CT utilization: the emergency department perspective

CT scan utilization in the pediatric emergency department (ED) has dramatically increased in recent years. This likely reflects the improved diagnostic capability of CT, as well as its wider availability. However, the utility of CT is tempered by the high radiation exposure to patients as well as cost. In this review we will consider the magnitude of changes in CT use in the pediatric ED, and we will examine some of the driving forces behind these increases. In addition, we will consider strategies to limit growth in CT scan utilization or even result in reductions in CT use in the future. These strategies include better physician and patient education, application of existing clinical decision rules to reduce CT utilization and development of new rules, technical alterations in CT protocols to reduce per-exam exposures, use of alternative imaging modalities such as US and MRI that do not expose patients to ionizing radiation, and expanded use of clinical observation in place of immediate diagnostic imaging. Reform of liability laws might alleviate another driving force behind high CT utilization rates. Protocols must be designed to maximize patient safety by limiting radiation exposures while preserving rapid and accurate diagnosis of time-sensitive conditions.     

Urologic findings on computed tomography of the abdomen and pelvis in a pediatric population

Objectives(1) Determine the number of urologic conditions diagnosed by computed tomography (CT) in children in the emergency department setting. (2) Identify which diagnoses were incidental. (3) Determine how often there was urologic follow-up by a local pediatric urologist.Patients and methodsWe reviewed the charts and radiologist interpretations of all CT scans of the abdomen and pelvis performed within 2 days of admission via our emergency department from July 2007 to June 2009. Patients were included if the diagnosis was new. If a urologic finding was noted on final read, the CT was re-examined by one of our urologists to verify the finding.ResultsAmong 2991 CT scans (one CT scan per patient), there were 213 (7%) new urologic findings: 124 were incidental; 144 patients (68% of patients with urologic findings) did not receive follow-up. Renal abnormalities were present in 127. The most common finding was renal cyst (69 patients). Ureteral abnormalities were present in 47. The most common ureteral finding was hydroureteronephrosis (40). Other anomalies identified included bladder (7) and scrotal (14) abnormalities, stones (13), and adrenal lesions (5).ConclusionMany urologic diagnoses are revealed during CT scans of the abdomen and pelvis. The majority are cysts, hydroureteronephrosis, and pyelonephritis. Many incidental findings have also been revealed in the emergency department setting.     

Lung ultrasound for detecting pneumothorax in injured children: preliminary experience at a community-based Level II pediatric trauma center

Background

Ultrasound (US) has been used in the adult trauma population with reported moderate to high sensitivities, but data are scarce in the pediatric trauma population.

Objective

The purpose of this study was to specifically examine the sensitivity and specificity of one lung US methodology (single-point anterior exam) in the pediatric trauma population when compared to chest radiography or CT.

Materials and methods

We conducted a retrospective review of pediatric trauma patients who received lung US as an extension of the focused assessment with sonography for trauma (FAST) exam. We compared lung US findings with chest radiography and CT scans.

Results

Two hundred twenty-six pediatric trauma patients underwent lung US exam with confirmatory exams; 11 pneumothoraces (4.8%) were observed. Of those 11, 6 were evaluated as false negatives on the lung US. Analyses resulted in 45.5% sensitivity, 98.6% specificity and 96.0% accuracy. Pneumothoraces undetected by lung US were small and apical and were likely not observed because of their size and location. None of the false negatives required intervention. All true positives were associated with lung contusions.

Conclusion

Pneumothorax is less common in the pediatric than the adult trauma population, and when encountered in children pneumothorax is often occult and might be associated with lung contusions. Existing evidence supports the usefulness of chest US in detecting pneumothorax in adults and suggests that it can be translated to injured children. However, our findings suggest that the sensitivity of lung US as a single-point anterior exam extension of the FAST exam might not be as reliable in the pediatric trauma population as in adults. Other methodologies using lung US might improve sensitivity.

