Image Gently® at 10 Years

Unlocking the potential of photon counting detector CT for paediatric imaging: a pictorial essay

Recent advancements in CT technology have introduced a revolutionary innovation to practice known as the Photon-Counting detector (PCD) CT imaging. The pivotal hardware enhancement of the PCD-CT scanner lies in its detectors, which consist of smaller pixels than standard detectors and allow direct conversion of individual X-rays to electrical signals. As a result, CT images are reconstructed at higher spatial resolution (as low as 0.2 mm) and reduced overall noise, at no expense of an increased radiation dose. These features are crucial for paediatric imaging, especially for infants and young children, where anatomical structures are notably smaller than in adults and in whom keeping dose as low as possible is especially relevant. Since January 2022, our hospital has had the opportunity to work with PCD-CT technology for paediatric imaging. This pictorial review will showcase clinical examples of PCD-CT imaging in children. The aim of this pictorial review is to outline the potential paediatric applications of PCD-CT across different anatomical regions, as well as to discuss the benefits in utilizing PCD-CT in comparison to conventional standard energy integrating detector CT.

Paediatric CBCT protocols for image-guided radiotherapy; outcome of a survey across SIOP Europe affiliated countries and literature review

BACKGROUND

Implementation of daily cone-beam CT (CBCT) into clinical practice in paediatric image-guided radiotherapy (IGRT) lags behind compared to adults. Surveys report wide variation in practice for paediatric IGRT and technical information remains unreported. In this study we report on technical settings from applied paediatric CBCT protocols and review the literature for paediatric CBCT protocols.

METHODS

From September to October 2022, a survey was conducted among 246 SIOPE-affiliated centres across 35 countries. The survey consisted of 3 parts: 1) baseline information; technical CBCT exposure settings and patient set-up procedure for 2) brain/head, and 3) abdomen. Descriptive statistics was used to summarise current practice. The literature was reviewed systematically with two reviewers obtaining consensus RESULTS: The literature search revealed 22 papers concerning paediatric CBCT protocols. Seven papers focused on dose-optimisation. Responses from 50/246 centres in 25/35 countries were collected: 44/50 treated with photons and 10/50 with protons. In total, 48 brain/head and 53 abdominal protocols were reported. 42/50 centres used kV-CBCT for brain/head and 35/50 for abdomen; daily CBCT was used for brain/head = 28/48 (58%) and abdomen = 33/53 62%. Greater consistency was seen in brain/head protocols (dose range 0.32 - 67.7 mGy) compared to abdominal (dose range 0.27 - 119.7 mGy).

CONCLUSION

Although daily CBCT is now widely used in paediatric IGRT, our survey demonstrates a wide range of technical settings, suggesting an unmet need to optimise paediatric IGRT protocols. This is in accordance with the literature. However, there are only few paediatric optimisation studies suggesting that dose reduction is possible while maintaining image quality.

Medical imaging utilization and associated radiation exposure in children with down syndrome

OBJECTIVE

To evaluate the frequency of medical imaging or estimated associated radiation exposure in children with Down syndrome.

METHODS

This retrospective cohort study included 4,348,226 children enrolled in six U.S. integrated healthcare systems from 1996-2016, 3,095 of whom were diagnosed with Down syndrome. We calculated imaging rates per 100 person years and associated red bone marrow dose (mGy). Relative rates (RR) of imaging in children with versus without Down syndrome were estimated using overdispersed Poisson regression.

RESULTS

Compared to other children, children with Down syndrome received imaging using ionizing radiation at 9.5 times (95% confidence interval[CI] = 8.2-10.9) the rate when age <1 year and 2.3 times (95% CI = 2.0-2.5) between ages 1-18 years. Imaging rates by modality in children <1 year with Down syndrome compared with other children were: computed tomography (6.6 vs. 2.0, RR = 3.1[95%CI = 1.8-5.1]), fluoroscopy (37.1 vs. 3.1, RR 11.9[95%CI 9.5-14.8]), angiography (7.6 vs. 0.2, RR = 35.8[95%CI = 20.6-62.2]), nuclear medicine (6.0 vs. 0.6, RR = 8.2[95% CI = 5.3-12.7]), radiography (419.7 vs. 36.9, RR = 11.3[95%CI = 10.0-12.9], magnetic resonance imaging(7.3 vs. 1.5, RR = 4.2[95% CI = 3.1-5.8]), and ultrasound (231.2 vs. 16.4, RR = 12.6[95% CI = 9.9-15.9]). Mean cumulative red bone marrow dose from imaging over a mean of 4.2 years was 2-fold higher in children with Down syndrome compared with other children (4.7 vs. 1.9mGy).

