Association between Early Basal Ganglia and Thalami Perfusion Assessed by Color Doppler Ultrasonography and Brain Injury in Infants with Hypoxic-Ischemic Encephalopathy: A Prospective Cohort Study.

OBJECTIVE: To evaluate associations between neurologic outcomes and early measurements of basal ganglia (BG) and thalamic (Th) perfusion using color Doppler ultrasonography (CDUS) in infants with hypoxic-ischemic encephalopathy (HIE). STUDY DESIGN: Prospective study of infants with mild (n = 18), moderate (n = 17), and severe HIE (n = 14) and controls (n = 17). Infants with moderate-severe HIE received therapeutic hypothermia (TH). CDUS was performed at 24-36 hours and brain magnetic resonance imaging (MRI) at a median of 10 days. Development was followed through 2.5-5 years. The primary outcome was the association between BG and Th perfusion and brain MRI injury. Secondary analyses focused on associations between perfusion measurements and admission neurologic examinations, MRI scores in infants treated with TH, and motor and sensory disability, or death. An exploratory analysis assessed the accuracy of BG and Th perfusion to predict brain MRI injury in infants treated with TH. RESULTS: Increased BG and Th perfusion on CDUS was observed in infants with severe MRI scores and those with significant motor and neurosensory disability or death through 2.5-5 years (P < .05). Infants with severe HIE showed increased BG and Th perfusion (P < .005) compared with infants with moderate HIE. No differences were identified between the between the control and mild HIE groups. Th perfusion ≥0.237 cm/second (Area under the curve of 0.824) correctly classified 80% of infants with severe MRI scores. CONCLUSIONS: Early dynamic CDUS of the BG and Th is a potential biomarker of severe brain injury in infants with HIE and may be a useful adjunct to currently used assessments.

The impact of high-frequency transducers on the sonographic measurements of the pyloric muscle thickness in infants.

BACKGROUND: Ultrasound is the modality of choice for the diagnosis of hypertrophic pyloric stenosis (HPS). The evolution of high-frequency transducers in ultrasound has led to inconsistent ways of measuring the pylorus. OBJECTIVE: To standardize the measurements and evaluate the appearance of the normal and hypertrophied pylorus with high-frequency transducers. MATERIALS AND METHODS: We retrospectively analyzed abdominal ultrasounds of infants with suspected HPS from January 2019-December 2020. We classified the layers of the pylorus while assessing the stratified appearance. Two pediatric radiologists measured the muscle thickness of the pylorus independently by two methods for interrater agreement. Measurement (a) includes the muscularis propria and muscularis mucosa. Measurement (b) includes only the muscularis propria. We also evaluated the echogenicity of the muscularis propria. The interrater agreement, mean, range of the muscle thickness, and the diagnostic accuracy of the two sets of measurements were calculated. RESULTS: We included 300 infants (114 F:186 M), 59 with HPS and 241 normal cases. There was a strong agreement between the readers assessed in the first 100 cases, and ICC was 0.99 (95% CI, 0.98-0.99). Measurement (a), median thickness is 2.4 mm in normal cases and 4.8 mm in HPS. Measurement (b), median thickness is 1.4 mm in normal cases and 4.0 mm in HPS. Measurement (a) has an accuracy of 89.7% (95% CI, 85.7-92.8%) with 98.3% sensitivity and 87.6% specificity. Measurement (b) has an accuracy of 98.0% (95% CI, 95.7-99.3%) with 89.8% sensitivity and 100.0% specificity. The pylorus stratification is preserved in all normal cases and 31/59 (52.5%) cases of HPS. There was complete/partial loss of stratification in 28/59 (47.5%) cases of HPS. In all HPS cases, the muscularis propria was echogenic. CONCLUSION: Measuring the muscularis propria solely has a better diagnostic accuracy, decreasing the overlap of negative and positive cases. The loss of pyloric wall stratification and echogenic muscularis propria is only seen in HPS.

