Bacterial osteomyelitis in pediatric patients: a comprehensive review.

Bacterial osteomyelitis, an inflammatory response in the bone caused by microorganisms, typically affects the metaphysis in the skeletally immature. Bacterial osteomyelitis possesses a significant diagnostic challenge in pediatric patients due to its nonspecific clinical presentation. Because the metaphysis is the primary focus of infection in skeletally immature patients, understanding the normal physiologic, maturation process of bones throughout childhood allows to understand the pathophysiology of osteomyelitis. Timely and accurate diagnosis is crucial to initiate appropriate treatment, and prevent long-term sequelae and efforts must be made to isolate the causative organism. The potential causative organism changes according to the age of the patient and underlying medical conditions. Staphylococcus Aureus is the most common isolated bacteria in pediatric pyogenic osteomyelitis whereas Kingella Kingae is the most common causative agent in children aged 6 months to 4 years. Imaging plays a pivotal role in the diagnosis, characterization, evaluation of complications, and follow up of bacterial osteomyelitis. Imaging also plays a pivotal role in the evaluation of potential neoplastic and non-neoplastic mimickers of osteomyelitis. In children, MRI is currently the gold standard imaging modality when suspecting bacterial osteomyelitis, whereas surgical intervention may be required in order to isolate the microorganism, treat complications, and exclude mimickers.

Contrast-Enhanced Ultrasound of the Chest in Children and Adolescents: A Pilot Study for Assessment of Added Diagnostic Value.

OBJECTIVES: To determine the added diagnostic value of contrast-enhanced ultrasound (CEUS) in pediatric chest abnormalities by comparing interpretation of CEUS studies and confidence level to conventional US studies. METHODS: CEUS studies in patients with a variety of clinically suspected chest abnormalities performed between 2016 and 2020 were reviewed and compared to same-day conventional US studies. Examinations were independently interpreted by 4 radiologists blinded to clinical and other imaging data. Rater confidence was classified as low, moderate, or high. Diagnostic accuracy was determined by comparing image interpretation to patient outcome as the ground truth. Interobserver agreement was also assessed. RESULTS: Sixteen patients (10 male) with 18 CEUS studies were included. Median rater agreement with ground truth was significantly higher for CEUS (100%) than conventional US (50%; P = .004). Median rater confidence was high (3.0) for CEUS, and low-moderate (1.5) for conventional US (P < .001). CEUS sensitivity (54.6-81.8%) and specificity (63.4-100.0%) were greater than conventional US (45.5-72.7% and 12.5-63.5%, respectively). CEUS false positives (0-4) and false negatives (2-5) were fewer than conventional US (4-7 and 3-6, respectively). Except for one rater pair where agreement was substantial (κ = .78, P < .01), inter-rater agreement for CEUS for all other rater pairs was nonsignificant (κ = .25-0.51, P ≥ .07). Agreement for conventional US was moderate and statistically significant for 3 rater pairs (κ = .55-0.78) and nonsignificant for the remaining 3 rater pairs (P ≥ .06). CONCLUSIONS: CEUS adds diagnostic value to the assessment of a variety of chest abnormalities. The data support further evaluation of the role of CEUS as a non-invasive, problem-solving technique in children.

Secondary Pulmonary Vein Stenosis Due to Total Anomalous Pulmonary Venous Connection Repair in Children: Extravascular MDCT Findings.

