Feasibility of Low-volume Injections of Contrast Material with a Body Weight–Adapted Iodine-Dose Protocol in 320-Detector Row Coronary CT Angiography

doi:10.1016/j.acra.2009.09.010

Academic Radiology

Volume 17, Issue 2, February 2010, Pages 207-211

https://doi.org/10.1016/j.acra.2009.09.010 Get rights and content

Rationale and Objectives

To investigate the feasibility of low-volume injections of contrast material with a body weight-adapted iodine-dose protocol in computed tomography coronary angiography (CTCA) using a 320-detector row scanner.

Materials and Methods

Ninety-eight patients who underwent CTCA in a single heartbeat with electrocardiogram-gating were divided into two groups, receiving 0.8 mL/kg of contrast material injected at a fixed duration of 12 seconds (A; n = 48) or 0.7 mL/kg of contrast material injected at a fixed duration of 10 seconds (B; n = 50); all patients then received 20 mL of saline. Contrast densities were assessed for the ascending aorta, left ventricle, right coronary artery (RCA), and left main coronary artery (LMA).

Results

The mean flow rate was 4.00 ± 0.56 mL/second in group A and 4.06 ± 0.57 mL/second in group B (P = .51). There were no significant differences in the mean enhancement values of the ascending aorta, LMA and proximal RCA between the two groups. Also, there was no significant difference between the mean enhancement values at the three different levels of the RCA (proximal, middle, and distal segments) (group A; P = .27, group B; P = .07).

Conclusion

The use of 0.7 mL/kg of contrast material injected at a fixed duration of 10 seconds was feasible for CTCA using 320-detector row CT, with a sufficient and reliable contrast enhancement in the ascending aorta and coronary artery.

Section snippets

Patients

Initially, 106 patients who were scheduled to undergo 320-detector row CTCA were recruited in this study. Patients who had previous allergic reaction to iodinated contrast material, severe heart failure, valvular heart disease, or elevated serum creatinine level (>1.5 mg/dL) were excluded, along with women who were potentially pregnant. Patients were referred because of suspected coronary artery disease (CAD) (n = 92) based on the following symptoms such as dyspnea (n = 11), atypical chest pain

Results

CT was successfully performed without complications on all 98 patients, of whom 30 were smokers (31%), 23 had diabetes (23%), 24 had a positive family history for CAD (24%), 32 had dyslipidemia (33%), and 49 were hypertensive (50%). CTCA revealed significant coronary artery stenosis (lumen obstruction of ≥50%) in 24 patients (24%).

All the examinations were performed within a single heartbeat with electrocardiogram-gating. Forty-one of the 98 patients were imaged with a dose modulation, and the

Discussion

This is the first study to investigate the feasibility of low-volume injections of contrast material with a body weight–adapted iodine-dose protocol in 320-detector row CTCA. The use of 0.7 mL/kg of contrast material injected at 10 seconds resulted in sufficient and steady enhancement in the ascending aorta and coronary artery.

In CTCA, high and consistent vascular enhancement is a prerequisite for sufficient evaluation 5, 6, 7, 8, and an optimal enhancement value in the coronary arteries is

