Correction of saturation banding artifacts in magnetic resonance imaging
Systems and methods for correcting saturation banding artifacts in magnetic resonance imaging in which artifact and reference calibration scans are used to create one dimensional or two dimensional correction profiles, which are subsequently applied to actual diagnostic imaging scans to correct the saturation banding artifacts.
1. A method for correcting saturation banding in magnetic resonance imaging comprising:
acquiring at least one artifact calibration scan, with a timing that corresponds to that of an actual diagnostic imaging scan, the at least one artifact calibration scan comprising voxels in a plurality of rows and columns;
acquiring at least one reference calibration scan, with a timing that corresponds to that of the actual diagnostic imaging scan, the at least one reference calibration scan comprising voxels in a plurality of rows and columns;
summing the voxels in each row of the at least one artifact calibration scan to create an artifact row profile,
summing the voxels in each column of the at least one artifact calibration scan to create an artifact column profile,
summing the voxels in each row of the at least one reference calibration scan to create a reference row profile,
summing the voxels in each column of the at least one reference calibration scan to create a reference column profile,
dividing the reference row profile by the artifact row profile in order to obtain a row signal correction profile, and
dividing the reference column profile by the artifact column profile in order to obtain a column signal correction profile;
applying the row and column signal correction profiles to the actual diagnostic imaging scan.
2. The method of claim 1 , wherein applying the row and column signal correction profiles comprises:
multiplying each of the voxels in each column of the actual diagnostic imaging scan by a corresponding value of the column signal correction profile, to obtain a partially corrected diagnostic image, and
multiplying each of the voxels in each row of the partially corrected diagnostic image by a corresponding value of the row signal correction profile, to obtain a fully corrected diagnostic image.
3. The method of claim 1 , wherein applying the row and column signal correction profiles comprises:
multiplying each of the voxels in each row of the actual diagnostic imaging scan by a corresponding value of the row signal correction profile, to obtain a partially corrected diagnostic image, and
multiplying each of the voxels in each column of the partially corrected diagnostic image by a corresponding value of the column signal correction profile, to obtain a fully corrected diagnostic image.
4. The method of claim 1 , wherein a plurality of artifact calibration scans are acquired and wherein summing the voxels in each row of the at least one artifact calibration scan comprises summing an average of the voxels acquired across the plurality of artifact calibration scans.
5. The method of claim 1 , wherein a plurality of reference calibration scans are acquired and wherein summing the voxels in each row of the at least one reference calibration scan comprises summing an average of the voxels acquired across the plurality of reference calibration scans.
6. The method of claim 1 , further comprising normalizing the at least one artifact calibration scan with a mean intensity of the at least one artifact calibration scan and normalizing the at least one reference calibration scan with a mean intensity of the at least one reference calibration scan.
7. The method of claim 1 , wherein determining signal correction profiles further includes applying a Gaussian fit to the row signal correction profile or the column signal correction profile.
8. A magnetic resonance imaging system (MRI) comprising:
an MRI scanner configured to acquire scans, the scans including:
at least one artifact calibration scan, with a timing that corresponds to that of an actual diagnostic imaging scan,
at least one reference calibration scan, with a timing that corresponds to that of an actual diagnostic imaging scan, the actual diagnostic imaging scan comprising a plurality of rows and columns, and
actual diagnostic imaging scans;
a processor configured to
sum the voxels in each row of the at least one artifact calibration scan to create an artifact row profile,
sum the voxels in each column of the at least one artifact calibration scan to create an artifact column profile,
sum the voxels in each row of the at least one reference calibration scan to create a reference row profile,
sum the voxels in each column of the at least one reference calibration scan to create a reference column profile,
divide the reference row profile by the artifact row profile in order to obtain a row signal correction profile, and
divide the reference column profile by the artifact column profile in order to obtain a column signal correction profile, and
apply the row and column signal correction profiles to the actual diagnostic imaging scan to create a corrected image;
a display configured to display the corrected image.
9. The system of claim 8 , wherein the processor is operable to apply the row and column signal correction profiles by multiplying each of the voxels in each column of the actual diagnostic imaging scan by a corresponding value of the column signal correction profile to obtain a partially corrected diagnostic image, and multiplying each of the voxels in each row of the partially corrected diagnostic image by a corresponding value of the row signal correction profile, to obtain a fully corrected diagnostic image.
10. The system of claim 8 , wherein the processor is operable to apply the row and column signal correction profiles by multiplying each of the voxels in each row of the actual diagnostic imaging scan by a corresponding value of the row signal correction profile to obtain a partially corrected diagnostic image, and multiplying each of the voxels in each column of the partially corrected diagnostic image by a corresponding value of the column signal correction profile, to obtain a fully corrected diagnostic image.
11. The system of claim 8 , wherein the MRI scanner is operable to acquire a plurality of artifact calibration scans and wherein the processor is operable to sum averages of the voxels acquired across the plurality of artifact calibration scans.
12. The system of claim 8 , wherein the MRI scanner is operable to acquire a plurality of reference calibration scans, and wherein the processor is operable to sum averages of the voxels acquired across the plurality of reference calibration scans.
13. The system of claim 8 , wherein the processor is further configured to normalize the at least one artifact calibration scan with a mean intensity of the at least one artifact calibration scan and normalize the at least one reference calibration scan with a mean intensity of the at least one reference calibration scan.
14. The system of claim 8 , wherein the processor is further configured to determine signal correction profiles by applying a Gaussian fit to the row signal correction profile or the column signal correction profile.