High Signal Intensity Research Articles

N-Terminal chemical derivatization of peptides with 4-formyl-benzenesulfonic acid and electrospray positive and negative tandem mass spectrometry with high abundance of b-ion series.

Selective derivatization of peptide N-terminus with 4-formyl-benzenesulfonic acid (FBSA) enables chemically activated fragmentation in positive and negative ion modes (ESI+/-) under charge reduction conditions. Overlapped positive and negative tandem mass spectra show b-ions making the assignment of b-ion series fragments easy and accurate. We developed an FBSA-peptide microwave-assisted derivatization procedure. Derivatized and nonderivatized bovine serum albumin tryptic peptides and insulin non-tryptic peptide were compared after tandem mass spectrometry (MS/MS) analysis in positive and negative ion modes. A high-quality data set of sulfonated b-ions obtained in negative tandem mass spectra of singly charged FBSA-peptides were matched to detected b-ions in positive MS/MS spectra. Moreover, negative spectra signals were converted and matched against y-ions in positive tandem mass spectra to identify complete peptide sequences. The FBSA derivatization procedure produced a significantly improved MS/MS data set (populated by high-intensity signals of b- and y-ions) compared to commonly used N-terminal sulfonation reagents. Undesired side reactions almost do not occur, and the procedure reduces the derivatization time. It was found that b-ion intensities comprise 15% and 13% compared to combined ion intensities generated in positive- and negative ion modes, respectively. High visibility of b-ion series in negative ion mode can be attributed to N-terminal sulfonation that had no negative effect on the production of b- and y-ion series in positive ion mode. The FBSA derivatization and de novo sequencing approach outlined here is a reliable method for accurate peptide sequence assignment. Increased production of b-ions in positive- and negative ion modes greatly improves peak assignment and thus enables accurate sequence reconstruction. Implementation of the named methodology would improve the quality of de novo sequencing data and reduce the number of misinterpreted spectra.

Estimation of brain tissue response by electrical stimulation in a subject-specific model implemented by conductivity tensor imaging.

Electrical stimulation such as transcranial direct current stimulation (tDCS) is widely used to treat neuropsychiatric diseases and neurological disorders. Computational modeling is an important approach to understand the mechanisms underlying tDCS and optimize treatment planning. When applying computational modeling to treatment planning, uncertainties exist due to insufficient conductivity information inside the brain. In this feasibility study, we performed in vivo MR-based conductivity tensor imaging (CTI) experiments on the entire brain to precisely estimate the tissue response to the electrical stimulation. A recent CTI method was applied to obtain low-frequency conductivity tensor images. Subject-specific three-dimensional finite element models (FEMs) of the head were implemented by segmenting anatomical MR images and integrating a conductivity tensor distribution. The electric field and current density of brain tissues following electrical stimulation were calculated using a conductivity tensor-based model and compared to results using an isotropic conductivity model from literature values. The current density by the conductivity tensor was different from the isotropic conductivity model, with an average relative difference |rD| of 52 to 73%, respectively, across two normal volunteers. When applied to two tDCS electrode montages of C3-FP2 and F4-F3, the current density showed a focused distribution with high signal intensity which is consistent with the current flowing from the anode to the cathode electrodes through the white matter. The gray matter tended to carry larger amounts of current densities regardless of directional information. We suggest this CTI-based subject-specific model can provide detailed information on tissue responses for personalized tDCS treatment planning.

Bilateral tonic-clonic seizure and focal cortical hyperexcitability in familial Creutzfeldt-Jakob disease with E200K mutation of the prion protein.

Convulsive epileptic seizures are rare in Creutzfeldt-Jakob disease (CJD) and their clinical and EEG features have not been reported in detail. We describe a case of familial CJD with an E200K mutation of the prion protein who presented with bilateral tonic-clonic seizures (BTCS) during long-term video-EEG monitoring. Semiologically, BTCS showed focal clinical signs such as head turning and eye deviation to the left. The ictal EEG started with generalized polyspikes. Interictal EEG showed generalized periodic discharges with right fronto-temporal predominance (larger amplitude and earlier onset compared with other regions). MRI showed high-intensity signals persistently in the right temporo-parietal region on diffusion-weighted images (DWI). Interictal single-photon emission computed tomography (SPECT) showed hyperperfusion in the same region. Brain pathology revealed typical spongiform changes in CJD without other pathological findings of rapidly progressive dementia. Our case demonstrates that CJD can cause BTCS with generalized EEG changes and focal semiological/imaging abnormalities, suggesting that diffuse cortical and subcortical epileptic networks may develop in familial CJD.

