Tracheal Mirror Image Artifact in Patients With Normal and Pathologic Tracheas.

Ultrasonography is gaining popularity as a diagnostic imaging modality for airway pathology. Tracheal ultrasound (US) has several nuances that are important for clinicians, including imaging artifacts, which can be mistaken for pathology. Tracheal mirror image artifacts (TMIAs) occur when the US beam is reflected back to the transducer in a nonliner direction or with multiple timesteps. It has previously been believed that the convexity of the tracheal cartilage prevents mirror image artifacts, but in reality, the air column acts as an acoustic mirror and causes TMIA. We describe a cohort of patients with both normal and pathologic tracheas, all of whom have TMIA on the tracheal US. These artifacts are important to recognize, especially as the airway US becomes more commonplace.

Palpable pediatric chest wall masses.

Pediatric chest wall lesions are varied in etiology ranging from normal and benign to aggressive and malignant. When palpable, these lesions can alarm parents and clinicians alike. However, most palpable pediatric chest lesions are benign. Familiarity with the various entities, their incidences, and how to evaluate them with imaging is important for clinicians and radiologists. Here we review the most relevant palpable pediatric chest entities, their expected appearance and the specific clinical issues to aid in diagnosis and appropriate treatment.

Accuracy and Reliability of 4D-CT and Flexible Laryngoscopy in Upper Airway Evaluation in Robin Sequence.

OBJECTIVES: To evaluate the performance of 4-dimensional computed tomography (4D-CT) in assessing upper airway obstruction (UAO) in patients with Robin sequence (RS) and compare the accuracy and reliability of 4D-CT and flexible fiber-optic laryngoscopy (FFL). STUDY DESIGN: Prospective survey of retrospective clinical data. SETTING: Single, tertiary care pediatric hospital. METHODS: At initial and 30-day time points, a multidisciplinary group of 11 clinicians who treat RS rated UAO severity in 32 sets of 4D-CT visualizations and FFL videos (dynamic modalities) and static CT images. Raters assessed UAO at the velopharynx and oropharynx (1 = none to 5 = complete) and noted confidence levels of each rating. Intraclass correlation and Krippendorff alpha were used to assess intra- and interrater reliability, respectively. Accuracy was assessed by comparing clinician ratings with quantitative percentage constriction (QPC) ratings, calculated based on 4D-CT airway cross-sectional area. Results were compared using Wilcoxon rank-sum and signed-rank tests. RESULTS: There was similar intrarater agreement (moderate to substantial) with 4D-CT and FFL, and both demonstrated fair interrater agreement. Both modalities underestimated UAO severity, although 4D-CT ratings were significantly more accurate, as determined by QPC similarity, than FFL (-1.06 and -1.46 vs QPC ratings, P = .004). Overall confidence levels were similar for 4D-CT and FFL, but other specialists were significantly less confident in FFL ratings than were otolaryngologists (2.25 and 3.92, P < .0001). CONCLUSION: Although 4D-CT may be more accurate in assessing the degree of UAO in patients with RS, 4D-CT and FFL assessments demonstrate similar reliability. Additionally, 4D-CT may be interpreted with greater confidence by nonotolaryngologists who care for these patients.

4D Computed Tomography for Dynamic Upper Airway Evaluation in Robin Sequence.

Thorough assessment of dynamic upper airway obstruction (UAO) in Robin sequence (RS) is critical, but traditional evaluation modalities have significant limitations. Four-dimensional computed tomography (4D-CT) is promising in that it enables objective and quantitative evaluation throughout all phases of respiration. However, there exist few protocols or analysis tools to assist in obtaining and interpreting the vast amounts of obtained data. A protocol and set of data analysis tools were developed to enable quantification and visualization of dynamic 4D-CT data. This methodology was applied to a sample case at 2 time points. In the patient with RS, overall increases in normalized airway caliber were observed from 5 weeks to 1 year. There was, however, continued dynamic obstruction at all airway levels, though objective measures of UAO did improve at the nasopharynx and oropharynx. Use of 4D-CT and novel analyses provide additional quantitative information to evaluate UAO in patients with RS.

Multiple Abusive Fractures in an Infant With a Concurrent Parathyroid Hormone-Related Peptide-Secreting Renal Tumor: Abusive Fractures Accompanying a Parathyroid Hormone-Related Peptide-Secreting Tumor.

