Structured reporting in fetal magnetic resonance imaging with congenital diaphragmatic hernia.

OBJECTIVE: We aim to provide a template structured report of fetal Magnetic Resonance Imaging in congenital diaphragmatic hernia (CDH) that was locally validated by the CDH study group in Mannheim. METHODS: A selection of 50 fetal MRIs of patients with an isolated diaphragmatic hernia and associated radiology reports from five different senior radiologists from a single center resulted in a primary structured report, which was put into practice by using dedicated software. A questionnaire survey of the interdisciplinary CDH study group Mannheim was used to adapt the report to the clinical requirements. RESULTS: There was a huge variability in how deep the free text reports go into detail. The side of the hernia was named in 94% of cases. In 58%, both the lung volume and the total lung volume were reported. A comparison with the expected lung volume was reported in 66% of cases. Additional findings, such as herniated organs, were reported in 96% of cases. Overall satisfaction with the newly established structured report was high within the CDH study group with a mean of 4.7. CONCLUSIONS: The use of the structured report of this study can optimize the interdisciplinary dialog, the standardization of report content, increase report completeness and improve quality.

[Testicular tumors in prepubertal boys-organ preservation possible more often than expected]. / Hodentumoren bei präpubertären Jungen ­ Organerhalt häufiger möglich als gedacht.

In prepubertal boys, testicular tumors are rare with an incidence between 2 and 5/million. In contrast to testicular tumors in adolescents and adults, more than 2/3 of these tumors are benign. Unfortunately, in Germany in most cases, only malignant tumors (usually yolk sac tumors) are reported to the study center (MAKEI IV and now V). Therefore, the incidence in Germany is unknown. Since the introduction of polychemotherapy in the 1970s, the prognosis of malignant testicular tumors has improved enormously and has become a curable disease, even in the case of recurrence. Today the orchiectomy, which was usually carried out in the past, appears to be no longer justified in most prepubertal boys due to the high incidence of benign tumors. It has been shown in various studies that organ-sparing surgery in germ cell tumors (epidermoid cysts, teratoma); gonadal stoma tumors (Sertoli, Leydig and granulosa cell tumors) and cystic lesions (intratesticular cysts and tubular ectasia of the rete testis) is reliable and safe. In cases with preoperative significantly increased AFP (caution: norm values not valid in the first year of life) and a clear testicular tumor in the ultrasound (yolk sac tumor) or if no testicular parenchyma is sonographically detectable, orchiectomy can still be carried out. Today orchiectomies in prepubertal boys should be an exception and the reasons for an orchiectomy must be well documented.

Region of interest-based versus whole-lung segmentation-based approach for MR lung perfusion quantification in 2-year-old children after congenital diaphragmatic hernia repair.

OBJECTIVE: With a region of interest (ROI)-based approach 2-year-old children after congenital diaphragmatic hernia (CDH) show reduced MR lung perfusion values on the ipsilateral side compared to the contralateral. This study evaluates whether results can be reproduced by segmentation of whole-lung and whether there are differences between the ROI-based and whole-lung measurements. METHODS: Using dynamic contrast-enhanced (DCE) MRI, pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) were quantified in 30 children after CDH repair. Quantification results of an ROI-based (six cylindrical ROIs generated of five adjacent slices per lung-side) and a whole-lung segmentation approach were compared. RESULTS: In both approaches PBF and PBV were significantly reduced on the ipsilateral side (p always <0.0001). In ipsilateral lungs, PBF of the ROI-based and the whole-lung segmentation-based approach was equal (p=0.50). In contralateral lungs, the ROI-based approach significantly overestimated PBF in comparison to the whole-lung segmentation approach by approximately 9.5 % (p=0.0013). CONCLUSIONS: MR lung perfusion in 2-year-old children after CDH is significantly reduced ipsilaterally. In the contralateral lung, the ROI-based approach significantly overestimates perfusion, which can be explained by exclusion of the most ventral parts of the lung. Therefore whole-lung segmentation should be preferred. KEY POINTS: • Ipsilaterally, absolute lung perfusion after CDH is reduced in whole-lung analysis. • Ipsilaterally, the ROI- and whole-lung-based approaches generate identical results. • Contralaterally, the ROI-based approach significantly overestimates perfusion results. • Whole lung should be analysed in MR lung perfusion imaging. • MR lung perfusion measurement is a radiation-free parameter of lung function.