P398 ACUTE PERICARDITIS COMPLICATED BY RAPID DEVELOPMENT OF CONSTRICTION: A CASE REPORT

Abstract A 57–years–old man with no previous cardiovascular history presented with fever, hypotension, dyspnoea at rest and chest pain. The electrocardiogram showed sinus tachycardia, PR–segment depression and diffuse concave–upwards ST–segment elevation. Elevated C–reactive protein and low pro–BNP level were found at lab tests, procalcitonin and troponin were negative. Chest X–ray showed bilateral pleural effusion. Transthoracic echocardiogram (TTE) revealed mild–to–moderate serofibrinous pericardial effusion with initial diastolic collapse of right chambers, suggesting cardiac pre–tamponade. Because of the exiguity of liquid component, pericardiocentesis was not performed, patient was stabilized by fluid–challenge with hypertonic solution. Ibuprofen and colchicine were started. Left thoracentesis was performed removing one liter of fluid overall compatible with transudate. Cytological and microbiological examinations were negative. Despite of initial clinical improvement, the patient showed kidney failure and worsening of lung failure; perianal abscess was detected causing sepsis and requiring surgical drainage and antibiotic therapy with vancomycin and piperacillin/tazobactam. Culture exams were negative. After ibuprofen replacement with indomethacin a repeated TTE showed reduced pericardial effusion, but also respiratory variation in ventricular filling with signs of interventricular dependence. Cardiac magnetic resonance showed thickening and high signal intensity of pericardial layers on T2 weighted imaging and ventricular septal shift on free–breathing cine sequences, suggesting effusive–constrictive pericarditis. Left and right cardiac catheterization demonstrated ventricular “dip and plateau” pattern and ventricular discordance. Considering the lack of clinical improvement on medical therapy, off–bypass pericardiectomy was performed. Incomplete adhesion between the two pericardial layers and thick gelatinous material were found. After surgery patient experienced rapid clinical improvement; cardiac index increased from 1.5 to 3.5 L/min/m2. Effusive–constrictive pericarditis is a rare and dreaded complication of acute pericarditis. Surgery, when appropriated, is crucial for prognosis. In our case initial response to anti–inflammatory therapy with reduced pericardial effusion unmasked constrictive physiology in an effusive–constrictive pericarditis. Clinical management was complicated by sepsis which could have played a role in constriction developing.

Ultrashort time-to-echo MR morphology of cartilaginous endplate correlates with disc degeneration in the lumbar spine.

Using ultrashort echo time (UTE) MRI, we determined prevalence of abnormal cartilaginous endplate (CEP), and the relationship between CEP and disc degeneration in human lumbar spines. Lumbar spines from 71 cadavers (age 14-74years) were imaged at 3T using sagittal UTE and spin echo T2 map sequences. On UTE images, CEP morphology was defined as "normal" with linear high signal intensity or "abnormal" with focal signal loss and/or irregularity. On spin echo images, disc grade and T2 values of the nucleus pulposus (NP) and annulus fibrosus (AF) were determined. 547 CEPs and 284 discs were analysed. Effects of age, sex, and level on CEP morphology, disc grade, and T2 values were determined. Effects of CEP abnormality on disc grade, T2 of NP, and T2 of AF were also determined. Overall prevalence of CEP abnormality was 33% and it tended to increase with older ages (p = 0.08) and at lower spinal levels of L5 than L2 or L3 (p = 0.001). Disc grades were higher and T2 values of the NP were lower in older spines (p < 0.001) and at lower disc level of L4-5 (p < 0.05). We found significant association between CEP and disc degeneration; discs adjacent to abnormal CEPs had high grades (p < 0.01) and lower T2 values of the NP (p < 0.05). These results suggest that abnormal CEPs are frequently found, and it associates significantly with disc degeneration, suggesting an insight into pathoetiology of disc degeneration.

Optic Nerve Ischemia Secondary to Pediatric Orbital Cellulitis.

