Plasma neutrophil lipocalin, elastase-alpha1-antitrypsin complex and neutrophil protease 4 in preterm infants with respiratory distress syndrome.

Respiratory distress syndrome (RDS) and chronic lung disease of prematurity (CLD) are associated with inflammation of the airways and interstitial tissue of the lung. It is hypothesized that RDS severity and the risk of developing CLD may be correlated with neutrophil gelatinase-associated lipocalin (NGAL), a marker of leucocyte activity, human elastase-alpha1-antitrypsin complex (HEAT) or free and complexed neutrophil protease 4 (NP4), markers of proteolytic enzyme secretion from granulocytes. Thirty-three preterm infants with RDS were enrolled in the study and plasma sampled between 3 and 14 days of life. NGAL, HEAT and NP4 concentrations varied widely in infants with RDS. Significant correlations between subsequent development of CLD and plasma concentrations of HEAT and NP4, respectively, were found on days 3-4 of life, p=0.006 and p=0.02, respectively.

Tracheobronchial aspirate fluid neutrophil lipocalin, elastase- and neutrophil protease-4-alpha1-antitrypsin complexes, protease inhibitors and free proteolytic activity in respiratory distress syndrome.

UNLABELLED: This study aimed to determine whether the protease/protease inhibitor balance and neutrophil activity is of pathophysiological importance in the severity and resolution of respiratory distress syndrome (RDS) and the eventual development of neonatal chronic lung disease (CLD). Ventilated preterm infants with RDS (n = 43) were studied during their first week of life. Tracheobronchial aspirate fluid (TAF) concentrations of neutrophil lipocalin, the elastase- and neutrophil protease-4 (NP4) complex concentrations, and alpha1-antitrypsin (alpha1AT), antichymotrypsin (ACT) and secretory leucocyte protease inhibitor (SLPI) levels were analysed. Free proteolytic and elastolytic activities were also determined. CLD correlated with low alpha1AT (p = 0.02) and ACT (p = 0.02) levels at 3-4 d of age and low SLPI (p = 0.03) at 7-8 d of age. No correlations were found between CLD or severity of RDS (as judged from radiological examination) and neutrophil lipocalin, elastase- and NP4-alpha1AT complexes during the first week of life, with one exception: RDS X-ray severity and the elastase-alpha1AT complex concentration were correlated at 3-4d of age (p = 0.02). Free proteolytic activity occurred in the TAF of 7/30 infants tested on day 3-4 and free elastolytic activity in 1 patient. During the rest of the first week of life no free elastolytic or proteolytic activities were observed. Caesarean section was correlated with low levels of SLPI on day 3-4 (p = 0.01), NP4 (p = 0.03) and ACT (p = 0.05) on day 5-6. Gestational age was positively correlated with protease inhibitors and their complexes at 3-4 d of age. CONCLUSION: Free proteolytic or elastolytic activity in the TAF of RDS infants in the first week of life occurred by way of exception. Elastase-/NP4-alpha1AT complex or neutrophil lipocalin levels were not correlated with the development of CLD. The correlation between CLD and low alpha1AT or ACT at 3-4 d and SLPI at 7-8 d of age may be due to either immaturity or complex formation. The severity of RDS as judged from radiological examination was correlated with elastase-alpha1AT complex on day 3-4. The main hypothesis, that TAF protease/protease inhibitor levels or imbalance and leucocyte activity are important factors indicating a high risk of severe RDS and subsequent CLD development, was principally not confirmed.

Coil embolization of a neonatal pulmonary arteriovenous malformation.

Pulmonary arteriovenous malformation (PAVM), as a part of Osler-Weber-Rendu Syndrome, in the neonate, is a rare hereditary vascular malformation. Large intrapulmonary right-to-left shunting, causing hypoxaemia and cyanosis, can be a life-threatening condition. Repeated transcatheter coil embolization procedures proved to be a favorable strategy to improve systemic arterial oxygen saturation, with a good outcome in a newborn child. While the radiation dose was high, the use of this amount of radiation was felt to be justified and its effects considered tolerable in the treatment of this patient's serious malformation.

