Posterior fossa dermoid cysts in association with Klippel-Feil syndrome: report of three cases.

Although the association of spinal lumbosacral dysraphism and congenital spinal dermoid tumors is well known, the association of craniocervical spinal anomalies and posterior fossa dermoids has only been recognized recently. Advances in imaging technology and awareness of the association likely contribute to an increase in recently reported cases.

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.

Midface anomalies in children.

A variety of congenital midface anomalies occur in children. High-resolution computed tomography (CT) and magnetic resonance (MR) imaging have proved helpful in determining the nature and extent of dysplasia, thereby facilitating treatment planning. A classification system has been developed that groups these anomalies into four categories based on embryogenesis and anatomic location. These categories comprise anomalies that are related to the nasal cavity, nasofrontal region, nasolacrimal apparatus, and craniofacial syndromes. CT is the imaging modality of choice in children with possible choanal atresia, pyriform aperture stenosis, or anomalies of the nasolacrimal duct (eg, nasolacrimal duct stenosis, dacryocystoceles). MR imaging is the modality of choice in patients with congenital midface masses (eg, dermoid and epidermoid cysts, nasal gliomas, encephaloceles) and craniofacial syndromes (eg, Apert syndrome, Crouzon syndrome, Treacher Collins syndrome). In many cases, however, both CT and MR imaging are required to adequately evaluate midface anomalies. Familiarity with the characteristic imaging features of these anomalies along with knowledge of midface embryogenesis and normal developmental anatomy is essential to prevent misinterpretation of anatomic variations that may simulate disease.

Screening sinus CT scans in pediatric bone marrow transplant patients.

OBJECTIVE: To determine how sinus disease noted on pre-bone marrow transplant (BMT) screening sinus computed tomography (CT) scans relates to subsequent development of clinical and/or radiographic sinusitis and correlates with overall prognosis. METHODS: A retrospective review of medical records, CT scans, and BMT database statistics was performed on all pediatric BMT recipients from January 1992 through December 1997. Fifty-four pre-BMT CT scans were performed on 51 children, aged from 2 months to 17 years. Sinus disease was staged according to criteria established by Lund and Kennedy [V.J. Lund, D.W. Kennedy, Ann. Otol. Rhinol. Laryngol. S167 (1995) 17-21.]. RESULTS: The average age of BMT recipients was 6.8 years. Most common oncologic diagnoses included acute myelogenous leukemia (37%), acute lymphoblastic leukemia (17%), and stage IV neuroblastoma (13%). Screening sinus CT scans were routinely performed 1-3 months prior to BMT. On pre-BMT CT scans 48% of the patients had no evidence of sinus disease, 25.9% mild disease, 9.3% moderate disease, and 16.7% severe disease. Two-thirds (66.7%) of patients with severe sinus disease on pre-BMT CT scans experienced clinical sinusitis post-BMT. In contrast, sinus symptoms were much less common (21.4%) in those with mild disease on CT scan. Overall, 39.3% of patients with sinus abnormalities on pre-BMT CT scans had clinical sinusitis during their post-BMT course, compared to 23.1% of those with normal CT scans pre-BMT. In addition, those patients demonstrating sinus disease on their pre-BMT CT scan were more likely to have radiographic sinusitis post-BMT (25.0%) than those with no disease (7.7%). Seventy-eight percent of those with severe sinusitis had died by 2-year follow up, compared to 69.2% of patients with normal CT scans pre-BMT. CONCLUSIONS: Severity of radiographic sinus disease on pre-BMT CT scans was noted to correlate with clinical and radiographic sinusitis later in the post-BMT course, and was associated with a trend toward decreased survival. Pre-BMT CT scans may be useful in determining which children need early and more aggressive intervention for clinical sinusitis post-BMT.

Pyloric ratio: efficacy in the diagnosis of hypertrophic pyloric stenosis.

We sought to define a weight independent, highly sensitive and specific measurement to diagnose hypertrophic pyloric stenosis. A retrospective review of 87 children was performed. We determined the pyloric ratio (wall thickness/pyloric diameter) and its relationship to weight and compared it to standard criteria. The average pyloric ratios in normal children and in those with hypertrophic pyloric stenosis were 0.205 and 0.325, respectively (P < 0.001). A pyloric ratio of 0.27 yielded a sensitivity and specificity of 96% and 94%, respectively. The pyloric ratio maintained a linear relationship to weight in normal patients and those with hypertrophic pyloric stenosis. We conclude the pyloric ratio can be a highly sensitive, specific, and weight independent indicator of hypertrophic pyloric stenosis.

