Image processing method to generate a panoramic image
An image processing method to provide a final panoramic image of at least a portion of a head of a patient, wherein a plurality of different provisional panoramic images are calculated from captured frame data sets through the variation of a reconstruction parameter; the provisional panoramic images are scanned for recognizable structures; the imaging quality of the recognizable structures is determined; the variation of the at least one reconstruction parameter for the calculation of different provisional panoramic images of those frame data sets which have recognizable structures with the highest imaging quality is determined; and with reference to the determined variation of the reconstruction parameter of step a final panoramic image is calculated. A computer-readable storage medium comprising instructions which cause a computer to perform the method and an imaging system having such a storage medium are also described.
1 . An image processing method to provide a final panoramic image of at least a portion of a head, wherein the image processing method comprises:
i. providing a single frame data set comprising a plurality of frames captured by a medical or dental imaging system having a radiation source and a radiation detector which move about a patient on a single trajectory while taking the plurality of frames;
ii. simulating different geometric positions of the portion of the head by calculating by a computer from said single frame data set, and before step iv., at least a first and second provisional panoramic image, wherein for the calculation of the first provisional panoramic image a first reconstruction parameter or value of a reconstruction parameter is applied to the frames of the single frame data set, and for the calculation of the second provisional panoramic image a second reconstruction parameter or value of a reconstruction parameter is applied to the frames of the single frame data set, wherein the second reconstruction parameter or value of a reconstruction parameter is different than the first reconstruction parameter or value of a reconstruction parameter, so that the first calculated provisional panoramic image differs from the second calculated provisional panoramic image;
iii. scanning the first and second provisional panoramic images for recognizable structures;
iv. determining imaging quality of the recognizable structures, comparing the imaging quality of identical recognizable structures of the first and second provisional panoramic images and selecting the recognizable structure of identical recognizable structures of the first or second provisional panoramic image having the highest imaging quality;
v. determining variation of the first or second reconstruction parameter or value of the reconstruction parameter used in step (ii) for calculation of the first and second provisional panoramic images of those frames which have the selected recognizable structures with the highest imaging quality;
vi. calculating by the computer with reference to the determined variation of the first or second reconstruction parameter or value of the reconstruction parameter of step (v) a final panoramic image data set representing a final panoramic image;
vii. displaying the final panoramic image represented by the final panoramic image data set with improved representation of the geometry of anatomical structures of the portion of the head, wherein the improved representation of the geometry comprises at least one of: correction of a translation to the left or right relative to the radiation detector; correction of a translation up or down relative to the radiation detector; or a combination thereof.
2 . The method according to claim 1 , wherein the variation of the first or second reconstruction parameter or value of the reconstruction parameter in step (ii) depends on the dimension of the portion of the head to be imaged.
3 . The method according to claim 1 , wherein the variation of the first or second reconstruction parameter or value of the reconstruction parameter in step (ii) is pre-set.
4 . The method according to claim 1 , wherein determining the imaging quality in step (iv) comprises image data processing of the frames comprising recognizable structures.
5 . The method according to claim 4 , wherein image data processing comprises at least one of: frequency analysis; grey value distribution analysis; brightness distribution analysis.
6 . The method according to claim 1 , wherein the first or second reconstruction parameter comprises at least one of: a rate of overlap of the frames; a rate of scaling of the frames; a pixel shift.
7 . The method according to claim 1 , wherein the first and second provisional panoramic images are divided into a plurality of sections or regions of interest, wherein the plurality of sections or regions of interest is identical for the first and second provisional panoramic images.
8 . The method according to claim 7 , wherein step (v) further comprises that the imaging quality of a recognizable structure of identical sections or regions of interest of the first and second provisional panoramic images is determined and the variation of the first or second reconstruction parameter or value of the reconstruction parameter of those frames forming the section or region of interest of said identical sections or regions of interest which has a recognizable structure with the highest imaging quality is determined.
9 . The method according to claim 1 , wherein in step (vi) the final panoramic image data set is calculated based on the plurality of frames captured in step (i) and the determined variation of the first or second reconstruction parameter or value of the reconstruction parameter of those frames of the first or second provisional panoramic image having the selected recognizable structures with the highest imaging quality.
10 . The method according to claim 1 , wherein in step (vi) the final panoramic image data set is calculated by combining those frames of the first and second provisional panoramic images having the selected recognizable structures with the highest imaging quality.
