64-slice multidetector-row computed tomographic angiography for evaluating congenital heart disease

Comparison of non-invasive assessment for pulmonary vascular indices by two-dimensional echocardiography and cardiac computed tomography angiography with conventional catheter angiocardiography in unrepaired Tetralogy of Fallot physiology patients weighing more than 10 kg: a retrospective analysis

AIMS

Assessment of pulmonary vascular dimensions (PVDs) in Tetralogy of Fallot (TOF) is an integral part of planning transcatheter and surgical interventions. We sought to examine the reliability and correlation of echocardiography (ECHO) and computed tomography angiography (CTA) measurements with those obtained by cardiac catheterization and angiography (CCA).

METHODS AND RESULTS

Tetralogy of Fallot physiology patients undergoing ECHO, CTA, and CCA within a month prior to surgical correction during 2018-2020 were retrospectively enrolled. Indexed diameter of pulmonary annulus (iPAnn), indexed right pulmonary artery (iRPA), indexed left pulmonary artery (iLPA) and indexed descending aorta (iDA) were measured using ECHO and CTA followed by derivation of Nakata index (NI), McGoon's ratio (MGR), ratio of predicted peak right ventricular (RV) and left ventricular (LV) pressures (pRV/pLV) and Z-scores. Comparison with CCA-derived measurements was made and correlational equations were subsequently deduced. Pulmonary vascular dimensions for 54 patients with mean age of 15.5 ± 9.3 years (range: 3-34 years) were analysed. Computed tomography angiography and CCA measurements for iPAnn, iRPA, NI, MGR, pRV/pLV, and Z-score were comparable with each other while ECHO parameters were significantly lower than CCA. However, iLPA diameter was significantly underestimated by ECHO and overestimated by CTA. Correlational analysis showed stronger correlation between CTA- and CCA-derived PVD as against ECHO measurements except for iDA, pRV/pLV, and Z-score.

CONCLUSIONS

For unrepaired TOF physiology patients weighing more than 10 kg, CTA-acquired PVD are reliable and comparable with CCA except for DA for which ECHO is non-inferior. Non-invasive modalities though are inferior to CCA for LPA sizing. Utilizing derived equations, precise estimation of PVD can be carried out using non-invasive tools.

320 cardiac MDCT angiography in preoperative assessment of TOF and its variants: Does it worth it?

Background

Tetralogy of Fallot is the most common cyanotic congenital heart disease encountering a large spectrum of anatomical presentations with differing surgical approaches, and long-term outcomes ranging from ventricular septal defect with limited aortic overriding and mild pulmonary obstruction to a critical form of VSD and pulmonary atresia. TOF variants include PA/VSD, TOF/CAVC, TOF/DORV and TOF with absent pulmonary valve. Also, it may be accompanied with many associated intracardiac and extracardiac anomalies that may be of value when imaging and planning the surgical procedure.

Results

Our study included 22 cases of classic TOF, 18 with PA/VSD (12 were of type A, 5 were of type B and 1 was of type C), 3 with TOF/CAVC and 7 TOF/DORV. Sub-valvular RVOTO was detected in 94% of patients. A statistically significant difference was depicted between Echocardiography and MDCT in detecting supravalvular RVOTO, however no statistically significant difference was found in sub-valvular and valvular RVOTO detection. MDCT could efficiently characterize pulmonary arterial tree with statistically significant difference between both Echocardiography and MDCT in assessment of main, right and left pulmonary arteries with P value = 0.036,0.014 and 0.023 respectively. With calculation of Mc-Goon ratio in all patients, it was favorable (> 1.2) in 33 patients (66%). MDCT entailed 19 patients with PDA versus 15 depicted by Echocardiography and 25 MAPCAs per 11patients compared 8 MAPCAs per 7 patients detected by Echocardiography. Right sided aortic arch was found in 10 patients and 24 patients showed abnormal branching pattern. Coronary artery abnormalities were identified in eight patients. MDCT showed 100% sensitivity and 100% specificity in depicting aortic, coronary and other associated extracardiac vascular anomalies.

Conclusion

MDCT offers comprehensive anatomical assessment of TOF, and its variants providing superiority over echocardiography and comparable results to cardiac catherization with 100% sensitivity and specificity in evaluation of associated extracardiac vascular anomalies as well as pulmonary arteries characterization. It is worth using MDCT routinely in combination with echocardiography for the preoperative assessment of TOF and its variants representing a less invasive option than conventional catherization with lower radiation exposure.

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.

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.