Fetal surgery for myelomeningocele and the incidence of shunt-dependent hydrocephalus.

CONTEXT: Intrauterine closure of exposed spinal cord tissue prevents secondary neurologic injury in animals with a surgically created spinal defect; however, whether in utero repair of myelomeningocele improves neurologic outcome in infants with spina bifida is not known. OBJECTIVE: To determine whether intrauterine repair of myelomeningocele improves patient outcomes compared with standard care. DESIGN: Single-institution, nonrandomized observational study conducted between January 1990 and February 1999. SETTING: Tertiary care medical center. PARTICIPANTS: A sample of 29 study patients with isolated fetal myelomeningocele referred for intrauterine repair that was performed between 24 and 30 gestational weeks and 23 controls matched to cases for diagnosis, level of lesion, practice parameters, and calendar time. All infants were followed up for a minimum of 6 months after delivery. MAIN OUTCOME MEASURES: Requirement for ventriculoperitoneal shunt placement, obstetrical complications, gestational age at delivery, and birth weight for study vs control subjects. RESULTS: The requirement for ventriculoperitoneal shunt placement for decompression of hydrocephalus was significantly decreased among study infants (59% vs 91%; P = .01). The median age at shunt placement was also older among study infants (50 vs 5 days; P = .006). This may be explained by the reduced incidence of hindbrain herniation among study infants (38% vs 95%; P<.001). Following hysterotomy, study patients had an increased risk of oligohydramnios (48% vs 4%; P = .001) and admission to the hospital for preterm uterine contractions (50% vs 9%; P = .002). The estimated gestational age at delivery was earlier for study patients (33.2 vs 37.0 weeks; P<.001), and the birth weight of study neonates was less (2171 vs 3075 g; P<.001). CONCLUSIONS: Our study suggests that intrauterine repair of myelomeningocele decreases the incidence of hindbrain herniation and shunt-dependent hydrocephalus in infants with spina bifida, but increases the incidence of premature delivery.

Effect of intrauterine myelomeningocele repair on central nervous system structure and function.

BACKGROUND: It has been postulated that intrauterine myelomeningocele repair might improve neurologic outcome in patients with myelomeningocele. A total of 59 such procedures have been performed at Vanderbilt University. Preliminary results suggested that the degree of hindbrain herniation is reduced by intrauterine repair. In an attempt to further quantify the possible benefits of this surgery, a subset of these patients was brought back to Vanderbilt for study. METHODS: A group of 26 patients who had undergone intrauterine myelomeningocele repair underwent an extensive evaluation which included manual muscle testing, MR imaging and precise determination of the anatomic level of their lesions as well as multiple other tests. The results of this analysis were compared to those in 2 groups of historical controls. RESULTS: In this group of patients intrauterine myelomeningocele repair substantially reduced the incidence of moderate to severe hindbrain herniation (4 vs. 50%). The incidence of shunt-dependent hydrocephalus was more modestly reduced (58 vs. 92%). The average level of leg function closely matched the average anatomic level of the lesion in both the fetal surgery and control groups. CONCLUSION: The most dramatic effect of intrauterine repair appears to be on hindbrain herniation. A less dramatic, but significant, reduction in shunt-dependent hydrocephalus is also seen. Prospective patients should be cautioned not to expect improvement in leg function as the result of this surgery. The potential benefits of surgery must be carefully weighed against the potential risks of prematurity.

Intrauterine myelomeningocele repair reverses preexisting hindbrain herniation.

