Nonenhanced limited CT in children suspected of having appendicitis: prospective comparison of attending and resident interpretations.

PURPOSE: To prospectively compare resident and attending radiologic interpretations of nonenhanced limited computed tomographic (CT) scans obtained in children suspected of having appendicitis. MATERIALS AND METHODS: Seventy-five consecutive children underwent nonenhanced limited CT for suspected appendicitis. The scans were prospectively interpreted by a resident and an attending radiologist, each unaware of the other's interpretation. The probability that the findings indicated a diagnosis of appendicitis, level of certainty in the interpretation, and presence of an alternate diagnosis were statistically analyzed. RESULTS: Nineteen children (25%) had appendicitis. The area under the receiver operating characteristic curve was not significantly different between residents (0.97 +/- 0.02) and attendings (0.95 +/- 0.04). The percentage agreement between residents and attendings was 91% (kappa = 0.73 +/- 0.095). The average level of certainty tended to be higher for attendings (93% +/- 15) than residents (89% +/- 12). The sensitivity, specificity, and accuracy of resident interpretations were 63%, 96%, and 88%, respectively, compared with those of attending interpretations--95%, 98%, and 97%, respectively. Residents and attendings noted alternate diagnoses in 30% of children without appendicitis. CONCLUSION: A high level of agreement exists between resident and attending radiologists in the interpretation of nonenhanced limited CT scans in children suspected of having appendicitis. Residents, however, tend to be less confident in their interpretations.

Appendicitis and alternate diagnoses in children: findings on unenhanced limited helical CT.

The objective of this manuscript is to review and illustrate the findings of appendicitis, and of alternate diagnoses that may clinically or radiographically simulate appendicitis, on unenhanced limited CT in children. Potential pitfalls in unenhanced limited CT interpretation of pediatric patients will also be discussed.

Swelling at the angle of the mandible: imaging of the pediatric parotid gland and periparotid region.

The pediatric parotid gland and periparotid region are subject to a variety of lesions and are most often evaluated with ultrasonography (US), contrast material-enhanced computed tomography (CT), and magnetic resonance (MR) imaging. US may be used to assess the size of the parotid gland, distinguish diffuse from focal disease, assess vascularity and adjacent vascular structures, distinguish cystic from solid lesions, and guide fine-needle aspiration. However, further evaluation with CT or MR imaging may be needed to better define the nature and extent of disease. CT is the imaging modality of choice for most pediatric parotid disease (including acute inflammation, abscess, calculi, and major salivary duct obstruction) and most solid masses and may obviate sedation. However, a mass associated with facial nerve symptoms should be evaluated with MR imaging because it is the only modality that can consistently demonstrate the facial nerve. Findings at US, CT, and MR imaging allow localization of parotid lesions and may suggest a specific cause. Clinical information, familiarity with normal parotid anatomy at various stages of its development, and knowledge of the imaging characteristics of parotid and periparotid lesions are essential for appropriate radiologic evaluation. This information can be used to guide therapy and plan a surgical approach.

In vivo visualization of pyloric mucosal hypertrophy in infants with hypertrophic pyloric stenosis: is there an etiologic role?

OBJECTIVE: Infantile hypertrophic pyloric stenosis (IHPS) is a common condition which presents in infants at 2-12 weeks of postnatal life, and whose cause remains obscure. Multiple associated abnormalities have been recognized within the external hypertrophied pyloric muscle layer, but the internal component of the pyloric mucosa has received scant attention in the literature to date. Our purpose in this study was to show that pyloric mucosal redundancy is a constant finding in infants with IHPS, to discuss its possible cause, and to explore the hypothesis of a relationship between pyloric mucosal redundancy and the development of IHPS. MATERIALS AND METHODS: We identified 102 consecutive infants with surgically confirmed IHPS and determined the thickness of the pyloric mucosa compared with the thickness of the surrounding hypertrophied muscle. Fifty-one infants who did not have pyloric stenosis served as controls. RESULTS: Mean mucosal thickness in patients with IHPS approximated mean muscle thickness, with a ratio of 0.89. In infants with IHPS, the pyloric mucosa constitutes approximately one third of the cross-sectional diameter of the pyloric mass and fills and obstructs the pyloric canal. CONCLUSION: Mucosal redundancy is a constant associated finding in IHPS. Although the origin of the redundancy and a cause-and-effect relationship are difficult to establish, our findings support the hypothesis that hypergastrinemia may be implicated in the pathogenesis of IHPS, and suggest that mucosal thickening could be implicated as one of the initiating factors in its development.