     

Geographic Variation in Acute Pediatric Mental Health Utilization

ObjectiveTo identify locations with higher need for acute pediatric mental health (MH) interventions or services and describe these communities’ socio-demographic characteristics.MethodsThis single-center retrospective study included patients 5 to 18 years old with an emergency department (ED) or hospital admission between 2017 and 2019 for a primary known MH diagnosis or symptoms. We extracted visit data from the electronic medical record, mapped patients to their home census tract, calculated normalized visit rates by census tract, and performed spatial analysis to identify nonrandom geographic clusters and outliers of high utilization. Census tract utilization rates were stratified into quartiles, and socioeconomic and demographic characteristics obtained from the US Census Bureau were compared using analysis of variance, chi-square tests, and multivariable analysis.ResultsThere were 10,866 qualifying visits across 617 census tracts. ED and hospital admission rates ranged from 2.7 to 428.6 per 1000 children. High utilization clusters localized to neighborhoods with lower socioeconomic status (p < .05). Southern regions with high utilizers were more likely to have fewer children per neighborhood, higher rates of teen births, and lower socioeconomic status. Multivariate analysis showed regions with high utilizers had fewer children per neighborhood, lower median household income, and more families that lacked computer access.ConclusionED and hospital utilization for pediatric MH concerns varied significantly by neighborhood and demographics. Divergent social factors map onto these locations and are related to MH utilization. Leveraging geography can be a powerful tool in the development of targeted, culturally tailored interventions to decrease acute pediatric MH utilization and advance child MH equity.     

Safety of repeated hyperpolarized helium 3 magnetic resonance imaging in pediatric asthma patients

Background

Hyperpolarized helium 3 magnetic resonance imaging (³He MRI) is useful for investigating pulmonary physiology of pediatric asthma, but a detailed assessment of the safety profile of this agent has not been performed in children.

Objective

To evaluate the safety of ³He MRI in children and adolescents with asthma.

Materials and methods

This was a retrospective observational study. ³He MRI was performed in 66 pediatric patients (mean age 12.9 years, range 8–18 years, 38 male, 28 female) between 2007 and 2017. Fifty-five patients received a single repeated examination and five received two repeated examinations. We assessed a total of 127 ³He MRI exams. Heart rate, respiratory rate and pulse oximetry measured oxygen saturation (SpO₂) were recorded before, during (2 min and 5 min after gas inhalation) and 1 h after MRI. Blood pressure was obtained before and after MRI. Any subjective symptoms were also noted. Changes in vital signs were tested for significance during the exam and divided into three subject age groups (8–12 years, 13–15 years, 16–18 years) using linear mixed-effects models.

Results

There were no serious adverse events, but three minor adverse events (2.3%; headache, dizziness and mild hypoxia) were reported. We found statistically significant increases in heart rate and SpO₂ after ³He MRI. The youngest age group (8–12 years) had an increased heart rate and a decreased respiratory rate at 2 min and 5 min after ³H inhalation, and an increased SpO₂ post MRI.

Conclusion

The use of ³He MRI is safe in children and adolescents with asthma.

     

18F-2-fluoro-2-deoxyglucose uptake in white adipose tissue on pediatric oncologic positron emission tomography (PET)/computed tomography (CT)

Background

Altered biodistribution of [F-18]2-fluoro-2-deoxyglucose (FDG) is sometimes encountered in pediatric patients undergoing chemotherapy for lymphoma on post-induction positron emission tomography (PET) imaging. A characteristic pattern of increased FDG uptake in white adipose tissue can be seen, particularly in the buccal regions, body wall and gluteal regions, with a shift of radiotracer away from the blood pool and liver. This altered biodistribution has been attributed to effects of corticosteroids in pediatric and adult patients and is important to recognize because of its potential for limiting the diagnostic quality of the PET scan and interfering with therapeutic response assessment.

Objective

In contrast to the well-known metabolically active brown fat seen on up to one-third of pediatric PET scans, white fat is usually non-metabolically active. We sought to determine the incidence of altered distribution of FDG in subcutaneous white adipose tissue in pediatric patients undergoing PET imaging and to assess the association with corticosteroid use.

Materials and methods

We reviewed the medical records and imaging for four children in whom altered biodistribution in white adipose tissue was present on post-induction FDG PET/CT, identified during routine clinical practice. All four were receiving corticosteroids as part of their chemotherapy. We then retrospectively reviewed oncology FDG PET/CT scans over a 2-year period (1,361 scans in 689 patients) to determine the incidence of uptake in white fat by qualitative visual assessment. In the children identified with altered biodistribution, we measured maximum standard uptake value (SUV_max) and mean standard uptake value (SUV_mean) in areas of subcutaneous white fat, the buccal regions, body wall or gluteal soft-tissue regions, liver and blood pool. We reviewed all medical records, including medication lists. We summarize the relevant clinical and imaging findings of 13 pediatric patients, including the 4 index patients.