High temporal versus high spatial resolution in MR quantitative pulmonary perfusion imaging of two-year old children after congenital diaphragmatic hernia repair.

OBJECTIVES: Congenital diaphragmatic hernia (CDH) leads to lung hypoplasia. Using dynamic contrast-enhanced (DCE) MR imaging, lung perfusion can be quantified. As MR perfusion values depend on temporal resolution, we compared two protocols to investigate whether ipsilateral lung perfusion is impaired after CDH, whether there are protocol-dependent differences, and which protocol is preferred. METHODS: DCE-MRI was performed in 36 2-year old children after CDH on a 3 T MRI system; protocol A (n = 18) based on a high spatial (3.0 s; voxel: 1.25 mm(3)) and protocol B (n = 18) on a high temporal resolution (1.5 s; voxel: 2 mm(3)). Pulmonary blood flow (PBF), pulmonary blood volume (PBV), mean transit time (MTT), and peak-contrast-to-noise-ratio (PCNR) were quantified. RESULTS: PBF was reduced ipsilaterally, with ipsilateral PBF of 45 ± 26 ml/100 ml/min to contralateral PBF of 63 ± 28 ml/100 ml/min (p = 0.0016) for protocol A; and for protocol B, side differences were equivalent (ipsilateral PBF = 62 ± 24 vs. contralateral PBF = 85 ± 30 ml/100 ml/min; p = 0.0034). PCNR was higher for protocol B (30 ± 18 vs. 20 ± 9; p = 0.0294). Protocol B showed higher values of PBF in comparison to protocol A (p always <0.05). CONCLUSIONS: Ipsilateral lung perfusion is reduced in 2-year old children following CDH repair. Higher temporal resolution and increased voxel size show a gain in PCNR and lead to higher perfusion values. Protocol B is therefore preferred. KEY POINTS: • Quantitative lung perfusion parameters depend on temporal and spatial resolution. • Reduction of lung perfusion in CDH can be measured with different MR protocols. • Temporal resolution of 1.5 s with spatial resolution of 2 mm (3) is suitable.

Quantitative pulmonary perfusion imaging at 3.0 T of 2-year-old children after congenital diaphragmatic hernia repair: initial results.

OBJECTIVE: To investigate whether dynamic contrast-enhanced MR imaging of the lung following congenital diaphragmatic hernia repair is feasible at 3.0 T in 2-year-old children and whether associated lung hypoplasia (reflected in reduced pulmonary microcirculation) can be demonstrated in MRI. METHODS: Twelve children with a mean age 2.0 ± 0.2 years after hernia repair underwent DCE-MRI at 3.0 T using a time-resolved angiography with stochastic trajectories sequence. Quantification of lung perfusion was performed using a pixel-by-pixel deconvolution approach. Six regions of interest were placed (upper, middle and lower parts of right and left lung) to assess differences in pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) while avoiding the inclusion of larger pulmonary arteries and veins. RESULTS: The difference in PBF and PBV between ipsilateral and contralateral lung was significant (P < 0.5). No significant differences could be detected for the MTT (P = 0.5). CONCLUSION: DCE-MRI in 2-year-old patients is feasible at 3.0 T. Reduced perfusion in the ipsilateral lung is reflected by significantly lower PBF values compared with the contralateral lung. DCE-MRI of the lung in congenital diaphragmatic hernia can help to characterise lung hypoplasia initially and in the long-term follow-up of children after diaphragmatic repair. KEY POINTS: Congenital diaphragmatic hernia often leads to lung hypoplasia and secondary pulmonary hypertension. Dynamic contrast-enhanced 3-T magnetic resonance can assess these complications in 2-year-olds. The affected ipsilateral lung shows reduced perfusion and lower pulmonary blood flow. Thoracic DCE-MRI helps characterise lung hypoplasia in children after hernia repair.

