Perfusion In Children Research Articles

Application of Three-Dimensional Pseudocontinuous Arterial Spin Labeling Perfusion Imaging in the Brains of Children With Autism.

ObjectiveTo explore the application of three-dimensional pseudocontinuous arterial spin labeling (3D-PCASL) perfusion imaging in the brains of children with autism and to understand the characteristics of cerebral blood perfusion in children with autism.MethodsA total of 320 children with autism (160 men and 160 women) aged between 2 and 18 years and 320 age- and sex-matched healthy children participated in the study. All children were scanned by 3.0 T magnetic resonance axial T1 fluid-attenuated inversion recovery (FLAIR), T2 FLAIR, 3D-T1, and 3D-PCASL sequences. After postprocessing, cerebral blood flow (CBF) values in each brain region of children with autism and healthy children at the same age were compared and analyzed. Furthermore, CBF characteristics in each brain region of autistic children at various ages were determined.ResultsThe CBF values of the frontal lobe, hippocampus, temporal lobe, and caudate nucleus of children with autism are lower than those of healthy children (P < 0.05). Additionally, as the ages of children with autism increase, the number of brain regions with decreased CBF values gradually increases. A receiver operating characteristic (ROC) analysis results show that the CBF values of the frontal lobe, hippocampus, temporal lobe, and caudate nucleus can distinguish children with autism [area under the ROC curve (AUC) > 0.05, P < 0.05].ConclusionThe 3D-PCASL shows lower brain CBF values in children with autism.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier: ChiCTR2000034356.

Quantitative assessment of renal perfusion in children with UPJO by contrast enhanced ultrasound: A pilot study

Contrast-enhanced ultrasound (CEUS) is a new potential modality for the quantitative evaluation of the microvascular perfusion of a parenchymal organ. To prospectively and quantitatively analyse the role of CEUS in evaluating renal perfusion for assessing renal function in children with ureteropelvic junction obstruction (UPJO). The study protocol was approved by the local ethics committee, and written informed consent was obtained from the patients' parents or guardians. Ultrasonography, CEUS, and radioisotope renography were performed for 51 children (42 boys, 9 girls; mean age, 6.75±4.14 years) with unilateral UPJO. The slope of the ascending curve (A), time to peak (TTP), peak intensity (PI), and area under the curve (AUC) were recorded during CEUS; quantitative data were calculated by QLab system (semiautomated border tracking, Philips Healthcare) software. Sensitivity and specificity values were determined for CEUS with respect to radioisotope renography. CEUS was used to evaluate 102 kidneys in 51 patients, for which the perfusion time-intensity curve (TIC) was determined. The TIC of renal cortical perfusion in all groups showed an asymmetrical single-peak curve, which could be clearly distinguished between the experimental group and the control group. Compared with the control group, the experimental group showed a markedly prolonged TTP but a significantly decreased A (P<0.05). There was no significant correlation between the AUC, PI and differential renal function (DRF), but the correlation coefficient between TTP, A and DRF remained significant (p<0.001).The receiver operating characteristic (ROC) curves drawn to differentiate DRF using the TTP value yielded an area under the ROC curve (AUROC) of 0.86. For a quantitative assessment of DRF less than 40% by CEUS, the sensitivity and specificity values were 92.86% and 76.14%, respectively. Unlike in previous studies, no significant difference in the AUC or PI was found between the control group and the experimental group in this study (P>0.05). Renal blood perfusion could not be evaluated overall by CEUS. Parenchymal thinning may be considered a limitation to CEUS. This preliminary experience represents the first report of evaluating the diagnostic value of CEUS in assessing renal function in children with UPJO. CEUS is a highly sensitive, rapid, and cost-effective diagnostic imaging modality for detecting and monitoring renal function noninvasively.

Optical coherence tomography angiography in healthy children: A comparison of macular structure.

The purpose of the present study was to investigate the perfusion density (PD) of macular superficial (SCP) and deep capillary plexus (DCP), the size of foveal avascular zone (FAZ) and central macular thickness (CMT) in healthy children using optical coherence tomography angiography (OCT-A). About 206 eyes of 111 children were analyzed. The correlation of gestational age (GA), birth weight (BW), age, sex, refractive errors, and visual acuity (VA) with OCT-A parameters were investigated. The mean PD of the fovea and the mean FAZ area of SCP were 17.1% (DS: 4.26) and 234.47 (DS: 106.39) µm2. The mean PD of the fovea and the mean FAZ area of DCP were 13.5% (DS: 5.23) and 298.32 (DS: 112.37) µm2. Superficial and deep FAZ areas were not correlated with sex, age, BW, refractive errors, or VA. FAZ area of SCP was correlated with foveal PD (r = -0.76) and with CMT (r = -0.68). FAZ area of DCP was correlated with foveal's PD (r = -0.61). There was no correlation between CMT and refractive errors. OCT-A may provide a non-invasive and reliable approach to evaluate macular perfusion in children. As the FAZ area, PD, and CMT change during the growth period, we performed established a reference range for different ages.

