Effect of Contrast Media Formulation on Computed Tomography Angiographic Contrast Enhancement

Abstract

The characteristics of contrast media formulation (mgI/ml, osmolarity, and viscosity) are generally not considered important in computed tomography (CT) angiography in animals. The purpose of this study was to assess the contrast effect in CT angiography as a function of contrast media formulation, with a constant iodine dose. The contrast effects of three contrast media with different iodine concentrations were compared by administering identical iodine dosages (mgI/kg). The contrast effects of the three contrast media differed, and the area under the time-attenuation curve of iohexol 350 mgI/ml, which had the highest iodine concentration, was the lowest. It was hypothesized that the contrast effect of a contrast medium decreases with higher iodine concentration because of the high amount of residual iodine present in the circulatory system from the injection site to the portion immediately before the great vessels. In addition, the influence of osmotic dilution on contrast media with high osmolarity was also considered. In conclusion, the contrast effect varies with different contrast media formulations, even when the same iodine dosage is administered.

Diagnostic utility of computed tomography imaging in equine intracranial conditions

“…dosage and route of injection of the contrast medium, as well as blood pressure and recumbency of the patient) which may limit the availability and distribution of the i.v. iodinated contrast administered in horses (Kishimoto et al . 2008; Pollard et al .…”

Dynamic computed tomographic determination of scan delay for use in performing cardiac angiography in clinically normal dogs

“…11 In veterinary medicine, a few CT protocols have been evaluated for contrast enhancement of the caudal vena cava, abdominal aorta, and pulmonary artery. 8,10 However, to the authors' knowledge, a protocol for performing cardiac CT angiography has not been reported for veterinary species. A method is needed to help discriminate intraand extracardiac structures in dogs better than is achieved with echocardiography.…”

“…This profile reflects the rapid distribution of contrast medium away from the cardiovascular system. 10 Consequently, nonuniform cardiovascular enhancement occurs during image acquisition when a uniphasic injection protocol is used. 10 A modified version of the uniphasic injection protocol, the multiphasic approach, includes flushing with saline (0.9% NaCl) solution or diluted contrast…”

“…(Am J Vet Res 2015;76:694-701) circulation, age, and body weight), and CT scanning factors (eg, scan duration, equipment used [multidetector-vs monodetector-row CT], scan delay [interval from initiation of contrast medium injection to image acquisition], and method used to control the timing of contrast medium arrival at the ROI [test bolus vs bolus-tracking method]). [8][9][10][11] In human medicine, protocols for contrast medium injection have been evaluated for use in cardiac CT angiography. With a traditional uniphasic injection protocol, the resulting cardiac enhancement profile consists of a single peak in the degree of enhancement within the ROI followed by a rapid decrease once injection is complete.…”

Use of larger species such as dog and pig as model systems to study cardiac disease

“…Coronary angiography has classically been performed with X-ray imaging after contrast injection, and clinical methods can be used in large animals. Coronary imaging may also be done with computed-tomography (CT) angiography [34] as well as magnetic resonance angiography [35]. This may also be possible in small mammals, using microCT [36] and small bore, high magnetic field MR scanners [37], but these methods are still being developed.…”