EDITORIAL
Expert Opinion Is there Still a Role for Filtered-back Projection Reconstruction in Cardiothoracic CT? Phillip M. Boiselle, MD, Dianna M. E. Bardo, MD, Geoffrey D. Rubin, MD, and Denis Tack, MD, PhD Filtered back projection (FBP) reconstruction has been a mainstay of CT imaging for decades. With advances in CT technology and faster computer processing speed, iterative reconstruction methods are increasingly recognized as appealing alternatives to FBP. With this in mind, we asked 3 leading experts the following question:
Is there still a role for filtered-back projection reconstruction in cardiothoracic CT? FBP was chosen as the original CT image reconstruction method because efficiency and speed of obviously better iterative reconstruction techniques (IRT) which produces less noisy, superior image quality was limited by computer processing speed. Need for speed remains important but dose reduction, with maintained, excellent image quality now influences every aspect of CT imaging. IRT enables substantially reduced image noise which results in sharper cardiac structure definition and lessens effects of ‘blooming’ artifacts of calcified atherosclerotic plaque and coronary artery stents. Improved image quality makes post-processing times shorter, increases confidence in interpretation, and improves perception of our specialty. Therefore the role for FBP in cardiothoracic CT is limited, and the usefulness of the technique is diminished by our collective demand for the best for our patients.
Dianna M. E. Bardo, MD Lynwood, WA, USA Remember typewriters? They were minimally configurable offering one font. Yet, until laser and inkjet printers became affordable and reliable, folks still hung onto their old Olivetti’s. In fact, a few still find the imperfections of a typewritten letter nostalgic. CT scans should not be reconstructed on the basis of nostalgia. However, until iterative reconstruction becomes sufficiently consistent, configurable, and ubiquitous, cardiothoracic radiologists will continue to rely on FBP for comfortably familiar and quaintly imperfect transverse reconstructions. While in the near term this means exposing patients to more radiation and lesser image quality, capital replacement cycles and continued commitments by CT manufacturers to refine image quality and radiation dose from both application- and patient-specific perspectives should bring about the extinction of FBP.
Geoffrey D. Rubin, MD Durham, NC, USA With a new CT device characterized by high IT power, FBP no longer has its place in cardiothoracic examinations. FBP is not even provided in new devices such as the fourth generation dual source scanners. FBP is, however, still useful and clinically equivalent to iterative reconstruction (IR) if the radiation dose is set sufficiently high–i.e. over one millisievert–and the IT power too low for enabling fast reconstructions. Such equipment configuration is still widely used as being typical of devices installed before 2012. New devices, or upgraded ones with new detectors and high IT power, enable one to routinely scan below 1 mSv. They reconstruct high quality images using IR only. With these scanners, FBP no longer has a role.
Denis Tack, MD, PhD Braine-L’Alleud, BELGIUM
The authors declare no conflicts of interest. Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/RTI.0000000000000163
J Thorac Imaging
Volume 30, Number 4, July 2015
www.thoracicimaging.com |
Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.
219
Expert Opinion Is there Still a Role for Filtered-back Projection Reconstruction in Cardiothoracic CT? Phillip M. Boiselle, MD, Dianna M. E. Bardo, MD, Geoffrey D. Rubin, MD, and Denis Tack, MD, PhD Filtered back projection (FBP) reconstruction has been a mainstay of CT imaging for decades. With advances in CT technology and faster computer processing speed, iterative reconstruction methods are increasingly recognized as appealing alternatives to FBP. With this in mind, we asked 3 leading experts the following question:
Is there still a role for filtered-back projection reconstruction in cardiothoracic CT? FBP was chosen as the original CT image reconstruction method because efficiency and speed of obviously better iterative reconstruction techniques (IRT) which produces less noisy, superior image quality was limited by computer processing speed. Need for speed remains important but dose reduction, with maintained, excellent image quality now influences every aspect of CT imaging. IRT enables substantially reduced image noise which results in sharper cardiac structure definition and lessens effects of ‘blooming’ artifacts of calcified atherosclerotic plaque and coronary artery stents. Improved image quality makes post-processing times shorter, increases confidence in interpretation, and improves perception of our specialty. Therefore the role for FBP in cardiothoracic CT is limited, and the usefulness of the technique is diminished by our collective demand for the best for our patients.
Dianna M. E. Bardo, MD Lynwood, WA, USA Remember typewriters? They were minimally configurable offering one font. Yet, until laser and inkjet printers became affordable and reliable, folks still hung onto their old Olivetti’s. In fact, a few still find the imperfections of a typewritten letter nostalgic. CT scans should not be reconstructed on the basis of nostalgia. However, until iterative reconstruction becomes sufficiently consistent, configurable, and ubiquitous, cardiothoracic radiologists will continue to rely on FBP for comfortably familiar and quaintly imperfect transverse reconstructions. While in the near term this means exposing patients to more radiation and lesser image quality, capital replacement cycles and continued commitments by CT manufacturers to refine image quality and radiation dose from both application- and patient-specific perspectives should bring about the extinction of FBP.
Geoffrey D. Rubin, MD Durham, NC, USA With a new CT device characterized by high IT power, FBP no longer has its place in cardiothoracic examinations. FBP is not even provided in new devices such as the fourth generation dual source scanners. FBP is, however, still useful and clinically equivalent to iterative reconstruction (IR) if the radiation dose is set sufficiently high–i.e. over one millisievert–and the IT power too low for enabling fast reconstructions. Such equipment configuration is still widely used as being typical of devices installed before 2012. New devices, or upgraded ones with new detectors and high IT power, enable one to routinely scan below 1 mSv. They reconstruct high quality images using IR only. With these scanners, FBP no longer has a role.
Denis Tack, MD, PhD Braine-L’Alleud, BELGIUM
The authors declare no conflicts of interest. Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/RTI.0000000000000163
J Thorac Imaging
Volume 30, Number 4, July 2015
www.thoracicimaging.com |
Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.
219
