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.

Comparison of Contrast-enhanced Ultrasound and Contrast-enhanced Magnetic Resonance Imaging in the Assessment of Infant Hip Perfusion and Prediction of Proximal Femoral Growth Disturbance Following Closed and Open Reduction for Developmental Dysplasia of the Hip: A Preliminary Study.

OBJECTIVE: Proximal femoral growth disturbance (PFGD) is a significant complication associated with surgical treatment of infant hip dislocation. Contrast-enhanced magnetic resonance imaging (CEMRI) has been utilized to assess perfusion in these hips and avoid PFGD. Contrast-enhanced ultrasound (CEUS) is an imaging technique utilized to evaluate perfusion in other organs. The aims of this study were to compare perfusion of dysplastic infant hips with CEUS and CEMRI after surgical treatment and to determine whether CEUS was as effective as CEMRI at predicting PFGD. METHODS: A retrospective analysis of patients undergoing closed or open reduction for infant hip dislocation between 2012 and 2019 was performed. All patients underwent intraoperative CEUS and postoperative CEMRI to assess femoral epiphyseal perfusion using intravenous contrast. Perfusion status was rated as normal, partially decreased, or globally decreased in both modalities. Agreement in perfusion status between CEUS and CEMRI was assessed. Patients were followed for a minimum of 2 years postoperatively and assessed for PFGD. RESULTS: Eighteen patients (28% males) underwent closed or open reduction at an average age of 8 months (3 to 16 mo). The agreement in perfusion status between CEUS and CEMRI was substantial (α = 0.74). Patients were followed for a median of 3 years. PFGD developed in 3 hips (17%). For the detection of PFGD, both imaging modalities performed very well and with no difference in the diagnostic utility of CEUS compared with CEMRI. Considering normal perfusion alone the accuracy, sensitivity, and specificity for CEUS were 83%, 100%, and 80%, and for CEMRI were 78%, 100%, and 73%, respectively. Considering global decreased perfusion alone, the accuracy, sensitivity, and specificity for CEUS were 94%, 67%, and 100%, and for CEMRI were 89%, 67%, and 93%, respectively. CONCLUSIONS: CEUS is a viable intraoperative method to assess infant hip perfusion. This pilot study appears to be comparable to CEMRI at visualizing perfusion of infant hips and as good or better in predicting PFGD after hip reduction. Prospective studies of this imaging technique should be performed to confirm the findings of this retrospective review. LEVEL OF EVIDENCE: Level II-development diagnostic criteria on the basis of consecutive patients (with generally preferred standard).

Accuracy of contrast-enhanced voiding urosonography using Optison™ for diagnosis of vesicoureteral reflux in children.

BACKGROUND: There is limited quality of evidence regarding the accuracy of contrast-enhanced voiding urosonography (ceVUS) for diagnosis of vesicoureteral reflux (VUR) compared to fluoroscopic voiding cystourethrography (VCUG), and minimal data on the use of the ultrasound contrast agent Optison™ for this purpose. OBJECTIVE: To compare the accuracy of ceVUS using Optison™ to VCUG, and to assess inter-rater agreement regarding presence and grading of VUR. STUDY DESIGN: In this retrospective investigation, all sequential ceVUS with Optison™ and VCUG studies performed in children between 2014 and 2017 were reviewed. Two raters independently graded all ceVUS studies using a 5-point scale. CeVUS sensitivity and specificity were estimated separately for each rater using the VCUG report as the ground truth for presence and degree of VUR. Logistic and ordinary linear regression models assessed rater-report agreement and inter-rater agreement for each kidney, Optison™ dose, and referral diagnosis. RESULTS: 97 children (51 females) with 101 paired studies were included. Sensitivity and specificity of ceVUS for VUR detection were identical for both raters: right kidney 75%/90.9%; left kidney 85.7%/78.9% (Figure). There was no statistically significant difference in disagreement between raters and the VCUG report for the right or left kidney. Inter-rater agreement on ceVUS grading was 90% and 88% for right and left kidneys, respectively. There was a significant negative association between fetal hydronephrosis vs urinary tract infection and disagreement between Rater 2 and the VCUG report for the left kidney. There were no other significant associations with respect to either kidney, Optison™ dose, or referral diagnosis. DISCUSSION: Our study showed that detection of VUR with ceVUS and Optison™ is comparable to fluoroscopic VCUG. Based on the VCUG reports, the incidence of VUR in our patient population was substantially lower than in the meta-analysis of Chua et al. and in the study of Kim et al. The explanation for the large discrepancy in VUR incidence may reflect differences in the patient populations, and in our reporting of VUR with respect to kidney number rather than to pelviureteral units. Study limitations include its retrospective nature and potential bias in terms of patient selection. Since VUR is an intermittent phenomenon, sequential rather than simultaneous performance of the ceVUS and fluoroscopic studies might have influenced VUR detection. CONCLUSION: A blinded comparison of ceVUS performed with Optison™ to fluoroscopic VCUG showed moderate-good sensitivity and specificity for diagnosis of VUR.

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.

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.

Clinical outcome of pediatric and young adult subclinical varicoceles: a single-institution experience.