Association of new sonographic features with outcome in neonates with necrotizing enterocolitis.

BACKGROUND: We have recently noted some sonographic features in necrotizing enterocolitis that have received little or no attention in the current literature. These include thickening of the mesentery, hyperechogenicity of intraluminal intestinal contents, abnormalities of the abdominal wall, and poor definition of the intestinal wall. It has been our impression that the above four sonographic findings are generally seen in neonates with more severe necrotizing enterocolitis and may be useful in predicting outcome. OBJECTIVES: The aim of this study is, firstly, to review a large series of neonates, known to have clinical NEC, to document how frequently the above four sonographic features occur in neonates with necrotizing enterocolitis and, secondly, to determine whether they are predictive of outcome. MATERIALS AND METHODS: We retrospectively analyzed the clinical, radiographic, sonographic, and surgical findings in neonates with necrotizing enterocolitis between 2018 and 2021. The neonates were categorized into two groups based on outcome. Group A included neonates with a favorable outcome defined as successful medical treatment with no surgical intervention. Group B included neonates with an unfavorable outcome defined as failed medical treatment requiring surgery (for acute complications or late strictures) or death because of necrotizing enterocolitis. The sonographic examinations were reviewed with attention to the features of mesenteric thickening, hyperechogenicity of intraluminal intestinal contents, abnormalities of the abdominal wall, and poor definition of the intestinal wall. We then determined the association of these four findings with the two groups. RESULTS: We included 102 neonates with clinical necrotizing enterocolitis: 45 in group A and 57 in group B. Neonates in group B were born at a significantly earlier gestational age (median 25 weeks, range 22-38 weeks) and had a significantly lower birth weight (median 715.5 g, range 404-3120 g) than those in group A (median age 32 weeks, range 22-39 weeks, p = 0.003; median weight 1190 g, range 480-4500 g, p = 0.002). The four sonographic features were present in both study groups but with different frequency. More importantly, all four were statistically significantly more frequently present in neonates in group B compared to group A: (i) mesenteric thickening, A = 31 (69%), B = 52 (91%), p = 0.007; (ii) hyperechogenicity of intestinal contents, A = 16 (36%), B = 41 (72%), p = 0.0005; (iii) abnormalities of the abdominal wall, A = 11 (24%), B = 35 (61%), p = 0.0004; and (iv) poor definition of the intestinal wall, A = 7 (16%), B = 25 (44%), p = 0.005. Furthermore, the proportion of neonates with more than two signs was greater in group B compared to group A (Z test, p < 0.0001, 95% CI = 0.22-0.61). CONCLUSION: The four new sonographic features described were found to occur statistically significantly more frequently in those neonates with an unfavorable outcome (group B) than in those with a favorable outcome (group A). The presence or absence of these signs should be included in the sonographic report to convey the radiologists concern regarding the severity of the disease in every neonate, suspected or known to have necrotizing enterocolitis, as the findings may impact further medical or surgical management.

Remote ischemic conditioning in necrotizing enterocolitis: study protocol of a multi-center phase II feasibility randomized controlled trial.