FIG. 1FIG. 2Diffusion-weighted imaging (DWI) is a specific sequence of magnetic resonance imaging (MRI) that estimates the rate of water diffusion. The apparent diffusion coefficient (ADC) image, on its turn, is a form of quantifying the diffusion of water in DWI. Obstacles to water diffusion include cellularity and ischemia, which are seen with high signal intensity in DWI and low signal intensity in ADC. We describe the case of an 11-year-old boy who presented with left rapid-evolving cellulitis and globe tenting (Fig. 1A, massive left hemifacial and eyelid edema; Fig. 1B, axial computed tomography scan) that resulted in complete visual loss even after urgent cantholysis and drainage of a circumferential orbital abscess (Fig. 1C). On the first postoperative day, DWI (Fig. 2A) and ADC (Fig. 2B; optic nerves ADC values: right 1.034 s/mm2, left: 0.63 s/mm2) showed restricted diffusion along the entire extension of the left optic nerve (ON) indicating ischemia. The authors believe that the optic nerve ischemia resulted from the compression of the optic nerve pial vessels by the acute orbital compartment syndrome. Orbital hypertension also compressed the short posterior ciliary arteries and central retinal artery causing retinal and choroidal ischemia (Fig. 2C,D; optical coherence tomography: edema and complete disorganization of retinal layers). This case highlights that optic nerve ischemia is a mechanism of visual loss in orbital compartment syndromes.

Chemical Imaging of Pharmaceuticals in Biofilms for Wastewater Treatment Using Secondary Ion Mass Spectrometry.

The occurrence of pharmaceuticals in the aquatic environment is a global water quality challenge for several reasons, such as deleterious effects on ecological and human health, antibiotic resistance development, and endocrine-disrupting effects on aquatic organisms. To optimize their removal from the water cycle, understanding the processes during biological wastewater treatment is crucial. Time-of-flight secondary ion mass spectrometry imaging was successfully applied to investigate and analyze the distribution of pharmaceuticals as well as endogenous molecules in the complex biological matrix of biofilms for wastewater treatment. Several compounds and their localization were identified in the biofilm section, including citalopram, ketoconazole, ketoconazole transformation products, and sertraline. The images revealed the pharmaceuticals gathered in distinct sites of the biofilm matrix. While citalopram penetrated the biofilm deeply, sertraline remained confined in its outer layer. Both pharmaceuticals seemed to mainly colocalize with phosphocholine lipids. Ketoconazole concentrated in small areas with high signal intensity. The approach outlined here presents a powerful strategy for visualizing the chemical composition of biofilms for wastewater treatment and demonstrates its promising utility for elucidating the mechanisms behind pharmaceutical and antimicrobial removal in biological wastewater treatment.

Phase-space tomography in magnetically confined plasmas

In this paper, a tomography approach aiming at reconstructing a phase-space structure is proposed. For the phase-space resolved diagnostic system, a signal must be decomposed in real-space, velocity-space, and time; therefore, it is challenging to obtain a sufficiently high signal intensity in a single detector bin. To overcome this difficulty, three different sets of data having different integration directions in real-space, velocity-space, and time are simultaneously used, and a reconstruction of the original structure in the phase-space is attempted by a tomographic manner. The proposed method is demonstrated using a synthetic dataset in the actual diagnostic setup in the Large Helical Device. Time evolution of a phase-space perturbation induced by the Landau damping, which is caused by energetic particle-driven magnetohydrodynamic bursts, is successfully reconstructed by this method. Robustness against realistic diagnostic noise is also presented.

MRI characteristics of lumbosacral dural arteriovenous fistulas.

