Faculty Bibliography

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of focused appendicitis ultrasound combined with Alvarado score to accurately identify appendicitis in children in whom it is suspected, thereby reducing unnecessary CT examinations and associated radiation exposure. MATERIALS AND METHODS: We retrospectively evaluated the focused appendicitis ultrasound, CT, clinical, and laboratory findings of 522 consecutively registered children (231 boys, 291 girls; mean age, 13.04 [SD, 5.02] years; range, 0.74 months-21 years) who underwent focused appendicitis ultrasound for abdominal pain in a pediatric emergency department from January 2008 through October 2009. All children underwent surgery or clinical follow-up to exclude missed appendicitis. Sonographic findings were characterized as positive, negative, or inconclusive (appendix not visualized). Alternative diagnoses were noted. Alvarado score (0-10 points based on multiple clinical criteria) was determined. Focused appendicitis ultrasound and Alvarado score results were compared with surgical and pathologic reports. RESULTS: Both focused appendicitis ultrasound results and Alvarado score were associated with likelihood of surgery for appendicitis (p = 0.0001). Focused appendicitis ultrasound had conclusive results: 105 positive and 27 negative in 132 of 522 (25.2%) children. In the 390 of 522 (74.7%) children with inconclusive focused appendicitis ultrasound findings, 43 of 390 (11.0%) eventually had a diagnosis of appendicitis with CT (n = 26) or Alvarado score (n = 17). Among children with inconclusive focused appendicitis ultrasound findings and an Alvarado score less than 5 (241/522, 46.1%), only one patient had appendicitis. The negative predictive value (NPV) of inconclusive ultrasound findings and low Alvarado score combined was 99.6%. Among children with inconclusive focused appendicitis ultrasound findings and an Alvarado score of 5-8, the NPV decreased to 89.7%. CONCLUSION: Children with inconclusive focused appendicitis ultrasound findings and a low Alvarado score are extremely unlikely to have appendicitis (NPV, 99.6%). Avoiding unnecessary CT of these patients is a safe approach to diagnosis.

PURPOSE: To evaluate the contribution of 3D reconstruction in assessing lower tracheobronchial pathology and surgical interventions. METHODS: Twenty patients fit our criteria of lower tract tracheobronchial pathologies for a total of 25 abnormalities. Studies were reviewed by two board certified pediatric radiologists. Diagnostic value of 3D reconstruction in assessing surgical findings was evaluated. RESULTS: Three-dimensional (3D) reconstruction was perceived to add specific information in seven cases: three cases clarifying how attempting surgical intervention would be helpful, and in four cases, 3D reconstruction gave added information that aided surgical planning. CONCLUSIONS: Three-dimensional reconstructions can be a helpful tool in planning surgical interventions.

OBJECTIVE: Acute appendicitis is the most common condition requiring emergency surgery in children. Differentiation of perforated from nonperforated appendicitis is important because perforated appendicitis may initially be managed conservatively whereas nonperforated appendicitis requires immediate surgical intervention. CT has been proved effective in identifying appendiceal perforation. The purpose of this study was to determine whether perforated and nonperforated appendicitis in children can be similarly differentiated with ultrasound. MATERIALS AND METHODS: This retrospective study included 161 consecutively registered children from two centers who had acute appendicitis and had undergone ultra-sound and appendectomy. Ultrasound images were reviewed for appendiceal size, appearance of the appendiceal wall, changes in periappendiceal fat, and presence of free fluid, abscess, or appendicolith. The surgical report served as the reference standard for determining whether perforation was present. The specificity and sensitivity of each ultrasound finding were determined, and binary models were generated. RESULTS: The patients included were 94 boys and 67 girls (age range, 1-20 years; mean, 11 +/- 4.4 [SD] years) The appendiceal perforation rate was significantly higher in children younger than 8 years (62.5%) compared with older children (29.5%). Sonographic findings associated with perforation included abscess (sensitivity, 36.2%; specificity, 99%), loss of the echogenic submucosal layer of the appendix in a child younger than 8 years (sensitivity, 100%; specificity, 72.7%), and presence of an appendicolith in a child younger than 8 years (sensitivity, 68.4%; specificity, 91.7%). CONCLUSION: Ultrasound is effective for differentiation of perforated from nonperforated appendicitis in children.

