Initial experience on the application of 320-row CT angiography with low-dose prospective ECG-triggered in children with congenital heart disease

Model-based iterative reconstruction for 320-detector row CT angiography reduces radiation exposure in infants with complex congenital heart disease

PURPOSE

We investigated the impact of model-based iterative reconstruction (MBIR) on 320-detector row computed tomography angiography (CTA) in infants with complex congenital heart disease (CHD).

METHODS

Seventy infants with complex CHD who underwent 320-detector row CTA (40 boys and 30 girls; age range, 0-22 months; median age, 60 days) were retrospectively evaluated. First, the images were reconstructed by filtered back projection (FBP), hybrid iterative reconstruction (HIR), or MBIR in 20 cases, and variables were compared among the three iterative reconstruction methods (IR test). Second, the variables were compared between 25 cases scanned using HIR and 25 cases scanned using MBIR, with a 20 standard deviation noise level for both. Attenuation values and contrast-to-noise ratios (CNRs) of the great vessels and heart chambers were calculated. Total dose-length products were recorded for all patients (radiation dose: RD test).

RESULTS

In the IR test, the mean CNR values were 4.8±1.3 for FBP, 6.9±1.4 for HIR, and 8.2±1.7 for MBIR (P < 0.0001). The best subjective image qualities in the great vessels and heart chambers were obtained with MBIR. In RD testing, no significant differences between HIR and MBIR in image quality (CNR: HIR, 8.4±2.4; MBIR, 8.3±2.4) were observed. The effective dose was significantly lower for MBIR than for HIR (0.7±0.2 vs. 1.1±0.3 mSv; P < 0.001).

CONCLUSION

The MBIR algorithm significantly improved image quality and decreased radiation exposure in 320-row CTA of infants with complex CHD, providing an alternative to FBP or HIR that is both safer and produces better results.

Comparison of echocardiography and 320-row multidetector computed tomography for the diagnosis of congenital heart disease in children

INTRODUCTION

Echocardiography (echo) is the primary non-invasive imaging modality for the assessment of congenital heart disease (CHD). Computed tomography angiography (CTA) also has potential to examine the anatomy of complex heart anomalies as well as extracardiac involvement.

OBJECTIVES

The aim of this study is to determine the impact of new CTA technology in the diagnosis of CHD and to compare echo and CTA in terms of diagnostic accuracy.

METHODS

Forty-five patients who underwent preoperative echo and CTA assessment in the intensive care unit were included in this study. The results were assessed for three main types of CHD (cardiac malformations, cardiac-major vessel connections and major vessels). The main groups were also divided into subgroups according to surgical features in order to assess them more objectively. Imaging methods were compared for diagnostic accuracy, sensitivity and specificity, while surgical findings were accepted as the gold standard.

RESULTS

Patients' median age and weight were two months (three days-eight years) and 12 kg (2.5-60 kg), respectively. In 45 operated cases, 205 subgroup malformations were assessed. Diagnostic accuracy was significantly greater in echo (echo vs. CTA: 98.4% and 96.2% [chi-square=6.4, p=0.011]). During surgery, 84 cardiac malformations (echo vs. CTA: 97.4% and 95.1% [chi-square=4.9, p=0.03]), 47 cardiac-major vessel connections (echo vs. CTA: 98.3% and 95.4% [chi-square=7.5, p=0.03]), and 74 major vessel malformations (echo vs. CTA: 96% and 98% [chi-square=1.8, p=0.48]) were confirmed.

CONCLUSION

Echocardiography and CTA are imaging methods with high diagnostic accuracy in children with CHD. The use of echocardiography together with CTA, especially for the visualization of extracardiac anatomy, provides additional information for clinicians.

Comparison of echocardiography and 320-row multidetector computed tomography for the diagnosis of congenital heart disease in children

INTRODUCTION

Echocardiography (echo) is the primary non-invasive imaging modality for the assessment of congenital heart disease (CHD). Computed tomography angiography (CTA) also has potential to examine the anatomy of complex heart anomalies as well as extracardiac involvement.

