Accuracy, image quality and radiation dose comparison of high-pitch spiral and sequential acquisition on 128-slice dual-source CT angiography in children with congenital heart disease

Efficacy and safety of coronary computed tomography angiography in diagnosing coronary lesions in children

INTRODUCTION

Identification of paediatric coronary artery abnormalities is challenging. We studied whether coronary artery CT angiography can be performed safely and reliably in children.

MATERIALS

Retrospective analysis of consecutive coronary CT angiography scans was performed for image quality and estimated radiation dose. Both factors were assessed for correlation with electrocardiographic-gating technique that was protocoled on a case-by-case basis, radiation exposure parameters, image noise artefact parameters, heart rate, and heart rate variability.

RESULTS

Sixty scans were evaluated, of which 96.5% were diagnostic for main left and right coronaries and 91.3% were considered diagnostic for complete coronary arteries. Subjective image quality correlated significantly with lower heart rate, increasing patient age, and higher signal-to-noise ratio. Estimated radiation dose only correlated significantly with choice of electrocardiographic-gating technique with median doses as follows: 2.42 mSv for electrocardiographic-gating triggered high-pitch spiral technique, 5.37 mSv for prospectively triggered axial sequential technique, 3.92 mSv for retrospectively gated technique, and 5.64 mSv for studies which required multiple runs. Two scans were excluded for injection failure and one for protocol outside the study scope. Five non-diagnostic cases were attributed to breathing motion, scanning prior to peak contrast enhancement, or scan acquisition during the incorrect portion of the R-R interval.

CONCLUSIONS

Diagnostic-quality coronary CT angiography can be performed reliably with a low estimated radiation exposure by tailoring each scan protocol to the patient's body habitus and heart rate. We propose coronary CT angiography is a safe and effective diagnostic modality for coronary artery abnormalities in children.

Diagnostic Validity and Reliability of Low-Dose Prospective ECG-Triggering Cardiac CT in Preoperative Assessment of Complex Congenital Heart Diseases (CHDs)

For the precise preoperative evaluation of complex congenital heart diseases (CHDs) with reduced radiation dose exposure, we assessed the diagnostic validity and reliability of low-dose prospective ECG-gated cardiac CT (CCT). Forty-two individuals with complex CHDs who underwent preoperative CCT as part of a prospective study were included. Each CCT image was examined independently by two radiologists. The primary reference for assessing the diagnostic validity of the CCT was the post-operative data. Infants and neonates were the most common age group suffering from complex CHDs. The mean volume of the CT dose index was 1.44 ± 0.47 mGy, the mean value of the dose-length product was 14.13 ± 5.4 mGy*cm, and the mean value of the effective radiation dose was 0.58 ± 0.13 mSv. The sensitivity, specificity, PPV, NPV, and accuracy of the low-dose prospective ECG-gated CCT for identifying complex CHDs were 95.6%, 98%, 97%, 97%, and 97% for reader 1 and 92.6%, 97%, 95.5%, 95.1%, and 95.2% for reader 2, respectively. The overall inter-reader agreement for interpreting the cardiac CCTs was good (κ = 0.74). According to the results of our investigation, low-dose prospective ECG-gated CCT is a useful and trustworthy method for assessing coronary arteries and making a precise preoperative diagnosis of complex CHDs.

CT coronary angiogram in children with Kawasaki patients: experience in 52 patients

BACKGROUND

CT is an accepted non-invasive imaging tool to assess the coronary arteries in adults; however, its utilisation in children is limited by high heart rate and lack of standardised protocol. We sought to assess diagnostic quality and factors that affect image quality of CT in assessing coronary artery lesions in Kawasaki patients less than 18 years of age.

METHODOLOGY

CT coronary angiography was performed on patients with Kawasaki disease diagnosed with coronary aneurysm or suspected to have coronary stenosis. Studies were performed using electrocardiogram-gated protocols. General anaesthesia was used in patients who were not cooperative for breathing control. Heart rate, image quality, and effective radiation dose were documented.

RESULTS

Fifty-two Kawasaki patients underwent CT coronary angiography to assess coronary artery lesions. Median heart rate was 88 beats per minute (range 50-165 beats/minute). Image quality was graded as excellent in 34 (65%) patients, good in 17 (32%), satisfactory in 1, and poor in 1 patient. Coronary artery aneurysm was found in 25 (bilateral = 6, unilateral = 19, multiple = 11). Thrombus was found in 11 patients resulting in partial and total occlusion in 8 and 3 patients, respectively. Coronary stenosis was noted in 2 patients. The effective radiation dose was 1.296 millisievert (median 0.81 millisievert). Better diagnostic imaging quality was significantly related to lower heart rate (p = 0.007).

CONCLUSION

Electrocardiogram-triggered CT coronary angiography provides a good diagnostic assessment of coronary artery lesions in children with Kawasaki disease.

Accuracy and image quality of wide-detector revolution CT angiography combined with prospective ECG-triggered CT angiography in the diagnosis of congenital aortic arch anomalies in Chinese children

OBJECTIVE

To explore the accuracy and image quality of wide-detector revolution CT angiography combined with prospective ECG-triggered CT angiography in the diagnosis of congenital aortic arch anomalies in Chinese children.

METHODS

From January 2020 to July 2022, the clinical data of 57 children with congenital aortic arch anomalies confirmed by surgery were collected. All patients underwent CT angiography (CTA) with Revolution CT and transthoracic echocardiography (TTE) before the operation. The accuracy of CTA and TTE in the diagnosis of aortic arch anomalies was compared with the surgical results.

RESULT

The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CTA and TTE for congenital aortic arch anomalies (including intracardiac and extracardiac structural abnormalities) were 92.2% and 85.5%, 99.4%, and 99.1%, 97.4% and 95.6%, 98.1% and 96.9%, and 97.2% and 95.2%, respectively. Regarding extracardiac structural malformations, the sensitivity of CTA was 100%, whereas that of TTE was 78.6% (P < 0.001). Regarding intracardiac structural malformations, the sensitivity of CTA was 84.5%, whereas that of TTE was 92.5% (P < 0.001). Regarding satisfaction with the images in aortic arch anomalies, surgeons noted that the CTA images were more useful for diagnosis and operation planning compared with TTE.

CONCLUSION

Wide-detector revolution CT angiography combined with prospective ECG triggering can be routinely used to assess congenital aortic arch anomalies, providing adequate image quality and high diagnostic accuracy. However, limitations in the identification of intracardiac structural abnormalities are noted.

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.