BACKGROUND: When evaluating an infant with unexplained fractures for child abuse, it is important to evaluate for possible causes of underlying bone fragility. CASE: A 7-month-old infant was found to have a parathyroid hormone (PTH)-related peptide-secreting mesoblastic nephroma. In spite of having an elevated serum calcium, depressed serum phosphate, and high levels of PTH-related peptide, he had no demineralization or other hyper parathyroid-related bone changes. Instead, he had multiple classic metaphyseal lesions, fractures of differing ages including a proximal clavicle fracture, and current and past bruising. No fractures typical of bone insufficiency were present. These findings are highly indicative of abuse in addition to his hormone-secreting tumor. CONCLUSIONS: In spite of this child's abuse findings, endogenous or tumor-related hyper PTH should be in the differential of underlying bone fragility. Children with disorders that could cause injury susceptibility can also be abused.

The Many Faces of Pediatric Chronic Recurrent Multifocal Osteomyelitis (CRMO): A Practical Location- and Case-Based Approach to Differentiate CRMO From Its Mimics.

Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease of childhood and adolescence characterized by episodic bone pain. Diagnosis relies heavily on whole-body MRI and is made by excluding a wide variety of other disorders with overlapping imaging features, depending on location, marrow distribution, and the presence or absence of multifocality. We present an overview of the clinical and imaging features of CRMO and, through various clinical scenarios, provide tips for tailoring the differential diagnosis based on location and distribution of encountered abnormalities. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 3.

Tracheal cartilaginous sleeve diagnosed on ultrasound in a child with Pfeiffer syndrome.

The tracheal cartilaginous sleeve (TCS) is a rare, difficult to diagnose airway malformation in which segmented tracheal rings are replaced by a solid sheath of cartilage. TCS is a significant cause of morbidity and mortality in patients with syndromic craniosynostosis, and early diagnosis is essential. We report a case in which ultrasound (US) was used to diagnose TCS in a patient with Pfeiffer syndrome. This is the first case demonstrating the use of US as the initial tool to diagnose TCS. The case supports ongoing research investigating the use of US as a screening and diagnostic imaging modality for TCS.

Dual-Energy CT of Pediatric Abdominal Oncology Imaging: Private Tour of New Applications of CT Technology.

OBJECTIVE. Dual-energy CT is gaining increasing recognition as a valuable diagnostic tool for assessing abdominal neoplasms. Nevertheless, much of the literature has focused on its use in adults. This review article illustrates specific tools available with dual-energy CT in the evaluation of pediatric abdominal neoplasms. Additionally, common imaging artifacts and pitfalls in dual-energy CT of the pediatric abdomen are outlined. CONCLUSION. Dual-energy CT can augment diagnostic yield in the imaging evaluation of pediatric abdominal neoplasms.

Ovarian torsion: developing a machine-learned algorithm for diagnosis.

BACKGROUND: Ovarian torsion is a common concern in girls presenting to emergency care with pelvic or abdominal pain. The diagnosis is challenging to make accurately and quickly, relying on a combination of physical exam, history and radiologic evaluation. Failure to establish the diagnosis in a timely fashion can result in irreversible ovarian ischemia with implications for future fertility. Ultrasound is the mainstay of evaluation for ovarian torsion in the pediatric population. However, even with a high index of suspicion, imaging features are not pathognomonic. OBJECTIVE: We sought to develop an algorithm to aid radiologists in diagnosing ovarian torsion using machine learning from sonographic features and to evaluate the frequency of each sonographic element. MATERIALS AND METHODS: All pediatric patients treated for ovarian torsion at a quaternary pediatric hospital over an 11-year period were identified by both an internal radiology database and hospital-based International Statistical Classification of Diseases and Related Health Problems (ICD) code review. Inclusion criteria were surgical confirmation of ovarian torsion and available imaging. Patients were excluded if the diagnosis could not be confirmed, no imaging was available for review, the ovary was not identified by imaging, or torsion involved other adnexal structures but spared the ovary. Data collection included: patient age; laterality of torsion; bilateral ovarian volumes; torsed ovarian position, i.e. whether medialized with respect to the mid-uterine line; presence or absence of Doppler signal within the torsed ovary; visualization of peripheral follicles; and presence of a mass or cyst, and free peritoneal fluid. Subsequently, we evaluated a non-torsed control cohort from April 2015 to May 2016. This cohort consisted of sequential girls and young adults presenting to the emergency department with abdominopelvic symptoms concerning for ovarian torsion but who were ultimately diagnosed otherwise. These features were then fed into supervised machine learning systems to identify and develop viable decision algorithms. We divided data into training and validation sets and assessed algorithm performance using sub-sets of the validation set. RESULTS: We identified 119 torsion-confirmed cases and 331 torsion-absent cases. Of the torsion-confirmed cases, significant imaging differences were evident for girls younger than 1 year; these girls were then excluded from analysis, and 99 pediatric patients older than 1 year were included in our study. Among these 99, all variables demonstrated statistically significant differences between the torsion-confirmed and torsion-absent groups with P-values <0.005. Using any single variable to identify torsion provided only modest detection performance, with areas under the curve (AUC) for medialization, peripheral follicles, and absence of Doppler flow of 0.76±0.16, 0.66±0.14 and 0.82±0.14, respectively. The best decision tree using a combination of variables yielded an AUC of 0.96±0.07 and required knowledge of the presence of intra-ovarian flow, peripheral follicles, the volume of both ovaries, and the presence of cysts or masses. CONCLUSION: Based on the largest series of pediatric ovarian torsion in the literature to date, we quantified sonographic features and used machine learning to create an algorithm to identify the presence of ovarian torsion - an algorithm that performs better than simple approaches relying on single features. Although complex combinations using multiple-interaction models provide slightly better performance, a clinically pragmatic decision tree can be employed to detect torsion, providing sensitivity levels of 95±14% and specificity of 92±2%.

