Chest radiographic features of human metapneumovirus infection in pediatric patients.

BACKGROUND: Human metapneumovirus (HMPV) was identified in 2001 and is a common cause of acute respiratory illness in young children. The radiologic characteristics of laboratory-confirmed HMPV acute respiratory illness in young children have not been systematically assessed. OBJECTIVE: We systematically evaluated the radiographic characteristics of acute respiratory illness associated with HMPV in a prospective cohort of pediatric patients. MATERIALS AND METHODS: We included chest radiographs from children <5 years old with acute respiratory illness who were enrolled in the prospective New Vaccine Surveillance Network (NVSN) study from 2003 to 2009 and were diagnosed with HMPV by reverse transcription-polymerase chain reaction (RT-PCR). Of 215 HMPV-positive subjects enrolled at our tertiary care children's hospital, 68 had chest radiographs obtained by the treating clinician that were available for review. Two fellowship-trained pediatric radiologists, independently and then in consensus, retrospectively evaluated these chest radiographs for their radiographic features. RESULTS: Parahilar opacities were the most commonly observed abnormality, occurring in 87% of children with HMPV. Hyperinflation also occurred frequently (69%). Atelectasis (40%) and consolidation (18%) appeared less frequently. Pleural effusion and pneumothorax were not seen on any radiographs. CONCLUSION: The clinical presentations of HMPV include bronchiolitis, croup and pneumonia. Dominant chest radiographic abnormalities include parahilar opacities and hyperinflation, with occasional consolidation. Recognition of the imaging patterns seen with common viral illnesses like respiratory syncytial virus (RSV) and HMPV might facilitate diagnosis and limit unnecessary antibiotic treatment.

A rare accessory muscle in the hand--the flexor digitorum superficialis indicis.

Accessory muscles are easily overlooked during imaging evaluation. Although usually discovered incidentally, they are occasionally symptomatic. With increasing utilization of cross-sectional imaging, the radiologist should be prepared to readily identify these anomalous muscles. It is particularly important to distinguish these anatomical variants from soft-tissue tumors prior to invasive intervention, reserving biopsy and surgery for children who are symptomatic. This report discusses a case of a flexor digitorum superficialis indicis muscle, an extremely rare but well-described accessory muscle, presenting as a painful mass in a 15-year-old girl. The report includes the clinical presentation, radiologic findings, and the significance to management.

Second opinion interpretations by specialty radiologists at a pediatric hospital: rate of disagreement and clinical implications.

OBJECTIVE: The objective of our study was to identify whether a substantive difference exists between the imaging interpretations of radiologists at outside referring institutions and those of radiologists at a tertiary care children's hospital and whether such reinterpretation affects the clinical management of pediatric patients. MATERIALS AND METHODS: This retrospective chart review examined the diagnostic imaging reports of all pediatric patients referred to a tertiary care freestanding children's hospital over a 17-month period (January 1, 2009-May 31, 2010); 773 examinations met the inclusion criteria. The original and second interpretations were compared. A fellowship-trained pediatric radiologist and neuroradiologist categorized each case using the content of the two radiology reports as agreement versus minor or major disagreement, and the results were analyzed for statistical significance. A cohort of cases in which a final diagnosis could be confirmed was also analyzed to evaluate the accuracy of both interpretations. RESULTS: Disagreements were found in 323 of 773 reports (41.8%): 168 (21.7%) were major and 155 (20.0%), minor. Neurologic studies were most frequently requested for reinterpretation, 427 (55.2%), most commonly in the setting of trauma, 286 (67.0%). Among the 427 neuroimaging studies, major and minor disagreements occurred in 54 (12.6%) and 91 (21.3%) cases, respectively. Major disagreements most frequently observed were about the presence of fracture and hemorrhage. Among 305 body imaging cases, major and minor disagreements occurred in 99 (32.6%) and 57 (18.7%) cases, respectively. The most common setting for nontraumatic body imaging was concern for appendicitis (168/305 [55.1%]); this indication for imaging was responsible for 40.3% of major disagreements in nontraumatic abdominal imaging. Reinterpretation was rarely requested for radiographic studies (41/773 [5.3%]), which had major and minor disagreement rates of 36.6% and 17.1%, respectively. In the cohort of cases analyzed for final diagnosis, the second interpretation was more accurate than the original in 90.2% of cases with a p value of less than 0.0001. CONCLUSION: Our findings suggest that discrepancy rates for second interpretations in studies of pediatric patients transferred to tertiary care pediatric institutions are substantial. Although the original and second interpretations in the majority of cases were in agreement, major discrepancies were prevalent--12.6% and 32.6% of neuroimaging and body studies, respectively--and the second interpretations were significantly correlated with the final diagnosis. These results indicate that interpretations by subspecialty radiologists at a point-of-care facility provide important clinical information about the pediatric patient and should be recognized by payers as integral to optimal care.