Nigrosome 1 Detection at 3T MRI for the Diagnosis of Early-Stage Idiopathic Parkinson Disease: Assessment of Diagnostic Accuracy and Agreement on Imaging Asymmetry and Clinical Laterality

BACKGROUND AND PURPOSE

In the early stages of idiopathic Parkinson disease, motor symptoms are usually asymmetric. We aimed to assess the feasibility of nigrosome 1 detection at 3T MR imaging to analyze the agreement of its asymmetry and clinical laterality.

MATERIALS AND METHODS

High-resolution 3D multiecho imaging was performed at 3T MR imaging in 13 healthy subjects and 24 patients with idiopathic Parkinson disease confirmed by N-3-fluoropropyl-2-β-carbomethoxy-3-β-(4-iodophenyl) nortropane ((18)F-FP-CIT) PET. The nigrosome 1 detection findings by using the MR imaging data were rated as "normal," "possibly abnormal," and "abnormal" by 2 independent reviewers. The degree of (18)F-FP-CIT binding was visually assessed in the caudate nucleus and putamen on PET images. Clinical laterality was evaluated by scores of the Unified Parkinson Disease Rating Scale, Part III. Asymmetry of the affected nigrosome 1 and the degree of (18)F-FP-CIT binding were analyzed for agreement with clinical laterality.

RESULTS

The diagnostic sensitivity, specificity, and accuracy of the nigrosome 1 detection at 3T MR imaging was 100%, 84.6%, and 94.6%, respectively. Interrater agreements for the abnormality and asymmetry of nigrosome 1 were excellent (κ = 0.863 and 0.835, respectively). In patients with idiopathic Parkinson disease, the agreement of asymmetry between clinical laterality and nigrosome 1 detection was good (κ = 0.724). The degree of the (18)F-FP-CIT PET binding showed fair agreement (κ = 0.235) with clinical laterality.

CONCLUSIONS

The abnormality involving nigrosome 1 can be detected at 3T MR imaging with an accuracy of 94.6%. The clinical laterality is in high concordance with the laterality of the nigrosome 1 detection at 3T (κ = 0.724).

Cortical thickness and hippocampal shape in pure vascular mild cognitive impairment and dementia of subcortical type

BACKGROUND AND PURPOSE

The progression pattern of brain structural changes in patients with isolated cerebrovascular disease (CVD) remains unclear. To investigate the role of isolated CVD in cognitive impairment patients, patterns of cortical thinning and hippocampal atrophy in pure subcortical vascular mild cognitive impairment (svMCI) and pure subcortical vascular dementia (SVaD) patients were characterized.

METHODS

Forty-five patients with svMCI and 46 patients with SVaD who were negative on Pittsburgh compound B (PiB) positron emission tomography imaging and 75 individuals with normal cognition (NC) were recruited.

RESULTS

Compared with NC, patients with PiB(-) svMCI exhibited frontal, language and retrieval type memory dysfunctions, which in patients with PiB(-) SVaD were further impaired and accompanied by visuospatial and recognition memory dysfunctions. Compared with NC, patients with PiB(-) svMCI exhibited cortical thinning in the frontal, perisylvian, basal temporal and posterior cingulate regions. This atrophy was more prominent and extended further toward the lateral parietal and medial temporal regions in patients with PiB(-) SVaD. Compared with NC subjects, patients with PiB(-) svMCI exhibited hippocampal shape deformities in the lateral body, whilst patients with PiB(-) SVaD exhibited additional deformities within the lateral head and inferior body.

CONCLUSIONS

Our findings suggest that patients with CVD in the absence of Alzheimer's disease pathology can be demented, showing cognitive impairment in multiple domains, which is consistent with the topography of cortical thinning and hippocampal shape deformity.

Endoscopic add-on stiffness probe for real-time soft surface characterisation in MIS

This paper explores a novel stiffness sensor which is mounted on the tip of a laparoscopic camera. The proposed device is able to compute stiffness when interacting with soft surfaces. The sensor can be used in Minimally Invasive Surgery, for instance, to localise tumor tissue which commonly has a higher stiffness when compared to healthy tissue. The purely mechanical sensor structure utilizes the functionality of an endoscopic camera to the maximum by visually analyzing the behavior of trackers within the field of view. Two pairs of spheres (used as easily identifiable features in the camera images) are connected to two springs with known but different spring constants. Four individual indenters attached to the spheres are used to palpate the surface. During palpation, the spheres move linearly towards the objective lens (i.e. the distance between lens and spheres is changing) resulting in variations of their diameters in the camera images. Relating the measured diameters to the different spring constants, a developed mathematical model is able to determine the surface stiffness in real-time. Tests were performed using a surgical endoscope to palpate silicon phantoms presenting different stiffness. Results show that the accuracy of the sensing system developed increases with the softness of the examined tissue.