Spinal dural arteriovenous fistulas located in the lumbosacral region are rare and present with nonspecific clinical signs. The purpose of this study was to find out the specific radiologic features of these fistulas. We retrospectively reviewed the clinical and radiological data of 38 patients diagnosed with lumbosacral spinal dural arteriovenous fistulas in our institution from September 2016 to September 2021. All patients underwent time-resolved contrast-enhanced three-dimensional MRA and DSA examinations, and were treated with either endovascular or neurosurgical strategies. Most of the patients (89.5%) had motor or sensory disorders in both lower limbs as the first symptoms. On MRA, the dilated filum terminale vein or radicular vein was seen in 23/30 (76.7%) patients with lumbar spinal dural arteriovenous fistulas and 8/8 (100%) patients with sacral spinal dural arteriovenous fistulas. T2W intramedullary abnormally high signal intensity areas were found in all lumbosacral spinal dural arteriovenous fistula patients, with involvement of the conus present in 35/38 (92.1%) patients. The "missing piece sign" in the intramedullary enhancement area was seen in 29/38 (76.3%) patients. Dilatation of the filum terminale vein or radicular vein is powerful evidence for diagnosis of lumbosacral spinal dural arteriovenous fistulas, especially for sacral spinal dural arteriovenous fistulas. T2W intramedullary hyperintensity in the thoracic spinal cord and conus, and the missing-piece sign could be indicative of lumbosacral spinal dural arteriovenous fistula.

Inflammation and subsequent nociceptor sensitization in the bone marrow are involved in an animal model of osteoarthritis pain

AimsThis study aimed to determine whether pathological changes in the bone marrow cause Osteoarthritis (OA) pain based on magnetic resonance imaging (MRI), immunohistochemistry, and electrophysiology. Main methodsAdjuvant-induced arthritis (AIA) was achieved by injecting 150 μL of complete Freund's adjuvant into the right knee joints of male Sprague-Dawley rats. AIA rats were compared with saline-injected rats. Key findingsAIA significantly induced mechanical hyperalgesia and spontaneous pain in the right hind paw 1–14 days after induction. Intratibial injection of 50 μL of 1 % lidocaine significantly suppressed AIA-induced mechanical hyperalgesia (p = 0.0001) and spontaneous pain (p = 0.0006) 3 days after induction. In T2-weighted MRI, AIA induced high-signal intensity within the proximal tibial metaphysis, and the mean T2 values in this area significantly increased on days 3 (p = 0.0043) and 14 (p = 0.0012) after induction. AIA induced intraosseous edema and significantly increased the number of intraosseous granulocytes on days 3 (p < 0.0001) and 14 (p < 0.0001) after induction. The electrophysiological study on days 3–7 after induction showed significantly increased spontaneous firing rates (p = 0.0166) and evoked responses to cutaneous stimuli (brush, p < 0.0001; pinching, p = 0.0359) in the right hind paw plantar surface and intratibial stimuli (p = 0.0002) in wide-dynamic-range neurons of the spinal dorsal horn. SignificanceIntraosseous changes caused by OA induce hypersensitivity in the sensory afferents innervating bone marrow may be involved in OA pain. Novel bone marrow-targeted therapies could be beneficial for treating OA pain.

Comparison of gadolinium-based contrast agents for MR cholangiography in saline, blood and bile: a phantom study

BackgroundWe compared T1- and T2-weighted signal intensities of liver-specific (gadoxetate, gadobenate) and non-specific (gadoterate) gadolinium contrast agents (CAs) in a bile phantom.MethodsIn a phantom study, gadoxetate, gadobenate, and gadoterate were diluted in saline, blood, and bile at different concentrations (0, 0.25, 0.5. 1, 2.5, 5, 10, and 25 mM) and imaged in a 3-T magnetic resonance imaging (MRI) system using T1- and T2-weighted sequences. The maximum signal intensities of CAs were compared for each sequence separately and across all T1-weighted sequences using one-way ANOVA.ResultsUsing T1-weighted sequences, CA concentration-dependent signal intensity increase was followed by decrease due to T2* effects. Comparing CAs for each sequence in bile yielded higher maximum signal intensities with gadobenate than gadoxetate and gadoterate using T1-weighted spin-echo (p < 0.010), multiecho gradient- and spin-echo (p < 0.001), and T1-weighted high-resolution isotropic volume excitation (eTHRIVE) sequences (p < 0.010). Comparing across all T1-weighted sequences in the bile phantom, gadobenate imaged using T1-weighted turbo field-echo (TFE) sequence showed the highest signal intensity, significantly higher than that using other CAs agents or sequences (p < 0.004) except for gadobenate and gadoxetate evaluated with three-dimensional multiecho fast field-echo (3D-mFFE) and gadoxetate with T1-weighted TFE sequence (p > 0.141). Signal reduction with CA concentration-dependent decrease was observed on T2-weighted images.ConclusionIn this bile phantom study of gadolinium-based CA, gadobenate and gadoxetate showed high signal intensity with T1-weighted TFE and 3D-mFFE sequences, which supports their potential utility for contrast-enhanced hepatobiliary MRI.Key points• Contrast-enhanced magnetic resonance (MR) cholangiography depends on contrast agent type, kinetics, and concentration in bile,• We compared signal intensities of three contrast agents in a bile phantom study.• Gadobenate, gadoxetate, and gadoterate demonstrated different signal intensities at identical concentrations.• Gadoxetate and gadobenate showed high signal intensities on T1-weighted MR sequences.

