High frequency percussive ventilation (HFPV) combines diffusive (high frequency mini-bursts) and convective ventilation patterns. Benefits include enhanced oxygenation and hemodynamics, and alveolar ...recruitment, while providing hypothetic lung-protective ventilation. No study has investigated HFPV-induced changes in lung aeration in patients with early acute respiratory distress syndrome (ARDS).
Eight patients with early non-focal ARDS were enrolled and five swine with early non-focal ARDS were studied in prospective computed tomography (CT) scan and animal studies, in a university-hospital tertiary ICU and an animal laboratory. Patients were optimized under conventional "open-lung" ventilation. Lung CT was performed using an end-expiratory hold (Conv) to assess lung morphology. HFPV was applied for 1 hour to all patients before new CT scans were performed with end-expiratory (HFPV EE) and end-inspiratory (HFPV EI) holds. Lung volumes were determined after software analysis. At specified time points, blood gases and hemodynamic data were collected. Recruitment was defined as a change in non-aerated lung volumes between Conv, HFPV EE and HFPV EI. The main objective was to verify whether HFPV increases alveolar recruitment without lung hyperinflation. Correlation between pleural, upper airways and HFPV-derived pressures was assessed in an ARDS swine-based model.
One-hour HFPV significantly improved oxygenation and hemodynamics. Lung recruitment significantly rose by 12.0% (8.5-18.0%), P = 0.05 (Conv-HFPV EE) and 12.5% (9.3-16.8%), P = 0.003 (Conv-HFPV EI). Hyperinflation tended to increase by 2.0% (0.5-2.5%), P = 0.89 (Conv-HFPV EE) and 3.0% (2.5-4.0%), P = 0.27 (Conv-HFPV EI). HFPV hyperinflation correlated with hyperinflated and normally-aerated lung volumes at baseline: r = 0.79, P = 0.05 and r = 0.79, P = 0.05, respectively (Conv-HFPV EE); and only hyperinflated lung volumes at baseline: r = 0.88, P = 0.01 (Conv-HFPV EI). HFPV CT-determined tidal volumes reached 5.7 (1.1-8.1) mL.kg
of ideal body weight (IBW). Correlations between pleural and HFPV-monitored pressures were acceptable and end-inspiratory pleural pressures remained below 25cmH
0.
HFPV improves alveolar recruitment, gas exchanges and hemodynamics of patients with early non-focal ARDS without relevant hyperinflation. HFPV-derived pressures correlate with corresponding pleural or upper airways pressures.
ClinicalTrials.gov, NCT02510105 . Registered on 1 June 2015. The trial was retrospectively registered.
Purpose
Immunotherapy has dramatically improved the prognosis of patients with metastatic melanoma (MM). Yet, there is a lack of biomarkers to predict whether a patient will benefit from ...immunotherapy. Our aim was to create radiomics models on pretreatment computed tomography (CT) to predict overall survival (OS) and treatment response in patients with MM treated with anti-PD-1 immunotherapy.
Methods
We performed a monocentric retrospective analysis of 503 metastatic lesions in 71 patients with 46 radiomics features extracted following lesion segmentation. Predictive accuracies for OS < 1 year versus > 1 year and treatment response versus no response was compared for five feature selection methods (sequential forward selection, recursive, Boruta, relief, random forest) and four classifiers (support vector machine (SVM), random forest, K-nearest neighbor, logistic regression (LR)) used with or without SMOTE data augmentation. A fivefold cross-validation was performed at the patient level, with a tumour-based classification.
Results
The highest accuracy level for OS predictions was obtained with 3D lesions (0.91) without clinical data integration when combining Boruta feature selection and the LR classifier, The highest accuracy for treatment response prediction was obtained with 3D lesions (0.88) without clinical data integration when combining Boruta feature selection, the LR classifier and SMOTE data augmentation. The accuracy was significantly higher concerning OS prediction with 3D segmentation (0.91 vs 0.86) while clinical data integration led to improved accuracy notably in 2D lesions (0.76 vs 0.87) regarding treatment response prediction. Skewness was the only feature found to be an independent predictor of OS (HR (CI 95%) 1.34,
p
-value 0.001).
Conclusion
This is the first study to investigate CT texture parameter selection and classification methods for predicting MM prognosis with treatment by immunotherapy. Combining pretreatment CT radiomics features from a single tumor with data selection and classifiers may accurately predict OS and treatment response in MM treated with anti-PD-1.
Objective
Shunt malfunctions seem more frequent in children (44 to 81%) than in adults (18 to 29%). Because of discrepancies between studies, it is not possible to affirm this disparity. The ...objective was to verify whether the incidence of cerebrospinal fluid (CSF) shunt malfunctions is higher in children than adults.
Methods
We present a retrospective series of child and adult patients who underwent CSF shunt placement between 2000 and 2013 with a Sophysa SM8® valve.
Results
599 adults and 98 children (sex ratio 1.28) underwent CSF shunt placement. Age at first surgery ranged between 1 day of life and 90 years (mean of 55.8 years, SD 25.8, median 64.8 years). The mean follow-up was 4 years (SD 4.264, 0–16; median 3 years). The cumulative complication rate was 25.5% (178/697). Mechanical complications were disconnection (25.1%), migration (11.8%), intracranial catheter obstruction (8.9%) and malposition (8.4%). The mean delay for the first revision was 1.90 years (0–13.9), (SD 2.73, median 0.5). The probability of shunt failure was 65% at 10 years in the child group and 36% at 10 years in the adult group. Moreover, in the child group, 33% of revisions occurred during the first year after shunt placement versus 17% in the adult group. Thus, the probability of shunt failure was higher in children than in adults (log-rank test,
p
< 0.001).
