Neil D. Johnson

The 'Image Gently' campaign: increasing CT radiation dose awareness through a national education and awareness program

ALARA (As Low As Reasonably Achievable) has been a guiding principle for pediatric radiologists for decades. The Society for Pediatric Radiology (SPR) has long been a leader in promoting safety in radiology practice in children. However, the ALARA principle has taken on new meaning in the past several years as the number of CT scans in children has skyrocketed. For example, it is estimated that since the 1980s when CT was beginning its ascendancy there has been up to an 800% increase. CT scans in children provide great benefit in patient care when used appropriately. However, increased use requires a team approach to ensure that only indicated exams are performed and at the Pediatr Radiol (2008) 38:265–269 DOI 10.1007/s00247-007-0743-3

Live 3D Guidance in the Interventional Radiology Suite

OBJECTIVE The development of a C-arm cone-beam CT unit coupled with flat detectors has markedly increased anatomic visualization capabilities for interventional radiology procedures. We present technology in which fluoroscopy and 3D imaging from a cone-beam CT-flat-detector C-arm unit are combined with an integrated tracking and navigation system. A description of the technology and representative clinical cases are presented. CONCLUSION This new combination further increases interventional radiologic capabilities because it provides real-time procedural evaluation and tracking.

Pancreatic trauma in children: mechanisms of injury

BACKGROUND Pancreatic trauma occurs in up to 10% of all cases of blunt pediatric trauma. Here we attempted to identify markers of pancreatic injury in children and to assess our current diagnostic approach to pancreatic injury. METHOD We performed a retrospective chart review of all patients with a pancreatic injury admitted to a Level I pediatric trauma center between January of 1980 and September of 1994. RESULTS In all, 26 children were included. All pancreatic injuries were due to blunt trauma. Handlebar injuries were the most common mechanism of injury and resulted in a unique pattern of isolated pancreatic trauma, often complicated by the development of a pseudocyst. Computed tomographic scans, performed with intravenous and oral contrast and done in the acute setting, were 85% sensitive for diagnosing a pancreatic injury. CONCLUSIONS Double contrast computed tomographic scan is a more sensitive test than ultrasound in diagnosing pancreatic injury. The constellation of abdominal pain, an elevated serum amylase and a handlebar mechanism of injury warrants hospitalization and a double contrast abdominal computed tomographic scan.

Tarsal coalition: a blinded comparison of MRI and CT

Objective. To determine how well MRI can detect tarsal coalition compared with CT, the current imaging standard. Materials and methods. Coronal and axial CT and MRI were performed within 3 weeks of each other on 40 feet in 20 consecutive patients referred with symptoms of possible tarsal coalition. Scans were read independently in blinded fashion by different imagers. Coalitions were either complete (osseous) or incomplete (non-osseous). Results were compared with available surgical data and clinical follow-up. Results. Both modalities prospectively identified 15 coalitions (9 patients) and each missed 1 calcaneonavicular coalition. Twenty-three of the remaining 24 feet were negative for coalition on both CT and MRI. An atypical incomplete talocalcaneal coalition seen on CT was not identified prospectively on MRI. Conclusion. MRI is very good for detecting tarsal coalition and has a high rate of agreement with CT, the imaging “gold standard.” When clinical suspicion for coalition is high, CT remains a more cost-effective diagnostic modality. If other causes for ankle pain are also entertained, MRI can be performed and provide nearly equivalent diagnostic accuracy for detecting tarsal coalition.

Image GentlySM: A National Education and Communication Campaign in Radiology Using the Science of Social Marketing

Communication campaigns are an accepted method for altering societal attitudes, increasing knowledge, and achieving social and behavioral change particularly within public health and the social sciences. The Image Gently(SM) campaign is a national education and awareness campaign in radiology designed to promote the need for and opportunities to decrease radiation to children when CT scans are indicated. In this article, the relatively new science of social marketing is reviewed and the theoretical basis for an effective communication campaign in radiology is discussed. Communication strategies are considered and the type of outcomes that should be measured are reviewed. This methodology has demonstrated that simple, straightforward safety messages on radiation protection targeted to medical professionals throughout the radiology community, utilizing multiple media, can affect awareness potentially leading to change in practice.