Subclinical varicocele represents an abnormality of veins of the pampiniform plexus on scrotal ultrasound (US) without a clinically palpable varicocele. Its significance remains unclear. While guidelines do not recommend surgical intervention, clinical management is variable. As there is limited information on long-term outcome of subclinical varicoceles due to challenges in diagnosis and management, we performed a single-institution, retrospective review of patients from October 1999 to October 2014 with subclinical varicocele and with available US studies reviewed by a single radiologist. Subclinical varicocele was defined as dilation of the pampiniform venous plexus on US involving ≥2 vessels with diameter >2.5 mm, without clinical varicocele on physical examination or prior inguinal surgery. Thirty-six of 98 patients identified were confirmed as having a subclinical varicocele and analyzed. The mean age at initial visit was 15.5 years, with a mean follow-up of 26.5 months. The majority were right-sided (69.4%, n = 25), usually with a contralateral clinical varicocele. Testicular asymmetry (>20% volume difference of the affected side by testicular atrophy index formula) was assessed in 9 patients with unilateral subclinical varicocele without contralateral clinical or subclinical varicocele and observed in 1 patient. Of 17 patients with follow-up, 3 (17.6%) progressed to clinical varicocele without asymmetric testicular volume, as most remained subclinical or resolved without surgery. In our experience, subclinical varicoceles appeared unlikely to progress to clinical varicoceles, to affect testicular volume, or to lead to surgery. Although our study is limited in numbers and follow-up, this information may aid clinical management strategies and guide future prospective studies.

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.

Contrast enhanced colostography: New applications in preoperative evaluation of anorectal malformations.

INTRODUCTION: Understanding details of anatomic relationships between the colon and surrounding structures is a critical piece of preoperative planning prior to surgical repair of anorectal malformations (ARMs). Traditional imaging techniques involve ionizing radiation, distention of the rectum with supraphysiologic intraluminal pressures, and sometimes require sedation. Recent developments in the field of contrast agents have allowed the emergence of an ultrasound-based technique that can avoid these requirements while continuing to provide high resolution structural information in three dimensions. METHODS: Fourteen children (13 male, 1 female, age 1-11 months) with ARMs underwent contrast enhanced colostography (ceCS) in addition to traditional preoperative imaging techniques to delineate anatomic relationships of pelvic structures. RESULTS: ceCS and traditional imaging yielded concordant anatomic information, including structural relationships and fistulous connections, in 10/14 patients (71%). ceCS detected fistulous connection in 2/13 patients (15%) that were not seen by traditional imaging. Ultrasonography failed to detect the fistulous connection in one patient. CONCLUSIONS: ceCS is a safe, effective and flexible method for defining important structural information in ARM patients. When compared with traditional methods, it provided equivalent or superior results 93% of the time and bears consideration as a standard tool in preoperative planning for this population. TYPE OF STUDY: Retrospective Comparative Study. LEVEL OF EVIDENCE: Level III.

Contrast-enhanced Ultrasound-State of the Art in North America: Society of Radiologists in Ultrasound White Paper.

On October 24, 2017, in Chicago, the Society of Radiologists in Ultrasound convened a panel of specialists in contrast-enhanced ultrasound (CEUS) to arrive at a white paper regarding the use of CEUS in noncardiac applications in North America. Recommendations are based on analysis of the current literature and common practice strategies. They represent a reasonable approach to introduce the advantages of this safe and noninvasive technique for the benefit of our patients. Characterization of liver nodules with CEUS, as the approval indication worldwide, is the major focus of this endeavor. In addition, many off label uses are reviewed and literature supporting these indications provided.Key Points(1) Contrast-enhanced ultrasound (CEUS) allows cross-sectional imaging of the liver, kidneys and multiple other solid and hollow viscera, providing excellent characterization of identified focal mass lesions.(2) Performed with the injection of a microbubble contrast agent, CEUS provides a safe and readily available imaging technique which requires no ionizing radiation, making it appropriate for use in all ages, in those with renal insufficiency and when a portable examination is needed.(3) The CEUS can be considered in abdominal imaging whenever blood flow information is of value to diagnosis.(4) Dynamic real-time acquisition and the use of a purely intravascular contrast agent are the 2 most essential technical aspects of CEUS imaging which distinguish it from both computed tomography and magnetic resonance scan.

Contrast -Enhanced Ultrasound: State of the Art in North America.

The Society of Radiologists in Ultrasound convened a panel of specialists in contrast-enhanced ultrasound (CEUS) to produce a white paper on noncardiac CEUS in North America. The panel met in Chicago, Illinois, on October 24 and 25, 2017. The recommendations are based on analysis of current literature and common practice strategies and are thought to represent a reasonable approach to introduce the advantages of this safe and noninvasive technique for the benefit of our patients. Characterization of liver nodules, and pediatric vascular and intravesicular applications comprise the approved indications for CEUS in the United States. They, along with the very successful off-label use of CEUS for the kidney, are included in this publication.Other off-label uses are presented with emphasis on their value and literature support in the online version.

Supernumerary intrathoracic rib, a rare congenital anomaly: Case report and review of the literature.

A 17-year-old female who presented with cough, chest pain, dyspnea, and hemoptysis was found to have an intrathoracic rib. Patients who are diagnosed with intrathoracic ribs are most often asymptomatic and should undergo limited diagnostic workup. Intrathoracic ribs are rare congenital anomalies incidentally identified after chest radiography performed for another indication, as is the case with this patient. In this case, further evaluation was necessary due to persistent symptoms. Here, we used contrast-enhanced ultrasound after chest radiography and computed tomography to further evaluate the fatty intrathoracic mass and exclude vascular features suggestive of a tumor.

Case series: Comparison of contrast-enhanced genitosonography (ceGS) to fluoroscopy and cone-beam computed tomography in patients with urogenital sinus and the cloacal malformation.

In this case series, contrast enhanced genitosonography is compared to genitography performed using fluoroscopy and cone-beam computed tomography in patients with urogenital sinus and the cloacal malformation. The method of contrast enhanced genitosonography is described, including contrast preparation, contrast administration, ultrasound imaging approaches, as well as the benefits and potential pitfalls of this technique compared to fluoroscopy and computed tomography.