MRI after Bonebridge implantation: a comparison of two implant generations.

PURPOSE: Analysis of head magnetic resonance images (MRI) of patients with active bone conduction implants (BCIs) is challenging. Currently, there are two generations of the transcutaneous Bonebridge system (BCI601 and BCI602), the main difference between them being the transducer design and thickness. The aim was to compare the effect of transducer placement and artifact reduction sequences on legibility of MRI scans. METHODS: Four Thiel-fixed human head specimens were used: BCI601 was implanted in sinodural and middle fossa placement, and BCI602 in middle fossa and retrosigmoid approach. Images were obtained with a Signa® 1.5T MR. A metal artifact reduction sequence known as MAVRIC (multiacquisition variable-resonance image combination) was used. Each specimen was scanned using standard axial T2 SE and compared with axial MAVRIC artifact reduction sequences. RESULTS: Qualitatively, limits of the artifact produced by the implant were better defined with MAVRIC than with standard T2 sequences. Assessment of contralateral internal auditory canal (IAC) was possible in all cases. Placement of the BCI602 in the middle fossa allowed the view of the ipsilateral IAC using MAVRIC sequence. Quantitatively, the artifact was reduced with MAVRIC sequence from 6.3 to 59.7%, depending on the position of implant and model; the middle fossa placement and the BCI602 being those generating shorter artifact radio. CONCLUSION: Artifact optimized sequences as MAVRIC reduce the artifact caused by the Bonebridge system. The middle fossa approach allows a better visualization of IAC canal in the ipsilateral ear with both implant versions, but the effect is more prominent with the BCI602.

Norovirus-associated White Matter Injury in a Term Newborn With Seizures.

Neonatal seizures with white matter injury have been associated with rotavirus, enterovirus and parechovirus. Neurological symptoms caused by norovirus have been occasionally reported in older children. We describe a case of a neonate with seizures and white matter lesions, with detection of human norovirus in stool samples from the patient and her mother.

Effect of Dynamic Hyperinflation on Cardiac Response to Exercise of Patients With Chronic Obstructive Pulmonary Disease.

INTRODUCTION: Although the major limitation to exercise performance in patients with COPD is dynamic hyperinflation (DH), little is known about its relation with cardiac response to exercise. Our objectives were to compare the exercise response of stroke volume (SV) and cardiac output (CO) between COPD patients with or without DH and control subjects, and to assess the main determinants. METHODS: Fifty-seven stable COPD patients without cardiac comorbidity and 25 healthy subjects were recruited. Clinical evaluation, baseline function tests, computed tomography and echocardiography were conducted in all subjects. Patients performed consecutive incremental exercise tests with measurement of operating lung volumes and non-invasive measurement of SV, CO and oxygen uptake (VO2) by an inert gas rebreathing method. Biomarkers of systemic inflammation and oxidative stress, tissue damage/repair, cardiac involvement and airway inflammation were measured. RESULTS: COPD patients showed a lower SV/VO2 slope than control subjects, while CO response was compensated by a higher heart rate increase. COPD patients with DH experienced a reduction of SV/VO2 and CO/VO2 compared to those without DH. In COPD patients, the end-expiratory lung volume (EELV) increase was related to SV/VO2 and CO/VO2 slopes, and it was the only independent predictor of cardiac response to exercise. However, in the regression models without EELV, plasma IL-1ß and high-sensitivity cardiac troponin T were also retained as independent predictors of SV/VO2 slope. CONCLUSION: Dynamic hyperinflation decreases the cardiac response to exercise of COPD patients. This effect is related to systemic inflammation and myocardial stress but not with left ventricle diastolic dysfunction.

Small Airway Dysfunction Impairs Quality of Life Among Smokers With No Airflow Limitation. / La disfunción de las pequeñas vías aéreas deteriora la calidad de vida de fumadores sin limitación al flujo aéreo.

