Linda Vachon

Sclerosing Bone Dysplasias: Review and Differentiation from Other Causes of Osteosclerosis

Sclerosing bone dysplasias are skeletal abnormalities of varying severity with a wide range of radiologic, clinical, and genetic features. Hereditary sclerosing bone dysplasias result from some disturbance in the pathways involved in osteoblast or osteoclast regulation, leading to abnormal accumulation of bone. Several genes have been discovered that, when disrupted, result in specific types of hereditary sclerosing bone dysplasia (osteopetrosis, pyknodysostosis, osteopoikilosis, osteopathia striata, progressive diaphyseal dysplasia, hereditary multiple diaphyseal sclerosis, hyperostosis corticalis generalisata), many of which exhibit similar pathologic mechanisms involving endochondral or intramembranous ossification and some of which share similar underlying genetic defects. Nonhereditary dysplasias include intramedullary osteosclerosis, melorheostosis, and overlap syndromes, whereas acquired syndromes with increased bone density, which may simulate sclerosing bone dysplasias, include osteoblastic metastases, Paget disease of bone, Erdheim-Chester disease, myelofibrosis, and sickle cell disease. Knowledge of the radiologic appearances, distribution, and associated clinical findings of hereditary and nonhereditary sclerosing bone dysplasias and acquired syndromes with increased bone density is crucial for accurate diagnosis.

Racial Differences in Growth Patterns of Children Assessed on the Basis of Bone Age

PURPOSE To collect up-to-date data in healthy children to create a digital hand atlas (DHA) that can be used to evaluate, on the basis of the Greulich and Pyle atlas method, racial differences in skeletal growth patterns of Asian, African American, white, and Hispanic children in the United States. MATERIALS AND METHODS This retrospective study was HIPAA compliant and approved by the institutional review board. Informed consent was obtained from all subjects or their guardians. From May 1997 to March 2008, a DHA containing 1390 hand and wrist radiographs obtained in male and female Asian, African American, white, and Hispanic children with normal skeletal development was developed. The age of subjects ranged from 1 day to 18 years. Each image was read by two pediatric radiologists working independently and without knowledge of the subjects chronologic age, and evaluation was based on their experience with the Greulich and Pyle atlas. Statistical analyses were performed with the paired-samples t test and analysis of variance to study racial differences in growth patterns. P <or= .05 indicated a significant difference. RESULTS Bone age (P </= .05) was significantly overestimated in Asian and Hispanic children. These children appear to mature sooner than their African American and white peers. This was seen in both male and female subjects, especially in girls aged 10-13 years and boys aged 11-15 years. CONCLUSION Ethnic and racial differences in growth patterns exist at certain ages; however, the Greulich and Pyle atlas does not recognize this fact. Assessment of bone age in children with use of the Greulich and Pyle atlas can be improved by considering the subjects ethnicity.

Ossification centre of the hyoid bone in DiGeorge syndrome and tetralogy of Fallot

The incidence of radiographic visibility of the ossification centre of the body of the hyoid bone in radiographs taken during the first month of life was analysed for 34 autopsied infants: 16 with DiGeorge syndrome (DGS), 14 with tetralogy of Fallot (TOF), four with interrupted aortic arch (IAA) and a further 13, surviving infants with non-DGS TOF or non-DGS IAA. The incidence of visible hyoid ossification centre (HOC) was 75.7% in a control series of infants with neither congenital heart disease (CHD) nor DGS. Autopsied patients with DGS, TOF without DGS, and IAA without DGS showed a significantly low incidence of visible HOC. Infants with TOF (and possibly those with IAA) who did not have DGS and who did not die during infancy showed a normal incidence of visible HOC in radiographs taken during the first post-natal month. Radiological visibility of the HOC in the first post-natal month appears useful in the diagnosis of DGS and forms of CHD often seen in association with DGS and in assessing prognosis of neonates with certain types of CHD.

Pediatric Tuberculosis: Clinical Presentation and Contact Investigation at anUr ban Medical Center

Objective: (A) To characterize the clinical presentation of pediatric tuberculosis in Los Angeles County; (B) to determine the efficacy of contact investigation in identifying a source case for children with tuberculosis. Methods: We reviewed the medical records, chest radiograph and Tuberculosis Control records of 34 children (age <15 years) evaluated at Los Angeles County from January 1992 through December 1993. Results: All patients were hispanic. The mean age was 2.2 years. Thirty-three patients (97%) had intrathoracic disease. Eighteen patients (53%) were symptomatic and the most common symptoms were fever and cough. The contact investigation revealed only 4 patients (2%) to be adult source cases with active tuberculosis. Conclusion: The clinical features of pediatric tuberculosis in Los Angeles County confirm results previously reported in other parts of the US. In contrast, the identification of adult source cases is suboptimal. Improved methods of contact tracing are needed when evaluating children with tuberculosis.

