Angiography In Children Research Articles

Evaluation of Contrast Injection Site Effectiveness: Thoracic CT Angiography in Children With Hand Injection of IV Contrast Material

OBJECTIVE. The purpose of this study was to evaluate the effectiveness of various contrast injection sites when performing thoracic CT angiography (CTA) using hand injection of IV contrast material in infants and young children with a small IV catheter. MATERIALS AND METHODS. We used our hospital information system to retrospectively identify consecutive pediatric patients who underwent thoracic CTA with hand injection of contrast material from August 2012 to July 2013. The study indication for thoracic CTA was to evaluate the thoracic systemic arterial vasculature and pulmonary venous vasculature. Both qualitative and quantitative evaluation of thoracic CTA image quality was performed by two reviewers independently. Qualitative evaluation of thoracic CTA image quality was performed by visual assessment of the degree of contrast enhancement in the ROI on a 4-point scale. Quantitative evaluation was performed by measuring attenuation obtained with the ROI placed within the aorta at two locations (the level of the aortic arch and at the level of the carina) to evaluate the thoracic systemic arterial vasculature. For evaluation of the pulmonary venous system, attenuation measurements were obtained at the center of the left atrium. Six individual injection sites were identified: head, jugular vein, arm vein, hand vein, leg vein, and foot vein. Injection sites were categorized into three regional groups: head-neck region (head vein and jugular veins), upper extremity region (arm and hand veins), and lower extremity region (leg and foot veins). Comparisons of attenuation values between individual and regionally grouped contrast injection sites were determined using the F-test in ANOVA. RESULTS. The study cohort included 50 pediatric patients (29 boys and 21 girls; mean age, 8 months ± 1 year; range, 1 week to 5 years) who underwent a total of 50 thoracic CTA studies for evaluating the thoracic systemic arterial vasculature (n = 38; 76%) or pulmonary venous vasculature (n = 12; 34%). All 50 thoracic CTA studies were of diagnostic quality on the basis of qualitative evaluation (all ≥ 3). For quantitative evaluation with the threshold for a diagnostic thoracic CTA study defined as attenuation greater than 150 HU in the ROI, all 50 thoracic CTA studies were technically successful (aortic arch, 380 ± 150 HU; descending thoracic aorta at the level of the carina, 392 ± 155 HU; and left atrium, 352 ± 90 HU). There were no significant differences in mean attenuation between individual injection sites (p > 0.20 for each comparison) or different regional groups (p > 0.50 for each comparison). CONCLUSION. Diagnostic quality thoracic CTA can be achieved with hand injection of IV contrast material in infants and young children with a small IV catheter, independent of the IV access site.

Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrastenhanced cardiac computerized tomographic angiography in children.

Objective:The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases.Methods:Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in patients, which was followed by electrocardiogram gated cardiac CT angiography. General anesthesia was induced using sleep dose of intravenous propofol. After the initial check CT, on request by the radiologist, apnea was induced by the anesthesiologist by administering 1 mg/kg of intravenous suxamethonium. Soon after apnea ensued, the contrast was injected, and CT angiogram carried out. CT images in the “apnea group” were compared with those in “nonapnea group.” After the completion of the procedure, the patients were mask ventilated with 100% oxygen till the spontaneous ventilation was restored.Results:We studied 46 patients, of whom 36 with apnea and yet another 10 without. The quality of the image, visualization of structures such as cardiac wall, outflow tracts, lung field, aortopulmonary shunts, and coronary arteries were analyzed and subjected to statistical analysis (Mann–Whitney U, Fischer's exact test and Pearson's Chi-square test). In the induced apnea group, overall image quality was considered excellent in 89% (n = 33) of the studies, while in the “no apnea group,” only 30% of studies were excellent. Absent or minimal motion artifacts were seen in a majority of the studies in apnea group (94%). In the nonapnea group, the respiratory and body motion artifacts were severe in 50%, moderate in 30%, and minimal in 20%, but they were significantly lesser in the apnea group. All the studied parameters were statistically significant in the apnea group in contrast to nonapnea group (P < 0.000).Conclusion:The image quality of cardiac CT angiography greatly improves, and motion artifact significantly decreases with the use of induced apnea in pediatrics patients being evaluated for congenital heart disease. This technique poses no additional morbidity of significance.

