Cardiac Computed Tomography-Derived Left Atrial Strain and Volume in Pediatric Patients With Congenital Heart Disease: A Comparative Analysis With Transthoracic Echocardiography

Purpose

This study aimed at exploring the feasibility and reproducibility of CCT for the measurement of Left Atrial (LA) strain and volume compared with transthoracic echocardiography (TTE) in pediatric patients with congenital heart disease (CHD).

Materials and Methods

The present study included 43 postoperative patients with CHD (7.39 ± 3.64 years, 56% male) who underwent clinically indicated CCT, and all patients underwent additional TTE on the same day. LA strain and volume parameters were measured by dedicated software. The correlation and agreement of LA strain and volume parameters were assessed using Pearson’s correlation coefficient and Bland-Altman analysis. Intra-class correlation coefficients (ICC) were used to assess CCT intra-observer and inter-observer reproducibility.

Results

All strain parameters of CCT were lower compared to TTE (reservoir strain: 28.37 ± 6.92 vs. 32.15 ± 8.15, respectively; conduit strain: 21.33 ± 6.46 vs. 24.23 ± 7.75, respectively; booster strain: 7.04 ± 2.74 vs. 7.92 ± 3.56). While the volume parameters of CCT were higher compared to TTE (LAV: 29.60 ± 19.01 vs. 25.66 ± 17.60, respectively; LAVi: 30.36 ± 22.31 vs. 28.63 ± 19.25, respectively). Both LA strain and volume measurements showed good correlation and agreement between the two modalities (r = 0.63–0.87, p < 0.001). CT-derived LA strain and volume measurements showed good intra- and inter-observer reproducibility using prototype software (ICC = 0.78–0.96).

Conclusions

CCT was feasible for measuring LA strain and volume with good correlation and high reproducibility as compared with TTE. As a complementary modality, CCT can regard as an accepted method in the evaluation of LA function in pediatric patients with CHD

Postoperative evaluation of left ventricular global strain using cardiac computed tomography in pediatric patients with congenital heart disease: A comparison with echocardiography

PURPOSE

We explored the feasibility and reproducibility of cardiac computed tomography (CCT)-derived left ventricular (LV) global strain in postoperative children
with congenital heart disease (CHD) and compared its correlation and agreement with transthoracic echocardiography (TTE).

METHODS

Fifty-one patients (28 males, 23 females) were included who underwent clinically indicated retrospective electrocardiography-triggered CCT. and all patients underwent additional TTE on the same day. LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were measured. Correlations of global strains between CCT and TTE were assessed using Pearson's correlation coefficient. Intra-class correlation coefficients (ICC) were used to assess CCT intra-observer and inter-observer reproducibility.

RESULTS

GLS and GCS were not significantly different between CCT and TTE (GLS: -23.54 ± 3.24 vs. -23.85 ± 3.72, respectively, p = 0.415; GCS: -28.21 ± 3.55 vs. -28.79 ± 3.69, respectively, p = 0.155). GRS was significantly different between CCT and TTE (60.79 ± 15.11 vs. 41.73 ± 4.27, respectively, p < 0.001). There was good correlation between CCT- and TTE-derived GLS (r = 0.70, p < 0.001) and GCS (r = 0.68, p < 0.001), but GRS showed no correlation between CCT and TTE (r = 0.09, p = 0.54). CCT-derived global strain showed good intra- and inter-observer reproducibility (ICC = 0.86-0.92), except the inter-observer reproducibility for GRS (ICC = 0.77).

CONCLUSIONS

CCT was feasible for postoperative evaluation of LV global strain in pediatric patients with CHD with sufficient reproducibility. CCT-derived global strain can provide additional information in selected CHD patients with poor acoustic windows and who are intolerant to or have contraindications for cardiac magnetic resonance.

Diagnostic accuracy of multi-slice computed tomography in children with Abernethy malformation

Background

Abernethy malformation is a rare congenital abnormality. Imaging examination is an important method for the diagnosis. The purpose of this study was to demonstrate manifestations of multi-slice computed tomography (MSCT) in Abernethy malformation and its diagnostic accuracy.

Methods

Fourteen children with Abernethy malformation were admitted to our center in China between July 2011 and January 2018. All 14 patients (eight males and six females) received MSCT and digital subtraction angiography (DSA) while eight patients also received ultrasound. The patients’ age ranged from 1 to 14 (median age 8 years old). The clinical records of the patients were retrospectively reviewed. MSCT raw data were transferred to an Advantage Windows 4.2 or 4.6 workstation (General Electric Medical Systems, Waukesha, WI). We compared the findings of MSCT with DSA and surgical results in order to ascertain diagnostic accuracy.

Results

Three cases had type Ib Abernethy malformation and eleven cases had type II. Two cases of type II Abernethy malformation were misdiagnosed as type Ib using MSCT. Comparing the findings of MSCT with DSA and surgical results, the accuracy of MSCT was 85.7% (12/14), in which 100.0% (3/3) were type Ib and 81.8% (9/11) were type II. Clinical information included congenital heart disease, pulmonary hypertension, diffuse pulmonary arteriovenous fistula, abnormal liver function, hepatic nodules, elevated blood ammonia, and hepatic encephalopathy. Eleven cases were treated after diagnosis. One patient with Abernethy malformation type Ib (1/3) underwent liver transplantation. Seven patients with Abernethy malformation type II (7/11) were treated by shunt occlusion, received laparoscopy, or were treated with open surgical ligation. Another three patients (3/11) with Abernethy malformation type II were treated by interventional portocaval shunt occlusion under DSA.