Prediction of chronic lung disease, survival and need for ECMO therapy in infants with congenital diaphragmatic hernia: additional value of fetal MRI measurements?

INTRODUCTION: The lung-to-head ratio (LHR), measured by ultrasound, and the fetal lung volume (FLV), measured by MRI, are both used to predict survival and need for extra corporeal membrane oxygenation (ECMO) in infants with congenital diaphragmatic hernia (CDH). The aim of this study is to determine whether MRI measurements of the FLV, in addition to standard ultrasound measurements of the LHR, give better prediction of chronic lung disease, mortality by day 28 and need for ECMO. MATERIALS AND METHODS: Patients with unilateral isolated CDH born between January 2002 and December 2008 were eligible for inclusion. LHR and FLV were expressed as observed-to-expected values (O/E LHR and O/E FLV). Univariate and multivariate analyses were performed. Receiver operating characteristic curves were constructed and areas under the curve (AUC) were calculated to determine predictive values. RESULTS: 90 patients were included in the analysis. Combined measurement of the O/E LHR and O/E FLV gave a slightly better prediction of chronic lung disease (AUC=0.83 and AUC=0.87) and need for ECMO therapy (AUC=0.77 and AUC=0.81) than standard ultrasound measurements of the O/E LHR alone. Combined measurement of the O/E LHR and O/E FLV did not improve prediction of early mortality (AUC=0.90) compared to measurement of the O/E LHR alone (AUC=0.89). An intrathoracal position of the liver was independently associated with a higher risk of early mortality (p<0.001), chronic lung disease (p=0.007) and need for ECMO therapy (p=0.001). DISCUSSION: Chronic lung disease and need for ECMO therapy are slightly better predicted by combined measurement of the O/E LHR and the O/E FLV. Early mortality is very well predicted by measurement of the O/E LHR alone. CONCLUSION: Clinical relevance of additional MRI measurements may be debated.

[A child's birthday with consequences]. / Ein Kindergeburtstag mit folgen.

Foreign body ingestion is a common pediatric emergency and if the foreign body cannot be detected radiologically or endoscopically further investigations are required. In this article the case of a radiolucent, ingested foreign body (mini-candleholder of a birthday cake) is presented. The foreign body could not initially be identified via X-ray and endoscopy due to its parapharyngeal localization but was finally visualized by magnetic resonance imaging (MRI) which additionally uncovered the co-existence of acute mediastinal inflammation.

Long-term outcome in patients with short bowel syndrome after longitudinal intestinal lengthening and tailoring.

OBJECTIVES: Longitudinal intestinal lengthening and tailoring (LILT) is a well-established surgical treatment for short bowel syndrome. It has been shown to enhance peristalsis, decrease bacterial overgrowth, and extend mucosal contact time for nutrients. We present the results of a long-term follow-up of patients who underwent LILT and define prognostic parameters for the survival of these patients. PATIENTS AND METHODS: Between 1987 and 2006, 53 patients underwent LILT in our institution. The main diagnoses were gastroschisis, intestinal volvulus, intestinal atresias, and necrotizing enterocolitis. LILT was performed at a mean age of 24 months (range 4144 months). The follow-up time was 79.76 months (range 6234 months). RESULTS: After LILT, 41 of 53 patients survived, and 36 of 41 surviving patients were successfully weaned from parenteral nutrition (PN). In long-term follow-up 79% stayed free of PN. The overall survival rate was 77.36%. Weight gain occurred in 58% of the patients after LILT. The quality of life after LILT is on a high level, with most patients having normal physical strength and participating in normal social life and education. Prognostic factors for survival after LILT in short bowel syndrome are length of small intestine (0.06582 + 0.0131 x bowel cm), length of large bowel (P = 0.039), preoperative liver function, and successful weaning from PN within 18 months postoperatively (P = 0.0032). CONCLUSIONS: Patients undergoing LILT in short bowel syndrome have a high survival rate, weight gain, and a high quality of life. Autologous gastrointestinal reconstruction remains therefore the first choice in the treatment of patients with short bowel syndrome.

