Magnetic Resonance Imaging Changes Research Articles

MP73-13 MRI ANALYSIS OF PROSTATE MORPHOMETRY AND PERIPROSTATIC ANATOMICAL RELATIONSHIPS BEFORE AND AFTER PARTIAL HIGH-INTENSITY FOCUSED ULTRASOUND TREATMENT OF LOCALIZED PROSTATE CANCER.

You have accessJournal of UrologyCME1 Apr 2023MP73-13 MRI ANALYSIS OF PROSTATE MORPHOMETRY AND PERIPROSTATIC ANATOMICAL RELATIONSHIPS BEFORE AND AFTER PARTIAL HIGH-INTENSITY FOCUSED ULTRASOUND TREATMENT OF LOCALIZED PROSTATE CANCER. Denis Seguier, Srinath Kotarmarti, Zoe Michael, Rajan Gupta, Cary Robertson, Thomas Polascik, Jonathan Olivier, and Arnauld Villers Denis SeguierDenis Seguier More articles by this author , Srinath KotarmartiSrinath Kotarmarti More articles by this author , Zoe MichaelZoe Michael More articles by this author , Rajan GuptaRajan Gupta More articles by this author , Cary RobertsonCary Robertson More articles by this author , Thomas PolascikThomas Polascik More articles by this author , Jonathan OlivierJonathan Olivier More articles by this author , and Arnauld VillersArnauld Villers More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003341.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Little is known regarding anatomical changes to peri-prostatic tissues after focal high intensity focused ultrasound (fHIFU) for localized prostate cancer. We sought to provide a novel approach to assess prostato-pelvic anatomical morphometric magnetic resonance imaging (MRI) changes post- fHIFU. METHODS: 38 patients (Pts) over two institutions (Lille University Hospital and Duke University Hospital) undergoing fHIFU with pre-and post-treatment (Pre-/Post-Tx) (≥6 months) MRI were included. Pre- and post-TX. MRIs were assessed for prostate and treated region volume. Distances to pubic bone and rectum were measured to account for the post-Tx periprostatic changes. Two subgroups were also identified, those with recurrence (positive biopsy and/or subsequent whole gland Tx) and those recurrence-free. Specific MRI features were also described within those two groups. RESULTS: The median treated-lobe volume was of 16.8 ml (IQR 10.6-21.5) on pre-Tx MRI and of 10.2 ml on post-Tx MRI (IQR 7.2-14.8). Comparison on pre-Tx MRI vs. post-Tx MRI showed a significant difference (p<0.01). The median percentage reduction of treated lobe volume for the entire cohort was 28.5% (IQR: 17-47). No significant difference was identified between the non-recurring group and the recurring group for prostate volume and treated lobe-volume both at pre- and post-Tx. Analysis of prostato-rectal measurements was conducted in 17 Pts. The mean value of the median prostato-rectal distance was 2 mm (SD 1) in pre-Tx and 1.97 mm (SD 1.1) in post-Tx. We noted no significant difference in either the pre-Tx or post-Tx configuration (p=0.78 and p=0.1 respectively) between the groups of recurring vs. non-recurring Pts. 13 Pts were qualitatively classified as presenting an aspect of loss of symmetry in the prostato-rectal space on post-Tx MRI. No significative difference existed between the recurring and non-recurring group for this parameter. CONCLUSIONS: With this study, we described a novel standardized method of morphometric alteration post-fHIFU. This preliminary work incite further studies to assess the clinical significance and implications of these results in a larger prospective cohort. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1040 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Denis Seguier More articles by this author Srinath Kotarmarti More articles by this author Zoe Michael More articles by this author Rajan Gupta More articles by this author Cary Robertson More articles by this author Thomas Polascik More articles by this author Jonathan Olivier More articles by this author Arnauld Villers More articles by this author Expand All Advertisement PDF downloadLoading ...

Spatial Correspondence of LSD-Induced Variations on Brain Functioning at Rest With Serotonin Receptor Expression

BackgroundLysergic acid diethylamide (LSD) is an atypical psychedelic compound that exerts its effects through pleiotropic actions, mainly involving 1A/2A serotoninergic (5-HT) receptor subtypes. However, the mechanisms by which LSD promotes a reorganization of the brain’s functional activity and connectivity are still partially unknown. MethodsOur study analyzed resting-state functional magnetic resonance imaging data acquired from 15 healthy volunteers undergoing LSD single-dose intake. A voxelwise analysis investigated the alterations of the brain’s intrinsic functional connectivity and local signal amplitude induced by LSD or by a placebo. Quantitative comparisons assessed the spatial overlap between these 2 indices of functional reorganization and the topography of receptor expression obtained from a publicly available collection of in vivo, whole-brain atlases. Finally, linear regression models explored the relationships between changes in resting-state functional magnetic resonance imaging and behavioral aspects of the psychedelic experience. ResultsLSD elicited modifications of the cortical functional architecture that spatially overlapped with the distribution of serotoninergic receptors. Local signal amplitude and functional connectivity increased in regions belonging to the default mode and attention networks associated with high expression of 5-HT2A receptors. These functional changes correlate with the occurrence of simple and complex visual hallucinations. At the same time, a decrease in local signal amplitude and intrinsic connectivity was observed in limbic areas, which are dense with 5-HT1A receptors. ConclusionsThis study provides new insights into the neural processes underlying the brain network reconfiguration induced by LSD. It also identifies a topographical relationship between opposite effects on brain functioning and the spatial distribution of different 5-HT receptors.

