Measurements of Coronary Artery Aneurysms Due to Kawasaki Disease by Dual-Source Computed Tomography (DSCT)

Diameters of coronary artery aneurysms (CAAs) complicating acute phase KD can strongly predict the long-term prognosis of coronary artery lesions (CAL). Recently, computed tomographic angiography (CTA) has been used to detect CAL, and the purpose of this study was to determine whether coronary artery diameters measurements by CTA using dual-source computed tomography (DSCT) can be used instead of coronary angiogram (CAG) measurements. Twenty-five patients (22 males and three females) with CAL due to KD, who had undergone both CTA and CAG within one year, were retrospectively evaluated between 2007 and 2013. A prospective electrocardiogram-triggered CTA was performed on a DSCT (SOMATOM^® Definition, Siemens Healthcare, Germany). Two pediatric cardiologists independently measured the diameters of CAAs twice in each maximum intensity projection (MIP), curved multiplaner reconstruction (MPR) and CAG. We measured 161 segments in total (segment 1–3, 5–7, 11, 13). Diagnostic accuracy was expressed as κ coefficient. A Bland–Altman analysis was also used to assess the intra-observer, inter-observer and inter-modality agreement. The diagnostic quality of CTA was excellent (κ = 0.93). Excellent inter-observer agreement for the diameters of CAAs was obtained for MIP, MPR and CAG and for the intra-observer agreement. The inter-modality agreement was also excellent in measurements of CAA (MPR–CAG: y = 0.9x + 0.40, r = 0.97, p < 0.0001 MIP–CAG: y = x + 0.1, r = 0.94, p < 0.0001). These values in normal coronary arteries were also obtained. We found a significant correlation between CTA and CAG in measuring the coronary arteries. We conclude that measuring coronary artery diameters by CTA is reliable and useful.     

Evaluation of image quality and radiation dose at prospective ECG-triggered axial 256-slice multi-detector CT in infants with congenital heart disease

Background

There are a limited number of reports on the technical and clinical feasibility of prospective electrocardiogram (ECG)-gated multi-detector computed tomography (MDCT) in infants with congenital heart disease (CHD).

Objective

To evaluate image quality and radiation dose at weight-based low-dose prospectively gated 256-slice MDCT angiography in infants with CHD.

Materials and methods

From November 2009 to February 2010, 64 consecutive infants with CHD referred for pre-operative or post-operative CT were included. All were scanned on a 256-slice MDCT system utilizing a low-dose protocol (80?kVp and 60?C120?mAs depending on weight: 60?mAs for ??3?kg, 80?mAs for 3.1?C6?kg, 100?mAs for 6.1?C10?kg, 120?mAs for 10.1?C15?kg).

Results

No serious adverse events were recorded. A total of 174 cardiac deformities, confirmed by surgery or heart catheterization, were studied. The sensitivity of MDCT for cardiac deformities was 97.1%; specificity, 99.4%; accuracy, 95.9%. The mean heart rate during scan was 136.7?±?14.9/min (range, 91?C160) with a corresponding heart rate variability of 2.8?±?2.2/min (range, 0?C8). Mean scan length was 115.3?±?11.7?mm (range, 93.6?C143.3). Mean volume CT dose index, mean dose-length product and effective dose were 2.1?±?0.4?mGy (range, 1.5?C2.8), 24.7?±?5.9?mGy·cm (range, 14.7?C35.8) and 1.6?±?0.3?mSv (range, 1.1?C2.5), respectively. Diagnostic-quality images were achieved in all cases. Satisfactory diagnostic quality for visualization of all/proximal/distal coronary artery segments was achieved in 88.4/98.8/80.0% of the scans.

Conclusion

Low-dose prospectively gated axial 256-slice CT angiography is a valuable tool in the routine clinical evaluation of infants with CHD, providing a comprehensive three-dimensional evaluation of the cardiac anatomy, including the coronary arteries.     

Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT

The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (<1 years old) with CHD undergoing 128-slice CT prospective ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99 %), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75 %, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDI_vol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode.     