Teaching Video NeuroImages: A Triad of Tremor, Ataxia, and Cognitive Impairment

A 67-year-old woman presented with a 2-year history of forgetfulness and unsteadiness. She scored 17 on the Montreal Cognitive Assessment. She had tremor of head and upper limbs (video 1) since early adulthood, which was diagnosed as essential tremor. Brain MRI showed leukoencephalopathy and high signal intensity along the corticomedullary junction on diffusion-weighted images (figure 1). The diagnosis of adult-onset neuronal intranuclear inclusion disease (NIID) was confirmed by skin biopsy showing eosinophilic intranuclear inclusions (figure 2).1 NIID is a clinically heterogeneous rare neurodegenerative disease.2 Its characteristic MRI pattern should prompt confirmation of the diagnosis by skin biopsy.

Measurement of Doppler effects in a cryogenic buffer-gas cell

Buffer-gas cooling is a universal cooling technique for molecules and used for various purposes. One of its applications is using molecules inside a buffer-gas cell for low-temperature spectroscopy. Although a high-intensity signal is expected in the cell, complex molecular dynamics is a drawback for precise spectroscopy. In this study, we performed high-resolution absorption spectroscopy of low-J transitions in the $\tilde{A}^2\Pi (0,0,0)-\tilde{X}^2\Sigma ^+(0,0,0)$ band of calcium monohydroxide (CaOH). CaOH molecules were produced by laser ablation in a copper cell and cooled to $\sim$5\,K using helium buffer gas. We probed the Doppler effects in a buffer-gas cell by injecting counter-propagating lasers inside the cell. The time evolutions of the Doppler width and shift were simulated using a dedicated Monte Carlo simulation and compared with data.

Clinical and imaging features of Kaposiform hemangioendothelioma in infants

ObjectiveKaposiform hemangioendothelioma (KHE) is a locally aggressive tumor of vascular origin. This study investigated the clinical and imaging features of KHE to provide a reference for its early diagnosis. MethodsThe clinical and imaging findings of 27 clinically confirmed KHE cases (including 21 with focal lesions and 6 with diffuse lesions) between January 2016 and December 2021 were retrospectively analyzed. ResultsThe mean age of the 27 patients was 105 ± 80.27 days. Twenty-two (81.5%) of these patients had Kasabach–Merritt phenomenon. Most KHEs were located in the trunk and/or extremities (22/27). Ultrasonography showed heterogeneous echogenicity and/or striated hypoechoic bands with abundant or patchy blood flow within the tumor. On plain computed tomography (CT), they appeared as heterogeneous lesions isodense with the muscles, with a CT value of 29.58 ± 11.53 HU. In the arterial phase, the KHEs showed striated or lamellar heterogeneous enhancement, with a CT value of 153.91 ± 52.11 HU after enhancement. All KHEs showed uneven and high signal intensity on T2-weighted imaging, mixed high and low signal intensity on fat-saturated images, and no significant diffusion restriction on diffusion-weighted imaging. ConclusionKHEs can occur in various locations and present as highly infiltrative and heterogeneous masses that can invade the skin, adjacent muscles, and bones. A vascularized mass with purpuric skin changes, with uneven and high T2WI signal is highly suggestive of the diagnosis of KHE.

