Computed tomography and radiation risks: what pediatric health care providers should know

Biological effects of low-dose radiation from computed tomography scanning

PURPOSE

With the widespread use of computed tomography (CT), the risks of low-dose radiation from CT have been increasingly highlighted. This study aims to illustrate the CT-induced biological effects and analyze the potential beneficial or harmful outcomes so as to provide radiologists with reasonable advice on CT usage.

MATERIALS AND METHODS

The related literature was analyzed according to the topics of stochastic effect, hereditary effect, deterministic effect, accumulative injuries, hormesis and adaptive response; population epidemiology data were also analyzed.

RESULTS

CT accounts for 9% of X-ray examinations and approximately 40-67% of medical-related radiation, the dose is within the range of low-dose radiation (LDR). Two opposite viewpoints exist nowadays regarding the biological effects of CT scanning: They are either harmful or harmless. Approximately 0.6% and 1.5% of the cumulative cancer risk could be attributed to diagnostic X-rays in the UK and Germany, respectively. The probability of CT scans induced-cancer is about 0.7% and CT angiography's risk is around 0.13%. It is estimated that approximately 29,000 cancers could be related to CT scans in the USA every year. Meanwhile, another investigation of 25,104 patients who underwent 45,632 CT scans in 4 years showed that the majority of CT-induced cancers were accidents rather than certainties of frequent CT scans.

CONCLUSION

Although the LDR effects of CT are still controversial, the current problems include the high frequency-use and abuse of CT scans, the increase of radiation dose and accumulative dose in high-accuracy CT, and the poor understanding of carcinogenic risks. The underlying biological basis needs further exploring and the ratio of risks and benefits should be considered.

Initial assessment and management of pediatric trauma patients

Injury is the leading cause of death and disability in children. Each year, almost one in six children in the United States require emergency department (ED) care for the treatment of injuries, and more than 10,000 children die from injuries. Severely injured children need to be transported to a facility that is staffed 24/7 by personnel experienced in the management of children, and that has all the appropriate equipment to diagnose and manage injuries in children. Anatomical, physiological, and emotional differences between adults and children mean that children are not just scaled-down adults. Facilities receiving injured children need to be child and family friendly, in order to minimize the psychological impact of injury on the child and their family/carers. Early recognition and treatment of life-threatening airway obstruction, inadequate breathing, and intra-abdominal and intra-cranial hemorrhage significantly increases survival rate after major trauma. The initial assessment and management of the injured child follows the same ATLS^® sequence as adults: primary survey and resuscitation, followed by secondary survey. A well-organized trauma team has a leader who designates roles to team members and facilitates clear, unambiguous communication between team members. The team leader stands where he/she can observe the entire team and monitor the “bigger picture.” Working together as a cohesive team, the members perform the primary survey in just a few minutes. Life-threatening conditions are dealt with as soon as they are identified. Necessary imaging studies are obtained early. Constant reassessment ensures that any deterioration in the child's condition is picked up immediately. The secondary survey identifies other injuries, such as intra-abdominal injuries and long-bone fractures, which can result in significant hemorrhage. The relief of pain is an important part of the treatment of an injured child.

Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective

PURPOSE

This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR™) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR™. Empirically derived dose reduction limits were established for ASiR™ for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence∕adulthood.

METHODS

Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%-100% ASiR™ blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR™ implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent∕adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR™ reconstruction to maintain noise equivalence of the 0% ASiR™ image.

RESULTS

The ASiR™ algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR™ reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR™ presented a more smoothed appearance than the pre-ASiR™ 100% FBP image. Finally, relative to non-ASiR™ images with 100% of standard dose across the pediatric phantom age spectrum, similar noise levels were obtained in the images at a dose reduction of 48% with 40% ASIR™ and a dose reduction of 82% with 100% ASIR™.

CONCLUSIONS

The authors' work was conducted to identify the dose reduction limits of ASiR™ for a pediatric oncology population using automatic tube current modulation. Improvements in noise levels from ASiR™ reconstruction were adapted to provide lower radiation exposure (i.e., lower mA) instead of improved image quality. We have demonstrated for the image quality standards required at our institution, a maximum dose reduction of 82% can be achieved using 100% ASiR™; however, to negate changes in the appearance of reconstructed images using ASiR™ with a medium to low frequency noise preserving reconstruction filter (i.e., standard), 40% ASiR™ was implemented in our clinic for 42%-48% dose reduction at all pediatric ages without a visually perceptible change in image quality or image noise.

A dose comparison survey in CT departments of dedicated paediatric hospitals in Australia and Saudi Arabia

AIM: To measure and compare computed tomography (CT) radiation doses delivered to patients in public paediatric hospitals in Australia and Saudi Arabia.

METHODS: Doses were measured for routine CT scans of the head, chest and abdomen/pelvis for children aged 3-6 years in all dedicated public paediatric hospitals in Australia and Saudi Arabia using a CT phantom measurement cylinder.

RESULTS: CT doses, using the departments’ protocols for 3-6 year old, varied considerably between hospitals. Measured head doses varied from 137.6 to 528.0 mGy_·cm, chest doses from 21.9 to 92.5 mGy_·cm, and abdomen/pelvis doses from 24.9 to 118.0 mGy_·cm. Mean head and abdomen/pelvis doses delivered in Saudi Arabian paediatric CT departments were significantly higher than those in their Australian equivalents.

CONCLUSION: CT dose varies substantially across Australian and Saudi Arabian paediatric hospitals. Therefore, diagnostic reference levels should be established for major anatomical regions to standardise dose.

Iterative image reconstruction for cerebral perfusion CT using a pre-contrast scan induced edge-preserving prior

Cerebral perfusion x-ray computed tomography (PCT) imaging, which detects and characterizes the ischemic penumbra, and assesses blood-brain barrier permeability with acute stroke or chronic cerebrovascular diseases, has been developed extensively over the past decades. However, due to its sequential scan protocol, the associated radiation dose has raised significant concerns to patients. Therefore, in this study we developed an iterative image reconstruction algorithm based on the maximum a posterior (MAP) principle to yield a clinically acceptable cerebral PCT image with lower milliampere-seconds (mA s). To preserve the edges of the reconstructed image, an edge-preserving prior was designed using a normal-dose pre-contrast unenhanced scan. For simplicity, the present algorithm was termed as 'MAP-ndiNLM'. Evaluations with the digital phantom and the simulated low-dose clinical brain PCT datasets clearly demonstrate that the MAP-ndiNLM method can achieve more significant gains than the existing FBP and MAP-Huber algorithms with better image noise reduction, low-contrast object detection and resolution preservation. More importantly, the MAP-ndiNLM method can yield more accurate kinetic enhanced details and diagnostic hemodynamic parameter maps than the MAP-Huber method.

