Radiation Dose Reduction in Contrast-Enhanced Abdominal CT: Comparison of Photon-Counting Detector CT with 2nd Generation Dual-Source Dual-Energy CT in an oncologic cohort

Robin Wrazidlo; Lukas Walder; Arne Estler; Ralf Gutjahr; Bernhard Schmidt; Sebastian Faby; Jan Fritz; Konstantin Nikolaou; Marius Horger; Florian Hagen

doi:10.1016/j.acra.2022.05.021

Radiation Dose Reduction in Contrast-Enhanced Abdominal CT: Comparison of Photon-Counting Detector CT with 2nd Generation Dual-Source Dual-Energy CT in an oncologic cohort

Acad Radiol. 2023 May;30(5):855-862. doi: 10.1016/j.acra.2022.05.021. Epub 2022 Jun 24.

Authors

Affiliations

¹ Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, 72076 Tübingen, Germany (R.W., L.W., A.E., K.N., M.H., F.H.); Siemens Healthcare GmbH, 91052 Erlangen, Germany (R.G., B.S., S.F.); NYU Grossman School of Medicine, Department of Radiology, New York, NY 10016, USA (J.F.).
² Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, 72076 Tübingen, Germany (R.W., L.W., A.E., K.N., M.H., F.H.); Siemens Healthcare GmbH, 91052 Erlangen, Germany (R.G., B.S., S.F.); NYU Grossman School of Medicine, Department of Radiology, New York, NY 10016, USA (J.F.). Electronic address: [email protected].

PMID: 35760710
DOI: 10.1016/j.acra.2022.05.021

Abstract

Rational and objectives: Comparison of radiation dose and image quality in routine abdominal and pelvic contrast-enhanced computed tomography (CECT) between a photon-counting detector CT (PCD-CT) and a dual energy dual source CT (DSCT).

Materials and methods: 70 oncologic patients (mean age 66 ± 12 years, 29 females) were prospectively enrolled between November 2021 and February 2022. Abdominal CECT were clinically indicated and performed first on a 2^nd-generation DSCT and at follow-up on a 1^st-generation dual-source PCD-CT. The same contrast media (Imeron 350, Bracco imaging) and pump protocol was used for both scans. For both scanners, polychromatic images were reconstructed with 3mm slice thickness and comparable kernel (I30f[DSCT] and Br40f[PCD-CT]); for PCD-CT data from all counted events above the lowest energy threshold at 20 keV ("T3D") were used. Results were compared in terms of radiation dose metrics of CT dose index (CTDI_vol), dose length product (DLP) and size-specific dose estimation (SSDE), objective and subjective measurements of image quality were scored by two emergency radiologists including lesion conspicuity.

Results: Median time interval between the scans was 4 months (IQR: 3-6). CNR_vessel and SNR_vessel of T3D reconstructions from PCD-CT were significantly higher than those of DSCT (all, p < 0.05). Qualitative image noise analysis from PCD-CT and DSCT yielded a mean of 4 each. Lesion conspicuity was rated significantly higher in PCD-CT (Q3 strength) compared to DSCT images. CTDI, DLP and SSDE mean values for PCD-CT and DSCT were 7.98 ± 2.56 mGy vs. 14.11 ± 2.92 mGy, 393.13 ± 153.55 mGy*cm vs. 693.61 ± 185.76 mGy*cm and 9.98 ± 2.41 vs. 14.63 ± 1.63, respectively, translating to a dose reduction of around 32% (SSDE).

Conclusion: PCD-CT enables oncologic abdominal CT with a significantly reduced dose while keeping image quality similar to 2^nd-generation DSCT.

Keywords: Dual source dual energy CT; Image quality; Photon counting CT; Radiation dose.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Abdomen* / diagnostic imaging
Aged
Aged, 80 and over
Drug Tapering*
Female
Humans
Male
Middle Aged
Radiation Dosage*
Radiographic Image Enhancement
Tomography, X-Ray* / methods