CT in children--dose protection and general considerations when planning a CT in a child

Techniques and Strategies to Minimize Radiation Exposure in Pediatric Computed Tomography (CT) Abdominal Examinations: A Review

As children are more vulnerable to radiation-induced cancers and have longer life expectancies, it is essential to implement strict radiation protection measures in pediatric imaging. This study aimed to review radiation dose-minimizing measures in pediatric abdominal computed tomography (CT) examinations. A systematic search across various databases, including Web of Science, PubMed, SpringerLink, ScienceDirect, and Google Scholar, yielded a total of 7,314 articles. The search used keywords that aligned with the objectives of the study. This study included 77 publications after applying the criteria for inclusion and exclusion. We carefully reviewed these selected articles for compliance with the inclusion criteria and excluded them if they did not meet the specified criteria. Only 12 articles fulfilled the strict criteria. An in-depth review of 12 selected articles demonstrated the radiation dose reduction techniques and strategies, which include prefiltering and post-processing algorithms, careful adjustment of exposure parameters such as tube voltage (kVp) and current (mAs), and the establishment of diagnostic reference levels (DRL). Reduction of radiation exposure in pediatric CT imaging demands multifaceted approaches. To reduce the ionizing radiation dose while still obtaining high-quality diagnostic images, healthcare practitioners should adhere to DRL, adjust exposure factors, implement prefiltration, employ AI, and use post-processing algorithms.

Radiation exposure in pediatric patients with early onset scoliosis: A longitudinal single-center study

BACKGROUND

There is no consensus regarding the acceptable level of medical radiation exposure in patients with early-onset scoliosis. This study aimed to quantify radiation exposure in these patients and investigate factors associated with high exposure.

METHODS

Patients with early-onset scoliosis who received care for their spine deformity and other comorbidities in our institution were retrospectively reviewed. Cumulative radiation exposure and total number of imaging studies were recorded. Patients with ≥30 mSv exposure were classified as high exposure and analyzed to clarify factors associated with high exposure.

RESULTS

Thirty-five patients were included for analysis. The etiology of scoliosis was idiopathic in 8 patients, congenital in 7, syndromic in 8, and neuromuscular in 12. Fifteen patients underwent 19 spinal surgeries. The types of operation performed were definitive fusion (n = 12), vertebrectomy for hemivertebra (n = 2), growing rod (n = 1), lengthening (n = 3), and revision/partial implant removal (n = 1). The mean cumulative radiation dose was 22.3 mSv (range, 2.5-94.5 mSv). Spine radiography and computed tomography combined accounted for 15.0 mSv (range, 2.4-52.5 mSv, 67.3% of the mean cumulative dose). The mean radiation dose was significantly higher in patients who underwent spinal surgery than in those who did not (31.2 mSv vs. 15.6 mSv). The high-exposure group comprised 10 patients (1 idiopathic, 1 congenital, 5 syndromic, and 3 neuromuscular scoliosis) and 8 underwent 11 spinal operations. Among 8 patients who underwent spinal surgery, the cumulative radiation dose for spine was ≥30 mSv and spine computed tomography was performed an average of 4.0 times.

CONCLUSIONS

Nearly one-third of patients with early-onset scoliosis and half of patients who underwent spinal surgery had >30 mSv radiation exposure due to multiple computed tomography. Medical radiation exposure and associated cancer risk should be considered when treating these patients.

A rare case of intervertebral disc calcification combined with ossification of the posterior longitudinal ligament in a child: a case report and literature review

BACKGROUND

Intervertebral disc calcification (IDC) combined with calcification in children has been sporadically reported, while ossification of the posterior longitudinal ligament (OPLL) in the cervical spine in pediatric patients is exceedingly rare. The aim of this study is to investigate the potential prognosis and outcomes associated with this condition.

CASE PRESENTATION

We present an unusual case involving a 10-year-old Chinese child diagnosed with calcified cervical disc herniation and ossification of the posterior longitudinal ligament. Conservative treatment measures were implemented, and at the 1-month and 6-month follow-up, the patient's pain exhibited significant improvement. Subsequent cervical MRI and CT scans revealed the complete disappearance of OPLL and substantial absorption of the calcified disc. During the three-month follow-up, CT demonstrated slight residual disc calcification, however, the patient remained asymptomatic with no discernible limitation in cervical motion.