Extracardiac applications of MR blood pool contrast agent in children.

Magnetic resonance (MR) angiography has significantly reduced the need for diagnostic conventional angiography and is preferred over CT angiography in children because of its lack of ionizing radiation. The availability of gadofosveset trisodium (the only clinically approved blood pool MR contrast agent) has led to an increase in applications of MR for vascular imaging and an improvement in diagnostic quality of MR angiography. Gadofosveset is a gadolinium-based contrast agent that binds reversibly to albumin, resulting in increased paramagnetic effect and longer intravascular residence. This allows for high-resolution arterial and venous MR angiography, assessment of flow characteristics of vascular malformations, dynamic vascular imaging, and multi-station imaging with a single low-dose gadolinium contrast injection. The purpose of this pictorial essay is to facilitate understanding of the kinetics and safety profile of gadofosveset trisodium, discuss technical aspects of imaging, and illustrate advantages and extracardiac applications in pediatric body imaging.

Effective radiation dosage of three-dimensional rotational angiography in children.

Three-dimensional rotational angiography (3DRA) is a relatively new but promising imaging technique in the paediatric catheterization laboratory. However, data on effective dose (ED) of this technique in children are lacking. The purpose of this study is to provide ED of 3DRA and to correlate this with parameters readily available in daily practice. Furthermore, the effect of dose-reducing techniques is evaluated. Effective doses were calculated with Monte Carlo PCXMC 2.0 in 14 patients who underwent a total of 17 3DRAs at our paediatric catheterization laboratory. Median age was 5.7 years (range 1 day-16.6 years). Median ED was 1.6 milliSievert (mSv) (range 0.7-4.9). Effective dose did not correlate with age and body surface area but did correlate with dose area product (DAP) and milliGray (mGy) with r(2) of 0.75 and 0.83, respectively. Reduction of the total amount of frames from 248 to 133 per rotation resulted in further dose reduction of over 50% with preserved image quality. The median ED of 3DRA in children is 1.6 mSv and correlates with DAP and mGy. This dose can be halved by applying frame reduction. A significant further dose reduction can be achieved by obtaining additional knowledge of the equipment used.

Assessment of coronary ischaemia by myocardial perfusion dipyridamole stress technetium-99 m tetrofosmin, single-photon emission computed tomography, and coronary angiography in children with Kawasaki disease: pre- and post-coronary bypass grafting.

Coronary artery lesions in Kawasaki disease invasively assessed by coronary angiography. Evaluation of myocardial perfusion by single-photon emission computed tomography may identify the haemodynamic significance of coronary lesions. To evaluate diagnostic accuracy of dipyridamole stress technetium-99 m tetrofosmin, single-photon emission computed tomography as a possible alternative to invasive coronary angiography for detection and follow-up of myocardial ischaemia in patients with Kawasaki disease, and pre- and post-coronary bypass grafting. Coronary angiography and single-photon emission computed tomography were performed on 21 patients who were classified into three groups - group I (stenosis), group II (giant aneurysms), and group III (small aneurysms). Of the 21 patients, 16 (groups I and II) patients with myocardial perfusion defects, who underwent coronary bypass grafting, were followed up with single-photon emission computed tomography. In group I, all patients had significant coronary stenosis and 100% of them had perfusion defects in the anterior and septal walls. In group II, all patients had giant aneurysms and 83% of them had inferior and inferolateral perfusion defects. In group III, all patients had small aneurysms and 100% of them had normal perfusion. Pre-coronary bypass grafting myocardial ischaemic defects disappeared in all patients after surgery. Sensitivity, specificity, and accuracy of single-photon emission computed tomography were 94, 100, and 95%, respectively. Technetium-99 m tetrofosmin single-photon emission computed tomography can be applied as an accurate non-invasive diagnostic technique for detecting myocardial perfusion defects with coronary artery lesions, and to show improved or even normalised perfusion of the myocardium in patients after surgical revascularisation.

Transient flow response after femoral artery catheterization for diagnostic neuroangiography in infants and children: Doppler US assessment of the ipsilateral femoral artery.