Comparison of Micro-Computed Tomography and Clinical Computed Tomography Protocols for Visualization of Nasal Cartilage Before Surgical Planning for Rhinoplasty.

IMPORTANCE: There is no imaging standard to model nasal cartilage for the planning of rhinoplasty procedures. Preoperative visualization of cartilage may improve objective evaluation of nasal deformities, surgical planning, and surgical reconstruction. OBJECTIVES: To evaluate the feasibility of visualizing nasal cartilage using high resolution micro-computed tomography (CT) compared with the criterion standard of pathologic findings in a cadaveric specimen and to evaluate its accuracy compared with various clinical CT protocols. DESIGN, SETTING, AND PARTICIPANTS: Anatomic study at the University of Washington using single human cadaveric nasal specimens performed from July 10, 2017, to March 30, 2018. INTERVENTIONS: A micro-CT acquisition with 60-micron resolution was obtained of a nasal specimen. The specimen was then scanned with 5 different clinical CT protocols to span both clinical care and machine limits. The specimen was then sectioned in 5-mm axial slices for pathologic analysis. MAIN OUTCOMES AND MEASURES: Micro-CT images were registered to pathologic specimen cross-sections using a graphite fiducial system. Cartilage substructures were manually segmented and analyzed. A library of matched images across the micro-CT and various clinical CT protocols was then developed. Region of interest analysis was performed for each of the cartilage structures and their boundaries on clinical CT protocols and micro-CT, with the outcome of mean (SD) density using Hounsfield units. RESULTS: A single human cadaveric nasal specimen was used to obtain the following results. Lower lateral cartilage, upper lateral cartilage, and septal cartilage were accurately delineated on the micro-CT images compared with pathologic findings. The mean absolute deviation from pathologic findings was 0.30 mm for septal cartilage thickness, 0.98 mm for maximal upper lateral cartilage length, and 1.40 mm for maximal lower lateral cartilage length. On clinical CT protocols, only septal cartilage was well discriminated from boundary. Higher radiation dose resulted in more accurate density measurements of cartilage, but it did not ultimately improve ability to discriminate cartilage. CONCLUSIONS AND RELEVANCE: The results of this anatomic study may represent a notable step toward advancing knowledge of the capabilities and pitfalls of nasal cartilage visualization on CT. Nasal cartilage visualization was feasible on the micro-CT compared with pathologic findings. Future research may further examine the barriers to accurately visualizing upper lateral cartilage and lower lateral cartilage, a prerequisite for clinical application. LEVEL OF EVIDENCE: NA.

Simulation-Guided Tracheotomy in a Patient With Fibrodysplasia Ossificans Progressiva.