CONCLUSIONS

We conducted a comprehensive review of several cases presenting with the same diagnosis. It is noteworthy that IDC combined with OPLL in children constitutes a rare clinical entity. Despite imaging indications of potential spinal canal occupation, the majority of such cases demonstrate complete absorption following conservative treatment, with OPLL exhibiting a faster absorption rate than calcified discs.

Bismuth Shielding in Head Computed Tomography-Still Necessary?

Introduction: Cranial CT scans are associated with radiation exposure to the eye lens, which is a particularly radiosensitive organ. Children are more vulnerable to radiation than adults. Therefore, it is essential to use the available dose reduction techniques to minimize radiation exposure. According to the European Consensus on patient contact shielding by the IRCP from 2021, shielding is not recommended in most body areas anymore. This study aims to evaluate whether bismuth shielding as well as its combination with other dose-saving technologies could still be useful. Methods: Cranial CT scans of a pediatric anthropomorphic phantom were performed on two up-to-date MDCT scanners. Eye lens dose measurements were performed using thermoluminescent dosimeters. Furthermore, the impact of BS and of the additional placement of standoff foam between the patient and BS on image quality was also assessed. Results: Bismuth shielding showed a significant lens dose reduction in both CT scanners (GE: 41.50 ± 4.04%, p < 0.001; Siemens: 29.75 ± 6.55%, p = 0.00). When combined with AEC, the dose was lowered even more (GE: 60.75 ± 3.30%, p < 0.001; Siemens: 41.25 ± 8.02%, p = 0.00). The highest eye dose reduction was achieved using BS + AEC + OBTCM (GE: 71.25 ± 2.98%, p < 0.001; Siemens: 58.75 ± 5.85%, p < 0.001). BS caused increased image noise in the orbital region, which could be mitigated by foam placement. Eye shielding had no effect on the image noise in the cranium. Conclusions: The use of BS in cranial CT can lead to a significant dose reduction, which can be further enhanced by its combination with other modern dose reduction methods. BS causes increase in image noise in the orbital region but not in the cranium. The additional use of standoff foam reduces image noise in the orbital region.

A Comprehensive Analysis of the Radiation Exposure and the Diagnostic Benefit of PanCT in Pediatric Cases with Multiple Trauma

Background and Objectives: The primary objective of this study was to obtain quantitative data, taking into account the amount of radiation exposure, about the clinical and diagnostic benefit obtained from panCT in pediatric trauma cases. Thus, we aim to create greater awareness in all physicians and primarily emergency medicine physicians regarding correct selection in terms of the patient group where this effective radiological method is to be applied, and to protect children from the adverse effects of radiation. Materials and Methods: The computed tomography (CT) images were retrieved from the hospital radiological archive system (PACS). The effective dose (Ed) was calculated using the standardized method including the tissue weighted parameters. The radiological pathologies determined as a result of CT imaging of the cases were categorized according to clinical significance in accordance with the Modified CT Colonography Reporting and Data System (C-RADS). Results: The data for a total of 268 patients were analyzed, comprising 89 (33.2%) females and 179 (66.8%) males with a mean age of 8.81 ± 5.21 years. The mean Ed was determined to be 18.14 ± 10.44 mSv. The Ed was determined to be statistically significantly higher in the 1-5 years age group than in the 15-18 years age group (p = 0.024). A statistically significant difference was determined between the age groups in terms of the pathologies determined (p = 0.028). Conclusions: In order to prevent performing unnecessary CT imaging, trauma teams in Emergency Departments (ED) should work in harmony and individual decision-making should be based on the severity of the trauma mechanism, the severity of the predicted injury, and the clinical status of the injured child.

Paediatric CT made easy

Paediatric computed tomography (CT) imaging has always been associated with challenges. Although the technical background of CT imaging is complex, it is worth considering the baseline aspects of radiation exposure to prevent unwanted excess radiation in paediatric patients. In this review, we discuss the most relevant factors influencing radiation exposure, and provide a simplified and practical approach to optimise paediatric CT.

The augmented radiologist: artificial intelligence in the practice of radiology

In medicine, particularly in radiology, there are great expectations in artificial intelligence (AI), which can "see" more than human radiologists in regard to, for example, tumor size, shape, morphology, texture and kinetics - thus enabling better care by earlier detection or more precise reports. Another point is that AI can handle large data sets in high-dimensional spaces. But it should not be forgotten that AI is only as good as the training samples available, which should ideally be numerous enough to cover all variants. On the other hand, the main feature of human intelligence is content knowledge and the ability to find near-optimal solutions. The purpose of this paper is to review the current complexity of radiology working places, to describe their advantages and shortcomings. Further, we give an AI overview of the different types and features as used so far. We also touch on the differences between AI and human intelligence in problem-solving. We present a new AI type, labeled "explainable AI," which should enable a balance/cooperation between AI and human intelligence - thus bringing both worlds in compliance with legal requirements. For support of (pediatric) radiologists, we propose the creation of an AI assistant that augments radiologists and keeps their brain free for generic tasks.