PURPOSE: To evaluate extravascular findings on thoracic MDCT angiography in secondary pulmonary vein stenosis (PVS) due to total anomalous pulmonary venous connection (TAPVC) repair in children. MATERIALS AND METHODS: All patients aged ≤18 years with a known diagnosis of secondary PVS after TAPVC repair, confirmed by echocardiography, conventional angiography, and/or surgery, who underwent thoracic MDCT angiography studies between July 2008 and April 2021 were included. Two pediatric radiologists independently examined MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung, pleura, and mediastinum. The location and distribution of each abnormality (in relation to the location of PVS) were also evaluated. Interobserver agreement between the two independent pediatric radiology reviewers was studied using kappa statistics. RESULTS: The study group consisted of 20 consecutive pediatric patients (17 males, 3 females) with secondary PVS due to TAPVC repair. Age ranged from 2 months to 8 years (mean, 16.1 months). In children with secondary PVS due to TAPVC repair, the characteristic extravascular thoracic MDCT angiography findings were ground-glass opacity (19/20; 95%), septal thickening (7/20; 35%), pleural thickening (17/20; 85%), and a poorly defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (17/20; 85%) which followed the contours of affected pulmonary veins outside the lung. There was excellent interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). CONCLUSION: Our study characterizes the extravascular thoracic MDCT angiography findings in secondary pediatric PVS due to TAPVC repair. In the lungs and pleura, ground-glass opacity, interlobular septal thickening, and pleural thickening are common findings. Importantly, the presence of a mildly heterogeneously enhancing, non-calcified mediastinal soft tissue mass in the distribution of the PVS is a novel characteristic thoracic MDCT angiography finding seen in pediatric secondary PVS due to TAPVC repair.

Extravascular MDCT Findings of Pulmonary Vein Stenosis in Children with Cardiac Septal Defect.

Purpose: To retrospectively investigate the extravascular thoracic MDCT angiography findings of pulmonary vein stenosis (PVS) in children with a cardiac septal defect. Materials and Methods: Pediatric patients (age ≤ 18 years) with cardiac septal defect and PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from April 2009 to April 2021 were included. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in: (1) lung and airway (ground-glass opacity (GGO), consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis); (2) pleura (pleural thickening, pleural effusion, and pneumothorax); and (3) mediastinum (mass and lymphadenopathy). Interobserver agreement between the two independent pediatric radiology reviewers was evaluated with kappa statistics. Results: The final study group consisted of 20 thoracic MDCT angiography studies from 20 consecutive individual pediatric patients (13 males (65%) and 7 females (35%); mean age: 7.5 months; SD: 12.7; range: 2 days to 7 months) with cardiac septal defect and PVS. The characteristic extravascular thoracic MDCT angiography findings were GGO (18/20; 90%), septal thickening (9/20; 45%), pleural thickening (16/20; 80%), and ill-defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (9/20; 45%) following the contours of PVS in the mediastinum. There was a high interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: PVS in children with a cardiac septal defect has a characteristic extravascular thoracic MDCT angiography finding. In the lungs and pleura, GGO, septal thickening, and pleural thickening are frequently seen in children with cardiac septal defect and PVS. In the mediastinum, a mildly heterogeneously enhancing, non-calcified soft tissue mass in the distribution of PVS in the mediastinum is seen in close to half of the pediatric patients with cardiac septal defect and PVS.

Thoracic Multidetector Computed Tomography Findings of Dedicator of Cytokinesis 8 Deficiency in Children.

PURPOSE: To investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of dedicator of cytokinesis 8 (DOCK8) deficiency, a rare autosomal recessive form of hyperimmunoglobulin E syndrome, in children. MATERIALS AND METHODS: All pediatric patients (age 18 y and below) with a known diagnosis of DOCK8 deficiency based on genetic testing who underwent thoracic MDCT studies from November 2004 to November 2020 were included. Two pediatric radiologists independently evaluated MDCT studies for the presence of thoracic abnormalities in the lung [ground-glass opacity (GGO), consolidation, pulmonary nodule, mass, cyst, and bronchiectasis], pleura (pleural effusion and pneumothorax), and mediastinum (lymphadenopathy). When a lung abnormality was present, laterality, distribution (upper, middle, and lower lung zone), and extent were also evaluated. When a pleural abnormality was identified, laterality and size of the abnormality were also assessed. When mediastinal lymphadenopathy was present, its location and size were also evaluated. Interobserver agreement between two independent reviewers was evaluated with κ statistics. RESULTS: In all, 17 thoracic MDCT studies from 17 individual pediatric patients [5 males (29%) and 12 females (71%); mean age: 7.4 y; SD: 3.7; range: 1 to 13 y] comprised the final study population. Among 17 thoracic MDCT studies, 11 studies (65%) were performed with intravenous contrast (IV) and the remaining 6 MDCT studies (35%) were obtained without IV contrast. Bilateral bronchiectasis (11/17; 65%) with a middle lung zone predominance (8/11; 73%) was the most frequently detected lung abnormality, followed by GGO in 9/17 patients (53%). Among 11 contrast-enhanced MDCT studies, the majority (9 patients, 82%) had mediastinal lymphadenopathy. There was excellent interobserver κ agreement between 2 independent reviewers for detecting abnormalities on thoracic MDCT studies (κ>0.90). CONCLUSION: Children with DOCK8 deficiency have characteristic thoracic MDCT findings, including bilateral bronchiectasis with a middle lung zone predominance, GGO, and mediastinal lymphadenopathy. When these characteristic thoracic MDCT findings are detected, although rare, DOCK8 deficiency should be considered as a possible underlying diagnosis in the pediatric population.