Diagnosis of Parkinson’s disease based on 3D ResNet: The frontal lobe is crucial

Parkinson’s disease (PD) is a serious neurological disease. Many studies have preseted regions of interest such as substantia nigra (SN) for PD detection from magnetic resonance imaging (MRI). However, the SN is not the only region with remarkable tissue changes in PD MRIs. Patients with Prodromal Parkinson’s Disease usually present with non-motor symptoms, and the associated brain regions may show varying degrees of damage on imaging. Therefore, exploring PD-related regions from whole-brain MRI is essential. In this study, we proposed an interpretable PD detection framework, including PD classification and feature region visualization. Specifically, we constructed a 3D ResNet model that could detect PD from whole-brain MRIs and discover other brain regions related to PD through 3D Gradient-weighted Class Activation Mapping (Grad-CAM) and Unified Parkinson’s Disease Rating Scale (UPDRS). We obtained T1-Weighted MRIs from the Parkinson’s Progression Markers Initiative (PPMI) database. The average classification accuracy of the 5-fold cross-validation and held-out dataset reached 96.1% and 94.5%, respectively. In addition, we used the 3D Grad-CAM framework to extract the weight of the feature map and obtain visual interpretation. The heat map highlighted the regions that were crucial for PD classification and found significant differences between PD and HC in frontal lobe related to linguistic semantic disorders. The UPDRS scores of PD and HC on the linguistic semantic function items were also remarkably different. Combined with previous studies, this work verified the significance of the frontal lobe and proved that the correlation between the frontal lobe and the pathogenesis of PD was explanatory.

MRI of neurosyphilis with mesiotemporal lobe lesions of "knife-cut sign” on MRI: A case report and literature review

Neurosyphilis with mesiotemporal lobe lesions remains a difficult entity to diagnose, especially when it mimics herpes simplex encephalitis (HSE). Here, we report what appeared to be the first case of mesiotemporal imaging of neurosyphilis presenting as a “knife-cut” sign and mimicking HSE pathological hallmarks on imaging. The magnetic resonance imaging (MRI) changes in neurosyphilis and HSE were indistinguishable in the initial diagnosis because of the common involvement of the mesiotemporal lobe. Neurosyphilis was diagnostically confirmed by positive readings in the treponema pallidum hemagglutination assay (TPHA), rapid plasma reagin (RPR) and cerebrospinal fluid-polymerase chain reaction (CSF-PCR) tests for Treponema pallidum infection. Neurosyphilis and HSE had similar clinical features and signs on MRI, except the knife-cut sign which is a common diagnosis in HSE. Therefore, neurosyphilis with mesiotemporal changes and knife-cut signs on MRI should be evaluated in the differential diagnosis in all patients, as similar changes may also occur in HSE patients. The literature review of published articles between 1997 and 2020 was conducted to further validate our clinical observations and discuss diagnostic and treatment options for neurosyphilis with mesiotemporal lobe lesions.

MRI of wrist and diffusion tensor imaging of the median nerve in patients with carpal tunnel syndrome.

Diagnosis of carpal tunnel syndrome (CTS) is based on the clinical symptoms and nerve conduction study. Magnetic resonance imaging (MRI) is non-invasive objective tool for assessing the median nerve and carpal tunnel. The purpose of this study was to evaluate MRI changes in patients with CTS, and compare them with healthy subjects. Forty-three CTS patients and 43 age matched control were included and scanned in a 3T MRI scanner. Cross-sectional areas (CSA) of median nerve were measured at the level of distal radio-ulnar joint level (CSA1), proximal row of carpal bone (CSA2), and hook of hamate (CSA3). Flattening ratio (FR) of median nerve, thickness of flexor retinaculum, median nerve signal intensity, and thenar muscles were assessed. Fractional anisotropy (FA), average diffusion coefficient (ADC), and radial diffusivity (RD) of median nerve of CTS patients were obtained from diffusion tensor imaging (DTI) and compared with those of controls. Thirty-three patients (76.7%) were female. Mean duration of the pain was 7.4 ± 2.6 months. The mean CSA1 (13.2 ± 4.2 mm2), CSA2 (12.5 ± 3.5 mm2), and CSA3 (9.2 ± 1.5 mm2) in CTS patients were significantly higher compared to control group: CSA1 (10.15 ± 1.64 mm2), CSA2 (9.38 ± 1.37 mm2), and CSA3 (8.4 ± 0.9 mm2), (P = 0.001 in all). The mean FR of median nerve and thickness of flexor retinaculum were increased in CTS patients. The mean FA was reduced in CTS patients compared to control proximal to carpal tunnel and within the tunnel. Mean ADC and RD values were higher in CTS patients as compared to control for both levels. MRI can detect subtle changes in the median nerve and thenar muscles in CTS and may be useful in equivocal cases and to exclude secondary causes of CTS. DTI shows reduced FA and increased ADC and RD in CTS patients.

