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Cardiac magnetic resonance is a powerful, rapidly advancing technology that complements other imaging modalities in the noninvasive evaluation of congenital heart disease. Magnetic resonance plays an important role in diagnosis and follow-up by assessing anatomic features, functional effects, and postoperative complications. An understanding of the pathophysiology and imaging characteristics of various congenital heart lesions is essential for effective implementation and accurate interpretation of the cardiac magnetic resonance examination.

Neuroblastoma is one of the most common non-central nervous system solid tumors in children. Imaging plays a role in the evaluation of the primary tumor and regional and distant disease. This article reviews the biologic, clinical, and MR imaging features of this tumor.

Wilms' tumor is the most common solid renal tumor in children. Imaging plays a crucial role in the evaluation of the primary tumor and regional and metastatic disease. This article reviews the biologic, clinical, and MR imaging features of this tumor and other renal tumors that can mimic Wilms' tumor.

The introduction of the graded-compression sonographic technique and continued advances in ultrasound technology have increased the use of sonography in evaluating the child who has a suspected surgical abdomen. Sonography is used to characterize the nature of the many conditions associated with acute abdominal symptoms and signs and to differentiate between those requiring urgent surgical intervention and those that do not. This article reviews the sonographic evaluation of common important surgical conditions of the abdomen in children. Indications for performing sonography, sonographic features of common lesions, and the sonographic techniques best suited to making a diagnosis are addressed.

Advances in multidetector computed tomography (CT) technology have revolutionized thoracic imaging in children. Faster scanning times, increased anatomic coverage, and high quality reconstructions have enabled CT to become a valuable tool in the evaluation of thoracic diseases. CT images are helpful in detecting, characterizing and determining the extent of abnormalities in the lungs, mediastinum, vasculature, chest wall and peridiaphragmatic regions. The information provided by these techniques can directly affect the treatment or aid in determining the prognosis of a patient.

This is an expert consensus document created to provide information about the current use of cardiovascular computed tomography (CT) in patients of all ages with proven or suspected congenital heart disease (CHD). The discussion and recommendations are based on available literature and the judgment of a diverse group of subspecialists with extensive experience in the use of CT imaging in CHD. The field of CHD CT imaging is evolving rapidly with the availability of new scanner technology. In addition, the prevalence of palliated CHD has increased with marked improvements in patient survival. We believe it is important to review the clinical indications, strengths, limitations, and risks of cardiovascular CT in this patient population. This is the first of two complementary documents. It will concentrate on the disease entities and circumstances in which CT may be used. The second document will focus on recommendations for the technical performance of cardiovascular CT in patients with CHD. Successful cardiovascular CT imaging of CHD requires an in depth understanding of the core teaching elements of both cardiology and radiology. The ability to perform and interpret high quality congenital cardiovascular CT in a clinical context requires focused time and effort regardless of the previous background of the cardiac imager. This is reflected by a writing committee that consists of pediatric and adult radiologists and cardiologists, all whom have extensive experience in performing CT in this patient population. Cardiovascular CT is complementary to other imaging modalities and its optimal use will be in centers where all diagnostic modalities are available. The choice of modality for an individual patient should be determined by age, diagnosis, clinical condition, clinical question and patient preference.(1-4) Use of CT in CHD should be reserved for situations in which it is expected to provide unique diagnostic information for the individual patient or clinical indication, and/or less risk than other modalities. This multi-disciplinary document is intended to guide the optimal selection of CHD patients for cardiovascular CT. The goals of this document apply to both pediatric and adult CHD patients and are to.