Unenhanced limited CT of the abdomen in the diagnosis of appendicitis in children: comparison with sonography.

OBJECTIVE: The purpose of this investigation is to determine the sensitivity, specificity, and accuracy of unenhanced limited CT of the abdomen in children with suspected appendicitis and compare these results with graded compression sonography. MATERIALS AND METHODS: Seventy-six children underwent unenhanced limited CT over a 11-month period for evaluation of suspected appendicitis. A historical cohort of 86 consecutive children who had undergone graded compression sonography was identified. Results were correlated with surgical, pathologic, chart, and clinical follow-up data. The sensitivity, specificity, accuracy, rate of alternate diagnosis, time to perform examinations, and charge at our institution were determined for unenhanced limited CT and sonography. RESULTS: Sensitivity, specificity, and accuracy for unenhanced limited CT were 97%, 100%, 99%, respectively, and were 100%, 88%, 91%, respectively, for sonography. Alternate diagnoses were suggested in 35% and 28% children without appendicitis who had unenhanced limited CT and sonography, respectively. Unenhanced limited CT required 5 min and sonography required 20-30 min to perform. The charge at our institution was $408 for unenhanced limited CT and $295 for sonography. CONCLUSIONS: CT can be performed rapidly in children without IV, oral, or rectal contrast medium. Unenhanced limited CT and sonography are highly sensitive, specific, and accurate in the evaluation of children with suspected appendicitis.

Pediatric renal masses: Wilms tumor and beyond.

A variety of pediatric renal masses may be differentiated from Wilms tumor on the basis of their clinical and imaging features. Wilms tumor is distinguished by vascular invasion and displacement of structures and is bilateral in approximately 10% of cases. Nephroblastomatosis occurs most often in neonates and is characterized by multiple bilateral subcapsular masses, often associated with Wilms tumors. Renal cell carcinoma is unusual in children except in association with von Hippel-Lindau syndrome and typically occurs in the 2nd decade. Mesoblastic nephroma is the primary consideration in a neonate with a solid renal mass. Multilocular cystic renal tumor is suggested by a large mass with multiple cysts and little solid tissue. Clear cell sarcoma is distinguished by frequent skeletal metastases, and rhabdoid tumor is distinguished by its association with brain neoplasms. Angiomyolipoma frequently contains fat and is associated with tuberous sclerosis. Renal medullary carcinoma occurs in patients with sickle cell trait or hemoglobin SC disease and manifests as an infiltrative mass with metastases. Ossifying renal tumor of infancy is differentiated from mesoblastic nephroma by the presence of ossified elements. Metanephric adenoma lacks specific features but is always well defined. Renal lymphoma is characterized by multiple homogeneous masses, often with associated adenopathy.

Appendicolith revealed on CT in children with suspected appendicitis: how specific is it in the diagnosis of appendicitis?