Frequency and Prognostic Relevance of Volumetric MRI Changes in Contrast- and Non-Contrast-Enhancing Tumor Compartments between Surgery and Radiotherapy of IDHwt Glioblastoma

In newly diagnosed IDH-wildtype glioblastoma, the frequency and prognostic relevance of tumor regrowth between resection and the initiation of adjuvant radiochemotherapy are unclear. In this retrospective single-center study we included 64 consecutive cases, for whom magnetic resonance imaging (MRI) was available for both the volumetric assessment of the extent of resection immediately after surgery as well as the volumetric target delineation before the initiation of adjuvant radiochemotherapy (time interval: 15.5 ± 1.9 days). Overall, a median new contrast-enhancement volume was seen in 21/64 individuals (33%, 1.5 ± 1.5 cm3), and new non-contrast lesion volume in 18/64 patients (28%, 5.0 ± 2.3 cm3). A multidisciplinary in-depth review revealed that new contrast-enhancement was either due to (I) the progression of contrast-enhancing tumor remnants in 6/21 patients or (II) distant contrast-enhancing foci or breakdown of the blood-brain barrier in previously non-contrast-enhancing tumor remnants in 5/21 patients, whereas it was unspecific or due to ischemia in 10/21 patients. For non-contrast-enhancing lesions, three of eighteen had progression of non-contrast-enhancing tumor remnants and fifteen of eighteen had unspecific changes or changes due to ischemia. There was no significant association between findings consistent with tumor regrowth and a less favorable outcome (overall survival: 14 vs. 19 months; p = 0.423). These findings support the rationale that analysis of the postsurgical remaining tumor-volume for prognostic stratification should be carried out on immediate postoperative MRI (<72 h), as unspecific changes are common. However, tumor regrowth including distant foci may occur in a subset of IDH-wildtype glioblastoma patients diagnosed per WHO 2021 classification. Thus, MRI imaging prior to radiotherapy should be obtained to adjust radiotherapy planning accordingly.

Low occurrence of MRI spinal changes in elite climbing athletes; a cross-sectional study

ObjectivesTo examine the occurrence of magnetic resonance imaging (MRI) changes in the thoracolumbar spine among elite climbing athletes.MethodsAll climbers of the Swedish national sport climbing team (n = 8), and individuals having trained for selection to the national team (n = 11), were prospectively included. A control group, matched in age and sex, were recruited. All participants underwent a thoracolumbar MRI (1.5 T, T1- and T2-weighted imaging), evaluated according to Pfirrmann classification, modified Endplate defect score, Modic changes, apophyseal injuries and spondylolisthesis. Pfirrmann ≥ 3, Endplate defect score ≥ 2 and Modic ≥ 1 was defined as degenerative findings.ResultsFifteen individuals, 8 women, participated in both the climbing group (mean age 23.1, SD 3.2 years) and the control group respectively (mean age 24.3, SD 1.5 years). In the climbing group, 6.1% of the thoracic and 10.6% of the lumbar intervertebral discs showed signs of degeneration according to Pfirrmann. One disc with a grade above 3 was present. Modic changes in the thoracic/lumbar spine were prevalent in 1.7%/1.3% of the vertebrae. Degenerative endplate changes according to the Endplate defect score were found in 8.9% and 6.6% of the thoracic and lumbar spinal segments of the climbing group, respectively. Two apophyseal injuries were found, while no participants displayed signs of spondylolisthesis. There was no difference in point-prevalence of radiographic spinal changes between climbers and controls (0.07 < p < 1.0).ConclusionIn this small cross-sectional study, only a low proportion of elite climbers displayed changes of the spinal endplates or intervertebral discs, as opposed to other sports with high spinal loads. Most observed abnormalities were low grade degenerative changes and did not differ statistically compared to controls.

High serum neurofilament light chain levels correlate with brain atrophy and physical disability in multiple sclerosis.