Impaired Myocardial Perfusion on Stress CMR Correlates With Invasive FFR in Children With Coronary Anomalies.

Invasive fractional flow reserve (FFR) is considered the gold standard to evaluate coronary artery flow. Stress cardiovascular magnetic resonance (sCMR) is an emerging non-invasive tool to evaluate myocardial perfusion in children. We sought to compare sCMR with FFR to determine impaired intracoronary flow in children with anomalous aortic origin of a coronary artery (AAOCA) and/or myocardial bridge (MB) who presented concern for myocardial ischemia. From December 2012 to May 2019, AAOCA and/or MB patients (<20 years old) were prospectively enrolled and underwent sCMR and FFR. Abnormal sCMR included perfusion/regional wall-motion abnormality in the involved coronary distribution. FFR was performed at baseline and with dobutamine/regadenoson and considered abnormal if <0.8 in the affected coronary segment. Of 376 patients evaluated, a total of 19 (age range, 0.2-17 years) underwent 24 sets of sCMR and FFR studies, with 5 repeat studies following intervention. Types of anomalies included 6 isolated MB/normal CA origins, 5 single CAs, 5 left AAOCAs, and 3 right AAOCAs. Seventeen patients (89.5%) had MB/intramyocardial course - 14 involving the left anterior descending coronary artery and 3 with multivessel involvement. sCMR correlated with FFR in 19/24 sets (7 sCMR and FFR positive, 12 sCMR and FFR negative) and it did not correlate in 5/24 sets. The positive percent agreement was 77.8%, negative percent agreement was 80.0%, and overall percent agreement was 79.2%. Assessment of myocardial perfusion using non-invasive sCMR concurred with FFR, particularly if performed with close proximity in time, and may contribute to risk stratification and decision making in children with AAOCA and/or MB.

Scoring system for poor limb perfusion after limb fracture in children.

BACKGROUNDAssessment of the vascular status following limb fracture in children is important to evaluate the risk of compartment syndrome, which is an emergency condition.AIMTo establish a simple and efficient grading scale of limb perfusion in children undergoing surgery for limb fracture.METHODSThis retrospective study included pediatric patients with a limb fracture and postoperative plaster fixation who were admitted at The Department of Pediatric Orthopedics of Xinhua Hospital between February 2017 and August 2017. The outcome was poor limb perfusion, which is defined as the postoperative use of mannitol. The children were divided into two groups: The normal perfusion group and the poor perfusion group. Key risk factors have been selected by univariable analyses to establish the Grading Scale for Vascular Status.RESULTSA total of 161 patients were included in the study: 85 in the normal perfusion group and 76 in the poor perfusion group. There were no significant differences in age, sex, body mass index, ethnicity, cause of fracture, fixation, or site of fracture between the two groups. After surgery, the skin temperature (P = 0.048) and skin color (P < 0.001) of the affected limb were significantly different between the two groups. The relative risk and 95% confidence interval for skin temperature of the affected limb, skin color, and range of motion of the affected limb are 2.18 (1.84-2.59), 2.89 (2.28-3.66), and 2.16 (1.83-2.56), respectively. The grading scale was established based on those three factors (score range: 0-3 points). Forty-one patients (32.5%) with score 0 had poor limb perfusion; all patients with scores 1 (n = 32) and 2 (n = 3) had poor limb perfusion (both 100%).CONCLUSIONIn children undergoing surgery for limb fracture, a higher Grading Scale for Vascular Status score is associated with a higher occurrence of poor limb perfusion. A prospective study is required for validation.