Image quality and radiation dose of dual-source CT cardiac angiography using prospective ECG-triggering technique in pediatric patients with congenital heart disease

Background

All studies involving use of ionizing radiation should be performed in accordance with the ALARA (As Low As Reasonably Achievable) principle, especially in children. In this study, the prospective ECG triggering technique with low voltage was used in dual-source computed tomography (DSCT) angiography to investigate if image quality with low radiation dose could be satisfactory in pediatric patients with congenital heart disease.

Methods

Sixty pediatric patients with suspected congenital cardiovascular anomalies were enrolled prospectively in the study. They were randomly assigned to two groups for DSCT angiography. Group A were scanned by prospective ECG-triggering computed tomography angiography (CTA) with 80 kV tube voltage, while group B by used non-ECG-gated CTA with the same tube voltage. The anomaly accuracy was evaluated based on the surgical and/or conventional cardiac angiography findings. The overall image quality was assessed on a five-point scale. And the diagnostic accuracy and radiation dose was evaluated in both groups.

Results

There were 127 cardiovascular anomalies in Group A and 108 in Group B. The mean subjective image quality and diagnostic accuracy between these two groups were significantly different (P = 0.007 and 0.011, respectively). The mean effective dose in Group A and Group B was 0.38 ± 0.13 mSv and 0.35 ± 0.17 mSv, respectively. But there was no significant difference between two groups (P = 0.197).

Conclusions

The prospective ECG triggering technique in DSCT scan can offer better image quality and diagnostic accuracy with low radiation exposure in pediatric patients with congenital heart diseases. This technique has potential to become a new clinical routine in pediatric cardiac computed tomography (CT) imaging.

Computed tomography imaging in children with congenital heart disease: Indications and radiation dose optimization

Computed tomography (CT) technology is acquiring a key role in the diagnostic process of complex cardiac congenital anomalies. Recent advances and improvements in spatial and temporal resolution and radiation dose are encouraging the use of CT scanning in children. Paediatric cardiologists should have a good knowledge of the potential of CT techniques and their limitations to plan and properly perform CT examinations without forgetting radiation concerns. In this paper, we will discuss the principal indications for CT scans in newborns and children in our clinical practice. We will also outline the most-used strategies for dose reduction. Basic knowledge about the various CT techniques is crucial, not only to perform, but also to interpret CT results, thus helping the medical and surgical management of patients.

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.

Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery: Diagnoses and Surgical Results in 12 Pediatric Patients

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo-8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.

Korean guidelines for the appropriate use of cardiac CT

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease.

Usefulness of 64-detector computed tomography in the diagnosis and management of patients with congenital heart disease

INTRODUCTION AND OBJECTIVES

Although congenital heart defects are the most common major congenital abnormalities, the associated mortality has been decreasing due to improvements in their diagnosis and treatment. We assessed the usefulness of 64-multidetector computed tomography in the diagnosis and management of these patients.

METHODS

This 5-year observational, analytical, retrospective, cohort study included a total of 222 tomographic studies of patients with congenital heart disease. Computed tomography scans were read twice and medical records were reviewed. We assessed the complexity of the disease, patient, and radiological technique, and evaluated the contribution of new data in relation to clinical suspicion and diagnostic change. A confidence interval was set at 95% and a P value of<.05 was used as the cutoff for statistical significance.

RESULTS

In 35.1% of patients, the treatment procedure was performed after computed tomography without other tests. Additional diagnostic catheterization was performed in 12.5% of patients. There were new findings in 77% of patients (82.9% with complex disease), which prompted a change in patient management in 35.6%. All unexpected reports described new findings. No significant differences were found by age, sex, study period, urgency of the test order, patient complexity, or difficulty of the technique.

CONCLUSIONS

Use of 64-detector computed tomography yields good diagnostic performance in congenital heart disease, prompts changes in management in more than one-third of patients, and reveals new findings in relation to the presumed diagnosis in 77% of patients.

Low-dose prospectively electrocardiogram-gated axial dual-source CT angiography in patients with pulsatile bilateral bidirectional Glenn Shunt: an alternative noninvasive method for postoperative morphological estimation

OBJECTIVE

To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA) in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG) as an alternative noninvasive method for postoperative morphological estimation.

METHODS

Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years) underwent both low-dose PGA scanning and conventional cardiac angiography (CCA) for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC) and pulmonary artery (PA), the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland-Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated.

RESULTS

The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P<0.001) was observed between the measurements on CTA images and on CCA images. Bland-Altman analysis demonstrated a systematic overestimation of the measurements by CTA (the mean value of bias>0).The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively.

CONCLUSION

CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG.