Influence of Cinnamon on Glycemic Control in Individuals With Prediabetes: A Randomized Controlled Trial

Context

The identification of adjunct safe, durable, and cost-effective approaches to reduce the progression from prediabetes to type 2 diabetes (T2D) is a clinically relevant, unmet goal. It is unknown whether cinnamon’s glucose-lowering properties can be leveraged in individuals with prediabetes.

Objective

The objective of this work is to investigate the effects of cinnamon on measures of glucose homeostasis in prediabetes.

Design, Setting, Participants, and Intervention

This double-blind, placebo-controlled, clinical trial randomly assigned adult individuals meeting any criteria for prediabetes to receive cinnamon 500 mg or placebo thrice daily (n = 27/group). Participants were enrolled and followed at 2 academic centers for 12 weeks.

Main Outcome Measures

Primary outcome was the between-group difference in fasting plasma glucose (FPG) at 12 weeks from baseline. Secondary end points included the change in 2-hour PG of the oral glucose tolerance test (OGTT), and the change in the PG area under the curve (AUC) derived from the OGTT.

Results

From a similar baseline, FPG rose after 12 weeks with placebo but remained stable with cinnamon, leading to a mean between-group difference of 5 mg/dL (P < .05). When compared to the respective baseline, cinnamon, but not placebo, resulted in a significant decrease of the AUC PG (P < .001) and of the 2-hour PG of the OGTT (P < .05). There were no serious adverse events in either study group.

Conclusions

In individuals with prediabetes, 12 weeks of cinnamon supplementation improved FPG and glucose tolerance, with a favorable safety profile. Longer and larger studies should address cinnamon’s effects on the rate of progression from prediabetes to T2D.

Extended approach or usage of nasoseptal flap is a risk factor for olfactory dysfunction after endoscopic anterior skullbase surgery: results from 928 patients in a single tertiary center

BACKGROUND

The aim of this study was to compare olfactory function change in patients who underwent endoscopic skull-base surgery.

METHODOLOGY

A total of 928 patients were included in this retrospective study. Olfactory function was measured using the non- validated Likert scale (0â€"100), the Cross-Cultural Smell Identification Test (CC-SIT) and the butanol threshold test (BTT). Patients were divided into two groups: an endoscopic trans-sellar approach group (ETA, n = 768) and an extended endoscopic endonasal approach group (EEEA, n = 160). The ETA group was sub-divided into Nasoseptal flap (NSF) and no NSF groups.

RESULTS

Non-validated olfactory function significantly worsened in the EEEA and ETA-NSF groups compared with that in the ETA- no NSF group for at least 6 months post-operatively. Validated olfactory impairment (BTT and CC-SIT) was also significantly worse in the EEEA and NSF groups compared with that in the ETA-no NSF group 3 months post-operatively. Additionally, the degrees of non-validated and validated olfactory deterioration were not significantly different between the EEEA and ETA-NSF groups. We also found that CC-SIT score changes were significantly impaired in tuberculum sellae meningioma patients than in craniopharyn- gioma patients.

CONCLUSIONS

We conclude that NSF was the key factor that led to olfactory impairment after endoscopic skull-base surgery.

Vertically-resolved profiles of mass concentrations and particle backscatter coefficients of Asian dust plumes derived from lidar observations of silicon dioxide

This study presents a method to retrieve vertically-resolved profiles of dust mass concentrations by analyzing Raman lidar signals of silicon dioxide (quartz) at 546nm. The observed particle plumes consisted of mixtures of East Asian dust with anthropogenic pollution. Our method for the first time allows for extracting the contribution of the aerosol component "pure dust" contained in the aerosol type "polluted dust". We also propose a method that uses OPAC (Optical Properties of Aerosols and Clouds) and the mass concentrations profiles of dust in order to derive profiles of backscatter coefficients of pure dust in mixed dust/pollution plumes. The mass concentration of silicon dioxide (quartz) in the atmosphere can be estimated from the backscatter coefficient of quartz. The mass concentration of dust is estimated by the weight percentage (38-77%) of mineral quartz in Asian dust. The retrieved dust mass concentrations are classified into water soluble, nucleation, accumulation, mineral-transported and coarse mode according to OPAC. The mass mixing ratio of 0.018, 0.033, 0.747, 0.130 and 0.072, respectively, is used. Dust extinction coefficients at 550nm were calculated by using OPAC and prescribed number concentrations for each of the 5 components. Dust backscatter coefficients were calculated from the dust extinction coefficients on the basis of a lidar ratio of 45±3sr at 532nm. We present results of quartz-Raman measurements carried out on the campus of the Gwangju Institute of Science and Technology (35.10°N, 126.53°E) on 15, 16, and 21 March 2010.

