Gastro-esophageal studies in relationship to respiratory problems.

Gastroesophageal reflux represents a physiological phenomenon in the first year of life. The reflux associated with clinical complications is defined as "gastroesophageal reflux disease" (GERD), that may be esophageal or extra-esophageal, as is for respiratory problems. Nuclear medicine investigations have given an important contribution to the diagnostic assessment and therapeutical management of GERD in children, by means of the following procedures: scintigraphy of the gastroduodenal transit and reflux detection, scintigraphic quantification of gastric emptying, scintigraphy of the esophageal transit, radioisotopic salivagram, scintigraphy of lung perfusion, ventilation and of mucociliary clearance. All of these investigations are among the less irradiating nuclear medicine procedures, therefore particularly adapted to paediatrics. The main clinical advantages of this body of information include: improvements in the management of many asthmatic children, surgical anti-reflux intervention success-rate increase, prompt regional lung alterations detection for preventing stable tissue damage, and many others.

A new experimental procedure for determination of photoelectric efficiency of a NaI(Tl) detector used for nuclear medicine liquid waste monitoring with traceability to a reference standard radionuclide calibrator.

To determine photopeak efficiency for (99m)Tc of the NaI(Tl) detector used for liquid waste monitoring at the Nuclear Medicine Unit of IRCCS Paediatric Hospital Bambino Gesù in Rome, a specific experimental procedure, with traceability to primary standards, was developed. Working with the Italian National Institute for Occupational Prevention and Safety, two different calibration source geometries were employed and the detector response dependence on geometry was investigated. The large percentage difference (almost 40%) between the two efficiency values obtained showed that geometrical effects cannot be neglected.

Renal damage in vesico-ureteric reflux.

OBJECTIVE: To detect the different extent of renal parenchymal involvement in primary vesico-ureteric reflux (VUR), and to evaluate the relationship between VUR grade, patient age and different patterns of parenchymal damage. PATIENTS AND METHODS: This blinded retrospective study included 197 consecutive children (mean age 4.26 years, range 1 month to 13 years) with primary VUR detected by voiding cysto-urethrography (VCUG), 99mTc-dimercaptosuccinic acid (DMSA; 120 MBq/1.73 m2) renal scintigraphy, with scanning for 3 h after intravenous injection. An abnormal DMSA scan was classified into three subtypes: cortical defects as a single scar (SS), multiple cortical scarring (MS) and diffuse reduced uptake with small renal size. Renal absolute uptake (AU), and split-kidney relative uptake were evaluated in refluxing and nonrefluxing renal units, and correlated with parenchymal damage and patient age. Student's t-test and the chi-square test were used for the statistical analysis. RESULTS: In all, 282 refluxing and 112 nonrefluxing units were assessed. Renal damage was detected in 188 of 282 units with VUR (67%) and in 18 of 112 (16%) contralateral nonrefluxing kidneys. The mean AU was 18.7% in kidneys with VUR and 29% in nonrefluxing units (P < 0.001). The mean (SD) AU decreased from lower to higher grades of VUR, i.e. grade 0 VUR (group A), 28.97 (9.71); grade 1-3 (group B), 21.28 (8.33); grade 4-5 (group C), 14.78 (8.02). The differences were statistically significant (A vs B, B vs C, both P < 0.001). Renal damage was differently distributed in the three groups: 69 of 109 kidneys (63%) in group C (MS prevalent), 39 of 173 (22.5%) in group B (SS prevalent) and 17 of 112 (15.2%) in group A. There was no significant difference in the distribution of renal damage subtypes in patients aged < or > 2 years (SS 19.6% vs 17.9%, MS 29.6% vs 30.1%, small size 48.2% vs 46.3%). The VUR was severe (group C) in 65% of patients aged < 2 years and in 46% aged > 2 years (chi-square, P = 0.016). CONCLUSIONS: VUR is commonly associated with renal damage. Age (< or > 2 years) did not significantly influence the kidney lesion subtype. Reduced parenchymal function (AU) progressively decreased with the severity of VUR. Focal MS, reduced size and relative uptake were significantly more common in severe VUR, leading to multifocal lesions and hypo-dysplasia. Renal scarring was present in up to 15% of contralateral nonrefluxing kidneys. Severe VUR behaved differently from lesser VUR in the renal scan parenchymal uptake.

Gastric electric activity assessed by electrogastrography and gastric emptying scintigraphy in adolescents with eating disorders.

