PMID- 33988849 OWN - NLM STAT- MEDLINE DCOM- 20210922 LR - 20240403 IS - 2473-4209 (Electronic) IS - 0094-2405 (Print) IS - 0094-2405 (Linking) VI - 48 IP - 9 DP - 2021 Sep TI - Energy-integrating-detector multi-energy CT: Implementation and a phantom study. PG - 4857-4871 LID - 10.1002/mp.14943 [doi] AB - PURPOSE: Multi-energy computed tomography (MECT) has a great potential to enable many novel clinical applications such as simultaneous multi-contrast imaging. The purpose of this study was to implement triple-beam MECT on a traditional energy-integrating-detector (EID) CT platform (EID-MECT). METHODS: This was accomplished by mounting a z-axis split-filter (0.05 mm Au, 0.6 mm Sn) on Tube A of a dual-source EID CT scanner. With the two split x-ray beams from Tube A and the third beam from Tube B, three beams with different x-ray spectra can be simultaneously acquired. With Tube B operated at 70 or 80 kV and Tube A at 120 or 140 kV, four different triple-beam configurations were calibrated for MECT measurements: 70/Au120/Sn120, 80/Au120/Sn120, 70/Au140/Sn140, and 80/Au140/Sn140 kV. Iodine (I), gadolinium (Gd), bismuth (Bi) samples, and their mixtures were prepared for 2 three-material-decomposition tasks and 1 four-material-decomposition task. For each task, samples were placed in a water phantom and scanned using each of the four triple-beam configurations. For comparison, the same phantom was also scanned using three other dual-energy CT (DECT) or MECT technologies: twin-beam DECT (TB-DECT), dual-source DECT (DS-DECT), and photon-counting-detector CT (PCD-CT), all with optimal x-ray spectrum settings and at equal volume CT dose index (CTDIvol). The phantom for four-material decomposition (I/Gd/Bi/Water imaging) was scanned using the PCD-CT only (140 kV with 25, 50, 75, and 90 keV). Image-based material decomposition was performed to acquire material-specific images, on which the mean basis material concentrations and noise levels were measured and compared across all triple-beam configurations in EID-MECT and various DECT/MECT systems. RESULTS: The optimal triple-beam configuration was task-dependent with 70/Au120/Sn120, 70/Au140/Sn140, and 70/Au120/Sn120 kV for I/Gd/Water, I/Bi/Water, and I/Gd/Bi/Water material decomposition tasks, respectively. At equal radiation dose level, EID-MECT provided comparable or better quantification accuracy in material-specific images for all three material decomposition tasks, compared to EID-based DECT and PCD-CT systems. In terms of noise level comparison, EID-MECT-derived material-specific images showed lower noise levels than TB-DECT and DS-DECT, but slightly higher than that from PCD-CT in I/Gd/Water imaging. For I/Bi/Water imaging, EID-MECT showed a comparable noise level to DS-DECT, and a much lower noise level than TB-DECT and PCD-CT in all material-specific images. For the four-material decomposition task involving I/Gd/Bi/Water, the bismuth-specific image derived from EID-MECT was slightly noisier, but both iodine- and gadolinium-specific images showed much lower noise levels in comparison to PCD-CT. CONCLUSIONS: For the first time, an EID-based MECT system that can simultaneously acquire three x-ray spectra measurements was implemented on a clinical scanner, which demonstrated comparable or better imaging performance than existing DECT and MECT systems. CI - (c) 2021 American Association of Physicists in Medicine. FAU - Ren, Liqiang AU - Ren L AD - Department of Radiology, Mayo Clinic, Rochester, MN, USA. FAU - Allmendinger, Thomas AU - Allmendinger T AD - Siemens Healthineers, Forchheim, Germany. FAU - Halaweish, Ahmed AU - Halaweish A AD - Siemens Healthineers, Forchheim, Germany. FAU - Schmidt, Bernhard AU - Schmidt B AD - Siemens Healthineers, Forchheim, Germany. FAU - Flohr, Thomas AU - Flohr T AD - Siemens Healthineers, Forchheim, Germany. FAU - McCollough, Cynthia H AU - McCollough CH AD - Department of Radiology, Mayo Clinic, Rochester, MN, USA. FAU - Yu, Lifeng AU - Yu L AD - Department of Radiology, Mayo Clinic, Rochester, MN, USA. LA - eng GR - C06 RR018898/RR/NCRR NIH HHS/United States GR - R21 EB024071/EB/NIBIB NIH HHS/United States GR - R01 EB016966/EB/NIBIB NIH HHS/United States GR - C06 RR018898/NH/NIH HHS/United States GR - R21 EB024071/NH/NIH HHS/United States GR - R01 EB016966/NH/NIH HHS/United States PT - Journal Article DEP - 20210729 PL - United States TA - Med Phys JT - Medical physics JID - 0425746 RN - 9679TC07X4 (Iodine) SB - IM MH - *Iodine MH - Phantoms, Imaging MH - *Photons MH - Radiation Dosage MH - Tomography, X-Ray Computed PMC - PMC8455428 MID - NIHMS1728095 OTO - NOTNLM OT - dual-energy CT (DECT) OT - energy-integrating-detector (EID) OT - material decomposition OT - multi-energy CT (MECT) OT - photon-counting-detector CT (PCD-CT) OT - twin-beam design EDAT- 2021/05/15 06:00 MHDA- 2021/09/23 06:00 PMCR- 2021/09/22 CRDT- 2021/05/14 12:30 PHST- 2021/04/09 00:00 [revised] PHST- 2020/05/29 00:00 [received] PHST- 2021/04/30 00:00 [accepted] PHST- 2021/05/15 06:00 [pubmed] PHST- 2021/09/23 06:00 [medline] PHST- 2021/05/14 12:30 [entrez] PHST- 2021/09/22 00:00 [pmc-release] AID - 10.1002/mp.14943 [doi] PST - ppublish SO - Med Phys. 2021 Sep;48(9):4857-4871. doi: 10.1002/mp.14943. Epub 2021 Jul 29.