Prognostic Value of CTA-Derived Left Ventricular Mass in Neonates with Congenital Heart Disease

For therapeutic decisions regarding uni- or biventricular surgical repair in congenital heart disease (CHD), left ventricular mass (LVM) is an important factor. The aim of this retrospective study was to determine the LVM of infants with CHD in thoracic computed tomography angiographies (CTAs) and to evaluate its usefulness as a prognostic parameter, with special attention paid to hypoplastic left heart (HLH) patients. Manual segmentation of the left ventricular endo- and epicardial volumes was performed in CTAs of 132 infants. LVMs were determined from these volumes and normalized to body surface area. LVMs of patients with different types of CHD were compared to each other using analyses of variances (ANOVA). An LVM cutoff for discrimination between uni- and biventricular repair was determined using receiver operating characteristics. Survival rates were calculated using Kaplan–Meier statistics. Patients with a clinical diagnosis of an HLH had significantly lower mean LVM (21.88 g/m²) compared to patients without applicable disease (50.22 g/m²; p < 0.0001) and compared to other CHDs, including persistent truncus arteriosus, left ventricular outflow tract obstruction, transposition of the great arteries, pulmonary artery stenosis or atresia, and double-outlet right ventricle (all, p < 0.05). The LVM cutoff for uni- vs. biventricular surgery was 33.9 g/m² (sensitivity: 82.3%; specificity: 73.7%; PPV: 94.9%). In a subanalysis of HLH patients, a sensitivity of 50.0%, specificity of 100%, PPV of 100%, and NPV of 83.3% was determined. Patient survival was not significantly different between the surgical approaches or between patients with LVM above or below the cutoff. LVM can be measured in chest CTA of newborns with CHD and can be used as a prognostic factor.

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.

Effects of the Sn100 kVp Tube Voltage Mode on the Radiation Dose and Image Quality of Dual-Source Computed Tomography Pulmonary Angiography

OBJECTIVE

This study aimed to investigate the effects of the Sn100 kVp tube voltage mode on the image quality and radiation dose of computed tomography pulmonary angiography (CTPA).

METHODS

A total of 145 patients who underwent CTPA were randomly divided into five groups: control group (120 kVp, 150 mAs), test group A (Sn100 kVp, 270 mAs), test group B (120 kVp, 30 mAs), test group C (70 kVp, 150 mAs), and test group D (80 kVp, 70 mAs). After image post-processing, the image quality and radiation dose of each group were analyzed.

RESULTS

The computed tomography values of images in the four test groups were more than 250 HU, which met the criteria for diagnosis. The signal-to-noise ratio and contrast-to-noise ratio of the images in the four test groups were lower than those in the control group. The radiation dose in each test group was lower than in the control group. The radiation dose was lowest in test group A.

CONCLUSION

The Sn100 kVp energy spectrum purification protocol can meet the requirements for clinical diagnosis, ensure image quality, and reduce the dose of radiation that patients receive.

Feasibility of Low Volume of High-Concentration Iodinated Contrast Medium With 70 kVp Tube Voltage on High-Pitch Dual-Source Computed Tomography Angiography in Children With Congenital Heart Disease

OBJECTIVE

The objective of this study was to investigate the feasibility of high-concentration iodinated contrast medium (CM) with 70 kVp tube voltage on high-pitch dual-source computed tomography (DSCT) in children with congenital heart disease (CHD).

METHODS

Fifty-eight CHD patients underwent high-pitch DSCT in 2 protocols: 70 kVp tube voltage, 1.0 mL/kg CM volume, 370 mg I/mL concentration (group A); 80 kVp tube voltage, 1.5 mL/kg CM volume, 350 mg I/mL concentration (group B). The diagnostic accuracy, image quality, iodine delivery rate, iodine dose, and radiation dose were compared.

RESULTS

There was no significant difference in the diagnostic accuracy (P > 0.05), image quality (P > 0.05) and iodine delivery rate (P > 0.05) between the 2 groups. The iodine dose (P < 0.05) and radiation dose (P < 0.05) in group A were significantly lower than those in group B.

CONCLUSIONS

Reduction in iodine dose and radiation exposure can be achieved with 70 kVp high-pitch DSCT by administering a smaller volume of high-concentration CM in children with CHD.

Image quality and radiation dose of different scanning protocols in DSCT cardiothoracic angiography for children with tetralogy of fallot

The aim of this study was to investigate the image quality and radiation dose of different scanning protocols in dual-source CT cardiothoracic angiography for children with tetralogy of Fallot (TOF). Seventy-five consecutive children with known or suspected TOF were enrolled to undergo prospective ECG-triggering sequential dual-source CT (DSCT) cardiothoracic angiography. According to the scanning protocols, these patients were randomly divided into 3 groups: fixed delay time (FDT, n = 25, group A), automatic bolus-tracking (ABT, n = 25, group B) and manual bolus-tracking (MBT, n = 25, group C). Subjective and objective image quality were evaluated. The radiation doses were recorded. The image quality scores of group C were significantly higher than those of group A and B. The absolute value of difference (D-value) on CT attenuation between left (CT_LV) and right ventricle (CT_RV) in group C was significantly lower than that in group A and B. The total effective dose of groups A, B and C were 0.39 ± 0.06 mSv, 0.40 ± 0.07 mSv and 0.40 ± 0.08 mSv, respectively. There was no significant difference among 3 groups (P = 0.722). Scanning protocol has significantly impacts on the image quality of cardiovascular structures for TOF patients. Compared with the conventional scanning protocols FDT and ABT, the MBT technique provides high image quality and achieves more homogenous attenuation among different patients with TOF.

Dual-source computed tomography coronary artery imaging in children

Computed tomography (CT) has a well-established diagnostic role in the assessment of coronary arteries in adults. However, its application in a pediatric setting is still limited and often impaired by several technical issues, such as high heart rates, poor patient cooperation, and radiation dose exposure. Nonetheless, CT is becoming crucial in the noninvasive approach of children affected by coronary abnormalities and congenital heart disease. In some circumstances, CT might be preferred to other noninvasive techniques such as echocardiography and MRI for its lack of acoustic window influence, shorter acquisition time, and high spatial resolution. The introduction of dual-source CT has expanded the role of CT in the evaluation of pediatric cardiovascular anatomy and pathology. Furthermore, technical advances in the optimization of low-dose protocols represent an attractive innovation. Dual-source CT can play a key role in several clinical settings in children, namely in the evaluation of children with suspected congenital coronary artery anomalies, both isolated and in association with congenital heart disease. Moreover, it can be used to assess acquired coronary artery abnormalities, as in children with Kawasaki disease and after surgical manipulation, especially in case of transposition of the great arteries treated with arterial switch operation and in case of coronary re-implantation.

User-Friendly Vendor-Specific Guideline for Pediatric Cardiothoracic Computed Tomography Provided by the Asian Society of Cardiovascular Imaging Congenital Heart Disease Study Group: Part 1. Imaging Techniques

Optimal performance of pediatric cardiothoracic computed tomography (CT) is technically challenging and may need different approaches for different types of CT scanners. To meet the technical demands and improve clinical standards, a practical, user-friendly, and vendor-specific guideline for pediatric cardiothoracic CT needs to be developed for children with congenital heart disease (CHD). In this article, we have attempted to describe such guideline based on the consensus of experts in the Asian Society of Cardiovascular Imaging CHD Study Group. This first part describes the imaging techniques of pediatric cardiothoracic CT, and it includes recommendations for patient preparation, scan techniques, radiation dose, intravenous injection protocol, post-processing, and vendor-specific protocols.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Cardiovascular MRI and CT in congenital heart disease

Cardiovascular MRI and CT are useful imaging modalities complimentary to echocardiography. This review article describes the common indications and consideration for the use of MRI and CT in the management of congenital heart disease.