PURPOSE: Remote ischemic conditioning (RIC) is a maneuver involving brief cycles of ischemia reperfusion in an individual's limb. In the early stage of experimental NEC, RIC decreased intestinal injury and prolonged survival by counteracting the derangements in intestinal microcirculation. A single-center phase I study demonstrated that the performance of RIC was safe in neonates with NEC. The aim of this phase II RCT was to evaluate the safety and feasibility of RIC, to identify challenges in recruitment, retainment, and to inform a phase III RCT to evaluate efficacy. METHODS: RIC will be performed by trained research personnel and will consist of four cycles of limb ischemia (4-min via cuff inflation) followed by reperfusion (4-min via cuff deflation), repeated on two consecutive days post randomization. The primary endpoint of this RCT is feasibility and acceptability of recruiting and randomizing neonates within 24 h from NEC diagnosis as well as masking and completing the RIC intervention. RESULTS: We created a novel international consortium for this trial and created a consensus on the diagnostic criteria for NEC and protocol for the trial. The phase II multicenter-masked feasibility RCT will be conducted at 12 centers in Canada, USA, Sweden, The Netherlands, UK, and Spain. The inclusion criteria are: gestational age < 33 weeks, weight ≥ 750 g, NEC receiving medical treatment, and diagnosis established within previous 24 h. Neonates will be randomized to RIC (intervention) or no-RIC (control) and will continue to receive standard management of NEC. We expect to recruit and randomize 40% of eligible patients in the collaborating centers (78 patients; 39/arm) in 30 months. Bayesian methods will be used to combine uninformative prior distributions with the corresponding observed proportions from this trial to determine posterior distributions for parameters of feasibility. CONCLUSIONS: The newly established NEC consortium has generated novel data on NEC diagnosis and defined the feasibility parameters for the introduction of a novel treatment in NEC. This phase II RCT will inform a future phase III RCT to evaluate the efficacy and safety of RIC in early-stage NEC.

Ultra-high-frequency ultrasound of superficial and musculoskeletal structures in the pediatric population.

Because of its relatively low cost, lack of ionizing radiation and great versatility, US is considered the imaging modality of choice to evaluate a large variety of pediatric conditions. Imaging of superficial structures and small anatomical parts can be at times limited with standard US. Recent advances in technology yielded ultra-high-frequency US systems that are capable of scanning with frequencies as high as 70 MHz and resolutions of 30 µm. This technology, approved by the United States Food and Drug Administration, has not been widely used in the clinical setting. It has the potential to become a powerful diagnostic tool in clinical practice, especially in the evaluation of infants, given their inherent body habitus. Our main objective is to discuss the use of ultra-high-frequency US at a tertiary care center. This pictorial essay presents a gamut of pediatric pathologies pertaining to imaging of the soft tissues and the superficial and musculoskeletal structures. Our aim in this pictorial essay is to highlight and illustrate the role of ultra-high-frequency US in improving the depiction of common and less common pathologies. We think it also helps to gain a new understanding of the normal anatomy in the pediatric population and to display specific features not shown by standard US and, in certain cases, ones that lead to a change in diagnosis.

Intestinal ultrasonography in infants with moderate or severe hypoxic-ischemic encephalopathy receiving hypothermia.

BACKGROUND: Infants with hypoxic-ischemic encephalopathy (HIE) may develop multiorgan dysfunction, but assessment of intestinal involvement is imprecise and based on nonspecific clinical signs that may occur several days later. Ultrasound imaging has been described as a helpful tool in assessing intestinal involvement in many gastrointestinal disorders. OBJECTIVE: Describe abdominal ultrasonography findings in infants receiving therapeutic hypothermia and investigate its association with the severity of the hypoxic-ischemic insult and death. MATERIALS AND METHODS: Studies were performed within the first 36 h of life to assess intestinal appearance (normal bowel, bowel wall echogenicity and thickness, and sloughed mucosa), free fluid, peristalsis and intramural perfusion. These findings were compared between infants with moderate and severe encephalopathy. Ultrasound findings were also categorized in three major groups and compared with markers of severity of the hypoxic-ischemic insult and with mortality. RESULTS: Nineteen infants with moderate and 9 with severe HIE at admission were studied (17.7 ± 9.5 h of life). Major ultrasonography findings were increased bowel wall echogenicity (78%), free fluid (75%), decreased or absent peristalsis (50%) and sloughing of the intestinal mucosa (21%). Abnormal intestinal findings such as increased bowel wall echogenicity in all quadrants and presence of sloughed mucosa were associated with more severe hypoxic-ischemic insult. All 12 patients with normal bowel appearance or increased bowel wall echogenicity restricted to only one quadrant survived, whereas 7/15 (47%) patients with increased bowel wall echogenicity in all four quadrants died during hospitalization. The presence of sloughed mucosa was associated with increased mortality (P < 0.001). CONCLUSION: In infants receiving therapeutic hypothermia, a high prevalence of intestinal involvement was noted by using ultrasonographic assessment. An association between intestinal findings and severity of hypoxic-ischemic insult was observed. The presence of sloughed mucosa is a potential ultrasonographic sign of severity.

