Image Quality in Thoracic 4D Cone-beam CT: a Sensitivity Analysis of Respiratory Signal, Binning Method, Reconstruction Algorithm, and Projection Angular Spacing

Overview

Journal Med Phys

Specialty Biophysics

Date 2014 Apr 4

PMID 24694143

Citations 11

Authors

Chun-Chien Shieh

John Kipritidis

Ricky T OBrien

Zdenka Kuncic

Paul J Keall

Affiliations

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Abstract

Purpose: Respiratory signal, binning method, and reconstruction algorithm are three major controllable factors affecting image quality in thoracic 4D cone-beam CT (4D-CBCT), which is widely used in image guided radiotherapy (IGRT). Previous studies have investigated each of these factors individually, but no integrated sensitivity analysis has been performed. In addition, projection angular spacing is also a key factor in reconstruction, but how it affects image quality is not obvious. An investigation of the impacts of these four factors on image quality can help determine the most effective strategy in improving 4D-CBCT for IGRT.

Methods: Fourteen 4D-CBCT patient projection datasets with various respiratory motion features were reconstructed with the following controllable factors: (i) respiratory signal (real-time position management, projection image intensity analysis, or fiducial marker tracking), (ii) binning method (phase, displacement, or equal-projection-density displacement binning), and (iii) reconstruction algorithm [Feldkamp-Davis-Kress (FDK), McKinnon-Bates (MKB), or adaptive-steepest-descent projection-onto-convex-sets (ASD-POCS)]. The image quality was quantified using signal-to-noise ratio (SNR), contrast-to-noise ratio, and edge-response width in order to assess noise/streaking and blur. The SNR values were also analyzed with respect to the maximum, mean, and root-mean-squared-error (RMSE) projection angular spacing to investigate how projection angular spacing affects image quality.

Results: The choice of respiratory signals was found to have no significant impact on image quality. Displacement-based binning was found to be less prone to motion artifacts compared to phase binning in more than half of the cases, but was shown to suffer from large interbin image quality variation and large projection angular gaps. Both MKB and ASD-POCS resulted in noticeably improved image quality almost 100% of the time relative to FDK. In addition, SNR values were found to increase with decreasing RMSE values of projection angular gaps with strong correlations (r ≈ -0.7) regardless of the reconstruction algorithm used.

Conclusions: Based on the authors' results, displacement-based binning methods, better reconstruction algorithms, and the acquisition of even projection angular views are the most important factors to consider for improving thoracic 4D-CBCT image quality. In view of the practical issues with displacement-based binning and the fact that projection angular spacing is not currently directly controllable, development of better reconstruction algorithms represents the most effective strategy for improving image quality in thoracic 4D-CBCT for IGRT applications at the current stage.

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References

Kavanagh A, Evans P, Hansen V, Webb S . Obtaining breathing patterns from any sequential thoracic x-ray image set. Phys Med Biol. 2009; 54(16):4879-88. DOI: 10.1088/0031-9155/54/16/003. View

Yan H, Yin F, Zhu G, Ajlouni M, Kim J . The correlation evaluation of a tumor tracking system using multiple external markers. Med Phys. 2006; 33(11):4073-84. DOI: 10.1118/1.2358830. View

Abdelnour A, Nehmeh S, Pan T, Humm J, Vernon P, Schoder H . Phase and amplitude binning for 4D-CT imaging. Phys Med Biol. 2007; 52(12):3515-29. DOI: 10.1088/0031-9155/52/12/012. View

Yorke E, Rosenzweig K, Wagman R, Mageras G . Interfractional anatomic variation in patients treated with respiration-gated radiotherapy. J Appl Clin Med Phys. 2005; 6(2):19-32. PMC: 5723469. DOI: 10.1120/jacmp.v6i2.2048. View

Vergalasova I, Cai J, Yin F . A novel technique for markerless, self-sorted 4D-CBCT: feasibility study. Med Phys. 2012; 39(3):1442-51. PMC: 3298564. DOI: 10.1118/1.3685443. View

