Pediatric Cardiac CT Research Articles

Improving Reproducibility of Volumetric Evaluation Using Computed Tomography in Pediatric Patients with Congenital Heart Disease.

The volumetric data obtained from the cardiac CT scan of congenital heart disease patients is important for defining patient's status and making decision for proper management. The objective of this study is to evaluate the intra-observer, inter-observer, and interstudy reproducibility of left ventricular (LV) and right ventricular (RV) or functional single-ventricle (FSV) volume. And compared those between manual and using semi-automated segmentation tool. Total of 127 patients (56 female, 71 male; mean age 82.1months) underwent pediatric protocol cardiac CT from January 2020 to December 2022. The volumetric data including both end-systolic and -diastolic volume and calculated EF were derived from both conventional semiautomatic region growing algorithms (CM, TeraRecon, TeraRecon, Inc., San Mateo, CA, USA) and deep learning-based annotation program (DLS, Medilabel, Ingradient, Inc., Seoul, Republic of Korea) by three readers, who have different background knowledge or experience of radiology or image extraction before. The reproducibility was compared using intra- and inter-observer agreements. And the usability was measured using time for reconstruction and number of tests that were reconfigured before the reconfiguration time was reduced to less than 5min. Inter- and intra-observer agreements showed better agreements degrees in DLS than CM in all analyzers. The time used for reconstruction showed significantly shorter in DLS compared with CM. And significantly small numbers of tests before the reconfiguration is needed in DLS than CM. Deep learning-based annotation program can be more accurate way for measurement of volumetric data for congenital heart disease patients with better reproducibility than conventional method.

A Smart Approach: Utilizing A Quality Improvement Toolkit To Develop Pediatric And Congenital Cardiac CT Services In A Low-resource Setting

A Smart Approach: Utilizing A Quality Improvement Toolkit To Develop Pediatric And Congenital Cardiac CT Services In A Low-resource Setting

Diagnostic Reference Levels in Pediatric Cardiac CT Imaging: A Literature Review

Diagnostic Reference Levels in Pediatric Cardiac CT Imaging: A Literature Review

PEDS10: Characterizing the Fit of Transvalvular Left Ventricular Micro-Axial Flow Pumps in Pediatric Patients

Background: There are few FDA approved mechanical circulatory support (MCS) devices for pediatric patients. Physicians in the US and Europe have increasingly elected to use the Impella platform to support pediatric patients including use in axillary arteries with diameters as small as 4.8 mm for the Impella 5.5 with SmartAssist (21 F) without complication. Given the increasing use of these devices in pediatric patients, there is a need to quantify and characterize the device fit in this population. Methods: 3D anatomical reconstructions were built from pediatric cardiac CT scans (n=23, age 0.8-9.3 years, BSA 0.45-1.09 m2). The length of the left ventricle & ascending aorta and the diameters of the brachiocephalic & lower left subclavian arteries were measured via clinical CT practices and modeled as a scalar relationship to BSA using simple linear regression & bounded by critical Impella dimensions to evaluate transvalvular fit. Estimated distal artery diameters were calculated via published vessel models to evaluate intravascular device delivery potential. The models were tested on pediatric Impella patient data as reported in published case studies (n=27, age 4-19 years, BSA 0.91-2.38 m2). Results: CT scan reconstructions suggest sufficient LV length in 0.6 m2 and 1.2 m2 BSA patients for Impella 5.5 and Impella CP, respectively. For direct aortic implant, BSA >1.1 m2 may be required due to ascending aortic length. The ostial segments of the brachiocephalic and left subclavian arteries were of adequate size for Impella 5.5 in patients with BSA as small as 0.53 m2. Published models correlating vessel diameter with BSA suggest BSA >0.86 m2 and >1.15 m2 patients could fit Impella CP and Impella 5.5, respectively, via midclavicular axillary access. Modeled vessel diameters predict that all pediatric Impella patients evaluated (27/27) would fit an Impella CP, and 74% (20/27) would fit an Impella 5.5 compared with the minimum vessel size reported in the literature. Conclusions: These analyses outline critical parameters for current Impella devices to fit pediatric patients. Further characterization of pediatric vessel sizes based on readily available clinical metrics such as BSA may aid physician decisions for MCS use in patients in critical need.

Review of the Asian Consortium on Radiation Dose of Pediatric Cardiac CT (ASCI-REDCARD) and Recommendations for a New Edition

Review of the Asian Consortium on Radiation Dose of Pediatric Cardiac CT (ASCI-REDCARD) and Recommendations for a New Edition

Pediatric Cardiac CT and MRI: Considerations for the General Radiologist.