Anatomic distribution of renal artery stenosis in children: implications for imaging

BackgroundRenal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment.ObjectiveTo identify locations of RAS lesions in these hypertensive children without comorbid conditions.Materials and methodsPatients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses.ResultsEighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery.ConclusionHypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty.

Image Gently: Providing Practical Educational Tools and Advocacy to Accelerate Radiation Protection for Children Worldwide

The Alliance for Radiation Safety in Pediatric Imaging is an organization of over 45 international professional societies and agencies with the goal of promoting radiation safety for children. The Alliance, through the Image Gently campaign, uses social marketing techniques and critical partnerships with vendors, government agencies, and not-for-profit organizations, to advocate best practices in radiation use and safety. Advocacies include improving education regarding radiation risk to patients from medical imaging for radiologists, technologists, and referring physicians; promoting standardization of dose measurements and display across vendor equipment; and improving medical literacy for parents.

Is the frontal radiograph alone sufficient to evaluate for pneumonia in children

BackgroundIn our cost- and radiation-conscious environment, the feasibility of performing only a frontal radiograph for the diagnosis of pneumonia in children needs to be reassessed.ObjectiveTo determine the diagnostic efficacy of the frontal radiograph alone in comparison to the frontal and lateral combined radiographs for the radiographic diagnosis of pneumonia in children.Materials and methodsThree radiologists retrospectively and independently reviewed the frontal radiographs alone and separately reviewed the frontal and lateral radiographs of 1,268 children referred from the emergency room for chest radiographs. A majority interpretation of at least two radiologists for the frontal views alone was compared with majority interpretation of the frontal and lateral combined views for the radiographic diagnosis of pneumonia. “Pneumonia” was defined as a focus of streaky or confluent lung opacity.ResultsFor the radiographic diagnosis of pneumonia, the sensitivity and specificity of the frontal view alone were 85% and 98%, respectively. For the confluent lobar type of pneumonia, the sensitivity and specificity increased to 100%.ConclusionWhen the frontal view alone yields a diagnosis of confluent lobar pneumonia, this is highly reliable. However, nonlobar types of infiltrates will be underdiagnosed in 15% of patients using the frontal view alone. The clinical impact of these radiographically underdiagnosed pneumonias needs to be assessed prior to implementing the practice of using only frontal radiographs for diagnosing pneumonia.

Communication in Diagnostic Radiology: Meeting the Challenges of Complexity

OBJECTIVE As patients and information flow through the imaging process, value is added step-by-step when information is acquired, interpreted, and communicated back to the referring clinician. However, radiology information systems are often plagued with communication errors and delays. This article presents theories and recommends strategies to continuously improve communication in the complex environment of modern radiology. CONCLUSION Communication theories, methods, and systems that have proven their effectiveness in other environments can serve as models for radiology.

Significant Dose Reduction for Pediatric Digital Subtraction Angiography Without Impairing Image Quality: Preclinical Study in a Piglet Model

OBJECTIVE The purpose of this study was to validate the hypothesis that image quality of digital subtraction angiography (DSA) in pediatrics is not impaired when using a low-dose acquisition protocol. MATERIALS AND METHODS Three piglets corresponding to common pediatric population sizes were used. DSA was performed in the aorta and renal, hepatic, and superior mesenteric arteries using both the commonly used reference standard and novel radiographic imaging noise reduction technologies to ensure pairwise radiation dose and image quality comparison. The air kerma per frame at the interventional reference point for each DSA acquisition was collected as a radiation dose measure, and image quality was evaluated by five interventional radiologists in a randomized blinded fashion using a 5-point scale. RESULTS The mean air kerma (± SD) at the interventional reference point with the novel x-ray imaging noise reduction technology was significantly lower (1.1 ± 0.8 mGy/frame) than with the reference technology (4.2 ± 3.0 mGy/frame, p = 0.005). However, image quality was statistically similar, with average scores of 3.2 ± 0.4 and 3.1 ± 0.5 for the novel and reference technologies, respectively (p = 0.934); interrater absolute agreement was 0.77. CONCLUSION The DSA radiation dose for pediatrics can be reduced by a factor of four with a novel x-ray imaging noise reduction technology without deterioration of image quality.