Growth plate injury at the base of the coracoid: MRI features.

PURPOSE: To assess the MRI features of growth plate injury at the base of the coracoid process. MATERIALS AND METHODS: Subjects were identified through retrospective search of our department imaging database and teaching files and the teaching files of two outside academic institutions. The coracoid base growth plate was examined with attention to widening, irregularity, abnormal signal intensity of the growth plate, and the presence of adjacent soft tissue edema. The apposing coracoid and scapular bony surfaces were examined for signal intensity and morphology. RESULTS: Shoulder MRIs in eight patients with coracoid base growth plate disturbances were retrospectively reviewed (7 males, 1 female, mean age 15 years). Growth plate injury manifested as widening, irregularity and increased signal, apposing bony marrow edema and hypertrophy, and surrounding soft tissue edema. Five subjects were athletes (football, archery, basketball, swimming, rugby), two had a history of neuromuscular disorders, and one subject presented after a fall. Clinical indications included: rule out labral tear (n = 3), rule out rotator cuff tear or fracture after fall (n = 1), nonspecific pain (n = 1), shoulder subluxation, rule out glenoid pathology (n = 1, patient with underlying neuromuscular disorder), muscular dystrophy with shoulder pain (n = 1), and impingement (n = 1). Coracoid growth plate injury was not suspected clinically in any of the patients. CONCLUSION: Awareness of the imaging appearance of coracoid base growth plate injury can aid in a more accurate diagnosis of shoulder MRI studies in young pediatric athletes. While uncommon, coracoid growth plate injury should be considered when assessing children with shoulder symptomatology.

The challenging ultrasound diagnosis of perforated appendicitis in children: constellations of sonographic findings improve specificity.

BACKGROUND: Rapid and accurate diagnosis of appendicitis, particularly with respect to the presence or absence of perforation, is essential in guiding appropriate management. Although many studies have explored sonographic findings associated with acute appendicitis, few investigations discuss specific signs that can reliably differentiate perforated appendicitis from acute appendicitis prior to abscess formation. OBJECTIVE: The purpose of our study was to identify sonographic findings that improve the specificity of US in the diagnosis of perforated appendicitis. Our assessment of hepatic periportal echogenicity, detailed analysis of intraperitoneal fluid, and formulation of select constellations of sonographic findings expands upon the literature addressing this important diagnostic challenge. MATERIALS AND METHODS: We retrospectively reviewed 116 abdominal US examinations for evaluation of abdominal pain in children ages 2 to 18 years from January 2008 to September 2011 at a university hospital pediatric radiology department. The study group consisted of surgical and pathology proven acute appendicitis (n = 51) and perforated appendicitis (n = 22) US exams. US exams without a sonographic diagnosis of appendicitis (n = 43) confirmed by follow-up verbal communication were included in the study population as the control group. After de-identification, the US exams were independently reviewed on a PACS workstation by four pediatric radiologists blinded to diagnosis and all clinical information. We recorded the presence of normal or abnormal appendix, appendicolith, appendiceal wall vascularity, thick-walled bowel, dilated bowel, right lower quadrant (RLQ) echogenic fat, increased hepatic periportal echogenicity, bladder debris and abscess or loculated fluid. We also recorded the characteristics of intraperitoneal fluid, indicating the relative quantity (number of abdominal regions) and quality of the fluid (simple fluid or complex fluid). We used logistic regression for correlated data to evaluate the association of diagnosis with the presence versus absence of each US finding. We conducted multivariable analysis to identify constellations of sonographic findings that were predictive of perforated appendicitis. RESULTS: The individual US findings of abscess/loculated fluid, appendicolith, dilated bowel and increased hepatic periportal echogenicity were significantly associated with perforated appendicitis when compared with acute appendicitis (P < 0.01). The sonographic observation of increased hepatic periportal echogenicity demonstrated a statistically significant association with perforated appendicitis compared with acute appendicitis (P < 0.01). The presence of complex fluid yielded a specificity of 87.7% for perforated appendicitis compared with the acute appendicitis group. The US findings of ≥2 regions or ≥3 regions with fluid had specificity of 87.3% and 99.0%, respectively, for perforated appendicitis compared with the acute appendicitis group. Select combinations of sonographic findings yielded high specificity in the diagnosis of perforated appendicitis compared with acute appendicitis. These constellations yielded higher specificity than that of each individual finding in isolation. The constellation of dilated bowel, RLQ echogenic fat, and complex fluid had the highest specificity (99.5%) for perforated appendicitis (P < 0.01). CONCLUSION: Our study demonstrates that identification of select constellations of findings using abdominal sonography, in addition to focused US examination of the right lower quadrant, can improve sonographic diagnosis of perforated appendicitis in the pediatric population.