Results

We determined the incidence of FDG uptake in white fat to be rare, found in 9 of 1,361 (0.6%) PET scans performed for pediatric cancer evaluation. FDG uptake was increased in subcutaneous adipose tissue, particularly in the buccal regions, body wall and gluteal regions, with a shift of radiotracer away from the blood pool and liver. The degree of increased uptake in peripheral white fat varied from marked to mild, and the biodistribution was distinct from that of brown adipose tissue. Children with this altered biodistribution were uniformly receiving corticosteroids as part of induction treatment for their cancer, and these findings were only identified on post-induction PET/CT. Follow-up PET/CT documented resolution of this effect after treatment with corticosteroids ceased.

Conclusion

Our findings support the current understanding that characteristic uptake of FDG in white adipose tissue is mediated by corticosteroid effect. Although this altered biodistribution is rare (<1% of PET scans) it could impair the diagnostic quality of the scan, affecting image interpretation, and should be recognized when present.

     

Trends in CT scan rates in children and pregnant women: teaching,private, public and nonprofit facilities

Background

Radiation exposure from medical sources now equals or exceeds that from natural background sources, largely attributable to a 20-fold increase in CT use since 1980. Increasing exposure to children and fetuses is of most concern due to their heightened susceptibility. More recently, CT use may be leveling or decreasing, but it is unclear whether this change is widespread or varies by type of institution.

Objective

We sought to characterize trends in CT utilization in California hospitals and emergency departments among children and pregnant women, looking at different types of facilities, such as teaching, private, public and nonprofit institutions.

Materials and methods

We examined frequency of CT examinations by year from 229 facilities reporting CT usage in routinely collected California statewide data for 2005–2012. We modeled trends overall and by facility type.

Results

CT scans for pediatric and pregnant patient visits in the emergency department increased initially, then started to decline after 2008. Among hospital admissions, rates declined or leveled after 2005. In the emergency department, CT rates varied between types of facilities, with teaching hospitals reducing use sooner and more sharply than other types of facilities.

Conclusion

CT utilization in California among children and pregnant women has begun to level or decline. Still, population exposure remains at historically high levels, warranting consideration of potential public health implications. Further examination of reasons for trends among hospital types, particularly how teaching hospitals have reduced rates of CT utilization, may help identify strategies for CT reduction without compromising patient care.     

Assessment of general emergency medicine physicians’ medical education regarding management of pediatric emergencies in western Normandy,France

ObjectivesGeneral emergency medicine physicians sometimes have to deal with acute management of pediatric emergencies. The objectives of this study were to assess the pediatric medical education background of emergency physicians, how often they encounter pediatric emergencies, as well as the knowledge and organizational gaps regarding the management of children in general emergency departments.MethodsA survey was conducted from March 25 to June 25, 2017, by emailing an anonymized questionnaire to all senior emergency physicians of the 22 general emergency departments of western Normandy public hospitals.ResultsA total of 81 responses were analyzed. In all, 83% percent of respondents had previously worked in a pediatric department. In total, 90% of the respondents reported caring for children within their emergency department and 93% out-of-hospital (100% of them during primary interventions and 39% during secondary interventions such as inter-hospital transfers). Fourteen percent of the respondents considered that the pediatric medical education they received was adapted to their current practice, while 73% reported experiencing difficulties during management of pediatric emergencies (technical difficulties, unsuitable material and therapeutics, relational problems, personal apprehension, disease- or age-specific difficulties, especially with children under the age of 2–3 years).ConclusionMost general emergency physicians report caring for children despite a lack of medical education in pediatrics. Pediatric medical education as well as collaborations between general practitioners and specialized pediatric teams should be enhanced to better match the needs of general emergency departments and improve the quality of primary and acute care for children.     

Management of children with nonfebrile seizures in the emergency department

BackgroundChildren with seizures are often referred to the emergency department where they are typically evaluated by a physician with limited knowledge of pediatric epileptology and undergo a costly and extensive work-up that contributes little to the final decision.AimThe aim of this study was to examine the medical management of children with nonfebrile seizures in the emergency department and to define the potential role of the neurology clinic in this context.Materials and methodsThe files of 85 children who made 104 visits to the emergency department of a pediatric tertiary hospital for nonfebrile seizures were retrospectively reviewed.ResultsAverage age was 7.5 years. Blood tests were performed in almost all visits; a minority also involved the use of brain scans and electroencephalography. A neurologist was consulted in about half the visits. Only electroencephalography and neurologic consultation contributed significantly to the final decision. Hospitalization was recommended in 71% of cases, but it was usually short term and not accompanied by significant changes in the management.ConclusionIn children with nonfebrile seizures, a problem-oriented approach including only the necessary work-up (e.g. electroencephalography) with neurologist consultation can potentially decrease the inpatient load and lower health care costs, while sparing patients unnecessary tests.     