An audit of computed tomography request practices for suspected cervical spine injury post‐guideline change in a tertiary referral paediatric hospital

BACKGROUND

Paediatric neck injuries are a common presenting complaint to emergency departments (EDs). Medical imaging can assist diagnosis, however previous research suggests computed tomography (CT) scan results do not alter management in this patient group and therefore expose children to unnecessary radiation. Following an audit by the hospital Trauma Service that identified unnecessary cervical spine CTs in patients at Women's and Children's Hospital (WCH), Adelaide, the Clinical Procedure for imaging and clearance of the cervical spine in conscious patients was modified to include CT scan only at the request of the orthopaedic service. The aim of this study was to evaluate whether a change in hospital guideline resulted in a change in practice and radiation exposure.

METHODS

A retrospective review was performed for patients that presented to the WCH ED with a suspected cervical spine injury during two defined time periods pre- and post-guideline change. Mechanism of injury, imaging requested, radiation exposure and final diagnosis were compared.

RESULTS

Three hundred seventy-nine patients were included, with 164 (43.3%) post-guideline changes. Radiograph use was similar between groups, 132/215 (61.4%) versus 101/164 (61.6%) (p = 0.97). CT scan use was lower post-guideline modification 19/215 (8.8%) versus 12/164 (7.3%), however was not statistically significant (p = 0.59), with an absolute reduction of 17%.

CONCLUSION

Guideline modification at our hospital did not significantly reduce CT scan use or eliminate unnecessary CTs. Unnecessary CT scans followed lack of knowledge of and therefore compliance with guidelines. Individual hospitals should consider strategies to reduce unnecessary CTs, given the association with cancer risk in children.

Radiation use in diagnostic imaging in children: approaching the value of the pediatric radiology community

Medical imaging is foundational in the care of children, and much of the medical imaging province depends on ionizing radiation: radiography, fluoroscopy, CT and nuclear imaging. Many considerations for this imaging in children are distinct in the domains of appropriate radiation use, other factors that determine examination quality, the opportunities to engage and educate through networking, and the translation of research efforts. Given these needs, it is worth approaching the contributions and their impact by the pediatric radiology community, especially to the enhancement of this value in the care of children.

Establishment of CTPA Local Diagnostic Reference Levels with Noise Magnitude as a Quality Indicator in a Tertiary Care Hospital

This study aimed to establish the local diagnostic reference levels (LDRLs) of computed tomography pulmonary angiography (CTPA) examinations based on body size with regard to noise magnitude as a quality indicator. The records of 127 patients (55 males and 72 females) who had undergone CTPAs using a 128-slice CT scanner were retrieved. The dose information, scanning acquisition parameters, and patient demographics were recorded in standardized forms. The body size of patients was categorized into three groups based on their anteroposterior body length: P1 (14–19 cm), P2 (19–24 cm), and P3 (24–31 cm), and the radiation dose exposure was statistically compared. The image noise was determined quantitatively by measuring the standard deviation of the region of interest (ROI) at five different arteries—the ascending and descending aorta, pulmonary trunk, and the left and right main pulmonary arteries. We observed that the LDRL values were significantly different between body sizes (p < 0.05), and the median values of the CT dose index volume (CTDI_vol) for P1, P2, and P3 were 6.13, 8.3, and 21.40 mGy, respectively. It was noted that the noise reference values were 23.78, 24.26, and 23.97 HU for P1, P2, and P3, respectively, which were not significantly different from each other (p > 0.05). The CTDI_vol of 9 mGy and dose length product (DLP) of 329 mGy∙cm in this study were lower than those reported by other studies conducted elsewhere. This study successfully established the LDRLs of a local healthcare institution with the inclusion of the noise magnitude, which is comparable with other established references.

Optimization of Pediatric Body CT Angiography: What Radiologists Need to Know

OBJECTIVE. Pediatric CT angiography (CTA) presents unique challenges compared with adult CTA. Because of the ionizing radiation exposure, CTA should be used judiciously in children. The pearls offered here are observations gleaned from the authors' experience in the use of pediatric CTA. We also present some potential follies to be avoided. CONCLUSION. Understanding the underlying principles and paying meticulous attention to detail can substantially optimize dose and improve the diagnostic quality of pediatric CTA.