Fluorescence Lifetime Macro Imager for Biomedical Applications

This paper presents a new photoluminescence lifetime imager designed to map the molecular oxygen (O2) concentration in different phosphorescent samples ranging from solid-state, O2-sensitive coatings to live animal tissue samples stained with soluble O2-sensitive probes. In particular, the nanoparticle-based near-infrared probe NanO2-IR, which is excitable with a 625 nm light-emitting diode (LED) and emits at 760 nm, was used. The imaging system is based on the Timepix3 camera (Tpx3Cam) and the opto-mechanical adaptor, which also houses an image intensifier. O2 phosphorescence lifetime imaging microscopy (PLIM) is commonly required for various studies, but current platforms have limitations in their accuracy, general flexibility, and usability. The system presented here is a fast and highly sensitive imager, which is built on an integrated optical sensor and readout chip module, Tpx3Cam. It is shown to produce high-intensity phosphorescence signals and stable lifetime values from surface-stained intestinal tissue samples or intraluminally stained fragments of the large intestine and allows the detailed mapping of tissue O2 levels in about 20 s or less. Initial experiments on the imaging of hypoxia in grafted tumors in unconscious animals are also presented. We also describe how the imager can be re-configured for use with O2-sensitive materials based on Pt-porphyrin dyes using a 390 nm LED for the excitation and a bandpass 650 nm filter for emission. Overall, the PLIM imager was found to produce accurate quantitative measurements of lifetime values for the probes used and respective two-dimensional maps of the O2 concentration. It is also useful for the metabolic imaging of ex vivo tissue models and live animals.

Ultra-sensitive specific detection of nucleic acids in pathogenic infections by Ta2C-MXene sensitization-based ultrafine plasmon spectroscopy combs

Accurate and rapid population-scale screening techniques based on SARS-CoV-2 RNA are essential in preventing and controlling the COVID-19 epidemic. However, the sensitivity and specificity of the assay signal are challenged by the problems of target dilution and sample contamination inherent in high-volume pooled testing. Here, we reported a collaborative system of high-loaded hybrid probes targeting N and OFR1a coupling with the novel Ta2C-M/Au/TFBG biosensor, providing high-intensity vector signals for detecting SARS-CoV-2. The method relies on a segmental modification approach to saturable modify multiple activation sites of SARS-CoV-2 on the high-performance Ta2C-M surface. The coupling of multi-site synergy with composite excited TFBG results in excellent signal transduction, detection limits (0.2 pg/mL), and hybridization efficiency. Without relying on amplification, the collaborative system achieved specific differentiation of 30 clinical samples in an average diagnostic time of 1.8 min. In addition, for the first time, a kinetic determination of dilution mixed samples was achieved and showed a high-intensity carrier signal and fantastic stability. Therefore, it can be used as a collaborative, integrated tool to play a massive role in the screening, prevention, and control of COVID-19 and other epidemics.

Spontaneous Bone Marrow Edema: Perfusion Abnormalities and Treatment with Surgical Decompression

Bone marrow edema (BME), also termed bone marrow lesions, is a syndrome characterized by bone pain and the appearance of high signal intensity on T2 fat-suppressed and short tau inversion recovery (STIR) MRI sequences. BME can be related to trauma or a variety of non-traumatic diseases, and current treatment modalities include non-steroidal anti-inflammatory drugs (NSAIDS), bisphosphonates, denosumab, extracorporeal shockwave therapy (ESWT), the vasoactive prostacyclin analogue iloprost, and surgical decompression. Spontaneous BME is a subset that has been observed with no apparent causative conditions. It is most likely caused by venous outflow obstruction and intraosseous hypertension. These are mechanistically related to impaired perfusion and ischemia in several models of BME and are related to bone remodeling. The association of perfusion abnormalities and bone pain provides the pathophysiological rationale for surgical decompression. We present a case of spontaneous BME and a second case of spontaneous migratory BME treated with surgical decompression and demonstrate resolution of pain and the high signal intensity on MRI. This report provides an integration of the clinical syndrome, MR imaging characteristics, circulatory pathophysiology, and treatment. It draws upon several studies to suggest that both the bone pain and the MRI characteristics are related to venous stasis, and when circulatory pathologies are relieved by decompression or fenestration, both the bone pain and the MRI signal abnormalities resolve.