Serum neurofilament light chain (sNfL) is a promising biomarker of neuroaxonal damage in persons with multiple sclerosis (pwMS). In cross-sectional studies, sNfL has been associated with disease activity and brain magnetic resonance imaging (MRI) changes; however, it is still unclear to what extent in particular high sNfL levels impact on subsequent disease evolution. sNfL was quantified by an ultrasensitive single molecule array (Simoa) in 199 pwMS (median age=34.2 years, 64.3% female) and 49 controls. All pwMS underwent 3-T MRI to assess global and compartmental normalized brain volumes, T2-lesion load, and cortical mean thickness. Follow-up data and serum samples were available in 144 pwMS (median follow-up time=3.8 years). Linear and binary logistic models were used to estimate the independent contribution of sNfL for changes in MRI and Expanded Disability Status Scale (EDSS). Age-corrected sNfL z-scores from a normative database of healthy controls were used for sensitivity analyses. High sNfL levels at baseline were associated with atrophy measures of the whole brain (standardized beta coefficient βj= -0.352, p< 0.001), white matter (βj= -0.229, p= 0.007), thalamus (βj= -0.372, p= 0.004), and putamen (βj= -1.687, p= 0.012). pwMS with high levels of sNfL at baseline and follow-up had a greater risk of EDSS worsening (p= 0.007). Already single time point elevation of sNfL has a distinct effect on brain volume changes over a short-term period, and repeated high levels of sNfL indicate accumulating physical disability. Serial assessment of sNfL may provide added value in the clinical management of pwMS.

Multidisciplinary Conservative Treatment Outcomes of in-Patient Physiotherapy Set-Up Among Patients with Lumbar Disc Herniation in Dhaka City, Bangladesh: A Retrospective, Cross-Sectional Study.

The study aimed to determine the outcome of Multidisciplinary physiotherapist-led conservative treatment of lumbar disc herniation at an in-patient set-up of a specialized spine center in Dhaka, Bangladesh. This was a retrospective cross-sectional study of 228 cases completing treatment and follow-up sessions. The outcome was evaluated as pain at rest and five different functional positions, neurological recovery, and Magnetic resonance imaging (MRI) changes during discharge and follow-up. 80.3% had a complete recovery with a typical motor and sensory status, no limitations in straight leg raise (SLR), no cauda equina symptom (CES), and no or <3 pain during more than 30 minutes of daily living activities. Statistically significant changes were noted at all outcome measures at the follow-up (day 90), compared to baseline (day 1) P<0.01. In the posthoc tests, pain, SLR, and CES had the most significant improvement at discharge (day 12) compared to the baseline (P < 0.01) and at follow-up compared to discharge (P < 0.01). No major adverse events noted. Physiotherapist-led in-patient treatment results in significant resting and functional pain outcomes in 12 days. Also, the improvements in neurological recovery and normalizing disc position are statistically significant in 90 days.

Magnetic resonance imaging presentation of diffuse and focal adenomyosis before and after pregnancy

Research questionIs there a change in magnetic resonance imaging (MRI) criteria of diffuse and focal phenotypes of adenomyosis before and after pregnancy? DesignA retrospective, monocentric, observational study in a single academic tertiary referral centre for endometriosis diagnosis and management. Women were followed for symptomatic adenomyosis, and without a prior history of surgery who give birth after 24+0 weeks. For each patient, pelvic MRI pre- and post-pregnancy was performed by two experienced radiologists with the same image acquisition protocol. Diffuse and focal adenomyosis MRI presentation were analysed before and after pregnancy. ResultsBetween January 2010 and September 2020, of the 139 patients analysed, 96 (69.1%) had adenomyosis at MRI distributed as follow: 22 (15.8%) presented diffuse adenomyosis, 55 (39.6%) focal adenomyosis and 19 (13.7%) both phenotypes. The frequency of isolated diffuse adenomyosis on MRI was significantly lower before versus after pregnancy (n = 22 [15.8%] versus n = 41 [29.5%], P = 0.01). The frequency of isolated focal adenomyosis was significantly higher before pregnancy than after pregnancy (n = 55 [39.6%] versus n = 34 [24.5%], P = 0.01). The mean volume of all focal adenomyosis lesions on MRI decreased significantly after pregnancy, from 6.7 ± 2.5 mm3 to 6.4 ± 2.3 mm3, P = 0.01. ConclusionThe current data indicate that, based on MRI, there is an increase in diffuse adenomyosis and a decrease in focal adenomyosis after pregnancy.

Laser interstitial thermal therapy in the treatment of brain metastases: the relationship between changes in postoperative magnetic resonance imaging characteristics and tumor recurrence.