OBJECTIVES

The aim of this study is to determine the impact of new CTA technology in the diagnosis of CHD and to compare echo and CTA in terms of diagnostic accuracy.

METHODS

Forty-five patients who underwent preoperative echo and CTA assessment in the intensive care unit were included in this study. The results were assessed for three main types of CHD (cardiac malformations, cardiac-major vessel connections and major vessels). The main groups were also divided into subgroups according to surgical features in order to assess them more objectively. Imaging methods were compared for diagnostic accuracy, sensitivity and specificity, while surgical findings were accepted as the gold standard.

RESULTS

Patients' median age and weight were two months (three days-eight years) and 12 kg (2.5-60 kg), respectively. In 45 operated cases, 205 subgroup malformations were assessed. Diagnostic accuracy was significantly greater in echo (echo vs. CTA: 98.4% and 96.2% [chi-square=6.4, p=0.011]). During surgery, 84 cardiac malformations (echo vs. CTA: 97.4% and 95.1% [chi-square=4.9, p=0.03]), 47 cardiac-major vessel connections (echo vs. CTA: 98.3% and 95.4% [chi-square=7.5, p=0.03]), and 74 major vessel malformations (echo vs. CTA: 96% and 98% [chi-square=1.8, p=0.48]) were confirmed.

CONCLUSION

Echocardiography and CTA are imaging methods with high diagnostic accuracy in children with CHD. The use of echocardiography together with CTA, especially for the visualization of extracardiac anatomy, provides additional information for clinicians.

Effect of aortic arch surgery in newborns' cerebral and gastrointestinal hemodynamics: evaluation by Doppler ultrasonography

AIM

In this study, we investigated changes in newborns' cerebral and intestinal blood flow who had undergone aortic arch surgery.

METHOD

This study was carried out prospectively as a preliminary study in patients younger than 30 days at the time of aortic arch reconstruction between 1 August and 1 December, 2019. Cerebral and gastrointestinal hemodynamics were evaluated with Doppler USG before and 7 days after the operation. The middle cerebral artery (MCA) and celiac artery (CA) were used as measurement sites. Patients' peak systolic velocity (PSV), mean systolic velocity (MV), end diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) were evaluated.

RESULTS

A total of 16 patients enrolled in the study. The patients' median weight was 3.2 kg (2.7-4.5 kg), and age was 21 days (7-30 days). Six of them were female. Seven of the patients who underwent arcus reconstruction had an additional ventricular septal defect. The preoperative Doppler USG values of patients' were as follows: for MCA, the mean PSV was 37 ± 12 cm/s, EDV 12 ± 5 cm/s, MV 22 ± 19 cm/s, RI 0.70 ± 0.03, PI 1.24 ± 0.23, and for CA mean PSV was 67 ± 32 cm/s, EDV 29 ± 14 cm/s, MV 24 ± 9 cm/s, RI 0.79 ± 0.27, and PI 1.63 ± 0.89. Doppler USG values of patients' at the postoperative seventh day were as follows: for the MCA, mean PSV 41 ± 13 cm/s, EDV 13 ± 4 cm/s, MV 25 ± 10 cm/s, RI 0.64 ± 0.05, PI 1.23 ± 0.20, and for the CA mean PSV 70.5 ± 34 cm/s, EDV 32 ± 16 cm/s, MV 26 ± 8 cm/s, RI 0.75 ± 0.1, and PI 1.60 ± 0.38. There was a significant decrease in RI of both MCA and CA on the postoperative 7th day compared to the preoperative period (p < 0.05).

CONCLUSION

In newborns, there are significant changes in cerebral and intestinal blood flows after aortic arch surgery. RI decreased significantly, especially in the CA and MCA.

Low-dose Computed Tomography (CT) for the Diagnosis of Congenital Heart Disease in Children: A Meta-analysis

BACKGROUND

Low dose CT has become a promising examination method for the diagnosis of Congenital heart disease (CHD) in children because it has a low radiation dose, but it has not been widely accepted as an alternative to standard-dose CT in clinical applications due to concerns about image quality. Therefore, we suggest that the diagnostic accuracy, image quality, and radiation dose of low-dose CT for CHD in children should be fully explored through a metaanalysis of existing studies.