CONCLUSIONS

Children with Down syndrome experienced more medical imaging and higher radiation exposure than other children, especially at young ages when they are more vulnerable to radiation. Clinicians should consider incorporating strategic management decisions when imaging this high-risk population.

A Narrative Review of the Uses of Ultrasound in the Evaluation, Analgesia, and Treatment of Distal Forearm Fractures

BACKGROUND

Distal forearm fractures are a commonly encountered injury in the emergency department (ED), accounting for 500,000 to 1.5 million visits and 17% of ED fractures. The evaluation and management of these fractures frequently employs x-ray studies, conscious sedation, closed reduction, and splinting. Point-of-care ultrasound (POCUS) can offer significant benefit in the diagnosis and management of these common injuries.

OBJECTIVE OF THE REVIEW

To review the clinical utility of POCUS in the diagnosis of distal forearm fractures, as well as to demonstrate the performance of ultrasound-guided analgesia delivery and ultrasound-guided reduction technique.

DISCUSSION

The initial evaluation of forearm injuries frequently includes x-ray studies. However, multiple studies have shown ultrasound to be sensitive and specific for distal radius fractures, with the added value of detecting soft tissue injuries missed by conventional radiography. POCUS may also facilitate analgesia through the use of ultrasound-guided hematoma blocks, which removes the need for conscious sedation prior to manipulation. Finally, POCUS can be used after manipulation to assess cortical realignment of the bone fragments and spare the patient multiple reduction attempts and repeat radiographs.

CONCLUSION

Distal forearm fractures are common, and the emergency physician should be adept with the evaluation and management of these injuries. POCUS can be a reliable modality in the detection of these fractures and can be used to facilitate analgesia and augment success of reduction attempts. These techniques may decrease length of stay, improve patient pain, and decrease reduction attempts.

Impact of neck CT on the management of suspected pediatric deep neck space infection

OBJECTIVE

To identify clinical and radiographic factors that predict successful medical management in children with suspected deep neck space infection.

METHODS

Retrospective chart review of 313 immunocompetent children admitted to a tertiary care children's hospital after undergoing a CT scan for a suspected neck abscess.

RESULTS

A rim-enhancing hypodensity, suggestive of an abscess, was identified in 131/313 patients (42%). Medical management with IV antibiotics was utilized for more than 24 h in 57/131 (43%) of children with radiographic findings suggestive of a coalescent or evolving abscess. Medical management was successful in 36/57 (63%) of patients with a rim-enhancing collection. Children who underwent incision and drainage within 24 h had a larger fluid collection than those who underwent initial medical management (mean diameter 30 mm vs 20.5 mm; p < 0.0001), however, there was no difference between the size of abscesses that failed medical management compared to those successfully managed with IV antibiotics (22.9 mm vs 19.1 mm; p = 0.07). Clinical factors and white blood cell count were not predictive of response to antibiosis.

CONCLUSION

The majority of children with suspected DNSI were successfully managed with IV antibiotics alone, however, clinical and radiographic factors are not reliable predictors of successful medical management. In children who are hemodynamically stable without airway symptoms, one should consider a trial of IV antibiotics prior to requesting a CT scan.

Local diagnostic reference levels for skeletal surveys in suspected physical child abuse

INTRODUCTION

The purpose was to determine if an age based, local diagnostic reference level for paediatric skeletal surveys could be established using retrospective data.

METHODS

All children below two years of age referred for a primary skeletal survey as a result of suspected physical abuse during 2017 or 2018 (n = 45) were retrospectively included from a large Danish university hospital. The skeletal survey protocol included a total of 33 images. Dose Area Product (DAP) and acquisition parameters for all images were recorded from the Picture Archival and Communication System (PACS) and effective dose was estimated. The 75th percentile for DAP was considered as the diagnostic reference level (DRL).

RESULTS

The 75th percentile for DAP was 314 mGy∗cm², 520 mGy∗cm² and 779 mGy∗cm² for children <1 month, 1-11 months and 12 < 24 months of age respectively. However, only the age group 1-11 months had a sufficient number of children (n = 27) to establish a local DRL. Thus, for the other groups the DAP result must be interpreted with caution. Effective dose was 0.19, 0.26 and 0.18 mSv for children <1, 1-11 months and 12 < 24 months of age respectively.