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.cm (effective dose 0.5±0.2 mSv) and 21±9 mGy.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.     

Visibility of the origin and proximal course of coronary arteries on non-ECG-gated heart CT in patients with congenital heart disease

Background: There is little information on the ability of non-ECG-gated cardiac CT to demonstrate the coronary arteries of children. Objective: To evaluate the visibility of the origin and proximal course of coronary arteries on non-ECG-gated cardiac CT, in which the coronary artery was not of primary diagnostic concern, in children with congenital heart disease. Materials and methods: From December 2002 to March 2004, 126 cardiac CT examinations from 104 children (median age 11 months; age range 1 day to 15 years) were evaluated. All patients had ventriculo-arterial concordance and no malformations of the great arteries; those with coronary artery anomalies were excluded. Contrast-enhanced 16-slice spiral CT was performed without ECG-gating and multiplanar images for coronary arteries were obtained. The visibility of coronary artery origins was graded on a three-point scale, while nine segments of the arteries were graded on a four-point scale. CT images in which it was possible to trace the coronary arteries were considered diagnostic. The visibility of each whole coronary artery and the origins and proximal four segments of coronary arteries were calculated. The visibility of coronary arteries was also correlated with patient age. Results: The percentage of CT images of diagnostic quality was 49.3% for the whole coronary artery and 81.7% for the origins and proximal four segments. There was a significant positive correlation between the visibility of coronary arteries and age. Conclusions: Non-ECG-gated cardiac CT, in which the coronary artery is not of primary diagnostic concern, is frequently able to visualize the origin and proximal course of coronary arteries and may be helpful in detecting coronary artery anomalies in children with congenital heart disease.     

Non-enhanced ECG-gated respiratory-triggered 3-D steady-state free-precession MR angiography with slab-selective inversion: initial experience in visualisation of renal arteries in free-breathing children without renal artery abnormality

Background

ECG-gated non-enhanced balanced steady-state free precession (bSSFP) MR angiography requires neither breath-holding nor administration of contrast material.

Objective

To investigate the image quality of free-breathing ECG-gated non-enhanced bSSFP MR angiography of renal arteries in children.

Materials and methods

Fourteen boys and seven girls (mean age, 9.7?years; range, 7?weeks–17?years) with no history of renovascular disease were included. MRI was performed at 1.5?T. Subjective image quality of axial and coronal maximum-intensity-projection reconstructions of four segments (I, aorta and renal artery ostium; II, main renal artery; III, segmental branches; IV, intrarenal vessels) was evaluated using a 4-point scale (4?=?excellent, 3?=?good, 2?=?acceptable, 1?=?non-diagnostic).

Results

Image quality was excellent for segments I (mean ± SD, 3.9?±?0.3) and II (4.0?±?0.1), good for segment III (3.4?±?0.9) and acceptable for segment IV (2.3?±?1.1 ). Mean image quality did not differ between sedated and non-sedated children.

Conclusion

bSSFP MR angiography enables visualisation of renal arteries in children.     

Safety and efficacy of a drug regimen to control heart rate during 64-slice ECG-gated coronary CTA in children

Background

The adult practice for ECG-gated single-source 64-slice coronary CTA (CCTA) includes administering beta-blockers to reduce heart rate. There are limited data on this process in children.

Objective

To evaluate the safety and efficacy of a drug regimen to decrease heart rate before performing CCTA in children.

Materials & methods

IV remifentanil and esmolol infusion were chosen to decrease heart rate in 41 children (mean age 6.5 years) while they were under general anesthesia (GA) for CCTA. Drug doses, changes in heart rate and procedural complications were recorded. CCTA image quality was graded on a scale of 1 to 5. The relationships between image quality and heart rate and image quality and age were evaluated. Patient effective radiation doses were calculated.

