Contrast medium injection protocols for coronary CT angiography: should contrast medium volumes be tailored to body weight or body surface area?

Wang, Yin; Yu, Yitong; Zhang, Y.; An, Yun Qiang; Hou, Zhiyong; Gao, Ying; Wang, H.-P.; Lü, Bin; Santis, Domenico De; Rollins, Jonathan D.; Schoepf, U. Joseph

doi:10.1016/j.crad.2019.12.005

Cited by 4 publications

(2 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Metoprolol was used to control the heart rate and heartbeat rhythm in patients with AF. The nonionic contrast agent iohexol (350 mgI/mL, 0.8 mL/kg) was injected venously using a double-barrel high-pressure syringe with a scan range from 0.5 cm below the tracheal bifurcation to the palpebral surface of the heart, which used the bolus tracking technique ( 11 , 12 ). Using the retrospective ECG gating technology, the scanning parameters were as follows: tube voltage 80–120 kV, tube current 280–350 mAs/rev, collimation 128×0.625, pitch 0.18, matrix 512×512, rotation time 330 ms, and scanning field of view (FOV) 250 mm, with adjustment of the scan voltage and current according to the patient’s body mass index (BMI) to reduce scanning dose.…”

Section: Methodsmentioning

confidence: 99%

Morphological changes in the orifices of the left atrial appendage and left atrium in patients with atrial fibrillation

Tian¹,

Wang²,

Gao³

et al. 2022

Quant Imaging Med Surg

View full text Add to dashboard Cite

Background: As an integral part of the left atrium (LA), the left atrial appendage (LAA) plays an important role in atrial fibrillation (AF). However, the relationship between LAA remodeling and AF has not been clearly defined. This retrospective case-control study aimed to assess the morphological and functional features of the LA and the LAA in AF patients using images obtained by computed tomography angiography (CTA).Methods: A total of 140 AF patients and 64 patients without AF or other cardiovascular diseases who underwent CTA scans between September 2016 and August 2017 were enrolled in this observational study as the experimental and the control groups, respectively. The major and minor axes, area, and perimeter of the LAA orifice, the LAA depth, and the volume of both the LAA and LA were analyzed. The data of the AF group and the control group were compared. The t-test was used to analyze the normally distributed data, and the Wilcoxon rank-sum test was used for abnormally distributed data. The best critical value of predictors of AF was calculated using receiver operating characteristic (ROC) curve analysis. The correlation of the LAA volume change with the major and minor axes, area, and perimeter of the LAA orifice, and the LAA depth were analyzed using the Pearson correlation coefficient. Results:The LAA orifice's minor axis, LAA volume, and LA volume were significantly greater (P=0.004, P=0.010, and P<0.001, respectively) in patients with AF than in those without AF. The LAA volume [95% confidence interval (CI): 1.01 to 1.30; P=0.038] and LA volume (95% CI: 1.03 to 1.07; P<0.001) were significantly independent predictors of AF. An LAA volume of 8.75 mL had the highest predictive value for AF [area under the curve (AUC), 0.612], with a sensitivity of 76.6% and a specificity of 48.6%. In contrast, an LA volume of 97.15 mL had the highest predictive value for AF (AUC, 0.771), with a sensitivity of 90.6% and a specificity of 53.6%. The change of LAA volume was positively weakly correlated with the area and perimeter of the LAA orifice (r=0.1703 and r=0.1378, respectively). The LAA emptying fraction was negatively correlated with the major axis and the area of the LAA orifice. The major and minor axes, area, and perimeter of the LAA orifice, and LAA depth were significantly greater in female than in male patients (P=0.003, P=0.003, P=0.001, P=0.019, and P<0.001, respectively). Conclusions:The AF patients had a longer minor axis of the LAA orifice than that of the control group, resulting in a more circular LAA orifice. The LAA orifice area and perimeter were positively correlated with LAA volume change. The LAA orifice major and minor axes, area, and perimeter, and the LAA depth of the female patients were significantly greater than those of their male counterparts in AF patients.

show abstract

Section: Methodsmentioning

confidence: 99%

Morphological changes in the orifices of the left atrial appendage and left atrium in patients with atrial fibrillation

Tian¹,

Wang²,

Gao³

et al. 2022

Quant Imaging Med Surg

View full text Add to dashboard Cite

show abstract

“…Martin et al [ 23 ] evaluated the feasibility of a vendor’s software using a tube voltage-tailored CM application, which still resulted in more than 25% of the CTAs with attenuations in the ascending aorta below 400 HU. In another study with bolus tracking, Yin et al [ 24 ] evaluated protocols tailored for BMI or BSA, and, either way, cases of insufficient attenuation in the aorta occurred. The use of AI, as presented in the current study, could potentially improve different protocols by automatically detecting cases with insufficient attenuation when using a test bolus protocol.…”