BACKGROUND: Patients with eating disorders can refer to a variety of gastrointestinal symptoms, sometimes to justify reduced food intake and vomiting. The authors investigated whether adolescent patients with eating disorders and dyspeptic symptoms have altered gastric electric activity and abnormal gastric emptying as assessed respectively by electrogastrography and scintigraphy. METHODS: Twenty-eight patients (18 with anorexia and 10 with bulimia) and 16 healthy volunteers underwent electrogastrography; 20 of the 28 patients (14 with anorexia and 6 with bulimia) underwent gastric emptying scintigraphy. Electrogastrography with bipolar recording lasted 1 hour, 30 minutes before and after a standard meal. Before gastric emptying scintigraphy, patients fasted overnight; during testing, they ingested a solid meal labeled with technetium-99m sulfur colloid. The ratio of fasting to postprandial electrogastrographic variables was evaluated using the Wilcoxon matched-pair test. The Mann- Whitney test was used to compare absolute values for electrogastrographic data in each group. The Student paired t test was used to compare scintigraphic results expressed as percentage of gastric emptying at 60 minutes and as the gastric emptying time (T(1/2)). RESULTS: Patients with bulimia significantly differed from those with anorexia and control subjects regarding the amount of normal gastric electric activity and bradygastria, and from patients with anorexia only regarding tachygastria. These electrogastrographic variables did not differ significantly between patients with anorexia and control subjects. Gastric emptying time (T(1/2)) was significantly longer in patients with bulimia than in those with anorexia. CONCLUSIONS: Adolescent patients with bulimia who complain of dyspeptic symptoms have documentable abnormalities of gastric electric activity and emptying, whereas their counterparts with anorexia, probably owing to their shorter disease duration, do not.

Is the increase in childhood asthma coming to an end? Findings from three surveys of schoolchildren in Rome, Italy.

Time trends in the prevalence of asthma, family history of asthma and atopy in Roman schoolchildren were assessed. The study population consisted of all children (aged 6-14 yrs) attending two primary schools in Rome, situated in urban areas that differed markedly in socioeconomic conditions and environmental pollution. Three questionnaire-based surveys were conducted in 1974, 1992 and 1998 in 2,259, 1,229 and 1,139 children. The prevalence of asthma in males and females increased significantly during 1974-1992 and remained stable from 1992-1998. In age groups born in the subsequent 4-yr periods it increased almost linearly, for children born from 1962-1965 to 1982-1985 (4.4%-12.5%), and remained remarkably stable in children born after 1985. Because the prevalence of asthma had a steeper trend in males than in females (approximately 0.55% x yr(-1) versus 0.25% x yr(-1)), the male:female asthma ratio increased (1:38 in 1974; 1:84 in 1992 and 1:62 in 1998). No single environmental factor, including area of residence, seemed to influence the prevalence of asthma. Family history of asthma and atopy also increased steadily (0.72% x yr(-1) and 0.30% x yr(-1) respectively) more than doubling during the 24-yr study period. The strong relationship between asthma and a family history of atopy not only persisted but also strengthened over time (23.3% of asthmatic children belonged to families with atopic illnesses in 1974 but 44.2% in 1998). The environmental factors that might explain the almost three-fold rise in childhood asthma between 1974 and 1992 remain unknown but the genetic background of the disease has presumably remained unchanged since the early 1970s. The fact that the prevalence of asthma increased no further during the past 6 yrs suggests that the progressive induction of asthma symptoms in genetically predisposed subjects is a self-limiting process that has probably come to an end in the authors' study area.

Changes over 13 years in skin reactivity to histamine in cohorts of children aged 9-13 years.

BACKGROUND: Several studies report substantial differences in the prevalence of skin test reactivity to allergens in children from adjacent geographic areas; others report an increased prevalence over time. To find out whether these differences depend on variations in skin reactivity to histamine, we determined the time trend of histamine wheal sizes in successive cohorts of unselected children living in the same area (Viterbo, Italy). METHODS: We conducted three epidemiologic surveys, each including children aged 9 and 13 years. The 1983-7 study investigated 170 children (150 were tested twice); the 1992 study, 158 children; and the 1996 study, 208 children. RESULTS: In both age groups, the mean diameter of the wheal induced by histamine skin prick tests (10 mg/ml) increased significantly over time (9-year-olds: 3.25 mm in 1983, 4.68 in 1992, and 5.89 in 1996; 13-year-olds: 3.89 mm in 1987, 5.18 in 1992, and 6.50 in 1996) (P < 0.001 between subsequent studies). The distribution of the wheal diameters for both ages showed a trend to a right shift in the three successive studies (P < 0.001). The dose-response curves for three histamine concentrations (0.2, 1, and 10 mg/ml) had significantly steeper slopes in 1996 than in 1983-7 (P < 0.001). CONCLUSION: The marked time-related increase in the size of the histamine wheals could help to explain the trend toward an increased prevalence of positive allergen skin test reactions reported during the past years. The causes of increased skin reactivity to histamine remain conjectural.