Laser interstitial thermal therapy (LITT) has been used to treat brain metastases (BMs) in several countries, and its safety and effectiveness have been confirmed. In most cases, magnetic resonance imaging (MRI) reveals an increase in tumor volume with an enhanced margin after LITT. However, little is known about the relationship between this MRI change and tumor recurrence. We report the first case series of BMs treated by LITT in China to evaluate the clinical characteristics and predictive factors of tumor recurrence. Patients with less than four brain metastatic lesions and a Karnofsky performance status (KPS) > 70 were eligible for study inclusion. Standard LITT procedures were performed, and a follow-up MRI was performed to analyze the radiographic changes, especially the volume ratio of the enhanced margin and the whole lesion on MRI at 30days postoperatively. All the volume-related data were delineated and calculated using 3D Slicer software. Related predictors were also collected to evaluate the correlation with local tumor control. Eighteen patients with nineteen lesions were enrolled for treatment and follow-up. Primary tumor histology included pulmonary carcinoma (n = 11) and breast cancer (n = 4). On average, the tumor size measured 3.01 cm3 (range, 0.40-7.40 cm3), the total ablation time was 13.58min (range, 2.88-37.15min), and the complete ablation rate was 92.4% (range, 29.2-100%). Comparing 3s0-day follow-up MRI results with preoperative MRI findings, 18 lesions showed a 2.28-fold (range, 1.21-4.88) volume increase; all the lesions displayed an enhanced component with a volume ratio of 42.35% (range, 10.14-100%). Five patients experienced tumor recurrence, and the local tumor control rates at 90days and 180days of follow-up were 68.4% and 66.7%, respectively. Univariate analysis indicated that the primary tumor, ablation rate, and enhanced volume ratio (EVR) > 40% in the 30-day MRI were associated with tumor recurrence, whereas multivariate analysis showed that only EVR > 40% was a predictive factor of local control. LITT is a minimally invasive method used to ablate brain metastases which can be used as the first-line treatment for BM patients under certain indications. After LITT, most tumors showed volume enlargement on the 30-day MRI scan, and EVR > 40% on the 30-day MRI may indicate late tumor recurrence.

Image Quality and Artifact Reduction of a Cochlear Implant With Rotatable Magnets.

To determine if metal reduction magnetic resonance imaging sequences and changes in implant placement minimize artifact from cochlear implants and improve visualization of intracranial structures. Cadaveric study. Tertiary referral center. Five cadaveric heads. Specimens were implanted with Advanced Bionics HiRes Ultra3D devices at nasion-external auditory canal angles of 90, 120, and 160 degrees, and distances from the external auditory canal of 9 or 12 cm. Standard brain/internal auditory canal (IAC) sequences with metal artifact reducing technique were acquired in a 1.5T scanner. The primary outcome was visibility of 14 intracranial structures graded on a 4-point scale (1, structures <50% visible; 2, >50% visible with some areas nonvisible from artifact; 3, artifact present but adequate for diagnosis; and 4, high quality). Scores were determined by experienced head and neck radiologists and compared with one-way analysis of variance. Imaging sequences included axial 5-mm whole-brain turbo spin echo (TSE) T2 with right to left and anterior to posterior encoding, fluid-attenuation inversion recovery high bandwidth, axial 5-mm whole-brain slice-encoding metal artifact correction (SEMAC), axial IAC constructive interference in steady state, and axial 3-mm T1 IAC with and without fat saturation. T1 IACs in axial and coronal planes were best for ipsilateral structures overall (mean [standard deviation {SD}], 3.8 [0.6] and 3.8 [0.5]). SEMAC (mean [SD], 3.5 [0.8]) was superior to TSE with anterior to posterior encoding (mean [SD], 3.5 [0.9) for ipsilateral cortex, cerebellopontine angle, and brainstem/cerebellum, and equivalent for the inner ear. Constructive interference in steady state and T1 with fat saturation were poor for all ipsilateral structures (mean, 2.8 [ p < 0.01]; mean, 3.1 [ p < 0.01]). The 120 degrees/12 cm position was overall best, although the 120 degrees/9 cm position still afforded visualization of ipsilateral structures; other angles and distances conferred slight advantages for specific structures of interest. SEMAC and T2 TSE with anterior to posterior encoding sequences provide artifact suppression while retaining excellent image quality. Different placement angles did not confer improvement in visualization, although placement distances provided slight advantages for some structures.

Magnetic resonance imaging of human variegated squirrel bornavirus 1 (VSBV-1) encephalitis reveals diagnostic pattern indistinguishable from Borna disease virus 1 (BoDV-1) encephalitis but typical for bornaviruses

ABSTRACT Human bornavirus encephalitis is an emerging disease caused by the variegated squirrel bornavirus 1 (VSBV-1) and the Borna disease virus 1 (BoDV-1). While characteristic brain magnetic resonance imaging (MRI) changes have been described for BoDV-1 encephalitis, only scarce diagnostic data in VSBV-1 encephalitis exist. We systematically analysed brain MRI scans from all known VSBV-1 encephalitis patients. Initial and follow-up scans demonstrated characteristic T2 hyperintense lesions in the limbic system and the basal ganglia, followed by the brainstem. No involvement of the cerebellar cortex was seen. Deep white matter affection occurred in a later stage of the disease. Strict symmetry of pathologic changes was seen in 62%. T2 hyperintense areas were often associated with low T1 signal intensity and with mass effect. Sinusitis in three patients on the first MRI and an early involvement of the limbic system suggest an olfactory route of VSBV-1 entry. The viral spread could occur per continuitatem to adjacent anatomical brain regions or along specific neural tracts to more distant brain regions. The number and extent of lesions did not correlate with the length of patients’ survivals. The overall pattern closely resembles that described for BoDV-1 encephalitis. The exact bornavirus species can thus not be deduced from imaging results alone, and molecular testing and serology should be performed to confirm the causative bornavirus. As VSBV-1 is likely of tropical origin, and MRI investigations are increasingly available globally, imaging techniques might be helpful to facilitate an early presumptive diagnosis of VSBV-1 encephalitis when molecular and/or serological testing is not available.