Results

Heart rates were lowered utilizing esmolol (4 children), remifentanil (2 children) or both (35 children); 26 children received nitroglycerin for coronary vasodilation. The mean decrease in heart rate was 26%. There were no major complications. The average image-quality score was 4.4. Higher heart rates were associated with worse image quality (r?=?0.67, P?<?0.0001). Older age was associated with better image quality (r?=?0.66, P?<?0.0001). Effective radiation doses were 0.7 to 7.0 mSv.

Conclusion

Heart rate reduction for pediatric CCTA can be safely and effectively achieved while yielding high-quality images.     

Single Coronary Artery Anomaly: Classification and Evaluation Using Multidetector Computed Tomography and Magnetic Resonance Angiography

The aim of this study was to use multidetector computed tomography (MDCT) and magnetic resonance (MRA) angiography to illustrate the classification and clinical characteristics of single coronary artery anomaly (SCAA). Retrospective evaluation of 22 adult and pediatric patients with SCAA by way of a medical archiving system was performed between June 2001 and August 2012. Imaging modalities used for coronary artery evaluation included MRA and MDCT angiography. Of the 22 patients, the majority (n = 8; 36 %) showed an interarterial course, the subtype having the worst prognosis. The retroaortic course (n = 3; 14 %) and course anterior to the pulmonary trunk (n = 3; 14 %) were the next most frequent patterns. Additional types (n = 8; 36 %) included the following: L-I, R-III, septal, and combined. Four patients (18 %) showed atherosclerotic involvement. SCAA anomaly was diagnosed as an incidental finding in the majority of patients evaluated initially for cardiovascular diseases (n = 19; 86 %). Two patients (9 %) required surgical interventions solely for their anomaly. Nine patients (41 %) were found to have coexisting congenital heart disease. Although conventional catheter angiography is responsible for the current classification of SCAA, advanced imaging modalities are useful in the evaluation of morphological and clinical characteristics of single coronary arteries.     

Comparison Between Proximal Thoracic Vascular Measurements Obtained by Contrast-Enhanced Magnetic Resonance Angiography and by Transthoracic Echocardiography in Infants and Children With Congenital Heart Disease

Accurate assessment of the proximal thoracic vasculature in infants and children with congenital heart disease (CHD) is vital for deciding the appropriate surgical or interventional procedure and predicting outcomes. This information usually is obtained by transthoracic echocardiography (TTE). Contrast-enhanced magnetic resonance angiography (CE-MRA) frequently is used to obtain diagnostic data when the image quality by TTE is limited. Calculation of z-scores for measurements obtained by CE-MRA in this population currently is not possible due to the lack of normative data. A reasonable agreement between vessel dimensions by CE-MRA and TTE will allow the use of TTE-based z-scores on measurements from CE-MRA. This study examines the accuracy and agreement of proximal thoracic vascular measurements obtained by CE-MRA versus TTE. Infants and children younger than 3 years with CHD who had a CE-MRA between August 2006 and May 2011 were retrospectively identified. Main and branch pulmonary arteries, ascending aorta, distal transverse arch, and aortic isthmus were measured from CE-MRA and TTE in analogous imaging planes and locations by two investigators blinded to each other. The study enrolled 35 subjects with CHD. The median age was 129 days (range, 0–1077 days), and the median weight was 5.8 kg (range, 2.16–17 kg). The median interval between the two imaging methods was 9 days (range, 0–60 days). Data analysis was performed with 129 of the 210 possible paired measurements. The remaining 81 paired measurements could not be performed due to inaccurate visualization of vessel borders or an unavailable imaging plane from TTE, CE-MRA, or both. The range of vessel sizes measured from 2.8 to 23.4 mm. There was excellent correlation between CE-MRA and TTE (r = 0.94, p < 0.001). The mean difference between the measurements was –0.1 ± 1.2 mm, and the limits of agreement were ?2.5 to 2.3 mm. Proximal thoracic vascular measurements obtained by CE-MRA and TTE in infants and children with CHD have a strong correlation. The agreement between these two imaging methods is adequate. Until normative data for vessel size measurements obtained from CE-MRA are available for this population, TTE-based z-scores can be applied to the measurements obtained by CE-MRA.     

