Coronary CT angiography using low concentrated contrast media injected with high flow rates: Feasible in clinical practice.
OBJECTIVE
Aim of this study was to test the hypothesis that peak injection pressures and image quality using low concentrated contrast media (CM) (240 mg/mL) injected with high flow rates will be comparable to a standard injection protocol (CM: 300 mg/mL) in coronary computed tomographic angiography (CCTA).


METHODS
One hundred consecutive patients were scanned on a 2nd generation dual-source CT scanner. Group 1 (n=50) received prewarmed Iopromide 240 mg/mL at an injection rate of 9 mL/s, followed by a saline chaser. Group 2 (n=50) received the standard injection protocol: prewarmed Iopromide 300 mg/mL; flow rate: 7.2 mL/s. For both protocols, the iodine delivery rate (IDR, 2.16 gI/s) and the total iodine load (22.5 gI) were kept identical. Injection pressure (psi) was continuously monitored by a data acquisition program. Contrast enhancement was measured in the thoracic aorta and all proximal and distal coronary segments. Subjective and objective image quality was evaluated between both groups.


RESULTS
No significant differences in peak injection pressures were found between both CM groups (121 ± 5.6 psi vs. 120 ± 5.3 psi, p=0.54). Flow rates of 9 mL/s were safely injected without any complications. No significant differences in contrast-to-noise ratio, signal-to-noise ratio and subjective image quality were found (all p>0.05). No significant differences in attenuation levels were found in the thoracic aorta and all segments of the coronary arteries (all p>0.05).


CONCLUSIONS
Usage of low iodine concentration CM and injection with high flow rates is feasible. High flow rates (9 mL/s) of Iopromide 240 were safely injected without complications and should not be considered a drawback in clinical practice. No significant differences in peak pressure and image quality were found. This creates a doorway towards applicability of a broad variety in flow rates and IDRs and subsequently more individually tailored injection protocols.
Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands. Electronic address: m.das@mumc.nl.
Casper
C
Mihl
Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
Madeleine
M
Kok
Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
Joachim E
JE
Wildberger
CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, The Netherlands.
Sibel
S
Altintas
Department of Radiology, Maastricht University Medical Center, The Netherlands.
David
D
Labus
Department of Radiology, Maastricht University Medical Center, The Netherlands.
Estelle C
EC
Nijssen
Department of Radiology, Maastricht University Medical Center, The Netherlands.
Babs M F
BM
Hendriks
Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, The Netherlands.
Bas L J H
BL
Kietselaer
Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
Marco
M
Das
D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007455:Iodine / Q000008:administration & dosage*; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods
D003287:Contrast Media; D007472:Iohexol; C038192:iopromide; D007455:Iodine
Cardiac imaging technique; Computed tomography; Contrast media; Diagnostic imaging; Flow injection analysis