Contrast-enhanced thoracic 3D-MR angiography in infants and children.

PURPOSE: To optimise breath-hold contrast-enhanced MR angiography (MRA) in infants and children with suspected congenital heart or thoracic vessel malformation. MATERIAL AND METHODS: Thirty-nine children (median age 1 year) were examined, using five different ultrafast MRA sequences with a TR between 3.2 and 5.0 ms and the contrast agent meglumine gadoterate. A test injection was used to determine contrast travel time. Different parameters for contrast injection were evaluated. Signal-to-noise ratio (SNR) measurements were performed and image quality and injection timing were evaluated. RESULTS: MRA was successful in all patients and image quality was considered very good in 52%. Adequate SNR was achieved with no significant differences between the MR sequences. SNR decreased only 25-30% between subsequent scans. The mean contrast dose was 0.23 mmol/kg. The mean scan time was 12.5 +/- 3.8 s; the shorter scan times made dynamic examinations possible with high temporal resolution. Highest spatial resolution was obtained with TR 4.6/5.0 sequences. CONCLUSION: A contrast dose of 0.2 mmol/kg b.w. is recommended with an injection rate of 0.5 to 1.2 ml/s, depending on patient size and scan time. The scan delay time should equal the contrast travel time for optimal vessel enhancement. In the future, contrast-enhanced MRA may be a potential alternative to angiocardiography in infants and children.

Pre-operative evaluation with MR in tetralogy of fallot and pulmonary atresia with ventricular septal defect.

PURPOSE: To assess whether MR imaging could replace angiography in preoperative evaluation of patients with tetralogy of Fallot and pulmonary atresia with ventricular septal defect (VSD), especially since the surgical correction was done earlier than was previously the rule. MATERIAL AND METHODS: Fourteen patients with tetralogy of Fallot (n = 10) or pulmonary atresia with VSD (n = 4), mean age 7.5 +/- 4.4 months, were evaluated with angiocardiography and MR before definitive surgical correction. RESULTS: There was good diagnostic agreement between the two modalities when evaluating right ventricular outflow obstruction; 86% for valvular and 93% for supravalvular stenosis, but the agreement was somewhat lower for the subvalvular obstruction (57%). Surgery findings, however, were in favour of MR in 5 patients concerning the subvalvular right ventricular outflow tract obstruction. MR images identified all stenoses in the right and left pulmonary arteries, but overlooked one stenosis in the main pulmonary artery. MR could evaluate patency in all palliative shunts. CONCLUSION: Even in this young age group, MR imaging offers a good alternative to angiocardiography for the pre-operative evaluation of the right ventricular outflow tract, the main pulmonary artery and the proximal right and left pulmonary arteries, before definitive surgical correction of tetralogy of Fallot and pulmonary atresia with VSD.

[Digital imaging system are rapidly introduced in Swedish departments of radiography. This calls for new strategic planning]. / Digitala bildsystem införs nu snabbt på röntgenavdelningarna i Sverige. Detta ställer nya krav på beredskapsplaneringen.

Diagnostic radiology in Sweden is changing rapidly to digital (filmless) technique. The advantages are more rapid delivery of radiologic service, better working conditions and less negative effects on the environment. Teleradiology is also facilitated. The Swedish Board of Health and Welfare has investigated the speed with which this change is taking place. In 1998, 26 of the 118 departments of diagnostic radiology had already turned digital; it is estimated that in the near future at least five departments will become fully digital each year. For planning purposes, less emphasis should be put on the supply of radiographic film, and more on telecommunications, computer hardware and digital storage.

Percutaneous nephrostomy in infants and children.