OBJECTIVE: The purpose of this study was to determine the sensitivity, specificity, and positive and negative predictive values of a diagnosis of appendicitis when CT without enteric contrast material reveals an appendicolith in children with suspected appendicitis. MATERIALS AND METHODS: A retrospective review of children who underwent abdominal CT for suspected appendicitis over a 25-month period was performed to identify patients with an appendicolith. An age-matched group of patients examined for trauma served as controls. RESULTS: CT was performed in 104 children. Appendicitis was present in 60 (58%) of 104 children; 39 (65%) of 60 had an appendicolith. Appendicitis was not present in 44 (42%) of 104; six (14%) of 44 had an appendicolith. An appendicolith detected on CT had a sensitivity of 65% and a specificity of 86% for the radiologist diagnosing appendicitis. An appendicolith had a positive predictive value of 74% and a negative predictive value of 26%. Among the control population, two (3%) of 74 children had an appendicolith. This number was statistically significant compared with children in the study group with an appendicolith and abdominal pain, but without appendicitis (p = 0.02). CONCLUSION: Although an appendicolith is significantly associated with appendicitis, the detection of an isolated appendicolith on CT is not sufficiently specific to be the sole basis for the diagnosis of acute appendicitis.

Experimental study of mortality and morbidity of contrast media and standardized fecal dose in the peritoneal cavity.

BACKGROUND: The use of radiographic contrast media in the setting of possible bowel ischemia and potential perforation is known to be associated with increased clinical risk. However, there is a lack of controlled studies using a standard native fecal load to define and compare the intrinsic mortality and morbidity among options of contrast media currently available to the radiologist. We have compared the mortality and gross and histopathologic morbidity of a standard intraperitoneal native fecal dose in the guinea pig, using barium, two iodinated media, saline and air. MATERIALS AND METHODS: The study was performed on adult Hartley guinea pigs. A standard native fecal solution with a colony count of 10(8) aerobes and 2 x 10(7) anaerobes was prepared, and the LD50 of intraperitoneal injection of the solution was determined. The standard solution at the LD50 dose was then used to compare the mortality and morbidity when commercial barium sulfate (18% w/v), Conray 30 (iothalamate meglumine 30%), 1:1 dilution of Conray 30 with sterile water, termed Conray "15" (iothalamate meglumine 15%), saline and air, were added to the intraperitoneal injection of the fecal solution in five groups of 20 animals each. Mortality and acute (96 h) and chronic (30 days) gross and histopathology were assessed and graded according to a standard system and analyzed statistically. RESULTS: Barium was significantly more deleterious than the dilute water-soluble iodinated media, saline and air. Mortality occurred within 24 h in the barium group and within the initial 48 h in all groups as follows: barium 19/20 (95%); Conray 30 16/20 (80%); Conray "15" 7/20 (35%); saline 0; air 0. Acute gross and histopathology showed extensive grade 4 lesions in 19/19 barium animals; less severe lesions were present in a lesser percentage of the animals in the other four groups. Entirely chronic lesions were present only in the single surviving barium animal and were non-significant (< 400 microns) or absent in the other four groups. CONCLUSIONS: In our study, barium incurred the most significant deleterious short and long-term effects in the setting of fecal peritonitis. Dilute water-soluble media offer a much greater margin of safety. Saline under sonographic guidance is less deleterious than any of the positive radiographic contrast media. However, in our study, air was the safest contrast medium in the setting of peritoneal soiling.

Bartonella spp. isolated from wild and domestic ruminants in North America.

Bartonella species were isolated from 49% of 128 cattle from California and Oklahoma, 90% of 42 mule deer from California, and 15% of 100 elk from California and Oregon. Isolates from all 63 cattle, 14 deer, and 1 elk had the same polymerase chain reaction/restriction fragment length polymorphism profiles. Our findings indicate potential for inter- and intraspecies transmission among ruminants, as well as risk that these Bartonella spp. could act as zoonotic agents.

Implications of early sonographic evaluation of parapneumonic effusions in children with pneumonia.

