PubMed Health⌕ Search

Biomedical subjects

S S Kramer

Publications and source records attributed to S S Kramer.

At least 19 recordsLinked to original sources
PubMed2001

Congenital surfactant protein B deficiency--emphasis on imaging.

BACKGROUND AND OBJECTIVES: Surfactant protein B deficiency has become increasingly recognized as a cause of severe prolonged respiratory distress. Little has been written about the imaging appearance and the role of imaging in diagnosis. MATERIALS AND METHODS: Three newborn infants with severe respiratory distress exhibited prolonged diffuse pulmonary opacification radiographically. RESULTS: Diffuse ground-glass opacity and markedly prominent interlobular septa suggesting alveolar proteinosis were present on early thin-section chest computed tomographic (CT) images. Fibrotic changes with prominent interlobular septal thickening were present on a later CT. Surfactant protein B deficiency was confirmed by alveolar lavage and peripheral blood DNA analysis. CONCLUSION: Thin-section chest CT imaging contributes important information when this diagnosis is considered.

Extracorporeal Membrane Oxygenation↗
PubMed2001

Airway growth after pediatric lung transplantation.

BACKGROUND: Lung transplantation (LT) has been successfully offered to pediatric patients. Very little is known about the growth of the transplanted lung, especially in the infant population. Computerized tomography (CT) scanning is a simple method for studying pediatric patients who have undergone LT. We evaluated the use of CT scans to assess airway growth after pediatric LT, compare airway diameter indexed to somatic growth between LT patients and normals, and compare the growth of pre-anastomotic and post-anastomotic airways indexed to somatic growth in pediatric LT patients. METHODS: We reviewed CT scans on all pediatric patients who underwent primary LT before their fifteenth birthday between January 1995 and September 1998. Uniform measurements of diameter were made in pre-anastomotic (trachea, and proximal right and left bronchi) and post-anastomotic (distal right and left bronchi) sites. These measurements were then correlated with height and compared to previously published normal values. RESULTS: Of the 16 patients who underwent LT during the study period, 11 had at least 2 sequential CT scans (LT age 3 months to 14 years, median 2 years). Thirty-one CT scans were reviewed. Inter-observer variability was within 1 standard deviation (2 mm) in 93% of the measurements and inter-observer reliability was 0.91 by analysis of variance. Tracheal transverse diameter plotted against body height (slope 0.0072, correlation coefficient 0.88) was virtually identical to previously published norms. A similar relationship between airway diameter and height was observed in pre-anastomotic and post-anastomotic segments. CONCLUSION: CT scanning is a reliable method for assessing airway growth in pediatric LT recipients. Tracheal growth in pediatric LT recipients is similar to that of normal children. Post-anastomotic large airways grow similarly to native, pre-anastomotic airways.

Anastomosis, Surgical↗
PubMed2001

Bronchial diseases and lung aeration in children.

Bronchial diseases are common in children, and are usually associated with disturbances of aeration. This article briefly summarizes the embryological development and respiratory physiology pertinent to pediatric bronchial diseases. Current diagnostic imaging tools are discussed, with an emphasis on CT, which can demonstrate bronchial pathology such as bronchial obstruction and bronchiectasis in larger bronchi, as well as indirectly show the peripheral physiologic consequences of bronchial disease, such as alterations in aeration. Computed tomography measurements of lung attenuation may aid in diagnosis in problematic cases. Diseases that affect the pediatric airways at different ages are reviewed. Knowledge of these entities is important for accurate interpretation of imaging studies.

Bronchial Diseases↗
PubMed2001

Methacholine-induced temporal changes in airway geometry and lung density by CT.

PURPOSE: Electron-beam CT (EBCT) was utilized to assess the time course of changes in airways cross-sectional area (CSA) and lung density during methacholine-induced bronchoconstriction. MATERIALS AND METHODS: EBCT scans (200 ms, 3-mm thickness, 2 mm increments) were obtained before (baseline) and 30 s, 2 min, and 4 min after bolus IV injection of methacholine to pigs receiving mechanical ventilation. A total of seven experiments were analyzed using custom-made image analysis software. With each challenge, five different airways and 50 lung regions of interest were studied. RESULTS: The time course of lung density changes paralleled the time course for CSA changes. The maximal response to methacholine, measured in terms of both CSA and lung density changes, occurred 30 s after injection. Lung density changes were unaffected by reconstruction algorithm, normal (standard) or sharp (high resolution). Overall, there was increased air content in the lung during bronchoconstriction. This effect was significantly greater at the dependent lung regions. CONCLUSIONS: EBCT is an effective tool to assess temporal and regional changes in the lung during bronchoconstriction. Measurements of lung density during bronchoconstriction allow for assessment of peripheral changes that are beyond the CT spatial resolution of airways anatomy.

