Contrast-Enhanced Ultrasound of the Chest in Children and Adolescents: A Pilot Study for Assessment of Added Diagnostic Value.

OBJECTIVES: To determine the added diagnostic value of contrast-enhanced ultrasound (CEUS) in pediatric chest abnormalities by comparing interpretation of CEUS studies and confidence level to conventional US studies. METHODS: CEUS studies in patients with a variety of clinically suspected chest abnormalities performed between 2016 and 2020 were reviewed and compared to same-day conventional US studies. Examinations were independently interpreted by 4 radiologists blinded to clinical and other imaging data. Rater confidence was classified as low, moderate, or high. Diagnostic accuracy was determined by comparing image interpretation to patient outcome as the ground truth. Interobserver agreement was also assessed. RESULTS: Sixteen patients (10 male) with 18 CEUS studies were included. Median rater agreement with ground truth was significantly higher for CEUS (100%) than conventional US (50%; P = .004). Median rater confidence was high (3.0) for CEUS, and low-moderate (1.5) for conventional US (P < .001). CEUS sensitivity (54.6-81.8%) and specificity (63.4-100.0%) were greater than conventional US (45.5-72.7% and 12.5-63.5%, respectively). CEUS false positives (0-4) and false negatives (2-5) were fewer than conventional US (4-7 and 3-6, respectively). Except for one rater pair where agreement was substantial (κ = .78, P < .01), inter-rater agreement for CEUS for all other rater pairs was nonsignificant (κ = .25-0.51, P ≥ .07). Agreement for conventional US was moderate and statistically significant for 3 rater pairs (κ = .55-0.78) and nonsignificant for the remaining 3 rater pairs (P ≥ .06). CONCLUSIONS: CEUS adds diagnostic value to the assessment of a variety of chest abnormalities. The data support further evaluation of the role of CEUS as a non-invasive, problem-solving technique in children.

Verrucous Venous Malformation-Subcutaneous Variant.

BACKGROUND: Verrucous venous malformation (VVM), previously called "verrucous hemangioma," typically involves the dermis and the subcutaneous fat. We have encountered patients with VVM confined to the hypodermis. MATERIALS AND METHODS: During a nearly 20-year period, 13 patients, aged 2-17 years, presented with a subcutaneous mass in the limb without clinically obvious epidermal alterations. Consequently, operative excisions did not include the skin. RESULTS: Histopathologically, the specimens were composed of blood-filled channels with morphologic characteristics of capillaries and veins that infiltrated adipose tissue. Aggregates often formed nodules with variable fibrosis and a component of large and radially oriented vessels. A diagnosis of VVM was supported by endothelial immunopositivity for GLUT-1 (25%-75% immunopositive channels in 16/16 specimens); D2-40 (1%-25% channels in 14/15 specimens); and Prox-1 (1%-50% of channels in 14/16 specimens). A MAP3K3 mutation was identified by droplet digital PCR in 3 of the 6 specimens. CONCLUSIONS: Diagnosis of VVM in this uncommon location is challenging because of absence of epidermal changes and lack of dermal involvement. Imaging is not pathognomonic, and mimickers are many. Appropriate immunohistochemical stains and molecular analysis contribute to the correct diagnosis.

Translational research in pediatric contrast-enhanced ultrasound.

The role of contrast-enhanced ultrasound (CEUS) imaging is being widely explored by various groups for its use in the pediatric population. Clinical implementation of new diagnostic or therapeutic techniques requires extensive and meticulous preclinical testing and evaluation. The impact of CEUS will be determined in part by the extent to which studies are oriented specifically toward a pediatric population. Rather than simply applying principles and techniques used in the adult population, these studies are expected to advance and augment preexisting knowledge with pediatric-specific information. To further develop this imaging modality for use in children, pediatric-focused preclinical research is essential. In this paper we describe the development and implementation of the pediatric-specific preclinical animal and phantom models that are being used to evaluate CEUS with the goal of clinical translation to children.

Contrast-enhanced ultrasound of blunt abdominal trauma in children.