OBJECTIVE: To devise a clinically relevant grading system for the sonographic evaluation of parapneumonic effusions, and to evaluate length of hospital stay as a function of treatment approach and sonographic grades. METHODS: Chest sonograms of 46 pediatric patients diagnosed with empyemas and admitted to two medical centers in the last 8 years were retrospectively evaluated using a grading system based on the degree of fibrinous organization within the parapneumonic effusions. Hospital charts were reviewed to determine the method of treatment and length of hospital stay. Patients were divided into two treatment groups: nonoperative (n = 26) (antibiotics alone, or combined with thoracentesis, or tube thoracostomy) and operative (n = 20) (open decortication, or video thoracoscopy and pleural debridement). Patients in the nonoperative group were further subdivided into two groups: those who received antibiotics alone (n = 11) and those who received antibiotics plus nonoperative drainage thoracentesis and/or tube thoracostomy (n = 15). Within each treatment group, patients were subdivided into two ultrasound grades: low (no evidence of organization) and high (evidence of organization such as fronds, septations, or loculations). Student's t test was performed to compare the lengths of hospital stay for each of the treatment groups and ultrasound grades. RESULTS: The length of hospitalization was no different for patients with low-grade ultrasounds in the nonoperative (9.8 days) and operative groups (8.0 days). In contrast, length of hospitalization was significantly shorter for patients with high-grade sonograms in the operative group (8.6 days), when compared with the nonoperative group (16.4 days). Length of hospitalization for patients in the nonoperative group with high-grade sonograms was significantly longer (16.4 days) than for those with low-grade ultrasounds (9.8 days). Furthermore, when the nonoperative patients were divided into an antibiotics alone group and a nonoperative drainage group, the patients with low-grade sonograms had no difference in the length of hospitalization (9.0 days vs. 10.4 days), whereas those patients with high-grade sonograms in the nonoperative drainage group had a significantly longer hospitalization (19.9 days) than the antibiotics alone (high-grade) group (11.4 days). CONCLUSIONS: Patients with a low-grade sonogram had similar length of hospitalization if treated with either nonoperative or operative measures. Patients with high-grade sonograms had significantly shorter length of hospitalization when treated with decortication. Our retrospective study suggests that patients with high-grade ultrasound studies treated nonoperatively do not benefit from pleural drainage procedures or chest tube placement. This study demonstrates the usefulness of early sonographic evaluation of parapneumonic effusions. A prospective study evaluating the usefulness of sonographic assessment of severity of disease in the treatment of children with parapneumonic effusions is warranted on the basis of our retrospective data.

Retroperitoneal pulmonary sequestration: imaging findings, histopathologic correlation, and relationship to cystic adenomatoid malformation.

OBJECTIVE: Retroperitoneal bronchopulmonary sequestrations are rare congenital lesions that have been increasingly reported as incidental findings in utero. We present our case material of congenital retroperitoneal sequestration, discuss the reported imaging and histopathologic characteristics of this entity, and provide an approach to subsequent clinical and surgical management. CONCLUSION: Our data suggest that the imaging findings in retroperitoneal sequestration are characteristic and that faulty mesenchymal induction of pulmonary tissue within the retroperitoneum renders internal development into cystic adenomatoid malformation the rule rather than the exception. In the typical case, surgical removal is nonemergent.

Hypertrophic pyloric stenosis in the infant without a palpable olive: accuracy of sonographic diagnosis.

PURPOSE: To evaluate the accuracy of sonography for both diagnosis and exclusion of pyloric stenosis in the infant with nonbilious vomiting without a palpable olive and to clarify the relationship between infant age and size and the dimensions of the hypertrophic pylorus. MATERIALS AND METHODS: The sonograms of 152 infants with suspected pyloric stenosis were evaluated. The prospective diagnoses were categorized as pyloric stenosis, normal pylorus, and pylorospasm with potential to progress to pyloric stenosis. Positive findings were confirmed at surgery; negative findings were confirmed by means of chart review. RESULTS: Sensitivity, specificity, and accuracy of sonography in determination of appropriate surgical referral were 100%. A significant (P < .05) correlation was found between the size of the hypertrophied muscle and the age of the patient at initial examination. CONCLUSION: Sonography is highly sensitive and, in this patient population, highly specific, and by virtue of direct visualization of the pyloric muscle, it is the method of choice for both diagnosis and exclusion of pyloric stenosis.