Image quality and radiation dose of ECG-triggered High-Pitch Dual-Source cardiac computed tomography angiography in children for the evaluation of central vascular stents

Assess image quality and radiation dose of ECG-triggered High-Pitch Dual-Source CTA for the evaluation central vascular stents in children. We included all children ≤ 21 years old with one or more central vascular stents and available prospective ECG-triggered High-Pitch Dual-Source CTA performed at our institution between January 2015 and August 2017. Demographic and scanner information was retrieved. Two board-certified pediatric radiologists blinded to the clinical data, independently reviewed and scored each case using a four-point quality score. Scores 1, 2 and 3 were considered of diagnostic image quality. Inter-observer agreement and non-parametric test were used. 18 patients (10 girls, 8 boys) with a mean age of 9.47 ± 7.38 years (mean ± SD) met inclusion criteria. Thirty-two central vascular stents were evaluated. Mean quality score was 2.07 ± 0.94 with 12.5% (4/32) of the cases classified as unevaluable. Interobserver agreement was excellent (k = 0.86). There is no significant difference between quality score and stent location (p = 0.07). There is a significant difference with stent material as all non-diagnostic scores were only seen in covered stents made of platinum-iridium (p < 0.001). There was no association between image quality and age, height, weight, BSA, heart rate, radiation dose or stent lumen size (p > 0.05). ECG-triggered high-pitch spiral DS-CTA offers appropriate image quality for assessment of central vascular stents in children.

High-pitch, 120 kVp/30 mAs, low-dose dual-source chest CT with iterative reconstruction: Prospective evaluation of radiation dose reduction and image quality compared with those of standard-pitch low-dose chest CT in healthy adult volunteers

PURPOSE

Objective of this study was to evaluate the effectiveness of the iterative reconstruction of high-pitch dual-source chest CT (IR-HP-CT) scanned with low radiation exposure compared with low dose chest CT (LDCT).

MATERIALS AND METHODS

This study was approved by the institutional review board. Thirty healthy adult volunteers (mean age 44 years) were enrolled in this study. All volunteers underwent both IR-HP-CT and LDCT. IR-HP-CT was scanned with 120 kVp tube voltage, 30 mAs tube current and pitch 3.2 and reconstructed with sinogram affirmed iterative reconstruction. LDCT was scanned with 120 kVp tube voltage, 40 mAs tube current and pitch 0.8 and reconstructed with B50 filtered back projection. Image noise, and signal to noise ratio (SNR) of the infraspinatus muscle, subcutaneous fat and lung parenchyma were calculated. Cardiac motion artifact, overall image quality and artifacts was rated by two blinded readers using 4-point scale. The dose-length product (DLP) (mGy∙cm) were obtained from each CT dosimetry table. Scan length was calculated from the DLP results. The DLP parameter was a metric of radiation output, not of patient dose. Size-specific dose estimation (SSDE, mGy) was calculated using the sum of the anteroposterior and lateral dimensions and effective radiation dose (ED, mSv) were calculated using CT dosimetry index.

RESULTS

Approximately, mean 40% of SSDE (2.1 ± 0.2 mGy vs. 3.5 ± 0.3 mGy) and 34% of ED (1.0 ± 0.1 mSv vs. 1.5 ± 0.1 mSv) was reduced in IR-HP-CT compared to LDCT (P < 0.0001). Image noise was reduced in the IR-HP-CT (16.8 ± 2.8 vs. 19.8 ± 3.4, P = 0.0001). SNR of lung and aorta of IR-HP-CT showed better results compared with that of LDCT (22.2 ± 5.9 vs. 33.0 ± 7.8, 1.9 ± 0.4 vs 1.1 ± 0.3, P < 0.0001). The score of cardiac pulsation artifacts were significantly reduced on IR-HP-CT (3.8 ± 0.4, 95% confidence interval, 3.7‒4.0) compared with LDCT (1.6 ± 0.6, 95% confidence interval, 1.3‒1.8) (P < 0.0001). SNR of muscle and fat, beam hardening artifact and overall subjective image quality of the mediastinum, lung and chest wall were comparable on both scans (P ≥ 0.05).

CONCLUSION

IR-HP-CT with 120 kVp and 30 mAs tube setting in addition to an iterative reconstruction reduced cardiac motion artifact and radiation exposure while representing similar image quality compared with LDCT.

Image Quality and Radiation Dose of High-Pitch Dual-Source Spiral Cardiothoracic Computed Tomography in Young Children with Congenital Heart Disease: Comparison of Non-Electrocardiography Synchronization and Prospective Electrocardiography Triggering

Objective

To compare image quality and radiation dose of high-pitch dual-source spiral cardiothoracic computed tomography (CT) between non-electrocardiography (ECG)-synchronized and prospectively ECG-triggered data acquisitions in young children with congenital heart disease.

Materials and Methods

Eighty-six children (≤ 3 years) with congenital heart disease who underwent high-pitch dual-source spiral cardiothoracic CT were included in this retrospective study. They were divided into two groups (n = 43 for each; group 1 with non-ECG-synchronization and group 2 with prospective ECG triggering). Patient-related parameters, radiation dose, and image quality were compared between the two groups.

Results

There were no significant differences in patient-related parameters including age, cross-sectional area, body density, and water-equivalent area between the two groups (p > 0.05). Regarding radiation dose parameters, only volume CT dose index values were significantly different between group 1 (1.13 ± 0.09 mGy) and group 2 (1.07 ± 0.12 mGy, p < 0.02). Among image quality parameters, significantly higher image noise (3.8 ± 0.7 Hounsfield units [HU] vs. 3.3 ± 0.6 HU, p < 0.001), significantly lower signal-to-noise ratio (105.0 ± 28.9 vs. 134.1 ± 44.4, p = 0.001) and contrast-to-noise ratio (84.5 ± 27.2 vs. 110.1 ± 43.2, p = 0.002), and significantly less diaphragm motion artifacts (3.8 ± 0.5 vs. 3.7 ± 0.4, p < 0.04) were found in group 1 compared with group 2. Image quality grades of cardiac structures, coronary arteries, ascending aorta, pulmonary trunk, lung markings, and chest wall showed no significant difference between groups (p > 0.05).

Conclusion

In high-pitch dual-source spiral pediatric cardiothoracic CT, additional ECG triggering does not substantially reduce motion artifacts in young children with congenital heart disease.

Depiction of the native coronary arteries during ECG-triggered High-Pitch Dual-Source Coronary Computed Tomography Angiography in children: Determinants of image quality

OBJECTIVE

Assess the image quality of ECG-triggered High-Pitch Dual-Source CTA for the evaluation of native coronaries in children.