Hepatobiliary scintigraphy in current pediatric practice.

Hepatobiliary scintigraphy is the only non-invasive technique providing real-time assessment of hepatocytes function and bile progression from the liver to the intestine; for this reason it is of great importance in the study of jaundice and many other disorders of the liver and the biliary tract in children. Ultrasonography is the initial method of evaluating the intra- and extrahepatic bile ducts dilatation; the differential diagnosis between biliary atresia and neonatal hepatitis cannot however be done without hepatobiliary scintigraphy. Cystic fibrosis patients also require hepatobiliary scintigraphy; liver and biliary tract disease can really occur independently of the underlying disease severity and the presence of steatorrhea. Hepatobiliary imaging in children who have undergone liver transplantation is of major importance; it can assess vascularity, parenchymal function, biliary drainage, possible presence of a bile leak and obstruction; it has very good sensitivity and specificity for the detection of biliary leak and biliary stricture. Due to these important clinical conditions being studied in pediatrics, both qualitative and quantitative informations (functional indices obtained from radioactivity/time curve analysis) need to be extracted; in addition, SPECT acquisition allows more accurate evaluation of abdominal activity during the excretory phase.

Lung scintigraphy in the assessment of recurrent bronchitis and pneumonia in children.

Recurrent bronchitis and pneumonia in childhood are a significant factor in predisposing adults to chronic respiratory disease. Lung scintigraphy in children with recurrent respiratory problems very frequently shows regional abnormalities, even in the absence of radiological signs: the main problem being the correct clinical use of such a high sensitivity. Structural changes, also at the histological level, are accompanied by functional disturbances that cause lung scan abnormalities to become stable with time and are very likely responsible for persisting disease in adulthood: the above condition needs to be identified by means of follow-up scintigraphies. Moreover, any chronic respiratory condition that has already been diagnosed, like cystic-fibrosis, bronchiectasis, bronchopulmonary malformations, lung fibrosis, should be assessed and followed-up by means of lung scintigraphy. Suspected radiotransparent foreign-body inhalation, radiographical hyperlucencies (compensatory or pathological emphysema?), functional assessment before lung surgery, suspected mucociliary function impairment, suspected interstitial pneumonia, pre-bronchographic or angiographic assessment, all of the above conditions represent important indications to lung scintigraphy in children. Finally, it is wise pointing out that, in order to avoid false positive results towards the diagnosis of structural disease, any easily reversible functional impairment should be removed before the scan, by proper patient preparation: in children this is done by at least aerosol therapy with beta-agonists, local steroids and mucolytics for 1 week-10 days.

Relationship between cotinine levels, household and personal smoking habit and season in 9-14 year old children.

The aim of this study was to determine the relationship of salivary cotinine levels with individual and household smoking habits and with the season in a sample (n = 146) of Italian schoolchildren aged 9-14 yrs. Active smoking and environmental tobacco smoke were measured by means of a confidential standardized interview with each participating child and by a self-reported questionnaire administered to the parents. Saliva samples were obtained twice: during winter from all children and during spring from a randomly selected subgroup. "Active smokers" were significantly more likely to be males and to live with smoking family members. Frequency of detectable cotinine both in "nonsmokers" and "active smokers" was significantly correlated with the number of cigarettes smoked by household members. However, for any level of smoking by parents detectable cotinine was more likely to be found in "active smokers" than in "nonsmokers". In "nonsmokers", the proportion of subjects with detectable cotinine decreased significantly in spring compared to winter, a finding not observed in "active smokers". In conclusion, we have demonstrated that passive smoking produces most effect in winter, and is linked to the amount and style of the parents' smoking, mainly related to smoking in presence of children. Conversely, salivary cotinine detected in spring appears to be derived mainly from active smoking.

Functionally active ganglioneuroma with increased plasma and urinary catecholamines and positive iodine 131-meta-iodobenzylguanidine scintigraphy.