The aim of this study was to determine whether the use of multidetector computed tomography (MDCT) is associated with decreased sedation, frequency of motion artefacts and conventional angiograms compared with single-detector CT (SDCT).CT examinations performed in young children between January 1993 and June 2005 were reviewed retrospectively. Prior to September 2000, SDCT was used; after that period, MDCT was used. The examinations obtained during these two periods were compared for the frequency of sedation, motion artefacts, and conventional angiograms. Statistical comparison between the two groups was determined by using the chi(2) test.A total of 126 infants and children younger than 6 years of age underwent 134 CT examinations. Eighty-eight were obtained with a SDCT (65%) (group 1) and 46 with a MDCT (35%) (group 2). Sedation was required in 31/88 (35%) CT examinations in group 1 and in 6/46 (13%) in group 2. Conventional angiography was performed in 20/88 (22%) cases in group 1 and in 6/46 (13%) in group 2. Motion artefacts were present in 8/88 (9%) CT examinations in group 1 and in 4/46 (8%) in group 2. There was significant statistical difference with regard to sedation and angiography rates between the two groups (p0.001) whereas there was no significant difference with regard to motion artefacts (p1).MDCT can reduce the need for sedation and conventional angiography in children after liver transplantation. There is no effect on patient motion artefacts.

Advances in CT technology are having profound impact on imaging children and have made CT angiography possible even in neonates. Even with the tiny anatomy of neonates, small volumes of contrast material, and small venous access catheters, successful CT angiography can be performed with attention to detail. Meticulous attention to patient preparation, the proper selection of technical factors, and optimal delivery of contrast material are crucial. Data post-processing and the creation of 3-D reconstructions are also essential in establishing a correct diagnosis. The applications of CT angiography are different in children than in adults and most applications in children involve assessment of congenital and postoperative vascular and cardiac diseases. The use of CT angiography offers the opportunity to eliminate the long periods of sedation associated with MR and reduce the radiation exposure associated with conventional angiography. Generally, the benefits of CT angiography in children outweigh the risk, namely that of radiation exposure. However, care must still be taken to minimize the radiation exposure.

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.

Tumors of the renal medulla cover a wide spectrum, with characteristic histomorphology and variable biologic profiles. Renal medullary tumors can be categorized into benign and malignant neoplasms based on histologic features and clinico-biologic behavior. They can be further classified into pediatric and adult tumors based on the patient age group. When small, renal medullary tumors may be differentiated from the more common renal adenocarcinomas by their central location and certain demographic characteristics. Although most large malignant medullary tumors demonstrate imaging findings that are indistinguishable from those of other renal malignancies, some tumors demonstrate imaging findings that may suggest a specific diagnosis.

Klippel Feil syndrome with occipital encephalocele, duodenal web, left pelvic kidney, ASD, anorectal malformation fetal and postnatal imaging

To evaluate effects of varying tube current and voltage on radiation dose, image noise, and image contrast with different phantom sizes and shapes.Four round lucite phantoms with 8-32-cm diameters were scanned with multi-detector row computed tomography (CT) and 80-120 kVp. Radiation dose was based on CT dose index, image noise, and iodine contrast and measured with constant and variable tube currents that were age appropriate for each tube voltage. Radiation dose and image noise and contrast were compared in round and oval 24-cm phantoms. For various combinations of technical factors and phantom sizes and shapes, percentage differences were calculated for radiation dose and image noise and contrast. Associations between tube voltage and radiation dose, image noise, and image contrast in round and oval phantoms were determined by fitting second-degree polynomials to data. Differences in radiation dose and image noise and contrast, which were attributable to differences in tube voltage, were tested with paired t tests.With 165-mAs tube current, radiation doses with 140- and 80-kVp tube voltages were 103% ([41.9 mGy - 20.6 mGy]/20.6 mGy) and 58% ([10.2 mGy - 4.2 mGy]/10.1 mGy) higher in the 8-cm phantom than in the 32-cm phantom. When tube current was adapted for phantom size, radiation dose at 80 kVp in the 8-cm phantom was reduced by 82% ([10.1 mGy - 1.8 mGy]/10.1 mGy). In the 8-cm phantom, tube voltage was decreased from 120 to 80 kVp and tube current remained at 165 mAs, resulting in a 68% noise increase ([3.1 HU - 1.8 HU]/1.8 HU). With variable tube current, 80-kVp tube voltage in the 8-cm phantom led to a 138% noise increase ([7.3 HU - 3.1 HU]/3.1 HU). With reduced tube voltage, image contrast increased. In the 8-cm phantom, with a constant 165-mAs tube current and a decrease in tube voltage from 120 to 80 kVp, there was a 35% ([333 HU - 217 HU]/333 HU) increase in contrast. No difference was noted in radiation dose or noise between round and oval phantoms (P = .604 and P = .06, respectively), but a small statistically significant difference (1%) in contrast attenuation was demonstrated (P = .025).Reduced tube voltage for pediatric contrast material-enhanced CT reduces radiation dose and maintains image contrast. Image noise increases, but the effect is minimal in smaller phantoms. An additional reduction in tube current further reduces radiation dose.

