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Biomedical subjects

G S Bisset

Publications and source records attributed to G S Bisset.

At least 19 recordsLinked to original sources
PubMed2001

Reliability of CXR for the diagnosis of bronchopulmonary dysplasia.

BACKGROUND: Bronchopulmonary dysplasia (BPD) continues to be prevalent, despite new treatment, in part because of increased survival in less mature infants. Investigations of new treatments have been hampered by a lack of universally accepted diagnostic criteria. Radiographic scoring systems have been developed to provide objective assessment of lung injury and risk for chronic lung disease. OBJECTIVE: We sought to test the reliability of a recently reported system using chest radiography as the main tool for diagnosis of BPD. MATERIALS AND METHODS: One hundred chest radiographs, half demonstrating BPD and the other half without BPD, were analyzed by pediatric radiologists and by a neonatologist, using the Weinstein score (1-6, depending on increasing radiographic severity). The reliability of this scoring system was tested by kappa (k) statistics. RESULTS: Reliability at the lowest threshold (dividing score 1 from score > or = 2) was unacceptably low in this population. Reliability increased with inclusion of higher BPD scores in the comparison groups: 1-3 versus 4-6. CONCLUSION: Using the chest radiograph for the prediction of BPD is not reliable between different observers except at the two extremes of the disease.

Bronchopulmonary Dysplasia↗
PubMed2000

Marked acute tissue swelling following percutaneous sclerosis of low-flow vascular malformations: a predictor of both prolonged recovery and therapeutic effect.

PURPOSE: To evaluate the significance of marked, acute swelling in patients after percutaneous sclerosis of low-flow vascular malformations, as a predictor of both prolonged recovery and likelihood of therapeutic effect. MATERIALS AND METHODS: In 22 patients who underwent percutaneous ethanol sclerosis of low-flow vascular malformations, we compared the incidence of prolonged recovery and lasting therapeutic effect between those patients with and without marked soft-tissue swelling following the procedure. RESULTS: Five patients exhibited marked swelling after sclerosis. Four of these five had causes of prolonged recovery. These four recovered and all five eventually had marked therapeutic effect. Seventeen patients did not meet criteria for severe swelling. Only one of these patients had prolonged recovery. Eighteen of the 22 total patients had therapeutic effect. All 4 of the 22 total patients who had no therapeutic effect were in the group without marked swelling. CONCLUSIONS: Marked soft-tissue swelling, which occurs after percutaneous sclerosis of vascular malformations, is both a predictor of prolonged recovery and high likelihood of therapeutic effect.

Acute Disease↗
PubMed2000

Differentiating normal from abnormal inferior thoracic paravertebral soft tissues on chest radiography in children.

OBJECTIVE: The purposes of this investigation were to define the normal appearances, define factors that have the potential to influence appearance, and establish defined criteria to differentiate normal from abnormal appearances of posteroinferior paravertebral soft tissues on chest radiography in children. SUBJECTS AND METHODS: Paravertebral soft tissues were evaluated on frontal chest radiographs in 23 children with documented abnormalities and 275 children without abnormalities in the region. The frequency of visualization, course, width, and factors (patient positioning, age, and sex) potentially influencing the appearance of paravertebral soft tissues were determined. Inferolateral course and width greater than that of the adjacent pedicle were evaluated as criteria for abnormality. RESULTS: Only 28% of the children without abnormalities had paravertebral soft tissues visualized, and the frequency of visualization directly increased with age (p = 0.001). For identification of abnormal cases on the left side, width greater than the adjacent pedicle had a sensitivity of 100% and a specificity of 98%, and inferolateral course had a sensitivity of 86% and a specificity of 95%. Visualization on the right side (n = 5) was always abnormal. Six normal cases had a width greater than that of the adjacent pedicle on the left side on initial radiographs obtained with supine positioning and met normal criteria on repeated radiographs with upright positioning. CONCLUSION: Width greater than the adjacent pedicle is the best radiographic criterion for differentiation of abnormal from normal left-sided paravertebral soft tissues, particularly on radiographs obtained with upright positioning. Identifiable right-sided paravertebral soft tissue is always abnormal. These criteria are useful aids in determining the need for additional imaging, such as CT.