RATIONALE AND OBJECTIVES: The purpose of this study was to review the authors' experience with percutaneous nephrostomy during an 11-year period, paying special attention to indications and outcomes. MATERIAL AND METHODS: The records of 71 percutaneous nephrostomy procedures performed on 59 children at the authors' institution from January 1987 through December 1997 were retrospectively reviewed. In these children, ultrasonography was used for puncture and fluoroscopy for catheter insertion. Local anesthesia with sedation was used and later replaced by general anesthesia. Loop-end catheters were employed. The smallest patient weighed 1,200 g, and the mean patient age was 3.4 years. RESULTS: The mean duration of drainage was 60 days, and the longest time was 11 months. Indications were mainly obstructions, with congenital obstruction (n = 28) and postoperative obstruction (n = 26) being the most common. Obstructive pyelitis, malignancy, stone, renal cystic disease, trauma, and neurogenic bladder disturbance were also indications. No complications such as loss of the kidney, serious infection, or hemorrhage of clinical importance were observed. Obstruction was successfully relieved in all patients, but 12 kidneys and five hemikidneys did not recover function and were eventually removed. CONCLUSION: The percutaneous nephrostomy procedure is a safe technique that can be used successfully for short- and longterm drainage in all children, even in small infants and those with solitary kidneys, and is a valuable adjunct to surgery.

Left-to-right cardiac shunts: comparison of measurements obtained with MR velocity mapping and with radionuclide angiography.

PURPOSE: To investigate the agreement between two noninvasive methods, magnetic resonance (MR) velocity mapping and first-pass radionuclide angiography, to quantify the pulmonary-to-systemic blood flow ratio (QP/QS) in adults, adolescents, and children with left-to-right cardiac shunts. MATERIALS AND METHODS: The accuracy and precision of MR velocity mapping were studied in 12 control subjects (six men, six women) and in a phantom. MR velocity mapping and radionuclide angiography were performed on the same day in 24 patients (16 adults, two adolescents, six children; five male patients, 19 female patients). RESULTS: The mean error in QP/QS at MR velocity mapping in phantom experiments was -1% +/- 1 (mean +/- SD). In control subjects, QP/QS at MR velocity mapping was 1.03 +/- 0.03, and the cardiac index was 3.1 L/min/m2 +/- 0.2 and 3.2 L/min/m2 +/- 0.3 for women and men, respectively. In patients, QP/QS at radionuclide angiography was 14% +/- 13, higher than at MR velocity mapping. Interobserver variability was four times higher for radionuclide angiography compared with MR velocity mapping, 0% + 16 versus 0% +/- 4 (n = 12). The difference between repeated MR flow measurements in the same vessel was -1% +/- 5 (n = 36). CONCLUSION: The data suggest that MR velocity mapping is accurate and precise for measurements of shunt size over the whole range of possible QP/QS values.

Intralobar bronchopulmonary sequestration in the newborn--a congenital malformation.

BACKGROUND: Intralobar sequestration (ILS) has been suggested to be an acquired lesion. However, we have observed several young infants who had ILS. OBJECTIVES: Since this fact seems to indicate a congenital origin, we reviewed our experience. MATERIAL AND METHODS: A retrospective review of bronchopulmonary sequestration from the Departments of Radiology and Pathology in Lund between 1964 and 1997. RESULTS: We identified seven infants or young children with a diagnosis of intralobar sequestration. In each patient, the ILS was present before recurrent infection developed. Five had chest X-rays as neonates, one at 3 months and one at 11 months of age. All but one showed an abnormality on their first chest X-ray, consistent with sequestration. Six of the ILS were verified at angiography; all seven were surgically removed. Two of the children with ILS also had congenital cystic adenomatoid malformation (CCAM). Three children had both ILS and scimitar syndrome. CONCLUSIONS: The fact that ILS was present in seven newborn and young infants indicates that this lesion is, at least in some patients, a congenital malformation.

Functional evaluation of extracardiac ventriculopulmonary conduits and of the right ventricle with magnetic resonance imaging and velocity mapping.