To describe the chest radiographic appearance of the Amplatzer septal occluder (ASO) (AGA Medical Corporation, Golden Valley, Minn) for atrial septal defects (ASDs) in pediatric patients.Two radiologists independently reviewed frontal and lateral chest radiographs obtained in young patients 24 hours after transcatheter ASD closure with the ASO. The appearance (flat disks or dots) and location of the ASO were recorded. The location was related to that of a thoracic vertebral body on frontal and lateral chest radiographs and to a line drawn between the anterior margin of the right hilum and the posterior margin of the inferior vena cava (hilar-caval line) on lateral radiographs; this line corresponded to the expected position of the interatrial septum. The relationship between ASO appearance and patient age was assessed with logistic regression and cumulative probability plots.Sixty-eight pediatric patients (age range, 1 month to 18 years; mean age, 4.2 years; 24 boys and 44 girls) were included. On frontal radiographs, the ASO center projected between T7 and T9, either to the right of or over the spinous processes of the vertebral body. On lateral radiographs, the ASO projected over (n = 66) or anterior to (n = 2) the hilar-caval line. On frontal radiographs, it appeared as one or two flat disks (n = 61) or as two metallic dots (n = 7). On lateral radiographs, it appeared as two flat disks (n = 54) or as two metallic dots (n = 14). The relationship between increasing patient age and the metallic dot appearance on frontal and lateral radiographs and on the combination of frontal and lateral radiographs was highly significant in each case (P.001, likelihood ratio chi(2) test), with r(2) values of 0.35, 0.20, and 0.28, respectively. ASDs were successfully occluded with the ASO in all patients except one, in whom trivial shunting was seen at 12-month follow-up.The ASO in pediatric patients has a characteristic radiographic appearance when properly positioned.

Extralobar pulmonary sequestration (ELS) and congenital cystic adenomatoid malformation have been reported to coexist in several variations. This suggests a common embryologic origin. A 6-month-old boy presented with a history of recurrent pneumonias. The patient was diagnosed with a right lower lobe congenital cystic adenomatoid malformation (CCAM) and a left lower lobe ELS/CCAM. The diagnosis was made with the aid of a multidetector computed tomography (CT). Three-dimensional CT reconstruction showed the presence of a right lower lobe CCAM, a left lower ELS with an aberrant arterial supply from the celiac axis, and possible venous drainage into the right CCAM. The patient underwent a right thoracotomy. Intraoperatively, the lesions were discovered to be connected by a band of tissue. The right lower lobe CCAM and the left ELS were removed from the right chest. Histologic analysis confirmed the presence of a CCAM within the right lower lobe. The ELS had involvement of a type II CCAM within the sequestration. The connection between the right CCAM and left ELS/CCAM showed an anomalous conducting airway, anomalous vein, and anomalous artery connecting the 2 lesions. The authors present the first case of a CCAM connected to an ELS/CCAM in the contralateral hemithorax. The unique anatomic configuration of these lesions suggests a common embryologic origin of ELS and CCAM.