Hemodynamic changes in the distal arteries during transfemoral catheterization in children have not been documented. To evaluate arterial flow changes of the lower extremities ipsilateral to the puncture site using Doppler US during transfemoral cerebral angiography in children. Twenty-seven children who underwent transfemoral cerebral angiography at our institution between April 2013 and August 2013 compose our study population. Doppler US was performed to evaluate diameters and peak systolic velocities of the common femoral artery and superficial femoral artery before and after femoral sheath insertion. Children were classified into three groups based on the spectral waveform changes of the superficial femoral artery after femoral sheath insertion. Thereafter, one-way ANOVA followed by the Bonferroni post-hoc comparisons test were performed to compare values among the groups. Mean common femoral artery and superficial femoral artery baseline diameters were 4.10 mm and 3.32 mm, and mean baseline peak systolic velocities were 218.26 and 166.51 cm/s, respectively. Fourteen of 27 children showed persistent triphasic flow in the superficial femoral artery (group 1); 7 children showed altered flow of biphasic (n = 3) or monophasic (n = 4) waveforms (group 2); and 6 children showed pulsus tardus et parvus pattern (group 3) after femoral sheath insertion. Mean baseline diameter of the common femoral artery and mean subtracted value between common femoral artery and femoral sheath size were significantly smaller in group 3 than the other groups. Size discrepancy between common femoral artery and femoral sheath was <1 mm in all cases of group 3. Superficial femoral artery diameter and peak systolic velocity significantly decreased after femoral sheath insertion in group 3 compared to groups 1 and 2. A significant skin temperature drop after sheath insertion in the ipsilateral lower extremity was noted in group 3 (-1.83°C), compared to groups 1 and 2 (+0.42 and -0.86°C, respectively). Changes in the spectral waveforms of superficial femoral arteries frequently occur in children during transfemoral cerebral angiography (13/27, 48%). Significant arterial flow disturbance was noted on Doppler US in children with a common femoral artery <1 mm larger than the femoral sheath diameter.

Impact of Sinogram Affirmed Iterative Reconstruction (SAFIRE) Algorithm on Image Quality with 70 kVp-Tube-Voltage Dual-Source CT Angiography in Children with Congenital Heart Disease

PurposeTo compare the image quality and diagnostic accuracy between sinogram affirmed iterative reconstruction (SAFIRE) algorithm and filtered back projection (FBP) reconstruction algorithm at 70 kVp-tube-voltage DSCT angiography in children with congenital heart disease (CHD).Materials and MethodsTwenty-eight patients (mean age: 13 months; range: 2–48 months; male: 16; female: 12; mean weight: 8 kg) with CHD underwent 70 kVp DSCT angiography. Imaging data were reconstructed with both FBP and SAFIRE algorithms. Subjective image quality was evaluated on a five-point scale. The parameters of image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) on the objective image quality were compared for the two reconstruction algorithms. Surgery was performed in 20 patients, whereas conventional cardiac angiography (CCA) was performed in 8 patients. The diagnostic accuracy was evaluated on the surgical and/or CCA findings. The effective radiation doses were calculated.ResultsCompared to FBP algorithm, SAFIRE algorithm had significantly higher scores for subjective image quality (P<0.05), and lower image noise (P<0.05) as well as higher SNR &CNR values (P<0.05). There was no significant difference in the diagnostic accuracy between the FBP and SAFIRE algorithm (χ2 = 1.793, P>0.05). The mean effective dose for 70 kVp DSCT angiography was 0.30±0.13 mSv.ConclusionsThe SAFIRE algorithm can significantly reduce image noise and improve the image quality at 70 kVp DSCT angiography for the assessment of CHD in children.

Systemic Effects of Intracoronary Nitroglycerin during Coronary Angiography in Children after Heart Transplantation