The Chft+ Sensor: A Novel Method to Measure Perfusion Abnormalities in Sickle Cell Disease

Introduction: Peripheral perfusion limitation is a potential biomarker of the severity and progression of sickle cell disease (SCD). Currently, there exists no direct means of quantifying perfusion deficits in SCD patients. Transcranial doppler ultrasonography offers a surrogate measure of perfusion and is highly operator dependent. Routine clinical screening of perfusion abnormalities with alternative modalities (e.g., positron emission tomography and magnetic resonance imaging) is challenging given high cost, requirement for sedation in young children, and need for trained personnel. The Combined Heat-Flux Temperature Sensor (CHFT+) is a novel noninvasive bio-heat perfusion sensor that measures peripheral perfusion in real time at depths of up to 1 cm by applying a minimal amount of heat to the skin surface. Because perfusion limitation is a hallmark of SCD, an improved understanding of its pathophysiology could potentially empower both patients and their physicians. The aim of this study was to evaluate the ability of the CHFT+ to detect differences in peripheral perfusion between healthy volunteers and patients with SCD. Materials and Methods: The present study is an ongoing, non-randomized pilot study that aims to test the CHFT+ sensor's ability to detect impaired perfusion is pediatric SCD patients. We are actively enrolling pediatric patients (age 3-17) with SCD and healthy volunteers from 2 pediatric clinics to test the sensor. Peripheral perfusion measurements were obtained at 5 locations on the body (e.g., forehead, forearms, palms). All measurements were normalized against forehead perfusion values to account for individual variations. An independent-samples t-test was conducted to compare average rates of perfusion in patients with SCD and in healthy volunteers. The goal enrollment for this study is 52 patients (26 with SCD, 26 healthy controls) to detect a two-fold difference in perfusion with a power of 0.80. Interim Results and Discussion: To date, 31 participants have been enrolled, 10 (32%) of whom were patients with SCD. Overall, average perfusion rates were lower in the SCD group when compared to the healthy group, although these differences were not statistically significant. Representative measurements of perfusion in the right and left forearms, normalized against forehead rates, are shown in Figure 1. Normalized left forearm perfusion in healthy controls vs. SCD patients: avg = 1.77, SD = 0.95 vs. avg = 1.28, SD = 0.52, respectively [t(27) = 1.80, p = 0.08]; see Fig. 1a. Normalized right forearm perfusion in healthy controls vs. SCD patients: avg = 1.80, SD = 1.01 vs. avg = 1.31, SD = 0.60, respectively [t(25) = 1.55, p = 0.13]); see Fig. 1b. Conclusions:At this time, our data suggest that the novel CHFT+ sensor is capable of detecting a modest difference in peripheral perfusion in children with SCD versus healthy controls, but this difference is not statistically significant due to limited enrollment. Additional enrollment will further define the utility of the CHFT+ sensor in this clinical population. Future studies should evaluate the sensor's capability to detect perfusion deficits in the adult SCD population, as well as measure perfusion variations that occur during SCD vaso-occlusive crises. Disclosures Diller: FluxTeq:Other: Partner.

Evaluation of the Optic Disc and Macula in Healthy Children Using Optical Coherence Tomography Angiography

Objectives:To perform the measurements of the optic disc and macula in healthy children using optical coherence tomography angiography (OCTA) in order to determine the normative data values and compare these by age, gender, spherical equivalent (SE), and axial length (AL).Materials and Methods:A total of 146 eyes belonging to 146 healthy children (74 girls, 72 boys) aged 6 to 16 years were included in this prospective study. Refraction and biometry measurements were performed. Retinal nerve fiber layer thickness (RNFLT), central macular volume, and central macular thickness (CMT) were measured by optical coherence tomography (OCT) after dilatation. Using the OCTA device, foveal avascular zone (FAZ) area, vascular density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the macula, and the VD of the radial peripapillary capillary plexus (RPCP) of the optic disc were recorded.Results:The mean age of the study group was 11.27±3 years, the mean AL was 23.39±1.18 mm and the mean SE was -1.31±1.61 diopters. The mean FAZ area was 0.3±0.09 mm2, the mean SCP-VD was 43.88±3.4%, the mean DCP-VD was 39.6±3.55%, and the mean RPCP-VD was 52.47±3.42%. When the relationship between the OCTA measurements and the SE and AL values were analyzed, there was no statistical significance (p>0.05). When age and OCTA measurements were compared, only DCP-VD values were found to significantly decrease with increasing age (p=0.015). There was no significant difference in OCTA measurements based on gender (p>0.05). Similarly, no statistical age-based differences were observed in RNFLT, CMV and CMT values (p>0.05).Conclusion:With its short procedure time and no dye requirement, OCTA can be safely used in the evaluation of the optic disc and macular perfusion in children. Determination of normative values in children will be useful in detecting pathologic changes in tissue in patients with retinal diseases.

Disrupted Regional Cerebral Blood Flow in Children With Newly-Diagnosed Type 1 Diabetes Mellitus: An Arterial Spin Labeling Perfusion Magnetic Resonance Imaging Study.