Animals↗
PubMed2000

Current concepts on imaging of thoracic vascular abnormalities.

Pediatric thoracic vascular abnormalities include many anatomic variants and pathologic conditions. Although some vascular variants are inconsequential and are discovered incidentally on imaging studies, several anomalies have profound effects on the airway and pulmonary parenchyma. Imaging plays a key role in evaluating the chest and its vasculature. The chest radiograph is usually the first screening study performed during the course of evaluation for a vascular abnormality. Cross-sectional imaging with CT and magnetic resonance imaging provides precise anatomic information and has in most cases replaced invasive diagnostic angiographic procedures. We describe common thoracic vascular abnormalities that occur in children and the imaging techniques currently used in their evaluation.

Arteriovenous Malformations↗
PubMed1998

Recent advances in pediatric pulmonary imaging.

Beyond basic screening chest radiographs, modern cross-sectional imaging with computed tomography and magnetic resonance imaging demonstrates more detailed anatomic and pathologic information than previously possible. This information is important if it influences decision-making during patient care and management and adds to the understanding of disease processes. In this article we review recent developments in computed tomography and magnetic resonance imaging, advantages and limitations of these techniques in the pediatric chest, and the role of cross-sectional imaging in a series of selected pulmonary topics. In the process, we provide a brief preview of future pediatric pulmonary imaging developments.

Child↗
PubMed1998

Air trapping in children: evaluation with dynamic lung densitometry with spiral CT.

PURPOSE: To evaluate the feasibility of the use of a simple method of dynamic lung densitometry with spiral computed tomography (CT) to differentiate air trapping from compensatory hyperinflation in children. MATERIALS AND METHODS: Eight children (mean age, 4 years 2 months) who had focal areas of radiolucency on chest radiographs underwent spiral CT (5-second acquisition time, fixed table position) during quiet breathing. Data were reconstructed with 0.7-second temporally overlapping scans. Lung attenuation in selected regions of interest was plotted against time. RESULTS: In children with air trapping (n = 5), mean lung attenuation (+/- 1 standard deviation) in hyperlucent regions was -815 HU +/- 52, and mean respiratory excursion was 28 HU +/- 7. In patients with compensatory hyperinflation (n = 4), mean lung attenuation was -664 HU +/- 31, and respiratory excursion was 84 HU +/- 15. The differences were statistically significant (P = .001 for mean attenuation; P < .0005 for respiratory excursion). CONCLUSION: Dynamic spiral CT lung densitometry is a quick, simple method for quantitative confirmation of the presence of air trapping and differentiation from compensatory hyperinflation.

Absorptiometry, Photon↗
PubMed1998

Duodenitis in children: correlation of radiologic findings with endoscopic and pathologic findings.

PURPOSE: To determine the accuracy of barium studies in the diagnosis of duodenitis in children. MATERIALS AND METHODS: Seventy-five children (45 boys and 30 girls; mean age, 9 years) underwent upper gastrointestinal (GI) examinations. Twenty-four of the children had biopsy-proved duodenitis, and 51 were healthy control subjects. Radiologic findings were reviewed by two experienced, blinded observers and correlated with endoscopic and histologic results. Duodenal mucosal-fold thickness was measured on spot radiographs (20% magnification), and the extent of disease was evaluated. RESULTS: Of 15 children with mild duodenitis, 13 had normal radiologic findings and 11 had normal findings at esophagogastroduodenoscopy. Of nine children with severe duodenitis, all had friability or ulceration at endoscopy and mucosal-fold thickening of greater than or equal to 4 mm (> or = 3 mm in one infant aged less than 1 year) at upper GI examination. Mucosal-fold thickening was diffuse in patients with celiac, autoimmune, and adenovirus disease and was proximal in patients with peptic ulcer and Crohn disease. Of 51 control subjects, 50 had normal radiologic results, while 47 had normal endoscopic results. The sensitivity of upper GI examination for mild and severe duodenitis combined was 46% with a specificity of 98%, whereas endoscopy had a sensitivity of 54% and specificity of 92%. CONCLUSION: Mucosal-fold thickening was a specific sign of duodenitis in children and should be investigated. Upper GI examination yielded results similar to those at endoscopy.