Prevalence and Predictors of Decreased Glomerular Filtration Rate in Tibetan Children with Congenital Heart Disease

Objectives

To assess the prevalence of decreased glomerular filtration rate (GFR) in Tibetan children with congenital heart disease (CHD) and its associated risk factors.

Methods

A total of 207 Tibetan children attending authors’ center for treatment of CHD from May 2012 through November 2012, were included in the study. GFR was estimated with the Schwartz formula (eGFR).

Results

The mean eGFR was 104.3?±?16.6 mL/min/1.73 m², and decreased in 21 children (10.1 %). In the cyanotic category, eGFR was decreased only in severely cyanotic individuals. In the acyanotic category with left ventricular overload, children with decreased eGFR were younger, more commonly lived in areas above 4,700 m, and had higher left ventricular internal dimensions indexed by body surface areas (LVID/BSA) (53.8?±?6.9 vs. 40.1?±?6.8 mm/m², P?P?P?2 (sensitivity: 75.0 %, specificity: 93.9 %). In the remaining category, decreased eGFR was only observed in those living above 4,700 m.

Conclusions

One tenth of Tibetan children with CHD had decreased eGFR. The risk factors included severe cyanosis, younger age, living above 4,700 m and higher LVID/BSA.     

Low-Dose Coronary Artery Computed Tomography Angiogram of an Infant with Tetralogy of Fallot Using a 256-Slice Multidetector Computed Tomography Scanner

The reported incidence of anomalous coronary arteries among children is 0.17%, but it is much greater (8%) among children with tetralogy of Fallot (TOF). The diagnosis of coronary artery anomalies can be difficult using invasive aortography and is not without risk. Technical improvements with multidetector computed tomography (MDCT), including a reduced effective radiation dose, make cardiac CT angiography an attractive alternative not only because the risks of an invasive examination are avoided, but also because sedation risks also are eliminated in most cases. This report highlights 256-slice MDCT imaging of the coronary arteries in a nonsedated 26-day-old infant using an effective radiation dose of only 0.51 millisieverts (mSV).     

Visualization of neonatal coronary arteries on multidetector row CT: ECG-gated versus non-ECG-gated technique

Background Multidetector CT (MDCT) seems to be a promising tool for detection of neonatal coronary arteries, but whether the ECG-gated or non-ECG-gated technique should be used has not been established. Objective To compare the detection rate and image quality of neonatal coronary arteries on MDCT using ECG-gated and non-ECG-gated techniques. Materials and methods Twelve neonates with complex congenital heart disease were included. The CT scan was acquired using an ECG-gated technique, and the most quiescent phase of the RR interval was selected to represent the ECG-gated images. The raw data were then reconstructed without the ECG signal to obtain non-ECG-gated images. The detection rate and image quality of nine coronary artery segments in the two sets of images were then compared. A two-tailed paired t test was used with P values <0.05 considered as statistically significant. Results In all coronary segments the ECG-gated technique had a better detection rate and produced images of better quality. The difference between the two techniques ranged from 25% in the left main coronary artery to 100% in the distal right coronary artery. Conclusion For neonates referred for MDCT, if evaluation of coronary artery anatomy is important for the clinical management or surgical planning, the ECG-gated technique should be used because it can reliably detect the coronary arteries. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

Multidetector CT for congenital heart patients: what a paediatric radiologist should know

Multidetector CT (MDCT) is increasingly used for imaging congenital heart disease (CHD) patients in addition to echocardiography, due to its ability to provide high quality three-dimensional images, giving a comprehensive evaluation of complex heart malformations. Using 4-slice or 16-slice CT, diagnostic information in CHD patients is limited to extra-cardiac anatomy, mainly the pulmonary arteries, aorta and venous connections. Due to high heart rates in babies however, coronary evaluation and intra-cardiac analysis were not reliable with the first generations of MDCT. Larger detector size with 64-slice CT and faster acquisition time, up to 75 ms for one slice, has progressively improved coronary and intra-cardiac visualization. Because radiation dose is the main concern, especially in children, every attempt to minimize dose whilst preserving image quality is important: the ALARA concept should always be applied in this population. The 80 kVp setting is now well accepted as a standard for more and more radiological teams involved in CT of children. Different acquisition strategies are now possible for childhood coronary imaging, using retrospective or even prospective gating. Using the latest technology, sub-mSv acquisitions are now attainable for scanning a whole thorax, providing a complete analysis of any 3-D cardiac malformation, including coronary artery course visualisation. This review will describe how technological developments have improved image quality with continuous reduction of radiation dose.     