Advances in functional X-ray imaging techniques and contrast agents

X-rays have been used for non-invasive high-resolution imaging of thick biological specimens since their discovery in 1895. They are widely used for structural imaging of bone, metal implants, and cavities in soft tissue. Recently, a number of new contrast methodologies have emerged which are expanding X-ray's biomedical applications to functional as well as structural imaging. These techniques are promising to dramatically improve our ability to study in situ biochemistry and disease pathology. In this review, we discuss how X-ray absorption, X-ray fluorescence, and X-ray excited optical luminescence can be used for physiological, elemental, and molecular imaging of vasculature, tumors, pharmaceutical distribution, and the surface of implants. Imaging of endogenous elements, exogenous labels, and analytes detected with optical indicators will be discussed.

Blunt head trauma in children in a community health care setting: outcomes and variables associated with the use of computed tomography

OBJECTIVE

To evaluate the incidence of clinically important traumatic brain injury (ciTBI) in children presenting to a community hospital setting and identified factors associated with computed tomography (CT) use.

STUDY DESIGN

Retrospective cohort study of consecutive children presenting with blunt head trauma to a community emergency department or clinic over 12 months. Logistic regression models were used to compare differences in characteristics between patients who received and did not receive CT scans.

RESULTS

Of 1007 patients, 62% male, age 14 days-18 years (270 <2 years, 737 ≥2 years), 189 (18%) had CT scans, 2 (0.2%) showed evidence of ciTBI on CT, 13 (1.3%) hospitalized, and none required neurosurgical intervention or died. Factors associated with CT use in patients ≥2 years: history of vomiting (OR 4.08, 95% CI 2.08-7.99, P < .001), change in behavior (OR 2.83, 95% CI 1.63-4.91, P < .001), headache (OR 3.4, 95% CI 1.87-6.16, P < .001), loss of consciousness (OR 2.83, 95% CI 1.38-5.8, P = .004), and abnormal neurologic examination (OR 26.18, 95% CI 2.26-303.05, P = .009). Patients were more likely to receive CT scans in community emergency departments than clinics (OR 7.04, 95% CI 2.40-20.65, P = .002).

CONCLUSION

Patients in our community hospital setting are at low risk of ciTBI. The clinical indicators used to determine the need for CT in patients with more significant mechanisms of injury to pediatric or academic centers may not apply to this group. Future studies are required to determine which clinical indications are significant in this setting.

Low-dose protocol for head CT in evaluation of hydrocephalus in children

Background:

A suspicion of ventriculo–peritoneal shunt failure is classified as the most common indication for CT in children with hydrocephalus. The main target of the study was to evaluate the diagnostic value of a low-dose protocol and to compare a total DLP received by patients in compared protocols.

Material/Methods:

Our retrospective analysis included 256 examinations performed in patients aged from 1 month to 18 years, with body mass ranging from 3 to 100 kg. The examinations were conducted in the years 2009–2011. A total number of 128 examinations were performed on the basis of the low-dose protocol and 128 according to a standard protocol using the Siemens SOMATOM Definition AS 128-slice scanner.

Results/Conlusions:

The analysis showed a full value of the diagnostic low-dose protocol with a simultaneous decrease of the total dose of DLP to the average of 40%.

Application protocol with lower mAs in assessing the causes of ventriculo-peritoneal shunt failure in children with hydrocephalus is coherent with the valid principles of radiation protection in pediatrics and reduces the total DLP while maintaining a very good diagnostic value.

Eight-second MRI scan for evaluation of shunted hydrocephalus

INTRODUCTION

Pediatric patients harboring shunts placed early in life are subjected to numerous radiographic studies during development of their central nervous system. Radiation is detrimental to these young patients. MRI avoids the risk of radiation but is thought more difficult due to the increased time a young patient must lie motionless during scan acquisition. Optimal radiographic interrogation would be quick, radiation-free, and allow adequate ventricular evaluation.

METHODS

We queried the electronic medical records system of the senior author (SE) for the terms "hydrocephalus" and "shunt malfunction." All patients currently younger than 18 years were included. In the last 5 years, pediatric patients have been evaluated in an office setting with a limited MRI sequence (T1 sagittal, T2 axial, T1 axial, and DWI) lasting a total of 178 s. In the event of significant motion artifact, the total sequence is abandoned and an 8-s T2 diffusion-weighted scan is performed.

RESULTS

Forty-four patients were included in the study (20 males, average age 10.4 yrs). Eighty-eight rapid acquisition scans were obtained. Adequate ventricular evaluation was performed without sedation in every case. In each instance where there was motion, the 8-s scan provided adequate ventricular evaluation.

CONCLUSION

Rapid acquisition MRI scanning avoids the deleterious cumulative effects of radiation in pediatric patients and allows adequate evaluation of the ventricles without the need for sedation.

Congenital lung lesions

Confusion, controversy, and uncertainty are all terms applicable to the diagnosis and management of congenital lung lesions both prenatally and postnatally. This review examines the current status of fetal diagnosis and treatment of these lesions; reviews the various classifications, including congenital cystic adenomatoid malformation/congenital pulmonary airway malformation, sequestrations, variants and hybrid lesions; discusses the risk of malignant transformation or misdiagnosis with pleuropulmonary blastoma; presents the arguments in favor and against resection of asymptomatic lesions, the timing of such resection, and the long-term pulmonary function after resection; and reviews the experience with thoracoscopic resection of congenital lung lesions.

Pulmonary embolism in children

Unlike in adults, pulmonary embolism (PE) is an infrequent event in children. It has a marked bimodal distribution during the paediatric years, occurring predominantly in neonates and adolescents. The most important predisposing factors to PE in children are the presence of a central venous line (CVL), infection, and congenital heart disease. Clinical signs of PE are non-specific in children or can be masked by underlying conditions. Diagnostic testing is necessary in children, especially with the lack of clinical prediction rules. Recommendations for tests are derived from adult studies with ventilation/perfusion (V/Q) scintigraphy being well established. There exists an increasing role for computerised tomography pulmonary angiography (CTPA) and magnetic resonance pulmonary angiography (MRPA). Thrombotic events in children are initially treated with unfractionated heparin (UFH) or low molecular weight heparin (LMWH). For the extended anticoagulant therapy LMWH or vitamin K antagonists can be used with duration of treatment recommendations extrapolated from adult data. Mortality rates for PE in children are reported to be around 10%, with death usually related to the underlying disease processes. Exact data about recurrence risk in children is unknown. Because of the difference in aetiology, presentation, diagnostic methods and treatment between adults and children further research is necessary to assess the validity of recommendations for children.