OBJECTIVE: Obesity is a growing clinical problem, especially among children of low socioeconomic status. Increased visceral abdominal fat is implicated in the metabolic syndrome and its health consequences. The purpose of this study is to validate measurement of a single MDCT slice as a predictor of total visceral abdominal fat and to correlate over a wide range of body mass indexes (BMIs). MATERIALS AND METHODS: A two-phase retrospective analysis was performed. For validation, MDCTs of 21 consecutive healthy children (8-14 years old) were reviewed. In these cases, visceral abdominal fat and subcutaneous abdominal fat area were calculated using a body fat analysis function from single 0.625-mm MDCT slices at the umbilicus and were compared with total visceral abdominal fat area as measured from T11 to the coccyx. Subsequently, visceral abdominal fat area was obtained from single slices at the umbilicus from abdominal MDCT scans of 146 consecutive healthy children (age range, 6-14 years; 80 boys and 66 girls; 77 Hispanic, 41 African American, 15 white, and 13 multiracial or other race) for whom BMI was available. Associations between visceral abdominal fat area and sex, race, and BMI were determined. Effective radiation dose for a 1.25-mm axial MDCT slice was calculated using a mathematic model that uses derived scaling factors for pediatric patients. RESULTS: Visceral abdominal fat area obtained from a 0.625-mm slice at the umbilicus was highly correlated with total visceral abdominal fat area (r = 0.96; p < 0.0001). Visceral abdominal fat area from single slices at the umbilicus was significantly correlated with BMI (r = 0.72; p < 0.0001). Umbilical visceral abdominal fat area was significantly lower in African American children compared with others (median, 14 vs 22 cm(2); p = 0.02) and was not associated with sex. In our population, the effective radiation dose from the smallest obtainable slice was 0.015-0.019 mSv/37-54 kg of patient weight. CONCLUSION: Visceral abdominal fat area calculated from a single abdominal MDCT slice obtained in children is highly correlated with total visceral abdominal fat and with BMI and involves limited radiation exposure.

OBJECTIVE: The purpose of this study was to illustrate the spectrum of solitary gluteal lesions in children. The distinctive anatomic and radiologic features are discussed. CONCLUSION: Pathologic entities in the gluteal region reflect the diversity of tissue types present. Ultrasound is valuable for imaging of infants and young children and for evaluating superficial lesions. Cross-sectional imaging is most useful for defining the extent of disease and may show pathognomonic features, enabling a precise diagnosis.

BACKGROUND: Gastric volvulus in children is uncommon, and characteristic radiographic findings might not be recognized. OBJECTIVE: To present the spectrum of clinical and imaging findings, correlate the type of gastric volvulus with clinical outcome, and identify imaging findings to aid in early diagnosis. MATERIALS AND METHODS: Medical records and imaging findings of ten children with gastric volvulus were reviewed. Imaging included abdominal radiographs, upper gastrointestinal (UGI) series, and CT. The diagnosis (organoaxial, mesenteroaxial or mixed type) was made on the UGI series (n = 9) and CT (n = 1), and confirmed surgically in seven children. RESULTS: Patients were classified based on presentation: four acute, four chronic, and two neonatal. All of the acute group (three mesenteroaxial and one mixed type) had abnormal radiographic findings: three spherical gastric distension, four paucity of distal gas, three elevated left hemidiaphragm, one overlapping pylorus and gastric fundus, one unusual nasogastric tube course, and one situs inversus. All underwent emergent surgery. Three had diaphragmatic abnormalities. One had heterotaxy. Patients in the chronic group (three organoaxial, one mesenteroaxial) had long-standing symptoms. Most had associated neurologic abnormalities. In the neonatal group, organoaxial volvulus was found incidentally on the UGI series. CONCLUSION: A spectrum of findings in gastric volvulus exists. Mesenteroaxial volvulus has greater morbidity and mortality. Radiographic findings of spherical gastric dilatation, paucity of distal gas and diaphragmatic elevation are suggestive of acute volvulus, particularly in patients with predisposing factors.