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Our objective was to compare the image quality of coronary CT angiography reconstructed with super-resolution deep learning reconstruction (SR-DLR) and with hybrid iterative reconstruction (IR) images.
This retrospective study included 100 patients who underwent coronary CT angiography using a 320-detector-row CT scanner. The CT images were reconstructed with hybrid IR and SR-DLR. The standard deviation of the CT number was recorded and the CT attenuation profile across the left main coronary artery was generated to calculate the contrast-to-noise ratio (CNR) and measure the edge rise slope (ERS). Overall image quality was evaluated and plaque detectability was assessed on a 4-point scale (1 = poor, 4 = excellent). For reference, invasive coronary angiography of 14 patients was used.
The mean image noise on SR-DLR was significantly lower than on hybrid IR images (15.6 vs 22.9 HU; p < 0.01). The mean CNR was significantly higher and the ERS was steeper on SR-DLR- compared to hybrid IR images (CNR: 32.4 vs 20.4, p < 0.01; ERS: 300.0 vs 198.2 HU/mm, p < 0.01). The image quality score was better on SR-DLR- than on hybrid IR images (3.6 vs 3.1; p < 0.01). SR-DLR increased the detectability of plaques with < 50% stenosis (p < 0.01).
SR-DLR was superior to hybrid IR with respect to the image noise, the sharpness of coronary artery margins, and plaque detectability.
Use of low tube voltage and low contrast agent concentration yields good image quality for aortic CT angiography
2016, Clinical Radiology
Citation Excerpt :
A number of authors have attempted to decrease exposure to radiation and/or contrast agents during CTA. Approaches targeting the amount of iodine contrast agent, body volume area, BMI, and tube voltage have been proposed.8–11 In addition, protocols for CTA of various body parts were developed, with reduced radiation and contrast agent doses.4,6,10,12–20
To evaluate the impact of a “double-low“ imaging protocol (low tube voltage and low contrast agent concentration) on image quality and radiation dose for aortic computed tomography (CT) angiography (CTA).
This was a prospective study of 72 patients undergoing aortic CTA. They were randomised to the double-low and conventional CT (control) groups (n=36/group). Axial imaging was performed in the study group, and control patients were scanned with the conventional protocol. Double-low parameters were: 80–100 kV, 200 mAs, 128×0.625 collimation, 1-mm section thickness, 0.5-mm increments, 300 mm field of view (FOV), iohexol (300 mg iodine/ml, 1–1.5 ml/kg, injected at 4–5 ml/s). Control CT parameters were: 120 kV, 200–300 mAs, iopamidol (370 mg iodine/ml; 1–1.5 ml/kg, injected at 4–5 ml/s); the remaining parameters were the same as in the double-low group.
Image noise and quality scores of the double-low and control groups were 15.05±1.53 versus 14.67±1.53 and 3.52±0.51 versus 3.44±0.5 (both p>0.05), respectively. Radiation dose was 56% lower in the double-low group compared to control patients (6.76±1.08 versus 15.48±1.01 mSv, p<0.001). Iodine intake per-capita in the double-low group was 18% lower compared to the control group (300.25±7.2 versus 367.86±5.54 mgI/kg, p<0.001).
The “double-low” technique for aortic CTA significantly reduced the doses of radiation and iodine contrast agent, while maintaining good image quality.
Usefulness of Intraprocedural Coronary Computed Tomographic Angiography during Intervention for Chronic Total Coronary Occlusion
2016, American Journal of Cardiology
Citation Excerpt :
When contrast injection was used, the diluted contrast was used and the actual contrast volumes required by the system was very minimal (mean volume, 1.1 ml). Selective intracoronary injection of the dilated contrast and the shorter scan time of the 640 multislice CT scanner applying double-slice technology allowed the use of smaller volumes.16,25 This study had limitations.
Although intraprocedural coronary computed tomographic angiography (CCTA) allows for scanning during intervention without relocation of the patient, studies have yet to report on its use during chronic total occlusion (CTO) intervention. Therefore, we investigated the role of CCTA during CTO intervention, particularly whether CCTA could be used to evaluate the location of guidewires. A total of 61 patients scheduled for elective CTO intervention were consecutively enrolled and underwent CCTA and on-site analyses during intervention. Transverse axial and the curved multiplanar images in a 360-degree view were interactively used together to identify the location of guidewires, along with the adjustment of window condition. Intracoronary contrast injection was used for specific cases requiring enhancement of the distal part of the CTO. Most CCTAs were performed to confirm the location of a single guidewire; CCTA was also performed to evaluate parallel (3 patients) or retrograde wires (5 patients). The initial identification rate for guidewire location was 56% with immediate transaxial images, but it significantly increased to 87% after interactive on-site uses of the curved multiplanar images (p <0.001). Cases in which guidewire location could be predicted with CCTA evaluation show a numerically higher success rate than those that could not (83% vs 63%) but not statistical significance (p = 0.174). The mean time for CCTA evaluation and mean radiation dose were 8.6 minutes and 2.9 mSv, respectively. No specific complications occurred after CCTA and CTO procedures. Intraprocedural CCTA for identifying the location of the guidewires is feasible and safe when used for various CTO procedural steps.
Evaluation of individually body weight adapted contrast media injection in coronary CT-angiography
2016, European Journal of Radiology
Contrast media (CM) injection protocols should be customized to the individual patient. Aim of this study was to determine if software tailored CM injections result in diagnostic enhancement of the coronary arteries in computed tomography angiography (CTA) and if attenuation values were comparable between different weight categories.
265 consecutive patients referred for routine coronary CTA were scanned on a 2nd generation dual-source CT. Group 1 (n = 141) received an individual CM bolus based on weight categories (39–59 kg; 60–74 kg; 75–94 kg; 95–109 kg) and scan duration (‘high-pitch: 1 s; “dual-step prospective triggering”: 7 s), as determined by contrast injection software (Certegra™ P3T, Bayer, Berlin, Germany). Group 2 (n = 124) received a standard fixed CM bolus; Iopromide 300mgI/ml; volume: 75 ml; flow rate: 7.2 ml/s. Contrast enhancement was measured in all proximal and distal coronary segments. Subjective and objective image quality was evaluated. Statistical analysis was performed using SPSS (IBM, version 20.0).
For group 1, mean attenuation values of all segments were diagnostic (>325 HU) without statistical significant differences between different weight categories (p > 0.17), proximal vs. distal: 449 ± 65–373 ± 58 HU (39–59 kg); 443 ± 69–367 ± 81 HU (60–74 kg); 427 ± 59–370 ± 61 HU (75–94 kg); 427 ± 73–347 ± 61 HU (95–109 kg). Mean CM volumes were: 55 ± 6 ml (39–59 kg); 61 ± 7 ml (60–74 kg); 71 ± 8 ml (75–94 kg); 84 ± 9 ml (95–109 kg). For group 2, mean attenuation values were not all diagnostic with differences between weight categories (p < 0.01), proximal vs. distal: 611 ± 142–408 ± 69 HU (39–59 kg); 562 ± 135–389 ± 98 HU (60–74 kg); 481 ± 83–329 ± 81 HU (75–94 kg); 420 ± 73–305 ± 35 HU (95–109 kg). Comparable image noise and image quality were found between groups (p ≥ 0.330).
Individually tailored CM injection protocols yield diagnostic attenuation and a more homogeneous enhancement pattern between different weight groups. CM volumes could be reduced for the majority of patients utilizing individualized CM bolus application.
Contrast volume reduction adapted to body mass index for 320-slice coronary computed tomography angiography: Results from four-year clinical routine at a single center
2014, International Journal of Cardiology
An individualized contrast material injection protocol with respect to patient-related factors for dual-source CT coronary angiography
2014, Clinical Radiology
Citation Excerpt :
A previous study reported that coronary arterial enhancement increased with increasing body mass index (BMI) after the dose of CM was tailored to BW linearly.15 Further, only a few reports have been published on the use of BW-adapted injection protocols for CCTA.6,16 An additional important patient-related factor affecting the magnitude of CM enhancement is CO.12 It has been clinically observed that reduced CO results in delayed and increased arterial enhancement.13
To optimize contrast media (CM) injection protocols by individually tailoring the dose to the patient's body weight (BW), body mass index (BMI) and heart rate (HR) at dual-source computed tomography coronary angiography (DSCT-CA).
A total of 423 patients were prospectively enrolled and were randomly assigned to four groups. The control group received 80 ml CM at 5 ml/s. For the HR-optimized group, the injection duration was the same as the scan duration plus 8 s. In the Body-optimized group, the dose of CM was tailored to BW and BMI. In the HR + Body-optimized group, CM protocols tailored to body size and scan duration were applied. Individual variability of arterial attenuation and incidence of arterial over-opacification (attenuation >500 HU) in the four groups were compared. Correlations between BW, BMI, HR, and arterial attenuations were evaluated in the four groups, respectively.
Reduced individual variability of arterial attenuation and a significantly lower incidence of arterial over-opacification were found in the Body-optimized group and HR + Body-optimized group. Arterial attenuation was inversely correlated with BW, BMI, and HR in the control group, inversely correlated with BW and BMI in the HR-optimized group, and inversely correlated with HR in the Body-optimized group. In the HR + Body-optimized group, arterial attenuation was not significantly correlated with BW, BMI, or HR respectively.
CM protocols individually tailored to BW, BMI, and HR can lead to reduced individual variability and a lower incidence of over-opacification of arterial attenuation, but also can reduce the influence of BW, BMI, and HR on arterial attenuations at DSCT-CA.