Conclusions
This is the first retrospective study, comparing children and adults undergoing CSF shunt using the same valve, able to confirm the higher rate of complications in children.
Abstract
BACKGROUND:
To date, no study has compared the evolution of the foramen magnum area (FMA) and the posterior cranial fossa volume (PCFV) with the degree of cranial base synchondrosis ...ossification.
OBJECTIVE:
To illustrate these features in healthy children.
METHODS:
The FMA, the PCFV, and the ossification of 12 synchondroses according to the Madeline and Elster scale were retrospectively analyzed in 235 healthy children using millimeter slices on a computed tomography scan.
RESULTS:
The mean FMA of 6.49 cm2 in girls was significantly inferior to the FMA of 7.67 cm2 in boys (P <.001). In both sexes, the growth evolved in a 2-phase process, with a phase of rapid growth from birth to 3.75 years old (yo) followed by a phase of stabilization. In girls, the first phase was shorter (ending at 2.6 yo) than in boys (ending at 4.33 yo) and proceeded at a higher rate. PCFV was smaller in girls (P <.001) and displayed a biphasic pattern in the whole population, with a phase of rapid growth from birth to 3.58 yo followed by a phase of slow growth until 16 yo. In girls, the first phase was more active and shorter (ending at 2.67 yo) than in boys (ending at 4.5 yo). The posterior interoccipital synchondroses close first, followed by the anterior interoccipital and occipitomastoidal synchondroses, the lambdoid sutures simultaneously, then the petro-occipital and spheno-occipital synchondroses simultaneously.
CONCLUSION:
The data provide a chronology of synchondrosis closure. We showed that FMA and PCFV are constitutionally smaller in girls at birth (P ⩽.02) and suggest that a sex-related difference in the FMA is related to earlier closure of anterior interoccipital synchondroses in girls (P =.01).
Objectives
To describe computed tomography (CT) scanning parameters, volume CT dose index (CTDIvol) and dose-length product (DLP) in paediatric practice and compare them to current diagnostic ...reference levels (DRLs).
Methods
The survey was conducted in radiology departments of six major university hospitals in France in 2010–2013. Data collection was automatised to extract and standardise information on scanning parameters from DICOM-header files. CTDIvol and DLP were estimated based on Monte Carlo transport simulation and computational reference phantoms.
Results
CTDIvol and DLP were derived for 4,300 studies, four age groups and 18 protocols. CTDIvol was lower in younger patients for non-head scans, but did not vary with age for routine head scans. Ratios of 95th to 5th percentile CTDIvol values were 2–4 for most body parts, but 5–7 for abdominal examinations and 4–14 for mediastinum CT with contrast, depending on age. The 75th percentile CTDIvol values were below the national DRLs for chest (all ages) and head and abdominal scans (≥10 years).
Conclusion
The results suggest the need for a better optimisation of scanning parameters for routine head scans and infrequent protocols with patient age, enhanced standardisation of practices across departments and revision of current DRLs for children.
Key points
• CTDIvol varied little with age for routine head scans.
• CTDIvol was lowest in youngest children for chest or abdominal scans.
• Individual and inter-department variability warrant enhanced standardisation of practices.
• Recent surveys support the need for revised diagnostic reference levels.
• More attention should be given to specific protocols (sinuses, neck, spine, mediastinum).
Surgical correction of nonsyndromic craniosynostosis (NSC) aims to restore cranial shape. Reossification of bone defects is paramount for the best aesthetic prognosis. However, the literature on the ...quantitative evaluation of bone defects after NSC surgery is scarce. This study aimed to quantify and analyze the surface area of bone defects after NSC surgery and establish a threshold value for predicting persistent defects.
We conducted a systematic review and a prospective study of 28 children undergoing surgical treatment for NSC. We analyzed 426 defects on the first computed tomography scan (1 year postoperative) and 132 defects on the second computed tomography scan (4.6 years postoperative). Statistical analysis was performed using Spearman's rank correlation coefficient, Mann-Whitney-Wilcoxon rank-sum test, and Youden's J statistic.
Our systematic review identified three studies reporting on bone defects' surface area and reossification rate. In our study, we found no statistically significant differences in the number or size of defects between sex or type of NSC. The threshold value for the surface area of bone defects above which there was a higher probability of persistent defects was 0.19 cm2 (Youden point), with an 89.47 % probability of persistence. Defects with a surface area below 0.19 cm2 had a considerably lower probability, only 15.07%, of persistence over time.
Our study provides valuable quantitative data for managing bone defects after NSC surgery. Defects with a surface area above 0.19 cm2 should be monitored with radiological imaging because of the risk of persistence. Our findings highlight the importance of developing robust and reproducible methods for the quantitative analysis of bone defects after NSC surgery.
Epithelioid hemangioendothelioma of the liver is a very rare vascular tumour in children with intermediate malignant potential. We present a case in which the typical imaging appearances of ...coalescent peripheral hepatic masses with capsular retraction contributed to the diagnosis. A positron emission tomography-CT (PET-CT) procedure was performed in staging the disease with a strong suspicion of coeliac nodal involvement confirmed after laparotomy and histological analysis. Our case is unique because of the rarity of the disease, the young age of the child, and proven nodal metastases at initial diagnosis. The use of PET-CT allows better staging at initial diagnosis and thus better management with improved follow-up in these patients.
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