Differences in Frequency of Visits to Pediatric Primary Care Practices and Emergency Departments by Body Mass Index

ObjectivesTo examine differences in utilization across health care settings among children by body mass index (BMI) categories to help identify opportunities for interventions.MethodsA retrospective study was conducted using 1 year of electronic health records following an index primary care visit for children 3 to 17 years old in 2016. Index visits occurred at >40 pediatric practices affiliated with a Northeastern health system. Using normal BMI as a reference group, we examined the extent to which children's BMI percentile categories were associated with primary care visits, emergency department (ED) visits, hospitalizations, and ED visit acuity. Age, sex, race/ethnicity, and insurance status were used as covariates.ResultsOf those with biologically plausible values for height and weight (n = 30,352), the prevalences of overweight, obesity, and severe obesity were 16.3%, 12.4%, and 5.7%, respectively. Children outside of the normal BMI range made more primary care visits; however, relative patterns of ED utilization were not consistent. Children with obesity versus normal BMI were less likely to have ED visits of high acuity. Risk of hospitalization was higher among children with overweight or severe obesity.ConclusionsChildren's BMI categories were associated with health care utilization, specifically primary care visits, ED visits, and hospitalizations. Further investigation is needed to explore the drivers of these differences in utilization, such as the impact of stigma and perceived weight bias on care-seeking patterns, and to examine the role of settings outside of primary care in pediatric weight management.     

Text2Breathe: Text-Message Intervention for Parent Communication and Pediatric Asthma

ObjectiveMobile health technology offers promise for reducing disparities in pediatric asthma care and outcomes by helping parents more effectively communicate with their children's primary care providers and manage their children's asthma. This study tested the impact of a text messaging program on emergency department utilization and asthma morbidity.MethodsA randomized controlled trial enrolled 221 parents of Medicaid-insured children visiting the emergency departments of 2 urban children's hospitals in the Pacific Northwest for an asthma-related concern between September 2015 and February 2019. Standardized surveys were administered to parents at baseline and 12 months later to assess the primary outcomes of emergency department utilization and morbidity as well as primary care utilization, parent communication self-efficacy, and asthma self-management knowledge. The intervention group received brief in-person education on partnering with primary care providers, followed by 3 months of educational text messages.ResultsParticipants were mostly female, English speakers, of minority race and ethnicity, and living below 200% of the federal poverty level. Negative binomial and linear regressions indicated no significant group differences in annual number of emergency department visits, morbidity, parent communication self-efficacy, or asthma self-management knowledge at 12 months’ follow-up, adjusting for baseline covariates. Average annual rate of primary care visits for asthma was 35% higher in the intervention group compared to control group at follow-up (95% confidence interval 1.03–1.76, P = .03).ConclusionsThis parent-focused text message intervention did not impact emergency department utilization or asthma morbidity; however, results suggest its potential for enhancing use of primary care for management of pediatric chronic conditions.     

Initiating a hospital-wide pediatric sedation service provided by emergency physicians

Advanced diagnostic procedures, imaging studies, and therapeutic procedures have combined to substantially increase the need for pediatric sedation. The objective of this study is to describe the initiation of a hospital-wide (nonemergency department) pediatric deep sedation service provided by pediatric emergency physicians. This article describes a consecutive cohort of pediatric patients undergoing deep sedation provided by a new hospital sedation service (excluding the emergency department). The results of 133 pediatric deep sedations are described. Propofol was used for most sedations. Mean infusion times were 55 minutes for MRI scans and 13 minutes for heme-oncology procedures. The risk of adverse events was low. This case series of pediatric deep sedation patients describes the initiation of a hospital-wide pediatric sedation service utilizing pediatric emergency physicians, which has resulted in improved patient care, and improved financial performance of several hospital units. The risk of adverse events is low if proper precautions are taken.     