Coronary spasm during coronary angiography for vasculopathy in children can be prevented by the intracoronary administration of nitroglycerin. We reviewed the anesthesia and catheterization reports and charts for pediatric transplant recipients who underwent angiography from 2005 through 2010. Correlation analysis was used to study the relation of post-injection systolic blood pressure (SBP) to nitroglycerin dose. Forty-one angiographic evaluations were performed on 25 patients (13 male and 12 female). Mean age was 9.9 ± 3.2 years (range, 3.3-16.1 yr). The mean total dose of nitroglycerin was 2.93 ± 1.60 µg/kg (range, 1-8 µg/kg). There was a significant drop between the baseline SBP (mean, 106 ± 21.6 mmHg) and the lowest mean SBP before nitroglycerin administration (78 ± 13.2, P <0.0001, paired t test). There was no significant additional change in SBP (mean after nitroglycerin administration, 80.7 ± 13.1 mmHg; P = 0.2). There was a significant drop in lowest heart rate between baseline (109 ± 16.5 beats/min) and before nitroglycerin administration (89 ± 14.3 beats/min; P <0.0001, paired t test). There was no significant additional change in heart rate (mean heart rate after nitroglycerin, 84 ± 17.7 beats/min; P = 0.09). There were 2 interventions for SBP before nitroglycerin and 2 after nitroglycerin. One child experienced a transient ST-T-segment change during angiography after nitroglycerin. In the highest dose range, the additional decrease in SBP was 7.2 mmHg (P=0.03). Routine intracoronary nitroglycerin administration in this dose range produced no significant changes in SBP or heart rate in children.

Complications of cerebral angiography in children younger than 3 years of age

The therapeutic potential for cerebral angiography (CA) in young children is expanding. However, its use in this patient population is limited by presumed higher complication rates among children. Therefore, to improve the accuracy of counseling of the parents/guardians of these patients and to identify modifiable risk factors, the authors evaluated complications after CA in young children. The authors reviewed data for 309 consecutive cerebral angiograms obtained in 87 children younger than 36 months of age from 2004 to 2010 at a single institution. They analyzed demographics, diagnosis, angiographic findings, and complications. The patient population comprised 40 boys and 47 girls; mean age was 14.36 months (range 1-36 months) and mean weight was 10.8 kg (range 3.7-21.0 kg). For 292 of the 309 procedures, intraarterial chemotherapy was administered; the remaining 17 procedures were for vascular malformations, stroke, tumor embolization, and intracranial hemorrhage. The rate of neurological complications was 0.0%. The rate of nonneurological complications was 2.9%: 7 cases of contrast allergy or bronchospasm, 1 groin hematoma (body weight 7 kg), and 1 transient femoral artery occlusion (body weight 10.8 kg). The rate of radiographic complications was 1.3%: 1 case of transient asymptomatic intraarterial dissection and 3 cases of asymptomatic vasospasm. Postprocedural MRI was performed for 33.3% of patients with no evidence of ischemia. There were no delayed complications. Mean follow-up time was 16.6 months. No association was found between complications and age, duration of anesthesia, number of vessels catheterized, size of the sheath, or diagnostic versus interventional procedures. Despite a trend toward a higher rate of complications for patients who weighed less than 15 kg, this finding was not significant (p = 0.35). The rate of complications for CA in young children is comparable to rates reported for older children and lower than rates reported for adults. When appropriately indicated, CA should not be omitted from the therapeutic strategy of children younger than 36 months of age.

Intraoperative cerebral angiography in arteriovenous malformation resection in children: a single institutional experience

The use of cerebral intraoperative angiography has been described in resection of arteriovenous malformations (AVMs) in adults. More recently, studies have described experiences with intraoperative angiography in a small number of children. However, data on the safety and clinical utility of intraoperative angiography in the pediatric population remains limited in comparison with available data in adults. The aim of the study was to evaluate the use of cerebral intraoperative angiography in children undergoing AVM resection. The clinical utility of intraoperative angiography and procedure-related complications were evaluated. A retrospective review was performed for all patients undergoing cerebral AVM resection with intraoperative angiography at The Children's Hospital of Philadelphia between 2008 and 2012. Patient imaging and operative and medical notes were reviewed to evaluate for end points of the study. A total of 17 patients (8 males, 9 females) were identified, with a median age of 12.1 years (range 1.2-17.9 years) and median weight of 45.5 kg (range 12.1-78.9 kg). A total of 21 intraoperative angiography procedures were performed for 18 AVM resections in 17 patients. The technical success rate was 94%. In 2 cases (11%), intraoperative angiography demonstrated a residual AVM, and repeat resections were performed. In both cases, no recurrent disease was noted on postoperative follow-up. One procedure-related complication (4.8%) occurred in 1 patient who was positioned prone. Recurrence to date was noted in 2 (14%) of the 14 cases with available postoperative follow-up at 3.5 and 4.7 months following resection with intraoperative angiography. The median follow-up time from intraoperative angiography to the most recent postoperative angiography was 1.1 years (range 4.3 months to 3.8 years). Intraoperative angiography is an effective and safe adjunct for surgical management of cerebral AVMs in the pediatric population.