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Original investigationFeasibility of Low-volume Injections of Contrast Material with a Body Weight–Adapted Iodine-Dose Protocol in 320-Detector Row Coronary CT Angiography

Rationale and Objectives

Materials and Methods

Results

Conclusion

Section snippets

Patients

Results

Discussion

Lancet

Eur J Radiol

Detection of coronary artery stenoses by contrast-enhanced, retrospectively electrocardiographically-gated, multislice spiral computed tomography

Circulation

Clinical use of multislice spiral computed tomography in 210 highly preselected patients: experience with 4 and 16 slice technology

Heart

Computed tomography coronary angiography with 370-millisecond gantry rotation time: evaluation of the best image reconstruction interval

J Comput Assist Tomogr

Higher intracoronary attenuation improves diagnostic accuracy in MDCT coronary angiography

AJR Am J Roentgenol

Intravenous contrast material administration at helical 16-detector row CT coronary angiography: effect of iodine concentration on vascular attenuation

Radiology

Coronary CT angiography

Radiology

Coronary angiography by 64-detector row computed tomography using low dose of contrast material with saline chaser: influence of total injection volume on vessel attenuation

J Comput Assist Tomogr

Contrast injection protocols for coronary computed tomography angiography using a 64-detector scanner: comparison between patient weight-adjusted- and fixed iodine-dose protocols

Invest Radiol

Initial evaluation of coronary images from 320-detector row computed tomography

Int J Cardiovasc Imaging

Original investigation
Feasibility of Low-volume Injections of Contrast Material with a Body Weight–Adapted Iodine-Dose Protocol in 320-Detector Row Coronary CT Angiography