Complex pediatric cervical spine surgery using smaller nonspinal screws and plates and intraoperative computed tomography

OBJECT

The treatment of craniocervical instability in children is often challenging due to their small spine bones, complex anatomy, and unique syndromes. The authors discuss their surgical experience with 33 cases in the treatment of 31 children (≤ 17 years of age) with craniocervical spine instability using smaller nontraditional titanium screws and plates, as well as intraoperative CT.

METHODS

All craniocervical fusion procedures were performed using intraoperative fluoroscopic imaging and electrophysiological monitoring. Nontraditional spine hardware included smaller screw sizes (2.4 and 2.7 mm) from the orthopedic hand/foot set and mandibular plates. Twenty-three of the 33 surgical procedures were performed with intraoperative CT, which was used to confirm adequate position of the spine hardware and alignment of the spine.

RESULTS

The mean patient age was 9.5 years (range 2-17 years). Eleven children underwent a posterior C1-2 transarticular screw fusion, 17 had an occipitocervical fusion, and 3 had a posterior subaxial cervical fusion. The follow-up duration ranged from 9 to 72 months (mean 53 months). All children demonstrated successful fusion at their 3-month follow-up visit, except 1 patient whose unilateral C1-2 transarticular screw fusion required a repeat surgery before proper fusion was achieved. Of the 47 C1-2 transarticular screws that were placed, 13 were 2.4 mm, 15 were 2.7 mm, 7 were 3.5 mm, and 12 were 4.0 mm. Eighteen of the 47 C1-2 transarticular screws were suboptimally placed. Eleven of these misplaced screws were removed and redirected within the same operation because these surgeries benefitted from the use of intraoperative CT; 6 of the 7 remaining suboptimally placed screws were left in place because a second surgery for screw replacement was not warranted. The other suboptimally placed C1-2 screw was replaced during a repeat operation due to failure of fusion. Use of intraoperative CT was invaluable because it enabled the authors to reposition suboptimal C1-2 transarticular screws without necessitating a second operation.

CONCLUSIONS

Successful craniocervical fusion procedures were achieved using smaller nontraditional titanium screws and plates. Intraoperative CT was a helpful adjunct for confirming and readjusting the trajectory of the screws prior to leaving the operating room, which decreases overall treatment costs and reduces complications.

KERMA ratios in pediatric CT dosimetry

BACKGROUND

Patient organ doses may be estimated from CTDI values. More accurate estimates may be obtained by measuring KERMA (Kinetic Energy Released in Matter) in anthropomorphic phantoms and referencing these values to free-in-air X-ray intensity.

OBJECTIVE

To measure KERMA ratios (R(K)) in pediatric phantoms at CT.

MATERIALS & METHODS

CT scans produce an air KERMA K in a phantom and an air KERMA K(CT) at isocenter. KERMA ratios (R(K)) are defined as (K/K(CT)), measured using TLD chips in phantoms representing newborns to 10-year-olds.

RESULTS

R(K) in the newborn is approximately constant. For the other phantoms, there is a peak R(K) value in the neck. The median R(K) values for the GE scanner at 120 kV were 0.92, 0.83, 0.77 and 0.76 for newborns, 1-year-olds, 5-year-olds and 10-year-olds, respectively. Organ R(K) values were 0.91 ± 0.04, 0.84 ± 0.07, 0.74 ± 0.09 and 0.72 ± 0.10 in newborns, 1-year-olds, 5-year-olds and 10-year-olds, respectively. At 120 kV, a Siemens Sensation 16 scanner had R(K) values 5% higher than those of the GE LightSpeed Ultra.

CONCLUSION

KERMA ratios may be combined with air KERMA measurements at the isocenter to estimate organ doses in pediatric CT patients.

Computed tomography scanning in pediatric trauma: opportunities for performance improvement and radiation safety

BACKGROUND

Recently, pediatric CT scanning protocols have reduced radiation exposure in children. Because evaluation with CT scan after trauma contributes to significant radiation exposure, we reviewed the CT scans in children at both initial presentation at a non-pediatric facility and subsequent transfer to a level I pediatric trauma center (PTC) to determine the number of scans, body area scanned, radiation dosage, and proportion of scans at each facility.

METHODS

The trauma database was retrospectively reviewed for children aged 0 to 17 y initially evaluated for trauma at another facility and then transferred to our PTC for pediatric specialty care between January 2000 and December 2010.

RESULTS

A total of 1562 patients with 1335 CT scans were reviewed over an 11-y period. The majority of CT scans occur at the referring facility compared to the PTC in a ratio of 7:3. CT of the head was the most frequent scan obtained (52%), and 17.9% of CT scans were repeated at the PTC. Less than 1% of CT scans performed at the non-pediatric centers contained radiation dosage information, precluding analysis of radiation exposure.

CONCLUSIONS

The majority of CT scans for trauma occur at non-pediatric facilities, which demonstrates the need for referring facilities to perform optimal CT scans with the least amount of radiation exposure to the child. We believe this provides an opportunity for PTC performance improvement by facilitating the transfer of images and educating referring facilities about indications for CT scans, dosage amounts, and radiation reduction protocols.

Radiology residents' awareness about ionizing radiation doses in imaging studies and their cancer risk during radiological examinations

Objective

Imaging methods that use ionizing radiation have been more frequent in various medical fields with advances in imaging technology. The aim of our study was to make residents be aware of the radiation dose they are subjected to when they conduct radiological imaging methods, and of cancer risk.

Materials and Methods

A total of 364 residents participated in this descriptive study which was conducted during the period between October, 2008 and January, 2009. The questionnaires were completed under strict control on a one-to-one basis from each department. A χ²-test was used for the evaluation of data obtained.

