Related Experiment Video
Updated: Jun 6, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Potentials and limitations of low-concentration contrast medium (150 mg iodine/ml) in CT pulmonary angiography
M R Radon1, M J Kaduthodil, J Jagdish
1Department of diagnostic Imaging, Northern General Hospital, Sheffield, UK.
Aim:
To assess the feasibility of producing diagnostic multidetector computed tomography (MDCT) pulmonary angiography with low iodine concentration contrast media (150 mg iodine/ml) in patients with suspected acute pulmonary embolism.
Materials And Methods:
Ninety-five randomized patients underwent MDCT (64 row) pulmonary angiography with 100ml iopromide either at low concentration (LC) of 150 mg iodine/ml (n=45) or high concentration (HC) of 300 mg iodine/ml (n=50), delivered at the rate of 5 ml/s via a power injector. Two experienced radiologists, blinded to the concentration used, subjectively assessed the diagnostic quality and confidence using a four-point scale [1=poor (not diagnostic), 2=satisfactory, 3=good, 4=excellent]. Attenuation values (in HU) were measured in the main proximal branches of the pulmonary arteries.
Results:
The median diagnostic quality score for both observers was 3.5 (interquartile range 3-4) in the HC group and 2.5 (interquartile range 1.5-3) in the LC group (p<0.01). The median diagnostic confidence score for both observers was 4 (interquartile range 3-4) in the HC group and 3 (interquartile range 1.5-4) in the LC group (p<0.01). Both observers rated examinations as diagnostic in 69% of cases in the LC group, compared with 96% of cases in the HC group. Good interobserver agreement was found in both groups (K value 0.72 in the LC group and 0.73 in the HC). Obesity, poor scan timing, and dilution by venous return of non-opacified blood were the main reasons for a reduction in diagnostic quality of examinations in the LC group.
Conclusion:
Despite a 50% reduction of contrast medium dose in comparison to the standard technique, 150 mg iodine/ml can produce diagnostic MDCT pulmonary angiogram studies in the absence of obesity or high cardiac output and hyper-dynamic pulmonary circulation. Reducing the dose of contrast media would minimize the risk of contrast nephropathy in patients at risk of this complication, particularly those suffering from congestive heart failure in whom intravenous hydration is contraindicated.
Insights
Low iodine concentration contrast media can produce diagnostic multidetector computed tomography pulmonary angiography in select patients. This approach may reduce the risk of contrast nephropathy in at-risk individuals.
Area of Science:
- Radiology
- Medical Imaging
Background:
- Acute pulmonary embolism diagnosis relies on multidetector computed tomography (MDCT) pulmonary angiography.
- Iodine-based contrast media are essential for vascular opacification in MDCT angiography.
- Reducing contrast media volume and concentration is desirable to minimize risks like contrast-induced nephropathy.
Purpose of the Study:
- To evaluate the feasibility of using low iodine concentration (150 mg iodine/ml) contrast media for diagnostic MDCT pulmonary angiography.
- To compare diagnostic quality and confidence of low-concentration versus standard high-concentration contrast media.
Main Methods:
- Ninety-five patients with suspected acute pulmonary embolism underwent 64-row MDCT pulmonary angiography.
- Patients received 100ml of iopromide at either low concentration (150 mg iodine/ml) or high concentration (300 mg iodine/ml).
- Two blinded radiologists assessed diagnostic quality and confidence, and pulmonary artery attenuation was measured.
Main Results:
- Diagnostic quality and confidence scores were significantly lower in the low-concentration group compared to the high-concentration group.
- Examinations were rated as diagnostic in 69% of cases in the low-concentration group versus 96% in the high-concentration group.
- Factors like obesity and scan timing affected diagnostic quality in the low-concentration group.
Conclusions:
- Diagnostic MDCT pulmonary angiography is feasible with 150 mg iodine/ml contrast media in patients without obesity or high cardiac output.
- Lowering contrast media concentration can reduce the risk of contrast nephropathy, especially in high-risk patients like those with congestive heart failure.
More Related Videos
12:15Tissue Preparation Techniques for Contrast-Enhanced Micro Computed Tomography Imaging of Large Mammalian Cardiac Models with Chronic Disease
Published on: February 8, 2022
11:09High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals
Published on: December 16, 2022
Related Concept Videos
01:30Radiological Investigation I: X-ray and CT
01:27Imaging Studies III: Computed Tomography
01:28Imaging Studies for Cardiovascular System V: CT
01:13Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...
01:14Imaging Studies I: CT and MRI
Description of the Procedures
Computed Tomography (CT) scan:
Computed Tomography (CT) scans use X-ray technology to generate detailed images of bones, organs, and tissues. During the scan, the patient lies on a moving table...
01:20Imaging Studies for Cardiovascular System III: X-Ray
Definition and Purpose
An X-ray, or radiograph, is a non-invasive method that uses ionizing radiation to take images of internal structures. It is mainly used in cardiac imaging to examine the heart, lungs, and major blood vessels, aiming to identify abnormalities in the heart's size, shape, and position, such as heart failure, congenital defects, and vascular...