Neonatal hypoxic-ischemic injury: sonography and dynamic color Doppler sonography perfusion of the brain and abdomen with pathologic correlation.

OBJECTIVE: The purpose of this article is to describe the role of cerebral and abdominal sonography with color Doppler sonography, including assessment of multiorgan tissue perfusion, in neonates with hypoxic-ischemic injury. CONCLUSION: Bedside sonography and color Doppler sonography of the brain and abdominal organs can provide reliable and comprehensive information in asphyxiated neonates with hypoxic-ischemic injury. This article, which includes pathologic correlation, illustrates the major sonographic findings in this critical population.

Impact of Simulation Training on Radiology Resident Performance in Neonatal Head Ultrasound.

RATIONALE AND OBJECTIVES: The aim of this study was to determine whether resident performance in head ultrasound on neonates improves following brain phantom simulation training. MATERIALS AND METHODS: Ten junior radiology residents with at least one year of radiology training were divided into two equal groups. Both groups received a detailed head ultrasound protocol sheet and observed a technologist perform a head ultrasound on a neonatal patient at the beginning of their first pediatric radiology rotation. Both groups of residents also received teaching with a brain phantom model. Group A residents independently performed one head ultrasound exam, subsequently received phantom simulation training, and then performed a post-training head ultrasound exam. Group B residents received phantom simulation training prior to their first head ultrasound exam. Three pediatric radiologists independently and blindly reviewed the ultrasound images of each head ultrasound exam for proficiency of image acquisition using a validated scoring system. Scores of Group A residents prior to phantom training were compared to their scores after phantom training as well as to scores of Group B residents using simple linear regression. RESULTS: There was a statistically significant improvement in the performance of head ultrasound on neonates when comparing the same residents pre- and postphantom training (p = 0.003). Residents who initially trained with the phantom performed significantly better on their first head ultrasound examination on a neonate than those residents who did not (p = 0.005). CONCLUSION: Our novel head ultrasound phantom training model significantly improves radiology resident performance of head ultrasound on neonates and may, therefore, be beneficial for residency education.

Necrotizing enterocolitis: review of state-of-the-art imaging findings with pathologic correlation.

Plain abdominal radiography is the current standard imaging modality for evaluation of necrotizing enterocolitis (NEC). Sonography is still not routinely used for diagnosis and follow-up, as it is not widely recognized that it can provide information that is not provided by plain abdominal radiography and that may affect the management of NEC. Like plain abdominal radiography, sonography can depict intramural gas, portal venous gas, and free intraperitoneal gas. However, the major advantages of abdominal sonography over plain abdominal radiography are that it can depict intraabdominal fluid, bowel wall thickness, and bowel wall perfusion. Sonography may depict changes consistent with NEC when the plain abdominal radiographic findings are nonspecific and inconclusive. Thinning of the bowel wall and lack of perfusion at sonography are highly suggestive of nonviable bowel and may be seen before visualization of pneumoperitoneum at plain abdominal radiography. The mortality rate is higher after perforation; thus, earlier detection of severely ischemic or necrotic bowel loops, before perforation occurs, could potentially improve the morbidity and mortality in NEC. The information provided by sonography allows a more complete understanding of the state of the bowel in patients with NEC and may thus make management decisions easier and potentially change outcome.

Magnetic resonance imaging of pelvis and hips in infants, children, and adolescents: a pictorial review.

Due to its superior tissue resolution, magnetic resonance imaging has become the modality of choice for assessing pathologies of soft tissues, joints, cartilage, and bone marrow. This is also true in the pediatric population. This article reviews magnetic resonance imaging appearances and techniques for a variety of congenital abnormalities and acquired conditions including posttraumatic, infectious, inflammatory, ischemic, metabolic, benign, and malignant processes.