Object: Diabetes is associated with cerebral vascular dysfunction and increased vascular cognitive impairment. The objective of this study was to use arterial spin labeling (ASL) perfusion-weighted magnetic resonance imaging to investigate whether cerebral perfusion was changed in newly-diagnosed children with type 1 diabetes mellitus (T1DM) and the possible relationship between aberrant cerebral blood flow (CBF) with cognitive as well as clinical variables.Methods: Between January 2017 and February 2018, 34 children with newly-diagnosed T1DM and 34 age, gender, and education-matched healthy controls were included. Three dimensional pseudo-continuous ASL perfusion MRI was used to evaluate CBF. A conventional T2WI sequence was added to exclude intracranial disease. Regions with CBF differences between T1DM children and the controls were detected via voxel-wise comparisons in REST software. Associations among the result of neuropsychological test, clinical variables, and CBF values of different brains were investigated by using partial correlation analysis.Results: Compared with the controls, T1DM children show decreased CBF in the left calcarine and postcentral gyrus, and right precentral gyrus. The perfusion in the postcentral gyrus was positively correlated with IQ performance. No significant correlations were found between CBF and HbA1c, blood glucose level before imaging and IQ in other brain regions in T1DM children.Conclusion: There is an abnormal cerebral perfusion in children with newly diagnosed T1DM. The visual and sensorimotor areas are brain areas where perfusion is prone to change at the beginning of T1DM. Our study provided clues for cerebral pathophysiological changes in the initial stage of T1DM.

Altered cerebral perfusion in children with Langerhans cell histiocytosis after chemotherapy.

Children with Langerhans cell histiocytosis (LCH) may develop a wide array of neurological symptoms, but associated cerebral physiologic changes are poorly understood. We examined cerebral hemodynamic properties of pediatric LCH using arterial spin-labeling (ASL) perfusion magnetic resonance imaging (MRI). A retrospective study was performed in 23 children with biopsy-proven LCH. Analysis was performed on routine brain MRI obtained before or after therapy. Region of interest (ROI) methodology was used to determine ASL cerebral blood flow (CBF) (mL/100g/min) in the following bilateral regions: angular gyrus, anterior prefrontal cortex, orbitofrontal cortex, dorsal anterior cingulate cortex, and hippocampus. Quantile (median) regression was performed for each ROI location. CBF patterns were compared between pre- and posttreatment LCH patients as well as with age-matched healthy controls. Significantly reduced CBF was seen in posttreatment children with LCH compared to age-matched controls in angular gyrus (P=.046), anterior prefrontal cortex (P=.039), and dorsal anterior cingulate cortex (P=.023). Further analysis revealed dominant perfusion abnormalities in the right hemisphere. No significant perfusion differences were observed in the hippocampus or orbitofrontal cortex. Perfusion in specific cerebral regions may be consistently reduced in children with LCH, and may represent effects of underlying disease physiology and/or sequelae of chemotherapy. Studies that combine a formal cognitive assessment and hemodynamic data may further provide insight into perfusion deficits associated with the disease and the potential neurotoxic effects in children treated by chemotherapy.

Cerebral blood flow imbalance is associated with motor outcome after pediatric arterial ischemic stroke.

Cerebral hemodynamics after arterial ischemic stroke (AIS) in children are largely unknown. This study aims to explore long-term cerebral perfusion balance of vital tissue and its relation to motor outcome after childhood AIS. Patients diagnosed with childhood AIS (≤16 years at diagnosis, time since stroke ≥2 years) and typically developing peers were examined. Hemiparesis was classified according to the Pediatric Stroke Outcome Measure. Manual ability was assessed using the ABILHAND-Kids questionnaire. Cerebral blood flow was measured by arterial spin labeling and analyzed in the following brain regions: the hemispheres, the territory of the anterior cerebral artery (ACA), the middle cerebral artery (MCA), and in subregions of the MCA territory (MCA anterior, middle, posterior). To assess cerebral perfusion balance, laterality indices were calculated using cerebral blood flow in the ipsi- and contralesional hemisphere. Laterality indices were compared between stroke patients with and without hemiparesis, and peers. Twenty participants diagnosed with AIS were included (12 boys, 8 girls; mean age 14.46±4.96 years; time since stroke 8.08±3.62 years); 9 (45%) were diagnosed with hemiparesis. Additionally, 47 typically developing peers (21 boys, 26 girls; mean age 14.24±5.42 years) were studied. Laterality indices were higher in stroke patients and oriented to the contralesional hemisphere in all brain regions except the ACA territory and MCA posterior subregion. This was significantly different from peers, who showed balanced laterality indices. There was a significant correlation between laterality indices and manual ability, except in the ACA territory. AIS is associated with long-term alterations of cerebral blood flow in vital tissue, even in patients without hemiparesis. The degree of imbalance of cerebral perfusion in children after AIS is associated with manual ability.