Rheumatic mitral stenosis associated with sinus venosus atrial septal defect and partial anomalous pulmonary venous return

In medical literature, the association of acquired and congenital heart disease is interestingly well known, but uncommon. We report a case of young male adult whose therapeutic management for rheumatic mitral stenosis is changed as sinus venosus atrial septal defect was detected by transesophageal echocardiography. Presence of partial anomalous pulmonary venous return of right superior pulmonary vein into the superior vena cava detected in transesophageal echocardiography was confirmed at the operation which was successfully carried out to correct all three abnormalities through the right atrial approach.

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

To investigate the clinical significance of the application of 320-row CT angiography with low-dose prospective ECG-triggered target scanning in children with complex congenital heart disease (CHD), and to compare with the results from transthoracic echocardiography (TTE). 22 patients (male 12 cases, female 10 cases, average age: 18 months, range: 14 days-9 years, average weight: 13 kg) received an examination through 320-row CT angiography with low-dose prospective ECG-triggered volume target scan mode and transthoracic echocardiography. The center of phase window for data collection in this study was set to 40% of the R-R interval. Of these, 18 patients received surgery and 4 patients received conventional cardiac angiography (CCA). The diagnostic accuracy of 320-row CTA was calculated according to the examination results from surgical and/or cardiac angiography. The overall quality score for CTA images was divided into five levels. The results were compared with the research data of radiation doses obtained from patients with congenital heart disease who had received CT angiography. Complex congenital heart disease was confirmed by surgical or CCA in each of 22 patients, with 42 cases of large vascular malformations outside the heart cavity, and 26 of intracardiac malformations. The diagnostic accuracy of 320-row CT angiography and transthoracic echocardiography for large vascular malformation outside the heart cavity was 95.2 and 80.9%, respectively; for intracardiac malformation the accuracy was 88.5 and 100.0%, respectively. There was significant difference between 320-row CT and transthoracic echocardiography in the diagnosis of large vascular malformation outside the heart cavity (P < 0.05) with better results in 320-row CT, and no significant difference was found in the diagnosis of intracardiac malformation (P > 0.05). The average subjective image quality score was 4.4 ± 0.7 points. The average effective dose was 0.42 ± 0.08 mSv. 320-row CT enables direct visualization of the vascular configuration and shape of the aorta, pulmonary artery, and other large vessels to diagnose extracardiac vascular malformations. Combined with transthoracic echocardiography, 320-row CT is a promising technology that may be able to replace catheter based angiography to evaluate congenital cardiovascular malformations.

Computed tomographic angiography in tetralogy of Fallot

Echocardiography is often inadequate for imaging tetralogy of Fallot, prompting cineangiography. This study prospectively evaluated multidetector computed tomographic angiography for preoperative evaluation of tetralogy of Fallot in 112 consecutive patients. Forty-eight had nonconfluent or hypoplastic pulmonary arteries (mean z-score, −2; range, −11.1–0.13) permitting only palliative or no surgery; 64 had adequate pulmonary artery anatomy (mean z-score, 0.59; range,−2.53–3.4) allowing total repair. The surgical data of 50 patients who underwent total correction were compared with transthoracic echocardiography and multidetector computed tomographic angiography findings. Multidetector computed tomographic angiography tended to reveal unsuspected collaterals and coronary abnormalities besides outlining the right ventricular outflow tract and pulmonary artery branches. The branch pulmonary artery diameter z-score was the most important determinant of surgical strategy, with the worst figures being associated with no surgical options or palliative surgery, and the best figures leading to corrective surgery. The mean radiation dose was 3.45 mSv. Multidetector computed tomographic angiography is a powerful supplement to echocardiography in the preoperative evaluation of tetralogy of Fallot.

Consideration of the Pathological Features of Pediatric Congenital Heart Diseases Which Are Ideally Suitable for Diagnosing With Multidetector-row CT

Background

A lots of articles published regarding the usefulness of multidetector-row computed tomography (MDCT) in children with congenital heart disease (CHD) mostly describe that it can be an alternative to the invasive catheterization and angiography. The unique diagnostic features of this imaging modality have been largely ignored or disregarded. We described the pathological conditions that cannot be diagnosed by conventional angiography with cardiac catheterization but can be accurately diagnosed by MDCT.