INTRODUCTION: Small airway dysfunction (SAD) caused by smoking contributes to the early onset of airflow limitation (AFL), although its impact on patients' perception of health is largely unknown. We aimed to evaluate the frequency of SAD in active smokers without AFL, and to compare health-related quality of life (HRQoL) of non-smokers, smokers without SAD, smokers with SAD, and smokers with AFL. METHODS: A total of 53 active smokers without AFL, 20 smokers with AFL, and 20 non-smokers completed the SF-36 and EuroQoL questionnaires and performed impulse oscillometry and spirometry. Pulmonary parenchymal attenuation was determined in inspiration and expiration. SAD was determined to exist when resistance at 5Hz (R5), the difference between R5 and R20, and reactance area (AX) exceeded the upper limit of normal. RESULTS: In total, 35.8% of smokers without AFL had SAD. No differences were detected in spirometric parameters or pulmonary attenuation between smokers with or without AFL and non-smokers. However, smokers with SAD had worse scores on HRQoL questionnaires than smokers without SAD or non-smokers, and scores compared to smokers with AFL were intermediate. R5 and X5 were identified as independent determinants of HRQoL in smokers without AFL. CONCLUSIONS: SAD is common in smokers without AFL, affecting one third of this population, and independently affecting their perception of health.

Assessment of Pre-operative Measurements of Tumor Size by MRI Methods as Survival Predictors in Wild Type IDH Glioblastoma.

Objective: We evaluate the performance of three MRI methods to determine non-invasively tumor size, as overall survival (OS) and Progression Free Survival (PFS) predictors, in a cohort of wild type, IDH negative, glioblastoma patients. Investigated protocols included bidimensional (2D) diameter measurements, and three-dimensional (3D) estimations by the ellipsoid or semi-automatic segmentation methods. Methods: We investigated OS in a cohort of 44 patients diagnosed with wild type IDH glioblastoma (58.2 ± 11.4 years, 1.9/1 male/female) treated with neurosurgical resection followed by adjuvant chemo and radiotherapy. Pre-operative MRI images were evaluated to determine tumor mass area and volume, gadolinium enhancement volume, necrosis volume, and FLAIR-T2 hyper-intensity area and volume. We implemented then multivariate Cox statistical analysis to select optimal predictors for OS and PFS. Results: Median OS was 16 months (1-42 months), ranging from 9 ± 2.4 months in patients over 65 years, to 18 ± 1.6 months in younger ones. Patients with tumors carrying O6-methylguanin-DNA-methyltransferase (MGMT) methylation survived 30 ± 5.2 vs. 13 ± 2.5 months in non-methylated. Our study evidenced high and positive correlations among the results of the three methods to determine tumor size. FLAIR-T2 hyper-intensity areas (2D) and volumes (3D) were also similar as determined by the three methods. Cox proportional hazards analysis with the 2D and 3D methods indicated that OS was associated to age ≥ 65 years (HR 2.70, 2.94, and 3.16), MGMT methylation (HR 2.98, 3.07, and 2.90), and FLAIR-T2 ≥ 2,000 mm2 or ≥60 cm3 (HR 4.16, 3.93, and 3.72), respectively. Other variables including necrosis, tumor mass, necrosis/tumor ratio, and FLAIR/tumor ratio were not significantly correlated with OS. Conclusion: Our results reveal a high correlation among measurements of tumor size performed with the three methods. Pre-operative FLAIR-T2 hyperintensity area and volumes provided, independently of the measurement method, the optimal neuroimaging features predicting OS in primary glioblastoma patients, followed by age ≥ 65 years and MGMT methylation.

Orbital Radioiodine Uptake on Scintigraphy in a Patient with Thyroid Cancer.

Background: Orbital radioiodine uptake in patients with thyroid cancer is very uncommon with only a few reported cases, most of them being metastasis. The accumulation of 131I in nonthyroidal tissues and body fluids can lead to false-positive results in scintigraphy, which are sometimes difficult to differentiate from true metastases. Case Report: A post-therapy 131I whole-body (WBI) scintigraphy in an asymptomatic 57-year-old female with papillary thyroid carcinoma (PTC) previously treated with total thyroidectomy and 6 ablative radioiodine doses showed a focal uptake in the right eyeball region. The lesion, placed in the orbital space, was surgically removed, and histology revealed a conjunctival inclusion cyst. Discussion: Ocular and orbital metastases from thyroid cancer, as well as some non-neoplastic disorders or contamination, are possible causes for 131I uptake in the orbital region in scintigraphy. Conjunctival inclusion cyst is a condition associated with incidental 131I uptake that had not been reported before and should be ruled out as a non-metastatic cause of orbital radioiodine uptake in patients with PTC.

Prediction of postoperative lung function after major lung resection for lung cancer using volumetric computed tomography.