We report on the clinical phenotype of an infant with a duplication of the terminal portion of the long arm of chromosome 3(q26.3-qter) and a deletion of the terminal portion of the short arm of chromosome 4(p16.3) with multiple hemangiomas and a hamartoma. Patients with deletions of distal 4p have the characteristic features of Wolf-Hirschhorn syndrome (WHS); whereas those with the distal duplication of 3q have a well recognized syndrome with some features resembling Cornelia-de Lange syndrome (CdLS). Neither of these recognized chromosomal anomalies has been reported previously to be associated with multiple hemangiomas or other vascular malformations.

OBJECTIVES: Renal medullary carcinoma (RMC) is a devastating and extremely rare malignancy primarily afflicting young men with sickle cell trait. We present our clinical experience with 9 cases of RMC during a 10-year period and briefly review the published data. METHODS: A retrospective chart review of 9 cases of RMC during a 10-year period at our institutions was performed. The clinical patient characteristics, presentations, treatments, and outcomes were recorded. The radiographic images and pathologic specimens were reviewed. Applicable studies were selected from a Medline search. RESULTS: All 9 patients had sickle cell trait, the male/female ratio was 6:3, and the age range was 13 to 31 years. All the patients presented with flank pain, two thirds had hematuria, and 3 of the 9 patients presented with a palpable mass. Eight of the nine tumors were right sided, ranging from 4 to 12 cm in the greatest diameter. Of the 9 patients, 7 underwent radical nephrectomy. One patient was deemed to have unresectable disease by the operating surgeon, and one was given initial chemotherapy after biopsy of a metastatic lesion. The neoadjuvant therapies varied. Overall survival ranged from 4 to 16 months, with 2 patients still living at the last follow-up visit. CONCLUSIONS: Our urban setting likely explains our relatively large experience with this rare and extremely aggressive tumor. An early diagnosis is critical, and a high index of suspicion should be given to any individual with sickle cell trait and new-onset hematuria, especially in the setting of a right-sided mass. Prospective trials are needed for chemotherapy/immunotherapy, because surgical intervention alone is inadequate.

Spontaneous subperiosteal hemorrhage is a rare complication of von Recklinghausen's disease. There are few reports describing the MR imaging characteristics of this entity. Our case is unique among these as an underlying plexiform neurofibroma was visualized by MR imaging. We present a 12-year-old child with neurofibromatosis 1 who presented with a rapidly enlarging mass of the fibula. Surgery and pathology revealed subperiosteal hemorrhage into a benign, plexiform neurofibroma. The MR imaging features, pathogenesis and clinical implications of this entity are discussed. Recognition of this disease process and differentiating it from malignant transformation can prevent unnecessary surgery.

PURPOSE: To systematically assess the frequency and risk factors for atelectasis in children anesthetized for cardiothoracic magnetic resonance (MR). MATERIALS AND METHODS: We retrospectively identified 58 consecutive children (age range, 6 days to 21 years) who underwent cardiothoracic MR from January 2001 to December 2004 whose imaging and medical charts were available. One certificate of added qualification pediatric radiologist and 1 of 2 cardiothoracic radiologists, in consensus, evaluated the first and last set of axial images. Images were evaluated for cardiac, vascular and tracheobronchial abnormalities, and degree of atelectasis. Atelectasis was considered significant if the equivalent of 3 or more segments were involved. Patients received 1 or more of 7 anesthetic medications (n = 27), chloral hydrate alone (n = 4), or required no anesthesia (n = 27). RESULTS: Significant atelectasis developed only in those receiving anesthetic medications. Thirty-seven percent (10/27) of anesthetized children developed significant atelectasis in the first and/or last axial sequence. In 90% (9 /10) of patients, it developed in the first axial sequence. Strong risk factors were age younger than 1 year (80%, 8/10, P = 0.029) and MR evidence of tracheobronchial narrowing (50%, 5/10, P = 0.008). In patients with vascular ring, there was a trend toward significance (40%, 4/10, P = 0.09). None of the anesthesia factors were significant, including ventilation mode, anesthesia duration, or American Society of Anesthesiology risk (all P > 0.1). CONCLUSIONS: Atelectasis may occur shortly after induction of anesthesia in children younger than 1 year of age or with tracheobronchial narrowing when anesthetized for cardiothoracic MR.