OBJECTIVE. This article reviews the use and current imaging techniques of cardiac CT angiography and cardiac MRI in the evaluation of commonly encountered pediatric cardiac processes that may present to the general radiologist. CONCLUSION. Imaging pediatric patients with acquired and congenital heart disease is an important skill for general radiologists. As survival rates increase and these patients enter adulthood, knowledge of pediatric acquired and congenital heart disease remains pertinent.

Visualization of proximal coronary arteries on high-pitch electrocardiogram-triggered computed tomography in pediatric congenital heart disease: effects of heart rate and body surface area.

As CT technology has advanced, techniques for pediatric cardiac CT in congenital heart disease have evolved from retrospective electrocardiography (ECG)-gating with relatively high radiation doses to lower-dose prospective ECG-gating and even single-beat gated scans. Despite these advances, coronary artery imaging in children remains challenging because of their small vessel size and high heart rates, often necessitating retrospective gating. Evaluate coronary artery visualization in pediatric patients (<20years) who underwent low-dose high-pitch ECG-triggered scans and stratify the probability of coronary artery visualization based upon heart rate and body surface area (BSA). Two hundred eleven high-pitch ECG-triggered studies from April 2014 to November 2017 were reviewed by two pediatric cardiac imagers in this retrospective study. Patient age, gender, BSA, average heart rate, heart rate variability and use of general anesthesia were recorded as well as dose-length product (DLP) and volumetric CT dose index (CTDIvol). We assessed the coronary artery score using a 5-point scale, with score of ≥3 considered of diagnostic quality. We performed multivariate statistical analysis including logistic regression to analyze effects of heart rate and BSA. Patient age range was 1day to 19years (median age 3years). Heart rate range was 49-188 beats per minute (bpm; median 122bpm) and BSA range was 0.15-2.07m2 (median 0.53m2). The origin and proximal coronary arteries were confidently seen (score ≥3) in 61% of studies in this cohort. Coronary artery visualization scores further increased with increased BSA (P<0.002) and with decreased heart rate (P<0.001). At heart rates <100bpm or in patients with BSA>0.58, adequate coronary artery visualization was present 72% of the time. While in many patients the coronary artery origins are visualized using high-pitch ECG-triggered technique, the importance of coronary artery visualization needs to be weighed with the radiation dose penalty in individual patients to achieve optimal imaging.

Evaluation of the Availability of the Wide Coverage Volume Axial Mode in Pediatric Cardiac CT

Evaluation of the Availability of the Wide Coverage Volume Axial Mode in Pediatric Cardiac CT

Pediatric 320-row cardiac computed tomography using electrocardiogram-gated model-based full iterative reconstruction

BackgroundFull iterative reconstruction algorithm is available, but its diagnostic quality in pediatric cardiac CT is unknown.ObjectiveTo compare the imaging quality of two algorithms, full and hybrid iterative reconstruction, in pediatric cardiac CT.Materials and methodsWe included 49 children with congenital cardiac anomalies who underwent cardiac CT. We compared quality of images reconstructed using the two algorithms (full and hybrid iterative reconstruction) based on a 3-point scale for the delineation of 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. We evaluated beam-hardening artifacts from contrast-enhancement material using a 3-point scale, and we evaluated the overall image quality using a 5-point scale. We also compared image noise, signal-to-noise ratio and contrast-to-noise ratio between the algorithms.ResultsThe overall image quality was significantly higher with full iterative reconstruction than with hybrid iterative reconstruction (3.67±0.79 vs. 3.31±0.89, P=0.0072). The evaluation scores for most of the gross structures were higher with full iterative reconstruction than with hybrid iterative reconstruction. There was no significant difference between full and hybrid iterative reconstruction for the presence of beam-hardening artifacts. Image noise was significantly lower in full iterative reconstruction, while signal-to-noise ratio and contrast-to-noise ratio were significantly higher in full iterative reconstruction.ConclusionThe diagnostic quality was superior in images with cardiac CT reconstructed with electrocardiogram-gated full iterative reconstruction.

Asian consortium on radiation dose of pediatric cardiac CT (ASCI-REDCARD).

