.
Different types of phantoms,
simulating the flow spins available inthe literature [1,2,3,4].
These phantoms have their undoubtedadvantages,
but they also have limitations.
Work on the creation ofrotation disk phantom in MRI was started at the end of the 1980-s [4].
Despite this,
special calibration tests for MR...
Methods and materials
Nonmagnetic phantom rotated by belt transmission was developed (Fig1 a,b).
Some of the components were made by 3D printing,
also we useLEGO component.
Phantom (160 mm diameter) was filled by agarose gelwith GD-DTPA.
The design of the phantom provides two speed ranges: +/- 20 cm/sec and +/- 72 cm/sec (provided the change of pulleys).
Rotating disc phantom schematicdrawing is shown in Fig.1a,
where: 1 – disc filled agarose gel,
whichcan also be a pulley,
2a,
2b - the pulley,
3 - arm,
4a,
4b,
-...
Results
The designed disk phantom was scanned in different modes and orientations of slices.
On Fig.2 a – T1 weighted image (small tube with water) ,
b- T2 weighted image,
c- rotating phantom in transverse section with flow encoded direction anterior-posterior,
d- rotating phantom in sagittal section with flow encoded direction anterior-posterior sagittal,
e - rotating phantom in sagittal section with flow encoded direction head-feet.
Sagittal section of the phantom and the diagram of linear velocities are shown on the Fig.
3.
The signal depends on...
Conclusion
The MRI compatible rotating disc phantom filled agarose gel provides velocities in physiological range was build.
The relative error in measuring the linear velocity was 6.3%.
The relative error in determination the flow was 6.4%.
The phantom can be used for calibration of MRI units and for study of the effects associated with the flow.
The design of the phantom,
as well as the use of available materials and elements of electromechanical part of the phantom can achieve compact size of the device and make...
Personal information
Dr.
Petraikin Alexey Vl.
MD,
PhD
Pirogov Russian NationalResearch Medical University
(Research Institute of cerebrovascular disease and stroke),
Moscow City Clinic 134,
Moscow,
RF.
[email protected]
Dr.
Sergunova Kristina
Research and Practical Center of Medical Radiology (Health Department of Moscow Government)
Srednyaya Kalitnikovskaya str.,
28/1,
Moscow,
RF,
109029
[email protected]
References
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Bloch KM,
Toger J,
Heiberg E,
Stahlberg F: Accuracy of four-dimensional phase-contrast velocity mapping for blood flow visualizations: a phantom study.
Acta Radiol 2013,
54(6):663-671.
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Durand,
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Bittoun: Precision of Magnetic Resonance Velocity and Acceleration Measurements: Theoretical Issues and...