Multi-detector row computed tomography (CT) has changed the approach to imaging of thoracic anatomy and disease in the pediatric population. At the author's institution, multi-detector row CT with multiplanar and three-dimensional reconstruction has become an important examination in the evaluation of systemic and pulmonary vasculature and the tracheobronchial tree. In some clinical situations, multi-detector row CT with reformatted images is obviating conventional angiography, which is associated with higher radiation doses and longer sedation times. Although multi-detector row CT with multiplanar and three-dimensional reconstruction is expanding the applications of CT of the thorax, its role as a diagnostic tool still needs to be better defined. The purposes of this article are to describe how to perform multi-detector row CT with multiplanar and three-dimensional reconstruction in young patients, to discuss various reconstruction techniques available, and to discuss applications in the evaluation of vascular and airways diseases.

Transcatheter closure of an atrial septal defect, patent foramen ovale, or post-myocardial infarction ventricular septal defect has become a safe and effective alternative to medical and surgical therapy. Although the use of transcatheter closure of septal defects is becoming increasingly more popular, there are few reports of the radiographic appearance of the closure devices. We report the chest radiographic findings in 36 patients after transcatheter closure of septal defects with Amplatzer or CardioSEAL occluders in an effort to aid radiologists in recognizing the appearances of these devices and enable them to confirm proper positioning.

Anopthalmia/microphthlamia-esophageal atresia association with additional features imperforate anus, choanal atresia, cyanotic heart disease

MR imaging is well suited to evaluation of the pelvis. Ultrasonography remains the study of choice for the initial evaluation of a suspected gynecologic mass. MR imaging and computed tomography remain problem-solving tools that can help to characterize masses and stage gynecologic malignancies. MR imaging has the advantage of higher soft tissue contrast compared with computed tomography. This article reviews the MR findings of congenital anomalies and masses of the adnexa and uterus in adolescent girls.

MRI has become an important imaging tool that complements echocardiography in the noninvasive evaluation of congenital heart defects. It can play a crucial role in diagnosis by assessing anatomic and functional features in CHD and identifying complications and postoperative sequelae. The performance and application of cardiac MRI require not only knowledge of the clinical question that needs to be addressed but knowledge of the anatomic characteristics of a variety of congenital heart lesions. A knowledge of the advantages and disadvantages of the different imaging sequences also is important so as to optimize and expedite the examination.

To compare the accuracies of computed tomography (CT), magnetic resonance (MR) imaging, and bone scintigraphy in staging disease in patients with neuroblastoma.Ninety-six children with newly diagnosed neuroblastoma were enrolled in a multicenter prospective cohort study. CT, MR, and bone scintigraphy were used to evaluate tumor stage. Sensitivity and specificity values and receiver operating characteristic (ROC) curve analyses were used to compare the accuracy of CT, MR, and scintigraphy for tumor staging.Eighty-eight patients were eligible for staging analysis, and 45 patients who underwent surgery at initial diagnosis were eligible for analysis of local tumor extent. CT and MR had sensitivities of 43% and 83%, respectively (P.01), and specificities of 97% and 88%, respectively (P.05), for detection of stage 4 disease. Areas under the ROC curves for CT and MR were 0.81 and 0.85, respectively (P =.06); that for scintigraphy was 0.83. Addition of scintigraphy to both CT and MR increased the areas under the ROC curves to 0.90 and 0.88, respectively. Accuracy of CT and MR for staging disease confined to the chest or abdomen (stages 1, 2, and 3) was poor.MR alone and CT and MR combined with bone scintigraphy enable the accurate detection of stage 4 disease. Both CT and MR perform poorly for local tumor staging.

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.

Primary intrarenal neuroblastoma is extremely rare and is a mimic of Wilms tumor. We present a case of a renal mass in a 14month old male with lung metastases at the initial presentation. This was thought to represent a Wilms tumor. Histology of a biopsied lung nodule revealed neuroblastoma.