Yan H, Wang X, Yin W, Pan T, Ahmad M, Mou X . Extracting respiratory signals from thoracic cone beam CT projections. Phys Med Biol. 2013; 58(5):1447-64. PMC: 6022850. DOI: 10.1088/0031-9155/58/5/1447. View

Mc Kinnon G, Bates R . Towards imaging the beating heart usefully with a conventional CT scanner. IEEE Trans Biomed Eng. 1981; 28(2):123-7. DOI: 10.1109/TBME.1981.324785. View

Leng S, Zambelli J, Tolakanahalli R, Nett B, Munro P, Star-Lack J . Streaking artifacts reduction in four-dimensional cone-beam computed tomography. Med Phys. 2008; 35(10):4649-59. PMC: 2655146. DOI: 10.1118/1.2977736. View

Roman N, Shepherd W, Mukhopadhyay N, Hugo G, Weiss E . Interfractional positional variability of fiducial markers and primary tumors in locally advanced non-small-cell lung cancer during audiovisual biofeedback radiotherapy. Int J Radiat Oncol Biol Phys. 2012; 83(5):1566-72. DOI: 10.1016/j.ijrobp.2011.10.051. View

10.

Seppenwoolde Y, Shirato H, Kitamura K, Shimizu S, Van Herk M, Lebesque J . Precise and real-time measurement of 3D tumor motion in lung due to breathing and heartbeat, measured during radiotherapy. Int J Radiat Oncol Biol Phys. 2002; 53(4):822-34. DOI: 10.1016/s0360-3016(02)02803-1. View

11.

Sidky E, Pan X . Image reconstruction in circular cone-beam computed tomography by constrained, total-variation minimization. Phys Med Biol. 2008; 53(17):4777-807. PMC: 2630711. DOI: 10.1088/0031-9155/53/17/021. View

12.

Li H, Noel C, Garcia-Ramirez J, Low D, Bradley J, Robinson C . Clinical evaluations of an amplitude-based binning algorithm for 4DCT reconstruction in radiation therapy. Med Phys. 2012; 39(2):922-32. DOI: 10.1118/1.3679015. View

13.

Poulsen P, Fledelius W, Keall P, Weiss E, Lu J, Brackbill E . A method for robust segmentation of arbitrarily shaped radiopaque structures in cone-beam CT projections. Med Phys. 2011; 38(4):2151-6. PMC: 3078162. DOI: 10.1118/1.3555295. View

14.

Pollock S, Lee D, Keall P, Kim T . Audiovisual biofeedback improves motion prediction accuracy. Med Phys. 2013; 40(4):041705. PMC: 3612118. DOI: 10.1118/1.4794497. View

15.

Kini V, Vedam S, Keall P, Patil S, Chen C, Mohan R . Patient training in respiratory-gated radiotherapy. Med Dosim. 2003; 28(1):7-11. DOI: 10.1016/S0958-3947(02)00136-X. View

16.

OBrien R, Cooper B, Keall P . Optimizing 4D cone beam computed tomography acquisition by varying the gantry velocity and projection time interval. Phys Med Biol. 2013; 58(6):1705-23. DOI: 10.1088/0031-9155/58/6/1705. View

17.

Fitzpatrick M, Starkschall G, Antolak J, Fu J, Shukla H, Keall P . Displacement-based binning of time-dependent computed tomography image data sets. Med Phys. 2006; 33(1):235-46. DOI: 10.1118/1.2044427. View

18.

Cooper B, OBrien R, Balik S, Hugo G, Keall P . Respiratory triggered 4D cone-beam computed tomography: a novel method to reduce imaging dose. Med Phys. 2013; 40(4):041901. PMC: 3612115. DOI: 10.1118/1.4793724. View

19.

Sonke J, Zijp L, Remeijer P, Van Herk M . Respiratory correlated cone beam CT. Med Phys. 2005; 32(4):1176-86. DOI: 10.1118/1.1869074. View

20.

Berbeco R, Mostafavi H, Sharp G, Jiang S . Towards fluoroscopic respiratory gating for lung tumours without radiopaque markers. Phys Med Biol. 2005; 50(19):4481-90. DOI: 10.1088/0031-9155/50/19/004. View