Chronic avulsive injury of the deltoid insertion in adolescents: imaging findings in three cases

The clinical and imaging (magnetic resonance [MR] imaging, radiography, and bone scintigraphy) findings in three adolescent boys with chronic avulsive injury at the deltoid insertion are presented. MR imaging enabled the exclusion of findings suggestive of malignancy and the localization of abnormalities to the deltoid insertion site. Findings included cortical thickening and irregularity of the deltoid tubercle, with or without adjacent soft-tissue edema.

Utility of radiographs in the evaluation of pediatric upper airway obstruction

The evaluation of children with airway obstruction always involves a history and physical examination. The definitive diagnosis is most often made with microlaryngoscopy and bronchoscopy (MLB), and in cases of extrinsic compression, information is gained from magnetic resonance imaging. Although plain radiographs of the airway are often used as a primary diagnostic modality in children with airway obstruction, the accuracy of plain radiographs in predicting specific airway abnormalities has not previously been evaluated. This study was designed to correlate the findings of plain airway radiographs with the diagnosis made at the time of MLB. Medical records from 1991 to 1996 were reviewed to identify patients that had MLB and airway radiographs within 2 days of one another. One hundred forty-four cases were identified and divided into diagnostic categories. Statistical analysis showed a high sensitivity (>86%) for the accuracy of the radiologic diagnoses of exudative tracheitis, airway foreign body, and innominate artery compression. Laryngomalacia and tracheomalacia had a much lower sensitivity (5% and 62%, respectively). We believe that plain radiographic evaluation of the airway provides important information to the diagnostician. However, plain radiographs can be inaccurate and must be considered along with a history, physical examination, and clinical suspicion. Microlaryngoscopy and bronchoscopy remains the ultimate diagnostic test for airway disorders.

Optimizing contrast-enhanced abdominal CT in infants and children using bolus tracking

OBJECTIVE

Manual administration of IV contrast material results in unpredictable injection rates. Our purpose was to determine the effect of bolus tracking on overall abdominal helical CT scan quality, particularly on hepatic enhancement, in children with manually administered contrast media.

MATERIALS AND METHODS

We compared 33 abdominal helical CT scans of 29 children in whom bolus tracking was used with 22 CT scans of a control group of 21 children in whom bolus tracking was not used. All contrast material was administered by manual injection. Qualitative assessment was made of organ and vessel enhancement and overall scan appearance. Quantitative assessment using region-of-interest cursors was performed at three anatomic levels, and the results for the two groups of children were compared.

RESULTS

Qualitative comparison of enhancement parameters between the bolus tracking group (number given first) and the control group (number given second) yielded the following: splenic artifact in 9% versus 23% (p = .24); inferior vena cava flow artifact in 3% versus 27% (p = .01); scanning during the nephrographic phase in 89% versus 59% (p = .02); and good quality grade in 79% versus 64% (p = .23). Significantly greater hepatic enhancement (as measured in mean Hounsfield units) was achieved in the bolus tracking group than in the control group at the superior (48.5 versus 28.6; p < .001), middle (47.9 versus 32.3; p < .001), and inferior (48.2 versus 36.5; p = .01) levels. Hepatic enhancement increased significantly from the superior to the inferior level in the control group (p < .02), whereas enhancement was homogeneous in the bolus tracking group (p > .50).

CONCLUSION

Bolus tracking provides improved contrast enhancement, including significantly greater hepatic enhancement, during abdominal helical CT in children in whom the rate of injection of contrast material is unpredictable.

Chronic avulsive injuries of childhood

Children and adolescents are prone to avulsive injuries related to a combination of their propensity for great strength, ability to sustain extreme levels of activity, and immature growing apophyses. Appropriate interpretation of imaging studies showing chronic avulsive injuries is essential so that the irregularity and periostitis that can be associated with chronic avulsions is not misinterpreted as probable malignancy. This article reviews the chronic avulsive injuries of childhood.

Maximizing the usefulness of imaging in children with community-acquired pneumonia

In summary, imaging plays important roles in the diagnosis and treatment of children with community-acquired pneumonia. These roles include confirmation or exclusion of pneumonia, differentiation between viral and bacterial pneumonia, exclusion of other causes of symptoms, evaluation when the pneumonia fails to resolve, and evaluation of related complications.

Heterogeneous splenic enhancement patterns on spiral CT images in children: minimizing misinterpretation

PURPOSE

To (a) determine the appearances and timing of heterogeneous splenic enhancement at spiral computed tomography (CT) and (b) identify variables influencing heterogeneous splenic enhancement.