Computed tomography (CT), the standard method to assess tumor response to cetuximab in incurable squamous cell carcinoma of the head and neck (SCCHN), performs poorly as judged by the disparity between high disease control rate (46%) and short time to progression (TTP) (70 days). F-18 fluorodeoxyglucose positron emission tomography (FDG-PET)/CT is an alternative method to assess tumor response. The primary objective of this prospective trial was to evaluate the metabolic response of target lesions, assessed as the change in maximum standardized uptake value (SUV(max)) on FDG-PET/CT before and after 8 weeks (cycle 1) of cetuximab. Secondary objectives were to compare tumor response by CT (RECIST 1.0) and FDG-PET/CT (EORTC criteria) following cycle 1, and determine TTP with continued cetuximab administration in patients with disease control by CT after cycle 1 but stratified for disease control or progression by FDG-PET/CT. Among 27 patients, the mean percent change of SUV(max) of target lesions after cycle 1 was -21% (range: +72% to -81%); by FDG-PET/CT, partial response (PR)/stable disease (SD) occurred in 15 patients (56%) and progression in 12 (44%), whereas by CT, PR/SD occurred in 20 (74%) and progression in 7 (26%). FDG-PET/CT and CT assessments were discordant in 14 patients (P = 0.0029) and had low agreement (κ = 0.30; 95% confidence interval [CI]: 0.12, 0.48). With disease control by CT after cycle 1, median TTP was 166 days (CI: 86, 217) if the FDG-PET/CT showed disease control and 105 days (CI: 66, 159) if the FDG-PET/CT showed progression (P0.0001). Median TTP of the seven patients whose post cycle 1 CT showed progression compared to the 12 whose FDG-PET/CT showed progression were similar (53 [CI: 49, 56] vs. 61 [CI: 50, 105] days, respectively). FDG-PET/CT may be better than CT in assessing benefit of cetuximab in incurable SCCHN.

Background: The diagnosis of esophageal atresia may be suspected on prenatal ultrasound scan in fetuses with a small or absent stomach or unexplained polyhydramnios. However, these findings are thought to have a low positive predictive value and clinical decisions affecting timing or site of delivery may be made erroneously. The authors evaluated the accuracy of fetal sonography followed by magnetic resonance imaging (MRI) for the diagnosis of this lesion. Methods: Fetuses considered to be at risk for esophageal atresia based on detailed obstetric sonography underwent fetal MRI using a single-shot rapid-acquisition technique, and the T 2 -weighted images were evaluated prospectively. Scans were considered to be positive if the proximal esophagus was dilated, and the distal esophagus was not seen and negative if the esophagus was visualized throughout its length. Results: Ten fetuses underwent MRI scanning. All had a small or absent stomach bubble with unexplained polyhydramnios. Four scans were considered to be negative for esophageal atresia; all 4 were found to have a normal esophagus after delivery. Six scans were considered to be positive; 5 had esophageal atresia (2 with tracheoesophageal fistula and 3 without), and one had a neurologic syndrome with a normal esophagus. Conclusions: Magnetic resonance imaging appears to be accurate for establishing or ruling out a prenatal diagnosis of esophageal atresia, and should be considered in fetuses who are at high risk based on ultrasound findings. J Pediatr Surg 36:804-807. Copyright © 2001 by W.B. Saunders Company.

OBJECTIVE To assess the sonographic findings of breast masses in adolescents and the usefulness of sonographic patterns for suggesting a specific diagnosis. METHODS The sonograms and medical records of 57 girls (mean age, 15.4 years) with palpable breast masses were retrospectively reviewed. Three observers reviewed the sonograms for multiple sonographic findings. Surgery or clinical findings established diagnoses. Statistical analysis was done to determine how well sonographic findings alone and in combination agreed with final histologic diagnoses. RESULTS Diagnoses included cysts (n = 12), abscesses (n = 7), fibroadenomas (n = 36), a lactating adenoma (n = 1), and a phyllodes tumor (n = 1). The sonographic findings varied significantly among lesion types (P < or = .005). CONCLUSIONS Our experience suggests that virtually all breast masses in a pediatric population are benign and that sonography has the ability to differentiate among cystic, inflammatory, and solid masses.

