A comparison between ultrasonography and single-phase computed tomography for preoperative assessment of solid abdominal tumors in children

ObjectiveThis study aimed to estimate the performance of single-phase-enhanced computed tomography and ultrasonography examinations in the preoperative evaluation of solid abdominal tumors and their relationship with relevant adjacent structures in children.MethodsThis retrospective study included 50 pediatric patients with malignant solid abdominal tumors treated with surgical resection between 2009-2017. Preoperative computed tomography and ultrasonography were compared to operative findings (gold standard) in the diagnosis of invasion or encasement of adjacent structures. Accuracy, sensitivity, specificity, and positive and negative predictive values were evaluated.ResultsRenal (20.4%) and neuroblastic (19.4%) tumors were the most common. Complete surgical resection with negative margins was achieved in 44 (88%) patients. The comparison between single-phase-enhanced computed tomography and ultrasonography findings showed the following results: sensitivity = 90.3% vs 86.6%, specificity = 86.8% vs 94.6%, negative predictive value = 95.3% vs 94.4%, positive predictive value = 75.3% vs 86.9%, and accuracy = 87.9% vs 92.2%. The correlation (kappa index) between computed tomography and ultrasonography examinations was 0.72 (p < 0.001). In 14% (7/50) of the patients, the invasion of adjacent structures was diagnosed by ultrasonography but not by computed tomography (1 patient had 2 invaded structures).ConclusionUltrasonography can be considered a complementary method to single-phase-enhanced computed tomography in the preoperative evaluation of children with an abdominal tumor. The present study showed that ultrasonography and single-phase-enhanced computed tomography each possess a high accuracy in the preoperative planning of resection of solid abdominal tumors in children. Thus, it seems that the combination of both imaging methods would be enough for the evaluation of most abdominal tumors in the pediatric population.     

Chest computed tomography in children

This article describes the use of computed tomography for the evaluation of pediatric patients with a variety of chest diseases. Indications for chest CT, constraints of technical factors on the study, and analysis of the benefits of CT examination versus risks will also be discussed.     

Ultrasonography and computed tomography for diagnosis and follow-up of pelvic rhabdomyosarcomas in children

The authors report 18 cases of pelvic rhabdomyosarcomas in children examined at presentation and followed on US and CT. There were 11 boys, 7 girls; tumor location was bladder, prostate or uterus in 12, perineum in 4, buttock in 2. US is good to define tumoral extension within the bladder CT is better to delineate the extension outside the bladder and regional spread to iliac nodes. CT is the only useful examination for perineal tumors. During chemotherapy US can be frequently repeated to appreciate tumoral regression and to give measurement of the mass. Preoperative CT should be performed when tumoral regression seems sufficient to permit complete tumoral excision without pelvic exanteration. Correlation between US and CT and surgical findings proved to be good. US and CT are also very useful in the follow-up when the child has finished treatment as it can demonstrate a local recurrence before clinical symptoms appear. However, post-surgical and post-radiation changes may be difficult to recognize. These aspects are discussed.     

Dual-source computed tomography coronary artery imaging in children

Pediatric Radiology - Computed tomography (CT) has a well-established diagnostic role in the assessment of coronary arteries in adults. However, its application in a pediatric setting is still...     

Liver volume in children measured by computed tomography

Liver volume was measured by computed tomography in 54 children and young adults with no history of liver disease. Their ages ranged from 10 days to 22 years. The volume was calculated as follows: (1) the edges of the liver were traced on each scan image and the area was calculated by computer; (2) the areas were summed and multiplied by the scan interval in centimeters. The mean liver volume (± SD) was 178.2 ± 81.9 cm³ in infants (less than 12 months old) and 1114.3 ± 192.9 cm³ in adolescents (more than 16 years old). The mean liver volume in relation to body weight (± SD) was 34.1 ± 5.5 cm³/kg in infants and 20.2 ± 3.1 cm³/kg in adolescents. In general, liver volume increases rapidly in infants, gradually in schoolchildren, and not at all in adolescents. Volumetry might be clinically useful for evaluating the liver function in children and determining the graft size in liver transplantation. Received: 6 November 1995 Accepted: 22 January 1996     

Radiation risk to children from computed tomography

Imaging studies that use ionizing radiation are an essential tool for the evaluation of many disorders of childhood. Ionizing radiation is used in radiography, fluoroscopy, angiography, and computed tomography scanning. Computed tomography is of particular interest because of its relatively high radiation dose and wide use. Consensus statements on radiation risk suggest that it is reasonable to act on the assumption that low-level radiation may have a small risk of causing cancer. The medical community should seek ways to decrease radiation exposure by using radiation doses as low as reasonably achievable and by performing these studies only when necessary. There is wide agreement that the benefits of an indicated computed tomography scan far outweigh the risks. Pediatric health care professionals' roles in the use of computed tomography on children include deciding when a computed tomography scan is necessary and discussing the risk with patients and families. Radiologists should be a source of consultation when forming imaging strategies and should create specific protocols with scanning techniques optimized for pediatric patients. Families and patients should be encouraged to ask questions about the risks and benefits of computed tomography scanning. The information in this report is provided to aid in decision-making and discussions with the health care team, patients, and families.     