Comfort and learnability assessment of a new soft robotic manipulator for minimally invasive surgery

Laparoscopic surgeons perform precise and time consuming procedures while holding awkward poses in their upper body and arms. There is an ongoing effort to produce robotic tools for laparoscopic surgery that will simplify these tasks and reduce risk of errors to help both the surgeon and the patient. STIFF-FLOP is an ongoing EU FP7 project focusing on this by creating a stiffness controllable soft robotic manipulator. This paper reports on a study to test the soft manipulator's learnability and the effort associated with its use. The tests involved a limited prototype of the manipulator with a custom built test rig and EMG acquisition system. Task times and video recordings along with EMG waveforms from the forearm muscles of participants (n=25) were measured for objective assessment. A questionnaire was also provided to the participants for subjective assessment. The data shows that in average EMG levels were 25.9% less in RMS when using the STIFF-FLOP arm than when conventional laparoscopic tools were used. In terms of learnability, from the first to the second attempt on the STIFF-FLOP manipulator, elapsed time was reduced by an average of 32.1%. Further details and analysis of the EMG signals as well as time and questionnaire results is presented in the paper.

Estimation of surface-level PM concentration from satellite observation taking into account the aerosol vertical profiles and hygroscopicity

Surface-level PM10 distribution was estimated from the satellite aerosol optical depth (AOD) products, taking the account of vertical profiles and hygroscopicity of aerosols over Jeju, Korea during March 2008 and October 2009. In this study, MODIS AOD data from the Terra and Aqua satellites were corrected with aerosol extinction profiles and relative humidity data. PBLH (Planetary Boundary Layer Height) was determined from MPLNET lidar-derived aerosol extinction coefficient profiles. Through statistical analysis, better agreement in correlation (R = 0.82) between the hourly PM10 concentration and hourly average Sunphotometer AOD was the obtained when vertical fraction method (VFM) considering Haze Layer Height (HLH) and hygroscopic growth factor f(RH) was used. The validity of the derived relationship between satellite AOD and surface PM10 concentration clearly demonstrates that satellite AOD data can be utilized for remote sensing of spatial distribution of regional PM10 concentration.

Biomechanical evaluation of the phases during simulated endotracheal intubation (ETI): pilot study on the effect of different laryngoscopes

Endotracheal Intubation (ETI) is a common airway procedure used to connect the larynx and the lungs through a windpipe in patients under emergency situations. The process is carried out by a laryngoscope inserted into the mouth, used to help doctors in visualizing the glottis and inserting the tube. Currently, very few studies on objective evaluation of the biomechanics of the doctors during the procedure have been done. Additionally, these studies have been concentrated only on the overall performance analysis, without any segmentation, with a consequent loss of important information. In this paper, the authors present a preliminary study on a methodology to objectively evaluate and segment the biomechanical performance of doctors during the ETI, using surface electromyography and inertial measurement units. In particular, the validation has been performed by comparing three kinds of laryngoscopes involving an expert doctor. Finally, results are presented and commented.

Optical and geometric property classification of natural aerosol types with a large open chamber system and multi-wavelength elastic polarized LiDAR

Natural aerosols, originating from uncontrollable processes, are widely distributed and often interfere with the remote sensing of anthropogenic aerosols. This interference occurs because distinguishing between particle types is challenging when they coexist. Despite their significant impact on radiative forcing and climate, research on natural aerosols remains limited due to their unpredictable nature. To address this, we implemented a pilot-scale open chamber system coupled with multi-wavelength elastic polarized LiDAR. This system enables the separation of target particles from ambient aerosols, enabling the development of a specialized analysis algorithm that calculates optical parameters-such as the Ångström Exponent (AE) and depolarization ratio (δ)- which serve as unique "fingerprints" for distinguishing aerosol types. Our experiments included some natural particles, such as yeast, whey protein, fly ash, flour, pine tree pollen, and kaolinite. Distinct optical properties were observed, with yeast exhibiting high δ values at 532 nm (0.31 ± 0.09) and 1064 nm (0.06 ± 0.01). Whey protein and fly ash were distinguishable based on AE values of -0.23 ± 1.16 and 0.31 ± 0.59, respectively. Pollen, another key natural aerosol, showed δ values of 0.33 ± 0.03 at 532 nm and 0.04 ± 0.01 at 1064 nm, enabling clear differentiation from other aerosol types. By incorporating infrared wavelengths into our LiDAR system, we enhanced the accuracy of aerosol characterization. This study highlights the approach for distinguishing natural aerosols and lays the groundwork for continuous monitoring systems to understand their atmospheric and climatic impacts better.

Lidar sprectroscopy instrument (LISSI): An infrastructure facility for chemical aerosol profiling at the University of Hertfordshire

The lidar development at the University of Hertfordshire explores the feasibility of using Raman backscattering for chemical aerosol profiling. This paper provides an overview of the new facility. A high-power Nd:YAG/OPO setup is used to excite Raman backscattering at a wide range of wavelengths. The receiver combines a spectrometer with a 32-channel detector or an ICCD camera to resolve Raman signals of various chemical compounds.

The new facility will open new avenues for chemical profiling of aerosol pollution from measurements of Raman scattering by selected chemical compounds, provide data that allow to close the gap between optical and microphysical aerosol profiling with lidar and enables connecting lidar measurements to parameters used in atmospheric modelling.