Effective Radiation Dosages in 3D Rotational Angiography in Children

Background: Three-dimensional rotational angiography (3DRA) is a relatively new but promising imaging technique in the pediatric catheterization laboratory. However, data on the effective dose (E) of this technique are lacking, since they are very time consuming to obtain. The purpose of our study is to provide E of 3DRA and to correlate Ed to parameters readily available in daily practice.

Contrast enhanced magnetic resonance angiography in children: initial experience at 3.0 Tesla

Background To assess the role of contrast enhanced magnetic resonance angiography (CEMRA) at 3.0T in pediatric patients referred for vascular evaluation, and to compare the technical and diagnostic performance of a clinically similar control group at 1.5T. Methods Fifty pediatric patients referred for vascular evaluation and without evidence of congenital heart disease, were evaluated with CEMRA. Thirty-five patients received 37 studies at 3.0T (age 0.4 -16.5 years, mean 5.8 ± 4.7 years. Fifteen patients received 16 studies at 1.5T (age 0.1 - 17.5 years, mean 5.8 ± 6.4 years). CEMRA was performed in three phases: arterial, early venous and late venous. Two independent observers analyzed the studies for image quality, artifacts and vessel definition. Results Overall image quality and vessel definition scores were higher at 3.0T than 1.5T in the arterial and early venous phase, however not the late venous phase. Overall

Dual source multidetector computed tomography coronary angiography in the surgical planning regarding the major coronary artery anomalies in children

Background: This study aims to demonstrate major coronary artery anomalies such as anomalous origin and coronary artery fistulas on dual-source multi detector computed tomography (MDCT) coronary angiography in children before surgical treatment. Methods: Six children (3 boys, 3 girls; mean age 6 years; range 2 days to 15 years) referred for a MDCT coronary angiography for evaluation of coronary anomaly between January 2010 and June 2011 were included in this study. Electrocardiography (ECG)-gated dual-source MDCT coronary angiography was performed on all patients. No beta-blockers were given prior to the procedure. The mean heart rate was 98±20 bpm (range 128 to 75 bpm). In all patients, ostium, course, and end-distal portion of coronary artery were inspected for anomalies. Exact opening point was carefully assessed in patients with fistulas. Dual-source MDCT examination was performed with low kilovolt dose reduction algorithm (80 kV, range 150-350 mA) compatible with ALARA principles. Results: Three anomalous origin (one ALCAPA, two anomalous left main coronary artery originated from right sinus of Valsalva) and three fistulas (two coronary-cameral fistula, one left main coronary artery -coronary sinus fistula) were clearly identified with dual-source MDCT angiography. Conclusion: Dual source MDCT angiography is a noninvasive and effective method as an alternative to conventional coronary angiography for the preoperative assessment of major anomalous origin of coronary artery or coronary artery fistulas.

Accuracy, image quality and radiation dose comparison of high-pitch spiral and sequential acquisition on 128-slice dual-source CT angiography in children with congenital heart disease

To compare accuracy, image quality and radiation dose between high-pitch spiral and sequential modes on 128-slice dual-source computed tomographic (DSCT) angiography in children with congenital heart disease (CHD). Forty patients suspected with CHD underwent 128-slice DSCT angiography with high-pitch mode and sequential mode respectively. All the anomalies were confirmed by the surgical and/or the conventional cardiac angiography (CCA) findings. The diagnostic accuracy, the subjective and objective image quality and effective radiation doses were compared. There was no significant difference in diagnostic accuracy (χ ( 2 ) = 0.963, P > 0.05), the objective parameters for image quality (P > 0.05) and the image quality of great vessels (u = 167.500, P > 0.05) between the two groups. The image quality of intracardiac structures and coronary arteries was significantly better in the sequential mode group than that in the high-pitch group (u = 112.500 and 100.000, P < 0.05). The mean effective dose in high-pitch group (0.17 ± 0.05mSv) was significantly lower (t = 5.287, P < 0.05) than that in the sequential mode group (0.29 ± 0.09mSv). Both the high-pitch and the sequential modes for 128-slice DSCT angiography provide high accuracy for the assessment of CHD in children, while the high-pitch mode, even with some image quality decrease, further significantly lowers the radiation dose. • Modern CT provides excellent anatomical detail of congenital heart disease. • Dual source CT systems offer high-pitch spiral and sequential modes. • The high-pitch mode provides high accuracy for the assessment of CHD. • A few images using the high-pitch mode were occasionally slightly degraded. • But the high-pitch mode significantly lowers the radiation dose.