MATERIALS AND METHODS

Between August 2014 and September 2017, 45 children with morphologically normal cardiac chambers had cardiac prospective ECG-triggered High-Pitch Dual-Source CTA. Two pediatric radiologists blinded to clinical data, independently reviewed each case. The coronary arteries were evaluated using a four-point scale quality score according to the coronary segment. Attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured using values from the air, inter-ventricular septum and ascending aorta at the level of the sinuses of Valsalva.

RESULTS

225 coronary segments were assessed showed a mean score of 2.40 ± 0.73, 94.2% had diagnostic image quality. The best and worst average quality were seen in segment 5 and 2, respectively. Inter-observer agreement was moderate for all segments except for segment 1, which was excellent. Worse quality scores were significantly associated with younger patients and low body mass index as well as with higher heart rates in all segments. The mean observed heart rate and BSA in patients with diagnostic image quality were below 77 bpm and over 1.4 m² respectively. There is no significant association between attenuation, SNR and CNR with image quality.

CONCLUSIONS

Prospective ECG-triggered High-Pitch Dual-Source Computed Tomography Angiography achieves consistent and diagnostic image quality for coronary artery assessment at a low effective dose in pediatric patients.

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.

Clinical validation and assessment of aortic hemodynamics using computational fluid dynamics simulations from computed tomography angiography

Background

Hemodynamic information including peak systolic pressure (PSP) and peak systolic velocity (PSV) carry an important role in evaluation and diagnosis of congenital heart disease (CHD). Since MDCTA cannot evaluate hemodynamic information directly, the aim of this study is to provide a noninvasive method based on a computational fluid dynamics (CFD) model, derived from multi-detector computed tomography angiography (MDCTA) raw data, to analyze the aortic hemodynamics in infants with CHD, and validate these results against echocardiography and cardiac catheter measurements.

Methods

This study included 25 patients (17 males, and 8 females; a median age of 2 years, range: 4 months–4 years) with CHD. All patients underwent both transthoracic echocardiography (TTE) and MDCTA within 2 weeks prior to cardiac catheterization. CFD models were created from MDCTA raw data. Boundary conditions were confirmed by lumped parameter model and transthoracic echocardiography (TTE). Peak systolic velocity derived from CFD models (PSV_CFD) was compared to TTE measurements (PSV_TTE), while the peak systolic pressure derived from CFD (PSP_CFD) was compared to catheterization (PSP_CC). Regions with low and high peak systolic wall shear stress (PSWSS) were also evaluated.

Results

PSV_CFD and PSP_CFD showed good agreements between PSV_TTE (r = 0.968, p < 0.001; mean bias = − 7.68 cm/s) and PSP_CC (r = 0.918, p < 0.001; mean bias = 1.405 mmHg). Regions with low and high PSWSS) can also be visualized. Skewing of velocity or helical blood flow was also observed at aortic arch in patients.

Conclusions

Our result demonstrated that CFD scheme based on MDCTA raw data is an accurate and convenient method in obtaining the velocity and pressure from aorta and displaying the distribution of PSWSS and flow pattern of aorta. The preliminary results from our study demonstrate the capability in combining clinical imaging data and novel CFD tools in infants with CHD and provide a noninvasive approach for diagnose of CHD such as coarctation of aorta in future.

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.

Assessment of transposition of the great arteries associated with multiple malformations using dual-source computed tomography

Purpose

To determine the value of dual-source computed tomography (DSCT) in depicting the morphological characteristics and diagnosing the associated malformations for patients with transposition of the great arteries (TGA) before surgery.

Materials and methods

Twenty-five patients with TGA who underwent DSCT and transthoracic echocardiography (TTE) examination were retrospectively reviewed. The morphological types of TGA, the spatial relationship between the pulmonary artery and the aorta, as well as coronary artery-associated abnormalities were assessed by DSCT. In contrast to TTE, the diagnostic accuracy of associated malformations on DSCT were analyzed and calculated with reference to surgical or digital subtraction angiography (DSA) findings. Effective doses (EDs) were also calculated.

Results

Among the 25 patients, 12 (48%) had ventricular septal defects and left ventricular outflow tract stenosis. Sixteen patients (16/25, 64%) had great arteries with an oblique spatial relationship on DSCT. In addition, we found seven patients (7/25, 28%) with coronary artery malformation, including five with an abnormal coronary origin and two with signs of a myocardial bridge. According to DSA or surgical findings, DSCT was superior to TTE in demonstrating extracardiac anomalies (sensitivity, anomalies of great vessels: 100% vs. 93.33%, other anomalies: 100% vs. 46.15%). The mean estimated ED for those aged <10 years was <2 mSv (1.59 ± 0.95 mSv).

Conclusions

DSCT can achieve an overall assessment of patients with TGA, including any associated malformations as well as the identification of the spatial relationship of the great arteries. DSCT can therefore be considered as an alternative imaging modality for surgical decision making.

Relationship between heart rate and quiescent interval of the cardiac cycle in children using MRI

BACKGROUND

Imaging the heart in children comes with the challenge of constant cardiac motion. A prospective electrocardiography-triggered CT scan allows for scanning during a predetermined phase of the cardiac cycle with least motion. This technique requires knowing the optimal quiescent intervals of cardiac cycles in a pediatric population.

OBJECTIVE

To evaluate high-temporal-resolution cine MRI of the heart in children to determine the relationship of heart rate to the optimal quiescent interval within the cardiac cycle.

MATERIALS AND METHODS

We included a total of 225 consecutive patients ages 0-18 years who had high-temporal-resolution cine steady-state free-precession sequence performed as part of a magnetic resonance imaging (MRI) or magnetic resonance angiography study of the heart. We determined the location and duration of the quiescent interval in systole and diastole for heart rates ranging 40-178 beats per minute (bpm). We performed the Wilcoxon signed rank test to compare the duration of quiescent interval in systole and diastole for each heart rate group.

RESULTS

The duration of the quiescent interval at heart rates <80 bpm and >90 bpm was significantly longer in diastole and systole, respectively (P<.0001 for all ranges, except for 90-99 bpm [P=.02]). For heart rates 80-89 bpm, diastolic interval was longer than systolic interval, but the difference was not statistically significant (P=.06). We created a chart depicting optimal quiescent intervals across a range of heart rates that could be applied for prospective electrocardiography-triggered CT imaging of the heart.

CONCLUSION

The optimal quiescent interval at heart rates <80 bpm is in diastole and at heart rates ≥90 bpm is in systole. The period of quiescence at heart rates 80-89 bpm is uniformly short in systole and diastole.