Urinary Tract Infections in a Neonatal Intensive Care Unit

OBJECTIVE Our aim was to describe laboratory findings and imaging results for neonatal patients diagnosed with urinary tract infection (UTI). STUDY DESIGN Medical records were reviewed for infants diagnosed with UTI in a single neonatal intensive care unit (NICU) over a 13-year period. RESULTS Of the 8,241 patients admitted to the NICU during the study period, 137 infants were diagnosed with UTI. Imaging was reviewed for 101 patients. Renal pelvis dilation was found in 34% of patients and vesicoureteral reflux was found in 21%. Renal pelvis dilation was not associated with reflux (OR: 0.53 [95% CI: 0.18-1.5]). The sensitivity of urinalysis to detect a positive culture was 76%, and the specificity was 41%. Tests of cure for bacterial infections were uniformly negative. CONCLUSION Renal pelvis dilation was common but not associated with reflux among NICU patients diagnosed with UTI. Diagnostic criteria in this population are not well defined, and guidelines are needed for diagnosis and management of UTIs in NICU patients.

Real-time ultrasonography of arterial IVH in preterm infants

The vascular origin of intraventricular hemorrhage in premature infants is controversial and has been variously attributed to arteries, veins, arterioles, capillaries, or sinusoids that may be found in the vicinity of the ganglionic eminence. The clinical histories and serial ultrasound images are reported from 2 patients with intraventricular hemorrhage of arterial (high pressure) origin that were captured on real-time ultrasonography as they occurred.

An online real-time DICOM web-based computer-aided diagnosis system for bone age assessment of children in a PACS environment

Bone age assessment is a radiological procedure to evaluate a childs bone age based on his or her left-hand x-ray image. The current standard is to match patients hand with Greulich & Pyle hand atlas, which is outdated by 50 years and only uses subjects from one region and one ethnicity. To improve bone age assessment accuracy for todays children, an automated race- and gender-specific bone age assessment (BAA) system has been developed in IPILab. 1390 normal left-hand x-ray images have been collected at Childrens Hospital of Los Angeles (CHLA) to form the digital hand atlas (DHA). DHA includes both male and female children of ages one to eighteen and of four ethnic groups: African American, Asian American, Caucasian, and Hispanic. In order to apply DHA and BAA CAD into a clinical environment, a web-based BAA CAD system and graphical user interface (GUI) has been implemented in Women and Childrens Hospital at Los Angeles County (WCH-LAC). A CAD server has been integrated in WCHs PACS environment, and a clinical validation workflow has been designed for radiologists, who compare CAD readings with G&P readings and determine which reading is more suited for a certain case. Readings are logged in database and analyzed to assess BAA CAD performance in a clinical setting. The result is a successful installation of web-based BAA CAD system in a clinical setting.

Bone age assessment in Hispanic children: digital hand atlas compared with the Greulich and Pyle (G&P) atlas

Bone age assessment is most commonly performed with the use of the Greulich and Pyle (G&P) book atlas, which was developed in the 1950s. The population of theUnited States is not as homogenous as the Caucasian population in the Greulich and Pyle in the 1950s, especially in the Los Angeles, California area. A digital hand atlas (DHA) based on 1,390 hand images of children of different racial backgrounds (Caucasian, African American, Hispanic, and Asian) aged 0-18 years was collected from Childrens Hospital Los Angeles. Statistical analysis discovered significant discrepancies exist between Hispanic and the G&P atlas standard. To validate the usage of DHA as a clinical standard, diagnostic radiologists performed reads on Hispanic pediatric hand and wrist computed radiography images using either the G&P pediatric radiographic atlas or the Childrens Hospital Los Angeles Digital Hand Atlas (DHA) as reference. The order in which the atlas is used (G&P followed by DHA or vice versa) for each image was prepared before actual reading begins. Statistical analysis of the results was then performed to determine if a discrepancy exists between the two readings.