MRI diffusion weighted imaging with estimated motion probing gradient b-factors based on acquired apparent diffusion coefficients for each pixel

A magnetic resonance diagnostic method comprising:

• configuring a data processing system comprising at least one data processor coupled to memory and input/output ports to
• automatically derive an apparent diffusion coefficient based on pixel values of respectively corresponding a pixel positions included in a region of interest for each of at least two original images obtained by imaging a same imaging region of a same subject using at least two respectively corresponding different b-factors;
• automatically estimate a pixel value that would have been obtained by using a b-factor which is larger than the at least two b-factors, for each pixel position included in the region of interest, based on the apparent diffusion coefficient derived for each pixel position;
• automatically acquire the at least two original images;
• and
• automatically estimate signal-to-noise ratio (SNR) in a first original image acquired using a first b-factor bb, based on a signal value S(b) in the first image and signal value S(a) and noise level in a second original image which is one of the at least two original images, and a diffusion coefficient D set in advance for a predetermined portion of the subject positioned in the imaging region,
• wherein the first original image is acquired using a b-factor same as the first b-factor in a case where the SNR estimated by the second estimation unit is equal to or higher than a predetermined threshold value, and the second original image is acquired using a b-factor different from the first b-factor in a case where the estimated SNR is lower than the threshold value.

A magnetic resonance diagnostic apparatus comprising:

• an imaging unit configured to image at least two original images by imaging a same imaging region of a same subject using each of at least two b-factors which are different from each other;
• an estimation unit configured to estimate a pixel value that would have been obtained by using a b-factor which is larger than the at least two b-factors, for each pixel position included in a region of interest in the original images, based on pixel values in each of the at least two original images at respectively corresponding pixel positions;
• and
• a second estimation unit configured to estimate signal-to-noise ratio (SNR) in a first original image acquired using a first b-factor bb, based on a signal value S(b) in the first image and signal value S(a) and noise level in a second original image which is one of the at least two original images, and a diffusion coefficient D set in advance for a predetermined portion of the subject positioned in the imaging region,
• wherein the imaging unit is configured to acquire the first original image using a b-factor same as the first b-factor in a case where the SNR estimated by the second estimation unit is equal to or higher than a predetermined threshold value, and to acquire the second original image using a b-factor different from the first b-factor in a case where the SNR estimated by the second estimation unit is lower than the threshold value.