Measurement of cumulative radiation exposure to children and adolescents in contact with outpatients treated with low dose radioactive iodine (131I)

BACKGROUND

Radiation exposure from patients treated with radioactive iodine (¹³¹I) represents a radiation hazard to children and adolescents, representing the most vulnerable group of household contacts. Our aim was to calculate the cumulative radiation exposure (CRE) figures to children and adolescents sharing the same home with outpatients treated with low-dose ¹³¹I. The secondary aim was to study the demographic and educational factors that may significantly affect radiation exposure to them.

RESULTS

The whole number of household contacts less than 18 years was 99, out of them 49 ≤ 12 years. CRE level to children and adolescents ranged from 79 to 934 uSv. The mean, median, and 75th percentile figures were 284 ± 178 uSv, 215 uSv, and 334 uSv, respectively. The compliance of this group of contacts to radiation exposure constraint (1 mSv) was 100%. All CRE values were below this figure with 75% of them below half of this constraint. Thirteen adolescents from 12 to 18 years and 17 mothers of 23 household contacts ≤ 12 years got radiation safety instructions (RSI) directly from a radiation safety officer (RSO). This group had a significantly lower mean CRE value (184 ± 93 uSv) compared to those who got RSI from the patient or from other family members (298 ± 185 uSv) with a significant p value.

CONCLUSION

The compliance of adolescents and children to the 1-mSv radiation exposure constraint is 100%. It is advised for adolescents and mothers of children in contact with ¹³¹I-treated patients to get direct RSI from the RSO, which is the only factor associated with significantly lower radiation exposure figures.

Optimal tube voltage for abdominal enhanced CT in children: a self-controlled study

Background

The use of weight-adapted pediatric computed tomography (CT) tube voltage protocols has been suggested, but a consensus standard has not been established and clinical available studies are not sufficient.

Purpose

To determine the best tube voltage for low dose abdominal CT imaging in children.

Material and Methods

Eighty-seven cases who needed three CT exams in a 1–3-month interval between scans were enrolled (mean age = 4.69 ± 3.20 years). The three scans were performed with three different tube voltages at 80 kV, 100 kV, and 120 kV, keeping the same radiation dose and same contrast injection protocol. Patients were divided into five groups for analysis based on their body weight. The subjective image quality of the three exams were evaluated using a 4-point scale (4 being the best) for image noise and image quality. The objective evaluation in terms of CT values and standard deviation in aorta, liver, spleen, pancreas, and kidney were measured to calculate the degree of enhancement and contrast-to-noise ratio (CNR) of organs. One-way ANOVA was used to compare the subjective and objective image quality with respect to different tube voltages and different patient weights.

Result

The 80-kV tube voltage provided the highest overall enhancement and CNR for the entire patient population and the best objective image quality for the 6.1–28.0 kg subgroup.

Conclusion

Patient weight-dependent tube voltage selection maximizes image quality for abdominal enhanced CT in children. The optimal tube voltage for children with weight <28 kg is 80 kV; higher voltages should be selected for children weighing 28.1–50.0 kg.

Chest CTA in children younger than two years - a retrospective comparison of three contrast injection protocols

To obtain the highest diagnostic information with least side effects when performing thoracic CT angiography (CTA) is challenging in young children. The current study aims to compare three contrast agent (CA) injection protocols regarding image quality and CA characteristic: a standard CTA, a fixed-bolus delay protocol, and the “microbolus technique (MBT)” developed in our institution. Seventy chest CTA scans of patients (<2 years) were divided into three groups. MBT was applied in group I, the standard protocol in group II and a fixed bolus delay in group III. Objective image quality was assessed by measuring peak enhancement, image noise, signal-to-noise (SNR) and contrast-to-noise ratios (CNR). Two observers scored subjective image quality and artifacts. Significantly lower amounts of CA (mean ± SD) were used in the MBT group compared to Group II (9.0 ± 3.7 ml vs. 12.9 ± 4.5 ml). A lower, but still diagnostic (>400 HU) enhancement was registered in all major thoracic vessels in group I without significant differences regarding SNR and CNR in most regions (p < 0.05). The best scores for image quality and artifacts were reached in group I. All three chest CTA contrast injection protocols offered diagnostic vessel enhancement in young patients. MBT was associated with reduced image artifacts and less injected CA.