Genetic models of cleavage-reduced and soluble TREM2 reveal distinct effects on myelination and microglia function in the cuprizone model

Triggering receptor expressed on myeloid cells 2 (TREM2) is a cell-surface immunoreceptor expressed on microglia, osteoclasts, dendritic cells and macrophages. Heterozygous loss-of-function mutations in TREM2, including mutations enhancing shedding form the cell surface, have been associated with myelin/neuronal loss and neuroinflammation in neurodegenerative diseases, such as Alzheimer`s disease and Frontotemporal Dementia. Using the cuprizone model, we investigated the involvement of soluble and cleavage-reduced TREM2 on central myelination processes in cleavage-reduced (TREM2-IPD), soluble-only (TREM2-sol), knockout (TREM2-KO) and wild-type (WT) mice. The TREM2-sol mouse is a new model with selective elimination of plasma membrane TREM2 and a reduced expression of soluble TREM2. In the acute cuprizone model demyelination and remyelination events were reflected by a T2-weighted signal intensity change in magnetic resonance imaging (MRI), most prominently in the external capsule (EC). In contrast to WT and TREM2-IPD, TREM2-sol and TREM2-KO showed an additional increase in MRI signal during the recovery phase. Histological analyses of TREM2-IPD animals revealed no recovery of neuroinflammation as well as of the lysosomal marker LAMP-1 and displayed enhanced cytokine/chemokine levels in the brain. TREM2-sol and, to a much lesser extent, TREM2-KO, however, despite presenting reduced levels of some cytokines/chemokines, showed persistent microgliosis and astrocytosis during recovery, with both homeostatic (TMEM119) as well as activated (LAMP-1) microglia markers increased. This was accompanied, specifically in the EC, by no myelin recovery, with appearance of myelin debris and axonal pathology, while oligodendrocytes recovered. In the chronic model consisting of 12-week cuprizone administration followed by 3-week recovery TREM2-IPD displayed sustained microgliosis and enhanced remyelination in the recovery phase. Taken together, our data suggest that sustained microglia activation led to increased remyelination, whereas microglia without plasma membrane TREM2 and only soluble TREM2 had reduced phagocytic activity despite efficient lysosomal function, as observed in bone marrow-derived macrophages, leading to a dysfunctional phenotype with improper myelin debris removal, lack of remyelination and axonal pathology following cuprizone intoxication.

Magnetic resonance imaging evidence for subclinical joint bleeding in a Dutch population of people with severe hemophilia on prophylaxis

BackgroundPrevious studies suggest that subclinical bleeding occurs in persons with hemophilia. ObjectivesThe aim of this study was to investigate whether patients with lifelong access to prophylaxis showed signs of previous subclinical bleeding on magnetic resonance imaging (MRI) in joints without a history of joint bleeding. MethodsThis single-center cross-sectional study included persons with severe hemophilia A on prophylaxis, aged 16 to 33 years, with lifetime bleeding records available. Per participant, 1 index joint without a history of joint bleeding was evaluated with 3-Tesla MRI, including hemosiderin sensitive sequences. MRI scans were reviewed according to the International Prophylaxis Study Group (IPSG) additive MRI scale (range, 0-17/joint). Hemosiderin deposits with/without synovial hypertrophy were considered signs of previous subclinical bleeding. Additionally, physical examination was performed, followed by ultrasound examination according to the Hemophilia Early Arthropathy Detection with Ultrasound protocol. ResultsIn 43 patients with a median age of 23.5 years, 43 joints (16 elbows, 13 knees, 14 ankles) without reported bleeds were evaluated with MRI. The median IPSG MRI score was 1 (range, 0-9). Signs of previous subclinical bleeding were observed in 7 of 43 joints (16%; 95% CI, 7-30): 7 of 7 joints showed hemosiderin deposits, with concomitant synovial hypertrophy in 2 of 7 joints. MRI changes were accompanied by swelling and ultrasound-detected synovial hypertrophy in 1 ankle only. None of the other joints showed abnormalities at physical examination and ultrasound. ConclusionIn this study, 16% of the joints without reported bleeds showed signs of previous subclinical bleeding, providing evidence for subclinical bleeding in people with severe hemophilia with lifelong access to prophylaxis.