Extracardiac ventriculopulmonary conduits tend to deteriorate over time, developing both obstruction and regurgitation. In this prospective study, magnetic resonance imaging (MRI) was compared with Doppler echocardiography to determine whether MRI improves the noninvasive evaluation of conduit patients. Twenty-five patients (median age 10 years, range 2.5 to 32) were investigated 27 times with Doppler echocardiography and an MRI protocol with spin echo sequences for morphology, velocity mapping, and multislice gradient echo technique for right ventricular volume measuring. Cardiac catheterization data were available in 6 patients. Echocardiography could assess the morphology of the conduits in 6 patients, whereas MRI demonstrated all conduits efficiently. Doppler echocardiography could evaluate the occurrence of regurgitation in 18 patients and could quantify peak velocity in 20 of the patients. A technically adequate MRI velocity mapping was obtained in 25 patients. There was good agreement between MRI and Doppler echocardiography in establishing or not establishing regurgitation, but Doppler echocardiography was less reliable in evaluating the degree of regurgitation. The correlation between peak velocity determined with Doppler and magnetic resonance imaging was r = 0.63 [corrected]. Correlations between catheterization pressure gradients and noninvasive techniques were r = 0.97 for magnetic resonance imaging [corrected] versus catheterization, and r = 0.86 [corrected] for Doppler versus catheterization. MRI can provide complete information on the morphology and function of extracardiac ventriculopulmonary conduits, as well as of the right ventricle. If the results of MRI and echocardiography with Doppler are in agreement, heart catheterization and angiography can be avoided, even in patients considered for conduit replacement.

Spatial resolution requirements in digital radiography of scaphoid fractures. An ROC analysis.

PURPOSE: To investigate the spatial resolution requirements in digital radiography of scaphoid fractures. MATERIAL AND METHODS: Included in the study were 60 scaphoid radiographs with and 60 without fractures of the scaphoid bone. The film-screen images were digitized using pixel sizes of 115, 170, and 340 microns along with 170 microns with a 10:1 wavelet compression. The digital images were displayed on a 1280 x 1024 x 8 bits monitor, and 5 observers evaluated the images in 5 randomized sessions. The results for each pixel size were then compared to the film-screen images by ROC analysis. RESULTS: The mean area under the ROC curves was larger for the film-screen images than for the digital images at all resolutions. However, this difference was not significant when the areas under the ROC curves for the film-screen images were compared to the digital images of 115, 170, and 170 microns with 10:1 compression. There was a significant difference for the 340-microns pixel size in favour of the film-screen images. The mean ROC curves for the digital images were very similar for the 115 and 170 microns pixel sizes, although slightly better for 115 microns. At 170 microns, the compression seemed to have a relatively small negative effect on the diagnostic performance; the deterioration was greater when the pixel size was increased to 340 microns. There was no obvious correlation between diagnostic performance and the experience of the observers in using work-stations. CONCLUSIONS: The pixel size of 170 microns is adequate for the detection of subtle fractures, even after wavelet compression by a ratio of 10:1.

Complex congenital heart malformation evaluated with MR imaging at 0.3 T.

The aim of this study was to evaluate the efficiency of MR imaging at 0.3 T as the single modality in diagnosing complex congenital heart disease (CHD). Films from 45 cases were reviewed in two stages by four specialists and one fellow in pediatric radiology, who were unfamiliar with the patients. First a general review of CHD diagnosis was made, then a detailed study of anomalous venous return was performed. Regarding the general diagnosis of cardiovascular anomalies the results were good, with sensitivity of 80%, specificity of 96%, a positive predictive value of 88%, a negative predictive value of 93% and accuracy of 92%. As expected, the less experienced reviewer had somewhat lower figures. As for detailed evaluation of the anomalous veins, the diagnostic results were again good (sensitivity 85%), although less so when also the connection sites of the anomalous veins were considered (sensitivity 79%). The specificity of the findings was high at 97%. MR imaging at 0.3 T is valuable in the diagnosis of complex CHD, especially for anomalous vessels and their connections.

Platelet-induced vasomotion of isolated canine coronary artery in the presence of halothane or isoflurane.