MATERIALS AND METHODS

Sequential isolevel (24-mAs) CT images of the spleen obtained at 6-second intervals after initiation of contrast material injection in 112 children (mean age, 4.5 years) were reviewed. Heterogeneity characteristics assessed included type, onset, maximum, and resolution. Relationship to variables (injection rate, age, splenomegaly) was assessed with the Fisher exact test.

RESULTS

Eighty-one of the 112 patients (72%) had transient heterogeneity: archiform (45 patients), diffuse (25 patients), and focal (11 patients). Mean times were as follows: initial visualization after onset of contrast material injection, 19.2 seconds; maximum heterogeneity, 27.3 seconds; and resolution, 47.4 seconds. Statistically significant relationships were seen between frequency of heterogeneity and injection rate (> or = 1 mL/sec, 82%; < 1 mL/sec, 50% [P = .001]), age (> 1 year, 76%; < or = 1 year, 46% [P = .04]), and splenomegaly (present, 20%; absent, 77% [P = .048]).

CONCLUSION

Heterogeneous splenic contrast enhancement is common, has several patterns of appearance, and is predictably encountered during the 70 seconds after the initiation of contrast material injection. Injection rate, age, and presence of splenic disease influence the frequency with which these artifacts are encountered.

Atypical presentation of Clostridium difficile colitis in patients with cystic fibrosis

OBJECTIVE

This report describes the unusual presentation of Clostridium difficile colitis in five patients with cystic fibrosis and the role of CT in first suggesting the correct diagnosis in this group of patients. Because of the absence of watery diarrhea and the presence of abdominal bloating and decreased stooling, cystic fibrosis patients with C. difficile colitis will be treated for stool impaction, meconium ileus equivalent, or distal intestinal obstruction syndrome. CT of the abdomen, performed in these five patients because of their lack of improvement after standard therapy for stool impaction, showed an extensive pancolitis later confirmed to be caused by C. difficile infection.

CONCLUSION

In patients with cystic fibrosis, imaging findings of a pancolitis should raise the possibility of C. difficile colitis despite the lack of watery diarrhea. Anticlostridial treatment can be initiated before bacteriologic confirmation is obtained.

The appearance and significance of extrapleural fluid after esophageal atresia repair

OBJECTIVE

The objective is to describe the appearance and evaluate the significance of postoperative extrapleural fluid collections in neonates who have undergone esophageal atresia repair in which an extrapleural surgical approach was used.

CONCLUSION

Extrapleural effusion in a neonate who has undergone repair of esophageal atresia by an extrapleural approach is associated with a high incidence of anastomotic leakage. Such patients may also be at increased risk for developing a delayed esophageal stricture. On chest radiography, these extrapleural effusions look like fluid in the pleural space.

Lymphoproliferative disorders: CT findings in immunocompromised children

OBJECTIVE

The objective was to evaluate the CT imaging appearance, distribution of disease, type of immunocompromised state, and outcome of children with Epstein-Barr virus-induced lymphoproliferative disorders.

MATERIALS AND METHODS

Medical records and imaging studies (from four tertiary children's medical centers) were reviewed for pathologically proven cases of lymphoproliferative disorders in patients less than 20 years old. Trends between the CT imaging appearance, distribution, and type of immunocompromised state and prognosis were noted and analyzed with Fisher's exact test.

RESULTS

Twenty-seven cases were identified (mean age, 7 years 8 months). Eighteen children had undergone solid organ transplantation (heart, n = 9; liver, n = 7; kidney, n = 2), and four had undergone bone marrow transplantation. Five patients had primary immunodeficiencies. The CT appearance of lymphoproliferative disorders varied and included lymphadenopathy, focal mass or masses, and diffuse infiltration and enlargement of organs without focal mass. The distribution of disease included abdomen (n = 17), chest (n = 10), neck (n = 8), and brain (n = 1). In eight of nine heart transplant recipients, the disease predominantly involved the chest and neck, whereas in all seven liver transplant recipients, the disease was isolated to the abdomen (p = .001). The overall mortality rate of 44% was less related to anatomic extent (multiorgan, 46%; localized, 43%) than to type of immune dysfunction (p = .001): bone marrow transplantation (100%), primary immunodeficiency (80%), heart transplantation (55%), liver transplantation (0%), and kidney transplantation (0%).

CONCLUSION

Lymphoproliferative disorders in children had a variable distribution, imaging appearance, and outcome. However, in recipients of solid organ transplants, the disease tended to occur in the anatomic region of the transplant. Mortality rates were more closely related to the type of underlying immune dysfunction than to distribution of disease.