Image Quality of Coronary Arteries on Non-electrocardiography-gated High-Pitch Dual-Source Computed Tomography in Children with Congenital Heart Disease

This study aimed to evaluate image quality of coronary artery imaging on non-electrocardiography (ECG)-gated high-pitch dual-source computed tomography (DSCT) in children with congenital heart disease (CHD) and to assess factors affecting image quality. We retrospectively reviewed the records of 142 children with CHD who underwent non-ECG-gated high-pitch DSCT. The subjective image quality of the proximal coronary segments was graded using a five-point scale. A score <3 represented a non-diagnostic image. Age, body weight, and heart rate were compared between the two groups: patients with good diagnostic image quality in all four segments and patients with at least one segment with non-diagnostic image quality. Predictors of image quality were assessed by multivariate logistic regression, including age, body weight, and heart rate. Four-hundred-fifty-seven of the 568 segments (80.5%) had diagnostic image quality. Patients with non-diagnostic segments were significantly younger (21.6 ± 25.5 months), had lower body weight (7.82 ± 5.00 kg), and a faster heart rate (123 ± 23.7 beats/min) (each p < 0.05) than patients with diagnostic image quality in all four segments (30.6 ± 20.7 months, 10.3 ± 4.00 kg, and 113 ± 21.6 beats/min, respectively; each p < 0.05). The multivariate logistic regression revealed that body weight (odds ratio 1.228; p = 0.029) was a significant predictor of image quality. Non-ECG-gated high-pitch DSCT provided adequate image quality of the proximal coronary segments in children with CHD. Lower body weight was a factor that led to poorer image quality of the coronary arteries.

Application of low-dose dual-source computed tomography angiography in children with complex congenital heart disease

The objective of the present study was to evaluate image quality and radiation dosage using a low-dose prospectively electrocardiogram (ECG)-gated computed tomography (CT) protocol for dual-source angiography in children with complex congenital heart disease. A total of 206 patients with complex congenital heart disease were equally assigned into two groups at random. The children in group A underwent low-dose retrospective ECG-gated CT scanning with an ECG-pulsing technique, and group B underwent prospective ECG-gated scanning with an ECG-pulsing technique. Radiation dose volume computed tomography dose index (CTDI vol), dose length product (DLP) and effective dose (ED) were recorded after scanning. Raw data were transferred to workstations for post-processing, diagnosis, grading, comparison with intra-operation findings or cardiac catheterisation, and the coincidence, false negative rate and misdiagnosis rates of groups A and B, respectively, were subsequently recorded. The results of the present study indicated that the height, age and weight of the children in the two groups exhibited no significant differences. The image quality of group A was graded as 3.94±0.08, whereas the grade for the image quality in group B was 4.05±0.08; no significant difference was detected. The coincidence rates of groups A and B were 89.37 and 88.48%, respectively; the false negative rates of groups A and B were 9.66 and 10.60%, respectively; the misdiagnosis rates of groups A and B were 0.97 and 0.92%. No significant differences between the two groups were detected. The CTDI value of group A was 3.24±1.62 mGy, the DLP value was 47.53±33.28 mGy·cm², the ED value was 0.93±0.42 mSv. By contrast, the CTDI value of group B was 2.27±0.94 mGy, the DLP value was (27.03±17.64) mGy·cm², and the ED value was 0.53±0.23 mSv. Significant differences were detected between the two groups (CTDI t=5.287, P<0.05; DLP t=5.523, P<0.05; ED t=8.497, P<0.05), and the radiation dose of group B was markedly decreased, compared with group A. In conclusion, the present study demonstrated that prospectively ECG-gated scanning of dual-source CT is an effective method of examination for dose reduction in children with congenital heart disease without impairment of image quality, which suggests that this protocol may be suitable for future application and dissemination.

Evaluation of High-Pitch Ungated Pediatric Cardiovascular Computed Tomography for the Assessment of Cardiac Structures in Neonates

PURPOSE

We evaluated a high-pitch, non-electrocardiogram-gated cardiac computed tomographic protocol, designed to image both cardiac and extracardiac structures, including coronary arteries, in a neonatal population (less than 1 year old) that was referred for congenital heart disease assessment and compared it with an optimized standard-pitch protocol in an equivalent cohort.

MATERIALS AND METHODS

Twenty-nine high-pitch scans were compared with 31 age-matched, sex-matched, and weight-matched standard-pitch, dosimetrically equivalent scans. The visualization and subjective quality of both cardiac and extracardiac structures were scored by consensus between 2 trained blinded observers. Image noise, signal-to-noise and contrast-to-noise ratios, and radiation doses were also compared.

RESULTS

The high-pitch protocol better demonstrated the pulmonary veins (P=0.03) and all coronary segments (all P<0.05), except the distal right coronary artery (P=0.10), with no significant difference in the visualization of the remaining cardiac or extracardiac structures. Both contrast-to-noise and signal-to-noise ratios improved due to greater vessel opacity, with significantly fewer streak (P<0.01) and motion (P<0.01) artifacts. Image noise and computed tomographic dose index were comparable across the 2 techniques; however, the high-pitch acquisition resulted in a small, but statistically significant, increase in dose-length product [13.0 mGy.cm (9.0 to 17.3) vs. 11.0 mGy.cm (9.0 to 13.0), P=0.05] due to greater z-overscanning.

CONCLUSIONS

In neonates, a high-pitch protocol improves coronary artery and pulmonary vein delineation compared with the standard-pitch protocol, allowing a more comprehensive assessment of cardiovascular anatomy while obviating the need for either patient sedation or heart rate control.

Radiation Dose and Image Quality in Pediatric Cardiac Computed Tomography: A Comparison Between Sequential and Third-Generation Dual-Source High-Pitch Spiral Techniques

The aim of this study was to investigate whether there is a reduction in radiation dose and improvement in image quality of pediatric cardiac computed tomography scans performed using the high-pitch spiral technique on a new third-generation dual-source 2 × 192-slice scanner (group B) compared with scans performed using the sequential technique on a single-source 256-slice scanner (group A). We performed a retrospective observational study on 40 patients aged ≤18 years who underwent prospectively electrocardiogram-triggered cardiac computed tomography. Image quality was assessed by pre-defined objective indices and a four-point subjective score. Apart from a higher mean heart rate in group A (P = 0.016), there were otherwise no significant inter-group differences in patient characteristics. The median effective dose was 4.41 mSv (interquartile range 2.58-5.90 mSv) in group A and 0.52 mSv (interquartile range 0.39-0.59 mSv) in group B (P < 0.001), representing a 88 % reduction. Subjective image quality score was significantly better in group B (4 = excellent with no artifact, mode 57.1 %) than in group A (3 = good with mild artifact, mode 57.9 %) (P < 0.001). Noise index, signal-to-noise ratio and contrast-to-noise ratio between both groups were not statistically significant. New third-generation dual-source high-pitch spiral scan technique can deliver excellent image quality with low radiation dose. Our results suggest that it should be considered as a first-choice technique for performing cardiac computed tomography in the pediatric population.

Comparison of 128-Slice Low-Dose Prospective ECG-Gated CT Scanning and Trans-Thoracic Echocardiography for the Diagnosis of Complex Congenital Heart Disease

Objective

To compare prospective ECG-gated multi-slice computed tomography (MSCT) and trans-thoracic echocardiography (TTE) in the diagnosis of complex congenital heart disease (CHD).