Relative distribution of pertinent findings on portable neonatal abdominal radiographs: can we shield the gonads?

BACKGROUND: Shielding of the gonads is a dose-saving strategy in pediatric radiography and its use is the law in New York and the majority of other states. However, routine use of gonadal shields is controversial because of concerns that important diagnostic information can be obscured. OBJECTIVE: The purpose of this study was to assess the frequency and spatial distribution of key findings on portable neonatal abdominal radiographs. MATERIALS AND METHODS: We reviewed the 2,544 portable neonatal intensive care unit anteroposterior abdominal radiographs performed in 2010 at a university medical center, of which 962 were inadequately shielded. These 962 radiographs were reviewed by pairs of pediatric radiologists for the presence of findings in different regions, including bowel abnormalities, pneumatosis, free air, inguinal hernias, osseous abnormalities, and catheter/tube tips. RESULTS: The fewest pertinent findings were present below the level of the sacrosciatic notches (n = 181, 18.8%). Of the 853 abnormalities below the level of the iliac crests in our cohort, six were isolated to these regions, whereas others had concomitant abnormalities more superiorly. Of 35 radiographs with pneumatosis or suspected pneumatosis in the pelvis, 33 had pneumatosis in more superior regions. Suspected free air was never isolated to the pelvis. Osseous abnormalities were only present in the pelvis below the sacrosciatic notch, and 37.5% of lower extremity catheters terminated below the level of the sacrosciatic notches. CONCLUSION: Pertinent findings on neonatal intensive care unit abdominal radiographs are rarely isolated to the pelvic regions.

The efficacy of digital fluoroscopic image capture in the evaluation of vesicoureteral reflux in children.

BACKGROUND: In accordance with ALARA, minimizing radiation exposure associated with voiding cystourethrograms (VCUG) is of critical importance. Advances in fluoroscopic technology might help achieve this goal. OBJECTIVE: To determine the efficacy of fluoroscopic image capture compared to conventional digital radiographic spot (DRS) images in voiding cystourethrograms (VCUG) for the evaluation of vesicoureteral reflux (VUR) in children. MATERIALS AND METHODS: The study was a retrospective review of 65 VCUG examinations (130 kidney/ureter units). Each examination consisted of fluoroscopically captured spot (FCS) images and the corresponding DRS images. Each set of images was evaluated by three pediatric radiologists for the diagnosis of VUR for a total of 390 kidney/ureter units reviewed. Using the DRS image set as the reference standard, the efficacy of the FCS images for diagnosing reflux was determined. RESULTS: The diagnostic accuracy of the FCS images in terms of the binary characterization of reflux as negative or positive was 97.2% (379/390). The sensitivity of the FCS images was 92.6% (88/95); the specificity of the FCS images was 98.6% (291/295). CONCLUSION: Fluoroscopically captured images are adequate in documenting absence of VUR on VCUG examinations, obviating the need for radiographic spot images and resulting in reduction in radiation exposure.

A large struma ovarii tumor removed via laparoscopy in a 16-year-old adolescent.

Struma ovarii is rare ovarian tumor that is characterized by the presence of at least 50% thyroid tissue on histologic examination. This usually benign neoplasm is predominantly found in women between the ages of 40 and 60 years and infrequently in the pediatric age group. In the foregoing report, we present an unusual case of a large struma ovarii in a 16-year-old adolescent girl with abdominal pain and increasing abdominal girth. Removal of the mass was achieved via a laparoscopic approach. We conclude that the diagnosis of struma ovarii should be considered in adolescent girls presenting with large cystic ovarian masses and that a laparoscopic approach to management is the treatment of choice.

The relationship between alpha angle and resistive index of the femoral epiphysis in the normal and abnormal infant hip.

