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Biomedical subjects

A M Hubbard

Publications and source records attributed to A M Hubbard.

53 records · Page 3Linked to original sources
PubMed1993

Relationship between the ossification center and cartilaginous anlage in the normal hindfoot in children: study with MR imaging.

OBJECTIVE: Although many reports have documented when ossification centers can first be visualized on radiographs, few studies have evaluated the position of the ossification center within its cartilaginous anlage. In the skeletally immature child, the ossification centers of the tarsals are used to evaluate the positions of the tarsals and their interrelationships. It is convenient to assume that tarsal ossification begins in the center of its cartilaginous anlage and proceeds in a radial fashion; however, this may not be the case. Accordingly, we used MR imaging to evaluate the location of the ossification centers of the tarsals within their cartilaginous anlage in the mid and hindfoot in children. MATERIALS AND METHODS: MR studies of 69 feet in 40 children, 3 months to 7 years old (mean, 2.5 years), were reviewed retrospectively. The location of the ossification center within its cartilaginous anlage and the percentage of ossification of the cartilaginous anlagen of the talus, calcaneus, cuboid bone, and navicular bone were determined from coronal and sagittal images. In the talus, the difference between the orientation of the long axis of its ossification center and the long axis of its cartilaginous anlage was measured on coronal and sagittal images. RESULTS: Early talar ossification was centered on the neck of the talus; the proximal aspect of the bone ossified last. The long axis of the talar ossification center and the long axis of its cartilaginous anlage differed in orientation. Early calcaneal ossification was centered on the distal two thirds of the cartilaginous anlage of the calcaneus; the proximal aspect and the area of the subtalar joint ossified last. Early navicular ossification was centered on the central or lateral third of the navicular cartilaginous anlage; the medial aspect ossified last. The ossification center of the cuboid bone was in the middle of the cuboidal cartilaginous anlage. CONCLUSION: Our results show that early ossification in the talus, calcaneus, and navicular bones does not begin in the center of the bones' cartilaginous anlagen. The orientations of the long axis of the talar ossification center and the long mid axis of its cartilaginous anlage are different. Therefore, part of the changes in the alignment of the tarsals seen on radiographs with growth is due to ossification beginning and proceeding eccentrically within the cartilaginous anlage and not to a true change in the alignment of the tarsals. These data provide new information about the normal development of the child's hindfoot and midfoot.

Cartilage↗
PubMed1992

Diagnosis of liver disease in children: value of MR angiography.

We retrospectively studied the clinical use of MR angiography, a gradient-echo technique susceptible to motion, in the preoperative evaluation of the hepatic vasculature in children with liver disease. Twenty imaging examinations were performed in 18 patients 3 months to 10 years old (mean, 2.3 years). Eleven patients had liver tumors and seven had cirrhosis associated with biliary atresia, cystic fibrosis, and short-bowel syndrome. Respiratory motion artifacts were present in most patients, but all MR angiographic studies were technically adequate. Comparing MR angiograms with spin-echo images, we found that vascular visualization was better with MR angiography in 12 cases (60%), equal in five (25%), and worse in three (15%). In 10 of 20 cases, MR angiography provided additional vascular information not present on spin-echo images. MR angiography is a useful adjunct to spin-echo imaging for assessing hepatic vascular anatomy in children with liver disease.

Angiography↗
PubMed1992

Sonography of the elbow in infants and children.

High-resolution real-time sonography of the musculoskeletal system of infants and young children is being used with increasing frequency, in part because of the inability of plain film radiography to visualize unossified cartilage. Real-time sonography now plays an important role in the evaluation of infantile hip dysplasia, as well as in the identification and aspiration of joint effusion. The purpose of this essay is to illustrate clinical situations in which sonography of the elbow is helpful.

Cellulitis↗
PubMed1989

Neurodevelopmental follow-up of infants with birthweight less than 801 grams with intracranial hemorrhage.

The incidence and severity of intracranial hemorrhage (ICH) were determined in a group of surviving infants with birthweights less than 801 g born during the period of 1983 through 1985. Neurodevelopmental status was assessed at 2 and 3 years of age to determine the relationship between neonatal ICH and later outcome in these infants. Forty-four of 77 neonatal survivors (57%) had ICH. Infants with ICH were less mature than those without (25.7 weeks' vs 26.5 weeks' gestation, P less than .05). There were no other perinatal factors that significantly differed between groups. At both 2 and 3 years of age, there were no significant differences between groups of infants with no or mild ICH and those with severe ICH regarding frequency of developmental delay, cerebral palsy, or visual impairment. Persistent ventriculomegaly in infants with ICH was associated with the highest incidence of neurodevelopmental disabilities. For extremely low birthweight infants, the presence and severity of neonatal ICH, in itself, did not adequately predict neurodevelopmental outcome at 2 or 3 years of age. Among infants with ICH, ventriculomegaly persisting to hospital discharge may indicate the greatest risk for neurologic and visual disabilities.

Cerebral Hemorrhage↗
PubMed1983

Radionuclide evaluation in childhood injuries.

Radionuclide techniques serve an important role in evaluating childhood injuries. Frequently, they can be employed as the initial and definitive examination. At times they represent the only modality that will detect specific injuries such as the skeletal system. Familiarity with the advantages and limitations of tracer techniques will insure appropriate management of childhood injuries.

Battered Child Syndrome↗
PubMedDate not supplied

Pediatric interventional radiology: current practice and innovations.

The purpose of this article is to provide an update of pediatric interventional procedures for the interventionalist, and especially for those who treat children infrequently. Most pediatric interventional procedures are modifications of techniques devised for adults, in that some are unique to pediatrics. These are stressed in the presentation.

Arteriovenous Malformations↗
PubMedDate not supplied

Sedation for pediatric patients undergoing CT and MRI.

Adequate sedation remains one of the most important parts of performing high quality cross-sectional imaging in children. This is a noncomparative retrospective analysis of existing sedation protocols used in 1,158 children between the ages of 1 day and 18 years, checking for safety and efficacy. The most commonly used drugs were chloral hydrate (60-120 mg/kg) by mouth for infants less than 18 months and intravenous Nembutal (2-6 mg/kg) for older children. Sedation was successful in 97% of patients.

Administration, Oral↗
PubMedDate not supplied

MRI of focal fibrocartilaginous dysplasia.

Focal fibrocartilaginous dysplasia (FFCD) is an uncommon, benign condition associated with unilateral tibia vara in young children. The clinical, pathologic, plain film, and magnetic resonance imaging (MRI) findings of FFCD were reviewed in two children. MRI findings were virtually identical in both patients and correlated well with the plain film and pathologic findings. We believe that FFCD has a typical MRI appearance. However, FFCD also has characteristic plain film findings, and when these are present, MRI is indicated for only an atypical clinical presentation.

Fibrous Dysplasia, Monostotic↗