Spectrum of Clinical Presentations, Imaging Findings, and HLA Types in Immune Checkpoint Inhibitor-Induced Hypophysitis.

Hypophysitis is a known immune-related adverse event (irAE) of immune checkpoint inhibitors (CPIs), commonly associated with CTLA-4 inhibitors and less often with PD-1/PD-L1 inhibitors. We aimed to determine clinical, imaging, and HLA characteristics of CPI-induced hypophysitis (CPI-hypophysitis). We examined the clinical and biochemical characteristics, magnetic resonance imaging (MRI) of the pituitary, and association with HLA type in patients with CPI-hypophysitis. Forty-nine patients were identified. Mean age was 61.3 years, 61.2% were men, 81.6% were Caucasian, 38.8% had melanoma, and 44.5% received PD-1/PD-L1 inhibitor monotherapy while the remainder received CTLA-4 inhibitor monotherapy or CTLA-4/PD-1 inhibitor combination therapy. A comparison of CTLA-4 inhibitor exposure vs PD-1/PD-L1 inhibitor monotherapy revealed faster time to CPI-hypophysitis (median 84 vs 185 days, P < .01) and abnormal pituitary appearance on MRI (odds ratio 7.00, P = .03). We observed effect modification by sex in the association between CPI type and time to CPI-hypophysitis. In particular, anti-CTLA-4 exposed men had a shorter time to onset than women. MRI changes of the pituitary were most common at the time of hypophysitis diagnosis (55.6% enlarged, 37.0% normal, 7.4% empty or partially empty) but persisted in follow-up (23.8% enlarged, 57.1% normal, 19.1% empty or partially empty). HLA typing was done on 55 subjects; HLA type DQ0602 was over-represented in CPI-hypophysitis relative to the Caucasian American population (39.4% vs 21.5%, P = 0.01) and CPI population. The association of CPI-hypophysitis with HLA DQ0602 suggests a genetic risk for its development. The clinical phenotype of hypophysitis appears heterogenous, with differences in timing of onset, changes in thyroid function tests, MRI changes, and possibly sex related to CPI type. These factors may play an important role in our mechanistic understanding of CPI-hypophysitis.

Effect of Ganmai Dazao Decoction on ethology of rats with PTSD and its mechanism

This study aimed to explore the effect of Ganmai Dazao Decoction on the ethology of rats with posttraumatic stress disorder(PTSD) and study the related mechanism through the changes in magnetic resonance imaging and protein expression. Sixty rats were randomly divided into 6 groups, namely the normal group, the model group, the low(1 g·kg~(-1)), medium(2 g·kg~(-1)), and high-dose Ganmai Dazao Decoction groups(4 g·kg~(-1)), and the positive control group(intragastric administration with 10.8 mg·kg~(-1) of fluoxetine), with 10 rats in each group. Two weeks after inducing PTSD by single-prolonged stress(SPS) in rats, the positive control group was given fluoxetine hydrochloride capsule by gavage, the low, medium, and high-dose groups were given Ganmai Dazao Decoction by gavage, and both the normal group and the model group were given the same volume of normal saline by gavage, each for 7 days. The open field experiment, elevated cross elevated maze, forced swimming experiment, and new object recognition test were carried out for the behavioral test. Three rats in each group were selected to detect the expression of neuropeptide receptor Y1(NPY1R) protein in the hippocampus by Western blot. Then, the other three rats in each group were selected to use the 9.4T magnetic resonance imaging experiment to observe the overall structural changes in the brain region and the anisotropy fraction of the hippocampus. The results of the open field experiment showed that the total distance and central distance of rats in the model group were significantly lower than those in the normal group, and the total distance and central distance of rats in the middle and high-dose Ganmai Dazao Decoction groups were higher than those in the model group. The results of the elevated cross maze test showed that medium and high-dose Ganmai Dazao Decoction remarkably increased the number of open arm entries and the residence time of open arm of rats with PTSD. The results of the forced swimming experiment showed that the immobility time in the water of the model group rats was significantly higher than that of the normal group, and Ganmai Dazao Decoction hugely reduced the immobility time in the water of rats with PTSD. The results of the new object recognition test showed that Ganmai Dazao Decoction significantly increased the exploration time of new objects and familiar objects in rats with PTSD. The results of Western blot showed that Ganmai Dazao Decoction significantly reduced the expression of NYP1R protein in the hippocampus of rats with PTSD. The 9.4T magnetic resonance examination found that there was no significant difference in the structural image among the groups. In the functional image, the fractional anisotropy(FA value) of the hippocampus in the model group was significantly lower than that in the normal group. The FA value of the hippocampus in the middle and high-dose Ganmai Dazao Decoction groups was higher than that in the model group. Ganmai Dazao Decoction reduces the injury of hippocampal neurons by inhibiting the expression of NYP1R in the hippocampus of rats with PTSD, thereby improving the nerve function injury of rats with PTSD and playing a neuroprotective role.