Fibrodysplasia ossificans progressiva (FOP) is a rare disorder that causes heterotopic bone formation leading to chest wall and spinal deformities. This case describes an 11-year-old female with FOP who presented in respiratory failure necessitating two emergent fiberoptic nasotracheal intubations. The patient had severe trismus, rotary flexion of the neck, and distortion of the airway. A three-dimensional printed model based off of a computed tomography reconstruction was created for an in situ simulation before the true procedure. The surgery and trach change were both uneventful. We propose that with careful preoperative planning, tracheotomy can be an appropriate option for FOP patients. Laryngoscope, 129:812-817, 2019.

Skeletal Dysplasias: Radiologic Approach with Common and Notable Entities.

Skeletal dysplasia is a heterogeneous group of abnormalities affecting growth and development of bone and cartilage characterized by disproportionate shortening of the limbs and/or spine. A systematic radiographic approach combined with pertinent clinical details can help guide specific genetic testing and treatment. We provide a discussion and examples of a few common and notable skeletal dysplasias to help familiarize general, pediatric, and musculoskeletal radiologists who do not commonly encounter children with these entities in their daily practices.

Spirometry-Assisted High Resolution Chest Computed Tomography in Children: Is it Worth the Effort?

BACKGROUND: Image quality of high resolution chest computed tomographies (HRCTs) depends on adequate breath holds at end inspiration and end expiration. We hypothesized that implementation of spirometry-assisted breath holds in children undergoing HRCTs would improve image quality over that obtained with voluntary breath holds by decreasing motion artifact and atelectasis. METHODS: This is a retrospective case-control study of HRCTs obtained at a tertiary care children's hospital before and after implementation of a spirometry-assisted CT protocol, in which children ≥8 years of age are first trained in supine slow vital capacity maneuvers and then repeat the maneuvers in the CT scanner, coached by a respiratory therapist. Spirometry-assisted CT scans (cases) were matched by age, gender and diagnosis (cystic fibrosis vs other) to CT scans obtained with voluntary breath holds in the 6 years before implementation of the spirometry assistance protocol (controls), and evaluated by 2 blinded pediatric radiologists. RESULTS: Among both cases and controls (N = 50 each), 10 carried the diagnosis of cystic fibrosis and 40 had other diagnoses. Mean age was 12.9 years (range: 7.5-20.1) among cases and 13.0 (7.1-19.7) among controls. Mean (SD) inspiratory image density among cases was -852 (37) Hounsfield units (HU) and -828 (43) among controls (p = 0.006). Mean (SD) expiratory image density was -629 (95) HU among cases and -688 (83) HU among controls (p = 0.002). Mean (SD) change in image density between inspiratory and expiratory images was +222 (85) HU among cases and +140 (76) HU among controls (p < 0.001). Motion artifact was present on inspiratory images in 5 cases and 9 controls (p = 0.39 by Fisher's exact test), and on expiratory images in 20 cases and 18 controls (p > 0.80). Atelectasis was present on inspiratory images in 8 cases and 9 controls and on expiratory images in 9 cases and 10 controls (p > 0.80). CONCLUSIONS: Spirometry-assisted CTs had a significantly greater difference in lung density between inspiratory and expiratory scans than those performed with voluntary breath holds, likely improving the ability to detect air trapping. No appreciable difference in image quality was detected for the presence of motion artifact or atelectasis.

A hairy situation: trichobezoar presenting with intussusception, and intestinal and biliary perforation in a child.

Trichobezoars are an uncommon cause of acute abdominal pain. We present a case of a 12-year-old girl with a history of a trichobezoar who presented to the emergency department with acute abdominal pain. Abdominal sonography was performed which suggested portal venous gas and showed complex peritoneal fluid. Subsequent computed tomography demonstrated both gastric and small bowel bezoars, with a jejunojejunal intussusception, and confirmed portal venous gas and complex ascites. At the time of surgery, there was evidence of intestinal and biliary perforation. Our case illustrates a constellation of complications in association with a long-standing trichobezoar.

Pediatric magnet ingestions: the dark side of the force.

BACKGROUND: Pediatric magnet ingestions are increasing. Commercial availability of rare-earth magnets poses a serious health risk. This study defines incidence, characteristics, and management of ingestions over time. METHODS: Cases were identified by searching radiology reports from June 2002 to December 2012 at a children's hospital and verified by chart and imaging review. Relative risk (RR) regressions determined changes in incidence and interventions over time. RESULTS: In all, 98% of ingestions occurred since 2006; 57% involved multiple magnets. Median age was 8 years (range 0 to 18); 0% of single and 56% of multiple ingestions required intervention. Compared with 2007 to 2009, ingestions increased from 2010 to 2012 (RR = 1.9, 95% confidence interval 1.2 to 3.0). Intervention proportion was unchanged (RR = .94, 95% confidence interval .4 to 2.2). Small spherical magnets comprised 26.8% of ingestions since 2010; 86% involved multiple magnets and 47% required intervention. CONCLUSIONS: Pediatric magnet ingestions and interventions have increased. Multiple ingestions prompt more imaging and surgical interventions. Magnet safety standards are needed to decrease risk to children.