Section: Discussionmentioning

confidence: 99%

Machine learning-based prediction of insufficient contrast enhancement in coronary computed tomography angiography

et al. 2022

View full text Add to dashboard Cite

Objectives Patient-tailored contrast delivery protocols strongly reduce the total iodine load and in general improve image quality in CT coronary angiography (CTCA). We aim to use machine learning to predict cases with insufficient contrast enhancement and to identify parameters with the highest predictive value. Methods Machine learning models were developed using data from 1,447 CTs. We included patient features, imaging settings, and test bolus features. The models were trained to predict CTCA images with a mean attenuation value in the ascending aorta below 400 HU. The accuracy was assessed by the area under the receiver operating characteristic (AUROC) and precision-recall curves (AUPRC). Shapley Additive exPlanations was used to assess the impact of features on the prediction of insufficient contrast enhancement. Results A total of 399 out of 1,447 scans revealed attenuation values in the ascending aorta below 400 HU. The best model trained using only patient features and CT settings achieved an AUROC of 0.78 (95% CI: 0.73–0.83) and AUPRC of 0.65 (95% CI: 0.58–0.71). With the inclusion of the test bolus features, it achieved an AUROC of 0.84 (95% CI: 0.81–0.87), an AUPRC of 0.71 (95% CI: 0.66–0.76), and a sensitivity of 0.66 and specificity of 0.88. The test bolus’ peak height was the feature that impacted low attenuation prediction most. Conclusion Prediction of insufficient contrast enhancement in CT coronary angiography scans can be achieved using machine learning models. Our experiments suggest that test bolus features are strongly predictive of low attenuation values and can be used to further improve patient-specific contrast delivery protocols. Key Points • Prediction of insufficient contrast enhancement in CT coronary angiography scans can be achieved using machine learning models. • The peak height of the test bolus curve is the most impacting feature for the best performing model.

show abstract

Contrast media timing optimization for coronary CT angiography: a retrospective validation study in swine

et al. 2022

View full text Add to dashboard Cite

Objectives The objective was to retrospectively develop a protocol in swine for optimal contrast media timing in coronary CT angiography (CCTA). Methods Several dynamic acquisitions were performed in 28 swine (55 ± 24 kg) with cardiac outputs between 1.5 and 5.5 L/min, for 80 total acquisitions. The contrast was injected (1mL/kg, 5mL/s, Isovue 370), followed by dynamic scanning of the entire aortic enhancement curve, from which the true peak time and aortic and coronary enhancements were recorded as the reference standard. Each dataset was then used to simulate two different CCTA protocols—a new optimal protocol and a standard clinical protocol. For the optimal protocol, the CCTA was acquired after bolus tracking-based trigging using a variable time delay of one-half the contrast injection time interval plus 1.5 s. For the standard protocol, the CCTA was acquired after bolus tracking-based triggering using a fixed time delay of 5 s. For both protocols, the CCTA time, aortic enhancement, coronary enhancement, and coronary contrast-to-noise ratio (CNR) were quantitatively compared to the reference standard measurements. Results For the optimal protocol, the angiogram was acquired within −0.15 ± 0.75 s of the true peak time, for a mean coronary CNR within 7% of the peak coronary CNR. Conversely, for the standard CCTA protocol, the angiogram was acquired within −1.82 ± 1.71 s of the true peak time, for a mean coronary CNR that was 23% lower than the peak coronary CNR. Conclusions The optimal CCTA protocol improves contrast media timing and coronary CNR by acquiring the angiogram at the true aortic root peak time. Key Points • This study in swine retrospectively developed the mathematical basis of an improved approach for optimal contrast media timing in CCTA. • By combining dynamic bolus tracking with a simple contrast injection timing relation, CCTA can be acquired at the peak of the aortic root enhancement. • CCTA acquisition at the peak of the aortic root enhancement should maximize the coronary enhancement and CNR, potentially improving the accuracy of CT-based assessment of coronary artery disease.

show abstract

Contrast medium injection protocols for coronary CT angiography: should contrast medium volumes be tailored to body weight or body surface area?

Cited by 4 publications

References 20 publications

Morphological changes in the orifices of the left atrial appendage and left atrium in patients with atrial fibrillation

Morphological changes in the orifices of the left atrial appendage and left atrium in patients with atrial fibrillation

Machine learning-based prediction of insufficient contrast enhancement in coronary computed tomography angiography

Contrast media timing optimization for coronary CT angiography: a retrospective validation study in swine

Contact Info

Product

Resources

About