How to CT scan human mummies: Theoretical considerations and examples of use

OBJECTIVE

The purpose of this study was to develop and provide recommendations for computed tomography (CT) examinations of human mummies.

MATERIALS AND METHODS

Based on theoretical considerations and examples, recommendations for use are provided for scanning and image reconstruction parameters. Four examples are presented to illustrate the effect of different CT parameters on image quality.

RESULTS

The use of appropriate scanning parameters (detector collimation, pitch factor, rotation time) is known to improve image quality; technical considerations favor using lower tube voltage and higher tube current values for the purposes of scanning of human mummies. The use of appropriate image reconstruction parameters (slice thickness, increment, field of view, reconstruction filters) are the basis for individual reconstructions for the purpose of evaluation, documentation, illustration and data storage.

CONCLUSIONS

Downsizing the field of view to the region of interest as done in the clinical radiological routine represents one major tool to improve image quality.

SIGNIFICANCE

The provided recommendations should improve CT image quality in mummy studies as well as the handling of image data for reconstructions and storage.

LIMITATIONS

The recommendations for CT scanning parameters and image reconstructions were written with relatively new generation CT scanners in mind. Only a few examples of use were chosen and image quality assessment was performed subjectively and not by quantitative measurements.

Automated tube voltage selection in pediatric non-contrast chest CT

BACKGROUND

Modern CT scanners provide automatic dose adjustment systems, which are promising options for reducing radiation dose in pediatric CT scans. Their impact on patient dose, however, has not been investigated sufficiently thus far.

OBJECTIVE

To evaluate automated tube voltage selection (ATVS) in combination with automated tube current modulation (ATCM) in non-contrast pediatric chest CT, with regard to the diagnostic image quality.

MATERIALS AND METHODS

There were 160 non-contrast pediatric chest CT scans (8.7±5.4 years) analyzed retrospectively without and with ATVS. Correlations of volume CT Dose Index (CTDIvol) and effective diameter, with and without ATVS, were compared using Fisher's z-transformation. Image quality was assessed by mean signal-difference-to-noise ratios (SDNR) in the aorta and in the left main bronchus using the independent samples t-test. Two pediatric radiologists and a general radiologist rated overall subjective Image quality. Readers' agreement was assessed using weighted kappa coefficients. A p value <0.05 was considered significant.

RESULTS

CTDIvol correlation with the effective diameter was r = 0.62 without and r = 0.80 with ATVS (CI: -0.04 to -0.60; p = 0.025). Mean SDNR was 10.88 without and 10.03 with ATVS (p = 0.0089). Readers' agreement improved with ATVS (weighted kappa between pediatric radiologists from 0.1 (0.03-0.16) to 0.27 (0.09-0.45) with ATVS; between general and each pediatric radiologist from 0.1 (0.06-0.14) to 0.12 (0.05-0.20), and from 0.22 (0.11-0.34) to 0.36 (0.24-0.49)).

CONCLUSION

ATVS, combined with ATCM, results in a radiation dose reduction for pediatric non-contrast chest CT without a loss of diagnostic image quality and prevents errors in manual tube voltage setting, and thus protecting larger children against an unnecessarily high radiation exposure.

A New Method for Measuring Bell-Shaped Chest Induced by Impaired Ribcage Muscles in Spinal Muscular Atrophy Children

