Abstract
This chapter provides an overview of the GE Discovery CT750HD dual energy imaging capability known as gemstone spectral imaging (GSI). The CT750HD is a single X-ray source system that employs fast kVp switching for dual energy acquisitions. This acquisition method enables precise temporal registration of the dual-energy sinograms, projection-based material decomposition, and delivers a full 50 cm material decomposition scan field of view. The subsystem technologies employed to achieve the dual energy acquisitions are detailed in the discussion of system design. Calibration of fast kVp switching data, material decomposition, and visualization of the resulting images are covered in the image reconstruction and post processing sections. The chapter closes with GSI implementation in the context of challenging diagnostic applications.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsNotes
- 1.
Since the kVp rise and fall are incorporated into the view measurements, a fast switching generator is required, and any remaining low level nonidealities are accounted for in the spectral calibration of the data.
- 2.
Afterglow refers to a secondary decay of light emitting from the scintillator for several milliseconds after the X-ray source is turned off. It carries a part of the signal from one view to the next during a scan, thereby smearing the information, and potentially causing unwanted spectral decomposition artifact.
- 3.
Material density images represent of the effective density for the material necessary to create the observed dkVp measurements. In other words, pure water appears as 1,000 mg/mL in a water image, 20 mg/mL of dilute iodine is labeled as such an iodine image, etc.
- 4.
ASIR focuses on the statistical modeling of the noise properties of the system in conjunction with the properties of the scanned object. As a result, it provides significant benefit for those examinations that may experience limitations due to noise in the reconstructed images. In the case of spectral imaging, this is applied to reduce the noise in the material density images to enhance image quality.
References
Alvarez R, Macovski A (1976) Energy-selective reconstructions in X-ray CT. Phys Med Biol 21(5):733–744
Kalender WA, Perman WH, Vetter JR, Klotz E (1986) Evaluation of a prototype dual-energy computed tomographic apparatus. I. Phantom studies. Med Phys 13(3):334–339
Alvarez R, Seppi E (1979) A comparison of noise and dose in conventional and energy selective computed tomography. IEEE Trans Nucl Sci NS–26(2):2853–2856
Li B, Yadava G, Hsieh J (2010) Head and body CTDIw of dual energy x-ray CT with fast-kVp switching. Paper 7622–69, SPIE Medical Imaging, San Diego, Feb 2010
Fan J, Hsieh J, Sainath P, Crandall PS (2010) Evaluation of the adaptive statistical iterative reconstruction technique for cardiac computed tomography imaging. Paper 7622–101, SPIE Medical Imaging, San Diego, Feb 2010
Tkaczyk JE, Langan DA, Wu X, Xu D, Hara A, Pavlicek W, Licato P, Leverentz J (2009) Quantization of liver tissue in fast-switched dual kVp computed tomography using linear discriminant analysis. Paper 7258–15, SPIE Medical Imaging, Feb 2009
Joshi MC, Langan DA, Sahani DV, Ramesh AK, Aluri S, Procknow K, Wu X, Rahul Bhotika R, Okerlund DR (2010) Fast kV switching dual energy CT effective atomic number accuracy for kidney stone characterization. Paper 7622–128, SPIE Medical Imaging, Feb 2010
Pack JD, Langan DA, Wu X, Xu D, Benson TM, Schmitz AM, Tkaczyk JE, Pavlicek W, Boltz TF II, Payden R, Licato P, Leverentz J (2009) Fast kVp switching CT imaging of a dynamic cardiac phantom. Paper 7258–150, SPIE Medical Imaging, Feb 2009
Pavlicek W, Panse P, Amy K, Hara AK, Boltz T, Paden R, Licato P, Chandra N, Okerlund DR, Bhotika R, Langan DA (2010) Initial use of fast switched dual energy CT for coronary artery disease. Paper 7622–66, SPIE Medical Imaging, Feb 2010
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2011 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Chandra, N., Langan, D.A. (2011). Gemstone Detector: Dual Energy Imaging via Fast kVp Switching. In: Johnson, T., Fink, C., Schönberg, S., Reiser, M. (eds) Dual Energy CT in Clinical Practice. Medical Radiology(). Springer, Berlin, Heidelberg. https://doi.org/10.1007/174_2010_35
Download citation
DOI: https://doi.org/10.1007/174_2010_35
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-01739-1
Online ISBN: 978-3-642-01740-7
eBook Packages: MedicineMedicine (R0)