With incremental utilization of pediatric cardiac CT in congenital heart disease, it is imperative to define its current radiation dose levels in clinical practice in order to help imagers optimize CT protocols, particularly in Asia and other developing countries where CT physicists are not readily available. To evaluate current radiation dose levels and influencing factors in cardiac CT in children with congenital heart disease in Asia by conducting a retrospective multi-center, multi-vendor study. We included 1,043 pediatric cardiac CT examinations performed in 8 centers between January 2014 and December 2014 to evaluate congenital heart disease. In five weight groups, we calculated radiation dose metrics including volume CT dose index, size-specific dose estimate, dose-length product and effective dose. Age at CT exam, gender, tube voltage, scan mode, CT indication and image reconstruction algorithm were analyzed to learn whether they influenced CT radiation dose. Volume CT dose index, size-specific dose estimate, dose-length product and effective dose of pediatric cardiac CT showed variations in the range of 4.3-23.8mGy, 4.9-17.6mGy, 55.8-501.3mGy∙cm and 1.5-3.2mSv, respectively, within five weight groups. Gender, tube voltage, scan mode and cardiac function assessment significantly influenced CT radiation dose. This multi-center, multi-vendor study demonstrated variations in radiation dose metrics of pediatric cardiac CT reflecting current practice in Asia. Gender, tube voltage, scan mode and cardiac function assessment should be considered as essential radiation dose-influencing factors in developing optimal pediatric cardiac CT protocols.

Subjective and objective image differences in pediatric computed tomography cardiac angiography using lower iodine concentration.

Several recent studies showed the optimal contrast enhancement with a low-concentration and iso-osmolar contrast media in both adult and pediatric patients. However, low contrast media concentrations are not routinely used due to concerns of suboptimal enhancement of cardiac structures and small vessels. To evaluate the feasibility of using iso-osmolar contrast media containing a low iodine dose for CT cardiac angiography at 80kilovolts (kVp) in neonates and infants. The iodixanol 270 group consisted of 79 CT scans and the iopromide 370 group of 62 CT scans in patients ≤1year old. Objective measurement of the contrast enhancement was analyzed and contrast-to-noise ratios of the ascending aorta and left ventricle were calculated. Regarding subjective measurement, a four-point scale system was devised to evaluate degrees of contrast enhancement, image noise, motion artifact and overall image quality of each image set. Reader performance for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment was evaluated. Group objective and subjective measurements were nonsignificantly different. Overall sensitivity, specificity and diagnostic accuracy for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment were 42.8%, 59%, and 50%, respectively. The application of iodixanol 270 achieved optimal enhancement for performing pediatric cardiac CT angiography at 80kVp in neonates and infants. Objective measurements of contrast enhancement and subjective image quality assessments were not statistically different in the iodixanol 270 and iopromide 370 groups.

Estimating Effective Dose of Radiation From Pediatric Cardiac CT Angiography Using a 64-MDCT Scanner: New Conversion Factors Relating Dose-Length Product to Effective Dose.

The purpose of this study is to determine the conversion factors that enable accurate estimation of the effective dose (ED) used for cardiac 64-MDCT angiography performed for children. Anthropomorphic phantoms representative of 1- and 10-year-old children, with 50 metal oxide semiconductor field-effect transistor dosimeters placed in organs, underwent scanning performed using a 64-MDCT scanner with different routine clinical cardiac scan modes and x-ray tube potentials. Organ doses were used to calculate the ED on the basis of weighting factors published in 1991 in International Commission on Radiological Protection (ICRP) publication 60 and in 2007 in ICRP publication 103. The EDs and the scanner-reported dose-length products were used to determine conversion factors for each scan mode. The effect of infant heart rate on the ED and the conversion factors was also assessed. The mean conversion factors calculated using the current definition of ED that appeared in ICRP publication 103 were as follows: 0.099 mSv · mGy-1 · cm-1, for the 1-year-old phantom, and 0.049 mSv · mGy-1 · cm-1, for the 10-year-old phantom. These conversion factors were a mean of 37% higher than the corresponding conversion factors calculated using the older definition of ED that appeared in ICRP publication 60. Varying the heart rate did not influence the ED or the conversion factors. Conversion factors determined using the definition of ED in ICRP publication 103 and cardiac, rather than chest, scan coverage suggest that the radiation doses that children receive from cardiac CT performed using a contemporary 64-MDCT scanner are higher than the radiation doses previously reported when older chest conversion factors were used. Additional up-to-date pediatric cardiac CT conversion factors are required for use with other contemporary CT scanners and patients of different age ranges.

Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography.

Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. We optimized the iteration level of iDose4 and evaluated image quality for pediatric cardiac CT angiography. Children (n = 160) with congenital heart disease were enrolled and divided into full-dose (n = 84) and half-dose (n = 76) groups. Four series were reconstructed using FBP, and iDose4 levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose4-optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student's t-test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Mean scores for iDose4 level 4 were the best in both dose groups (all P < 0.05). CNR was improved in both groups with iDose4 level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6-96.2% (no statistical difference). iDose4 level 4 was optimal for both the full- and half-dose groups. Protocols with iDose4 level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy.

Effect of the forward-projected model-based iterative reconstruction solution algorithm on image quality and radiation dose in pediatric cardiac computed tomography.

