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Widespread adoption of dual-energy computed tomography (DECT) requires evidence it does not cause higher radiation dose than conventional single-energy CT (SECT). While a few publications involving pediatric patients exist, most have focused on small cohorts. Hence, there is still a need for studies that ascertain what radiation doses are expected in larger populations that include representative ranges of patient sizes and ages. To compare radiation dose and image quality of DECT and SECT abdominopelvic examinations in children as a function of patient size. This retrospective study included 860 children (age range: 12.3±5.3 years) who underwent contrast-enhanced abdominopelvic exams on second-generation dual-source CT in a five-year period. Two groups, SECT and DECT, consisting of 430 children each, were matched by 5 effective diameters. Volume CT dose index (CTDIvol) and size-specific dose estimate (SSDE) were analyzed as a function of effective diameter. Objective image quality was compared between the groups. DECT SSDEs were lower across all effective patient diameters compared with SECT (mean: 8.5±1.8 mGv vs. 9.3±2.0 mGv, respectively, P≤0.001). DECT CTDIvol was lower compared to SECT (mean: 5.6±2.4 mGv vs. 6.1±2.7 mGv, respectively, P≤0.001) except in the smallest diameter group ( 0.05). In children, regardless of effective diameter, contrast-enhanced abdominopelvic DECT can be performed with a similar or lower dose and similar image quality compared with SECT examinations.

Widespread adoption of dual-energy computed tomography (DECT) requires evidence it does not cause higher radiation dose than conventional single-energy CT (SECT). While a few publications involving pediatric patients exist, most have focused on small cohorts. Hence, there is still a need for studies that ascertain what radiation doses are expected in larger populations that include representative ranges of patient sizes and ages.To compare radiation dose and image quality of DECT and SECT abdominopelvic examinations in children as a function of patient size.This retrospective study included 860 children (age range: 12.3±5.3 years) who underwent contrast-enhanced abdominopelvic exams on second-generation dual-source CT in a five-year period. Two groups, SECT and DECT, consisting of 430 children each, were matched by 5 effective diameters. Volume CT dose index (CTDIDECT SSDEs were lower across all effective patient diameters compared with SECT (mean: 8.5±1.8 mGv vs. 9.3±2.0 mGv, respectively, P≤0.001). DECT CTDIIn children, regardless of effective diameter, contrast-enhanced abdominopelvic DECT can be performed with a similar or lower dose and similar image quality compared with SECT examinations.

A 13-year-old girl was incidentally found to have a partially calcified anterior mediastinal mass during the work-up for a left humeral lesion. The resected specimen demonstrated a lymphocyte predominant World Health Organization type B1 thymoma with nodules of metaplastic bone consistent with osseous metaplasia. In addition, she had multiple osteochondromas, a periosteal chondroma of the humerus, a metaplastic osseous pseudotumor of the thigh, and other benign-appearing sclerotic foci, all manifestations of what is likely an autosomal dominant disorder.

Background: MRI is an effective tool in evaluating bone marrow metastases. However, no study has defined which MRI sequences or image characteristics best correlate with bone-marrow metastases in neuroblastoma. Objective: To identify and refine MRI criteria and sequence selection for the diagnosis of bone-marrow metastases in children with neuroblastoma. Materials and methods: Ninety-one children (mean age: 3.2 years; standard deviation: 2.8 years) enrolled in the RDOG IV study participated in our study. Forty-five children had bone metastases determined by bone-marrow aspiration or biopsy (n=4), radionuclide imaging (n=2), or both (n=39). Spine lesions were characterized using coronal T1-weighted (T1W) sagittal short tau inversion recovery (STIR) and coronal gadolinium-enhanced T1-weighted (GAD) MR sequences. Contingency table analysis was performed to determine which MRI sequences and characteristics were associated with metastases. The MRI criteria for metastatic disease were then developed for each imaging sequence. The sensitivity, specificity, predictive values, and accuracy of these criteria were determined for the whole group, children younger than 12 months old, and children 12 months and older. Results: The MR characteristics that had significant (P ≤ 0.05) associations with metastases were homogeneous low T1-signal intensity, homogeneous high STIR-signal intensity, and heterogeneous pattern on T1, STIR, or GAD. Homogeneous low T1-signal had the highest sensitivity (88%), but a specificity of 62% for detecting metastases. A heterogeneous pattern on GAD was highly specific (97%), but relatively insensitive (65%) for detecting metastases. These MR characteristics were most accurate in children 12 months and older. Conclusion: The combination of non-contrast-enhanced T1W and GAD sequences can be used to determine the presence of spinal metastases in children with neuroblastoma, particularly those children who are 1 year and older.

Phosphaturic mesenchymal tumor is an uncommon cause of a paraneoplastic syndrome that can be associated with osteogenic osteomalacia. This tumor most commonly occurs in middle-aged men and women. We report a rare case of a phosphaturic mesenchymal tumor in a 16-year-old girl with multiple fractures as a result of severe osteoporosis. CT and MRI showed a mass arising from the tibia.

We prospectively evaluated a total of nineteen symptoms, signs, and laboratory findings in 471 of 557 consecutive pediatric patients (from newborn to age 17) referred for barium enema examinations, to determine predictors of an abnormal study. A univariate analysis was performed, and a logistic regression model was developed. The most frequent indicators for the barium enema examinations were abdominal pain (48%), constipation (27%) and tenderness (25%). Twenty-two percent of the examinations were abnormal, and the most common diagnoses were intussusception (n = 22), appendicitis (n = 17), infectious colitis (n = 15), and Hirschsprung disease (n = 14). The indicators that were most helpful to predict a barium enema abnormality were abdominal mass, leukocytosis, guaiac-positive stools, diarrhea, anemia, tenderness, and age less than 1 year. If barium enema examinations were performed only when at least one of the predictive indicators was present, 29% of examinations would be eliminated, and 4.8% of patients with detectable disease would be missed. The data indicate that identification of certain clinical variables can provide an effective initial strategy for selecting patients to undergo barium enema examinations.