Magnetic resonance imaging of the urinary tract in the fetal and pediatric population.

Magnetic resonance imaging (MRI) has become an excellent modality for the assessment of renal pathologies in children; its multiplanar capability and soft-tissue contrast resolution allows for exquisite demonstration of the renal anatomy and its abnormalities. In this article, we illustrate and discuss MRI techniques and findings of the most commonly seen renal anomalies, including congenital, inflammatory, neoplastic, posttransplant, and miscellaneous conditions.

Intraventricular hemorrhage in term neonates with hypoxic-ischemic encephalopathy: a comparison study between neonates treated with and without hypothermia.

BACKGROUND: To retrospectively determine the prevalence of intraventricular hemorrhage (IVH) in term neonates with hypoxic-ischemic encephalopathy (HIE) using head ultrasound (HUS) and MRI, and to compare the incidence of IVH in term babies with HIE treated by therapeutic hypothermia versus those managed conventionally. METHODS: A total of 61 term neonates from two institutions were diagnosed with HIE shortly after birth. Thirty infants from one institution were treated with whole body hypothermia. These infants had to satisfy the entry criteria for the neonatal hypothermia protocol of the institution. Thirty-one neonates underwent conventional treatment at the second institution. At that time, hypothermia was not yet a standard of care at that institution. All the neonates underwent HUS in their first 23 days of life. The 54 survivors also underwent MRI. The imaging studies were all reviewed for IVH. RESULTS: Amongst the 30 babies, who received whole body hypothermia, there were 18 males and 12 females, the mean birth weight was 3.5 kg (2.5 to 5.2 kg), and the HUS study was performed within 14.8 to 41 hours of life. The group of 31 infants treated conventionally was comprised of 12 boys and 19 girls, the infants had an average birth weight of 3.3 kg (2.3 to 4.2 kg), and they underwent HUS 1 to 23 days after birth, with only five children being older than 1 week at the time of the imaging studies. Four of the 61 infants (7%) were diagnosed with IVH on HUS. Three were confirmed with MRI. The fourth case showed a bilateral enlarged choroid plexus on HUS, but IVH could not be confirmed with MRI, as the infant did not survive. In the group of neonates treated with hypothermia, there were three cases (10%) of IVH, whereas in the group managed conventionally, IVH occurred in one infant (3%). CONCLUSIONS: Our study shows that IVH remains uncommon in term infants with HIE. IVH was more prevalent in the group treated with hypothermia.

Basal ganglia perfusion using dynamic color Doppler sonography in infants with hypoxic ischemic encephalopathy receiving therapeutic hypothermia: a pilot study.

BACKGROUND: The objective of this study was to evaluate the cerebral perfusion of the basal ganglia in infants with hypoxic-ischemic encephalopathy (HIE) receiving hypothermia using dynamic color Doppler sonography (CDS) and investigate for any correlation between these measurements and survival. METHODS: Head ultrasound (HUS) was performed with a 9S4 MHz sector transducer in HIE infants submitted to hypothermia as part of their routine care. Measurements of cerebral perfusion intensity (CPI) with an 11LW4 MHz linear array transducer were performed to obtain static images and DICOM color Doppler videos of the blood flow in the basal ganglia area. Clinical and radiological data were evaluated retrospectively. The video images were analyzed by two radiologists using dedicated software, which allows automatic quantification of color Doppler data from a region of interest (ROI) by dynamically assessing color pixels and flow velocity during the heart cycle. CPI is expressed in cm/sec and is calculated by multiplying the mean velocity of all pixels divided by the area of the ROI. Three videos of 3 seconds each were obtained of the ROI, in the coronal plane, and used to calculate the CPI. Data are presented as mean ± SEM or median (quartiles). RESULTS: A total of 28 infants were included in this study: 16 male, 12 female. HUS was performed within the first 48 hours of therapeutic hypothermia treatment. CPI values were significantly higher in the seven non-survivors when compared to survivors (0.226±0.221 vs. 0.111±0.082 cm/sec; P=0.02). CONCLUSIONS: Increased perfusion intensity of the basal ganglia area within the first 48 of therapeutic hypothermia treatment was associated with poor outcome in neonates with HIE.