The involvement of the respiratory muscular pump makes SMA children prone to frequent hospitalization and morbidity, particularly in type 1. Progressive weakness affects ribcage muscles resulting in bell-shaped chest that was never quantified. The aims of the present work were: (1) to quantify the presence of bell-shaped chest in SMA infants and children and to correlate it with the action of ribcage muscles, assessed by the contribution of pulmonary ribcage to tidal volume (ΔV_{RC, p}); (2) to verify if and how the structure of the ribcage and ΔV_{RC, p} change after 1-year in SMA type 2. 91 SMA children were studied in supine position during awake spontaneous breathing: 32 with type 1 (SMA1, median age: 0.8 years), 51 with type 2 (SMA2, 3.7 years), 8 with type 3 (SMA3, 5.4 years) and 20 healthy children (HC, 5.2 years). 14 SMA2 showed negative ΔV_{RC, p} (SMA2px), index of paradoxical inspiratory inward motion. The bell-shaped chest index was defined as the ratio between the distance of the two anterior axillary lines at sternal angle and the distance between the right and left 10th costal cartilage. If this index was < < 1, it indicated bell shape, if ~1 it indicated rectangular shape, while if >> 1 an inverted triangle shape was identified. While the bell-shaped index was similar between HC (0.92) and SMA3 (0.91), it was significantly (p < 0.05) reduced in SMA2 (0.81), SMA2px (0.74) and SMA1 (0.73), being similar between the last two. There was a good correlation (Spearman's rank correlation coefficient, ρ = 0.635, p < 0.001) between ribcage geometry and ΔV_{RC, p}. After 1 year, ΔV_{RC, p} reduced while bell-shaped chest index did not change being significantly lower than HC. The shape of the ribcage was quantified and correlated with the action of ribcage muscles in SMA children. The impaired ribcage muscles function alters the ribcage structure. HC and SMA3 show an almost rectangular ribcage shape, whereas SMA2, SMA2px and SMA1 are characterized by bell-shaped chest. In SMA, therefore, a vicious cycle starts since infancy: the disease progressively affects ribcage muscles resulting in reduced expansion of lung and ribcage that ultimately alters ribcage shape. This puts the respiratory muscles at mechanical disadvantage.

Overuse of CT and MRI in paediatric emergency departments

The aim of this review is to survey CT and MRI overuse in the paediatric emergency department (ED) population. CT is one of the most important modalities employed in the ED. Not surprisingly, its high accuracy, rapid acquisition and availability have resulted in overuse. An obvious limitation of CT is ionizing radiation; in addition there are economic implications to overuse. Studies from the last two decades have shown increase in paediatric ED CT utilization in the first decade, reaching a plateau forming around 2008, followed by a decrease in the last decade. This decrease occurred in conjunction with campaigns raising awareness to the risks of radiation exposure. Although a trend of decrease in overuse have been observed, great variability has been shown across different facilities, as well as among physicians, with more pronounced overuse in non-teaching and non-children dedicated EDs. The leading types of paediatric ED CTs are head and abdominal scans. Decision rules, such as PECARN for head injury and the Alvarado score for abdominal pain, as well as using alternative imaging modalities, have been shown to reduce CT overuse in these two categories. MRI has the obvious benefit of avoiding radiation exposure, but the disadvantages of higher costs, less availability and less tolerability in younger children. Although anecdotally paediatric ED MRI usage has increased in recent years, only scarce reports have been published. In our opinion, there is need to conduct up-to-date studies covering paediatric CT and MRI overuse trends, usage variability and adherence to clinical protocols.

Ultrasound and CT of the posterior fossa in neonates

Ultrasound, CT and MRI may all be used in the evaluation of the posterior fossa in neonates depending on the clinical scenario. Ultrasonography is particularly valuable for the evaluation of the neonatal brain because of the lack of ionizing radiation and the ability to perform exams at the bedside and, importantly, advancements in ultrasound technology now allow for diagnostic-quality imaging. While CT is still the initial imaging modality of choice in most neurologic emergencies, in the neonate, ultrasound is the first line in nontraumatic emergencies. The goal of this chapter is to discuss the ultrasound technique for evaluation of the cerebellum, to describe the normal sonographic and CT appearance of posterior fossa and to provide the classical findings of the most common cerebellar abnormalities. While ultrasound is able to accurately diagnosis a majority of cerebellar abnormalities in neonates, subsequent MR imaging remains essential to confirm findings and to detect associated abnormalities.

Simplified split-bolus intravenous contrast injection technique for pediatric abdominal CT

PURPOSE

To investigate pediatric abdominal CT using a simplified split-bolus (Split group) contrast injection compared with a single bolus (Control group).

METHODS

Radiation dose, image quality and diagnostic accuracy were compared.

RESULTS

Split group demonstrated lower effective dose (2.46 vs. 2.85mSv, p=0.002) and noise levels in aorta, liver and portal vein (p<0.001). There was one false-negative case of portal vein obliteration in the Split group.

CONCLUSIONS

A simple method of split-bolus intravenous contrast injection technique can provide adequate and homogeneous enhancement in pediatric abdominal CT.

Computed tomography in children with community-acquired pneumonia

Diagnostic imaging plays a significant role in both the diagnosis and treatment of complications of pneumonia in children and chest radiography is the imaging modality of choice. Computed tomography (CT) on the other hand, is not currently a first-line imaging tool for children with suspected uncomplicated community-acquired pneumonia and is largely reserved for when complications of pneumonia are suspected or there is difficulty in differentiating pneumonia from other pathology. This review outlines the situations where CT needs to be considered in children with pneumonia, describes the imaging features of the parenchymal and pleural complications of pneumonia, discusses how CT may have a wider role in developing countries where human immunodeficiency virus (HIV) and tuberculosis are prevalent, makes note of the role of CT scanning for identifying missed foreign body aspiration and, lastly, addresses radiation concerns.

