Relationship Between Contrast Media Volume and Tube Voltage in CT for Optimal Liver Enhancement, Based on Body Weight.

NCT03735706 | Completed DMC

• 1 other identifier: NL66971.068.18
• Study Type: interventional
• Target: 245
• Locations: 1 country
• Sites: 1

Brief Summary

Computed Tomography (CT) is widely used in abdominal imaging for a variety of indications. Contrast media (CM) is used to enhance vascular structures and organ parenchyma. Attenuation of the liver makes it possible to recognize hypo- and hypervascular lesions, which are often invisible on unenhanced CT images. Lesions can only be detected in case they are large enough and the contrast with the background is high enough. Heiken et al. showed already in 1995 that a difference in Hounsfield Units (HU) of at least 50 HU is needed to be able to recognize liver lesions \[1\]. On the other hand, patients should not receive more CM than necessarily, because of possible underlying physiological effects \[2-4\]. Although there has been some controversy about this recently, there is no need to give patients more CM than needed, because of increased costs, no quality improvement and their might still be a relationship with contrast induced nephropathy (CIN) \[5\]. Recent publications suggested individualization of injection protocols that can be based on either total body weight (TBW) or lean body weight (LBW) \[6-9\]. In the investigators department an injection protocol based on TBW is currently used. Besides the CM injection parameters, scanner parameters are of influence on the attenuation as well. Because of recent technical developments it became possible to reach a good image quality (IQ) at lower tube voltages \[10\]. When the x-ray output comes closer to the 33 keV k-edge of Iodine, attenuation increases. In short, decreasing the tube voltage increases the attenuation of iodine. Scanning at a lower tube voltage therefore gives rise to even lower CM volumes. Lastly, it would be revolutionary to accomplish a liver enhancement that is homogenous, sufficient for lesion detection and comparable between patients and in the same patients, regardless of weight and scanner settings used.

Conditions

Radiation; Contrast Media; Liver; Body Weight

Keywords

Radiation; Contrast media; Liver; Body Weight

Outcome Measures

Primary Outcomes (1)

• A liver attenuation (Δ HU)

  The attenuation of the liver parenchyma as assessed by measuring the Hounsfield units (HU) of the liver parenchyma in an unenhanced CT scan and a scan in portal venous phase. The difference between the enhanced and unenhanced CT scan is the Δ HU. It is expected that scans in all groups have a Δ HU of at least 50 HU, which is considered sufficient. Therefore it is a non-inferiority outcome.

  Measurement for each scan is performed withing 1 month after the scan.

Secondary Outcomes (14)

• Objective image quality - signal-to-noise and contrast-to-noise ratio

  Measurement for each scan is performed within 1 month after the scan.

• Subjective image quality - assessed with a 5-point Likert scale

  Measurement for each scan is performed within 1 month after the scan.

• Radiation dose

  Measurement for each scan is performed within 1 month after the scan.

• Weight

  Directly prior to the scan it is measured and data is collected within one month after the scan.

• Height (in m)

  Directly prior to the scan it is measured and data is collected within one month after the scan.

Study Arms (4)

Control group - 120 kV - 0.521 g I/kg

ACTIVE COMPARATOR

Weight is measured prior to the scan. Before performing the contrast enhanced CT scan(s), an unenhanced slice through the liver, at the level of the portal vein, is performed. Contrast media injection protocol with a standard dosing factor of 0.521 g I/kg of TBW and a tube voltage of 120 kV. The intervention is the application of a standard contrast media volume and a standard tube voltage of 120 kV.

Radiation: Unenhanced slice; Diagnostic Test: Weight

90 kV - 0.521 g I/kg

EXPERIMENTAL

Weight is measured prior to the scan. Before performing the contrast enhanced CT scan(s), an unenhanced slice through the liver, at the level of the portal vein, is performed. Contrast media injection protocol with a standard dosing factor of 0.521 g I/kg of TBW. A radiation dose reduction from 120 to 90 kV. The intervention is a change in tube voltage to 90 kV, compared to group 1. The other intervention; contrast media volume, is unchanged compared to group 1.