CT Perfusion and CT Angiography in children and juvenile patients during an attack of migraine with aura

Aims: The pathophysiology of migraine is not yet fully understood and stroke has to be included in differential diagnosis. The neurogenic theory is confirmed by neuroimaging studies with functional MRI during auras indicating that the decreases in cortical bloodflow are not sufficient to cause ischemia and the subsequent vasodilatation is observed well after the beginning of headache. Neuroimaging descriptions during migraine attacks are limited to MRI, but this technology is not widely available on a 24h basis. Recent developments in CT technology allows high speed volumetric data acquisition and generation of perfusion maps.

Children Suspected of Having Pulmonary Embolism: Multidetector CT Pulmonary Angiography—Thromboembolic Risk Factors and Implications for Appropriate Use

To evaluate thromboembolic risk factors for pulmonary embolism (PE) detected by using computed tomographic (CT) pulmonary angiography in children and to determine whether such information could be used for more appropriate use of CT pulmonary angiography in this patient population. The institutional review board approved this HIPAA-compliant retrospective study and waived the need for patient informed consent. Two hundred twenty-seven consecutive CT pulmonary angiography studies in 227 pediatric patients who underwent CT pulmonary angiography for clinically suspected PE at a single large pediatric referral hospital between July 2004 and March 2011 were evaluated. Age, sex, referral setting, and D-dimer result, as well as seven possible risk factors, were compared between patients with and those without PE. Multiple logistic regression modeling was used to identify the independent risk factors of PE. Receiver operating characteristic curve analysis was applied to determine the optimal cutoff number of risk factors for predicting a positive CT pulmonary angiography result for PE in children. Thirty-six (16%) of 227 CT pulmonary angiography studies were positive for PE. Five risk factors, including immobilization (P < .001), hypercoagulable state (P = .003), excess estrogen state (P = .002), indwelling central venous line (P < .001), and prior PE and/or deep venous thrombosis (P < .001), were found to be significant independent risk factors for PE. With use of two or more risk factors as the clinical threshold, the sensitivity of a positive PE result was 89% (32 of 36 patients), and the specificity was 94% (180 of 191 patients). It is unlikely for CT pulmonary angiography results to be positive for PE in children with no thromboembolic risk factors. The use of risk factor assessment as a first-line triage tool has the potential to guide more appropriate use of CT pulmonary angiography in children, with associated reductions in radiation exposure and costs.

Congenital Heart Disease in Children: Coronary MR Angiography during Systole and Diastole with Dual Cardiac Phase Whole-Heart Imaging

To assess the optimal timing for coronary magnetic resonance (MR) angiography in children with congenital heart disease by using dual cardiac phase whole-heart MR imaging. The local institutional review board approved this study, and informed consent was obtained from parents or guardians. Thirty children (13 girls; overall mean age, 5.01 years) were examined with a 1.5-T MR system. A free-breathing three-dimensional steady-state free precession dual cardiac phase sequence was used to obtain MR angiographic data during end-systolic and middiastolic rest periods. Vessel length, diameter, and sharpness, as well as image quality of the coronary artery segments, were analyzed and compared by using Bland-Altman plots, linear regression analysis, the t test, and Wilcoxon signed rank tests. Optimal coronary artery imaging timing was patient dependent and different for each coronary artery segment (36 segments favored end systole, 28 favored middiastole). In 15 patients (50%), different segments favored different cardiac phases within the same patient. Image quality and vessel sharpness degraded with higher heart rates, with a similar correlation for end systole (right coronary artery [RCA], 0.39; left main [LM] coronary artery, 0.46; left anterior descending [LAD] artery, 0.51; and left circumflex [LCX] artery, 0.50) and middiastole (RCA, 0.34; LM, 0.45; LAD, 0.48; and LCx, 0.55). Mean image quality difference or mean vessel sharpness difference showed no indication to prefer a specific cardiac phase. The optimal cardiac rest period for coronary MR angiography in children with congenital heart disease is specific for each coronary artery segment. Dual cardiac phase whole-heart coronary MR angiography enables optimal coronary artery visualization by retrospectively choosing the optimal imaging rest period.