BACKGROUND: The arterial vascularity of the hip has been investigated in normal infants using duplex Doppler sonography. This study addressed the differences in hip vascularity in infants with respect to gender and acetabular morphology. OBJECTIVE: To determine whether there is a relationship between the resistive index of the vessels of the femoral chondroepiphysis and the alpha angle in normal infant hips and in those with developmental dysplasia of the hip. MATERIALS AND METHODS: We studied 76 hips (38 patients) with gray-scale and power Doppler US. The patients were referred because of a possible abnormal clinical hip examination or had risk factors for developmental dysplasia of the hip. The infants ranged in age from 1 day to 6 weeks. There were 13 boys and 25 girls. Gray-scale images were initially performed in the coronal and transverse planes to evaluate acetabular morphology, alpha angle and position of the femoral chondroepiphysis relative to the acetabulum. The hips were then examined with power Doppler US, in both sagittal and transverse planes, to identify arterial vessels within the femoral epiphysis. Resistive indices were then recorded from the spectral analysis in each vessel identified. Each examination was performed by one of five pediatric radiologists. Mixed model regression was used to assess the relationship between resistive index and alpha angle, age and gender. RESULTS: Of the 76 hips, 34 had an alpha angle of 60 degrees or greater and were classified as normal, 26 had an alpha angle between 50 degrees and 59 degrees and were classified as immature, and 13 had an alpha angle of less than 50 degrees and were either subluxed or dislocated at the time of examination. At least two vessels were documented in each femoral epiphysis except in three hips, in which no vessels could be documented because of technical factors. There was a statistically significant linear relationship between the alpha angle and resistive index, such that the resistive index tended to rise with increasing alpha angle (P=0.0022). In addition, female infants had a significantly higher average resistive index than the average resistive index in male infants with the same alpha angle (P=0.0005). CONCLUSION: There is a direct linear relationship between alpha angle and resistive index in the infant hip. Female infants have a higher average resistive index than male infants. We believe that these results might serve as a model for predicting an infant hip at risk of ischemia. In addition, the fact that lower resistive indices of the femoral epiphysis are associated with acetabular dysplasia might help explain the documented low incidence of avascular necrosis in untreated hip dysplasia.

Appendicitis in children: low-dose CT with a phantom-based simulation technique--initial observations.

PURPOSE: To retrospectively determine the accuracy of low-dose (20-mAs) computed tomography (CT) in the diagnosis of acute appendicitis in children by using a technique that enables the simulation of human CT scans acquired at a lower tube current given the image acquired at a standard dose. MATERIALS AND METHODS: Institutional review board approval was obtained, informed consent was not required, and the study was HIPAA compliant. The authors reviewed 100 standard-dose pediatric abdominal-pelvic CT scans (50 positive and 50 negative scans) obtained in 100 patients and corresponding simulated low-dose (20-mAs) scans. The standard-dose scans were obtained for evaluation in patients suspected of having appendicitis. Scans were reviewed in randomized order by four experienced pediatric radiologists. The patients with positive findings included 21 girls (mean age, 9.2 years) and 29 boys (mean age, 8.4 years). The patients with negative findings included 28 girls (mean age, 9.2 years) and 22 boys (mean age, 8.4 years). Simulation was achieved by adding noise patterns from repeated 20-mAs scans of a pediatric pelvis phantom to the original scans obtained with a standard tube current. Observers recorded their confidence in the diagnosis of appendicitis by using a six-point scale. Dose-related changes were analyzed with generalized estimating equations and the nonparametric sign test. RESULTS: There was a statistically significant (P < .001, sign test) decrease in both sensitivity and accuracy with a lower tube current, from 91.5% with the original tube current to 77% with the lower tube current. A low dose was the only statistically significant (P < .001) risk factor for a false-negative result. The specificity was unchanged at 94% for both the images obtained with the original tube current and the simulated low-dose images. The overall accuracy decreased from 92% with the original dose to 86% with the low dose. CONCLUSION: Preliminary findings indicate that it is feasible to optimize the CT dose used to evaluate appendicitis in children by using phantom-based computer simulations.

Metanephric adenoma in an 8-year-old child: case report and review of the literature.

Metanephric adenoma (MA) is a renal tumor that is rarely found in children. We present a case of MA that was incidentally discovered in an 8-year-old child on computed tomography. We also review the literature regarding this lesion in the pediatric population. There are certain imaging features of MA that may suggest the diagnosis preoperatively. Metanephric adenoma is often hyperechoic on sonography, hyperdense on noncontrast computed tomography scans, and of low signal intensity on T1- and T2-weighted magnetic resonance images. Nephron sparring surgery has been performed in several cases. However, the distinction of MA from other metanephric lesions as well as from Wilms' tumor and papillary renal cell carcinoma may not be readily apparent at the time of surgery.