Tube current reduction in pediatric non-ECG-gated heart CT by combined tube current modulation

Background Dose reduction by combined tube current modulation has not been evaluated in pediatric low-dose CT. Objective This study was performed to evaluate tube current reduction in non-ECG-gated heart CT angiography in children by combined tube current modulation, and to assess the effects of body weight, age, sex, and scan direction on tube current reduction. Materials and methods From September 2004 to January 2005, non-ECG-gated heart CT examinations were performed with combined tube current modulation in 50 children (median age 1 year, range 1 month to 16 years; M/F 29/21) with congenital heart disease. Sixteen-slice spiral CT studies were obtained using a weight-based low-dose protocol (80 kVp, 50–160 effective mA). CT scans were obtained in the craniocaudal direction when leg veins (n=36) were used for IV injection of contrast agent and in the caudocranial direction when arm veins (n=13) were used. In one child who underwent a Fontan operation, both arm and leg veins were used. We calculated tube current reduction by combined tube current modulation and evaluated the effects of body weight, age, sex, and scan technique on tube current reduction. The quality of CT angiography images was visually evaluated by an experienced pediatric radiologist. Results Overall tube current reduction by combined tube current modulation was 15.8±11.1%. The reduction was variable among five body weight groups (9.3±7.9% for <4.9 kg, 14.3±9.3% for 5.0–9.9 kg, 16.4±12.5% for 10.0–19.9 kg, 25.8±9.8% for 20.0–39.9 kg, 15.9±12.7% for 40.0–59.9 kg) and was significantly different among the five groups (P=0.017). When eight children in the 40.0–59.9-kg group were excluded, age showed a significant positive correlation with tube current reduction (γ=0.4, P=0.003). There was no significant difference in tube current reduction between boys and girls. Tube current reduction was significantly greater for the caudocranial scan (21.2±9.2%) than for the craniocaudal scan (14.2±11.3%) (P=0.049). All CT angiography images were of diagnostic quality. Conclusions Combined tube current modulation reduced tube current in pediatric non-ECG-gated heart CT by 15.8% without degradation of image quality. With our CT protocol, for body weights up to 39.9 kg, age showed a significant positive correlation with tube current reduction, but there was a lower dose-saving effect in children heavier than 40 kg. Tube current reduction was not affected by sex, but was affected by scan direction. An erratum to this article can be found at     

Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation

Background

Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis.

Objective

To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard.

Materials and methods

The study group comprised 12 patients (age 17.6?±?2.9?years, mean±SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6?±?13.5?months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA.

Results

Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56?±?0.95?mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n?=?32), stenoses (n?=?3) and occlusions (n?=?9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention.

Conclusion

Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures.     

Utility of Free-Breathing, Whole-Heart, Three-Dimensional Magnetic Resonance Imaging in the Assessment of Coronary Anatomy for Congenital Heart Disease

The incidence of coronary anomalies is increased in congenital heart disease (CHD). Whole-heart magnetic resonance imaging (MRI) has been proposed as a robust approach to coronary artery imaging without ionizing radiation. The proximal coronary arteries were imaged in 112 CHD patients (63 males) age 17 ± 13 years (range 11 days-68 years) using a navigator-gated, whole-heart, three-dimensional (3D) technique at 1.5 T. Two observers assessed image quality overall and for left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX), and right coronary artery (RCA) using a 5-point scale ranging from 0 (not visible) to 4 (clear margins). Weighted kappa was used to assess interobserver agreement. Coronary artery origins were visible in 99% of the patients. The left main origin was not visualized in one patient, although the LAD, LCX, and RCA were visualized. Eight patients (7%) had anomalies. The overall image quality was 3.3 ± 0.8 for reader 1 and 3.1 ± 1.0 for reader 2. Age had a significant effect on image quality, with younger patients having lower scores. Agreement between readers was moderate (overall kappa, 0.60). Free-breathing, navigator-gated, whole-heart 3D MRI is a useful, robust, and reliable noninvasive technique for assessing coronary artery origins and their proximal course with diagnostic quality in CHD patients.     