Survey of practice patterns and preparedness for endovascular therapy in acute pediatric stroke.

Endovascular therapy benefits selected adults with acute stroke while data are lacking for children. The purpose of this study was to assess physician practice and institutional preparedness for endovascular therapy in pediatric stroke. A link to an anonymous online survey was sent to members of the International Pediatric Stroke Study (IPSS) group about physician experience with endovascular therapy, likelihood of treatment for provided clinical vignettes, and institutional readiness for the delivery of endovascular therapy to children. Thirty-one pediatric physicians with a mean of 11years (SD 7.1) of experience responded. All but two would consider endovascular therapy in a child, and 20 (64.5%) had recommended endovascular therapy for a child in the preceding year. Most (n = 19, 67.9%) did not commit to an age minimum for endovascular therapy. Sixteen (57.1%) would consider treatment up to 24h after symptom onset with 19 (67.9%) respondents reporting that their practice changed after the 2018 American Heart Association guidelines extended the time window for endovascular therapy in adults. Seventeen (60.7%) preferred imaging that included perfusion in children presenting beyond 6h. Nineteen (70.4%) had institutional endovascular therapy criteria. Physicians in larger pediatric groups had more "likely to treat" responses on the clinical vignettes than physicians working in smaller groups (11.7 vs. 6.1, p < 0.05). Pediatric stroke physicians are largely willing to consider endovascular therapy with most changing their practice according to adult guidelines, though experience and selection criteria varied. These findings may help to inform consensus guidelines and clinical trial development.

Prediction of Shock by Peripheral Perfusion Index.

To detect occurrence of clinical shock and impending shock by monitoring Peripheral Perfusion Index (PI). In this study, 100 children aged 1 mo to 12 y of age who needed hemodynamic monitoring were included and categorized into five age groups. Demographic data, nutritional status, vital parameters, perfusion index and laboratory parameters were recorded. Hemodynamic monitoring was done for 48h. In total, 65 and 35 children were admitted with and without features of shock respectively. Nine hundred thirty six hemodynamic measurements were taken and analyzed. Correlation between perfusion index, blood pressures and clinically assessed shock were done. Clinical shock can be reasonably detected when perfusion index value is less than 1.15 in children less than 3 y of age, less than 1.25 in 3 to 10 y of age and less than 1.55 in 10 to 12 y of age. These values had high sensitivity and low false positivity in detecting clinically assessed shock in that particular age group. PI had good correlation with pulse pressure and systolic blood pressure in all age groups and weak correlation with mean arterial blood pressure and diastolic blood pressure. A 57% reduction in PI value from the baseline value may predict impending shock in children. Perfusion index can be used as a non-invasive, continuous parameter to monitor peripheral perfusion in children and to detect impending shock.

Analysis of Retinal Perfusion in Children, Adolescents, and Young Adults with Type 1 Diabetes Using Optical Coherence Tomography Angiography.

We performed a cross-sectional study to analyze the retinal vasculature in children, adolescent, and young adults with type 1 diabetes using optical coherence tomography angiography (OCTA). Patients underwent funduscopic examination for diabetic retinopathy (DR) screening during an annual visit for the screening of diabetes-related complications which included the evaluation of glycated hemoglobin (HbA1c), microalbuminuria, lipid profile, arterial pressure, and neurological assessment. In addition, OCTA of the retinal vasculature was performed. Quantitative analysis of the OCTA images evaluated the vessel density at the superficial (SCP) and deep (DCP) capillary plexus of the retina. Structural vascular alterations were evaluated qualitatively. Results were compared to those obtained in a group of healthy age-, sex-, and pubertal stage-matched controls. The effect of age, disease duration, age at the disease onset, mean HbA1c since the onset, and lipid profile on vascular density was tested. Fifty-three patients (median age 15.5, IQR 12.4-19.4 years; 57% females) with type 1 diabetes and 48 controls were enrolled. The median (IQR) HbA1c was 7.6% (60 mmol/mol) (6.9-8.1%, 52-65 mmol/mol), and the median (IQR) duration of disease was 6.0 (3.3-10.3) years. Mean vessel density measured with OCTA was lower in patients compared to controls with the temporal sector showing the highest difference both in the SCP (0.55 vs. 0.57, p < 0.001) and the DCP (0.63 vs. 0.65, p < 0.001). None of the predictors was associated with the superficial and deep vascular densities. Only 2 patients had clinically detectable DR. Microvascular structural changes were found on OCTA in both of these patients and in one without funduscopic alterations. In conclusion, patients with type 1 diabetes without clinically detectable DR had decreased capillary density compared to controls on OCTA images. These findings may provide useful information for the screening and the management of patients with type 1 diabetes. Further studies are needed to confirm our results and their clinical relevance.

