Contrast Media, CT Scans, Gender, Womens Health
Conditions
Keywords
CT, CT Scans, Contrast Media, contrast, gender
Brief summary
A large proportion of radiological CT examinations require the intravenous administration of iodine-containing X-ray contrast medium. According to current guidelines, the amount required for CT examinations in the (portal) venous phase is calculated on the basis of body weight (e.g. 0.2-0.4 g iodine/kg body weight), but a standardized application dose of the contrast agent is often also used. In earlier studies, the investigators found that the iodine contrast in vessels and organs achieved with a standardized amount of contrast agent differs significantly between women and men. On average, women showed around 10% higher iodine contrast than men of the same height and weight. The investigators attribute these differences to physiological, sex-specific differences in blood volume. For example, the blood volume of a woman 175 cm tall and weighing 75 kg is approx. 400 ml less than that of a man of the same height and weight (approx. 4.6 vs. 5.0 l, calculated according to Nadler). Taking blood volume into account, sex was no longer a significant influencing factor in a retrospective cohort (n=274). The investigators would now like to investigate these results in a prospective study. For this purpose, two groups of patients with a clinical indication for a contrast-enhanced CT scan in the venous phase will be compared: 1. control group with regular weight-adjusted (n = 200) 2. study group with dosing according to blood volume (n = 200). The hypothesis is that the application scheme adapted to the blood volume leads to a more homogeneous contrasting of women and men. In order to quantify this effect, the iodine contrast values of both groups will be quantitatively analyzed, taking into account other influencing variables (height, weight). The investigators hope that this approach will reduce or even eliminate the observed sex-specific differences. This would lead to a sex-equal contrast based on an individualized amount of contrast medium.
Interventions
DRUGcontrast media (Imeron 350, active ingredient Iomeprol) volume according to sex-specific blood volume
Calculation of the standardized contrast agent (Imeron 350, active ingredient Iomeprol) quantity (0.35 g iodine/kg) and calculation of the specific blood volume using the established Nadler formula for male and female. Adjustment of the contrast agent according to the ratio of the blood volumes. The amount of saved contrast agent is replaced 1:1 by NaCl.
Sponsors
University Hospital Augsburg
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Presence of a justifying indication for a CT scan of the thorax and abdomen with application of intravenous contrast medium and a start delay corresponding to the portal venous contrast medium phase * Ability to give informed consent, as well as written and verbal consent to participate in the study available
Exclusion criteria
* Cardiorespiratory instability (as assessed by the attending physician) * Age \<18 years * Existing or suspected pregnancy * Known post hepatectomy and/or splenectomy * Lack of current height (in the same inpatient/outpatient hospital stay) or lack of possibility of height measurement * Lack of current daily body weight or inability to measure body weight * Height under 140 cm or over 220 cm * Body weight under 50 kg or over 120 kg * Contraindication to iodine-containing contrast medium (Allergy to contrast media containing iodine, Severe renal insufficiency (eGFR \< 30 ml/min), Hyperthyroidism)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sex-specific contrast difference in the vessels and organs | 1 year | Achieved iodine contrast (Hounsfield units) in vessels and organs |
| Contrasting the organs after adjusting the application dose of the contrast agent to the specific blood volume | 1 year | Achieved iodine contrast (Hounsfield units) in vessels and organs |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Evaluation of whether the adapted blood volume formula according to Nadler can be used to achieve the minimum amount of contrast medium required to ensure sufficient contrast | 1 year | Quantitative measurements of the attenuation of the liver, the portal vein, the aorta, the spleen and the kidneys by placing circular ROIs on CT-series. Mean and standard deviation of CT-values are obtained from contrast enhanced series, iodine maps and virtual non-contrast series. The measurements are performed by blinded physicians using anonymized data on a dedicated workstation. |
| Evaluation of the contrast values achieved that still allow sufficient assessment of the vessels and organs. | 1 year | Quantitative measurements of the attenuation of the liver, the portal vein, the aorta, the spleen and the kidneys by placing circular ROIs on CT-series. Mean and standard deviation of CT-values are obtained from contrast enhanced series, iodine maps and virtual non-contrast series. The measurements are performed by blinded physicians using anonymized data on a dedicated workstation. |
| Comparison of the diagnostic accuracy of DECT/MECT-based imaging of vascular and organ structures. | 1 year | Quantitative measurements of the attenuation of the liver, the portal vein, the aorta, the spleen and the kidneys by placing circular ROIs on CT-series. Mean and standard deviation of CT-values are obtained from contrast enhanced series, iodine maps and virtual non-contrast series. The measurements are performed by blinded physicians using anonymized data on a dedicated workstation. |
Countries
Germany
Contacts
Primary ContactClaudia Wollny, Dr.
Outcome results
None listed