3D echocardiography in congenital heart disease: a valuable tool for the surgeon

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.

3D Approaches in Complex CHD: Where Are We? Funny Printing and Beautiful Images, or a Useful Tool?

Echocardiography, CT and MRI have a crucial role in the management of congenital heart disease (CHD) patients. All of these modalities can be presented in a 2D or a 3D rendered format. The aim of this paper is to review the key advantages and potential limitations, as well as the future challenges of a 3D approach in each imaging modality. The focus of this review is on anatomic rather than functional assessment. Conventional 2D echocardiography presents limitations when imaging complex lesions, whereas 3D imaging depicts the anatomy in all dimensions. CT and MRI can visualise extracardiac vasculature and guide complex biventricular repair. Three-dimensional printed models can be used in depicting complex intracardiac relationships and defining the surgical strategy in specific lesions. Extended reality imaging retained dynamic cardiac motion holds great potential for planning surgical and catheter procedures. Overall, the use of 3D imaging has resulted in a better understanding of anatomy, with a direct impact on the surgical and catheter approach, particularly in more complex cases.

Intermodality agreement between TTE and low kVp ECG-gated MDCTA in diagnosis of complex CHD in pediatrics

Background

Transthoracic echocardiography (TTE) is considered the primary diagnostic modality in congenital heart disease (CHD). However, it has limited role in evaluation of extra-cardiac major vessels abnormalities. Cardiac catheterization angiography is considered the gold standard investigation, yet, it is invasive. The aim of this study is to evaluate the agreement between TTE and low kVp ECG-gated cardiac multi-detector CT angiography (MDCTA) in detecting cardiac and extra-cardiac findings of complex congenital heart disease in a sample size of 36 patients (19 males and 17 females) with an age ranged between 30 days and 12 years (mean age 25.5 months). All cases were diagnosed to have complex CHD clinically and by TTE then referred to undergo cardiac low kVp ECG-gated MDCTA to confirm diagnosis and for better assessment of extra-cardiac major vessels abnormalities. Data derived from both modalities were then compared to calculate the inter-technique variability by using Cohen’s kappa statistics.

Results

TTE diagnosed 96% of intra-cardiac anomalies and only 54% of extra-cardiac major vessels anomalies detected by MDCTA, with variable degrees of intermodality agreement in detection different anomalies ranging between perfect agreement in diagnosing most of intra-cardiac lesions and very poor agreement in diagnosing extra-cardiac SVC anomalies.

Conclusion

Low kVp ECG-gated cardiac MDCTA is a rapid, non-invasive and reliable diagnostic modality in complex congenital heart diseases. It confirms TTE findings in intra-cardiac anomalies and significantly surpasses TTE reliability in diagnosis of extra-cardiac major vessels anomalies. So, it is indispensable as part of adequate preoperative assessment algorithm in cases of complex CHD and can't be replaced by TTE even with the later providing accurate assessment of intra-cardiac anomalies.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Three-dimensional echocardiography in congenital heart disease

Three-dimensional echocardiography is a valuable tool for the assessment of cardiac function where it permits calculation of chamber volume and function. The anatomy of valvar and septal structures can be presented in unique and intuitive ways to enhance surgical planning. Guidance of interventional procedures using the technique has now become established in many clinical settings. Enhancements of image processing to include intracavity flow, image fusion and true 3D displays look set to further improve the contribution of this modality to care of the patient with congenital heart disease.

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.