Brain DSC MR Perfusion in Children: A Clinical Feasibility Study Using Different Technical Standards of Contrast Administration.

Dynamic susceptibility contrast MR perfusion imaging has limited results in children due to difficulties in reproducing technical standards derived from adults. This prospective, multicenter study aimed to determine DSC feasibility and quality in children using custom administration of a standard dose of gadolinium. Eighty-three consecutive children with brain tumors underwent DSC perfusion with a standard dose of gadobutrol administered by an automated power injector. The location and size of intravenous catheters and gadobutrol volume and flow rates were reported, and local and/or systemic adverse effects were recorded. DSC was qualitatively evaluated by CBV maps and signal intensity-time curves and quantitatively by the percentage of signal drop and full width at half-maximum, and the data were compared with the standards reported for adults. Quantitative data were grouped by flow rate, and differences among groups were assessed by analysis of covariance and tested for statistical significance with a t test. No local or systemic adverse events were recorded independent of catheter location (63 arm, 14 hand, 6 foot), size (24-18 ga), and flow rates (1-5 mL/s). High-quality CBV maps and signal intensity-time curves were achieved in all patients, and quantitative evaluations were equal or superior to those reported for adults. No significant differences (P ≥ .05) were identified among the higher-flow-rate groups in the quantitative data. A custom administration of a standard dose of gadobutrol allows safe and high-quality DSC MR perfusion imaging in children.

Resting state cerebral blood flow with arterial spin labeling MRI in developing human brains.

The development of brain circuits is coupled with changes in neurovascular coupling, which refers to the close relationship between neural activity and cerebral blood flow (CBF). Studying the characteristics of CBF during resting state in developing brain can be a complementary way to understand the functional connectivity of the developing brain. Arterial spin labeling (ASL), as a noninvasive MR technique, is particularly attractive for studying cerebral perfusion in children and even newborns. We have collected pulsed ASL data in resting state for 47 healthy subjects from young children to adolescence (aged from 6 to 20 years old). In addition to studying the developmental change of static CBF maps during resting state, we also analyzed the CBF time series to reveal the dynamic characteristics of CBF in differing age groups. We used the seed-based correlation analysis to examine the temporal relationship of CBF time series between the selected ROIs and other brain regions. We have shown the developmental patterns in both static CBF maps and dynamic characteristics of CBF. While higher CBF of default mode network (DMN) in all age groups supports that DMN is the prominent active network during the resting state, the CBF connectivity patterns of some typical resting state networks show distinct patterns of metabolic activity during the resting state in the developing brains.

Optical Coherence Tomography-Based Angiography in Retinal Artery Occlusion in Children

Purpose: To evaluate the role of optical coherence tomography (OCT)-based angiography (OCTA) in the diagnosis and monitoring of pediatric patients with retinal artery occlusion (RAO). Material and Methods: This retrospective study was conducted at the Department of Ophthalmology, The Children's Memorial Health Institute, in Warsaw between March 2015 and May 2016. Every patient underwent a complete ophthalmological examination. The diagnosis of the disease was based on fundus examination and fluorescein angiography (FA). OCT and OCTA were performed at baseline and every follow-up visit. Results: Four patients (4 eyes) (2 boys/2 girls, age 8-16 years) with RAO were enrolled in the study. In all cases, initial OCTA images revealed typical ischemic changes in superficial and deep retinal capillary plexuses. Follow-up OCTA revealed increasing areas of ischemia in the RAO region and persistent narrowing of the arteries. The loss of capillary network and the darker, smooth background due to ischemia were visible on OCTA images. Conclusions: OCTA enables clear visualization of progressive impairment of the retinal vascular perfusion in children with RAO and may be an alternative to the standard FA. Further studies are needed to confirm our results and establish the role of OCTA in pediatric patients.

Evaluation of femoral head viability via bone scintigraphy in the postoperative pediatric patient.

