Clinical Super-Resolution Computed Tomography of Bone Microstructure: Application in Musculoskeletal and Dental Imaging.

Purpose: Clinical cone-beam computed tomography (CBCT) devices are limited to imaging features of half a millimeter in size and cannot quantify the tissue microstructure. We demonstrate a robust deep-learning method for enhancing clinical CT images, only requiring a limited set of easy-to-acquire training data.

Methods: Knee tissue from five cadavers and six total knee replacement patients, and 14 teeth from eight patients were scanned using laboratory CT as training data for the developed super-resolution (SR) technique.

Automated analysis of rabbit knee calcified cartilage morphology using micro-computed tomography and deep learning.

Structural dynamics of calcified cartilage (CC) are poorly understood. Conventionally, CC structure is analyzed using histological sections. Micro-computed tomography (µCT) allows for three-dimensional (3D) imaging of mineralized tissues; however, the segmentation between bone and mineralized cartilage is challenging.

Bilateral Motor Responses to Transcranial Magnetic Stimulation in Preterm Children at 9 Years of Age.

Objective: This study was aimed to evaluate motor tracts integrity in nondisabled preterm-born (PT) children at 9 years of age.

Methods: Overall, 18 PT and 13 term-born (T) children without motor disability were assessed by transcranial magnetic stimulation (TMS). Motor-evoked potentials (MEPs) were measured bilaterally from the abductor pollicis brevis (APB) and the tibialis anterior (TA) muscles.

Automating three-dimensional osteoarthritis histopathological grading of human osteochondral tissue using machine learning on contrast-enhanced micro-computed tomography.

Objective: To develop and validate a machine learning (ML) approach for automatic three-dimensional (3D) histopathological grading of osteochondral samples imaged with contrast-enhanced micro-computed tomography (CEμCT).

Design: A total of 79 osteochondral cores from 24 total knee arthroplasty patients and two asymptomatic donors were imaged using CEμCT with phosphotungstic acid -staining. Volumes-of-interest (VOI) in surface (SZ), deep (DZ) and calcified (CZ) zones were extracted depth-wise and subjected to dimensionally reduced Local Binary Pattern -textural feature analysis.

Quantifying Subresolution 3D Morphology of Bone with Clinical Computed Tomography.

The aim of this study was to quantify sub-resolution trabecular bone morphometrics, which are also related to osteoarthritis (OA), from clinical resolution cone beam computed tomography (CBCT). Samples (n = 53) were harvested from human tibiae (N = 4) and femora (N = 7). Grey-level co-occurrence matrix (GLCM) texture and histogram-based parameters were calculated from CBCT imaged trabecular bone data, and compared with the morphometric parameters quantified from micro-computed tomography.

Spectral entropy indicates electrophysiological and hemodynamic changes in drug-resistant epilepsy - A multimodal MREG study.

Objective: Epilepsy causes measurable irregularity over a range of brain signal frequencies, as well as autonomic nervous system functions that modulate heart and respiratory rate variability. Imaging dynamic neuronal signals utilizing simultaneously acquired ultra-fast 10 Hz magnetic resonance encephalography (MREG), direct current electroencephalography (DC-EEG), and near-infrared spectroscopy (NIRS) can provide a more comprehensive picture of human brain function. Spectral entropy (SE) is a nonlinear method to summarize signal power irregularity over measured frequencies.

Altered physiological brain variation in drug-resistant epilepsy.

Introduction: Functional magnetic resonance imaging (fMRI) combined with simultaneous electroencephalography (EEG-fMRI) has become a major tool in mapping epilepsy sources. In the absence of detectable epileptiform activity, the resting state fMRI may still detect changes in the blood oxygen level-dependent signal, suggesting intrinsic alterations in the underlying brain physiology.

Methods: In this study, we used coefficient of variation (CV) of critically sampled 10 Hz ultra-fast fMRI (magnetoencephalography, MREG) signal to compare physiological variance between healthy controls (n = 10) and patients (n = 10) with drug-resistant epilepsy (DRE).

Fluctuations of the EEG-fMRI correlation reflect intrinsic strength of functional connectivity in default mode network.