Barbiturates

Sedation remains the most important, and sometimes the most difficult part of diagnostic or therapeutic procedures in children. Today, computed tomography (CT) scan and magnetic resonance imaging, (MRI) are widely used in the evaluation of pediatric disease; and the need for safe and effective sedation practice has grown. Pentobarbital, thiopental, and methohexital are 3 barbiturates that have gained popularity in the pediatric emergency department for sedation Pentobarbital II has been used With great success when sedation is required for unnllainful procedures in the emergency department setting Thiopental was used in the early 1980s but lost popularity in the 1990s. Methohexital because of its ultrashort-acting properties, has gained popularity for use in painful (eg, fracture reduction, laceration repair) and nonpainful procedures (eg, CT scanning, MRI). In this article, each drug is discussed for routes of administration, side effects. contraindications, and overall success rates.     

Imaging in acute abdomen

Objective The present study aims at establishing the exact role and limitation of ultrasound in pediatric acute abdomen.Methods Fifty children less than 14 years of age presenting with acute abdomen were evaluated by US and other imaging modalities. The mean age of presentation was 312 years. Maximum number of cases were seen in less than two years of age. There were 17 cases of intussusception with US sensitivity and specificity of 88.2% and 100% respectively and positive and negative predictive values of 100% and 94.5% respectively. There were 13 cases of appendicitis. US was diagnostic in 11 with sensitivity and specificity of 91.6% and 97%; the positive and negative predictive values were 91.6% and 97% respectively.Results : There were two cases each of congenital bands, adhesive intestinal obstruction, malrotation of bowel with volvulus, incarcerated inguinal hernia, hypertrophic pyloric stenosis, duplication cyst and pseudopancreatic cyst, one case each of trichobezoar, Meckel’s diverticulum, ureteric calculus and worms as a cause of intestinal obstruction. The sensitivity of US for diagnosing specific cause of acute abdomen was found to be 77.5%. The main limitation of US was in the diagnosis of acute intestinal obstruction such as congenital bands and adhesions.Conclusion. US should now be considered as imaging modality of choice in pediatric acute abdomen. However, at times, plain radiography, conventional contrast studies and CT may be vital to reach the true diagnosis     

Bowel ultrasound measurements in healthy children — systematic review and meta-analysis

Background

Ultrasound (US) is a noninvasive method of assessing the bowel that can be used to screen for bowel pathology, such as Inflammatory Bowel Disease, in children. Knowledge about US findings of the bowel in healthy children is important for interpreting US results in cases where disease is suspected.

Objective

To assess the bowel wall thickness in different bowel segments in healthy children and to assess differences in bowel wall thickness among pediatric age categories.

Materials and methods

We conducted a systematic search in the PubMed, Embase, Cochrane, and CINAHL databases for studies describing bowel wall thickness measured by transabdominal US in healthy children. We excluded studies using contrast agent. We calculated the pooled mean and standard deviation scores and assessed differences among age categories (0–4 years, 5–9 years, 10–14 years, 15–18 years), first with analysis of variance (ANOVA) and further with subsequent Student’s t-tests for independent samples, corrected for multiple testing.

Results

We identified 191 studies and included 7 of these studies in the systematic review. Reported bowel wall thickness values ranged from 0.8 mm to 1.9 mm in the small bowel and from 1.0 mm to 1.9 mm in the colon. The mean colonic bowel wall thickness is larger in children ages 15–19 years compared to 0–4 years (range in difference: 0.3–0.5 mm [corrected P<0.02]).

Conclusion

The reported upper limit of bowel wall thickness in healthy children is 1.9 mm in the small bowel and the colon, and mean thickness increases slightly with age in jejunum and colon. These values can be used as guidance when screening for bowel-related pathology in children.

     

Imaging diagnosis of retroperitoneal ganglioneuroma in childhood

Purpose. To demonstrate the typical appearance of retroperitoneal ganglioneuromas on CT and MRI.¶Materials and methods. Retrospective analysis of diagnostic imaging (five CT scans, three MRI scans) in five children aged 3–15 years with the histological diagnosis of ganglioneuroma.¶Results. The scans showed large (maximum 11 cm diameter), round or oval tumours with sharply defined margins. Intraspinal tumour involvement occurred in two cases. Comparing CT with MRI, MRI was more accurate in defining the intraspinal involvement. The ganglioneuromas were hypodense on unenhanced CT and showed moderate enhancement with administration of contrast medium. In three patients, CT demonstrated tumour calcification with a disseminated speckled pattern. On T1-weighted MRI the tumours were homogeneous and hypointense, showing marked enhancement after gadolinium administration. On T2-weighted scans the tumours were hyperintense.¶Conclusion. At the time of diagnosis, retroperitoneal ganglioneuromas are generally large tumours that can be shown well by CT and MRI. The appearance on CT more readily suggests the diagnosis, but MRI is superior for documenting local or intraspinal tumour extension and lacks radiation load.     