Adolescent↗
PubMed1999

Imaging of pediatric mesenteric abnormalities.

The relative paucity of mesenteric fat seen in the pediatric population can make detection and localization of processes in the mesentery difficult. This pictorial essay reviews pediatric mesenteric disorders and presents criteria that help localize processes to the mesentery. Disorders are categorized by specific patterns of involvement, which can readily be identified by imaging: developmental abnormalities of mesenteric rotation, diffuse mesenteric processes, focal mesenteric masses, and multifocal mesenteric masses.

Adolescent↗
PubMed1999

Chronic avulsive injuries of childhood.

Children and adolescents are prone to avulsive injuries related to a combination of their propensity for great strength, ability to sustain extreme levels of activity, and immature growing apophyses. Appropriate interpretation of imaging studies showing chronic avulsive injuries is essential so that the irregularity and periostitis that can be associated with chronic avulsions is not misinterpreted as probable malignancy. This article reviews the chronic avulsive injuries of childhood.

Athletic Injuries↗
PubMed1999

Heterogeneous splenic enhancement patterns on spiral CT images in children: minimizing misinterpretation.

PURPOSE: To (a) determine the appearances and timing of heterogeneous splenic enhancement at spiral computed tomography (CT) and (b) identify variables influencing heterogeneous splenic enhancement. MATERIALS AND METHODS: Sequential isolevel (24-mAs) CT images of the spleen obtained at 6-second intervals after initiation of contrast material injection in 112 children (mean age, 4.5 years) were reviewed. Heterogeneity characteristics assessed included type, onset, maximum, and resolution. Relationship to variables (injection rate, age, splenomegaly) was assessed with the Fisher exact test. RESULTS: Eighty-one of the 112 patients (72%) had transient heterogeneity: archiform (45 patients), diffuse (25 patients), and focal (11 patients). Mean times were as follows: initial visualization after onset of contrast material injection, 19.2 seconds; maximum heterogeneity, 27.3 seconds; and resolution, 47.4 seconds. Statistically significant relationships were seen between frequency of heterogeneity and injection rate (> or = 1 mL/sec, 82%; < 1 mL/sec, 50% [P = .001]), age (> 1 year, 76%; < or = 1 year, 46% [P = .04]), and splenomegaly (present, 20%; absent, 77% [P = .048]). CONCLUSION: Heterogeneous splenic contrast enhancement is common, has several patterns of appearance, and is predictably encountered during the 70 seconds after the initiation of contrast material injection. Injection rate, age, and presence of splenic disease influence the frequency with which these artifacts are encountered.

Artifacts↗
PubMed1999

Subcutaneous granuloma annulare: MR imaging features in six children and literature review.

PURPOSE: To describe the magnetic resonance (MR) imaging findings of subcutaneous granuloma annulare (SGA), a rare mass of early childhood. MATERIALS AND METHODS: MR imaging studies and clinical records in six children aged 2 1/2-4 years in whom SGA was diagnosed between 1993 and 1997 were retrospectively reviewed. All MR imaging examinations included T1-weighted and fast spin-echo T2-weighted sequences. Three children received intravenous contrast material. The diagnosis was established by using excisional biopsy results, with confirmation by means of characteristic features in mucin-stained specimens. RESULTS: All children presented with a nontender, nonmobile mass. The lesion in all six children was confined to the pretibial (n = 5) or prepatellar (n = 1) soft tissues. MR imaging characteristics were uniform. Masses were subcutaneous in location and had ill-defined margins. On T1-weighted images, the lesion was isointense or slightly hyperintense to muscle. On T2-weighted images, the signal intensity was more heterogeneous, but the lesion was predominantly hyperintense. In three children who received contrast material, the lesion enhanced nearly homogeneously. CONCLUSION: Although SGA can often be diagnosed on the basis of clinical characteristics, MR imaging may be requested by practitioners unfamiliar with the lesion. In these cases, with recognition of typical MR imaging features, a limited biopsy and specific histologic preparation that includes mucin staining can be recommended.

