Dual-energy CT: Lower limits of iodine detection and quantification

Megan C. Jacobsen, Erik N.K. Cressman, Eric P. Tamm, Dodge L. Baluya, Xinhui Duan, Dianna D. Cody, Dawid Schellingerhout, Rick R. Layman

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Background: Assessments of the quantitative limitations among the six commercially available dual-energy (DE) CT acquisition schemes used by major CT manufacturers could aid researchers looking to use iodine quantification as an imaging biomarker. Purpose: To determine the limits of detection and quantification of DE CT in phantoms by comparing rapid peak kilovoltage switching, dual-source, split-filter, and dual-layer detector systems in six different scanners. Materials and Methods: Seven 50-mL iohexol solutions were used, with concentrations of 0.03-2.0 mg iodine per milliliter. The solutions and water sample were scanned five times each in two phantoms (small, 20-cm diameter; large, 30 3 40-cm diameter) with six DE CT systems and a total of 10 peak kilovoltage settings or combinations. Iodine maps were created, and the mean iodine signal in each sample was recorded. The limit of blank (LOB) was defined as the upper limit of the 95% confidence interval of the water sample. The limit of detection (LOD) was defined as the concentration with a 95% chance of having a signal above the LOB. The limit of quantification (LOQ) was defined as the lowest concentration where the coefficient of variation was less than 20%. Results: The LOD range was 0.021-0.26 mg/mL in the small phantom and 0.026-0.55 mg/mL in the large phantom. The LOQ range was 0.07-0.50 mg/mL in the small phantom and 0.20-1.0 mg/mL in the large phantom. The dual-source and rapid peak kilovoltage switching systems had the lowest LODs, and the dual-layer detector systems had the highest LODs. Conclusion: The iodine limit of detection using dual-energy CT systems varied with scanner and phantom size, but all systems depicted iodine in the small and large phantoms at or below 0.3 and 0.5 mg/mL, respectively, and enabled quantification at concentrations of 0.5 and 1.0 mg/mL, respectively.

Original languageEnglish (US)
Pages (from-to)414-419
Number of pages6
JournalRadiology
Volume292
Issue number2
DOIs
StatePublished - Jan 1 2019

Fingerprint

Iodine
Limit of Detection
Iohexol
Water
Biomarkers
Research Personnel
Confidence Intervals

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

Jacobsen, M. C., Cressman, E. N. K., Tamm, E. P., Baluya, D. L., Duan, X., Cody, D. D., ... Layman, R. R. (2019). Dual-energy CT: Lower limits of iodine detection and quantification. Radiology, 292(2), 414-419. https://doi.org/10.1148/radiol.2019182870

Dual-energy CT : Lower limits of iodine detection and quantification. / Jacobsen, Megan C.; Cressman, Erik N.K.; Tamm, Eric P.; Baluya, Dodge L.; Duan, Xinhui; Cody, Dianna D.; Schellingerhout, Dawid; Layman, Rick R.

In: Radiology, Vol. 292, No. 2, 01.01.2019, p. 414-419.

Research output: Contribution to journalArticle

Jacobsen, MC, Cressman, ENK, Tamm, EP, Baluya, DL, Duan, X, Cody, DD, Schellingerhout, D & Layman, RR 2019, 'Dual-energy CT: Lower limits of iodine detection and quantification', Radiology, vol. 292, no. 2, pp. 414-419. https://doi.org/10.1148/radiol.2019182870
Jacobsen MC, Cressman ENK, Tamm EP, Baluya DL, Duan X, Cody DD et al. Dual-energy CT: Lower limits of iodine detection and quantification. Radiology. 2019 Jan 1;292(2):414-419. https://doi.org/10.1148/radiol.2019182870
Jacobsen, Megan C. ; Cressman, Erik N.K. ; Tamm, Eric P. ; Baluya, Dodge L. ; Duan, Xinhui ; Cody, Dianna D. ; Schellingerhout, Dawid ; Layman, Rick R. / Dual-energy CT : Lower limits of iodine detection and quantification. In: Radiology. 2019 ; Vol. 292, No. 2. pp. 414-419.
@article{13f5ef7d9bd74f72a8e2ee11a30b33ca,
title = "Dual-energy CT: Lower limits of iodine detection and quantification",
abstract = "Background: Assessments of the quantitative limitations among the six commercially available dual-energy (DE) CT acquisition schemes used by major CT manufacturers could aid researchers looking to use iodine quantification as an imaging biomarker. Purpose: To determine the limits of detection and quantification of DE CT in phantoms by comparing rapid peak kilovoltage switching, dual-source, split-filter, and dual-layer detector systems in six different scanners. Materials and Methods: Seven 50-mL iohexol solutions were used, with concentrations of 0.03-2.0 mg iodine per milliliter. The solutions and water sample were scanned five times each in two phantoms (small, 20-cm diameter; large, 30 3 40-cm diameter) with six DE CT systems and a total of 10 peak kilovoltage settings or combinations. Iodine maps were created, and the mean iodine signal in each sample was recorded. The limit of blank (LOB) was defined as the upper limit of the 95{\%} confidence interval of the water sample. The limit of detection (LOD) was defined as the concentration with a 95{\%} chance of having a signal above the LOB. The limit of quantification (LOQ) was defined as the lowest concentration where the coefficient of variation was less than 20{\%}. Results: The LOD range was 0.021-0.26 mg/mL in the small phantom and 0.026-0.55 mg/mL in the large phantom. The LOQ range was 0.07-0.50 mg/mL in the small phantom and 0.20-1.0 mg/mL in the large phantom. The dual-source and rapid peak kilovoltage switching systems had the lowest LODs, and the dual-layer detector systems had the highest LODs. Conclusion: The iodine limit of detection using dual-energy CT systems varied with scanner and phantom size, but all systems depicted iodine in the small and large phantoms at or below 0.3 and 0.5 mg/mL, respectively, and enabled quantification at concentrations of 0.5 and 1.0 mg/mL, respectively.",
author = "Jacobsen, {Megan C.} and Cressman, {Erik N.K.} and Tamm, {Eric P.} and Baluya, {Dodge L.} and Xinhui Duan and Cody, {Dianna D.} and Dawid Schellingerhout and Layman, {Rick R.}",
year = "2019",
month = "1",
day = "1",
doi = "10.1148/radiol.2019182870",
language = "English (US)",
volume = "292",
pages = "414--419",
journal = "Radiology",
issn = "0033-8419",
publisher = "Radiological Society of North America Inc.",
number = "2",