Both functional magnetic resonance imaging (fMRI) and electrophysiological recordings have revealed that resting-state functional connectivity is temporally variable in human brain. Combined full-band electroencephalography-fMRI (fbEEG-fMRI) studies have shown that infraslow (<.1 Hz) fluctuations in EEG scalp potential are correlated with the blood-oxygen-level-dependent (BOLD) fMRI signals and that also this correlation appears variable over time.

Epileptiform and periodic EEG activities induced by rapid sevoflurane anaesthesia induction.

Objectives: The aim of the study was to compare the EEG findings and haemodynamic parameters of adult male patients while undergoing mask induction with sevoflurane anaesthesia with either controlled hyperventilation (CH) or spontaneous breathing (SB).

Methods: Twenty male patients, aged 23-52 (mean 42) years were anaesthetized randomly with either spontaneous breathing or mild controlled hyperventilation via mask. EEG was recorded using a full 10-20 electrode set.

Riboflavin-Responsive Multiple Acyl-CoA Dehydrogenase Deficiency Associated with Hepatoencephalomyopathy and White Matter Signal Abnormalities on Brain MRI.

Multiple acyl-CoA dehydrogenase deficiency (MADD) is a rare inborn error of metabolism affecting both fatty acid and amino acid oxidation. It can manifest at any age, but riboflavin-responsiveness has mainly been described in less severely affected patients. We describe an infant with severe MADD presenting with profound hypotonia and hepatomegaly.

Real-time monitoring of human blood-brain barrier disruption.

Chemotherapy aided by opening of the blood-brain barrier with intra-arterial infusion of hyperosmolar mannitol improves the outcome in primary central nervous system lymphoma. Proper opening of the blood-brain barrier is crucial for the treatment, yet there are no means available for its real-time monitoring. The intact blood-brain barrier maintains a mV-level electrical potential difference between blood and brain tissue, giving rise to a measurable electrical signal at the scalp.

Reading, listening and memory-related brain activity in children with early-stage temporal lobe epilepsy of unknown cause-an fMRI study.

Background And Aims: The changes in functional brain organization associated with paediatric epilepsy are largely unknown. Since children with epilepsy are at risk of developing learning difficulties even before or shortly after the onset of epilepsy, we assessed the functional organization of memory and language in paediatric patients with temporal lobe epilepsy (TLE) at an early stage in epilepsy.

Methods: Functional magnetic resonance imaging was used to measure the blood oxygenation level-dependent (BOLD) response to four cognitive tasks measuring reading, story listening, memory encoding and retrieval in a population-based group of children with TLE of unknown cause (n = 21) and of normal intelligence and a healthy age and gender-matched control group (n = 21).

Neuropsychological performance in children with temporal lobe epilepsy having normal MRI findings.

Background And Aims: Most information on the neuropsychological performance of pediatric patients with temporal lobe epilepsy (TLE) is derived from selected surgical series. Non-lesional pediatric TLE patients were studied here at the population level in order to investigate the extent to which neuropsychological deficits predisposing to learning difficulties exist in this more common group.

Methods: Language, memory and executive functions were measured in children aged 8-15 years with non-lesional TLE and of normal intelligence (n = 21), and their performance was compared with that of healthy age and gender-matched children (n = 21).

Signs of general inflammation and kidney function are associated with the ocular features of acute Puumala hantavirus infection.

Background: Puumala hantavirus (PUUV) causes nephropathia epidemica (NE), a type of viral haemorrhagic fever with renal syndrome (HFRS). This febrile infection may affect the kidneys, central nervous system (CNS), and the eye. Acute illness is associated with increased tissue permeability and tissue oedema, and many patients experience reduced vision.

Lambert-Eaton myasthenic syndrome following H1N1-influenza vaccination: a case report.

Background: The outbreak of influenza A (H1N1) pandemic during the year 2009 led to the development of several vaccinations against H1N1 virus. In Finland, 2.6 million citizens were vaccinated during pandemic 2009 - 2010 with adjuvanted influenza vaccine, Pandemrix(®) .

Connectivity disruptions in resting-state functional brain networks in children with temporal lobe epilepsy.

