Individually Body Weight–Adapted Contrast Media Application in Computed Tomography Imaging of the Liver at 90 kVp

Martens, Bibi; Hendriks, Babs M. F.; Eijsvoogel, Nienke G.; Wildberger, Joachim E.; Mihl, Casper

doi:10.1097/rli.0000000000000525

Cited by 23 publications

(37 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It typically consists of a multiphase acquisition including a noncontrast, arterial, and delayed phase of enhancement. 5 Some recent studies suggested the use of low tube voltages for singleenergy CTA (low-kV SEI) 6 because low-kV SEI increases the CT attenuation and contrast-to-noise ratio (CNR) in structures containing iodine 7 and is associated with less radiation dose. 8,9 With the introduction of dual-energy CT (DECT), further alternatives to improve iodine attenuation and to decrease radiation dose have become clinically available.…”

mentioning

confidence: 99%

Dual-Energy Low-keV or Single-Energy Low-kV CT for Endoleak Detection?

et al. 2019

View full text Add to dashboard Cite

The aim of this study was to compare image quality, conspicuity, and endoleak detection between single-energy low-kV images (SEIs) and dual-energy low-keV virtual monoenergetic images (VMIs+) in computed tomography angiography of the aorta after endovascular repair. MATERIALS AND METHODS: An abdominal aortic aneurysm phantom simulating 36 endoleaks (2 densities; diameters: 2, 4, and 6 mm) in a medium-and large-sized patient was used. Each size was scanned using single-energy at 80 kVp (A) and 100 kVp (B), and dual-energy at 80/Sn150kVp for the medium (C) and 90/Sn150kVp for the large size (D). VMIs+ at 40 keV and 50 keV were reconstructed from protocols C and D. Radiation dose was 3 mGy for the medium and 6 mGy for the large size. Objective image quality and normalized noise power spectrum were determined. Subjective image quality, conspicuity, and sensitivity for endoleaks were independently assessed by 6 radiologists. Sensitivity was compared using Marascuilo procedure and Fisher exact test. Conspicuities were compared using Wilcoxon-matched pairs test, analysis of variance, and Tukey test. RESULTS: The contrast-to-noise-ratio of the aorta was significantly higher for VMI+ compared with SEI (P < 0.001). Noise power spectrum showed a higher noise magnitude and coarser texture in VMI+. Subjective image quality and overall conspicuity was lower for VMI+ compared with SEI (P < 0.05). Sensitivity for endoleaks was overall higher in the medium phantom for SEI (60.9% for A, 62.2% for B) compared with VMI+ (54.2% for C, 49.3% for D) with significant differences between protocols B and D (P < 0.05). In the large phantom, there was no significant difference in sensitivity among protocols (P = 0.79), with highest rates for protocols B (31.4%) and C (31.7%). CONCLUSIONS: Our study indicates that low-keV VMI+ results in improved contrast-to-noise-ratio of the aorta, whereas noise properties, subjective image quality, conspicuity, and sensitivity for endoleaks were overall superior for SEI.

show abstract

mentioning

confidence: 99%

Dual-Energy Low-keV or Single-Energy Low-kV CT for Endoleak Detection?

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Future prospective studies could investigate the impact of personalised dosing on liver enhancement and diagnostic properties, which should also take tube voltage into account [14]. Many studies already investigated the potential of low kVp settings (e.g., 70, 80, and 100 kVp) [2,14,[29][30][31][32] or virtual monochromatic imaging with low kV reconstruction [33][34][35][36][37] in combination with a reduced amount of injected iodine in a more lightweight population using CT angiography protocols, wherein only the signal during the first pass of contrast media is crucial [29]. However, this has not properly been investigated for abdominal protocols yet, which rely on longer contrast media boluses to provide homogeneous enhancement of parenchymal organs, such as the liver.…”

Section: Discussionmentioning

confidence: 99%

“…A personalised protocol for iodine dosing should be preferred to the standard fixed-contrast protocol [13]. In this respect, body-weight-adapted contrast injection protocols have proven successful in achieving a more homogeneous enhancement of vascular structures and liver parenchyma in patients [8,[14][15][16][17]. However, total body weight (TBW) is not the only relevant body-size-related factor; lean body weight (LBW) and body mass index (BMI) might also be important.…”

Section: Introductionmentioning

confidence: 99%

Towards Personalised Contrast Injection: Artificial-Intelligence-Derived Body Composition and Liver Enhancement in Computed Tomography