Thoracic MDCT findings of a combined congenital lung lesion: Bronchial atresia associated with congenital pulmonary airway malformation.

PURPOSE: To investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of pathologically proven combined congenital lung lesion consisting of bronchial atresia (BA) and congenital pulmonary airway malformation (CPAM) in children. MATERIALS AND METHODS: All pediatric patients (age ≤ 18 years) with a known pathological diagnosis of a combined BA-CPAM congenital lung lesion, who underwent thoracic MDCT studies from January 2011 to January 2021 were included. Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of abnormalities in the lung, including nodule, mass, cyst, ground-glass opacity, and consolidation. When a lung abnormality was present, the number, size, composition (solid, cystic, or combination of both), borders (well-circumscribed vs. ill-defined), contrast enhancement pattern (nonenhancement vs. enhancement), and location (laterality, and lobar distribution) were also evaluated. Interobserver agreement between two independent reviewers was evaluated with κ statistics. RESULTS: Eighteen contrast-enhanced thoracic MDCT studies from 18 individual pediatric patients (8 males (44%) and 10 females (56%); mean age: 4.9 months; SD: 2.6; range: 1-10 months) with a pathological diagnosis of combined BA-CPAM congenital lung lesion comprised the final study population. The most frequent MDCT finding of combined BA-CPAM congenital lung lesion in children was a solitary (18/18; 100%), well-circumscribed (18/18; 100%), both solid and cystic (17/18; 94%) lesion with nonenhancing (17/17; 100%) nodule, reflecting the underlying BA component, adjacent to a well-circumscribed multicystic mass (18/18; 100%), representing the underlying CPAM component. This combined congenital lung lesion occurred in all lobes with similar frequency. There was almost perfect interobserver κ agreement between the two independent reviewers for detecting abnormalities on thoracic MDCT studies (k = 0.98). CONCLUSION: The characteristic thoracic MDCT findings of a combined BA-CPAM congenital lung lesion are a solitary, well-circumscribed solid and multicystic mass, with a nonenhancing nodule, reflecting the BA component, adjacent to a cystic mass, representing the CPAM component. Accurate recognition of these characteristic MDCT findings of combined BA-CPAM congenital lung lesion has great potential to help differentiate this combined congenital lung lesion from other thoracic pathology in children.

Thoracic Multidetector Computed Tomography Angiography of Primary Pulmonary Vein Stenosis in Children: Evaluation of Characteristic Extravascular Findings.

