Related Experiment Video
Updated: Aug 14, 2026
08:41
A MRI-Based Toolbox for Neurosurgical Planning in Nonhuman Primates
Published on: July 17, 2020
Incomplete Spoiling Correction for 3D T 1 Mapping
Gabriela Belsley1, Damian J Tyler1, Matthew D Robson1,2
1Oxford Centre for Clinical Magnetic Resonance Research, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
Magnetic Resonance in Medicine
|August 13, 2026
Summary
Accurate T1 mapping requires correcting for incomplete spoiling in spoiled gradient recalled echo sequences. This method significantly reduces T1 errors, ensuring reliable quantitative MRI results.
Area of Science:
- Magnetic Resonance Imaging (MRI)
- Quantitative Imaging
- Biophysical Modeling
Background:
- Quantitative T1 mapping is crucial for various MRI applications.
- Spoiled gradient recalled echo (SPGR) sequences are widely used for T1 mapping.
- Incomplete spoiling and spatial saturation can introduce significant errors in T1 estimates.
Purpose of the Study:
- To assess the impact of incomplete spoiling and spatial saturation on T1 mapping using variable flip angle (VFA) SPGR.
- To develop and validate a correction method for incomplete spoiling to achieve accurate T1 estimation.
Main Methods:
- Extended phase graph (EPG) simulations were used to derive a correction factor for incomplete spoiling.
- An iterative fitting process refined the correction factor based on T1 estimates.
- The correction method was validated using phantom experiments and applied to in vivo data at 3T.
- Spatial saturation effects were also investigated in phantom studies.
Main Results:
- Uncorrected T1 measurements showed a median error of +7.4% in simulations and phantoms.
- The developed correction reduced the median T1 error to -0.3%.
- In vivo, incomplete spoiling led to T1 overestimation (10-50 ms) dependent on B1+ inhomogeneity.
- Spatial saturation introduced an average T1 bias of -10%.
Conclusions:
- A correction for incomplete spoiling is essential for accurate T1 mapping with VFA SPGR.
- This correction addresses systematic T1 overestimation inherent in the technique.
- Spatial saturation is another critical factor that can disrupt steady-state signals and bias T1 measurements.
Related Concept Videos
01:12Adjusting a Traverse
In the site survey of a four-sided traverse, internal angles are essential to ensure geometric accuracy. The survey revealed that the sum of the measured internal angles was 359 degrees and 48 minutes, which is 12 minutes less than the expected 360 degrees. This discrepancy signals an error likely arising from measurement inaccuracies during the fieldwork.To rectify this error, the adjustment process involved distributing the 12-minute shortfall equally across the four internal angles. By...
01:18Mohr's Circle for Plane Strain
Mohr's circle is a crucial graphical method used to analyze plane strain by plotting strain on a set of cartesian coordinates, where the abscissa is normal strain ∈ and the ordinate is shear strain γ. Similarly to Mohr’s circle for plane stress, two points X and Y are plotted. Their coordinates are (∈x, -γXY) and (∈Y, γXY), respectively.
Mohr's circle visually represents the strain states under various conditions, which is essential for understanding material behavior. The center of Mohr's...
Mohr's circle visually represents the strain states under various conditions, which is essential for understanding material behavior. The center of Mohr's...
01:18Singularity Functions for Bending Moment
Singularity functions simplify the representation of bending moments in beams subjected to discontinuous loading, allowing the use of a single mathematical expression. For a supported beam AB, with uniform loading from its midpoint M to the right side end B, the approach involves conceptual 'cuts' at specific points to determine the bending moment in each segment. By cutting the beam at a point between A and M, the bending moment for the segment before reaching midpoint M is represented using a...
01:23Mohr's Circle for Plane Stress
Mohr's circle is a graphical method for identifying the state of stress at a point in a material, making it easier to analyze stress transformations under plane stress conditions. This two-dimensional technique visualizes both normal and shearing stresses on an element.
Consider a set of Cartesian coordinates. The horizontal and vertical axes correspond to normal stress (σ) and shearing stress (τ), respectively. Two points, points A and B, are defined by the normal and shear stresses on the...
Consider a set of Cartesian coordinates. The horizontal and vertical axes correspond to normal stress (σ) and shearing stress (τ), respectively. Two points, points A and B, are defined by the normal and shear stresses on the...
01:20Midpoint Rule
Approximating areas under curved boundaries is a common problem in applied mathematics, particularly when an exact calculation is difficult or impractical. One effective numerical method for this purpose is the Midpoint Rule, which provides an estimate of the area under a curve by using rectangular approximations over a specified interval.Description of the Midpoint RuleThe Midpoint Rule begins by dividing the given interval into a number of equal subintervals. For each subinterval, the...
01:14Castigliano's Theorem: Problem Solving
The deflection of a simply supported beam that carries a central point load can be analyzed using structural mechanics principles, particularly by applying Castigliano's theorem. This theorem relates the displacement at the load application point to the partial derivatives of the strain energy in the structure. The simply supported beam with a point load at its center has symmetric reaction forces at the supports, each bearing half of the load. The bending moment at any point along the beam is...