Gadolinium enhancement in cervical dorsal roots in a patient with acute autonomic and sensory neuropathy: a case report

BackgroundWe report an enhancement of the dorsal roots on gadolinium-enhanced cervical magnetic resonance imaging (MRI) in a patient with acute autonomic and sensory neuropathy (AASN).Case presentationA 38-year-old woman visited our university hospital for dizziness and fainting while rising from sitting or lying down and a tingling sensation in the whole body, including her limbs, torso, and abdomen, which was sustained for 15 days. The patient had hyperalgesia in nearly her entire body and slight motor weakness in her bilateral upper and lower limbs. Autonomic dysfunction was confirmed using autonomic testing. Furthermore, the nerve conduction study showed an absence of sensory nerve action potentials in all evaluated peripheral nerves. Cervical MRI was performed 18 days after dysautonomia onset. In the axial T1-gadolinum-enhanced MRIs, enhancement in cervical ventral and dorsal nerve roots and the posterior column of the spinal cord were observed, and the axial T2-weighted MRI showed high signal intensity in the posterior column of the cervical spinal cord. Considering the clinical, electrophysiological and imaging findings, the patient was diagnosed with AASN. A total dose of 90 g (2 g/kg) of intravenous immunoglobulin was administered over 5 days. At the follow-up at 4 years after AASN symptom onset, the hyperalgesia and orthostatic hypotension symptoms improved. However, her systolic blood pressure intermittently decreased to < 80 mmHg.ConclusionGadolinium-enhanced MRI may facilitate the accurate and prompt diagnosis of AASN.

A Scoping Review of Cerebral Doppler Arterial Waveforms in Infants.

Cerebral Doppler ultrasound has been an important tool in pediatric diagnostics and prognostics for decades. Although the Doppler spectrum can provide detailed information on cerebral perfusion, the measured spectrum is often reduced to simple numerical parameters. To help pediatric clinicians recognize the visual characteristics of disease-associated Doppler spectra and identify possible areas for future research, a scoping review of primary studies on cerebral Doppler arterial waveforms in infants was performed. A systematic search in three online bibliographic databases yielded 4898 unique records. Among these, 179 studies included cerebral Doppler spectra for at least five infants below 1 y of age. The studies describe variations in the cerebral waveforms related to physiological changes (43%), pathology (62%) and medical interventions (40%). Characteristics were typically reported as resistance index (64%), peak systolic velocity (43%) or end-diastolic velocity (39%). Most studies focused on the anterior (59%) and middle (42%) cerebral arteries. Our review highlights the need for a more standardized terminology to describe cerebral velocity waveforms and for precise definitions of Doppler parameters. We provide a list of reporting variables that may facilitate unambiguous reports. Future studies may gain from combining multiple Doppler parameters to use more of the information encoded in the Doppler spectrum, investigating the full spectrum itself and using the possibilities for long-term monitoring with Doppler ultrasound.

WHU‐GRACE‐GPD01s: A Series of Constrained Monthly Gravity Field Solutions Derived From GRACE‐Based Geopotential Differences

AbstractTo suppress the correlated noise of Gravity Recovery and Climate Experiment (GRACE) spherical harmonic (SH) solutions, we developed a series of constrained monthly gravity field solutions named WHU‐GRACE‐GPD01s from August 2002 to July 2016 using GRACE‐based geopotential differences. The constrained solutions were estimated using Kaula regularization, and the optimal regularization parameters were adaptively determined from the GRACE data itself through variance component estimation. The performance of the constrained WHU‐GRACE‐GPD01s solutions was validated against the official SH solutions (GFZ, JPL, and CSR RL06) and mass concentration (mascon) solutions (CSR RL06M) at global and regional scales. The results demonstrate that mass changes derived from the constrained solutions and official SH solutions with DDK4 filtering are in good agreement, but the constrained solutions present weaker longitudinal stripes and have a lower noise level at regional scales (e.g., in the Middle Pacific Ocean and Sahara Desert). Furthermore, regional mass changes (e.g., major river basins, Greenland, and Antarctic ice sheet) inferred from the constrained solutions agree with the ones derived from the official SH solutions with DDK4 filtering. The constrained solutions also have a higher signal intensity and smaller spatial leakages as compared to the CSR RL06 SH solutions with spatial filtering (Gaussian filtering plus de‐striping). For the problematic months, the constrained solutions are more reliable than the official SH solutions using spatial filtering or DDK4 filtering, and are closer to CSR RL06M mascon solutions. These validations demonstrate that our constrained solutions are comparable to the official SH solutions and can be used without postprocessing.