To determine the effect of 1.5 MAC of two volatile anesthetics (halothane and isoflurane) on platelet-induced contraction of canine coronary artery, isolated, denuded coronary rings were suspended between two stirrups, placed into organ chambers filled with an oxygenated Krebs-Ringer solution, and connected to an isometric force transducer. Human platelets were obtained from healthy donors and introduced into the organ chambers in increasing amounts to reach 20,50 and, 70 x 10(9) platelets/L. The tension generated in both the control and anesthetic-treated rings was recorded; only halothane reduced the tension induced by platelet activation in the organ chambers. In some experiments, aliquots of Krebs-Ringer solution were taken to determine the amount of 5-HT and TB2 released by 70 x 10(9) human platelets in the presence and absence of the anesthetics. Only halothane reduced TA2 production by the activated platelets. Finally, the contractile response of isolated denuded canine coronary artery rings to U46619, a thromboxane analog, was measured in the presence and absence of the anesthetics. Neither halothane nor isoflurane attenuated the response. In another series of experiments, in vitro platelet aggregation was induced by epinephrine, collagen, ADP, or arachidonic acid in the presence or absence of 1.5 MAC isoflurane or halothane. Both anesthetics significantly reduced the aggregation.

Optimizing conventional cardiac MRI in the rabbit at 0.3 T.

The aim of this study was to define the most efficient way of performing cardiac MRI for anatomic information in small experimental animals, using a vertical magnetic field with a strength of 0.3 T (FONAR beta-3000M). This information may be used to improve cardiac MRI in infants and small children, since the size of a rabbit is considered comparable to that of a neonate. Experimental axial cardiac MRI studies were performed in a rabbit under general anesthesia in order to study the effects on image quality of changing various imaging parameters. These are ECG-gating, number of excitations (averages), number of warp levels, echo time (TE) and repetition time (TR). The effects of changing the size of the field of view (FOV), the slice thickness and the phase-encoding direction were also studied. We found that ECG-gating was crucial and that three excitations, TE 16 ms, and 257 vertical phase-encoding warp levels were adequate. Five-millimeter slice thickness and FOV 20 cm were preferred.

[Functional and morphological study of the pancreatic graft after segmental heterotopic autotransplantation in dogs]. / Etude fonctionnelle et morphologique du greffon pancréatique après autotransplantation segmentaire hétérotopique chez le chien.

Segmentary heterotopic autotransplantation of the body and tail of the pancreas, with visceral exocrine drivation and splenosplenic arterio-venous fistulation, was performed in 12 Beagle dogs. An in vivo glucose tolerance test was conducted before the transplantation and 21 days after the operation. There was a significant decrease in the k coefficient (2.884 +/- 0.234 before and 1.878 +/- 0.128 after transplantation) due to reduced peripheral glucose uptake after transplantation (p < 0.001). Overall glucose-stimulated insulin production was decreased after < 0.001). Two populations were identified retrospectively: in 7 dogs insulin response was satisfactory after transplantation (insulin production > or = 50% pretransplantation level) and in 5 the response was below 50%. Glucose tolerance was tested in vitro in the isolated perfused pancreas transplant in 9 dogs, 30 days after the transplantation. Secretory response was assessed according to the early peak of insulin secretion after glucose stimulation. The patterns of insulin secretion were not different before glucose stimulation but became statistically different after stimulation (p < 0.001). In 5 dogs, the response to in vitro glucose stimulation showed an early peak in insulin secretion and in 4 dogs the insulin response came late with no early peak. On histological examination normal (or subnormal) pancreas grafts and grafts in which extensive sclerosis impaired function could be distinguished. There was a significant correlation between the quality of function and the histology, suggesting that containing post-operative sclerosis to a minimum is an important factor in human transplantations.

Ductus arteriosus aneurysm imaging using modern diagnostic methods.

An aneurysm of the ductus arteriosus carries a high risk of rupture. The radiologic findings are described, based on a review of the literature, and on our experience of 5 patients, successfully diagnosed and treated. A left-sided mediastinal mass is always present, obscured only if the aneurysm has already ruptured. Although the lesion seems to be congenital, conventional radiology sometimes demonstrates wall calcifications. Ultrasonography is well suited to demonstrate the vascular nature of the mass, but interpretation may be difficult because of intervening air-containing lung parenchyma. CT, especially using dynamic scanning with contrast enhancement, is an excellent noninvasive diagnostic method. Angiography is frequently necessary to demonstrate patency or occlusion of the aortic and pulmonary ends of the ductus. The differential diagnosis must include a large number of mediastinal tumors. A temporary widening of the ductus in the newborn is common and must be differentiated from a true aneurysm. Surgical treatment today is usually successful.