Localized Langerhans’ cell histiocytosis of bone: treatment and follow-up in children

We report a case of Langerhans’ cell histiocytosis (LCH) involving the right scapula in a 4-year-old child. Because of progressive shoulder pain and immobility methylprednisolone was injected directly into the lesion under computed tomography (CT) guidance. Follow-up studies with magnetic resonance imaging (MRI) and ultrasound (US) revealed continuous ossification of the osteolytic lesion with healing after 6 months. Plain films and CT confirmed the healing process. We consider intralesional corticoid instillation a safe method when performed under CT guidance. For initial evaluation and follow-up, MRI and US yielded reliable results in comparison to plain films and CT, thus helping to reduce the radiation dosage in children.

     

Differences in Tonsillectomy Utilization by Race/Ethnicity,Type of Health Insurance,and Rurality

ObjectiveTonsillectomy is one of the most common pediatric surgical procedures. In previous decades, large geographic variation and racial disparities in its use have been reported. We aimed to compare contemporary rates of pediatric tonsillectomy utilization in the United States by child race/ethnicity, type of health insurance, and metropolitan/nonmetropolitan residence.MethodsWe performed a cross-sectional study using the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project State Ambulatory Surgery and Services Databases and State Inpatient Databases of 8 US states. We included all children aged <15 years who underwent tonsillectomy in 2013 to 2017. Annual population-level tonsillectomy rates across states and sociodemographic groups overall and by surgical indication were calculated using US Census data. Negative binomial regression models were used to compare rates between groups.ResultsIn all states evaluated, tonsillectomy utilization was higher in non-Hispanic white children than non-Hispanic black or Hispanic children, higher in publicly insured than privately insured children, and higher in children residing in nonmetropolitan areas as compared to metropolitan areas (all P < .05). Tonsillectomy use was highest among white children from nonmetropolitan areas, both overall and for each indication (all P < .05).ConclusionsTonsillectomy utilization is higher in US children who are white, publicly insured, and who live in nonmetropolitan areas. Future research should identify multilevel factors, such as those at the patient, family, primary care provider, otolaryngologist, health care delivery system, interpersonal and community levels, that explain these differences in utilization in order to improve the appropriateness and equity of tonsillectomy use in children.     

Radiological features of focal nodular hyperplasia of the liver in children

Background. Focal nodular hyperplasia (FNH) is an unusual hepatic tumour in children and should be distinguished from other hepatic lesions. Objective. To describe the imaging characteristics of FNH in children. Materials and methods. We examined five patients (three boys and two girls, mean age 9.4 years) with pathologically confirmed FNH. The diagnosis was obtained by tumour resection (n = 4) and percutaneous needle biopsy (n = 1). One patient with multiple FNHs showed recurrent lesions after tumour resection. All patients were studied with US (including colour and power Doppler US [n = 3]) and CT. Dynamic enhanced CT scans were available in three patients. MRI (n = 2) or coeliac angiography (n = 1) was performed in three patients. Results. Seven of eight FNH lesions in five patients were demonstrated by imaging. The average size of the lesions was 6.5 cm. Six lesions detected on US showed variable echogenicity with a central hyperechoic scar (n = 2). On Doppler examination, central or peripheral hypervascular areas were seen (n = 3). Six lesions detected on contrast-enhanced CT showed high attenuation (n = 4) or iso-attenuation (n = 2). On early phase scans, all the lesions (n = 3) showed high attenuation. Irregular linear or ovoid central scars were detected in two patients on CT. MR demonstrated three lesions in two patients, one of which had not been detected by US or CT. A central low signal intensity scar (n = 1) was seen on T2-weighted MRI. Coeliac angiography performed in one patient showed a hypervascular mass with homogeneous staining. Conclusion. FNH in children shows a wide spectrum of imaging findings on various radiological examinations and the typical central scar was not always seen on imaging studies. Dynamic enhanced CT obtained in the early phase and colour Doppler studies may be helpful in the diagnosis of FNH by allowing characterisation of tumour vascularity. FNH should be included in the differential diagnosis of liver mass in children. Received: 10 September 1997 Accepted: 17 April 1998