Evaluating postoperative patients with hardware is challenging following surgical intervention for hip maladies such as femoral neck fractures and slipped capital femoral epiphysis (SCFE). These children are at increased risk of developing avascular necrosis, and imaging may be requested to confirm or exclude this diagnosis. Children with Legg-Calvé-Perthes disease can be monitored for restoration of blood flow to the capital femoral epiphysis to guide management and help with prognosis. Although MRI is sensitive for detecting early avascular necrosis, the presence of hardware degrades image quality. This report examines the utility of bone scans for evaluating femoral head perfusion in children who have undergone surgery for femoral neck fractures, SCFE or Legg-Calvé-Perthes disease. A retrospective review of 20 patients (22 scans) after fixation for femoral neck fracture, SCFE or Legg-Calvé-Perthes disease from 2012 to 2015 was performed. The bone scan findings were correlated with the intraoperative findings or clinical follow-up. Twenty-one of the 22 (95%) bone scans in 19 of the 20 (95%) patients demonstrated findings consistent with clinical outcomes and/or the intraoperative appearance of the femoral head. Four of 20 patients (20%) had bone scan features of avascular necrosis, defined as "absent" or "moderately diminished" femoral head activity, which were confirmed intraoperatively and resulted in poor outcomes. Radionuclide imaging of hips in the postoperative setting is a valuable modality for assessing the risk of avascular necrosis, a complication of femoral neck fractures and SCFE and for evaluating the restoration of flow to the capital femoral epiphyses of children with Legg-Calvé-Perthes disease.

In vivo assessment of macula in eyes of healthy children 8 to 16 years old using optical coherence tomography angiography

The purpose of the present study was to investigate the vascular flow density (VD) of macular superficial (SCP), deep capillary plexus (DCP), and choriocapillaris and the size of the foveal avascular zone (FAZ) area in healthy children using optical coherence tomography angiography (OCTA). The potential associations of age, sex, intraocular pressure, body mass index, spherical equivalent, and axial length with OCTA parameters were also investigated. A total of 75 eyes from 75 healthy children were included for analysis, with the mean age 11.51 ± 1.91 years (range, 8–16 years). At the level of the SCP, mean VD and mean FAZ area were, respectively, 54.29 ± 2.25% and 0.290 ± 0.109 mm2. At the level of the DCP and choriocapillaris, mean VD were 60.19 ± 1.76% and 66.58 ± 1.33%, respectively. After adjustment on the signal strength index, there was no significant correlation between age and all OCTA parameters. Intra-observer repeatability was 0.91, 0.82, and 0.88 in the SCP, DCP and choriocapillaris, respectively. In healthy eyes of children, only sex has a significant influence on the FAZ area. OCTA may provide a noninvasive and reliable approach for evaluating macular perfusion in children, although sex-related variations should be considered.

Transfusion Therapy and Hydroxyurea Improves Cerebrovascular Reserve and Perfusion in Children with Sickle Cell Anemia: An MRI Study