Methods

This was a prospective study of consecutive patients with complex CHD (age <7 years) treated at a tertiary hospital between May 2013 and May 2015. All patients were imaged with TTE and prospective ECG-gated 128-slice spiral CT in the week before surgery. Effective radiation dose (ED) was calculated from volume CT dose index (CTDIvol) and dose length product (DLP). Image quality (5-point scale) was assessed independently by two radiologists. Using surgical findings as the reference, the diagnostic capabilities of MSCT and TTE were compared.

Results

Thirty-five patients (19 males) aged 1.59±1.58 years (range, 3 days to 74 months) were included. CTDIvol, DLP and ED were 0.90±0.24 mGy, 12.9±4.7 mGy∙cm and 0.64±0.21 mSv (range, 0.358–1.196 mSv), respectively. Image quality score was 4.3±0.5, and all images met the diagnostic requirements. The sensitivity, specificity, positive predictive value, and negative predictive value for diagnosing CHD were 97.2%, 99.8%, 99.0%, and 99.5%, respectively, for MSCT, and 90.6%, 99.8%, 99.0%, and 98.4%, respectively, for TTE. MSCT not only had a higher sensitivity than TTE overall (97.2% vs. 90.6%; P<0.05), but was much more sensitive for the diagnosis of extracardiac vascular abnormalities (92.0% vs. 68.0%; P<0.05).

Conclusion

128-slice low-dose prospective ECG-gated CT scanning has important clinical value in the diagnosis of complex CHD in children, complementing and extending the findings of TTE.

Image quality of ct angiography using model-based iterative reconstruction in infants with congenital heart disease: Comparison with filtered back projection and hybrid iterative reconstruction

PURPOSE

To compare the image quality, rate of coronary artery visualization and diagnostic accuracy of 256-slice multi-detector computed tomography angiography (CTA) with prospective electrocardiographic (ECG) triggering at a tube voltage of 80kVp between 3 reconstruction algorithms (filtered back projection (FBP), hybrid iterative reconstruction (iDose⁴) and iterative model reconstruction (IMR)) in infants with congenital heart disease (CHD).

METHODS

Fifty-one infants with CHD who underwent cardiac CTA in our institution between December 2014 and March 2015 were included. The effective radiation doses were calculated. Imaging data were reconstructed using the FBP, iDose⁴ and IMR algorithms. Parameters of objective image quality (noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)); subjective image quality (overall image quality, image noise and margin sharpness); coronary artery visibility; and diagnostic accuracy for the three algorithms were measured and compared.

RESULTS

The mean effective radiation dose was 0.61±0.32 mSv. Compared to FBP and iDose⁴, IMR yielded significantly lower noise (P<0.01), higher SNR and CNR values (P<0.01), and a greater subjective image quality score (P<0.01). The total number of coronary segments visualized was significantly higher for both iDose⁴ and IMR than for FBP (P=0.002 and P=0.025, respectively), but there was no significant difference in this parameter between iDose⁴ and IMR (P=0.397). There was no significant difference in the diagnostic accuracy between the FBP, iDose⁴ and IMR algorithms (χ²=0.343, P=0.842).

CONCLUSIONS

For infants with CHD undergoing cardiac CTA, the IMR reconstruction algorithm provided significantly increased objective and subjective image quality compared with the FBP and iDose⁴ algorithms. However, IMR did not improve the diagnostic accuracy or coronary artery visualization compared with iDose⁴.

Third-generation dual-source 70-kVp chest CT angiography with advanced iterative reconstruction in young children: image quality and radiation dose reduction

BACKGROUND

Many technical updates have been made in multi-detector CT.

OBJECTIVE

To evaluate image quality and radiation dose of high-pitch second- and third-generation dual-source chest CT angiography and to assess the effects of different levels of advanced modeled iterative reconstruction (ADMIRE) in newborns and children.

MATERIALS AND METHODS

Chest CT angiography (70 kVp) was performed in 42 children (age 158 ± 267 days, range 1-1,194 days). We evaluated subjective and objective image quality, and radiation dose with filtered back projection (FBP) and different strength levels of ADMIRE. For comparison were 42 matched controls examined with a second-generation 128-slice dual-source CT-scanner (80 kVp).

RESULTS

ADMIRE demonstrated improved objective and subjective image quality (P < .01). Mean signal/noise, contrast/noise and subjective image quality were 11.9, 10.0 and 1.9, respectively, for the 80 kVp mode and 11.2, 10.0 and 1.9 for the 70 kVp mode. With ADMIRE, the corresponding values for the 70 kVp mode were 13.7, 12.1 and 1.4 at strength level 2 and 17.6, 15.6 and 1.2 at strength level 4. Mean CTDIvol, DLP and effective dose were significantly lower with the 70-kVp mode (0.31 mGy, 5.33 mGy*cm, 0.36 mSv) compared to the 80-kVp mode (0.46 mGy, 9.17 mGy*cm, 0.62 mSv; P < .01).

CONCLUSION

The third-generation dual-source CT at 70 kVp provided good objective and subjective image quality at lower radiation exposure. ADMIRE improved objective and subjective image quality.

Dual-Source Computed Tomography Evaluation of Children with Congenital Pulmonary Valve Stenosis

BACKGROUND

Despite dual-source computed tomography (DSCT) technology has been performed well on adults or infants with heart disease, specific knowledge about children with congenital pulmonary valve stenosis (PS) remained to be established.

OBJECTIVES

This original research aimed to establish a professional approach of DSCT performing technology on children and to assess the image quality performed by DSCT to establish a diagnostic evaluation for children with PS.

PATIENTS AND METHODS

Ninety-eight children with congenital PS referred to affiliated hospital of Jining medical college were recruited from October 2013 to March 2015. Participants were divided into four groups according to different ages (0 - 1, 1 - 3, 3 - 7, 7 - 14), or three groups according to different heart rates (< 90, 90 - 110, > 110). Image quality of pulmonary valves was assessed based on a four-point grading scale (1 - 4 points). Those cases achieving a score of ≥ 3 points were selected for further investigation, which played a critical role in our analysis. Correlation analysis was used to identify the effects of age and heart rate on image quality. Additionally, the results evaluated by DSCT were compared with those evaluated from the operation, further confirming the accuracy of DSCT.

RESULTS

Seventy-two cases (73.4%) achieved a score of ≥ 3 points based on pulmonary valve imaging, which were available for further diagnosis. There was a statistically significant difference (P < 0.05) between the four groups except 0 - 1 group and 1 - 3 group, 3 - 7 group and 7 - 14 group, and the image quality of elder group was higher than younger group. Image score was gradually decreased with increased heart rate (F = 19.05, P < 0.01). Heart rate was negatively correlated with pulmonary valve scores (r = -0.391, P < 0.001), while there was no correlation between age and scores (r = 0.185, P = 0.070). The number, shape, commissure, and opening status of pulmonary valves evaluated by DSCT were the same as the results of operation.

CONCLUSION

Heart rate serves a pivotal role in imaging quality of DSCT. DSCT provides a functional evaluation of children with congenital PS and consequently contributes to a theoretical basis for corresponding treatment protocols.