Magnetic resonance imaging of congenital, inflammatory, and infectious soft-tissue lesions in children.

Magnetic resonance imaging has the advantages of multiplanar capability and high degree of tissue differentiation. It is useful for assessing the extent of soft-tissue abnormalities, such as vascular malformations, inflammatory and infectious processes, muscle disorders, and limb hypertrophy. Magnetic resonance imaging is sensitive to the presence of water and edema and is a good indicator for early diagnosis of inflammation and its level of activity. Fat-saturation techniques, including T2-weighted sequences and inversion recovery imaging, optimize diagnostic accuracy. T1-weighted images are good at defining the distribution and proportion of fat in the body, so they are useful in evaluating syndromes of the limbs, including vascular malformations, as well as lipoatrophy-lipodystrophy conditions. Magnetic resonance imaging provides guidance for efficient tissue biopsy. It allows comprehensive pretherapeutic assessment of soft-tissue vascular anomalies. It constitutes a good modality for following up the natural history of soft-tissue disorders during childhood.

Imaging of low back pain in children and adolescents.

In children with low back pain (LBP), a specific cause is often identified. LBP has a relatively high prevalence during school years. However, only a minority of the children suffering from LBP seek medical attention. Protracted back pain in childhood is a serious condition that should be thoroughly investigated. This article is a systematic review of the intrinsic causes of LBP. Imaging modalities are discussed, with emphasis on magnetic resonance imaging. We have divided the intrinsic causes of LBP into four main groups: mechanical, developmental, infectious/inflammatory, and neoplastic. Disk protrusion is prevalent in young athletes. Spondylolysis and spondylolisthesis are the most common causes of chronic LBP in children. Thoracic or thoracolumbar Scheuermann disease causes kyphosis while a lumbar localization is more painful. Childhood diskitis is associated with fever and leukocytosis. Spinal inflammatory arthritides in children include juvenile rheumatoid arthritis, the juvenile spondyloarthropathies, and SAPHO syndrome, where spine as well as sacroiliac joint changes may be seen. Cysts, tumors, tumor-like lesions, and metastases are infrequent causes of back pain in children. Several of these conditions are described and illustrated in this review of LBP in children and adolescents.

Hepatobiliary tumors.

The investigation of hepatobiliary tumors, in the pediatric population, usually begins with an ultrasonographic (US) examination. It is readily available without ionizing radiation and does not need sedation. Therefore US is an outstanding imaging modality for screening and follow-up. Doppler and color Doppler interrogation are part of the examination to assess vascularity of the lesions and vascular anatomy. Magnetic resonance imaging is a comprehensive imaging modality with multiplanar capability to assess the liver parenchyma, gallbladder, and biliary tree and is free of ionizing radiation. This article highlights the current status of imaging of the most common hepatobiliary tumors in children.

Magnetic resonance imaging of the liver and biliary tree in children.

Magnetic resonance imaging (MRI) is a great modality for the assessment of the liver and biliary tree in the pediatric population. In this review, we illustrate and discuss MRI technique and a variety of congenital abnormalities and acquired conditions including infectious, inflammatory, metabolic, benign, and malignant processes. The role of magnetic resonance angiography and magnetic resonance venography is discussed in hepatic tumors and portal hypertension. Magnetic resonance cholangiopancreatography protocol is also addressed. Although ultrasound remains a screening tool and computer tomography is readily available, MRI accurately depicts the pathology, leading to a better understanding of the disease process with optimal patient management and follow-up, without the use of ionizing radiation.