Results

Only 7% of residents correctly answered to the question about the ionizing radiation dose of a posteroanterior (PA) chest X-ray. The question asking about the equivalent number of PA chest X-rays to the ionizing dose of a brain CT was answered correctly by 24% of residents; the same question regarding abdominal CT was answered correctly by 16% of residents, thorax CT by 16%, thyroid scintigraphy by 15%, intravenous pyelography by 9%, and lumbar spine radiography by 2%. The risk of developing a cancer throughout lifetime by a brain and abdominal CT were 33% and 28%, respectively.

Conclusion

Radiologic residents should have updated knowledge about radiation dose content and attendant cancer risks of various radiological imaging methods during both basic medical training period and following practice period.

Neurologic complaints in young children in the ED: when is cranial computed tomography helpful?

MAIN OBJECTIVE

The objective of this study is to describe the use of emergent head computed tomography (CT) in young children and ask in which circumstances scans contributed to immediate management.

METHODS

We reviewed electronic records of children, aged 1 month through 6 years, who received a head CT at a large suburban emergency department between February 2008 and February 2009. Age, sex, chief complaint, history, physical examination, indication for and results of head CT, red flags in history or physical examination, final disposition, and number of head CT scans performed to date were recorded. Abnormalities on CT scans were classified as significant or incidental, and subsequent interventions were documented.

RESULTS

Emergent head CTs were performed on 394 children. The most common indications were trauma, 65%; seizure, 11%; and headache, 6%. Computed tomographic abnormalities were found in 40% (154 children): 32 significant findings,104 incidental findings, and 22 preexisting abnormalities. Four children with significant findings required immediate intervention. They all had red flags in both history and physical examination, and 3 of 4 children had known preexisting pathology; 1 child had nonaccidental trauma. Only 1 child had a significantly abnormal CT with no identifiable red flags; this child was admitted for observation and was discharged within 24 hours. Approximately a third of children had no readily identifiable red flag for the CT scans that they received. Of note, 20% of the young children had received more than 1 head CT scan to date, and 6% had between 6 and 20 scans.

CONCLUSIONS

Every child in this sample who required emergency intervention had red flags on history and physical examination. The 35% of CT scans performed in young children without red flags did not contribute usefully to their acute management.

Lung ultrasonography of pulmonary complications in preterm infants with respiratory distress syndrome

AIM

To evaluate the diagnostic possibilities of lung ultrasonography (LUS) in detecting pulmonary complications in preterm infants with respiratory distress syndrome (RDS).

MATERIAL AND METHODS

A prospective study included 120 preterm infants with clinical and radiographic signs of RDS. LUS was performed using both a transthoracic and a transabdominal approach within the first 24 h of life, and, after that, follow-up LUS examinations were performed. In 47 detected pulmonary complications of RDS (hemorrhage, pneumothorax, pneumonia, atelectasis, bronchopulmonary dysplasia), comparisons between LUS and chest X-ray (CXR) were made. Also, 90 subpleural consolidations registered during LUS examinations were analysed. Statistical analysis included MANOVA and discriminant analysis, t-test, confidence interval, and positive predictive value.

RESULTS

In 45 of 47 instances the same diagnosis of complication was detected with LUS as with CXR, indicating a high reliability of the method in premature infants with RDS. The only two false negative findings concerned partial pneumothorax. The positive predictive value of LUS was 100%. A statistically significant difference of LUS findings between the anterior and posterior lung areas was observed in both right and left hemithoraces.

CONCLUSIONS

LUS enables the detection of pulmonary complications in preterm infants with RDS and has the potential to reduce the number of CXRs. The specific guidelines for its use should be provided in a more extensive study.

Trends in computed tomography utilization in the pediatric emergency department

OBJECTIVE

The purpose of this study was to determine the overall trend of computed tomography (CT) utilization in the pediatric emergency department (PED) from 2003 to 2010 and to determine trends categorized by common chief complaints.

METHODS

Electronic chart records at 2 tertiary care PEDs within a large pediatric health care system were reviewed from January 2003 through December 2010. The annual CT utilization rate, by anatomic location, was determined. Annual CT utilization rates were compared with alternative imaging trends for visits with chief complaints of head injury, seizure, and abdominal pain. Analysis was performed with linear regression.

RESULTS

There was no change in overall CT utilization from 2003 to 2010 (β 0.25, 95% confidence interval [CI] [-1.61 to 2.73]) or within anatomic subgroups. Head CT utilization for the chief complaints of seizure (β -0.97, 95% CI [-1.44 to -0.90]) and head injury (β -0.93, 95% CI [-1.71 to -0.73]) showed significant declines. Although there was no change in the abdominal CT utilization rate for abdominal pain, abdominal ultrasound utilization for abdominal pain significantly increased (β 0.89, 95% CI [0.25-0.79]).

CONCLUSIONS

Our data showed no overall increase in CT utilization through 2010. In areas where alternative non-radiation-based modalities were options, there were decreased CT trends and increased use of potential alternative non-radiation-based modalities. This is the first large PED cohort study to show a decrease in CT utilization in recent years in a regional pediatric referral center and may correlate with increased awareness of radiation risk in children.

Questioning the legitimacy of rigid bronchoscopy as a tool for establishing the diagnosis of a bronchial foreign body

OBJECTIVES

Rigid bronchoscopy (RB) is the principal method used for the extraction of a tracheo-bronchial foreign body (FB), but its use as a diagnostic tool implies a certain rate of negative exams, exposing the child to the risk of procedure and anesthesia-related complications. Technological progress has improved the accuracy and availability of non-invasive modalities, such as CT scan and fluoroscopy. Our aim is to review our experience in the routine use of bronchoscopy for a suspected FB aspiration, and evaluate the adequacy of our current attitude in light of these alternatives.

METHODS

We performed a retrospective review of cases where bronchoscopy was used in the management of a suspected airway FB, and analysis of the correlation between the clinical and radiological data and the bronchoscopy's results. In addition we reviewed the literature concerning the use of RB and alternative means of diagnosis such as CT scan, fluoroscopy and flexible bronchoscopy.

RESULTS

Thirty-two patients underwent bronchoscopy to rule out a FB aspiration under general anesthesia. No FB was found in 8 cases (25%). Cough and a history of choking were the most sensitive parameters (sensitivity 100% and 80% respectively), but had a low specificity. Stridor was the most specific sign (88% specificity), but was not sensitive. Chest radiography had 25% sensitivity, and 62.5% specificity. Flexible bronchoscopy changed the management in 22% of cases, sparing RB.