Experience with the illuminated endotracheal tube in the prevention of unsafe intubations in the premature and full-term newborn.

OBJECTIVE: To determine whether an endotracheal tube modified by incorporation of a fiberoptic strand in the wall and connected to a light source could be safely and reliably positioned in premature and full-term newborns using transdermal siting of a bright spot on the skin at the suprasternal notch of the chest wall. METHODS: All newborns in the Vanderbilt Neonatal Intensive Care Unit who were candidates for intubation by established clinical criteria, who were not already intubated, were candidates for the study. We defined optimal placement of the endotracheal tube to be one with the tip of the tube below the first thoracic vertebral body and no less than 0.5 cm above the carina or at T-4 (if the carina could not be seen on the radiograph). A light source was connected to the fiberoptic strand and the endotracheal tube positioned so that a circle of light was visible on the skin of the chest wall at the suprasternal notch. RESULTS: In all 22 placements, the tube tip was below the larynx and above the carina. In 20 of the placements, the position was optimal between T-1 and T-4, whereas in the other 2 the tube tip was high between the larynx and the thoracic inlet. This system required that an endotracheal tube 0.5 mm smaller than usually used be utilized because of the slight increase in outer diameter due to the fiberoptic strand. Conventional suction catheters were used in this study. CONCLUSIONS: This study has shown that the illuminated endotracheal tube is a reliable device for accurate positioning in premature and full-term newborns using transdermal siting of a bright spot on the skin at the suprasternal notch.

An evaluation of abdominal staging procedures performed in pediatric patients with advanced Hodgkin's disease: a report from the Childrens Cancer Study Group.

Forty-nine children and adolescents underwent staging laparotomy in the course of a cooperative group (CCG) study of advanced Hodgkin's disease (HD). The purpose of the study was to evaluate the toxicity of a regimen of 12 cycles of doxorubicin, bleomycin, vinblastine, and imidazole carboxamide (ABVD) plus 2,100 cGy regional irradiation in patients with stage III-IV disease. Review of the biopsies and specimens from these 49 laparotomies identified distinct patterns of abdominal involvement and permitted an evaluation of the importance of different aspects of the staging procedure and an assessment of the value of non-invasive techniques in determining the extent of abdominal disease. The major observations from these studies were: (1) computed tomography (CT) and gallium 67 scans (GA) were specific (few false positives), but not sensitive, indicators of abdominal disease; (2) negative findings at laparotomy in 29 patients permitted a contraction of the abdominal radiation fields with no subsequent abdominal recurrence in these patients; (3) in five patients, stage IV status was established only by laparotomy and open hepatic biopsy; (4) all patients with lower abdominal or pelvic involvement also had upper abdominal node or splenic involvement; (5) involvement of splenic hilar nodes was a sensitive predictor of splenic involvement; (6) disease in the inferior paraaortic nodes accurately predicted the presence of more distal disease, ie, in the iliac or pelvic node groups; and (7) in a limited experience, transposition of the ovaries protected ovarian function from the effects of pelvic irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Pediatric chest disease: evaluation by computerized tomography, magnetic resonance imaging, and ultrasonography.

The initial method for evaluating pediatric chest disease remains the plain chest roentgenogram. When more precise definition of chest disease is required, computerized tomography (CT), magnetic resonance imaging (MRI), or ultrasonography (US) may be useful. In general, CT offers the widest spectrum of applicability. MRI is especially useful because no ionizing radiation is used and images can be acquired in multiple planes. MRI is most valuable when vascular anatomy needs to be defined or when tumor invasion of the spinal canal is suspected. US is helpful in evaluating diseases of the pleura and for characterizing and localizing pleural fluid and masses. US can differentiate normal thymus from other anterior mediastinal masses. Doppler techniques are valuable in evaluating suspected pulmonary sequestration and identifying the feeding vessel.