PAEDIATRIC CT EXPOSURE PRACTICE IN THE COUNTY OF RIO DE JANEIRO: THE NEED TO ESTABLISH DIAGNOSTIC REFERENCE LEVELS

A pilot study of dose indicators in paediatric computed tomography (CT) was conducted to prove the need to establish diagnostic reference levels (DRLs) for the county of Rio de Janeiro. The dose descriptors were estimated from the beam dosimetry by applying the protocols used in each examination. The total patient sample included 279 children. Regarding the comparison of the dose-length product values among the hospitals, the high-resolution chest CT scans were distinguished among the three types of examinations, due to the discrepancies of 1148 % (1-5 y age group) and 2248 % (5-10 y age group) presented in Hospital A's dose-length product values relative to Hospital D's dose-length product values. The results showed that without DRL, the dose variation can be significant between hospitals in the same county for the same age group in the same examination.

Computed Tomography and Shifts to Alternate Imaging Modalities in Hospitalized Children

BACKGROUND

Many studies have demonstrated a rise in computed tomography (CT) utilization in abstract children's hospitals. However, CT utilization may be declining, perhaps due to awareness of potential hazards of pediatric ionizing radiation, such as increased risk of malignancy. Th e objective is to assess the trend in CT utilization in hospitalized children at freestanding children's hospitals from 2004 to 2012 and we hypothesize decreases are associated with shifts to alternate imaging modalities.

METHODS

Multicenter cross-sectional study of children admitted to 33 pediatric tertiary-care hospitals participating in the Pediatric Health Information System between January 1, 2004, and December 31, 2012. The rates of CT, ultrasound, and MRI for the top 10 All-Patient Refined Diagnosis Related Groups (APR-DRGs) for which CT was performed in 2004 were determined by billing data. Rates of each imaging modality for those top 10 APR-DRGs were followed through the study period. Odds ratios of imaging were adjusted for demographics and illness severity.

RESULTS

For all included APR-DRGs except ventricular shunt procedures and nonbacterial gastroenteritis, the number of children imaged with any modality increased. CT utilization decreased for all APR-DRGs (P values , .001). For each of the APR-DRGs except seizure and infections of upper respiratory tract, the decrease in CT was associated with a significant rise in an alternative imaging modality (P values # .005).

CONCLUSIONS

For the 10 most common APR-DRGs for which children received CT in 2004,a decrease in CT utilization was found in 2012. Alternative imaging modalities for 8 of the diagnoses were used.

Pediatric Computed Tomography Dose Optimization Strategies: A Literature Review

INTRODUCTION

Computed tomography (CT) dose optimization is an important issue in radiography because CT is the largest contributor to medical radiation dose and its use is increasing. However, CT dose optimization for pediatric patients could be more challenging than their adult counterparts. The purpose of this literature review was to identify and discuss the current pediatric CT dose saving techniques. Optimized pediatric protocols were also proposed.

METHODS

A comprehensive literature search was conducted using the Medline, ProQuest Health and Medical Complete, PubMed, ScienceDirect, Scopus, Springer Link, and Web of Science databases and the keywords CT, pediatric, optimization, protocol, and radiation dose to identify articles focusing on pediatric CT dose optimization strategies published between 2004 and 2014.

RESULTS AND SUMMARY

Seventy-seven articles were identified in the literature search. Strategies for optimizing a range of scan parameters and technical considerations including tube voltage and current, iterative reconstruction, diagnostic reference levels, bowtie filters, scout view, pitch, scan collimation and time, overscanning, and overbeaming for pediatric patients with different ages and body sizes and compositions were discussed. An example of optimized pediatric protocols specific to age and body size for the 64-slice CT scanners was devised. It is expected that this example could provide medical radiation technologists, radiologists, and medical physicists with ideas to optimize their pediatric protocols.

Effect of staff training on radiation dose in pediatric CT

OBJECTIVE

To evaluate the efficacy of staff training on radiation doses applied in pediatric CT scans.