CONCLUSIONS

Basing the decision to perform RB solely on the clinical findings and chest radiography entails a 25% rate or more of negative exams. CT scan appears to be the most accurate non-invasive tool for ruling out the presence of a FB but its use cannot be systematic due to its complexity and the risks of exposure to radiation. Digital substraction fluoroscopy is a safe and simple mean to confirm the presence of air trapping generated by a bronchial obstruction, but it is not sensitive enough to definitively rule out a FB. We propose a stepwise approach using fluoroscopy or possibly flexible bronchoscopy under sedation, in order to reduce the number of negative RBs while restricting the use of the CT scan.

Radiation dose features and solid cancer induction in pediatric computed tomography

Over the past two decades technical advances and improvements have made computed tomography (CT) a valuable and essential tool in the array of diagnostic imaging modalities. CT uses ionizing radiation (X-rays) which may damage DNA and increase the risk of carcinogenesis. This is especially pertinent in pediatric CT as children are more radiosensitive and have a longer life expectancy than adults. The purpose of this paper is to review and elucidate the potential harmful effects of ionizing radiation in terms of solid cancer induction from pediatric CT scanning. In the light of scientific and technical developments, we will also discuss the possible strategies and ongoing efforts to reduce CT radiation exposure in pediatric patients. In this context, we will not ignore the fact that a well-justified CT scan may exceed its risk and have a favorable impact.

Multislice CT of the head and body routine scans: Are scanning protocols adjusted for paediatric patients?

PURPOSE

To investigate whether the multislice CT scanning protocols of head, chest and abdomen are adjusted according to patient's age in paediatric patients.

MATERIALS AND METHODS

Multislice CT examination records of paediatric patients undergoing head, chest and abdomen scans from three public hospitals during a one-year period were retrospectively reviewed. Patients were categorised into the following age groups: under 4 years, 5-8 years, 9-12 years and 13-16 years, while the tube current was classified into the following ranges: < 49 mA, 50-99 mA, 100-149 mA, 150-199 mA, > 200 mA and unknown.

RESULTS

A total of 4998 patient records, comprising a combination of head, chest and abdomen CT scans, were assessed, with head CT scans representing nearly half of the total scans. Age-based adjusted CT protocols were observed in most of the scans with higher tube current setting being used with increasing age. However, a high tube current (150-199 mA) was still used in younger patients (0-8 years) undergoing head CT scans. In one hospital, CT protocols remained constant across all age groups, indicating potential overexposure to the patients.

CONCLUSION

This analysis shows that paediatric CT scans are adjusted according to the patient's age in most of the routine CT examinations. This indicates increased awareness regarding radiation risks associated with CT. However, high tube current settings are still used in younger patient groups, thus, optimisation of paediatric CT protocols and implementation of current guidelines, such as age-and weight-based scanning, should be recommended in daily practice.

Biological effects and adaptive response from single and repeated computed tomography scans in reticulocytes and bone marrow of C57BL/6 mice

This study investigated the biological effects and adaptive responses induced by single and repeated in vivo computed tomography (CT) scans. We postulated that, through the induction of low-level oxidative stress, repeated low-dose CT scans (20 mGy, 2 days/week, 10 weeks) could protect mice (C57BL/6) from acute effects of high-dose radiation (1 Gy, 2 Gy). The micronucleated reticulocyte (MN-RET) count increased linearly after exposure to single CT scans of doses ranging from 20 to 80 mGy (P = 0.033). Ten weeks of repeated CT scans (total dose 400 mGy) produced a slight reduction in spontaneous MN-RET levels relative to levels in sham CT-scanned mice (P = 0.04). Decreases of nearly 10% in γ-H2AX fluorescence levels were observed in the repeated CT-scanned mice after an in vitro challenge dose of 1 Gy (P = 0.017) and 2 Gy (P = 0.026). Spontaneous apoptosis levels (caspase 3 and 7 activation) were also significantly lower in the repeated CT-scanned mice than the sham CT-scanned mice (P < 0.01). In contrast, mice receiving only a single CT scan showed a 19% elevation in apoptosis (P < 0.02) and a 10% increase in γ-H2AX fluorescence levels after a 2-Gy challenge (P < 0.05) relative to sham CT controls. Overall, repeated CT scans seemed to confer resistance to larger doses in mice, whereas mice exposed to single CT scans exhibited transient genotoxicity, enhanced apoptosis, and characteristics of radiation sensitization.

Evaluation of pneumonia in children: comparison of MRI with fast imaging sequences at 1.5T with chest radiographs

BACKGROUND

Although there has been a study aimed at magnetic resonance imaging (MRI) evaluation of pneumonia in children at a low magnetic field (0.2T), there is no study which assessed the efficacy of MRI, particularly with fast imaging sequences at 1.5T, for evaluating pneumonia in children.

PURPOSE

To investigate the efficacy of chest MRI with fast imaging sequences at 1.5T for evaluating pneumonia in children by comparing MRI findings with those of chest radiographs.

MATERIAL AND METHODS

This was an Institutional Review Board-approved, HIPPA-compliant prospective study of 40 consecutive pediatric patients (24 boys, 16 girls; mean age 7.3 years ± 6.6 years) with pneumonia, who underwent PA and lateral chest radiographs followed by MRI within 24 h. All MRI studies were obtained in axial and coronal planes with two different fast imaging sequences: T1-weighted FFE (Fast Field Echo) (TR/TE: 83/4.6) and T2-weigthed B-FFE M2D (Balanced Fast Field Echo Multiple 2D Dimensional) (TR/TE: 3.2/1.6). Two experienced pediatric radiologists reviewed each chest radiograph and MRI for the presence of consolidation, necrosis/abscess, bronchiectasis, and pleural effusion. Chest radiograph and MRI findings were compared with Kappa statistics.

RESULTS

All consolidation, lung necrosis/abscess, bronchiectasis, and pleural effusion detected with chest radiographs were also detected with MRI. There was statistically substantial agreement between chest radiographs and MRI in detecting consolidation (k = 0.78) and bronchiectasis (k = 0.72) in children with pneumonia. The agreement between chest radiographs and MRI was moderate for detecting necrosis/abscess (k = 0.49) and fair for detecting pleural effusion (k = 0.30).

CONCLUSION

MRI with fast imaging sequences is comparable to chest radiographs for evaluating underlying pulmonary consolidation, bronchiectasis, necrosis/abscess, and pleural effusion often associated with pneumonia in children.