BACKGROUND: It has been reported that intrauterine myelomeningocele repair reduces the amount of hindbrain herniation normally seen in association with the Chiari type II malformation. It is not yet known, however, whether hindbrain herniation is prevented, or whether preexisting herniation is reversed. The following study was designed to elucidate this issue. METHODS: A series of 9 patients underwent intraoperative ultrasound examinations immediately prior to intrauterine myelomeningocele repair. These same patients were then evaluated postnatally using ultrasound and/or MRI. The degree of hindbrain herniation before and after repair was compared using a grading system devised by the authors. RESULTS: Eight patients had clear evidence of moderate to severe hindbrain herniation on intraoperative scans while one was mild. In contrast, on postnatal studies 5 of 9 patients had no evidence of hindbrain herniation, while the other 4 had only mild herniation. CONCLUSION: Intra-uterine myelomeningocele repair appears to reverse preexisting hindbrain herniation. It is postulated that continuous flow of cerebrospinal fluid through the neural placode is the force responsible for inducing migration of the cerebellum and brain stem downward through the foramen magnum. By interrupting that flow during gestation, intrauterine myelomeningocele repair enables the cerebellum and brain stem to resume a normal, or nearly normal, configuration.

Traumatic aortic injuries in children: radiologic evaluation.

OBJECTIVE: The purpose of this study was to evaluate the radiographic findings in children with traumatic aortic injuries and discuss the imaging techniques currently available for diagnosis. MATERIALS AND METHODS: A retrospective review of 10,886 children examined because of blunt trauma from 1987 to April 1996 identified seven patients (0.064%) who sustained traumatic aortic injuries. The mechanism of injury, location of aortic injury, additional injuries suffered, trauma scores, sequences of radiologic evaluation, imaging findings, treatment, and outcome were recorded for each child. RESULTS: Six children had pathologically proven aortic ruptures, and the remaining child had an intimal injury diagnosed with contrast-enhanced helical CT and confirmed with transesophageal echocardiography. All seven children were victims of motor vehicle accidents (six passengers, one pedestrian), all had injuries of the aortic isthmus, and all had additional severe injuries. The mean trauma score, injury severity score, and probability of survival were 14, 39, and 75%, respectively. Imaging techniques included chest radiography (n = 7), conventional CT (n = 1), helical CT (n = 3), aortography (n = 2), and transesophageal echocardiography (n = 3). The initial outcomes included death (n = 1), paraplegia (n = 1), paraparesis (n = 2), and recovery without morbidity (n = 3). CONCLUSION: Traumatic aortic injuries are rare in children. The most common findings on plain films are a left apical cap, pulmonary contusion, aortic obscuration, and mediastinal widening. Helical CT and transesophageal echocardiography can be used in the diagnosis of traumatic aortic injuries in children.

Imaging in pediatric urology.

A multitude of disorders of the genitourinary tract can occur in children. Although some entities may be diagnosed clinically, radiologic imaging is often necessary for diagnosis and management. The radiologic work-up has been discussed using a problem-oriented approach in five clinical situations: urinary tract infection, hydronephrosis or hydroureter, trauma, swollen scrotum, and hematuria. This discussion provides some general guidelines, although the evaluation of each child may need to be individualized depending on their specific clinical symptomatology.

Sensorineural hearing loss in children.

A variety of pathologic conditions cause sensorineural hearing loss in infants and children. Modern imaging techniques such as high-resolution computed tomography (CT) and magnetic resonance (MR) imaging have made it possible to identify a specific cause of pediatric hearing loss in many cases. A classification system has been developed that groups these abnormalities into three anatomic locations along the cochlear nerve: the labyrinth, the internal auditory canal, and the brain stem and cerebrum. Unenhanced high-resolution CT remains the imaging modality of choice in evaluating most cases of pediatric sensorineural hearing loss. In general, CT is the preferred modality in cases of trauma and nonacute congenital otic capsular dysplasias, whereas contrast material-enhanced MR imaging is preferred in cases of inflammatory and neoplastic disorders. Documented acute hearing loss in an older child or adolescent should also be studied with contrast-enhanced MR imaging. Reliable radiologic evaluation requires accurate clinical information as well as knowledge of normal inner ear anatomy and abnormal imaging findings.

Fluoroscopic evaluation of the ureters during intravenous urography.

In a prospective study, we assessed the usefulness of fluoroscopy in visualizing the ureters during intravenous urography. The percentage of ureter visualized was compared on radiographs acquired with and without fluoroscopic guidance. The length of ureter shown was significantly greater with fluoroscopic spot filming than with traditional urography. We recommend adjunctive fluoroscopy to enhance ureteral visualization during intravenous urography.