Computed tomography angiography in children with cardiovascular disease: low dose techniques and image quality

Dose reduction techniques for computed tomography angiography (CTA) in children with cardiovascular diseases have the potential of reducing risks of radiation-induced cancer. To evaluate effectiveness of these techniques, both radiation dose and image quality must be compared. While clinically practical methods of estimating effective dose are available, there are no generally accepted metrics for the assessment of image quality in CTA. We introduce a measurable and reproducible image quality index, CTA QI. Using this index, along with calculated effective dose, we test the hypothesis that volume scan CTA delivers comparable image quality at substantially reduced radiation dose when compared to helical CTA. CTA QI is a measure of intraluminal contrast variation in three-dimensions, and it is calculated from standardized measurements of means and standard deviations of Hounsfield units in the thoracic descending aorta. From institutional database, 83 studies of CTA for thoracic cardiovascular diseases were retrospectively identified. CTA QI values were independently measured by two radiologists and compared using correlation. CTA QI and DLP-derived effective dose were compared for the following groups: non-cardiac gated wide-detector and helical CTA, ECG-synchronized retrospective wide-detector and helical CTA, ECG-synchronized wide detector retrospective and target technique CTA. Statistical significance was evaluated with the Student-t test. The correlations of CTA QI values between the radiologists were 0.83 and 0.92 for non-gated studies and ECG-synchronized studies respectively. Comparing non-gated volume scan CTA to helical CTA, there was a radiation dose reduction of 69% (P < 0.0001) without a significant change in CTA QI (1.4 ± 1.0 vs. 1.9 ± 1.4, P = 0.13). Comparing retrospective ECG-synchronized wide-detector CTA to helical CTA, there was a radiation dose reduction of 46% (P < 0.0001) with and improvement in CTA QI (1.0 ± 0.8 vs. 3.7 ± 3.4, P < 0.01). Comparing ECG-synchronized wide-detector target CTA to retrospective CTA, there was a radiation dose reduction of 68% (P < 0.0001, but at the cost of a significant reduction in CTA QI (2.0 ± 1.0 vs. 0.8 ± 0.4, P < 0.0044). CTA QI is a simple, reproducible metric of image quality suited for comparing CTA studies. Using this quality index, we establish that CTA performed with wide-detector scan techniques can yield substantially lower radiation dose without compromising diagnostic imaging quality. A wide-detector target technique can further reduce effective dose compared to wide-detector retrospective ECG-synchronization, but with a reduction in image quality.

The applications of non-ECG-gated MSCT angiography in children with congenital heart disease

BackgroundTo minimize radiation exposure during a multi-slice computed tomography (MSCT) examination in children with congenital heart disease (CHD), we assessed diagnostic value and the various applications of MSCT without electrocardiography (ECG)-gated image acquisition. MethodsThree-dimensional (3D) images were reconstructed to include volume rendering and differential color-coding of the arteries and veins. The vessel diameter in MSCT was measured with CT attenuation profiles and compared with that of angiography. Ventricular volumetry was initially validated by phantom experiment and followed by comparison with that of cine-angiography (n=15). Simulation for surgical operation was performed to evaluate the possibility of an intraventricular conduit in patients diagnosed with a double outlet right ventricle. ResultsDifferential color-coding was able to provide accurate and understandable anatomical structure in CHD. The diameter of the descending aorta measured in MSCT correlated well with the values obtained by angiography (r2=0.86). According to the results of the phantom experiment, ventricular volume was studied in patients whose heart rate was faster than 120beat/min. The left and the right ventricular volume in MSCT correlated well with values obtained by cine-angiography (r2=0.98 for RV, r2=0.94 for LV). Simulative operation of intraventricular rerouting provided appropriate indication for biventricular repair in patients diagnosed with a double outlet right ventricle. ConclusionsNon-ECG-gated MSCT angiography is applicable for precise anatomical diagnosis, ventricular volumetric study, and simulation surgery in children with CHD.

CT Angiography in Children with Penetrating Injuries Related to ATV Accidents

CT Angiography in Children with Penetrating Injuries Related to ATV Accidents