Magnetic resonance imaging of pediatric pelvic masses.

Both benign and malignant pelvic masses are encountered in the pediatric population. Although ultrasonography remains the modality of choice for initial evaluation of a pediatric pelvic mass, in selected cases magnetic resonance (MR) imaging can add important diagnostic information. MR imaging has several advantages over ultrasonography and computed tomography, including superior contrast resolution and an ability to characterize abnormalities based on unique tissue characteristics. MR evaluation assists in lesion characterization, presurgical planning, and staging when a malignancy is suspected. MR imaging also offers a nonionizing imaging modality for long-term follow-up of patients undergoing therapy for malignant pelvic masses.

Musculoskeletal ultrasound of the upper extremity in children.

Musculoskeletal US is becoming more widely performed in children. Although overlap between pediatric and adult pathology exists, particularly in older children who have a more mature skeleton, there are significant differences when assessing patients who have cartilaginous ossification centers, particularly in the context of trauma. Lack of ionizing radiation and dynamic imaging capabilities are significant advantages compared to CT and MRI. Although MRI provides excellent evaluation of soft tissues, the need for general anesthesia in a subset of patients is undesirable, particularly when US can provide similar information. Radiography is the primary modality to evaluate trauma; however, musculoskeletal US can be useful to assess alignment of unossified structures, fractures that extend to involve the unossified epiphyses, occult fractures, physeal separation, presence of intra-articular bodies (particularly those that are not ossified), ligamentous injury and the occasionally encountered periosteum trapped between fracture fragments. The purpose of this article is to review commonly encountered pathologies unique to the pediatric upper extremities that are ideally imaged with sonography. Some pathology that overlaps with the adult population such as infection and sports injuries are briefly covered.

A critical evaluation of US for the diagnosis of pediatric acute appendicitis in a real-life setting: how can we improve the diagnostic value of sonography?

BACKGROUND: We have observed that day-to-day use of US for acute appendicitis does not perform as well as described in the literature. OBJECTIVE: Review the diagnostic performance of US in acute appendicitis with attention to factors that influence performance. MATERIALS AND METHODS: Retrospective review of all sonograms for acute appendicitis in children from May 2005 to May 2010 with attention to the rate of identification of the appendix, training of personnel involved and diagnostic accuracy. RESULTS: The appendix was identified in 246/1,009 cases (24.4%), with identification increasing over time. The accuracy of US was 85-91% with 35 false-positives and 54 false-negatives. Pediatric sonographers were significantly better at identifying the appendix than non-pediatric sonographers (P < 0.0001). Increased weight was the only patient factor that influenced identification of the appendix (P = 0.006). CT use was stable over the 5 years but declined in cases where the appendix was identified by US. CONCLUSION: In day-to-day use, US does not perform as purported in the literature. We do not visualize the appendix as often as we should and false-negative and false-positive exams are too common. To improve the diagnostic performance of this modality, involvement by experienced personnel and/or additional training is needed.

MRI of the pediatric knee.

OBJECTIVE: The purpose of this article is to describe findings on MRI in the evaluation of knee injury in pediatric patients. CONCLUSION: Injury patterns in the pediatric knee overlap and differ from adults. Differences include open physes, changing mechanics, and differences in ligamentous support. Awareness of normal variants, common incidental findings, and normal evolution of bone marrow aid in the interpretation.