}

TY - JOUR

T1 - Dual-energy CT

T2 - Lower limits of iodine detection and quantification

AU - Jacobsen, Megan C.

AU - Cressman, Erik N.K.

AU - Tamm, Eric P.

AU - Baluya, Dodge L.

AU - Duan, Xinhui

AU - Cody, Dianna D.

AU - Schellingerhout, Dawid

AU - Layman, Rick R.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Background: Assessments of the quantitative limitations among the six commercially available dual-energy (DE) CT acquisition schemes used by major CT manufacturers could aid researchers looking to use iodine quantification as an imaging biomarker. Purpose: To determine the limits of detection and quantification of DE CT in phantoms by comparing rapid peak kilovoltage switching, dual-source, split-filter, and dual-layer detector systems in six different scanners. Materials and Methods: Seven 50-mL iohexol solutions were used, with concentrations of 0.03-2.0 mg iodine per milliliter. The solutions and water sample were scanned five times each in two phantoms (small, 20-cm diameter; large, 30 3 40-cm diameter) with six DE CT systems and a total of 10 peak kilovoltage settings or combinations. Iodine maps were created, and the mean iodine signal in each sample was recorded. The limit of blank (LOB) was defined as the upper limit of the 95% confidence interval of the water sample. The limit of detection (LOD) was defined as the concentration with a 95% chance of having a signal above the LOB. The limit of quantification (LOQ) was defined as the lowest concentration where the coefficient of variation was less than 20%. Results: The LOD range was 0.021-0.26 mg/mL in the small phantom and 0.026-0.55 mg/mL in the large phantom. The LOQ range was 0.07-0.50 mg/mL in the small phantom and 0.20-1.0 mg/mL in the large phantom. The dual-source and rapid peak kilovoltage switching systems had the lowest LODs, and the dual-layer detector systems had the highest LODs. Conclusion: The iodine limit of detection using dual-energy CT systems varied with scanner and phantom size, but all systems depicted iodine in the small and large phantoms at or below 0.3 and 0.5 mg/mL, respectively, and enabled quantification at concentrations of 0.5 and 1.0 mg/mL, respectively.

AB - Background: Assessments of the quantitative limitations among the six commercially available dual-energy (DE) CT acquisition schemes used by major CT manufacturers could aid researchers looking to use iodine quantification as an imaging biomarker. Purpose: To determine the limits of detection and quantification of DE CT in phantoms by comparing rapid peak kilovoltage switching, dual-source, split-filter, and dual-layer detector systems in six different scanners. Materials and Methods: Seven 50-mL iohexol solutions were used, with concentrations of 0.03-2.0 mg iodine per milliliter. The solutions and water sample were scanned five times each in two phantoms (small, 20-cm diameter; large, 30 3 40-cm diameter) with six DE CT systems and a total of 10 peak kilovoltage settings or combinations. Iodine maps were created, and the mean iodine signal in each sample was recorded. The limit of blank (LOB) was defined as the upper limit of the 95% confidence interval of the water sample. The limit of detection (LOD) was defined as the concentration with a 95% chance of having a signal above the LOB. The limit of quantification (LOQ) was defined as the lowest concentration where the coefficient of variation was less than 20%. Results: The LOD range was 0.021-0.26 mg/mL in the small phantom and 0.026-0.55 mg/mL in the large phantom. The LOQ range was 0.07-0.50 mg/mL in the small phantom and 0.20-1.0 mg/mL in the large phantom. The dual-source and rapid peak kilovoltage switching systems had the lowest LODs, and the dual-layer detector systems had the highest LODs. Conclusion: The iodine limit of detection using dual-energy CT systems varied with scanner and phantom size, but all systems depicted iodine in the small and large phantoms at or below 0.3 and 0.5 mg/mL, respectively, and enabled quantification at concentrations of 0.5 and 1.0 mg/mL, respectively.

UR - http://www.scopus.com/inward/record.url?scp=85070119197&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070119197&partnerID=8YFLogxK

U2 - 10.1148/radiol.2019182870

DO - 10.1148/radiol.2019182870

M3 - Article

C2 - 31237496

AN - SCOPUS:85070119197

VL - 292

SP - 414

EP - 419

JO - Radiology

JF - Radiology

SN - 0033-8419

IS - 2

ER -