Biopsy↗
PubMed1999

Chronic avulsive injury of the deltoid insertion in adolescents: imaging findings in three cases.

The clinical and imaging (magnetic resonance [MR] imaging, radiography, and bone scintigraphy) findings in three adolescent boys with chronic avulsive injury at the deltoid insertion are presented. MR imaging enabled the exclusion of findings suggestive of malignancy and the localization of abnormalities to the deltoid insertion site. Findings included cortical thickening and irregularity of the deltoid tubercle, with or without adjacent soft-tissue edema.

Adolescent↗
PubMed1999

Anterior chest wall: frequency of anatomic variations in children.

PURPOSE: To evaluate the frequency of anterior chest wall variations in children. MATERIALS AND METHODS: The computed tomographic (CT) images of 200 consecutive infants and children (114 boys and 86 girls; mean age, 10.5 years; age range, 3 months to 19 years) who underwent chest CT during a 20-month period were evaluated for chest wall variations. Children who had undergone chest wall surgery or were suspected of having a chest wall abnormality were excluded. The frequency of chest wall anomalies was compared with age and sex (Fisher exact test). RESULTS: The CT scans of 65 children (33%) depicted one or more variations in the anterior chest wall: titled sternum (n = 29), prominent convexity of anterior rib or costal cartilage (n = 19), prominent asymmetric costal cartilage (n = 20), well-defined paracostal subcutaneous nodule (n = 4), mild pectus excavatum (n = 4), or mild pectus carinatum (n = 4). The frequency of these findings did not vary significantly with age (P = .96) or sex (P = .36). CONCLUSION: Variations in the anterior chest wall are common, occurring in one-third of children, and should be considered normal. These asymptomatic variations should not be considered alarming when palpated at physical examination.

Adolescent↗
PubMed1999

Gastric retention of zinc-based pennies: radiographic appearance and hazards.

PURPOSE: To determine the radiographic appearance and features of corrosion in U.S. coins exposed to gastric acid. MATERIALS AND METHODS: Six U.S. copper-based pre-1982 pennies, 12 zinc-based post-1982 pennies, a quarter, a nickel, and a dime were exposed to postprandial concentrations of gastric acid (0.15N HCl) for 7 days, and radiographs were obtained daily. Half the zinc-based coins were scraped to disrupt their copper coating. Coins were weighed at the start and completion of the study. RESULTS: Post-1982 zinc-based pennies developed radiolucent corrosive changes within 24 hours. Erosions on the coins became more apparent over time. Frank holes were present on day 2. The weights of these coins decreased 5%-8% during the study. Pre-1982 copper pennies and "silver-colored" coins showed no change on radiographs over 7 days. CONCLUSION: Unexpected radiolucent corrosions may develop in post-1982 zinc alloy pennies when retained in the stomach. Coins have long been considered innocuous foreign bodies in the gastrointestinal tracts of children. However, because of the potential for ulceration and zinc-related morbidity, closer clinical and radiographic observation is warranted. Coins with scalloped edges or holes should be endoscopically removed, as they have likely been retained longer than 1 or 2 days.

Child, Preschool↗
PubMed1999

The appearance and significance of extrapleural fluid after esophageal atresia repair.

OBJECTIVE: The objective is to describe the appearance and evaluate the significance of postoperative extrapleural fluid collections in neonates who have undergone esophageal atresia repair in which an extrapleural surgical approach was used. CONCLUSION: Extrapleural effusion in a neonate who has undergone repair of esophageal atresia by an extrapleural approach is associated with a high incidence of anastomotic leakage. Such patients may also be at increased risk for developing a delayed esophageal stricture. On chest radiography, these extrapleural effusions look like fluid in the pleural space.

Diagnosis, Differential↗
PubMed1999

Optimizing contrast-enhanced abdominal CT in infants and children using bolus tracking.