New noninvasive methods to diagnose vesicoureteral reflux

PURPOSE OF REVIEW

The undesirable nature of bladder imaging in children for vesicoureteral reflux detection makes the search for noninvasive bladder imaging methods and devices an urgent concern.

RECENT FINDINGS

Ultrasound imaging of the bladder aided by contrast agents can be performed without ionizing radiation. However, urethral catheterization and contrast instillation is still necessary. The accuracy and reliability are still significant problems with this method. A new method of 'hiding' gadolinium in lysosomes followed by external energy application to rupture the lysosomes releasing the gadolinium for MRI holds future hope, but this research is in its infancy. A novel method to apply external microwave energy to warm the bladder urine with microwave kidney temperature monitoring is being developed. Temperature changes noted in the kidney after bladder warming would indicate vesicoureteral reflux. Further studies are ongoing.

SUMMARY

Ultrasonography imaging of the bladder to find vesicoureteral reflux has yet to be refined enough to be accurate and reliable for clinical use. MRI studies are in their infancy but may hold future benefit. Noninvasive bladder heating and kidney temperature monitoring is showing promise in animal studies to be a completely noninvasive reflux detection device.

Paediatric CT imaging trends in Australia

INTRODUCTION

The use of CT has rapidly increased since its introduction. Although an important medical tool for diagnosis and treatment, CT is recognised as being among the highest contributors to population radiation exposure. As the risks associated with exposure are higher for children than for adults, this study assessed the impact of paediatric CT in Australia by analysing imaging trends.

METHODS

CT imaging trends were derived from Medicare data. Comparable data from a dedicated paediatric hospital (Royal Children's Hospital Melbourne (RCH)) were analysed to determine the validity of utilising Medicare statistics in the younger age groups. The resulting trends reflect the situation for paediatric CT imaging in Australia.

RESULTS

In 2009, 2.1 million CT services were billed to Medicare in Australia for children and adults. The average annual growth in the number of CT services provided since 1994 was 8.5%, compared with population growth of 1.4%. Comparison of RCH and Medicare data revealed that only one third of paediatric CT imaging is captured by Medicare. Combining the data sets showed that over the last 20 years, there has been an average annual increase of 5.1% in the CT imaging rate for 0 to 18-year-olds. However, in recent years, growth in the imaging rate for 11 to 18-year-olds has slowed, while for 5 to 10-year-olds the imaging rate has declined.

CONCLUSIONS

The significant growth in CT services is attributable to increased demand from the adult demographic. Conversely, increases in the imaging rate for paediatric patients have slowed overall. In fact, for some age groups the rate has fallen.

The influence of body mass index on the accuracy of ultrasound and computed tomography in diagnosing appendicitis in children

BACKGROUND

Appendicitis is a common pediatric surgical diagnosis that is often guided by radiographic imaging such as ultrasound (US) or computed tomography (CT). Whereas US is preferred because it avoids radiation, data suggest it is less sensitive than CT in diagnosing appendicitis. Body habitus, characterized by body mass index (BMI), may affect the diagnostic value of advanced radiological imaging in children with abdominal pain.

OBJECTIVE

The aim of the study was to determine the relationship between BMI and accuracy of US and CT scan for suspected appendicitis.

METHODS

We conducted a prospective, observational study of children with suspected appendicitis who presented to the emergency department and underwent radiographic evaluation from June 2007 to July 2008. Patient height and weight were obtained to calculate BMI and correlating z score, zBMI. Patients were grouped into standardized categories: underweight/normal weight, overweight, and obese based on zBMI. Emergency physicians ordered imaging as guided by standard clinical management. Pediatric attending radiologists evaluated all imaging studies; final radiology reports were reviewed and coded by 2 independent reviewers. Appendicitis was defined by pathology. Statistical analysis was performed to evaluate test performance of US and CT in diagnosing appendicitis as related to BMI.

RESULTS

Over the study period, 176 patients with suspected appendicitis underwent US and/or CT. Mean age was 11.8 ± 4.2 years; 42% were male. zBMI ranged from -2.78 to 2.75 (mean, 0.59); 70 children (40%) were overweight or obese; 73 (42%) had appendicitis. Ultrasound was performed on 147 (84%), and CT on 128 children (73%); 99 children (56%) had both studies. The overall sensitivity for US in diagnosing appendicitis was 38% (95% confidence interval [CI], 26%-52%) with a specificity of 97% (95% CI, 90%-99%). In the underweight/normal weight group, the sensitivity of US was 45% (95% CI, 27%-64%); in the overweight group, 35% (95% CI, 15%-61%), and in the obese group, 22% (95% CI, 4%-60%). The sensitivity and specificity of CT were 96% (95% CI, 86%-99%) and 97% (95% CI, 90%-100%) and did not vary by zBMI class.

CONCLUSIONS

The sensitivity and specificity of CT for appendicitis are excellent regardless of BMI. Despite a trend of decreasing sensitivity with increasing BMI when using US, no statistically significant difference was found, likely because of type II error.

[Evidence-based radiology for diagnostic imaging: what it is and how to practice it]

Evidence-based radiology is defined as the decision that results from integrating clinical information to select the most appropriate imaging test on the basis of the best available evidence, the physician's experience, and the patient's expectations. The practice of evidence-based radiology consists of five steps: formulating the question, performing an efficient search of the literature, critically evaluating the literature, applying the results of the search and evaluation while taking into account our experience and the patient's values, and evaluating the results obtained within our own practice. In diagnostic imaging, the number of resources available for evidence-based radiology is increasing: apart from books, articles, and web pages on this subject, evidence-based radiology is receiving more attention at diagnostic imaging conferences. The principles of evidence-based radiology will help promote the appropriate use of resources, greatly benefiting patients (decreasing the use of examinations that use ionizing radiation), professionals (less overload), and managers (more efficient use of resources).