Cavitary necrosis complicating pneumonia in children: sequential findings on chest radiography

OBJECTIVE

The objective of this study was to describe the sequential clinical and radiographic findings of cavitary necrosis complicating pneumonia in childhood.

MATERIALS AND METHODS

A study group of 17 children (mean age, 6 years) was identified by reviewing CT examinations of all patients who underwent CT of the chest to evaluate possible complications of pneumonia over a 3-year period. Children included in the study group were those who met the criteria for cavitary necrosis: loss of lung architecture, decreased enhancement, and multiple cavities with thin, nonenhancing walls. In the 17 identified cases, sequential chest radiographs were reviewed for visibility of a lung cavity. Long-term follow-up radiographs were evaluated for persistent abnormalities.

RESULTS

Ten of the 17 cases of cavitary necrosis seen on CT showed cavities at some time on radiography: one cavity was visible at the time of diagnosis on CT and nine were visible only later. All three cavities that were predominantly air-filled on CT were revealed by radiography, whereas 50% (7/14) of predominantly fluid-filled cavities were revealed by radiography. Eleven children underwent follow-up radiography more than 40 days after the diagnosis of cavitary necrosis. Radiographs of those 11 children showed clear lungs without pulmonary sequelae.

CONCLUSION

In children, cavitary necrosis is associated with severe illness; however, cases usually resolve without surgical intervention, and long-term follow-up radiography shows clear lungs without pulmonary sequelae. Evidence of cavitary necrosis complicating pneumonia is often seen on CT before or in the absence of findings on chest radiography.

Traumatic elbow effusions in pediatric patients: are occult fractures the rule?

OBJECTIVE

Elbow joint effusion with no fracture seen on radiographs of pediatric patients after acute trauma has become synonymous with occult fracture. This study evaluates the incidence of occult fractures in such cases as determined by findings on follow-up radiographs.

MATERIALS AND METHODS

Initial and follow-up radiographs were reviewed for 54 children (mean age, 7 years) with a history of trauma who had joint effusion but no identifiable fracture on initial radiographs. The presence of periosteal reaction or bony sclerosis on follow-up radiographs was considered to be evidence of occult fracture. Mean time between initial and follow-up radiographs was 18 days (range, 14-50 days).

RESULTS

Only nine (17%) of the 54 patients showed evidence of a healing occult fracture on follow-up radiographs. However, we found a statistically significant relationship (p = .001) between persistent joint effusion on follow-up radiographs and occult fracture. Seventy-eight percent of cases with occult fracture, versus 16% of cases without occult fracture, had persistent effusions.

CONCLUSION

Joint effusion without visualized fracture on initial radiographs after trauma does not correlate with the presence of occult fracture in most cases (83%). Therefore, joint effusion as revealed by radiography should not be considered synonymous with occult fracture.

The yield of CT of children who have complicated pneumonia and noncontributory chest radiography

OBJECTIVE

Our purpose was to investigate the usefulness of CT in evaluating children who do not respond appropriately to treatment for pneumonia, when chest radiography is noncontributory.

MATERIALS AND METHODS

Fifty-six contrast-enhanced CT scans were compared with radiographs obtained on the same day in children with complicated pneumonia. CT scans were evaluated for clinically significant findings that were not revealed by radiography: lung parenchymal complications (cavitary necrosis, abscess, decreased enhancement, bronchopleural fistula, or cavity suspected on radiography but not seen on CT), pleural complications (loculation, malpositioned chest tube), inaccurate estimation of cause of chest opacity on radiography (pleural versus parenchymal), bronchial obstruction, or pericardial effusion.

RESULTS

One hundred ten CT findings, not revealed by radiography, were seen on 56 CT scans (2.0 per CT scan): parenchymal complications (n = 40), pleural complications (n = 37), inaccurate estimation of cause of chest opacity on radiography (n = 20), pericardial effusion (n = 13). All CT scans showed at least one significant finding (100% yield) not seen on radiography.

CONCLUSION

In the evaluation of children with complicated pneumonia, CT often reveals clinically significant findings not apparent on radiography.

Pediatric hepatic imaging

Common indications for liver imaging in children include trauma, suspected mass, pre-liver transplantation, monitoring after liver transplantation, jaundice, or liver dysfunction. This article highlights areas where the pathology or imaging approach in children differs from that seen in adults. Topics covered include imaging of a suspected hepatic mass, neonatal jaundice, and segmented liver transplantation.