METHODS

A comprehensive search was performed to identify relevant English and Chinese articles (from inception to May 2019). All selected studies concerned the diagnosis of CHD in children using low-dose CT. The accuracy of low-dose CT was determined by calculating pooled estimates of sensitivity, specificity, diagnostic odds ratio, and likelihood ratio. Pooling was conducted using a bivariate generalized linear mixed model. Forest plots and summary receiver operating characteristic (SROC) curves were generated.

RESULTS

Ten studies, accounting for 577 patients, met the eligibility criteria. The pooled sensitivity and specificity were 0.95 (95% confidence interval (CI) 0.92-0.97) and 1.00 (95% CI 1.00- 1.00), respectively. The pooled diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio of low-dose CT were 12705.53 (95% CI 5065.00-31871.73), 671.29 (95% CI 264.77- 1701.97), and 0.05 (95% CI 0.03-0.08), respectively. Additionally, the area under the SROC curve was 1.00 (95% CI 0.99-1.00), suggesting that low-dose CT is an excellent diagnostic tool for CHD in children.

CONCLUSION

Low-dose CT, especially with a prospective ECG-triggering mode, provides excellent imaging quality and high diagnostic accuracy for CHD in children.

Comparison of image quality between synthetic and patients' electrocardiogram-gated 320-row pediatric cardiac computed tomography

BACKGROUND

Pediatric cardiac computed tomography (CT) can be acquired without electrode placement by using synthetic electrocardiogram (ECG).

OBJECTIVE

To determine whether the depiction of gross cardiac structures and coronary arteries in 320-row pediatric CT is not inferior when CT is gated with synthetic ECG at 150 beats per minute (bpm), compared to the patients' own ECG.

MATERIALS AND METHODS

Sixty 320-row CT examinations performed in children younger than 3 years old with congenital cardiac anomaly were enrolled in this retrospective study. Thirty examinations were scanned using the children's own ECG for gating and 30 examinations were scanned using synthetic ECG at 150 bpm. The image quality was compared between the two gating modes using a 3-point scale to delineate the following anatomical structures: atrial septum, ventricular septum, right atrium, right ventricle, left atrium, left ventricle, main pulmonary artery, ascending aorta, aortic arch including the patent ductus arteriosus, descending aorta, right coronary artery and left main trunk. Beam-hardening artifacts from contrast enhancement material were evaluated using a 3-point scale, and the overall image quality was evaluated using a 5-point scale.

RESULTS

Synthetic ECG was not inferior to the patients' ECG in depicting each structure, beam-hardening artifact and overall image quality. Average indices were clinically acceptable imaging quality, except for subjective image quality of mid and distal coronary arteries.

CONCLUSION

Pediatric cardiac CT in patients younger than 3 years old can be acquired using synthetic ECG gating, with image quality not inferior to the patients' ECG.

Combined prospectively electrocardiography- and respiratory-triggered sequential cardiac computed tomography in free-breathing children: success rate and image quality

BACKGROUND

Combined prospectively electrocardiography (ECG)- and respiratory-triggered sequential cardiac computed tomography (CT) has not been evaluated in free-breathing children.

OBJECTIVE

To evaluate the success rate and image quality of combined prospectively ECG- and respiratory-triggered sequential cardiac CT in free-breathing children.

MATERIALS AND METHODS

Image quality of combined prospectively ECG- and respiratory-triggered sequential cardiac CT in 870 children (≤5 years of age) was evaluated in terms of severe motion (maximal distance ≥2 mm) and band artifacts (maximal attenuation difference ≥100 Hounsfield units). The success rate of the scan mode was calculated. The causes of failed cases were assessed. Patient-related, radiation and image quality parameters were compared between success and failure groups.