Upper aerodigestive magnetic foreign bodies in children.

OBJECTIVES/HYPOTHESIS: Small, powerful magnets are increasingly available in toys and other products, and are responsible for increasing numbers of foreign body injuries in children. Small, spherical, neodymium magnets available since 2008 are of particular concern. We aimed to identify all cases of upper aerodigestive foreign bodies at our institution over 15.5 years of study. STUDY DESIGN: Case series including all patients treated at an urban, tertiary care children's hospital who had upper aerodigestive magnetic foreign bodies, from January 1, 1998 through April 30, 2013. METHODS: We manually reviewed 7,049 patient records abstracted from billing data to identify all patients 0 to 20 years of age who had upper aerodigestive magnetic foreign bodies. RESULTS: We identified four cases of upper aerodigestive magnetic foreign bodies, one involving the hypopharynx, and three involving the upper esophagus. Three occurred in 2010 or later. Two cases involve the ingestion of multiple, spherical, neodymium magnets recently marketed as desktop toys. In both of these cases, there was a rapid development of mucosal injury at the site of attraction between two magnets. CONCLUSIONS: As small, powerful magnets become more ubiquitous, pediatric magnet foreign body injuries are increasing. Although most are gastrointestinal, we identified four recent cases involving the upper aerodigestive tract. Multiple magnets lodged in the hypopharynx or esophagus can rapidly cause pressure necrosis of mucosal tissues, and merit prompt management. Education regarding magnet safety and improved magnet safety standards are needed to reduce the risk of these injuries. LEVEL OF EVIDENCE: 4.

Too attractive: the growing problem of magnet ingestions in children.

BACKGROUND: Small, powerful magnets are increasingly available in toys and other products and pose a health risk. Small spherical neodymium magnets marketed since 2008 are of particular concern. OBJECTIVE: The objective of this study was to determine the incidence, characteristics, and management of single and multiple-magnet ingestions over time. METHODS: Magnet ingestion cases at a tertiary children's hospital were identified using radiology reports from June 2002 to December 2012. Cases were verified by chart and imaging review. Relative risk regressions were used to determine changes in the incidence of ingestions and interventions over time. RESULTS: Of 56 cases of magnet ingestion, 98% occurred in 2006 or later, and 57% involved multiple magnets. Median age was 8 years (range, 0-18 years). Overall, 21% of single and 88% of multiple ingestions had 2 or more imaging series obtained, whereas no single and 56.3% of multiple ingestions required intervention (25.0% endoscopy, 18.8% surgery, 12.5% both). Magnet ingestions increased in 2010 to 2012 compared with 2007 to 2009 (relative risk, 1.9; 95% confidence interval, 1.2-3.0). Small, spherical magnets likely from magnet sets comprised 27% of ingestions, all ingested 2010 or later: 86% involved multiple magnets, 50% of which required intervention. Excluding these cases, ingestions of other magnets did not increase in 2010 to 2012 compared with 2007 to 2009 (relative risk, 0.94; 95% confidence interval, 0.6-1.4). CONCLUSIONS: The incidence of pediatric magnet ingestions and subsequent interventions has increased over time. Multiple-magnet ingestions result in high utilization of radiological imaging and surgical interventions. Recent increases parallel the increased availability of small, spherical magnet sets. Young and at-risk children should not have access to these and other small magnets. Improved regulation and magnet safety standards are needed.

Usual and unusual causes of pediatric gastric outlet obstruction.

Gastric outlet obstruction in children encompasses a spectrum of disorders that extends beyond hypertrophic pyloric stenosis. Each condition can result in the clinical syndrome of persistent nonbilious vomiting, which can progress to dehydration and electrolyte imbalances. This paper reviews the spectrum of both the common and uncommon entities that cause partial or complete gastric outlet obstruction and their imaging appearances. The correct diagnosis of those with gastric outlet obstruction can be achieved by combining clinical presentation with appropriate imaging, leading to optimal and timely patient management.