Feasibility of high-pitch dual-source low-dose chest CT: Reduction of radiation and cardiac artifacts

PURPOSE

To compare the radiation dose and image quality, focused mainly on cardiac pulsation artifact, between high-pitch low-dose chest computed tomography (HP-LDCT) and standard low-dose chest CT (LDCT).

PATIENTS AND METHODS

One hundred patients underwent HP-LDCT (50 patients) or LDCT (50 patients). Scan parameters were the same except for the pitch and gantry rotation time: 3.0 vs. 1.2 and 0.28s vs. 0.5s, respectively. Objective image noise at five regions and subjective image quality, such as noise, artifacts, cardiac pulsation artifacts, and overall diagnostic acceptability, were evaluated using a five-point scale. The significance level for all tests was set at P<0.05.

RESULTS

The dose-length products (DLPs) with HP-LDCT and LDCT were 90.2±4.3mGycm and 103.1±6.4mGycm, respectively (P<0.01). DLP of HP-LDCT showed a 13% reduction versus LDCT. Objective image noise was not significantly different. Cardiac pulsation artifacts showed a significant reduction on HP-LDCT (P<0.01). Other subjective image quality parameters of HP-LDCT were similar to those of LDCT. The overall diagnostic acceptability of HP-LDCT was better than that of LDCT (P<0.01).

CONCLUSIONS

HP-LDCT showed a 13% mean radiation dose reduction with no deterioration in image quality due to cardiac pulsation artifacts.

Dual-source computed tomography for evaluating pulmonary artery in pediatric patients with cyanotic congenital heart disease: Comparison with transthoracic echocardiography

PURPOSE

To evaluate the quantitative accuracy of dual-source computed tomography (DSCT) on measurements of pulmonary artery in pediatric patients with cyanotic congenital heart diseases (CCHDs) when compared with transthoracic echocardiography (TTE).

METHODS

Thirty-five patients (mean age: 27.88 ± 28.27 months) with CCHDs underwent DSCT and TTE for evaluating the diameter of the main pulmonary artery (MPA), right pulmonary artery (RPA), and left pulmonary artery (LPA). Surgical measurements were obtained and served as the reference standard. The agreement was tested by linear regression analysis, Pearson's correlation coefficient, and Bland-Altman analysis. The intra- and extracardiac malformations were also observed.

RESULTS

There was a markedly positive correlation between DSCT and surgical measurements of the MPA, RPA, and LPA (r=0.95-0.97; all p<0.001), although the overestimation of the measurements of MPA, RPA, and LPA (bias 0.15 ± 0.95, 0.31 ± 0.63 and 0.35 ± 0.68 mm, respectively) was observed. However, there was a moderate correlation between TTE and surgical measurements of MPA, RPA, and LPA (r=0.61-0.84; all p<0.001), and the underestimation of the measurements of MPA, RPA, and LPA (bias-1.20 ± 1.69, -1.80 ± 1.77, and -1.50 ± 2.30 mm, respectively) was observed. In addition, DSCT was more efficient in finding associated malformations than TTE (40/40 vs. 33/40).

CONCLUSIONS

As a reliable, noninvasive and radiation-save imaging modality, DSCT can provide more accurate pulmonary artery measurements than TTE in cardiac surgical procedures.

Coronary artery visibility in free-breathing young children on non-gated chest CT: impact of temporal resolution

BACKGROUND

Dual-source CT allows scanning of the chest with high pitch and high temporal resolution, which can improve the detection of proximal coronary arteries in infants and young children when scanned without general anesthesia, sedation or beta-blockade.

OBJECTIVE

To compare coronary artery visibility between higher and standard temporal resolution.

MATERIALS AND METHODS

We analyzed CT images in 93 children who underwent a standard chest CT angiographic examination with reconstruction of images with a temporal resolution of 75 ms (group 1) and 140 ms (group 2).

RESULTS

The percentage of detected coronary segments was higher in group 1 than in group 2 when considering all segments (group 1: 27%; group 2: 24%; P = 0.0004) and proximal segments (group 1: 37%; group 2: 32%; P = 0.0006). In both groups, the highest rates of detection were observed for the left main coronary artery (S1) (group 1: 65%; group 2: 58%) and proximal left anterior descending coronary artery (S2) (group 1: 43%; group 2: 42%). Higher rates of detection were seen in group 1 for the left main coronary artery (P = 0.03), proximal right coronary artery (P = 0.01), proximal segments of the left coronary artery (P = 0.02) and proximal segments of the left and right coronary arteries (P = 0.0006).

CONCLUSION

Higher temporal resolution improved the visibility of proximal coronary arteries in pediatric chest CT.

Horseshoe Lung Associated with Left Lung Hypoplasia: Case Report and Systematic Review of the Literature

Horseshoe lung (HL) is often associated with cardiovascular malformations such as scimitar syndrome and unilateral lung hypoplasia. In patients with HL, the hypoplastic lung is almost always located on the right side. Cases of HL with a hypoplastic left lung are extremely rare.

In this paper, we describe a case of a one-day-old boy with HL involving left lung hypoplasia and perform a systematic review of the literature on HL with left lung hypoplasia.

Only 10 cases of HL involving left lung hypoplasia have been reported in the literature. Most of those cases also exhibited cardiovascular malformations and pulmonary hypertension. There have not been any reported cases of HL involving left lung hypoplasia associated with scimitar syndrome.

HL involving left lung hypoplasia is rare and tends to be associated with pulmonary hypertension.

Assessment of Double Outlet Right Ventricle Associated with Multiple Malformations in Pediatric Patients Using Retrospective ECG-Gated Dual-Source Computed Tomography

Purpose

To evaluate the feasibility and diagnostic accuracy of retrospective electrocardiographically (ECG)-gated dual-source computed tomography (DSCT) for the assessment of double outlet right ventricle (DORV) and associated multiple malformations in pediatric patients.

Materials and Methods

Forty-seven patients <10 years of age with DORV underwent retrospective ECG-gated DSCT. The location of the ventricular septal defect (VSD), alignment of the two great arteries, and associated malformations were assessed. The feasibility of retrospective ECG-gated DSCT in pediatric patients was assessed, the image quality of DSCT and the agreement of the diagnosis of associated malformations between DSCT and transthoracic echocardiography (TTE) were evaluated, the diagnostic accuracies of DSCT and TTE were referred to surgical results, and the effective doses were calculated.

Results

Apart from DORV, 109 associated malformations were confirmed postoperatively. There was excellent agreement (κ = 0.90) for the diagnosis of associated malformations between DSCT and TTE. However, DSCT was superior to TTE in demonstrating paracardiac anomalies (sensitivity, coronary artery anomalies: 100% vs. 80.00%, anomalies of great vessels: 100% vs. 88.57%, separate thoracic and abdominal anomalies: 100% vs. 76.92%, respectively). Combined with TTE, DSCT can achieve excellent diagnostic performance in intracardiac anomalies (sensitivity, 91.30% vs. 100%). The mean image quality score was 3.70 ± 0.46 (κ = 0.76). The estimated mean effective dose was < 1 mSv (0.88 ± 0.34 mSv).