RESULTS

Severe motion artifacts were observed in 10.6% (92/870) of patients due to cardiac phase error in 17 (18.5%), patient motion in 12 (13.0%), and unknown causes in 63 (68.5%). Severe band artifacts were seen in 13.2% (115/870) of patients. Combined prospectively ECG- and respiratory-triggered sequential cardiac CT was successfully performed in 78.5% (683/870) of patients, while it failed in 21.5% (187/870). All the evaluated patient-related, radiation and image quality parameters were significantly different (P≤0.001) between success and failure groups except effective dose (P>0.05).

CONCLUSION

Additional prospective respiratory triggering can reduce motion artifacts in prospectively ECG-triggered sequential cardiac CT in free-breathing children.

Free-breathing 320-row computed tomographic angiography with low-tube voltage and hybrid iterative reconstruction in infants with complex congenital heart disease

We explored the clinical value of low-tube voltage prospective second-generation ECG-triggered 320-row CT angiography in infants with complex CHD (37 male, 23 female, aged 0-2 years). The diagnostic accuracy of 320-row CT in complex CHD was 99.4% for intracardiac cardiovascular malformations, 99.8% for extracardiac cardiovascular malformations, and 100% for other malformations. The average subjective overall image quality score for cardiac structures was 3.7 ± 0.5 points. Second-generation 320-row CT angiography with low-tube voltage and prospective ECG-triggered volume target scanning allows accurate diagnosis of cardiovascular anomalies in infants with complex CHD.

A pilot study of a cardiovascular virtual endoscopy system based on multi-detector computed tomography in diagnosing tetralogy of Fallot in pediatric patients

The present study aimed to investigate the capabilities of the cardiovascular virtual endoscopy (VE) system in diagnosing tetralogy of Fallot (TOF) and performing measurements. A total of 37 patients underwent two-dimensional echocardiography (2-DE) and multi-detector computed tomography (MDCT) examinations. The obtained MDCT images were applied to a cardiovascular VE system. Diagnostic time by VE was first studied and compared with MDCT. Subsequently, with surgical findings as the ground truth, the capabilities of VE, 2-DE and MDCT in diagnosing TOF and its complications were investigated. Additionally, measurements on aorta overriding ratio and diameters for the left pulmonary artery, right pulmonary artery and right ventricular outflow tract by 2-DE and VE were analyzed. Diagnostic time by VE was significantly shorter than MDCT (188±42 vs. 303±42 sec, respectively; P<0.0001). VE, MDCT and 2-DE demonstrated comparable diagnostic rates of TOF (35/37 vs. 34/37 vs. 32/37, respectively; P>0.05). Similar findings were demonstrated in diagnosing complications of the muscular ventricular septal defects, patent ductus arteriosus, vagus subclavian artery, right arch, double superior vena cava and pulmonary artery. Furthermore, in diagnosing the atrial septal defect, 2-DE outperformed MDCT and VE (accuracy, 100 vs. 81 vs. 73%, respectively; all P<0.05). In performing relevant measurements, VE outperformed MDCT and 2-DE, particularly in accessing aorta overriding ratios with no intra-operator difference (P=0.3770) and high consistency (r=0.916). In conclusion, cardiovascular VE was demonstrated to have acceptable accuracy in diagnosing TOF, and possess advantages in shortening the diagnostic time and in performing measurements.

Comparison of Echocardiography and 64-Multislice Spiral Computed Tomography for the Diagnosis of Pediatric Congenital Heart Disease

