Extrinsic prewarming of iodinated CT contrast media (CM) to body temperature reduces viscosity and injection pressures. However, guideline recommendations on the necessity to prewarm iodinated CM are conflicting. And studies examining the effect of extrinsic warming CM for coronary CTA(CCTA) on clinical adverse events and image quality are lack. Enrolled patients of chest pain or coronary artery disease screening were eligible for this a double-blinded, randomized noninferiority trial, and equally allocated into two group randomly: BBT-CM (basic body temperature) group received 37°C CM; RT-CM (room temperature) group received \~23°C CM. A state-of-the-art individualized CM (iopamidol at 370 mg I/mL) injection protocol was used, based on body weight.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
500
A contrast bolus of iopamidol-370 (370 mg I/ml) (iopamidol injection; Consun Pharmaceutical, China) was injected at a flow rate of 4.5-6 mL/s through an 18-20-gauge intravenous antecubital catheter by using a power injector (Ulrich, Germany). The total dose of iopamidol-370 was approximately 0.9 ml /kg body weight.
Chongqing Emergency Mediacl Centre
Chongqing, Chonqing, China
RECRUITINGVessel Attenuation
Mean attenuation in Hounsfield Units (HU) is based on coronary bifurcation, preferably right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex coronary artery (LCX)). Absolute difference in mean attenuation of coronary vessels between groups was calculated with a two-sided 95% confidence interval of the difference.
Time frame: Expected within one month after the coronary CTA is performed
Allergic or allergiclike reaction
Allergic and allergic-like reactions were identified by evaluating notes within the EMR for elements of such reactions specified in nomenclature from the ACR manual. Allergic reactions were recorded according to symptoms of an immune response to the CM, such as feeling cold urticaria or pruritis.
Time frame: 30 minutes after coronary CTA
Extravasations
The radiology staff recorded an estimate of the volume of extravasated contrast media
Time frame: Expected during the coronary CTA scan.
Objective image quality - Signal-to-noise ratio(SNR)
mean attenuation of vessel divided by the mean SD
Time frame: Within one month after the CT is performed
Objective image quality -Contrast-to-noise ratio(CNR)
mean vascular attenuation minus HU of the vessel, divided by the SD of the attenuation of epicardial fat surrounding left main coronary artery and then divided by image noise
Time frame: Within one month after the CT is performed
CT Dose Index (CTDI)vol
CTDIvol (in mGy) the patient received
Time frame: Expected during the coronary CTA is performed
Physiologic reactions-Urgency desire
Urgency desire is defined in the questionnaire as the sudden and intense ''urge'' or need to urinate and scored 1=Not at all, 2=A little, 3= Moderately, 4=A great deal, and 5=A very great deal.
Time frame: Immediately after CT
Body Mass Index
The formula is BMI = kg/m2 , where kg is a person's weight in kilograms and m2 is their height in metres squared.
Time frame: Right before the scan is performed
Subjective image quality
Rated in consensus on a 5-point Likert scale by two radiologists: 1=excellent (absence of artifacts related to motion or coronary calcification); 2=good (minor artifacts); 3=moderate (considerable artifacts but maintained visualization of the arterial lumen); and 4=poor (non-diagnostic because of severe motion artifacts or severe coronary calcification).
Time frame: Within one month after the CT is performed
Heart rate
Heart rate (beats per minute) is monitor during the coronary CTA.
Time frame: During the coronary CTA.
Flow rate
Flow rate of the contrast media in ml/s.
Time frame: Within one month after the CT is performed
Dose-length product (DLP)
DLP (in mGycm) the patient received
Time frame: Within one month after the CT is performed
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