11 . The method according to claim 1 , wherein in step (vi) the final panoramic image data set is calculated based on one of the first or the second provisional panoramic image and the determined variation of the first or the second reconstruction parameter or value of the reconstruction parameter of those frames of the first or the second provisional panoramic image having the selected recognizable structures with the highest imaging quality.
12 . The method according to claim 1 , wherein calculating the final panoramic image data set comprises scaling the final panoramic image data set.
13 . The method according to claim 1 , wherein the recognizable structure in step (iii) comprises at least a portion of an anatomical structure or of an artificial structure.
14 . A non-transitory computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to:
provide a single frame data set comprising a plurality of frames captured by a medical or dental imaging system having a radiation source and a radiation detector which move about a patient on a single trajectory while taking the frame data set;
calculate from said plurality of frames a plurality of provisional panoramic images by applying at least one different reconstruction parameter or at least one different value of a reconstruction parameter to the plurality of frames for every provisional panoramic image to be calculated, so that each calculated provisional panoramic image differs from another calculated provisional panoramic image;
scan the provisional panoramic images of said plurality of provisional panoramic images for recognizable structures;
determine imaging quality of the recognizable structures, compare the imaging quality of identical recognizable structures of different provisional panoramic images and select the recognizable structure of identical recognizable structures of different provisional panoramic images having the highest imaging quality;
determine variation of the at least one reconstruction parameter or value of the reconstruction parameter for calculation of the plurality of provisional panoramic images of those frames which have selected recognizable structures with the highest imaging quality; and
calculate with reference to the determined variation of the at least one reconstruction parameter or value of the reconstruction parameter a final panoramic image data set representing a final panoramic image; and
display the final panoramic image represented by the final panoramic image data set with improved representation of the geometry of anatomical structures of the portion of the head, wherein the improved representation of the geometry comprises at least one of: correction of a translation to the left or right relative to the radiation detector; correction of a translation up or down relative to the radiation detector; or a combination thereof.
15 . A medical or dental imaging system for generating an image of at least a part of the head of a patient, comprising:
a radiation source and a radiation detector which are configured to move about a patient to capture a plurality of frames, and
a computer which is operatively connected to the radiation detector to receive the plurality of frames and which is programmed to:
receive the plurality of frames captured by the radiation source and the radiation detector;
calculate from said plurality of frames a plurality of provisional panoramic images by applying at least one different reconstruction parameter or at least one different value of a reconstruction parameter to the plurality of frames for every provisional panoramic image to be calculated, so that each calculated provisional panoramic image differs from another calculated provisional panoramic image;
scan the provisional panoramic images of said plurality of provisional panoramic images for recognizable structures;
determine imaging quality of the recognizable structures, compare the imaging quality of identical recognizable structures of different provisional panoramic images, and select the recognizable structure of identical recognizable structures of different provisional panoramic images having the highest imaging quality;
determine variation of the at least one reconstruction parameter or value of the reconstruction parameter for calculation of the plurality of provisional panoramic images of those frames which have selected recognizable structures with the highest imaging quality;
calculate with reference to the determined variation of the at least one reconstruction parameter or value of the reconstruction parameter a final panoramic image data set representing a final panoramic image; and
display the final panoramic image represented by the final panoramic image data set with improved representation of the geometry of anatomical structures of the portion of the head, wherein the improved representation of the geometry comprises at least one of: correction of a translation to the left or right relative to the radiation detector; correction of a translation up or down relative to the radiation detector; or a combination thereof.
16 . The medical or dental imaging system according to claim 15 , wherein the radiation source comprises an X-ray radiation source.
17 . The method according to claim 8 , wherein in step (vi) the final panoramic image data set is calculated based on the plurality of frames captured in step (i) and the determined variation of the first or second reconstruction parameter or value of the reconstruction parameter of the frames forming those respective sections or regions of interest of the first or second provisional panoramic image which have the selected recognizable structures with the highest imaging quality.
18 . The method according to claim 8 , wherein in step (vi) the final panoramic image data set is calculated by combining those respective sections or regions of interest of the first or second provisional panoramic image which have the selected recognizable structures with the highest imaging quality.
19 . The method according to claim 8 , wherein in step (vi) the final panoramic image data set is calculated based on the first or second provisional panoramic image and the determined variation of the first or second reconstruction parameter or value of the reconstruction parameter of the frames forming those respective sections or regions of interest of the first or second provisional panoramic image which have the selected recognizable structures with the highest imaging quality.