Body Mass Index (BMI) is Associated with the Therapeutic Response to Oral Rehydration Solution in Children with Postural Tachycardia Syndrome

We aimed to explore whether the body mass index (BMI) was associated with the therapeutic response to oral rehydration solution (ORS) in children with postural tachycardia syndrome (POTS). Fifty-four children diagnosed as having POTS were included in this study. Fifty-six healthy children served as the controls. Children with POTS were treated with ORS, and their treatment response was evaluated. The baseline BMI was obtained by measuring the height and weight. The Pearson correlation was made between the baseline BMI and change in heart rate from supine to upright (ΔHR) and between baseline BMI and symptom score change (post-treatment vs. pre-treatment) in the POTS group. The value of BMI in predicting the therapeutic response to ORS was assessed by analyses of the receiver operating characteristic (ROC) curve. The BMI in the POTS group was significantly lower than that in the control group (18.22 ± 3.23 vs. 20.62 ± 3.05 kg/m², p < 0.01). There were no statistical differences between responders and non-responders in symptom scores before treatment (p > 0.05), but symptom score was lower in responders than that in non-responders (1.52 ± 0.95 vs. 2.32 ± 1.22, p < 0.01) after treatment. The BMI in responders to ORS was significantly lower than that of non-responders (16.32 ± 2.28 vs. 20.43 ± 2.74 kg/m², p < 0.01). The BMI was correlated negatively with ΔHR in the POTS group (n = 54, r = ?0.766, p < 0.01) and with the decrease in symptom scores after treatment in POTS patients (n = 54, r = ?0.28, p < 0.05). ROC curve revealed the area under the curve to be 92.3 % (95 % confidence interval 0.829–0.996). A cutoff value of the BMI of 18.02 kg/m² had high sensitivity (92 %) and high specificity (82.8 %) for predicting the effect of ORS treatment for POTS. BMI is associated with the therapeutic response to ORS in children with POTS.     

Congenital Anomalies of Coronary Arteries in Children: The Evaluation of 22 Patients

Although congenital coronary artery anomalies are seen in 0.6–1 % of adult patients undergoing coronary angiography, the data for the pediatric population are few. This study of 22 children with coronary artery anomalies evaluated them in terms of demographic and clinical features and analyzed their angiographic findings and surgical results. Databases in the Department of Pediatric Cardiology at the University of Uludag were searched for all the patients with a diagnosis of congenital coronary artery anomaly who underwent coronary angiography between 1993 and 2013. Patients with coexistent congenital heart disease were excluded from the study. The study noted 22 patients (0.9 %; 10 boys and 11 girls) with coronary artery anomalies. The mean age of these patients was 58.77 ± 52.04 months (range, 1 month–16 years). Coronary arteriovenous fistula (50 %) and anomalous left coronary artery from the pulmonary artery (ALCAPA) (36 %) were the most common anomalies. In addition, the study included one patient with diffuse coronary artery hypoplasia, one patient with muscular bridge, and one patient with left main coronary artery originating from the right aortic sinus valsalva. Of the 11 patients who had coronary atrioventricular fistula, 7 were asymptomatic, whereas 75 % of the patients with ALCAPA syndrome were admitted because of heart failure. Although 13 patients had an exact diagnosis by echocardiography, 50 % of the patients with ALCAPA syndrome had their diagnosis determined by catheter angiography performed because of severe mitral regurgitation or dilated cardiomyopathy. The mortality rate for all the patients was found to be 18.1 %. Eight patients with coronary arteriovenous fistula have been followed up without surgery to the present. In contrast, seven patients with ALCAPA syndrome have undergone surgery, and three have died. Two of these patients died during the postoperative period, and the remaining patient died suddenly during the preoperative period at home. Isolated congenital coronary artery anomalies are very rare in the pediatric population. Although most congenital coronary artery anomalies are clinically silent, they may be associated with severe symptoms in children. Recognition of potentially serious anomalies such as ALCAPA syndrome is mandatory so that early surgical treatment can be prescribed.     