Conclusions

Retrospective ECG-gated DSCT is a better diagnostic tool than TTE for pediatric patients with complex congenital heart disease such as DORV. Combined with TTE, it may reduce or even obviate the use of invasive cardiac catheterization, and thus expose the patients to a much lower radiation dose.

ECG-synchronized CT angiography in 324 consecutive pediatric patients: spectrum of indications and trends in radiation dose

The aim of the study is to describe the spectrum of indications for pediatric ECG-synchronized CT angiography (CTA), the main determinants of radiation exposure, and trends in radiation dose over time at a single, tertiary referral center. The study was IRB approved and HIPAA compliant with informed consent waived. Between 2005 and 2013, 324 pediatric patients underwent ECG-synchronized CTA to evaluate known or suspected cardiovascular abnormalities (109 female, median age 8.1 years). The effective dose (ED) was calculated using age-specific correction factors. Univariate and multivariate regression analyses were performed to identify predictors of radiation dose. The most common primary indications for the CTA examinations included known or suspected coronary pathologies (n = 166), complex congenital heart disease (n = 73), and aortic pathologies (n = 41). Median radiation exposure decreased from 12 mSv for patients examined in the years 2005-2007 to 1.2 mSv for patients examined in the years 2011-2013 (p < 0.001). Patients scanned using a tube potential of 80 kV (n = 259) had a significantly lower median radiation dose (1.4 mSv) compared to patients who were scanned at 100 kV (n = 46, median 6.3 mSv) or 120 kV (n = 19, median 19 mSv, p < 0.001). Tube voltage, followed by tube current and the method of ECG-synchronization were the strongest independent predictors of radiation dose. Growing experience with dose-saving techniques and CTA protocols tailored to the pediatric population have led to a tenfold reduction in radiation dose over recent years and now allow routinely performing ECG-synchronized CTA in children with a radiation dose on the order of 1 mSv.

Coronary artery imaging in children

Coronary artery problems in children usually have a significant impact on both short-term and long-term outcomes. Early and accurate diagnosis, therefore, is crucial but technically challenging due to the small size of the coronary artery, high heart rates, and limited cooperation of children. Coronary artery visibility on CT and MRI in children is considerably improved with recent technical advancements. Consequently, CT and MRI are increasingly used for evaluating various congenital and acquired coronary artery abnormalities in children, such as coronary artery anomalies, aberrant coronary artery anatomy specific to congenital heart disease, Kawasaki disease, Williams syndrome, and cardiac allograft vasculopathy.

Application of prospective ECG-gated high-pitch 128-slice dual-source CT angiography in the diagnosis of congenital extracardiac vascular anomalies in infants and children

PURPOSE

To investigate the value of prospective ECG-gated high-pitch 128-slice dual-source CT (DSCT) angiography in the diagnosis of congenital extracardiac vascular anomalies in infants and children in comparison with transthoracic echocardiography (TTE).

METHODS

Eighty consecutive infants or children clinically diagnosed of congenital heart disease and suspected with extracardiac vascular anomaly were enrolled, and 75 patients were finally included in this prospective study. All patients underwent prospective ECG-gated high-pitch DSCT angiography after TTE with an interval of 1-7 days. The diagnostic accuracy and sensitivity of high-pitch DSCT angiography and TTE were compared according to the surgical/CCA findings. The image quality of DSCT was assessed using a five-point scale. The effective radiation dose (ED) was calculated.

RESULTS

A total of 17 congenital heart diseases and 162 separate extracardiac vascular anomalies were confirmed by surgical/CCA findings in 75 patients. The diagnostic accuracy of high-pitch DSCT angiography and TTE was 99.67% and 97.89%, respectively. The sensitivity of high-pitch DSCT angiography and TTE was 97.53% and 79.62%, respectively. There was significant difference regarding to the diagnostic accuracy and the sensitivity between high-pitch DSCT angiography and TTE (χ2 = 23.561 and 28.013, P<0.05). The agreement on the image quality scoring of DSCT between the two observers was excellent (κ = 0.81), and the mean score of image quality was 4.1±0.7. The mean ED of DSCT was 0.29±0.08 mSv.

CONCLUSIONS

Prospective ECG-gated high-pitch 128-slice DSCT angiography with low radiation dose and high diagnostic accuracy has higher sensitivity compared to TTE in the detection of congenital extracardiac vascular anomalies in infants and children.

Accuracy, image quality, and radiation dose of prospectively ECG-triggered high-pitch dual-source CT angiography in infants and children with complex coarctation of the aorta

RATIONALE AND OBJECTIVES

To evaluate the diagnostic accuracy, image quality, and radiation dose of prospective electrocardiogram (ECG)-triggered high-pitch dual-source computed tomography (DSCT) in infants and young children with complex coarctation of the aorta (CoA).

MATERIALS AND METHODS

Forty pediatric patients aged < 4 years with suspected CoA underwent prospective ECG-triggered high-pitch DSCT angiography and transthoracic echocardiography (TTE). Surgery and/or conventional cardiac angiography (CCA) were performed in all patients. The diagnostic accuracy of DSCT angiography and TTE was compared to the surgical and/or CCA findings. The causes of misdiagnosis and miss were analyzed, and the advantages and limitation of both imaging modalities were evaluated. Image quality of DSCT was evaluated, and effective radiation dose was calculated.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy of DSCT in evaluation of complex CoA were 92.37%, 98.51%, 97.32%, 93.57%, and 96.25%, respectively. There was a significant difference in the accuracy between DSCT and TTE (χ² = 9.9, P＜.05). For a total of 80 extracardiac anomalies, the sensitivity (98.8%, 79/80) of DSCT was greater than that of TTE (62.5%; 50 of 80). On the contrary, for 38 cardiac anomalies, the sensitivity (78.9%, 30 of 38) of DSCT was lesser than that of TTE (100%; 38 of 38). The mean score of image quality was 4.27 ± 0.73. The mean effective radiation dose was 0.20 ± 0.09 mSv.

CONCLUSIONS

Prospective ECG-triggered high-pitch DSCT may be a clinical feasible modality in the evaluation of pediatric patients with complex CoA, providing adequate image quality, high diagnostic accuracy, and low radiation dose.

Imaging in congenital pulmonary vein anomalies: the role of computed tomography

Pulmonary venous anomalies comprise a wide spectrum of anatomical variations and their clinical presentations may vary from the relatively benign single partial anomalous pulmonary venous connection (PAPVC) to the critical obstructed total anomalous pulmonary venous connection (TAPVC). We briefly review the common anomalies encountered, while highlighting the utility that computed tomographic angiography (CTA) provides for this spectrum of extracardiac vascular malformations and connections. CTA has established itself as an invaluable imaging modality in these patients. A detailed knowledge of the CTA imaging findings in pulmonary venous anomalies is crucial to guide clinical decision-making in these patients.