Methods

We retrospectively reviewed non-ECG-gated MDCT images acquired from 452 children and young adults with CHD between 2005 and 2010 in our institute. In this article, we focused on the diagnostic advantages of MDCT, and indicated five pathological conditions. (1) When Blalock-Taussig shunt total occlusion prevents catheter insertion into the artificial vessel and angiography is ruled out, the peripheral pulmonary artery during the peripheral pulmonary artery can be imaged and diagnosed using MDCT based on blood flow supplied from many small collateral vessels originating from the aorta. (2) The location and protrusion of the device in the vessel after coil embolization to treat patent ductus arteriosus can be accurately visualized by virtual endoscopy using MDCT. (3) Calcification of patches, synthetic blood vessels, and other prostheses that is indistinct on conventional angiograms is clear on MDCT. (4) Simultaneous MDCT observations of the anatomical relationships between arterial and venous systems on the same image can clarify the detail diagnosis for surgical treatment. (5) Compression of the airways by the great vessels and pulmonary segmental emphysematous change can be diagnosed by MDCT.

Results and Conclusions

Among patients with CHD, MDCT is useful not only as a non-invasive alternative to conventional angiography, but also as a tool for specific morphological diagnoses. In the future, it will be necessary to accumulate experience in the recognition of cardiovascular conditions under which MDCT is necessary and to perform as the appropriate examination.

[Role of MSCT and MRI in the diagnosis of congenital heart disease]

Initial diagnosis of congenital heart disease traditionally relies upon clinical examination and ultrasound. Development of non-invasive imaging, multislice CT (MSCT) and magnetic resonance imaging (MRI) has changed the way those patients are evaluated for diagnosis or follow-up. Cardiac catheterization is no longer the step two and in many clinical situations, non-invasive imaging is the method of choice, either before or instead of invasive angiography examination. Cross-sectional cardiovascular imaging brings thorough examination of the thorax, heart and great vessels, leading to three-dimensional volumes imaging, allowing diagnosis of the cardiopathy, evaluation of the anatomy and associated abnormalities. For each imaging technique advantages and drawbacks are discussed. X-ray use is the main disadvantage of MSCT, although it is a fast, easy and efficient technique, especially in babies because of its high spatial and temporal resolutions. Beside a precise 3D evaluation of the heart and great vessels, MSCT allows evaluation of small structures, like coronary arteries in routine, including in neonates and infants, at a fast cardiac rhythm, and in a short examination time. The air-filled structures are well-depicted with MSCT, and 3D imaging is helpful in evaluation of tracheal and bronchi compression as compared to MRI. MR imaging brings, aside from the morphologic evaluation, helpful functional information for the left and right ventricles, and evaluation of valvular disease (stenosis and regurgitation). Those are critical data in the follow-up of patients treated for tetralogy of fallot or after atrial switch for transposition of the great vessels. The technique is also very powerful in evaluating aortic disease, e.g. aortic coarctation and restenosis, and Marfan's disease. Disadvantages are mainly the accessibility and the examination time, which in young patients may require sedation or general anaesthesia. Cross-sectional cardiovascular imaging, MSCT and MRI, have considerably changed the diagnosis and follow-up of patients suffering of congenital cardiopathy. The techniques are complementary, and the choice will depend on the age, the clinical condition and the diagnosis of the patient.

Radiation dose for thoracic and coronary step-and-shoot CT using a 128-slice dual-source machine in infants and small children with congenital heart disease

BACKGROUND

For coronary artery visualization, retrospective ECG-gated acquisition by dual-source computed tomography (DSCT) was superior to spiral non-ECG-gated acquisition in a paediatric population of congenital heart disease (CHD) patients. However, retrospective cardiac CT is associated with substantial radiation doses to the patient. Recently, DSCT with end-systolic reconstruction was found to be robust for imaging the coronary arteries in patients with high heart rates.

OBJECTIVE

To evaluate step-and-shoot DSCT with end-systolic reconstruction for evaluating the heart, coronary arteries and other thoracic structures in young children with CHD.

MATERIALS AND METHODS

All neonates and children younger than 6 years of age who were referred to our institution for CHD evaluation between September and October 2009 were included in the study. ECG-gated DSCT was performed in sequential prospective mode centred on the systolic phase identified by ECG analysis. To assess the radiation dose, we recorded the dose-length product (DLP) in mGy·cm and the effective dose in mSv estimated from the DLP. Overall image quality was evaluated using a 5-grade scoring system and was assessed by looking at cardiac and vascular structures. The image quality for the proximal and middle segments of the right and left coronary arteries was also evaluated using a 5-grade scale.

RESULTS

Images of diagnostic quality (grade ≥ 3) were obtained in all 30 children with a mean image quality grade of 4.7 ± 0.6 (range, 3-5). Mean DLP was 5.7 ± 4.8 mGy*cm (range, 1-22 mGy cm) and mean effective radiation dose was 0.26 ± 0.16 mSv (range, 0.05-0.8 mSv).

CONCLUSION

Prospective ECG-gated thoracic DSCT at end-systole usually provides adequate thoracic and coronary artery image quality in neonates, infants and young children with CHD, independent of heart rate. This new method is associated with lower radiation doses compared to previous literature (mean effective dose, 0.26 mSv).