Barium Sulfate↗
PubMed1997

Three-dimensional imaging of the pediatric airway.

Accurate imaging of the pediatric tracheobronchial tree is indicated for the evaluation of congenital or acquired abnormalities. Conventional axial computed tomography (CT) is now considered the best imaging modality for evaluation of the trachea and major bronchi, and has almost completely replaced the former gold standard of tracheobronchography. Preliminary results indicate that CT scan performance is further enhanced through the application of spiral technology and two-dimensional (2D) and 3D representation of the tracheobronchial tree. Spiral CT scans with 3D surface rendering offers an opportunity to replace traditional tracheobronchography with a safer, less invasive modality.

Adolescent↗
PubMed1996

Radiographic patterns of intestinal malrotation in children.

Intestinal malrotation is a major diagnostic challenge in children. Sometimes the prognostic significance of the findings from upper gastrointestinal tract examinations is unclear. In a series of 69 surgically proved cases, the authors studied the prevalence and clinical consequences of various radiographic patterns of malrotation and correlated surgical findings with the radiographic location of the duodenum and cecum. Seven patterns of duodenal malrotation were observed. Almost all children in the series had abnormalities of rotation or fixation of both the duodenum and colon, resulting in narrowing of the mesenteric base with potential for midgut volvulus. Of 69 patients, only one (1.4%) had an anatomically normal duodenum, and four (5.8%) had a surgically confirmed normal cecum fixed in the right lower quadrant. In the absence of a corkscrew or Z-shaped duodenum, patterns that usually indicate volvulus or obstructing Ladd bands, colon position had greater prognostic implication, especially when the cecum was situated in the right upper quadrant or left upper quadrant. These latter patterns were associated with the highest prevalence of volvulus.

Adolescent↗
PubMed1996

Intestinal malrotation in children: tutorial on radiographic diagnosis in difficult cases.

PURPOSE: To analyze difficult diagnostic cases of malrotation to identify features crucial to accurate diagnosis. MATERIALS AND METHODS: The authors reviewed the radiographs and records of 81 symptomatic children who underwent surgery with a preoperative diagnosis of malrotation. Eleven had subtle rotational abnormalities (potential false-negative examinations), and 12 had false-positive upper gastrointestinal examinations. RESULTS: Subtle signs of malrotation included unusual redundancy of the duodenum to the right of the spine and location of the duodenojejunal junction (DJJ) medial to the left pedicle. Nevertheless, two children with variations of malrotation had normal upper gastrointestinal examinations. False-positive diagnoses resulted from failure to recognize normal variants: jejunum in the right upper quadrant as the sole finding, DJJ over the left pedicle on the anteroposterior view, "duodenum inversum," and "duodenum mobile." Three children had bowel distention that displaced the DJJ. CONCLUSION: Diagnosis of difficult cases of malrotation may depend on recognition of anatomic subtleties. False-positive diagnoses may be avoided by appreciation of normal duodenal variants.

Adolescent↗
PubMed1995

The pediatric airway.

Accurate diagnosis is important in the evaluation of airway disorders of infants and children. Today, multiple imaging techniques are available to evaluate the pediatric airway. In general, it is best to start with simple and readily available examinations, which may provide a diagnosis in most cases, and progress to more sophisticated studies only in cases where needed.

Bronchi↗
PubMed1995

Bronchiectasis in children.

Bronchiectasis (BR) is a descriptive term for abnormal, irreversibly dilated, and often thick walled bronchi, usually associated with inflammation. Causes are varied but include cystic fibrosis, aspiration, post infectious airway obstruction, immune abnormalities, immotile cilia, posttransplantation states, and congenital bronchial lesions. Although BR is uncommon in children, it causes significant mortality when present. Following a period of presumed decline due to antibiotics and vaccines, BR may increase in prevalence because of AIDS, organ transplantation complications, and changing patterns of childhood immunization. As with adults, high resolution CT (HRCT) is the most useful imaging tool for diagnosis and evaluation of bronchiectasis in children.

Age Factors↗