Trauma is the leading cause of morbidity and mortality in children, and rapid identification of organ injury is essential for successful treatment. Contrast-enhanced ultrasound (CEUS) is an appealing alternative to contrast-enhanced CT in the evaluation of children with blunt abdominal trauma, mainly with respect to the potential reduction of population-level exposure to ionizing radiation. This is particularly important in children, who are more vulnerable to the hazards of ionizing radiation than adults. CEUS is useful in hemodynamically stable children with isolated blunt low- to moderate-energy abdominal trauma to rule out solid organ injuries. It can also be used to further evaluate uncertain contrast-enhanced CT findings, as well as in the follow-up of conservatively managed traumatic injuries. CEUS can be used to detect abnormalities that are not apparent by conventional US, including infarcts, pseudoaneurysms and active bleeding. In this article we present the current experience from the use of CEUS for the evaluation of pediatric blunt abdominal trauma, emphasizing the examination technique and interpretation of major abnormalities associated with injuries in the liver, spleen, kidneys, adrenal glands, pancreas and testes. We also discuss the limitations of the technique and offer a review of the major literature on this topic in children, including an extrapolation of experience from adults.

Contrast-enhanced ultrasound of the kidneys and adrenals in children.

Pediatric applications of contrast-enhanced ultrasound (CEUS) are growing. Evaluation of the kidneys and adrenal glands in children using intravenous administration of US contrast agents, however, is still an off-label indication. Pediatric CEUS applications for kidneys are similar to those in adults, including ischemic disorders, pseudo- versus real tumors, indeterminate lesions, complex cystic lesions, complicated pyelonephritis, and abscesses. CEUS applications for evaluation of adrenal glands in children are limited, mainly focusing on the assessment and follow-up of adrenal trauma and the differentiation between an adrenal hemorrhage and a mass. This review addresses the current experience in pediatric CEUS of the kidneys and adrenal glands. By extrapolating the established knowledge for US contrast evaluations in the adult kidney to the pediatric context we can note opportunities for CEUS clinical use in children.

Contrast-enhanced ultrasound of benign and malignant liver lesions in children.

Contrast-enhanced ultrasound (CEUS) is increasingly being used in children. One of the most common referrals for CEUS performance is characterization of indeterminate focal liver lesions and follow-up of known liver lesions. In this setting, CEUS is performed with intravenous administration of ultrasound contrast agents (UCAs). When injected into a vein, UCA microbubbles remain confined within the vascular network until they dissipate. Therefore, visualization of UCA within the tissues and lesions corresponds to true blood flow. CEUS enables continuous, real-time observation of the enhancement pattern of a focal liver lesion, allowing in most cases for a definite diagnosis and obviating the need for further cross-sectional imaging or other interventional procedures. The recent approval of Lumason (Bracco Diagnostics, Monroe Township, NJ) for pediatric liver CEUS applications has spurred the widespread use of CEUS. In this review article we describe the role of CEUS in pediatric liver applications, focusing on the examination technique and interpretation of main imaging findings of the most commonly encountered benign and malignant focal liver lesions. We also compare the diagnostic performance of CEUS with other imaging modalities for accurate characterization of focal liver lesions.

Contrast-Enhanced Colosonography for the Evaluation of Children With an Imperforate Anus.

This case series describes a novel method for showing the preoperative anatomy of children with anorectal malformations using ultrasound contrast, which we have termed "contrast-enhanced colosonography (ceCS)." Six patients with anorectal malformations without a perineal fistula were studied both by fluoroscopic distal colostography and ceCS, and their results were confirmed surgically. Contrast-enhanced CS precisely showed the complex anatomic relationships in all cases. Compared to traditional fluoroscopic studies, ceCS has the benefit of no associated ionizing radiation and thus is safer for children.

Pediatric contrast-enhanced ultrasound in the United States: a survey by the Contrast-Enhanced Ultrasound Task Force of the Society for Pediatric Radiology.

BACKGROUND: The United States Food and Drug Administration (FDA) recently approved an ultrasound (US) contrast agent for intravenous and intravesical administration in children. OBJECTIVE: Survey the usage, interest in and barriers for contrast-enhanced US among pediatric radiologists. MATERIALS AND METHODS: The Contrast-Enhanced Ultrasound Task Force of the Society for Pediatric Radiology (SPR) surveyed the membership of the SPR in January 2017 regarding their current use and opinions about contrast-enhanced US in pediatrics. RESULTS: The majority (51.1%, 166) of the 325 respondents (26.7% of 1,218) practice in either a university- or academic affiliated group. The most widely used US contrast agent was Lumason® 52.3% (23/44). While lack of expertise and training were reported barriers, all respondents who are not currently using US contrast agents are considering future use. CONCLUSION: Interest in pediatric contrast US is very high. Education and training are needed to support members who plan to adopt contrast US into practice.