PURPOSE: The purpose of this study was to investigate the extravascular thoracic multidetector computed tomography (MDCT) angiography findings of pediatric primary pulmonary vein stenosis (PVS) by comparing extravascular thoracic MDCT angiography findings in children with and without PVS. MATERIALS AND METHODS: All pediatric patients (age 18 y and below) with a known diagnosis of primary PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from July 2006 to December 2020 were included. A comparison group, comprised of age-matched and sex-matched pediatric patients without PVS who underwent thoracic MDCT angiography studies during the same study period, was also generated. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung (ground-glass opacity [GGO], consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis), pleura (pleural thickening, pleural effusion and pneumothorax), and mediastinum (lymphadenopathy and mass). When a thoracic abnormality was identified, the location and distribution of the abnormality (in relation to the location of PVS) were also evaluated. Extravascular thoracic MDCT angiography findings of pediatric patients with and without primary PVS were compared. Interobserver agreement between the 2 independent reviewers was evaluated with κ statistics. RESULTS: The study group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients with primary PVS (8 males [53%] and 7 females [47%]; mean age: 10.9 mo; SD: 11.7 mo; range: 1 to 48 mo). The comparison group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients without PVS (8 males [53%] and 7 females [47%]; mean age: 10.2 mo; SD: 11.5 mo; range: 1 to 48 mo). In children with primary PVS, the characteristic extravascular thoracic MDCT angiography findings were GGO (14/15; 93%), septal thickening (5/15; 33%), pleural thickening (14/15; 93%), and ill-defined, mildly heterogeneously enhancing, noncalcified soft tissue mass (14/15; 93%) following the contours of PVS in the mediastinum. There was excellent interobserver κ agreement between 2 independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (κ=0.99 for the study group and κ=0.98 for the comparison group). CONCLUSIONS: Children with primary PVS have characteristic extravascular thoracic MDCT angiography findings. In the lungs and pleura, GGO, septal thickening, and pleural thickening are common findings. Importantly, in the mediastinum, the presence of a mildly heterogeneously enhancing, noncalcified soft tissue mass in the distribution of PVS is a novel characteristic thoracic MDCT angiography finding unique to pediatric primary PVS. When this constellation of extravascular thoracic MDCT angiography findings is detected, although rare, primary PVS should be considered as a possible underlying diagnosis, especially in symptomatic children.

Thoracic Multidetector Computed Tomography Evaluation of Inflammatory Myofibroblastic Tumor of the Lung in Pediatric Patients in the Era of Modern Diagnosis.

PURPOSE: The purpose of this study was to investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of pathologically proven inflammatory myofibroblastic tumor (IMT) of the lung in children in the era of modern understanding based on refined pathologic diagnosis. MATERIALS AND METHODS: All pediatric patients (age 18 y and above) with a known pathologic diagnosis of IMT of the lung who underwent thoracic MDCT studies from May 2008 to December 2020 were included. Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of abnormalities in the lung (nodule, mass, cyst, ground-glass opacity, consolidation), pleura (pleural effusion, pneumothorax), and mediastinum and hilum (lymphadenopathy). When a lung abnormality was present, the number, size, composition (solid, cystic, or combination of both), location (laterality, lobar distribution, and intraparenchymal vs. pleural-based), borders (well-circumscribed vs. ill-defined), the presence and type of associated calcification (punctate, dense, curvilinear, or flocculent), the presence of associated cavitation, contrast enhancement pattern (homogeneous, heterogenous, central, or peripheral), and other associated findings (neural foramen involvement, anomalous vessels, mass effect, and invasion of adjacent thoracic structures) were also evaluated. Interobserver agreement between 2 independent reviewers was evaluated with κ statistics. RESULTS: In all, 12 thoracic MDCT studies from 12 individual pediatric patients (5 males [42%] and 7 females [58%]; mean age: 9.9 y; SD: 4.4 y; range: 2 to 16 y) comprised the final study population. All 12 thoracic MDCT studies (100%) were performed with intravenous contrast. The most frequent MDCT finding of IMT of the lung in children is a solitary (92%), pleural-based (83%), well-circumscribed (100%), solid (92%) mass with heterogenous contrast enhancement (100%), often with dense calcification (50%), which occurred in both lungs and all lobes with similar frequency. No pleural abnormality (pleural effusion, pneumothorax) or mediastinal abnormality (lymphadenopathy) was detected. In addition, although mass effect on adjacent thoracic structures was frequently seen (42%), no invasion, neural foramen involvement, or associated anomalous vessels was identified. There was excellent interobserver κ agreement between 2 independent reviewers for detecting abnormalities on thoracic MDCT studies (κ>0.95). CONCLUSIONS: IMT of the lung in children typically presents as a solitary, pleural-based, well-circumscribed, solid mass with heterogenous contrast enhancement, often with dense calcification, without significant laterality or lobar preference. In addition, pleural or mediastinal abnormalities are characteristically absent. These notable MDCT attributes of IMT of the lung are an important and novel finding, with great potential to help differentiate pediatric IMT of the lung from other thoracic masses in children.