OBJECTIVE: Manual administration of IV contrast material results in unpredictable injection rates. Our purpose was to determine the effect of bolus tracking on overall abdominal helical CT scan quality, particularly on hepatic enhancement, in children with manually administered contrast media. MATERIALS AND METHODS: We compared 33 abdominal helical CT scans of 29 children in whom bolus tracking was used with 22 CT scans of a control group of 21 children in whom bolus tracking was not used. All contrast material was administered by manual injection. Qualitative assessment was made of organ and vessel enhancement and overall scan appearance. Quantitative assessment using region-of-interest cursors was performed at three anatomic levels, and the results for the two groups of children were compared. RESULTS: Qualitative comparison of enhancement parameters between the bolus tracking group (number given first) and the control group (number given second) yielded the following: splenic artifact in 9% versus 23% (p = .24); inferior vena cava flow artifact in 3% versus 27% (p = .01); scanning during the nephrographic phase in 89% versus 59% (p = .02); and good quality grade in 79% versus 64% (p = .23). Significantly greater hepatic enhancement (as measured in mean Hounsfield units) was achieved in the bolus tracking group than in the control group at the superior (48.5 versus 28.6; p < .001), middle (47.9 versus 32.3; p < .001), and inferior (48.2 versus 36.5; p = .01) levels. Hepatic enhancement increased significantly from the superior to the inferior level in the control group (p < .02), whereas enhancement was homogeneous in the bolus tracking group (p > .50). CONCLUSION: Bolus tracking provides improved contrast enhancement, including significantly greater hepatic enhancement, during abdominal helical CT in children in whom the rate of injection of contrast material is unpredictable.

Child↗
PubMed1998

Necrotizing myofasciitis: an atypical cause of "acute abdomen" in an immunocompromised child.

We report the case of an immunocompromised 15-year-old boy who presented with symptoms mimicking an "acute abdomen" related to necrotizing myofasciitis of the anterior abdominal wall. CT demonstrated the abdominal wall process as the cause of the patient's symptoms and sonographically guided aspiration confirmed the diagnosis. Despite prompt diagnosis and aggressive surgical debridement, the infection continued to progress and the patient died within 24 h of presentation.

Abdomen, Acute↗
PubMed1998

Overview of vascular disease.

Vascular disease in the pediatric population is a poorly understood process which is often underestimated in its incidence. The common beginnings of such ubiquitous diseases as atherosclerosis manifest themselves at a cellular level shortly after birth. Other common systemic disorders, including congestive heart failure and sepsis, are also intricately associated with dysfunctional vasculature. Progress in the understanding of normal and pathophysiologic processes within the vascular system begins with the "control center"--the endothelial cell. The purpose of this review is to consolidate a body of knowledge on the processes that occur at the cellular level within the blood vessel wall, and to simplify the understanding of how imbalances in these physiologic parameters result in vascular disease.

Child↗
PubMed1998

Tarsal coalition: a blinded comparison of MRI and CT.

OBJECTIVE: To determine how well MRI can detect tarsal coalition compared with CT, the current imaging standard. MATERIALS AND METHODS: Coronal and axial CT and MRI were performed within 3 weeks of each other on 40 feet in 20 consecutive patients referred with symptoms of possible tarsal coalition. Scans were read independently in blinded fashion by different imagers. Coalitions were either complete (osseous) or incomplete (non-osseous). Results were compared with available surgical data and clinical follow-up. RESULTS: Both modalities prospectively identified 15 coalitions (9 patients) and each missed 1 calcaneonavicular coalition. Twenty-three of the remaining 24 feet were negative for coalition on both CT and MRI. An atypical incomplete talocalcaneal coalition seen on CT was not identified prospectively on MRI. CONCLUSION: MRI is very good for detecting tarsal coalition and has a high rate of agreement with CT, the imaging "gold standard." When clinical suspicion for coalition is high, CT remains a more cost-effective diagnostic modality. If other causes for ankle pain are also entertained, MRI can be performed and provide nearly equivalent diagnostic accuracy for detecting tarsal coalition.

Adolescent↗