To compare a contrast agent with high iodine concentration with an iso-osmolar contrast agent for coronary dual-source computed tomography angiography (DS-CTA), and to assess whether the contrast agent characteristics may affect the diagnostic quality of coronary DS-CTA.
Patients were randomized to receive either 80 mL of iodixa:nol-320 (Visipaque, GE Healthcare, Chalfont St. Giles, United Kingdom) or iomeprol-400 (Iomeron, Bracco Imaging SpA, Milan, Italy) at 5 mL/s. Mean, minimum, maximum heart rate, and its variation (max-min) were assessed during calcium scoring scan and coronary DS-CTA. Three off-site readers independently evaluated the image sets in terms of technical adequacy, reasons for inadequacy, vessel visualization, diagnostic confidence (based on a 5-point scale), and arterial contrast opacification in Hounsfield units (HUs).
Ninety-six patients were included in the final evaluation. No significant differences were observed for pre- and postdose heart rate values for iomeron-400 compared with iodixanol-320, and changes in heart rate variation were also not significantly different (−2.3 ± 11.7 vs. −2.5 ± 7.3 bpm, P > 0.1). Contrast measurements in all analyzed vessels were significantly higher for iomeprol-400 (mean, 391.5–441.4 HU) compared with iodixanol-320 (mean, 332.3–365.5 HU, all P ≤ 0.0038). There was no significant difference in qualitative visualization of coronary arteries (mean scores, 4.3–4.5 for iomeprol, 4.1–4.3 for iodixanol, P = 0.15–0.28), or in diagnostic confidence scores. HU were inversely correlated with the number of insufficiently opacified segments (all readers P ≤ 0.0006).
The high-iodine concentration contrast medium iomeprol-400 demonstrated significant benefit for coronary arterial enhancement compared with the iso-osmolar contrast medium iodixanol-320 when administered at identical flow rates and volumes for coronary DS-CTA. In addition, higher enhancement levels were found to be associated with lower numbers of inadequately visualized segments. Finally, observed mean heart rate changes after intravenous contrast injection were generally small during the examination and comparable for both agents.
From the *University Hospital of Munich Großhadern, Department of Radiology, Munich, Germany; †Hospital Niguarda Ca' Granda, Radiologia Sud, Milan, Italy; ‡University Hospital of Mannheim, Department of Radiology, Mannheim, Germany; §Hospital of Padova, Radiologia, Padova, Italy; ¶Hospital San Camillo-Forlanini, Diagnostica per immagini Cardioscienze, Rome, Italy; ∥Hospital Policlinico San Matteo, Radiologia, Pavia, Italy; **Hospital Maggiore Policlinico, Unità Operativa Radiologia, Milan, Italy; ††University Hospital of Erlangen, Department of Radiology, Erlangen, Germany; ‡‡Bracco Imaging, Konstanz, Germany; and §§University Hospital of Messina, UO Diagnostica per Immagini e Radioterapia - Scienze Radiologiche, Messina, Italy.
Received November 3, 2010, and accepted for publication, after revision, January 28, 2011.
Supported by a grant from Bracco Imaging SpA, Milan, Italy.
Reprints: Christoph R. Becker, MD, University Hospital of Munich, Großhadern, Institute for Clinical Radiology, Marchioninistr 15, D- 81377 München, Germany. E-mail: firstname.lastname@example.org.