The evaluation of hepatic diseases in children is often a multimodality process, requiring multiple imaging tests to determine the cause and extent of an abnormality. Ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) have distinct roles to play in the evaluation of hepatic disease in children. This article addresses the hepatic and biliary lesions that are unique or more common in children and describes their cross-sectional imaging characteristics. In addition, the techniques and protocols for US, CT, and MRI are reviewed.

Autosomal dominant polycystic disease with associated arachnoid cysts and subdural cystic hygroma requiring shunting

Posttransplantation lymphoproliferative disorder (PTLD) is a condition in patients who receive transplants in which chronic immunosuppression leads to an unregulated expansion of lymphoid cells; the condition ranges from hyperplasia to malignant lymphoid proliferation. Risk factors affecting the incidence of PTLD include allograft type, Epstein-Barr virus infection, and immunosuppression. In this article, we review the clinical, histopathologic, and imaging features of PTLD in children. Because PTLD can affect nearly any organ system, a wide variety of clinical manifestations is possible. The heterogeneous nature of the disease is also reflected on imaging studies. The goals of imaging in patients with PTLD are to detect disease, guide biopsy, and direct appropriate follow-up imaging rather than to establish a specific diagnosis. Because the clinical and imaging manifestations of PTLD are nonspecific and are not reliably predictive of histopathologic subtype, tissue biopsy is necessary for final diagnosis.

To study the appearance and distribution of posttransplantation lymphoproliferative disorder (PTLD) at abdominal computed tomography (CT).The authors retrospectively analyzed pretreatment abdominal CT scans in 51 patients (mean age, 36 years) with PTLD after solid organ transplantation. All diagnoses were proved at either abdominal (n = 26) or extraabdominal (n = 25) pathologic examination. Presence or absence of abdominal involvement, appearance and distribution of disease, and association with abdominal symptoms were all analyzed.CT scans were abnormal in 36 of the 51 patients (71%). Fifteen patients (29%) had no CT, clinical, or pathologic evidence of abdominal involvement. Of the 36 patients with abdominal PTLD at CT, 22% had lymph node enlargement, 28% splenic involvement, and 81% extranodal or extrasplenic involvement. Extranodal abdominal sites included liver (53%), small bowel (25%), kidney (17%), mesentery (14%), adrenal gland (8%), abdominal wall (8%), colon (6%), stomach (3%), and gallbladder (3%). Frequency of abdominal involvement was greater for heart and liver transplant recipients (94%) than for lung and kidney transplant recipients (58%) (P.01). Seventeen of 36 patients (47%) with abdominal PTLD had no evidence of extraabdominal disease.Extranodal involvement is more common than splenic or nodal involvement in patients with abdominal PTLD. The presence of such findings in a patient after transplantation strongly suggests the diagnosis of PTLD and warrants aggressive evaluation.

Little is known about the correlation between the location and size of cerebral infarction in children and neuropsychologic deficits. We related lesion location and volume on magnetic resonance exams to neuropsychologic performance in 28 children with cerebral infarcts due to sickle cell disease. Seventeen healthy siblings served as a comparison group. Children with anterior cerebral infarcts (n = 7) showed deficits in attention and executive skills, whereas children with more widespread cerebral infarcts (n = 18) showed additional deficits in spatial skills. The volume of cerebral infarction was associated with spatial and language performance, but minimally related to performance in other cognitive domains. The location and volume of cerebral infarction are both important for defining the type and magnitude of cognitive sequelae in childhood stroke.