A retrospective study of cranial sonograms in infants with autosomal trisomies excluding Down's syndrome was performed. A range of abnormalities was found including structural anomalies, vascular changes and hydrocephalus. Although nonspecific, many of these abnormalities can suggest a specific chromosomal abnormality in the appropriate clinical setting.

Hemolytic-uremic syndrome associated with Escherichia coli 0157:H7 presents with a gastrointestinal prodrome. During this prodrome the disease may be difficult to differentiate from acute colitis and other hemorrhagic gastrointestinal diseases. We have found that color Doppler sonography in patients with E. coli-associated hemolytic-uremic syndrome of the colon demonstrates a strikingly avascular, thick-walled colon. In the correct clinical setting, this finding should allow a diagnosis during the prodromal phase.

MRE uses low-frequency mechanical waves to interrogate elasticity of tissue. There are three steps in performing MRE. First, a mechanical drumlike device is placed on the abdominal wall to generate shear waves (frequency 40– 120 Hz). Next, the waves are imaged using a phase-contrast MR imaging sequence. Third, wave data are processed to create a color elastogram, an image that quantitatively depicts tissue stiffness. Liver stiffness is calculated by placing regions of interest in selected locations on the elastogram. The average acquisition time for hepatic MRE is approximately 15 s, so the addition of MRE into a conventional MRI examination of the liver adds very little to the total examination time.

Real-time abdominal sonograms of 27 pediatric patients with cystic fibrosis were reviewed to determine the frequency of hepatobiliary abnormalities and their variation with patient age. Attention was paid to hepatic echotexture and gallbladder size and contents. Seventeen patients (63%) had abnormal livers appearing as diffuse hyperechogenicity with loss of visualization of periportal echoes in 5 of 17 patients (29%), periportal hyperechogenicity in 9 of 17 (53%) and heterogeneity in 3 of 17 (17%). Gallbladder abnormalities, including a small gallbladder and sludge, were found in 9 patients (33%). Our findings show that altered hepatic echotexture is quite common in children with cystic fibrosis. Younger children tend to have diffusely hyperechoic livers, while older children often demonstrate periportal hyperechogeneity or diffuse hepatic heterogeneity.

After noting several occurrences of cystic kidney disease in Turner's syndrome we retrospectively reviewed the renal sonograms of 12 patients with this syndrome. Single renal cysts occurred in two patients and a multicystic dysplastic kidney in another. Our experience suggests that single renal cysts are a relatively frequent finding in Turner's syndrome and should be recognized within the scope of renal abnormalities associated with it.

A phenotypically female infant with 46-XY chromosomes was found to have Smith-Lemli-Opitz syndrome, type II a rare congenital malformation syndrome with many features of the more common classic Smith-Lemli-Opitz syndrome. The patient's skeletal survey revealed characteristic and previously undescribed skeletal anomalies which are reported. In addition a lipoma of the pituitary gland was found on magnetic resonance imaging. This lesion is particularly interesting given the hypothesized steroid abnormality in Smith-Lemli-Opitz, type II syndrome, the sexual ambiguity of males with this syndrome and the similarity of this syndrome to the Pallister-Hall syndrome which characteristically has a hamartoblastoma of the hypothalamus.

A marked thoracic deformity associated with intrathoracic tracheal narrowing was seen in a 17-year-old with achondroplasia and dyspnea. The role of chest deformity and its evaluation by CT and MRI in achondroplastic patients with respiratory symptoms are considered.

A patient with a recurrent left neck abscess was found to have a branchial fistula from the pyriform sinus. This uncommon anomaly was demonstrated by CT and barium swallow. The embryology, pathology and clinical features of this lesion are discussed and contrasted with those of the branchial cyst.

A cardiac fibroma in a newborn is reported. The infant had skeletal stigmata of Gorlin's syndrome and the mother had known Gorlin's syndrome.

Striking pyramidal hyperechogenicity resembling the sonographic appearance of medullary nephrocalcinosis was found in autosomal recessive polycystic kidney disease (ARPKD). This sonographic pattern is distinctly different from those described previously in ARPKD.

Plain roentgenograms were taken prior to oral cholecystography in 100 children. Three children had their gallstones obscured by the oral cholecystographic agent. Consideration should be given to obtaining plain roentgenograms in children with a strong clinical suspicion of gallbladder disease and a normal oral cholecystogram.

Gastric teratoma is a rare benign tumor with a striking male predominance in patients under one year of age. The common presenting features are a palpable mass producing gastro-intestinal hemorrhage or respiratory distress. Approximately 50% of gastric teratomas may show calcification on plain abdominal roentgenograms. Two cases in newborns are reported, and the clinical and radiologic features of gastric teratomas reviewed.

In three patients the diagnosis of an anomalous left pulmonary artery was confirmed when tracheobronchography demonstrated a discrete extrinsic impression on the proximal right bronchus. The diagnosis was unsuspected clinically in one patient with a hyperlucent left lung on conventional chest radiographs. In the other two patients there was a suspicion of a pulmonary sling, but findings on plain chest or airway radiographs were atypical. The tracheobronchogram can be a valuable procedure for diagnosing a pulmonary sling, detecting additional developmental anomalies of the bronchi, and predicting the post-operative clinical course.

Three infants with fatal aspirations during gastroesophageal studies are reported because of the rarity of this catastrophe in the literature. Recommendations for avoiding this complication are suggested.