title: Dual-Source Single-Energy Multidetector CT Used to Obtain Multiple Radiation Exposure Levels within the Same Patient: Phantom Development and Clinical Validation.
abstract: Purpose To develop, in a phantom environment, a method to obtain multidetector computed tomographic (CT) data sets at multiple radiation exposure levels within the same patient and to validate its use for potential dose reduction by using different image reconstruction algorithms for the detection of liver metastases. Materials and Methods The American College of Radiology CT accreditation phantom was scanned by using a dual-source multidetector CT platform. By adjusting the radiation output of each tube, data sets at six radiation exposure levels (100%, 75%, 50%, 37.5%, 25%, and 12.5%) were reconstructed from two consecutive dual-source single-energy (DSSE) acquisitions, as well as a conventional single-source acquisition. A prospective, HIPAA-compliant, institutional review board-approved study was performed by using the same DSSE strategy in 19 patients who underwent multidetector CT of the liver for metastatic colorectal cancer. All images were reconstructed by using conventional weighted filtered back projection (FBP) and sinogram-affirmed iterative reconstruction with strength level of 3 (SAFIRE-3). Objective image quality metrics were compared in the phantom experiment by using multiple linear regression analysis. Generalized linear mixed-effects models were used to analyze image quality metrics and diagnostic performance for lesion detection by readers. Results The phantom experiment showed comparable image quality between DSSE and conventional single-source acquisition. In the patient study, the mean size-specific dose estimates for the six radiation exposure levels were 13.0, 9.8, 5.8, 4.4, 3.2, and 1.4 mGy. For each radiation exposure level, readers' perception of image quality and lesion conspicuity was consistently ranked superior with SAFIRE-3 when compared with FBP (P ≤ .05 for all comparisons). Reduction of up to 62.5% in radiation exposure by using SAFIRE-3 yielded similar reader rankings of image quality and lesion conspicuity when compared with routine-dose FBP. Conclusion A method was developed and validated to synthesize multidetector CT data sets at multiple radiation exposure levels within the same patient. This technique may provide a foundation for future clinical trials aimed at estimating potential radiation dose reduction by using iterative reconstructions.©RSNA, 2016 Online supplemental material is available for this article.
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Davide
authors.initials: D
authors.lastname: Bellini
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Ramirez-Giraldo
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Alex
authors.initials: A
authors.lastname: Bibbey
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Justin
authors.initials: J
authors.lastname: Solomon
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Hurwitz
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Alfredo
authors.initials: A
authors.lastname: Farjat
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Achille
authors.initials: A
authors.lastname: Mileto
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Ehsan
authors.initials: E
authors.lastname: Samei
authors.affiliation: From the Department of Radiology (D.B., A.B., L.M.H., A.M., D.M.), Duke Advanced Imaging Laboratories (J.S., E.S.), and Department of Biostatistics and Bioinformatics (A.F.), Duke University Medical Center, Erwin Rd, Durham, NC, 27710; and Siemens Medical Solutions USA, Malvern, Pa (J.C.R.G.).
authors.forename: Daniele
authors.initials: D
authors.lastname: Marin
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000295:instrumentation* / Q000379:methods; D018802:Patient-Centered Care / Q000379:methods; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis* / Q000517:prevention & control; D011835:Radiation Protection / Q000379:methods; D015900:Radiography, Dual-Energy Scanned Projection / Q000295:instrumentation / Q000379:methods; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity