Management of pediatric foot deformities: an imaging review.

Abnormalities of foot alignment can be a cause of significant morbidity in children, and some require complex surgical intervention to improve functionality and decrease pain. Imaging plays a key role in management decisions. We address some of the most common surgical strategies for selected diagnoses including pes planus, congenital vertical talus, pes cavus, and clubfoot, with a focus on imaging findings.

Proximal peroneus longus tear: rare case in a teenage athlete and review of the literature.

We present the case of a 15-year-old teenager who sustained an ankle inversion injury while playing American football, which yielded only minimal pain, but also foot numbness and a lateral leg bulge. Magnetic resonance imaging evaluation revealed a proximal peroneal tear. These rare injuries are often associated with compartment syndrome, a surgical emergency, which was ultimately excluded clinically in this patient. Relevant anatomy, mechanism of injury, and clinical manifestations are discussed.

Gadolinium-based contrast agents in pediatric magnetic resonance imaging.

Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available.

Radiographic assessment of congenital malformations of the upper extremity.

Congenital and developmental malformations of the upper extremity are uncommon and their diagnosis can challenge radiologists. Many complex classification systems exist, the latest of which accounts for the complex embryology and pathogenetic mechanisms that govern the formation of these anomalies. Using appropriate descriptors allows for more specific diagnosis and improved consultation with referring pediatricians and surgeons, helping to guide medical and surgical interventions and, if indicated, further investigation for associated abnormalities and underlying syndromes. We review the imaging characteristics of upper limb malformations to help pediatric radiologists better understand the classification and workup necessary in these cases.

Utilization of chemical shift MRI in the diagnosis of disorders affecting pediatric bone marrow.

OBJECTIVE: MRI signal intensity of pediatric bone marrow can be difficult to interpret using conventional methods. Chemical shift imaging (CSI), which can quantitatively assess relative fat content, may improve the ability to accurately diagnose bone marrow abnormalities in children. METHODS: Consecutive pelvis and extremity MRI at a children's hospital over three months were retrospectively reviewed for inclusion of CSI. Medical records were reviewed for final pathological and/or clinical diagnosis. Cases were classified as normal or abnormal, and if abnormal, subclassified as marrow-replacing or non-marrow-replacing entities. Regions of interest (ROI) were then drawn on corresponding in and out-of-phase sequences over the marrow abnormality or over a metaphysis and epiphysis in normal studies. Relative signal intensity ratio for each case was then calculated to determine the degree of fat content in the ROI. RESULTS: In all, 241 MRI were reviewed and 105 met inclusion criteria. Of these, 61 had normal marrow, 37 had non-marrow-replacing entities (osteomyelitis without abscess n = 17, trauma n = 9, bone infarction n = 8, inflammatory arthropathy n = 3), and 7 had marrow-replacing entities (malignant neoplasm n = 4, bone cyst n = 1, fibrous dysplasia n = 1, and Langerhans cell histiocytosis n = 1). RSIR averages were: normal metaphyseal marrow 0.442 (0.352-0.533), normal epiphyseal marrow 0.632 (0.566-698), non-marrow-replacing diagnoses 0.715 (0.630-0.799), and marrow-replacing diagnoses 1.06 (0.867-1.26). RSIR for marrow-replacing entities proved significantly different from all other groups (p < 0.05). ROC analysis demonstrated an AUC of 0.89 for RSIR in distinguishing marrow-replacing entities. CONCLUSION: CSI techniques can help to differentiate pathologic processes that replace marrow in children from those that do not.

Differentiating os acromiale from normally developing acromial ossification centers using magnetic resonance imaging.

OBJECTIVE: Acromial fusion may not be complete until age 18-25, making it questionable to diagnose os acromiale in adolescents. Os acromiale may exist in adolescents and can be differentiated from a developing acromial ossification center based on MRI findings. MATERIALS AND METHODS: A total of 128 MRIs of the shoulder were randomly and blindly reviewed retrospectively by two musculoskeletal radiologists. The MRIs consisted of two groups: (1) 56 of os acromiale in adults (25-74 years old, mean, 50) and (2) 72 consecutive of adolescents (12-17 years old, mean, 14.5). The following were assessed at the interface between the distal acromion and os acromiale/developing ossification center(s): presence of os acromiale vs. developing acromion, orientation, margins, and edema within and adjacent to it. RESULTS: Fifty-one adults and 49 adolescents were included. Exclusions were due to poor image quality or confounding findings (n = 7) or complete acromial fusion (n = 21 adolescents). Utilizing accepted definitions of os acromiale, all adult cases (100 %) were accurately diagnosed as os acromiale, with transverse interface orientation and irregular margins (94 %, R = 0.86, p < 0.00001). Forty-five (92 %) adolescent cases were accurately diagnosed as normally developing acromion with arched interface and lobulated margins (92 %, R = 0.92, p < 0.000001). Four (8 %) adolescent cases were diagnosed as having os acromiale, with transverse orientation and irregular margins. Thirty-five (69 %) and 46 (90 %) adults had marrow and interface edema, respectively. Six (12 %) and eight (16 %) adolescents had marrow and interface edema, respectively, including the four concluded to be os acromiale. CONCLUSIONS: Adolescents may have imaging findings consistent with os acromiale. The diagnosis of os acromiale should be based on imaging features and not limited by age.

Free-breathing contrast-enhanced T1-weighted gradient-echo imaging with radial k-space sampling for paediatric abdominopelvic MRI.

OBJECTIVE: To compare the image quality of contrast-enhanced abdominopelvic 3D fat-suppressed T1-weighted gradient-echo imaging with radial and conventional Cartesian k-space acquisition schemes in paediatric patients. METHODS: Seventy-three consecutive paediatric patients were imaged at 1.5 T with sequential contrast-enhanced T1-weighted Cartesian (VIBE) and radial gradient echo (GRE) acquisition schemes with matching parameters when possible. Cartesian VIBE was acquired as a breath-hold or as free breathing in patients who could not suspend respiration, followed by free-breathing radial GRE in all patients. Two paediatric radiologists blinded to the acquisition schemes evaluated multiple parameters of image quality on a five-point scale, with higher score indicating a more optimal examination. Lesion presence or absence, conspicuity and edge sharpness were also evaluated. Mixed-model analysis of variance was performed to compare radial GRE and Cartesian VIBE. RESULTS: Radial GRE had significantly (all P < 0.001) higher scores for overall image quality, hepatic edge sharpness, hepatic vessel clarity and respiratory motion robustness than Cartesian VIBE. More lesions were detected on radial GRE by both readers than on Cartesian VIBE, with significantly higher scores for lesion conspicuity and edge sharpness (all P < 0.001). CONCLUSION: Radial GRE has better image quality and lesion conspicuity than conventional Cartesian VIBE in paediatric patients undergoing contrast-enhanced abdominopelvic MRI. KEY POINTS: • Numerous techniques are required to provide optimal MR images in paediatric patients. • Radial free-breathing contrast-enhanced acquisition demonstrated excellent image quality. • Image quality and lesion conspicuity were better with radial than Cartesian acquisition. • More lesions were detected on contrast-enhanced radial than on Cartesian acquisition. • Radial GRE can be used for performing abdominopelvic MRI in paediatric patients.

Relative distribution of pertinent findings on portable neonatal abdominal radiographs: can we shield the gonads?

BACKGROUND: Shielding of the gonads is a dose-saving strategy in pediatric radiography and its use is the law in New York and the majority of other states. However, routine use of gonadal shields is controversial because of concerns that important diagnostic information can be obscured. OBJECTIVE: The purpose of this study was to assess the frequency and spatial distribution of key findings on portable neonatal abdominal radiographs. MATERIALS AND METHODS: We reviewed the 2,544 portable neonatal intensive care unit anteroposterior abdominal radiographs performed in 2010 at a university medical center, of which 962 were inadequately shielded. These 962 radiographs were reviewed by pairs of pediatric radiologists for the presence of findings in different regions, including bowel abnormalities, pneumatosis, free air, inguinal hernias, osseous abnormalities, and catheter/tube tips. RESULTS: The fewest pertinent findings were present below the level of the sacrosciatic notches (n = 181, 18.8%). Of the 853 abnormalities below the level of the iliac crests in our cohort, six were isolated to these regions, whereas others had concomitant abnormalities more superiorly. Of 35 radiographs with pneumatosis or suspected pneumatosis in the pelvis, 33 had pneumatosis in more superior regions. Suspected free air was never isolated to the pelvis. Osseous abnormalities were only present in the pelvis below the sacrosciatic notch, and 37.5% of lower extremity catheters terminated below the level of the sacrosciatic notches. CONCLUSION: Pertinent findings on neonatal intensive care unit abdominal radiographs are rarely isolated to the pelvic regions.

Early occurrence of cerebral white matter abnormality detected in a neonate with salt-wasting congenital adrenal hyperplasia.

The development of white matter signal abnormalities on magnetic resonance brain imaging (MRI) in children and young adults with congenital adrenal hyperplasia has been well documented. Existing theories regarding the development of these findings include effects of electrolyte imbalances, effects of disease-related hormone abnormalities, and non-physiologic long-term administration of corticosteroids. Many of the patients previously described were normal neurologically. We describe the case of white matter signal abnormalities in a neonate with salt-wasting congenital adrenal hyperplasia who presented with seizures during the first week of life, possibly due to a transient blood calcium disturbance. This case suggests that white matter changes are not simply the result of chronic insults and that they may not always be subclinical.