The impact of longitudinal intestinal lengthening and tailoring on liver function in short bowel syndrome.

INTRODUCTION: Short bowel syndrome is a functional or anatomic loss of major parts of the small bowel leading to severe malnutrition. The limiting factor for the survival of these patients remains parenteral nutrition-related liver damage leading to end-stage liver failure. Longitudinal intestinal lengthening and tailoring (LILT) has been proven to enhance peristalsis, to decrease bacterial overgrowth and to extend the mucosal contact time for the absorption of nutrients. The aim of this study was to show the impact of LILT on the development of parenteral nutrition-related liver damage. PATIENTS AND METHODS: A cohort of 55 patients with short bowel syndrome managed with LILT in our institution between 1987 and 2007 was retrospectively reviewed. LILT was performed at a mean age of 24 months (range 4 - 150 months). Mean follow-up time was 83.76 months (range 5 - 240 months). We obtained reliable data from 31 patients with regard to liver enzymes and function parameters in blood samples before LILT and at the present time. Liver biopsy was performed in 14 patients prior to LILT. RESULTS: Liver enzymes ALAT (mean 121 U/l), ASAT (mean 166 U/l) and bilirubin (mean 2.49 mg/dl) were elevated preoperatively in 27/31 children. After the lengthening procedure, ALAT (mean 50 U/l), ASAT (mean 63 U/l) and bilirubin (mean 1.059 mg/dl) normalized except in 5 of 8 patients who could not be weaned from parenteral nutrition after LILT. Liver function parameters such as the international normal ratio (INR) were slightly elevated in 5/31 patients. Albumin was generally low, probably due to parenteral nutrition. Liver biopsy was performed in 14 patients preoperatively, showing 4 patients with low-grade, 6 patients with intermediate and 4 patients with high-grade fibrosis. End-stage liver disease with cirrhosis was an exclusion criterion for LILT. All patients with liver fibrosis showed a normalization of liver enzymes when they were weaned from parenteral nutrition. But patients with higher grade liver fibrosis tend to develop more complications perioperatively. CONCLUSION: After LILT, all patients with liver fibrosis who could be weaned from parenteral nutrition showed a normalization of liver enzymes. Preoperative liver biopsy is mandatory in order to differentiate reversible liver fibrosis from end-stage liver disease. A higher grade of liver fibrosis and elevated INR has been shown to be a sensitive parameter for peri- and postoperative complications.

Mechanical properties of 18 different AO bone plates and the clamp-rod internal fixation system tested on a gap model construct.

OBJECTIVE: To compare the stiffness and strength of AO bone plates (DCP, LC-DCP, VCP, RCP, and LP) and the Clamp-Rod Internal Fixation System (CRIF). STUDY DESIGN: In vitro. SAMPLE SIZE: 12 individual implants of 18 plate dimensions and four sizes of CRIF, each corresponding to 2.0, 2.4/2.7, 3.5, or 4.5 mm screw sizes. METHODS: Implant-constructs of each plate and CRIF were created using Canevasit rods as a bone substitute in an unstable gap fracture model. Six implant-constructs of each type were tested under single cycle four-point bending loading, and six were tested under single cycle torsional loading until permanent plastic deformation occurred. RESULTS: Torsional stiffness and yield load of the DCP were always significantly greater than the CRIF within the same group. Bending properties of the 2.0 DCP were not significantly different to the 2.0 CRIF. The 2.7 DCP had significantly higher bending values than the 2.7 CRIF. The bending stiffness of the 3.5 DCP and 4.5 DCP was significantly less than their CRIF counterparts. While the bending yield load of the 3.5 DCP was significantly greater than the 3.5 CRIF, the bending yield load of the 4.5 DCP was significantly less than the 4.5 CRIF. CONCLUSION: A weakness was found in the torsional resistance of the CRIF constructs compared to the DCP constructs. CLINICAL SIGNIFICANCE: Bone holding power and applied screw torque should be considered when using the CRIF system in clinical application.