Imaging in the diagnosis of pediatric urolithiasis.

Pediatric urolithiasis is an important and increasingly prevalent cause of pediatric morbidity and hospital admission. Ultrasound (US) is the recommended primary imaging modality for suspected urolithiasis in children. There is, however, widespread use of CT as a first-line study for abdominal pain in many institutions involved in pediatric care. The objective of this review is to outline state-of-the-art imaging modalities and methods for diagnosing urolithiasis in children. The pediatric radiologist plays a key role in ensuring that the appropriate imaging modality is performed in the setting of suspected pediatric urolithiasis. Our proposed imaging algorithm starts with US, and describes the optimal technique and indications for the use of CT. We emphasize the importance of improved communication with a greater collaborative approach between pediatric and general radiology departments so children undergo the appropriate imaging evaluation.

Sperm Retrieval in Adolescents and Young Adults with Klinefelter Syndrome: A Prospective, Pilot Study.

OBJECTIVE: To assess sperm retrieval rates in adolescents and young adults with Klinefelter syndrome, with the ultimate goal of improving fertility in this population. Secondary aims were to evaluate other clinical characteristics of the cohort and identify predictors of sperm retrieval. STUDY DESIGN: Patients 12-25 years of age with Klinefelter syndrome (47,XXY) were recruited at the Boston Children's Hospital. Physical examination, biochemical evaluation, scrotal ultrasonography, and semen analysis were performed. Neurocognitive data were collected. Microdissection sperm extraction (unilateral micro-testicular sperm extraction) was offered to individuals with no sperm in their ejaculates. Given the small sample size, analysis was primarily descriptive. RESULTS: Fifteen patients were enrolled. None had sperm in their ejaculates. Ten patients underwent unilateral micro-testicular sperm extraction. Sperm retrieval rate was 50%. From a neurocognitive standpoint, subjects reported problems with peers, conduct, and overall difficulties. Incidentally, one-third of the patients were found to have testicular microlithiasis and 17% of subjects with renal ultrasound imaging had bilateral renal medullary nephrocalcinosis. CONCLUSIONS: This pilot study suggests that sperm retrieval rates in adolescents and young adults with Klinefelter syndrome are comparable with those reported in older men. However, larger studies are needed to confirm our findings. The clinical significance of the scrotal and renal ultrasound findings merits further investigation. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01817296.

Intrarenal Reflux: Diagnosis at Contrast-Enhanced Voiding Urosonography.

Vesicoureteral reflux (VUR) is a childhood condition that is usually diagnosed by fluoroscopic voiding cystourethrography (VCUG). Intrarenal reflux (IRR) of infected urine is believed to play an important role in the pathogenesis of reflux-associated pyelonephritis and subsequent parenchymal scarring and is traditionally depicted by fluoroscopic VCUG. This case series describes the phenomenon of IRR occurring in association with VUR in 4 children as depicted by contrast-enhanced voiding urosonography. The ability of contrast-enhanced voiding urosonography to show IRR when it occurs in conjunction with VUR compares favorably to that of fluoroscopic VCUG.

Residual intravesical iodinated contrast: a potential cause of false-negative reflux study at contrast-enhanced voiding urosonography.

A 9-month-old girl underwent conventional cyclic voiding cystourethrography (VCUG) followed immediately by cyclic contrast-enhanced voiding urosonography (ceVUS). Although the VCUG showed unilateral grade II reflux, the ceVUS showed no reflux. Images from the ceVUS showed posterior dependent layering of the denser iodinated contrast in the bladder. This layering likely prevented reflux of US microbubbles resulting in a false-negative ceVUS. To our knowledge, this potential pitfall has not yet been reported.

US of the pediatric female pelvis.

This review presents the normal and pathologic development of the gonads and genitourinary tract and addresses the role of ultrasonography in the diagnosis and management of gynecologic disorders of the pediatric pelvis, including ambiguous genitalia, prepubertal bleeding, primary amenorrhea, pelvic mass, and pelvic pain.