Evaluation of the impact of organ-specific dose reduction on image quality in pediatric chest computed tomography

Background

Organ-specific dose reduction significantly reduces the radiation exposure of radiosensitive organs.

Objective

The purpose of this study was to assess the impact of a novel organ-specific dose reduction algorithm on image quality of pediatric chest CT.

Materials and methods

We included 28 children (mean age 10.9?±?4.8 years, range 3–18 years) who had contrast-enhanced chest CT on a 128-row scanner. CT was performed at 100 kV using automated tube current modulation and a novel organ-specific dose-reduction algorithm (XCare?; Siemens, Forchheim, Germany). Seven children had a previous chest CT performed on a 64-row scanner at 100 kV without organ-specific dose reduction. Subjective image quality was assessed using a five-point scale (1-not diagnostic; 5-excellent). Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were assessed in the descending aorta.

Results

Overall mean subjective image quality was 4.1?±?0.6. In the subgroup of the seven children examined both with and without organ-specific dose reduction, subjective image quality was comparable (score 4.4?±?0.5 with organ-specific dose reduction vs. 4.4?±?0.7 without it; P?>?0.05). There was no significant difference in mean signal-to-noise ratio and contrast-to-noise ratio with organ-specific dose reduction (38.3?±?10.1 and 28.5?±?8.7, respectively) and without the reduction (35.5?±?8.5 and 26.5?±?7.8, respectively) (P?>?0.05). Volume computed tomography dose index (CTDI_vol) and size-specific dose estimates did not differ significantly between acquisitions with the organ-specific dose reduction (1.7?±?0.8 mGy) and without the reduction (1.7?±?0.8 mGy) (P?>?0.05).

Conclusion

Organ-specific dose reduction does not have an impact on image quality of pediatric chest CT and can therefore be used in clinical practice to reduce radiation dose of radiosensitive organs such as breast and thyroid gland.     

Radiofrequency Catheter Ablation of Accessory Atrioventricular Pathways in Infants and Toddlers ≤ 15 kg

Accessory atrioventricular pathways (AP) are the most common substrate for paroxysmal supraventricular tachycardia in infants and small children. Up-to-date data on AP ablation in infants and small children are limited. The aim of the present study was to gain additional insight into radiofrequency (RF) catheter ablation of AP in infants and toddlers focusing on efficacy and safety in patients with a body weight of ≤ 15 kg. Since 10/2002, RF ablation of AP was performed in 281 children in our institution. Indications, procedural data as well as success and complication rates in children with a body weight ≤ 15 kg (n = 22) were compared with children > 15 kg (n = 259). Prevalence of structural heart anomalies was significantly higher among children ≤ 15 kg (27 vs. 5.7 %; p = 0.001). Procedure duration (median 262 vs. 177 min; p = 0.001) and fluoroscopy time (median 20.6 vs. 14.0 min; p = 0.007) were significantly longer among patients ≤ 15 kg. Procedural success rate did not differ significantly between the two groups (82 vs. 90 %). More RF lesions were required for AP ablation in the smaller patients (median 12 vs. 7; p = 0.019). Major complication rate was significantly higher in children ≤ 15 kg (9 vs. 1.1 %; p = 0.05) with femoral vessel occlusion being the only major adverse event in patients ≤ 15 kg. Catheter ablation of AP in children was effective irrespective of body weight. In children ≤ 15 kg, however, procedures were more challenging and time-consuming. Complication rate and number of RF lesions in smaller children were higher when compared to older children.