Conclusion

MSCT attains excellent capability in diagnosing type II Abernethy malformation and further shows the location of the portocaval shunt. DSA can help when it is hard to determine diagnosis between Abernethy type Ib and II using MSCT.

Layer thickness dependence of the terahertz emission based on spin current in ferromagnetic heterostructures

The emission with a bandwidth of 1.5 terahertz based on the spin current in the ferromagnetic heterostructure Co/Pt is demonstrated. The spin transient launched by the NIR femtosecond laser pulse in the Co/Pt is converted into the in-plane charge current due to the inverse spin Hall effect, which gives rise to the terahertz emission towards free space. The dependence of the terahertz emission on the Pt-layer thickness is investigated. To optimize the geometry structure of the new type of emitter, we developed the theoretical model by carefully analyzing the spin transport. Our model reveals the importance to take into account the interfacial spin loss. It can be used to analyze more complex heterostructures.

A prospective evaluation of contrast and radiation dose and image quality in cardiac CT in children with complex congenital heart disease using low-concentration iodinated contrast agent and low tube voltage and current

OBJECTIVE

To the assess image quality, contrast dose and radiation dose in cardiac CT in children with congenital heart disease (CHD) using low-concentration iodinated contrast agent and low tube voltage and current in comparison with standard dose protocol.

METHODS

110 patients with CHD were randomized to 1 of the 2 scan protocols: Group A (n = 45) with 120 mA tube current and contrast agent of 270 mgI/ml in concentration (Visipaque^™; GE Healthcare Ireland, Co., Cork, UK); and Group B (n = 65) with the conventional 160 mA and 370 mgI/ml concentration contrast (Iopamiro^®; Shanghai Bracco Sine Pharmaceutical Corp Ltd, Shanghai, China). Both groups used 80 kVp tube voltage and were reconstructed with 70% adaptive statistical iterative reconstruction algorithm. The CT value and noise in aortic arch were measured and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. A five-point scale was used to subjectively evaluate image quality. Contrast and radiation dose were recorded.

RESULTS

There was no difference in age and weight between the two groups (all p > 0.05). The iodine load and radiation dose in Group A were statistically lower (3976 ± 747 mgI vs 5763 ± 1018 mgI in iodine load and 0.60 ± 0.08 mSv vs 0.77 ± 0.10 mSv in effective dose; p < 0.001). However, image noise, CT value, CNR, SNR and subjective image quality for the two groups were similar (all p > 0.05), and with good agreement between the two observers. Comparing the surgery results, the diagnostic accuracy for extracardiac and intracardiac defects for Group A was 96% and 92%, respectively, while the corresponding numbers for Group B were 95% and 93%.

CONCLUSION

Compared with the standard dose protocol, the use of low tube voltage (80 kVp), low tube current (120 mA) and low-concentration iodinated contrast agent (270 mgI/ml) enables a reduction of 30% in iodine load and 22% in radiation dose while maintaining compatible image quality and diagnostic accuracy. Advances in knowledge: The new cardiac CT scanning protocol can largely reduce the adverse effects of radiation and contrast media to children. Meanwhile, it also can be used effectively to examine complex CHD.

Multi-slice computed tomography assessment of bronchial compression with absent pulmonary valve

BACKGROUND

Absent pulmonary valve is a rare cardiovascular anomaly that can result in profound tracheobronchial compression.

OBJECTIVE

To demonstrate the advantage of multi-slice CT in diagnosing tracheobronchial compression, its severity as related to the adjacent dilated pulmonary arteries, and associated lung and cardiac lesions.

MATERIALS AND METHODS

We included children with absent pulmonary valve who were reviewed by multi-slice CT during a 17-year period. The number and locations of stenoses and lung lesions were noted and the severity of stenosis was categorized. The diameter of the pulmonary artery was measured and associated cardiac defects were demonstrated.

RESULTS

Thirty-one children (14 girls and 17 boys) were included. Of these, 29 had ventricular septal defect and 2 had an intact ventricular septum. Twenty-nine children (94%) had tracheobronchial compression, judged to be mild in nine children (31%), moderate in 10 (34%) and severe in 10 (34%). The different locations of the stenosis (carina, main bronchi, lobar and segmental bronchi) were observed. And the number and location of lung lesions demonstrated that the right middle and left upper and lower lobes were often affected. The diameter of the pulmonary artery in these children was well above normal published values, and Spearman rank correlation analysis showed a correlation between the size of the pulmonary artery and the severity of the tracheobronchial stenosis. Nineteen children (61%) underwent surgery and 4 of these children had a multi-slice CT post-operative follow-up study.

CONCLUSION

Absent pulmonary valve can cause significant morbidity and mortality in children. Multi-slice CT can accurately depict areas of tracheobronchial compression, associated lung lesions and cardiac defects, helping to direct the surgeon.