Jong

Veldhuis

Wessels

et al. 2021

JPM

View full text Add to dashboard Cite

In contrast-enhanced computed tomography, total body weight adapted contrast injection protocols have proven successful in achieving a homogeneous enhancement of vascular structures and liver parenchyma. However, because solid organs have greater perfusion than adipose tissue, the lean body weight (fat-free mass) rather than the total body weight is theorised to cause even more homogeneous enhancement. We included 102 consecutive patients who underwent a multiphase abdominal computed tomography between March 2016 and October 2019. Patients received contrast media (300 mgI/mL) according to bodyweight categories. Using regions of interest, we measured the Hounsfield unit (HU) increase in liver attenuation from unenhanced to contrast-enhanced computed tomography. Furthermore, subjective image quality was graded using a four-point Likert scale. An artificial intelligence algorithm automatically segmented and determined the body compositions and calculated the percentages of lean body weight. The hepatic enhancements were adjusted for iodine dose and iodine dose per total body weight, as well as percentage lean body weight. The associations between enhancement and total body weight, body mass index, and lean body weight were analysed using linear regression. Patients had a median age of 68 years (IQR: 58–74), a total body weight of 81 kg (IQR: 73 – 90), a body mass index of 26 kg/m2 (SD: ±4.2), and a lean body weight percentage of 50% (IQR: 36 – 55). Mean liver enhancements in the portal venous phase were 61 ± 12 HU (≤ 70 kg), 53 ± 10 HU (70 – 90 kg), and 53 ± 7 HU (≥ 90 kg). The majority (93%) of scans were rated as good or excellent. Regression analysis showed significant correlations between liver enhancement corrected for injected total iodine and total body weight (r = 0.53; p < 0.001) and between liver enhancement corrected for lean body weight and the percentage of lean body weight (r = 0.73; p < 0.001). Most benefits from personalising iodine injection using %LBW additive to total body weight would be achieved in patients under 90 kg. Liver enhancement is more strongly associated with the percentage of lean body weight than with the total body weight or body mass index. The observed variation in liver enhancement might be reduced by a personalised injection based on the artificial-intelligence-determined percentage of lean body weight.

show abstract

“…The methods described above 22,24 are applicable for abdominal CT protocols with a single tube voltage (120 kV) only; however, recent approaches aim toward abdominal CT scanning with lower tube voltages. 36 In addition, these methods do not allow taking alternative scan lengths and body regions into account. In contrast, our approach allows for radiation dose assessments from any scanned body region, scan length, and CT protocol.…”

Section: Discussionmentioning

confidence: 99%

Radiation Dose to the Fetus From Computed Tomography of Pregnant Patients—Development and Validation of a Web-Based Tool

et al. 2020

View full text Add to dashboard Cite

OBJECTIVE Estimations of radiation dose absorbed by the fetus from computed tomography (CT) in pregnant patients is mandatory, but currently available methods are not feasible in clinical routine. The aims of this study were to develop and validate a tool for assessment of fetal dose from CT of pregnant patients and to develop a user-friendly web interface for fast fetal dose calculations. METHODS In the first study part, 750 Monte Carlo (MC) simulations were performed on phantoms representing pregnant patients at various gestational stages. The MC code simulating vendor-independent dose distributions was validated against CT dose index (CTDI) measurements performed on CT scanners of 2 vendors. The volume CTDI-normalized fetal dose values from MC simulations were used for developing the computational algorithm enabling fetal dose assessments from CT of various body regions at different exposure settings. In the institutional review board-approved second part, the algorithm was validated against patient-specific MC simulations performed on CT data of 29 pregnant patients (gestational ages 8-35 weeks) who underwent CT. Furthermore, the tool was compared with a commercially available software. A user-friendly web-based interface for fetal dose calculations was created. RESULTS Weighted CTDI values obtained from MC simulations were in excellent agreement with measurements performed on the 2 CT systems (average error, 4%). The median fetal dose from abdominal CT in pregnant patients was 2.7 mGy, showing moderate correlation with maternal perimeter (r = 0.69). The algorithm provided accurate estimates of fetal doses (average error, 11%), being more accurate than the commercially available tool. The web-based interface (www.fetaldose.org) enabling vendor-independent calculations of fetal doses from CT requires the input of gestational age, volume CTDI, tube voltage, and scan region. CON-CLUSIONS A tool for fetal dose assessments from CT of pregnant patients was developed and validated being freely available on a user-friendly web interface.

show abstract

Individually Body Weight–Adapted Contrast Media Application in Computed Tomography Imaging of the Liver at 90 kVp

Cited by 23 publications

References 41 publications

Dual-Energy Low-keV or Single-Energy Low-kV CT for Endoleak Detection?

Dual-Energy Low-keV or Single-Energy Low-kV CT for Endoleak Detection?

Towards Personalised Contrast Injection: Artificial-Intelligence-Derived Body Composition and Liver Enhancement in Computed Tomography

Radiation Dose to the Fetus From Computed Tomography of Pregnant Patients—Development and Validation of a Web-Based Tool

Contact Info

Product

Resources

About