Introduction: The pathophysiology of overt stroke in children with sickle cell anemia (SCA) is not well understood. However, a compromised cerebral hemodynamic environment, marked by elevated cerebral blood flow (CBF) and impaired cerebrovascular reserve are thought to play a critical role. Currently, stroke prevention is based on chronic transfusion therapy (Tx). However, Tx suffers from several complications including; iron overload, risk of infection, and hyperhemolysis reactions. Hydroxyurea (HU) is a well-tolerated myelosupressive agent, which increases fetal hemoglobin (HbF) and is being tested as an alternative to Tx for primary stroke prevention in children with SCA. However, it is currently not clear how either Tx or HU treatment compare with respect to their effects on the precarious hemodynamic environment in children with SCA. Therefore, we assessed cerebrovascular reserve by obtaining MR-based measures of cerebrovascular reactivity (CVR), defined as the change in blood flow in response to a vasoactive stimulus. Considering that HU and Tx both act to dilute HbS and increase oxygen carrying capacity, we hypothesized that SCA children treated with HU and Tx will exhibit increased CVR and decreased CBF compared to age-matched, non-treated, SCA children.Methods: 21 SCA (HbSS) untreated SCA children (5M/16F; avg age 14.1 ± 2.42), 16 SCA children treated with HU (10M/6F; avg age 14.0 ± 2.49) and 7 patients on Tx (3M/4F ; avg age 13.0 ± 1.81) were recruited from the Haematology Department at The Hospital for Sick Children. Exclusion criteria were; history of overt stroke, vasoocclusive crises, and febrile illness within 30 days of the scan. CVR was obtained using a blood-oxygen level-dependent (BOLD) MRI sequence in combination with a CO2 breathing challenge. CO2 was administered via a re-breathing mask in 4 alternating cycles of 40 mmHg PETCO2 for 60 seconds and 45 mmHg PETCO2 for 45 seconds. BOLD MRI signal changes were aligned and regressed against the CO2 waveform on a voxel-wise bases using FSLv4.1 to yield the raw CVR maps. The CVR maps were then co-registered to anatomical images. CBF measurements were obtained using a pulsed arterial spin labeling (pASL) sequence and were quantified from the mean signal difference between the ASL tag and control images using a single compartment kinetic model. The Student's t-test was used to test for significant differences between CVR, CBF, and blood parameters between the HU, Tx, and No Treatment groups. Blood parameters were obtained from complete blood counts.Results: Blood parameters are shown in Table 1.HU-treated SCA children exhibited significantly higher Hct and CVR in both the gray and white matter compared to the No Treatment group, with no significant differences in CBF. The Tx-treated SCA group exhibited higher Hct, CVR in the gray matter, and decreased CBF in both the grey and white matter compared to the No Treatment group (see Figure 1).Conclusions: Both the HU and Tx-treated SCA groups demonstrated significantly improved cerebrovascular reserve compared to the No Treatment group. The increase vascular reserve may be a result of HU and Tx decreasing the severity of anemia thereby reducing the baseline vessel tone necessary to sufficiently perfuse the cerebral tissue. CBF was significantly reduced in the Tx-treated group compared to the No Treatment group, which may be due to the higher oxygen content provided by Tx. Interestingly, CBF was not significantly different between the HU-treated and No Treatment group despite the HU-treated group having significantly greater hematocrit. This was surprising as a previous study using Doppler ultrasound (TCD) demonstrated that HU significantly reduces blood velocities (TCDv). However, unlike TCDv which are velocity measurements obtained at the large feeding arteries, pASL CBF values reflect perfusion at the tissue level. Further studies are required to fully compare TCDv and pASL measures of CBF as a means to monitor treatment effects in SCA patients.Table 1SCA: No TreatmentSCA: HydroxyureaSCA: TransfusionSample Size (N)21167Gender (M/F)5/1610/6*3/4Age (mean ± SD)14.1 ± 2.4214.0 ± 2.4913.0 ±1.81Hematocrit0.253 ± 0.0370.289 ± 0.034*0.308 ± 0.034¥Hemoglobin (g/L)86.4 ± 10.9101 ± 12.1*105 ± 11.2¥Hemoglobin F (%)-15.8 ± 8.073.01 ± 32.2Reticulocyte (%)9.4 ± 6.17.2 ± 3.6-MCV (fL)80.3 ± 10.894.9 ± 12.3*-SaO20.97 ± 0.030.99 ± 0.01-Neutrophils (K/uL)6.1 ± 3.14.2 ± 1.6*- [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Color Doppler dynamic tissue perfusion measurement: a novel tool in the assessment of renal parenchymal perfusion in children with vesicoureteral reflux.

IntroductionVesicoureteral reflux (VUR) occurs in 20–50% of children suffering from recurrent urinary tract infections (UTIs) and is associated with an increased risk of renal scarring and impaired renal function. Early detection of renal perfusion deterioration would allow for the implementation of more aggressive treatment and potentially prevent further damage to the renal parenchyma. The aim of the study was to assess renal parenchymal perfusions in children with recurrent UTIs with and without coexisting VUR, and compare the findings with the results of healthy patients.Material and methodsColor Doppler sonographic dynamic renal parenchymal perfusion measurements were performed with PixelFlux (Chameleon-Software, Germany) software in 77 children with recurrent UTIs and coexisting VUR and in 30 children with UTIs without VUR. The findings were compared with the results of 53 healthy children.ResultsCortical parenchymal perfusion of children suffering from UTIs and VUR was significantly reduced when compared to the control group. Statistically significant differences (p < 0.05) were found in all perfusion parameters (i.e. mean velocity (vmix), mean perfused area (Amix), mean perfusion intensity (Imix), tissue pulsatility index (TPI), and tissue resistance index (TRI)) between the control group and children suffering from UTIs and VUR, particularly VUR grades III and IV. There were no significant differences between the UTI group and the control group. No differences were found between the controls and VUR grade II.ConclusionsRenal parenchymal perfusion decreases significantly with higher grades of VUR.