Method and apparatus for calibrating an imaging system

A method for calibration of an imaging system, the imaging system including a radiation source and a digital detector, said method comprising:

• providing a calibration phantom system including a first phantom element material block having a first surface at a first height, said first phantom element material block at least partially comprising a first material having a first attenuation coefficient, and a second phantom element material block having a second surface at a second height different than said first height, said second phantom element material block at least partially comprising a second material having a second attenuation coefficient different than said first attenuation coefficient, said first phantom element material block and said second phantom element material block co-positioned on a detector;
• imaging the calibration phantom system to obtain phantom images using the digital detector and radiation source;
• processing the phantom images;
• extracting a plurality of calibration values from the processed phantom images;
• and
• using the calibration values to adjust a plurality of pixel intensities in the acquired images.

A method for calibration of an imaging system, the imaging system including a radiation source and a digital detector, said method comprising:

• providing a calibration phantom system including a first phantom element material block having a first surface at a first height, said first phantom element material block at least partially comprising a first material having a first attenuation coefficient, and a second phantom element material block having a second surface at a second height different than said first height, said second phantom element material block at least partially comprising a second material having a second attenuation coefficient different than said first attenuation coefficient, said first phantom element material block and said second phantom element material block co-positioned on a detector;
• imaging the calibration phantom system to obtain phantom images, wherein said imaging comprises positioning the calibration phantom system on the digital detector;
• setting image acquisition parameters for at least one image, and acquiring at least one digital image and at least one film-screen image;
• processing the phantom images, wherein said processing comprises pre-processing at least one phantom image, estimating a scatter kernel of at least one pre-processed image, estimating the primary x-ray events on the detector using the scatter kernel estimates, and estimating a radiation pixel noise using the primary x-ray events;
• and
• extracting a plurality of calibration values from the processed phantom images.

A computer readable medium encoded with a program executable by a computer for calibration of an imaging system, the imaging system including a radiation source and a digital detector, said program configured to instruct the computer to:

• image the calibration phantom system to obtain phantom images, wherein the calibration phantom system includes a first phantom element material block having a first surface at a first height, said first phantom element material block at least partially comprising a first material having a first attenuation coefficient, and a second phantom element material block having a second surface at a second height different than said first height, said second phantom element material block at least partially comprising a second material having a second attenuation coefficient different than said first attenuation coefficient, said first phantom element material block and said second phantom element material block co-positioned on a detector, a first radiation shielding plate positioned on top of said first phantom element material block, said first radiation shield plate having at least one opening extending therethrough;
• and
• a second radiation shielding plate positioned on top of said second phantom element material block, said second radiation shield plate having at least one opening extending therethrough;
• process the phantom images;
• extract a plurality of calibration values from the processed phantom images.

A computer readable medium encoded with a program executable by a computer for calibration of an imaging system, the imaging system including a radiation source and a digital detector, said program configured to instruct the computer to:

• provide a calibration phantom system including a first phantom element material block having a first surface at a first height, said first phantom element material block at least partially comprising a first material having a first attenuation coefficient, and a second phantom element material block having a second surface at a second height different than said first height, said second phantom element material block at least partially comprising a second material having a second attenuation coefficient different than said first attenuation coefficient, said first phantom element material block and said second phantom element material block co-positioned on a detector;
• image the calibration phantom system to obtain phantom images, wherein said imaging comprises positioning the calibration phantom system on the digital detector;
• setting image acquisition parameters for at least one image, and acquiring at least one digital image and at least one film-screen image;
• process the phantom images, wherein said processing comprises pre-processing at least one phantom image, estimating a scatter kernel of at least one pre-processsed image, estimating the primary x-ray events on the detector using the scatter kernel estimates, and estimating a radiation pixel noise using the primary x-ray events;
• and
• extract a plurality of calibration values from processed phantom images.