Some iterative reconstruction algorithms are useful for reducing the radiation dose in pediatric cardiac CT. A new iterative reconstruction algorithm (forward-projected model-based iterative reconstruction solution) has been developed, but its usefulness for radiation dose reduction in pediatric cardiac CT is unknown. To investigate the effect of the new algorithm on CT image quality and on radiation dose in pediatric cardiac CT. We obtained phantom data at six dose levels, as well as pediatric cardiac CT data, and reconstructed CT images using filtered back projection, adaptive iterative dose reduction 3-D (AIDR 3-D) and the new algorithm. We evaluated phantom image quality using physical assessment. Four radiologists performed visual evaluation of cardiac CT image quality. In the phantom study, the new algorithm effectively suppressed noise in the low-dose range and moderately generated modulation transfer function, yielding a higher signal-to-noise ratio compared with filtered back projection or AIDR 3-D. When clinical cardiac CT was performed, images obtained by the new method had less perceived image noise and better tissue contrast at similar resolution compared with AIDR 3-D images. The new algorithm reduced image noise at moderate resolution in low-dose CT scans and improved the perceived quality of cardiac CT images to some extent. This new algorithm might be superior to AIDR 3-D for radiation dose reduction in pediatric cardiac CT.

Assessment of an iterative reconstruction algorithm (SAFIRE) on image quality in pediatric cardiac CT datasets

Pediatric cardiac patients often undergo repeat diagnostic testing, resulting in relatively high cumulative medical radiation exposure. Low-dose CT scanning techniques used to decrease radiation exposure may result in reduced image quality. This study evaluates a prototype iterative reconstruction algorithm, sinogram-affirmed iterative reconstruction (SAFIRE), to determine the effect on qualitative and quantitative measures of image quality in pediatric cardiac CT datasets, compared with a standard weighted filtered back projection (wFBP) algorithm. Seventy-four datasets obtained on a 128-slice dual-source CT system were evaluated for image quality using both the wFBP and the prototype iterative reconstruction algorithm. Contrast, noise, contrast-to-noise ratio, signal-to-noise ratio, and qualitative image quality were compared between groups. Data were analyzed as medians and 25th and 75th percentiles, and groups were compared with the use of the Wilcoxon singed-rank test or k sample equality of medians test. There was a 34% decrease in noise, a 41% increase in contrast-to-noise ratio, and a 56% increase in signal-to-noise ratio in the prototype iterative reconstruction, compared with wFBP. All differences were statistically significant (P < 0.001). Qualitative measures of image noise and noise texture were also improved in the iterative reconstruction group (P < 0.001 for both). Diagnostic confidence was similar between reconstruction techniques. Median scan dose length product was 15.5 mGy · cm. The prototype iterative reconstruction algorithm studied significantly reduces image noise and improves qualitative and quantitative measures of image quality in low-dose pediatric CT datasets, compared with standard wFBP.

Strategies for Dose-Optimized Imaging in Pediatric Cardiac Dual Source CT

As a result of rapid advances in CT technology, including dual source CT, cardiac CT exams at high heart rates are feasible, making pediatric cardiac CT in congenital heart disease possible. Dose concerns and patient size variability make general recommendations difficult. The aim of this study was to investigate which scanner settings are suitable for multiple weight groups to provide dose-optimized scanning. All 12 patients underwent a contrast-enhanced gated dual source CT exam. A maximum of 2 ml/kg body weight or 60 ml contrast was applied. Scanner settings at 80 and 120 kV, as well as weight-adapted mAs settings were used in an iterative fashion. Datasets were assessed for image quality and dose-optimized scan parameters were established via class comparison. In a final step a table was created as a recommendation for cardiac CT in children corresponding to their body weight. Strategies for optimized contrast application with hand vs. manual injection were explored. In all children diagnostic image quality was obtained. In children < 60 kg, 80 kV can be used, in all others 100 kV is sufficient. The eff. mAs varied from 362 mAs to 30 mAs depending on body weight. Retrospectively a significant dose reduction would have been possible in 6 / 12 patients. Cardiac CT can be performed between 0.6 and 3.2 mSv in a pediatric population. The present study shows that dual source cardiac CT is a potential diagnostic alternative in children with congenital heart disease without excessive radiation exposure or contrast media application.

Safety in pediatric MR and cardiac CT

Safety in pediatric MR and cardiac CT

Giant Aortic Aneurysm After Patch Repair of Coarctation

A 31-year-old asymptomatic man was seen by a cardiologist for a routine examination. Eighteen years previously, at the age of 13 years, the patient had undergone a Dacron aortoplasty for aortic coarctation. Findings from the clinical examination and transthoracic echocardiography were normal; the exercise test revealed ST-segment depression not associated with angina. A chest x-ray was performed, which depicted a huge ballooning of the descending …