Ganglioneuromas are usually considered not to be functionally active. Studies of their catecholamine excretory pattern and of their imaging by means of the adrenergic tracing agent 131-I-MIBG have been therefore sparse. We report on a case of secretory ganglioneuroma, as demonstrated by the increased urinary excretion of the catecholamine metabolites HVA and VMA, increased plasma dopamine and epinephrine levels, and positive 131-I-MIBG scintigraphy. We must therefore be aware that a functionally active tumor is not necessarily a neuroblastoma, and that the diagnosis should be biopsy proven.

Increased serum IgE and increased prevalence of eosinophilia in 9-year-old children of smoking parents.

We studied the relationship of serum IgE levels and eosinophil counts with passive smoking in 9-year-old, nonselected children from three Italian towns near Rome. Male children of smoking parents had a significantly higher total count and percentage of eosinophils (p = 0.008) and higher IgE levels (p = 0.01) than male children of nonsmoking parents. Prevalence of eosinophilia (defined as greater than or equal to 4% of total white blood cell count) was significantly correlated with the number of cigarettes smoked by parents among boys (p = 0.003) but not among girls (p = 0.20). There was a significant trend (p = 0.008) for prevalence of eosinophilia to increase with increasing levels of serum IgE. For any given level of serum IgE, the frequency of eosinophilia was higher among children of smoking parents than among children of nonsmoking parents. When parental smoking was studied in a multivariable analysis and after controlling for the other variable, it was still significantly associated with eosinophilia in the children of these smoking parents but not with serum IgE levels. We conclude that parental smoking is associated with a significant enhancement of the expression of the most important markers of allergic sensitization in the children of smoking parents. This is particularly evident for boys and may explain, at least in part, the increased frequency of respiratory symptoms in children of smoking parents.

A radiopharmaceuticals schedule for imaging in paediatrics. Paediatric Task Group European Association Nuclear Medicine.

There is no standard schedule for the amounts of radiopharmaceutical administered to children at present. Various alternative methods are currently in practice, all with some support from the literature. Optimization of the amount of radiopharmaceutical to be administered is discussed in relation to the radiation burden of such an examination. The Paediatric Task Group of the European Association of Nuclear Medicine has investigated the current situation and now suggests a method for standardization of administered amounts of radiopharmaceutical in paediatrics. The fraction of the adult amount of radiopharmaceutical to be administered should be calculated from the child's body weight according to the accompanying table. In small infants, the minimum amount of a radiopharmaceutical is discussed and suggested amounts to be administered are presented.

[Esophageal atresia associated with a subglottal stenosis. Apropos of a case]. / Atrésie de l'oesophage associée à une sténose sous-glottique. A propos d'un cas.

The authors report a case of a 3 kg newborn with oesophageal atresia and congenital subglottic stenosis. The literature is reviewed and the management of our case reported. As in many cases the subglottic stenosis outgrows within a year of age, though tracheostomy is not justified even if general anesthesia is needed in case of major surgery.

Regional lung function in bilateral diaphragmatic paralysis.

1. The distribution of regional function in the lungs of six patient with bilateral diaphragmatic paralysis was investigated by continuous inhalation and infusion of the radioactive gases 81mKr and 85mKr during tidal breathing. 2. In the supine and right lateral decubitus postures the vertical distribution of ventilation per unit alveolar volume was less in the dependent zones, the reverse of that found in normal subjects. In the upright posture ventilation was slightly decreased at the lung base. Perfusion per unit alveolar volume was more uniformly distributed than normally in the upright posture, and decreased from superior to inferior in the supine posture. In the lateral decubitus posture, perfusion of the lower lung was greater than that of the upper. Ventilation/perfusion ratios were more uniformly distributed in the patients than in normal subjects, except in the right lateral decubitus posture. 3. Alterations in the distribution of ventilation may be explained in terms of the altered mechanical interaction of chest wall, mediastinal and abdominal contents, with selective use of intercostal and accessory muscles. The effects on the distribution of blood flow are probably related to the low end-expiratory lung volume.

Quantitative approach to the study of regional lung function in children using krypton 81m.

Krypton 81m has many advantages for paediatric lung imaging, although the proper interpretation of ventilation and perfusion lung scans requires the quantitative analysis of the steady state images and clearance curves. Both the theory and practice are described and illustrated by means of 11 paediatric cases aged from 18 days to 14 years. It was possible to calculate the regional distributions of ventilation and perfusion and the normalized ventilation-perfusion (V/Q) ratios. Of greater functional significance was the detection of differences between the clearance rates of inhaled and infused 81Krm within single regions, since such differences reflected the dispersion of V/Q ratios amongst lung units within individual regions.