OBJECTIVES: The study objectives were to assess the accuracy of volumetric computed tomography to predict postoperative lung function in patients with lung cancer in relation to anatomic segments counting and perfusion scintigraphy, to generate specific predictive equations for each functional parameter, and to evaluate accuracy and precision of these in a validation cohort. METHODS: We assessed pulmonary functions preoperatively and 3 to 4 months postoperatively after lung resection for lung cancer (n = 114). Absolute and relative lung volumes (total and upper/middle/lower) were determined using volumetric software analysis for staging thoracic computed tomography scans. Predicted postoperative function was calculated by segments counting, scintigraphy, and volumetric computed tomography. RESULTS: Volumetric computed tomography achieves a higher correlation and precision with measured postoperative lung function than segments counting or scintigraphy (correlation and intraclass correlation coefficients, 0.779-0.969 and 0.776-0.969; 0.573-0.887 and 0.552-0.882; and 0.578-0.834 and 0.532-0.815, respectively), as well as greater accuracy, determined by narrower agreement coefficients for forced vital capacity, forced expiratory volume in 1 second, lung diffusing capacity, and peak oxygen uptake. After validation in an independent cohort (n = 43), adjusted linear regression including volumetric estimation of decreased postoperative ventilation for postoperative lung function parameters explains 98% to 99% of variance. CONCLUSIONS: Volumetric computed tomography is a reliable and accurate method to predict postoperative lung function in patients undergoing lung resection that provides better accuracy than conventional procedures. Because lung computed tomography is systematically performed in the staging of patients with suspected lung cancer, this volumetric analysis might simultaneously provide the information necessary to evaluate operability.

In Vivo 3D Analysis of Thoracic Kinematics: Changes in Size and Shape During Breathing and Their Implications for Respiratory Function in Recent Humans and Fossil Hominins.

The human ribcage expands and contracts during respiration as a result of the interaction between the morphology of the ribs, the costo-vertebral articulations and respiratory muscles. Variations in these factors are said to produce differences in the kinematics of the upper thorax and the lower thorax, but the extent and nature of any such differences and their functional implications have not yet been quantified. Applying geometric morphometrics we measured 402 three-dimensional (3D) landmarks and semilandmarks of 3D models built from computed tomographic scans of thoraces of 20 healthy adult subjects in maximal forced inspiration (FI) and expiration (FE). We addressed the hypothesis that upper and lower parts of the ribcage differ in kinematics and compared different models of functional compartmentalization. During inspiration the thorax superior to the level of the sixth ribs undergoes antero-posterior expansion that differs significantly from the medio-lateral expansion characteristic of the thorax below this level. This supports previous suggestions for dividing the thorax into a pulmonary and diaphragmatic part. While both compartments differed significantly in mean size and shape during FE and FI the size changes in the lower compartment were significantly larger. Additionally, for the same degree of kinematic shape change, the pulmonary thorax changes less in size than the diaphragmatic thorax. Therefore, variations in the form and function of the diaphragmatic thorax will have a strong impact on respiratory function. This has important implications for interpreting differences in thorax shape in terms of respiratory functional differences within and among recent humans and fossil hominins. Anat Rec, 300:255-264, 2017. © 2016 Wiley Periodicals, Inc.

Surgical management of brainstem-expanding lesions: the role of neuroimaging.

The brainstem is no longer regarded as an inoperable area, thanks to the huge advances that have been made in neurosurgery recently. Preoperative planning based on modern neuroimaging techniques (high-resolution magnetic resonance imaging and helical computed tomography) and advances in microneurosurgery and neuroanesthesia allows brainstem surgery to be performed with acceptable morbidity and mortality rates. Most surgically treated, space-occupying lesions in the brainstem are hematomas, and they are usually associated with cavernoma hemorrhage. However, over the last 25 years, there have also been reports from widely recognized neurosurgical centers on the positive clinical results of partial and even complete removal of brainstem tumors, mostly of glial origin. In this article, we focus on surgical planning based on neuroimaging techniques and its application for the surgical management of cavernomas, with or without hemorrhage, and focal and exophytic tumors. First of all, we review the indications for surgery of these lesions, until now almost always following imaging criteria, using the most surgically oriented classifications (especially in brainstem gliomas). In addition, we review the current controversy regarding the need for biopsy or if we can still manage them in base of imaging criteria. We also describe advances in the most significant imaging techniques in this field, emphasizing those in diffusion tensor imaging and neuronavigation. Finally, we present several cases to illustrate the role of neuroimaging in this field and to demonstrate the importance of neuroradiologists and neurosurgeons working together before and during the surgery.