Functional resting-state connectivity has been shown to be altered in certain adult epilepsy populations, but few connectivity studies have been performed on pediatric epilepsy patients. Here functional connectivity was measured in pediatric, non-lesional temporal lobe epilepsy patients with normal intelligence and compared with that in age and gender-matched healthy controls using the independent component analysis method. We hypothesized that children with non-lesional temporal lobe epilepsy have disrupted functional connectivity within resting-state networks.

Young male patients are at elevated risk of developing serious central nervous system complications during acute Puumala hantavirus infection.

Background: Our aim was to characterize clinical properties and laboratory parameters in patients with or without cerebrospinal fluid (CSF) findings suggestive of central nervous system (CNS) involvement, and especially those who developed serious CNS complications during acute nephropathia epidemica (NE) caused by Puumala hantavirus (PUUV) infection.

Methods: A prospective cohort of 40 patients with acute NE and no signs of major CNS complications was analyzed. In addition, 8 patients with major CNS complications associated with NE were characterized.

Alterations in regional homogeneity of baseline brain activity in pediatric temporal lobe epilepsy.

Recent findings on intracortical EEG measurements show that the synchrony of localized neuronal networks is altered in epileptogenesis, leading to generalized seizure activity via connector hubs in the neuronal networks. Regional homogeneity (ReHo) analysis of blood oxygen level-dependent (BOLD) signals has demonstrated localized signal synchrony and disease-related alterations in a number of instances. We wanted to find out whether the ReHo of resting-state activity can be used to detect regional signal synchrony alterations in children with non-lesional temporal lobe epilepsy (TLE).

Atypical perceptual narrowing in prematurely born infants is associated with compromised language acquisition at 2 years of age.

Background: Early auditory experiences are a prerequisite for speech and language acquisition. In healthy children, phoneme discrimination abilities improve for native and degrade for unfamiliar, socially irrelevant phoneme contrasts between 6 and 12 months of age as the brain tunes itself to, and specializes in the native spoken language. This process is known as perceptual narrowing, and has been found to predict normal native language acquisition.

Central nervous system-related symptoms and findings are common in acute Puumala hantavirus infection.

Background: Puumala hantavirus (PUUV) causes a hemorrhagic fever with renal syndrome (HFRS) also called nephropathia epidemica (NE). Recent case reports and retrospective studies suggest that NE may damage the pituitary gland. Based on these observations, our goal was to explore the nature of this complication prospectively.

Processing of affective speech prosody is impaired in Asperger syndrome.

Many people with the diagnosis of Asperger syndrome (AS) show poorly developed skills in understanding emotional messages. The present study addressed discrimination of speech prosody in children with AS at neurophysiological level. Detection of affective prosody was investigated in one-word utterances as indexed by the N1 and the mismatch negativity (MMN) of auditory event-related potentials (ERPs).

Stretch- and H-reflexes of the lower leg during whole body cooling and local warming.

Background: This study was undertaken to evaluate if possible changes in stretch- and H-reflexes could be related to the changes in the EMG activity of the cooled lower leg muscles observed during a stretch-shortening cycle exercise.

Methods: Eight subjects wearing shorts and jogging shoes were exposed once to 27 degrees C and twice to 10 degrees C for 60 min each. During the second exposure to 10 degrees C, the subject's lower legs were kept warm (10 degrees Clw) with electrical pillows.

Tibial nerve somatosensory evoked potentials during EEG suppression in sevoflurane anaesthesia.

Objectives And Methods: Cortical tibial nerve somatosensory evoked potentials (TSEPs) were recorded from 10 subjects in sevoflurane anaesthesia in order to study TSEP during EEG suppression.

Results: With a stimulation frequency less than one per second the major component was a positive wave which had maximal amplitude parietally ipsilaterally to stimulus and mean latency of 46.1 ms.

Single-sweep cortical somatosensory evoked potentials: N20 and evoked bursts in sevoflurane anaesthesia.

Cortical evoked responses to median nerve stimulation were recorded from 21 subjects during sevoflurane anaesthesia at the level of burst suppression in EEG. The N20/P22 wave had the typical form of a negative wave postcentrally, and positive precentrally. The amplitude exceeded 4 microV in all patients, making it easily visible without averaging on the low-amplitude suppression.