METHODS

Pediatric patient doses from five CT scanners before (1426 scans) and after staff training (2566 scans) were compared statistically. Examinations included cranial CT (CCT), thoracic, abdomen-pelvis, and trunk scans. Dose length products (DLPs) per series were extracted from CT dose reports archived in the PACS.

RESULTS

A pooled analysis of non-traumatic scans revealed a statistically significant reduction in the dose for cranial, thoracic, and abdomen/pelvis scans (p<0.01). This trend could be demonstrated also for trunk scans, however, significance could not be established due to low patient frequencies (p>0.05). The percentage of scans performed with DLPs exceeding the German DRLs was reduced from 41% to 7% (CCT), 19% to 5% (thorax-CT), from 9% to zero (abdominal-pelvis CT), and 26% to zero (trunk; DRL taken as summed DRLs for thorax plus abdomen-pelvis, reduced by 20% accounting for overlap). Comparison with Austrian DRLs - available only for CCT and thorax CT - showed a reduction from 21% to 3% (CCT), and 15 to 2% (thorax CT).

CONCLUSIONS

Staff training together with application of DRLs provide an efficient approach for optimizing radiation dose in pediatric CT practice.

Management of auto exposure control during pediatric computed tomography

Automatic exposure control (AEC) is particularly well-suited for pediatric CT scanning. However the importance of the localizer scan portion of exams that relies on AEC is frequently underestimated. This paper explains in detail several crucial aspects of the localizer and their effect on the subsequent cross-sectional (axial or helical) image acquisition. The paper also covers general suggestions regarding AEC influence on the cross-sectional images. AEC systems on CT scanners are becoming more complex; using them effectively in the setting of pediatric CT requires careful selection of scan parameters.

Pathways and barriers to developing pediatric research consortia

In many countries pediatric radiology is responsible for imaging of patients ranging from premature babies to 19-year-olds, thus meaning a weight range from less than 500 g to sometimes much more than 100 kg. Children are not small adults and many differences exist when comparing them to adults. Therefore pediatric radiologists face a 4-D problem: the three dimensions in space as well as time, which can be summarized as maturation. Due to this multidimensionality experience exchange, knowledge transfer and teamwork is mandatory. Research consortia represent a useful approach. According the author's experience in setting up and running international, inter-institutional academic networks, this article describes pathways and barriers of such cooperations, which can be divided into external (institutional), internal (departmental) and organizational and by the research fellows themselves.

The use of arthrography in pediatric orthopaedic surgery

Surgery near pediatric joints can be challenging because it is difficult to visualize vital articular structures. Assessment of underlying pathology is also challenging because the joint structures have not yet ossified. Arthrography is a useful tool that is quick and minimally invasive and allows adequate visualization of joint anatomy during surgery, which aids intraoperative decision making. In pediatric patients, arthrography is most useful for visualization of the elbow, knee, and hip joints. This tool can help the surgeon to refine the diagnosis and management of pediatric fractures and aids in surgical assessment during joint and limb reconstruction. Arthrography adds minimal time to surgery and carries a low risk of complications; it should be part of the armamentarium of any surgeon who treats pediatric orthopaedic patients.

Performance of lung ultrasonography in children with community-acquired pneumonia

Background

There are few prospective evaluations of point-of-care ultrasonography (US) for the diagnosis of pediatric community-acquired pneumonia (CAP). In particular, there are very few data concerning the efficiency of US in comparison with that of chest radiography (CR) in defining different kinds of lung alterations in the various pulmonary sections. The aim of this study was to bridge this gap in order to increase our knowledge of the performance of US in diagnosing CAP in childhood.

Methods

A total of 103 children (56 males, 54.4%; mean age ± standard deviation 5.6 ± 4.6 years) admitted to hospital with a clinical diagnosis of suspected CAP were prospectively enrolled and underwent CR (evaluated by an independent expert radiologist) and lung US (performed by a resident in paediatrics with limited experience in US). The performance of US in diagnosing CAP (i.e. its sensitivity, specificity, and positive and negative predictive values) was compared with that of CR.

Results

A total of 48 patients had radiographically confirmed CAP. The sensitivity, specificity, and positive and negative predictive values of US in comparison with CR were respectively 97.9%, 94.5%, 94.0% and 98.1%. US identified a significantly higher number of cases of pleural effusion, but the concordance of the two methods in identifying the type of CAP was poor.

Conclusion

US can be considered a useful means of diagnosing CAP in children admitted to an Emergency Department with a lower respiratory tract infection, although its usefulness in identifying the type of lung involvement requires further evaluation.