Dowel pinning for feline metacarpal and metatarsal fractures.

The goal of this retrospective study was to describe dowel pinning, and to compare the results of osteosynthesis and external coaptation of metacarpal and metatarsal fractures in cats. Evaluation of the medical records of 351 cats yielded 63 cats treated with dowel pinning, 35 cats treated with external coaptation and 14 cats treated with both methods within the same limb. All of the cats had been re-evaluated at an average of 2.8 years (six months - 15 years) postoperatively. Dowel pinning was superior to external coaptation when all fractured bones of a limb could be pinned. When internal fixation of multiple fractures was not feasible in all fractured bones due to comminution or fragments that were too short to pin, the outcome was not significantly different from cases treated with external coaptation alone. Malunion was seen in 16% of fractured bones in cats treated with external coaptation and occurred secondary to implant bending in 3% of fractured bones treated with dowel pinning. The latter refers to one operated cat, which had four metacarpal fractures in the same limb. Radiographs taken at re-evaluation showed implant migration within the medullary canal in two cats, although neither showed any signs of non-union or lameness. Non-union was seen in one operated cat, in which the fracture (MC IV) could not be completely reduced with a K-wire. Osteomyelitis did not occur. Dowel pinning is an easy, inexpensive and effective technique for repair of metacarpal and metatarsal fractures in cats.

Experimental realization of a model glass former in 2D.

We have studied binary two-dimensional (2D) mixtures of superparamagnetic colloidal particles interacting through magnetic dipole moments, which were induced by an external magnetic field B. By tuning B the effective system temperature could be widely adjusted. Time-dependent particle coordinates measured by video-microscopy provide radial pair-distribution functions, mean-square displacements as well as evidence for heterogeneous dynamics. Characteristic features of 3D glass formers are observed experimentally in 2D for the first time.

Elastic behavior of a two-dimensional crystal near melting.

Using positional data from video microscopy, we determine the elastic moduli of two-dimensional colloidal crystals as a function of temperature. The moduli are extracted from the wave-vector-dependent normal-mode spring constants in the limit q-->0 and are compared to the renormalized Young's modulus of the Kosterlitz-Thouless-Halperin-Nelson-Young theory. An essential element of this theory is the universal prediction that Young's modulus must approach 16 pi at the melting temperature. This is indeed observed in our experiment.

Three-particle correlations in simple liquids.

We use videomicroscopy to follow the phase-space trajectory of a two-dimensional colloidal model liquid and calculate three-point correlation functions from the measured particle configurations. Approaching the fluid-solid transition by increasing the strength of the pair-interaction potential, one observes the gradual formation of a crystal-like local order due to triplet correlations, while being still deep inside the fluid phase. Furthermore, we show that in a strongly interacting system the Born-Green equation can be satisfied only with the full triplet correlation function but not with three-body distribution functions obtained from superposing pair correlations (Kirkwood superposition approximation).

Elastic properties of 2D colloidal crystals from video microscopy.

Elastic constants of two-dimensional (2D) colloidal crystals are determined by measuring strain fluctuations induced by Brownian motion of particles. Paramagnetic colloids confined to an air-water interface of a pendant drop are crystallized under the action of a magnetic field, which is applied perpendicular to the 2D layer. Using video microscopy and digital image processing we measure fluctuations of the microscopic strain obtained from random displacements of the colloidal particles from their mean (reference) positions. From these we calculate system-size dependent elastic constants, which are extrapolated using finite-size scaling to obtain their values in the thermodynamic limit. The data are found to agree rather well with zero-temperature calculations.

Mechanics of venom expulsion in Crotalus, with special reference to the role of the fang sheath.