CONCLUSION

For children between 1 and 11 months of age, a local diagnostic reference level of 520 mGy∗cm² was determined. This may be used as an initial benchmark for primary skeletal surveys as a result of suspected physical abuse for comparison and future discussion.

IMPLICATIONS FOR PRACTICE

While the data presented reflects the results of a single department, the suggested diagnostic reference level may be used as a benchmark for other departments when auditing skeletal survey radiation dose.

Utilization of CT imaging in minor pediatric head, thoracic, and abdominal trauma in the United States

BACKGROUND

Liberal use of CT scanning in children with blunt trauma risks unnecessary radiation exposure and cost. Recent literature questions the utility of whole-body CT in stable children without clinical evidence of significant injury, but this is often done based on injury mechanism. The purpose of this study is to quantify the utilization of CT scans of the head, chest, abdomen, and pelvis based on injury severity in these body regions and to assess the impact of American College of Surgeons (ACS) pediatric trauma center designation on CT utilization in children with minor or no injuries.

METHODS

We queried the National Trauma Databank for 2014, 2015, and 2016 to identify all patients 14 years and younger. Using Abbreviated Injury Scale (AIS) score as a proxy for injury severity, we analyzed the number of head, thoracic, and abdominal CT scans done for patients at low levels of injury severity (AIS 0-2) in each of these body regions and according to trauma center level designation (ACS I, II, III, standalone pediatric I or II, and non ACS accredited).

RESULTS

Of 257,661 children who were entered into the database for any reason, overall CT utilization was 20% for head, 5% for the chest and 9% for the abdomen and pelvis. Children with no injuries or minimal injury to the head were scanned 7% and 46% of the time, respectively, for the chest 3% and 13% and for the abdomen 6% and 30%. For all body regions and all levels of injury severity, level 1 stand-alone pediatric centers displayed significantly lower CT utilization rates than others.

CONCLUSION

CT scan rates for children with minimal or no injuries to the head, chest, abdomen and pelvis are significant. Level 1 stand-alone pediatric trauma centers are least likely to perform these studies. Widespread education and acceptance of clinical guidelines for imaging in stable patients throughout trauma systems could alleviate this disparity.

LEVEL OF EVIDENCE

Level III retrospective comparative study.

Utilization of computed tomography imaging in the pediatric emergency department

BACKGROUND

In recent years, there has been a movement toward more judicious use of computed tomography (CT) imaging in an attempt to limit exposure of pediatric patients to ionizing radiation. The Image Gently Alliance and like-minded movements began advocating for safe and high-quality pediatric imaging worldwide in the late 2000s.

OBJECTIVE

In the context of these efforts, we evaluate CT utilization rates in the pediatric emergency department at a major academic medical center.

MATERIALS AND METHODS

We tracked utilization in several categories of CT, magnetic resonance imaging (MRI) and ultrasonography (US) between July 2008 and June 2017 and compared them with utilization rates from 2000 to 2006.

RESULTS

A total of 4,955 pediatric patients underwent a total of 5,973 CT scans, 2,775 US studies and 293 MRI scans while in the pediatric emergency department during the 2008-2017 study period. We observed decreases in CT scans across all categories, ranging from a 19% decrease in abdominal CT to a 66% decrease in chest CT. Relatively greater decreases in CT scans were observed in patients younger than 3 years of age as compared to older children and adolescents. Abdominal and pelvic US increased. Brain MRI also increased over the final two years of the study.

CONCLUSION

CT utilization decreased throughout the 2008-2017 study period.

Achieving CT Regulatory Compliance: A Comprehensive and Continuous Quality Improvement Approach

Computed tomography (CT) represents one of the largest sources of radiation exposure to the public in the United States. Regulatory requirements now mandate dose tracking for all exams and investigation of dose events that exceed set dose thresholds. Radiology practices are tasked with ensuring quality control and optimizing patient CT exam doses while maintaining diagnostic efficacy. Meeting regulatory requirements necessitates the development of an effective quality program in CT. This review provides a template for accreditation compliant quality control and CT dose optimization. The following paper summarizes a large health system approach for establishing a quality program in CT and discusses successes, challenges, and future needs.