A review of patient dose and optimisation methods in adult and paediatric CT scanning

An increasing number of publications and international reports on computed tomography (CT) have addressed important issues on optimised imaging practice and patient dose. This is partially due to recent technological developments as well as to the striking rise in the number of CT scans being requested. CT imaging has extended its role to newer applications, such as cardiac CT, CT colonography, angiography and urology. The proportion of paediatric patients undergoing CT scans has also increased. The published scientific literature was reviewed to collect information regarding effective dose levels during the most common CT examinations in adults and paediatrics. Large dose variations were observed (up to 32-fold) with some individual sites exceeding the recommended dose reference levels, indicating a large potential to reduce dose. Current estimates on radiation-related cancer risks are alarming. CT doses account for about 70% of collective dose in the UK and are amongst the highest in diagnostic radiology, however the majority of physicians underestimate the risk, demonstrating a decreased level of awareness. Exposure parameters are not always adjusted appropriately to the clinical question or to patient size, especially for children. Dose reduction techniques, such as tube-current modulation, low-tube voltage protocols, prospective echocardiography-triggered coronary angiography and iterative reconstruction algorithms can substantially decrease doses. An overview of optimisation studies is provided. The justification principle is discussed along with tools that assist clinicians in the decision-making process. There is the potential to eliminate clinically non-indicated CT scans by replacing them with alternative examinations especially for children or patients receiving multiple CT scans.

Direct chest area measurement: A potential anthropometric replacement for BMI to inform cardiac CT dose parameters?

BACKGROUND

Significant dose reductions for coronary CT angiography (CTA) can be achieved with reduced tube potential (kV); however, the potential effect on image quality is unknown.

OBJECTIVE

We sought to evaluate anthropometric measures (chest area, chest circumference, and chest attenuation) as potentially better predictors of the appropriate tube potential versus body mass index (BMI).

METHODS

Consecutive patients (n = 183) who underwent routine coronary CTA (with standard department protocols, whereby tube potential was selected according to BMI) between April 2010 and October 2010 were included. All anthropometric measures were obtained by tracing a region of interest encompassing an entire axial full field-of-view image at the mid left atrial level. Linear regression was used to stratify patients into 4 chest area classes (very small to large). Patients were also stratified by standard BMI classes (underweight to obese). Qualitative and quantitative image quality parameters were compared between concordant and discordant chest area and BMI classes.

RESULTS

A strong correlation was observed between patients' BMI and chest area (r = 0.84; P < 0.001) and between BMI and chest circumference (r = 0.82, P < 0.001). Concordance between chest area class and BMI class was found in 61%, whereas 17.6% of patients were "potentially underdosed" (chest area class > BMI class) and 21.4% were "potentially overdosed" (chest area class < BMI class). Signal and contrast of the proximal coronaries and left ventricle were significantly different between the groups.

CONCLUSION

Patients' chest area and BMI classes were frequently discordant, potentially leading to overdosing or underdosing when using BMI to select tube potential.

Deformational plagiocephaly, brachycephaly, and scaphocephaly. Part I: terminology, diagnosis, and etiopathogenesis

Cranial deformation is the most common cause of abnormal head shape. Intentional and unintentional alterations of cranial form are associated with the application of external pressure to the growing infant head, and such changes have been recorded throughout man's history. Recent changes in Western sleeping practices, instituted to reduce the incidence of sudden infant death syndrome, have led to a dramatic rise in the incidence of cranial deformation and renewed interest in this subject. This 2-part review presents a pragmatic clinical approach to this topic including a critical review of the literature as it applies to each aspect of this common diagnosis: historical perspective, terminology, differential diagnosis, etiopathogenesis and predisposing factors, and prevention and treatment.

Surgeon-performed ultrasound as a diagnostic tool in appendicitis

PURPOSE

Diagnosing appendicitis may require adjunct studies such as computed tomography or ultrasound (US). Combining a clinical examination with surgeon-performed US (SPUS) may increase diagnostic accuracy and decrease radiation exposure and costs.

METHODS

A prospective study was conducted including children with a potential diagnosis of appendicitis. A surgery resident performed a clinical examination and US to make a diagnosis. Final diagnosis of appendicitis was confirmed by operative findings and pathology. Results were compared with radiology department US (RDUS) and a large randomized trial. Analysis was performed using Fisher exact test.

RESULTS

Fifty-four patients were evaluated and underwent SPUS. Twenty-nine patients (54%) had appendicitis. Overall accuracy was 89%, with accuracy increasing from 85% to 93% between the 2 halves of the study. Radiology department US was performed on 21 patients before surgical evaluation, yielding an accuracy of 81%. Surgeon-performed US on those 21 patients yielded an accuracy of 90%. No statistical differences were found between any groups (P > .05).

CONCLUSION

Accuracy of SPUS was similar to RDUS and that of a large prospective randomized trial performed by radiologists. Furthermore, when the same clinician performs the clinical examination and US, a high level of accuracy can be achieved. With this degree of accuracy, SPUS may be used as a primary diagnostic tool and computed tomography reserved for challenging cases, limiting costs, and radiation exposure.

Measurement of cerebrovascular reactivity in pediatric patients with cerebral vasculopathy using blood oxygen level-dependent MRI

BACKGROUND AND PURPOSE

Cerebrovascular reactivity (CVR) is an indicator of cerebral hemodynamics. In adults with cerebrovascular disease, impaired CVR has been shown to be associated with an increased risk of stroke. In children, however, CVR studies are not common. This may be due to the difficulties and risks associated with current CVR study methodologies. We have previously described the application of precise control of end-tidal carbon dioxide partial pressure for CVR studies in adults. Our aim is to report initial observations of CVR studies that were performed as part of a larger observational study regarding investigations in pediatric patients with cerebral vascular disease.

METHODS

Thirteen patients between the ages of 10 and 16 years (10 with a diagnosis of Moyamoya vasculopathy and 3 with confirmed, or suspected, intracranial vascular stenosis) underwent angiography, MRI, and functional blood oxygen level-dependent MRI mapping of CVR to hypercapnia. The results of the CVR study were then related to both the structural imaging and clinical status.

RESULTS

Sixteen blood oxygen level-dependent MRI CVR studies were performed successfully in 13 consecutive patients. Twelve of the 13 patients with angiographic abnormalities also had CVR deficits in the corresponding downstream vascular territories. CVR deficits were also seen in 8 of 9 symptomatic patients and 2 of the asymptomatic patients. Notably, in patients with abnormalities on angiography, the reductions in CVR extended beyond the ischemic lesions identified with MR structural imaging into normal-appearing brain parenchyma.

CONCLUSIONS

This is the first case series reporting blood oxygen level-dependent MRI CVR in children with cerebrovascular disease. CVR studies performed so far provide information regarding hemodynamic compromise, which complements traditional clinical assessment and structural imaging.

Rising use of CT in child visits to the emergency department in the United States, 1995-2008

PURPOSE

To describe nationwide trends and factors associated with the use of computed tomography (CT) in children visiting emergency departments (EDs) in the United States between 1995 and 2008.

