Pediatric chest wall masses: spectrum of benign findings on ultrasound.

A palpable finding along the chest wall is a frequent indication for pediatric US. Accurate identification of benign lesions can reassure families and appropriately triage children who need follow-up, cross-sectional imaging, or biopsy. In this pictorial essay, we review chest wall anatomy, illustrate US techniques and discuss key US imaging features of common benign lesions and normal variants.

Longitudinal assessment of vascular calcification in generalized arterial calcification of infancy.

BACKGROUND: Generalized arterial calcification of infancy (GACI), also known as idiopathic infantile arterial calcification, is a very uncommon genetic disorder characterized by calcifications and stenoses of large- and medium-size arteries that can lead to end-organ damage. OBJECTIVE: To describe changes in imaging findings in 10 children with GACI at a single institution from 2010 to 2021. MATERIALS AND METHODS: In this retrospective study we reviewed initial and follow-up body imaging in children with genetic confirmation of GACI at our hospital. All initial images were analyzed for the presence and distribution of arterial calcifications, stenoses and wall thickening/irregularity within the chest, abdomen and pelvis. We compared available follow-up studies to the initial imaging findings. We extracted clinical information including prenatal and postnatal treatment from the children's medical records. RESULTS: We evaluated 10 children (five boys) with a diagnosis of GACI. Median age at first body imaging was 8 days (range: 1 day to 5 years). Six children were identified prenatally and four postnatally. Postnatal presentation included cardiac failure, seizures and hypertension. Images in newborns (n = 8) most commonly showed diffuse arterial calcifications (6/8; 75%), while stenoses were less common (2/8; 25%) during this period. Two children were diagnosed after the neonatal period - one in infancy and one during childhood. In total, half the children (5/10; 50%) had arterial stenoses - three cases visualized at first imaging and two identified on follow-up images during infancy. Stenoses had completely resolved in one child (1/5; 20%) at last follow-up. Eight children received prenatal or postnatal treatment or both. All children who received both prenatal and postnatal treatment (n = 4) had completely resolved calcifications at last follow-up. CONCLUSION: Children with GACI might have characteristic vascular calcifications at birth that raise the suspicion of this disease. Arterial calcifications decrease or disappear spontaneously or after treatment, but arterial stenoses usually persist. Calcifications and arterial stenoses can be easily identified and followed with non-contrast CT and CT angiography.

MRI Findings of Infectious Sacroiliitis in Children: Are There Age-Dependent Differences?

OBJECTIVE. The purpose of this study was to investigate the prevalence of various MRI findings of infectious sacroiliitis in children and with respect to age. MATERIALS AND METHODS. This institutional review board-approved, HIPAA-compliant retrospective study included children with infectious sacroiliitis who underwent MRI examination between December 1, 2002, and September 30, 2018. Two radiologists blinded to the clinical outcome reviewed each MRI examination to determine the presence or absence of periarticular marrow edema, erosions, capsular bulge, extracapsular edema, and soft-tissue abscess. If available, pelvic radiographs were retrospectively reviewed by a third radiologist. Mann-Whitney U, chi-square, and Fisher exact tests were used to compare MRI findings between younger and older children. RESULTS. The study included 40 children (19 boys and 21 girls; mean age, 8.6 ± 6.2 [SD] years). Sixteen children presented at or below 5 years of age (mean age, 1.7 ± 1.4 years) and 24 children presented at or above 8 years of age (mean age, 13.3 + 2.6 years). Periarticular marrow edema and anterior extracapsular edema were present in all children. Posterior extracapsular edema (p = 0.01) was statistically significantly more common in younger children when compared with older children. There was no significant difference in the presence of erosions (p = 0.60), capsule bulge (p = 0.63), or abscess (p = 0.34) between younger and older children. Pelvic radiographs (n = 28; obtained 1.6 days ± 1.7 from MRI) allowed the correct identification of the abnormal joint in only 50% of the studies. CONCLUSION. MRI findings of infectious sacroiliitis are common in children of all ages with posterior extracapsular edema statistically significantly more prevalent in younger children.

Imaging of developmental dysplasia of the hip: ultrasound, radiography and magnetic resonance imaging.

Developmental dysplasia of the hip (DDH) describes a broad spectrum of developmental abnormalities of the hip joint that are traditionally diagnosed during infancy. Because the development of the hip joint is a dynamic process, optimal treatment depends not only on the severity of the dysplasia, but also on the age of the child. Various imaging modalities are routinely used to confirm suspected diagnosis, to assess severity, and to monitor treatment response. For infants younger than 4 months, screening hip ultrasound (US) is recommended only for those with risk factors, equivocal or positive exam findings, whereas for infants older than 4-6 months, pelvis radiography is preferred. Following surgical hip reduction, magnetic resonance (MR) imaging is preferred over computed tomography (CT) because MR can not only confirm concentric hip joint reduction, but also identify the presence of soft-tissue barriers to reduction and any unexpected postoperative complications. The routine use of contrast-enhanced MR remains controversial because of the relative paucity of well-powered and validated literature. The main objectives of this article are to review the normal and abnormal developmental anatomy of the hip joint, to discuss the rationale behind the current recommendations on the most appropriate selection of imaging modalities for screening and diagnosis, and to review routine and uncommon findings that can be identified on post-reduction MR, using an evidence-based approach. A basic understanding of the physiology and the pathophysiology can help ensure the selection of optimal imaging modality and reduce equivocal diagnoses that can lead to unnecessary treatment.