Multislice computed tomography is useful for evaluating partial anomalous pulmonary venous connection

Volume-rendered images, derived from multidetector-row computed tomography (MDCT), can facilitate assessment of the morphology of partial anomalous pulmonary venous connection and are thus useful in pre-operative planning to prevent surgical morbidity and assist post-operative evaluations.

Multidetector computed tomography and 3-dimensional imaging: preoperative evaluation of thoracic vascular and tracheobronchial anomalies and abnormalities in pediatric patients

In the past decade, rapid technical developments and advancements of multidetector computed tomography (MDCT) have revolutionized the preoperative imaging evaluation of thoracic vascular and tracheobronchial anomalies and abnormalities in infants and children. Multidetector computed tomography enables noninvasive, rapid, high-resolution, and 3-dimensional (3D) imaging of the thorax in pediatric patients that provides comprehensive preoperative surgical guidance for pediatric surgeons. With the increasing availability of MDCT and 3D imaging, a practical review is needed for the pediatric surgeon of the evolving role of these techniques in the preoperative evaluation of surgical lesions in infants and children. This article focuses on the review of advantages and disadvantages of MDCT in comparison to other imaging modalities, 2D and 3D imaging postprocessing techniques, and MDCT and 3D imaging appearance of various thoracic vascular and tracheobronchial anomalies and abnormalities in pediatric patients. The primary aim of this article was to facilitate the pediatric surgeons' ability to successfully incorporate MDCT and 3D imaging as a routine preoperative imaging tool for the evaluation of thoracic surgical lesions in infants and children.

Uncorrected pink tetralogy of Fallot in an adult patient: incidental CT findings

Tetralogy of Fallot (TOF), one of the most common congenital heart diseases, has four major components: right ventricular hypertrophy, overriding aorta, membranous ventricular septal defect, and right ventricular outflow tract obstruction. If not already present at birth, cyanosis develops in the first year of life. Survival of the patient depends on the degree of pulmonary obstruction and the pulmonary blood supply. Patients rarely survive after the fourth decade of life. Limitation of blood to the lungs combined with ventricular septal defect results in supply of oxygen-poor blood to the body, causing cyanosis (blue coloration) in the patient. If the pulmonary stenosis is mild and ventricular septal defect is in balance, however, the noncyanotic patient is referred as having "pink tetralogy of Fallot."

Evaluation of image quality and radiation dose of thoracic and coronary dual-source CT in 110 infants with congenital heart disease

BACKGROUND

There are only a few reports on the diagnostic accuracy, and the technical and clinical feasibility, of multidetector CT (MDCT) in infants with congenital heart disease (CHD).

OBJECTIVE

To evaluate the image quality and radiation dose of DSCT in babies with CHD.

MATERIALS AND METHODS

From November 2006 to November 2007, 110 consecutive infants with CHD referred for pre- or postoperative CT evaluation were included. All these infants had a spiral angiothoracic DSCT scan after injection of 300 mg/ml iopromide at 0.5-1 ml/s with a power injector using a low-dose protocol (80 kVp and 10 mAs/kg). Of these infants, 34 also underwent an ECG-gated coronary CT scan for evaluation of the course of the coronary arteries.

RESULTS

No serious adverse events were recorded. The mean dose-length product was 8+/-6 mGy x cm (effective dose 0.5+/-0.2 mSv) and 21+/-9 mGy x cm (effective dose 1.3+/-0.6 mSv) during the non-ECG-gated spiral acquisition and ECG-gated acquisition, respectively. Diagnostic quality images were achieved with the spiral acquisition in 89% of cases. Compared to the spiral mode, ECG-gated acquisition significantly improved the visualization of the coronary arteries, with a diagnostic rate of 91% and 84% for the left and right coronary arteries, respectively.

CONCLUSION

DSCT together with iopromide at 300 mg/ml is a valuable tool for the routine clinical evaluation of infants with CHD. ECG-gated acquisition provides reliable visualization of the course of the coronary arteries.

Isolation of the left subclavian artery-origin from the left pulmonary artery by way of ductus arteriosus: multidetector row computed tomographic angiographic imaging

Right aortic arch with isolation of the left subclavian artery is a rare anomaly. It has been reported to occur with conotruncal anomalies and may be associated with 22q11 deletion. Multidetector-row computed tomographic angiogram images of a 15-year-old African boy with Tetralogy of Fallot who had right aortic arch and isolated left subclavian artery arising from the left pulmonary artery by way of ductus arteriosus are presented.