Spontaneous development of bilateral subdural hematomas in an infant with benign infantile hydrocephalus: color Doppler assessment of vessels traversing extra-axial spaces.

We present an infant with macrocrania, who initially demonstrated prominent extra-axial fluid collections on sonography of the brain, compatible with benign infantile hydrocephalus (BIH). Because of increasing macrocrania, a follow-up sonogram of the brain was performed; it revealed progressive enlargement of the extra-axial spaces, which now had echogenic debris. Color Doppler US showed bridging veins traversing these extra-axial spaces, so it was initially thought that these spaces were subarachnoid in nature (positive cortical vein sign). However, an arachnoid membrane was identified superior to the cortex, and there was compression of true cortical vessels beneath this dural membrane. An MRI of the brain showed the extra-axial spaces to represent bilateral subdural hematomas. The pathogenesis of spontaneous development of the subdural hematomas, in the setting of BIH, is discussed. We also emphasize that visualizing traversing bridging veins through extra-axial spaces does not necessarily imply that these spaces are subarachnoid in origin.

Imaging evaluation of chest wall disorders in children.

This article discusses the imaging evaluation of chest wall disorders in children.

Assessment of vasculature using combined MRI and MR angiography.

OBJECTIVE: The purpose of this study was to compare combined cine gradient-recalled echo MRI and MR angiography with conventional angiography in the evaluation of the pulmonary vascular supply in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries. MATERIALS AND METHODS: Eleven patients who underwent both MRI and conventional angiography were retrospectively reviewed. Contiguous 2D cine gradient-recalled echo images (TR range/TE, 30-80/4.8; flip angle, 20 degrees or 30 degrees ) and 3D MR angiographic images (TR range/TE range, 3.8-5.0/1.3-2.0; acquisition time, 13-32 sec) using gadopentetate meglumine (0.1-0.2 mmol/kg) were obtained. The presence, size, and course of the pulmonary arteries (main, right, left) and major aortopulmonary collateral arteries (>/= 5 mm) were determined. Presence of minor collateral arteries (< 5 mm) was also noted. Results were compared with findings at conventional angiography. RESULTS: MRI showed all main (n = 4) and branch (n = 17) pulmonary arteries found at conventional angiography and showed the pulmonary confluence in five of six cases. MRI showed all major aortic collaterals (n = 22) with a highly significant correlation between MRI and conventional angiography measurements (r = 0.84, p < 0.001 [95% confidence interval, -0.35 to 0.40]). One coronary artery collateral was not shown on MRI examination. At MRI, 12 of 14 major and four of seven minor brachiocephalic artery collaterals were shown. MRI showed more minor aortic collaterals than angiography (22 vs 18 vessels, respectively). CONCLUSION: Combined cine gradient-recalled echo MRI and MR angiography is a reliable method for imaging pulmonary vascular supply in patients with these disorders. Additional prospective studies comparing MRI and conventional angiography may determine whether routine preoperative conventional angiography is required.

Idiopathic intraparenchymal hematoma of the liver in a neonate.

Hepatic hematomas in newborn infants are not frequently detected clinically, but are often found at perinatal autopsies. These hematomas of the liver are usually subcapsular in location. A variety of etiologies for such hematomas has been implicated, such as trauma, sepsis, and coagulopathies. We present a neonate who presented with jaundice and abdominal distention. Initial imaging studies revealed a large intraparenchymal lesion of the liver, which was at first thought to be suspicious for neoplasm; however, MRI showed the lesion to be hemorrhagic and follow-up sonographic studies showed total resolution of this lesion, compatible with hematoma. The intraparenchymal location and the idiopathic nature of this lesion distinguish this case from others previously reported.

Sclerosing stromal tumor of the ovary in a premenarchal female.

Sclerosing stromal tumor (SST) is a rare benign ovarian neoplasm of stromal origin with less than 100 cases reported in the literature. Unlike the other stromal tumors, thecomas and fibromas, which tend to occur in the fifth and sixth decades, sclerosing stromal tumors predominantly affect females in the second and third decades. Computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound findings have been described, but have not been reported previously in the pediatric literature. We present a case of SST of the ovary in a 10-year-old premenarchal female, the youngest patient to our knowledge reported in the literature, and describe the ultrasound and CT findings with pathologic correlation.