BACKGROUND The goals of this study were: to compare echocardiogram and 64-multislice spiral computed tomography (64-MSCT) in diagnosing pediatric congenital heart disease; to determine the significance of ECHO for diagnosing congenital heart disease; and to identify the appropriate diagnosis for congenital heart disease through combined use of 64-MSCT and ECHO. MATERIAL AND METHODS Thirty patients underwent both ECHO and 64-MSCT diagnoses before their surgeries. Imaging from ECHO and 64-MSCT were analyzed by 4 specialists. The diagnostic accuracy and kappa value of ECHO and 64-MSCT were evaluated based on the operation results. The accuracy of the 2 methods was evaluated using the McNemar χ² test. RESULTS We confirmed 138 malformations in 30 children by surgery. The diagnostic accuracy of ECHO and 64-MSCT was 98.40% and 96.20%, respectively, with a significant difference between the 2 results (χ²=6.404, P=0.011). We compared prognosis accuracy and uniformity on 3 types of congenital heart disease (cardiac malformation, heart-large vascular connecting malformation, and large vascular malformation): 56 cardiac malformations were confirmed by surgery, in which the diagnostic accuracy of ECHO and 64-MSCT was 99.50% and 94.80%, respectively. (χ²=8.578, P=0.034); 31 heart-large vascular connecting malformations were confirmed by surgery, in which the diagnostic accuracy of ECHO and 64-MSCT was 99.00% and 95.42% (χ²=6.779, P=0.009); and 51 vascular malformations were confirmed, in which the diagnostic accuracy of ECHO and 64-MSCT was 96.30% and 98.30% (χ²=1.806, P=0.179). CONCLUSIONS ECHO is more effective than 64-MSCT in preoperative diagnosis of congenital heart disease, especially for children.

Image Quality of Coronary Computed Tomography Angiography with 320-Row Area Detector Computed Tomography in Children with Congenital Heart Disease

The objective of this study was to assess factors affecting image quality of 320-row computed tomography angiography (CTA) of coronary arteries in children with congenital heart disease (CHD). We retrospectively reviewed 28 children up to 3 years of age with CHD who underwent prospective electrocardiography (ECG)-gated 320-row CTA with iterative reconstruction. We assessed image quality of proximal coronary artery segments using a five-point scale. Age, body weight, average heart rate, and heart rate variability were recorded and compared between two groups: patients with good diagnostic image quality in all four coronary artery segments and patients with at least one coronary artery segment with nondiagnostic image quality. Altogether, 96 of 112 segments (85.7 %) had diagnostic-quality images. Patients with nondiagnostic segments were significantly younger (10.0 ± 11.6 months) and had lower body weight (5.9 ± 2.9 kg) (each p < 0.05) than patients with diagnostic image quality of all four segments (20.6 ± 13.8 months and 8.4 ± 2.5 kg, respectively; each p < 0.05). Differences in heart rate and heart rate variability between the two imaging groups were not significant. Receiver operating characteristic analyses for predicting patients with nondiagnostic image quality revealed an optimal body weight cutoff of ≤5.6 kg and an optimal age cutoff of ≤12.5 months. Prospective ECG-gated 320-row CTA with iterative reconstruction provided feasible image quality of coronary arteries in children with CHD. Younger age and lower body weight were factors that led to poorer image quality of coronary arteries.

Comparison of radiation dose estimates, image noise, and scan duration in pediatric body imaging for volumetric and helical modes on 320-detector CT and helical mode on 64-detector CT

BACKGROUND

Advanced multidetector CT systems facilitate volumetric image acquisition, which offers theoretic dose savings over helical acquisition with shorter scan times.

OBJECTIVE

Compare effective dose (ED), scan duration and image noise using 320- and 64-detector CT scanners in various acquisition modes for clinical chest, abdomen and pelvis protocols.

MATERIALS AND METHODS

ED and scan durations were determined for 64-detector helical, 160-detector helical and volume modes under chest, abdomen and pelvis protocols on 320-detector CT with adaptive collimation and 64-detector helical mode on 64-detector CT without adaptive collimation in a phantom representing a 5-year-old child. Noise was measured as standard deviation of Hounsfield units.

RESULTS

Compared to 64-detector helical CT, all acquisition modes on 320-detector CT resulted in lower ED and scan durations. Dose savings were greater for chest (27-46%) than abdomen/pelvis (18-28%) and chest/abdomen/pelvis imaging (8-14%). Noise was similar across scanning modes, although some protocols on 320-detector CT produced slightly higher noise.

CONCLUSION

Dose savings can be achieved for chest, abdomen/pelvis and chest/abdomen/pelvis examinations on 320-detector CT compared to helical acquisition on 64-detector CT, with shorter scan durations. Although noise differences between some modes reached statistical significance, this is of doubtful diagnostic significance and will be studied further in a clinical setting.