Radiation: Radiation dose reduction; Radiation: Unenhanced slice; Diagnostic Test: Weight

100 kV - 0.417 g I/kg

EXPERIMENTAL

Weight is measured prior to the scan. Before performing the contrast enhanced CT scan(s), an unenhanced slice through the liver, at the level of the portal vein, is performed. Contrast media volume reduction with a dosing factor of 0.417 g I/kg of TBW. A radiation dose reduction from 120 to 100 kV compared to group 1. The intervention is a change in tube voltage to 100 kV, compared to group 1. The other intervention is a change in contrast media volume, which is adapted to the tube voltage used and therefore lowered to 0.417 g I/kg.

Radiation: Radiation dose reduction; Other: Contrast media volume reduction; Radiation: Unenhanced slice; Diagnostic Test: Weight

90 kV - 0.365 g I/kg

EXPERIMENTAL

Weight is measured prior to the scan. Before performing the contrast enhanced CT scan(s), an unenhanced slice through the liver, at the level of the portal vein, is performed. Contrast media volume reduction with a dosing factor of 0.365 g I/kg of TBW. A radiation dose reduction from 120 to 90 kV compared to group 1. The intervention is a change in tube voltage to 90 kV, compared to group 1. The other intervention is a change in contrast media volume, which is adapted to the tube voltage used and therefore lowered to 0.365 g I/kg.

Radiation: Radiation dose reduction; Other: Contrast media volume reduction; Radiation: Unenhanced slice; Diagnostic Test: Weight

Interventions

Radiation dose reduction RADIATION

The radiation dose is is different between groups

100 kV - 0.417 g I/kg; 90 kV - 0.365 g I/kg; 90 kV - 0.521 g I/kg

Contrast media volume reduction OTHER

Contrast media volume is different between groups

100 kV - 0.417 g I/kg; 90 kV - 0.365 g I/kg

Unenhanced slice RADIATION

One unenhanced slice at the level of the portal vein will be added to the protocol before administration of contrast media. It will only take a minute to perform this extra slice. The patient does not have to visit the department a second time and no (extra) contrast is needed for this slice.

100 kV - 0.417 g I/kg; 90 kV - 0.365 g I/kg; 90 kV - 0.521 g I/kg; Control group - 120 kV - 0.521 g I/kg

Weight DIAGNOSTIC_TEST

A weighing scale is used to measure a patients body weight right before the scan.

100 kV - 0.417 g I/kg; 90 kV - 0.365 g I/kg; 90 kV - 0.521 g I/kg; Control group - 120 kV - 0.521 g I/kg

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients referred for abdominal CT in portal venous phase
• Patients ≥ 18 years and competent to sign an informed consent

You may not qualify if:

• Hemodynamic instability
• Pregnancy
• Renal insufficiency (defined as Glomerular Filtration Rate (GFR) \< 30 mL/min/1,73m2 \[Odin protocol 004720\])
• Iodine allergy (Odin protocol 022199)
• Age \<18 years
• Absence of informed consent

Sponsors & Collaborators

• Maastricht University Medical Center: lead

Study Sites (1)

MUMC+

Maastricht, Limburg, 6224 CG, Netherlands

Location

MeSH Terms

Conditions

Body Weight

Condition Hierarchy (Ancestors)

Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Joachim Wildberger, Professor

  Maastricht University Medical Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Masking Details: A computer random number generator prepares the randomization schedule in a 1:1:1:1 manner, which is balanced randomization. Stratification is performed, based on age (\< 60 and ≥ 60 years) and weight \< 75 and ≥ 75 kg). Variable block randomization will distribute patients equally over time. The blinding and randomization process will be conducted by Clinical Trial Centre Maastricht (CTCM, www.CTCM.nl) with a randomization program (ALEA) designed for usage of different techniques.
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: randomized controlled trial with 4 study arms.

Study Record Dates

• First Submitted: October 31, 2018
• First Posted: November 8, 2018
• Study Start: December 13, 2018
• Primary Completion: June 26, 2019
• Study Completion: June 26, 2019
• Last Updated: February 10, 2020

Record last verified: 2020-02

Locations

NL (1)