Three-dimensional computed tomography for detection of tracheobronchial foreign body aspiration in children

Foreign body aspiration (FBA) into the tracheobronchial tree is a frequent and serious cause of respiratory problems in children. Chest X-ray (CXR) is often inaccurate in diagnosing FBA when the object is radiolucent. Three-dimensional computed tomography (CT) is a noninvasive technique that can detect the narrowing of the airway resulting from the presence of a foreign body. We conducted a retrospective study comparing the performance of CT scan and CXR in the diagnosis of FBA. Eleven patients (mean age 2.1 years) with a history suggestive of foreign body aspiration were examined by three-dimensional chest CT and CXR during the study. The presence of foreign bodies was confirmed and they were removed by rigid or flexible bronchoscopy under general anesthesia. Foreign body aspiration (FBA) was detected in all the 11 patients by CT scan (sensitivity, 100%), but CXR of three of the patients showed no evidence of FBA (sensitivity, 72.7%). The foreign bodies were located in the right main bronchus (n = 4), the left main bronchus (n = 5), and the trachea (n = 2). The mean length of hospital stay was 3.8 days. In our study, three-dimensional chest CT scan was more sensitive than CXR in detecting the presence of aspirated foreign bodies in children. The superior sensitivity and short time required for CT should help to reduce delays in diagnosis. These benefits may prompt further studies to determine whether CT could be used to reduce the number of unnecessary bronchoscopies performed in children being evaluated for FBA.     

Ultrasonography and computed tomography for diagnosis and follow-up of biliary duct rhabdomyosarcomas in children

The authors report eight cases of biliary duct rhabdomyosarcoma in children, examined by US and CT. There were five boys and three girls, aged 2 to 17 years. At presentation, US demonstrates the tumor mass within the liver or the hepatic hilum; it allows measurement of it and defines the relationship with portal vessels, biliary tract and other important structures. CT complements the US evaluation and determines operability. As US and CT cannot assess the histological origin of the tumor, a biopsy is mandatory before treatment. If complete surgical excision does not seem possible, percutaneous biopsy is preferrable to incomplete excision and its possible complications. During the follow-up period, US can be repeated to measure tumor regression under chemotherapy. After surgery, CT seems preferable because of gas interposition. Both US and CT proved to be valuable for the early detection of local recurrence. The prognosis of these tumors remains bad. However, with more aggressive and hopefully more efficient chemotherapy a precise evaluation of the tumor extension by US and CT is very important. Surgery will then be performed only on localized tumors or on residual masses after chemotherapy.     

Measurements of cervical lymph nodes in children on computed tomography

Background

No normal measurements or specific size criteria have been described for cervical lymph nodes in children.

Objective

To determine the normal measurements of cervical lymph nodes in children on CT.

Materials and methods

We included 142 children (ages 1–17 years) who underwent cervical CT examination after high-energy trauma. We evaluated axial and coronal 2-mm reconstructions for lymph nodes at six cervical levels. For the largest lymph node at each level, we measured diameters in both the long and short axial axes and the long coronal axis.

Results

A total of 733 lymph nodes were measured in 142 children (62% boys, 38% girls). The greatest measured diameters were 14 mm for the short axis in the axial plane, 24 mm for the long axis in the axial plane and 28 mm for the long axis in the coronal plane. The Pearson correlation coefficient for age and lymph node size at Levels IV–VI was in the range of 0.19–0.47.

Conclusion

Lymph nodes with an axial short-axis diameter exceeding 15 mm for Level II and 10 mm for all other cervical levels are uncommon in otherwise healthy children.

     

Positron emission tomography/computed tomography (PET/CT) in children

Although PET imaging has been available for more than two decades, its use has greatly increased lately due to the advent of PET/CT, readily available sources of commercially supplied FDG, and mobile scanners. These features have enabled PET scanning to expand beyond select major university medical centers, with on-site cyclotron facilities to smaller institutions including free- standing children's hospitals. In these settings, imaging is generally limited to FDG, which suffices for most applications, with the majority of studies performed for tumor imaging. FDGI is being used for evaluation of many tumors in children, with its use in lymphoma being the most established. In lymphoma, it has proven quite useful in determining whether active tumor is present in residual masses following treatment, which may otherwise contain only residual fibrous tissue. For brain tumors, FDGI has some relation to tumor grade, although its more important role is distinguishing recurrent or residual tumor from the effects of treatment, particularly radiation necrosis. For neurological evaluation, interictal FDGI is helpful in localizing potential seizure foci for subsequent subdural EEG monitoring. Because of the relatively long uptake time of FDG, true ictal studies cannot be performed with FDG, and these remain within the domain of SPECT imaging of tracers such as Tc-99m HMPAO. Examinations utilizing radiopharmaceuticals other than FDG are significantly more limited in their availability and are limited to PET centers with on-site cyclotrons. However, these additional agents open the door to many additional studies, including more specific tumor-imaging agents of certain tumors such as neuroblastoma. Another neurotransmitter, F-18-fluoro-L-dopa, is of benefit outside of the central nervous system for evaluating infantile hyperinsulism. The use of PET/CT in children is increasing quickly, particularly FDGI imaging of tumors. It is expected that over the next few years, its role will become increasingly better defined.