MATERIALS AND METHODS

This study was exempt from institutional review board oversight. Data from the 1995-2008 National Hospital Ambulatory Medical Care Survey were used to evaluate the number and percentage of visits associated with CT for patients younger than 18 years. A mean of 7375 visits were sampled each year. Data were subcategorized according to multiple patient and hospital characteristics. The Rao-Scott χ(2) test was performed to determine whether CT use was similar across subpopulations.

RESULTS

From 1995 to 2008, the number of pediatric ED visits that included CT examination increased from 0.33 to 1.65 million, a fivefold increase, with a compound annual growth rate of 13.2%. The percentage of visits associated with CT increased from 1.2% to 5.9%, a 4.8-fold increase, with a compound annual growth rate of 12.8%. The number of visits associated with CT at pediatric-focused and non-pediatric-focused EDs increased from 14,895 and 316,133, respectively, in 1995 to 212,716 and 1,438,413, respectively, in 2008. By the end of the study period, top chief complaints among those undergoing CT included head injury, abdominal pain, and headache.

CONCLUSION

Use of CT in children who visit the ED has increased substantially and occurs primarily at non-pediatric-focused facilities. This underscores the need for special attention to this vulnerable population to ensure that imaging is appropriately ordered, performed, and interpreted.

The predicted increased cancer risk associated with a single computed tomography examination for calculus detection in pediatric patients compared with the natural cancer incidence

OBJECTIVES

The objective of the study was to estimate the increased lifetime cancer risk associated with a single computed tomography (CT) examination for calculus detection in pediatric patients and compare it with the lifetime natural cancer risk.

METHODS

We used the program CT-Expo to calculate the radiation doses to various abdominal and pelvic organs for age-appropriate pediatric renal stone CT examination protocols used at our institution. Using the Biological Effects of Ionizing Radiation (BEIR) VII report, we estimated the lifelong cancer risk for these organs and compared it with the natural cancer risk for the same organs as predicted by the Surveillance, Epidemiology and End Results data from the National Cancer Institute.

RESULTS

For children 10 years or younger at the time of the examination, about 3 radiation-induced cancers are predicted for every 1000 naturally occurring cancers, and for children 15 years old, about 2 radiation-induced cancers are predicted for every 1000 naturally occurring cancers. The radiation dose from this examination is approximately equivalent to 1 to 2 years of background radiation.

CONCLUSIONS

The ratio of the risk for any abdominal and pelvic cancer due to a single CT examination for calculus detection to the risk of a naturally occurring cancer over the lifetime of a child is estimated to be 2/1000 to 3/1000. With this information, the emergency department pediatrician can more effectively counsel parents about the risk-benefit aspects of the CT examination for renal calculus disease in their children.

Diagnostic radiation exposure in pediatric trauma patients

BACKGROUND

The amount of imaging studies performed for disease diagnosis has been rapidly increasing. We examined the amount of radiation exposure that pediatric trauma patients receive because they are an at-risk population. Our hypothesis was that pediatric trauma patients are exposed to high levels of radiation during a single hospital visit.

METHODS

Retrospective review of children who presented to Johns Hopkins Pediatric Trauma Center from July 1, 2004, to June 30, 2005. Radiographic studies were recorded for each patient and doses were calculated to give a total effective dose of radiation. All radiographic studies that each child received during evaluation, including any associated hospital admission, were included.

RESULTS

A total of 945 children were evaluated during the study year. A total of 719 children were included in the analysis. Mean age was 7.8 (±4.6) years. Four thousand six hundred three radiographic studies were performed; 1,457 were computed tomography (CT) studies (31.7%). Average radiation dose was 12.8 (±12) mSv. We found that while CT accounted for only 31.7% of the radiologic studies performed, it accounted for 91% of the total radiation dose. Mean dose for admitted children was 17.9 (±13.8) mSv. Mean dose for discharged children was 8.4 (±7.8) mSv (p<0.0001). Burn injuries had the lowest radiation dose [1.2 (±2.6) mSv], whereas motor vehicle collision victims had the highest dose [18.8 (±14.7) mSv].

CONCLUSION

When the use of radiologic imaging is considered essential, cumulative radiation exposure can be high. In young children with relatively long life spans, the benefit of each imaging study and the cumulative radiation dose should be weighed against the long-term risks of increased exposure.

Evaluation of an integrated orbital tissue expander in congenital anophthalmos: report of preliminary clinical experience

PURPOSE

To evaluate the effectiveness of an orbital tissue expander designed to stimulate orbital bone growth in an anophthalmic socket.

DESIGN

Retrospective, noncomparative, interventional case series.

METHODS

SETTINGS

Institutional.

STUDY POPULATION

Nine consecutive patients with unilateral congenital anophthalmos.

INTERVENTION

The orbital tissue expander is made of an inflatable silicone globe sliding on a titanium T-plate secured to the lateral orbital rim with screws. The globe is inflated by a transconjunctival injection of normal saline through a 30-gauge needle to a final volume of approximately 5 cm(3). Computed tomography scans were used to determine the orbital volume. The data studied were: demographics, prior orbital expansion procedures, secondary interventions, orbital symmetry, and implant-related complications.

MAIN OUTCOME MEASURES

The primary outcome measure was the orbital volume change, and the secondary outcome measures were changes in forehead, brow, and zygomatic eminence contour and adverse events.

RESULTS

The average patient age at implantation was 41.89 ± 39.42 months (range, 9 to 108 months). The initial average volume of inflation was 3.00 ± 0.87 cm(3) (range, 2.0 to 4.0 cm(3)), and the average final volume of 4.33 ± 0.50 cm(3) (range, 4.0 to 5.0 cm(3)) was achieved. The duration of expansion was 18.89 ± 8.80 months (range, 4 to 26 months). All patients demonstrated an average increase in the orbital tissue expander implanted orbital volume of 5.112 ± 2.173 cm(3) (range, 2.81 to 10.38 cm(3)). The average difference between the volume of the implanted and the initial contralateral orbit was 5.68 ± 2.34 cm(3), which decreased to 2.53 ± 1.80 cm(3) at the final measurement (P < .001, paired t test). All implants remained inflated except for 2 iatrogenic punctures at the second inflation and 1 that was the result of implant failure. All were replaced.

CONCLUSIONS

The integrated orbital tissue expander is safe and effective in stimulating anophthalmic socket bone growth.