A combination of anatomical and experimental preparations were used to explore the function of the venom delivery system in rattlesnakes (Crotalus). The distal end of the venom duct is compressed near the point where it empties into the venom chamber, a space surrounding the fang defined by the fang sheath. Within the venom chamber, the inner fang membrane lies obliquely over the base of the fang at least partially occluding the entrance orifice. When the fang is retracted the combination of the compressed venom duct and the spatial position of the inner fang membrane serve to inhibit or block venom flow. As the fang is erected beyond approximately 60 degrees (relative to the roof of the mouth) localized compression of the fang sheath decreases the size of the venom chamber, relieves the compressive force from the venom duct, and displaces the inner fang membrane away from the entrance orifice of the fang. Pressure recordings taken at different locations along the venom delivery system demonstrate that the venom gland produces suction during relaxation of the extrinsic glandular musculature. These findings suggest that the venom delivery system of Crotalus is both more flexible and more regulated than previously assumed.

New LightCycler PCR for rapid and sensitive quantification of parvovirus B19 DNA guides therapeutic decision-making in relapsing infections.

Detection of parvovirus B19 DNA offers diagnostic advantages over serology, particularly in persistent infections of immunocompromised patients. A rapid, novel method of B19 DNA detection and quantification is introduced. This method, a quantitative PCR assay, is based on real-time glass capillary thermocycling (LightCycler [LC]) and fluorescence resonance energy transfer (FRET). The PCR assay allowed quantification over a dynamic range of over 7 logs and could quantify as little as 250 B19 genome equivalents (geq) per ml as calculated for plasmid DNA (i.e., theoretically >or=5 geq per assay). Interrater agreement analysis demonstrated equivalence of LC-FRET PCR and conventional nested PCR in the diagnosis of an active B19 infection (kappa coefficient = 0.83). The benefit of the new method was demonstrated in an immunocompromised child with a relapsing infection, who required an attenuation of the immunosuppressive therapy in addition to repeated doses of immunoglobulin to eliminate the virus.

Structure, expression and products of the ribosomal RNA operons of Rhodopseudomonas palustris No. 7.

Rhodopseudomonas palustris strains carry one or two ribosomal rRNA operons, and those with duplicated rrn operons grow faster. The two rrn operons in R. palustris No. 7 are virtually identical over a 54,70-bp stretch containing the genes for 16S rRNA, tRNAile, tRNAala, 23S rRNA and 5S rRNA, as well as the intergenic spacers and part of the extragenic spacer. In R. palustris, unlike most bacteria with multiple rrn operons, the putative promoter sequences of the two operons are highly diverged, suggesting possible functional differentiation. By simultaneous primer-extension analysis of both pre-rRNAs, we detected a two-fold higher level of expression from rrnA under photoautotrophic conditions. Alteration of the conditions of growth leads to changes in the relative levels of expression of the two operons. Within the 5,470-bp segment, only two sequence differences are found between the 23S rRNA genes; one is at the center of the 23S rRNA molecule and affects a site of unknown function, and the other is within or immediately adjacent to sequences involved in processing of the 5' 23S rRNA IVS. In vitro processing of 5' IVS-containing 23S rRNA precursors from each operon does not reveal any detectable difference between them. The 5' ends of the mature 16S, 23S, and 5S rRNAs were determined by primer-extension analysis, and the 3' end of 23S rRNA was determined by RNA linker ligation-mediated cDNA cloning. The 5' and 3' ends of the R. palustris 23S rRNA molecule are extensively processed, suggesting that, unlike the situation in the established eubacterial model, these ends cannot basepair.

Venom flow in rattlesnakes: mechanics and metering.

The functional morphology of venom injection in Crotalus atrox was explored using high-speed digital videography combined with direct recording of venom flow using perivascular flow probes. Although venom flow was variable, in most strikes the onset of venom flow was coincidental with fang penetration, and retrograde flow (venom suction) was observed prior to fang withdrawal. The duration of venom flow was consistently less than the duration of fang penetration. The occurrence of retrograde flow, 'dry bites' (which accounted for 35 % of the strikes) and unilateral strikes all support a hypothesis for venom pooling in the distal portion of the venom-delivery system. No significant difference in temporal or volumetric aspects of venom flow were found between defensive strikes directed at small and large rodents. With the species and size of target held constant, the duration of venom flow, maximum venom flow rate and total venom volume were all significantly lower in predatory than in defensive strikes.