Diagnostics of Sacroiliac Joint Differentials to Axial Spondyloarthritis Changes by Magnetic Resonance Imaging.

The diagnosis of axial spondyloarthritis (axSpA) is usually based on a pattern of imaging and clinical findings due to the lack of diagnostic criteria. The increasing use of magnetic resonance imaging (MRI) of the sacroiliac joints (SIJ) to establish the diagnosis early in the pre-radiographic phase has resulted in a shift in the paradigm with an increasing frequency of axSpA diagnoses and a changed sex distribution. Non-radiographic axSpA affects males and females nearly equally, whereas ankylosing spondylitis predominantly occurs in males. The MRI-based increasing frequency of axSpA in women is mainly due to the presence of subchondral bone marrow edema (BME) on fluid-sensitive MR sequences, which may be a non-specific finding in both women and men. Due to the somewhat different pelvic tilt and SIJ anatomy, women are more prone than men to develop strain-related MRI changes and may have pregnancy-related changes. Awareness of non-specific subchondral BME at the SIJ is important as it can imply a risk for an incorrect SpA diagnosis, especially as the clinical manifestations of axSpA may also be non-specific. Knowledge of relevant MRI and clinical features of differential diagnoses is needed in the diagnostic workout of patients with suspected axSpA considering that non-SpA-related SIJ conditions are more common in patients with low back or buttock pain than axSpA sacroiliitis. The purpose of this review was to present current knowledge of the most frequent differential diagnoses to axSpA sacroiliitis by MRI taking the clinical characteristics into account.

Time-course changes in multiparametric magnetic resonance imaging following focal cryotherapy for localized prostate cancer: Initial experience

PurposeTo evaluate the time-course changes of multiparametric MRI findings following focal cryotherapy for localized prostate cancer. MethodsSixteen patients who underwent focal cryotherapy as an initial curative treatment for localized prostate cancer during March 2017–April 2021 were included. Before the treatment, the patients underwent targeted prostate biopsy using MRI–transrectal ultrasound fusion. Overall, 64 MRIs were conducted after focal cryotherapy and the temporal post-treatment MR signal changes of the ablated area in T2WI, T1WI, DWI, and DCE-MRI were analyzed. ResultsTechnical success was achieved in all patients. The median follow-up period was 22 months. The initial post-treatment MRI revealed significant signal changes in the target lesions for all patients, including the disappearance of findings suggestive of cancer. At 3 months post-treatment, most lesions were hyperintense with a hypointense rim on T2WI, T1WI, and DWI (83.3 %). After 6 months, hyperintensity reduced, and after 17 months, all lesions showed hypointensity in these sequences. DCE-MRI of most patients showed loss of internal enhancement; however, one patient exhibited residual nodular enhancement in the ablated area at 3 months, which disappeared after 6 months. Peripheral enhancement was common at 3 months, disappearing after 23 months. Two patients showed biopsy-evidenced local recurrence. The recurrent lesions showed hypointensity on T2WI with diffusion restriction and early contrast enhancement in the ventral transition zone. ConclusionMRI findings of the ablated sites following focal cryotherapy for localized prostate cancer show dynamic signal changes, especially within the first 6 months.

The effects of acupuncture therapy in migraine: An activation likelihood estimation meta-analysis.

Previous functional magnetic resonance imaging studies indicated that acupuncture could activate the brain regions in patients with migraine. However, these studies showed inconsistent results. This activation likelihood estimation (ALE) meta-analysis aimed to investigate the consistent activated change of brain regions between pre- and post-acupuncture treatment in migraineurs. We conducted a literature search in PubMed, Embase, Web of Science, the Cochrane Library, the China National Knowledge Infrastructure, the Chinese Science and Technology Periodical Database, the Wanfang Database, and the Chinese Biomedical Literature Database from their inception to 18 August, 2022, to obtain articles assessing the functional magnetic resonance imaging changes of acupuncture for migraine. Two investigators independently performed literature selection, data extraction, and quality assessment. The methodological quality was assessed with a modified version of the checklist. The reporting quality of interventions among included studies was evaluated by the Revised Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA). Our meta-analysis was conducted according to the GingerALE software. The Jackknife sensitivity analysis was used to assess the robustness of the results. 14 articles were finally included according to the eligible criteria. Regarding the immediate effect of acupuncture on migraine, the ALE meta-analysis demonstrated that the deactivation regions were mainly located in the superior frontal gyrus, and middle frontal gyrus (uncorrected P < 0.001). The ALE meta-analysis of the cumulative effect showed that the activation regions were the thalamus, superior frontal gyrus, posterior lobe of the cerebellum, insula, middle frontal gyrus, precentral gyrus, anterior cingulate, and the deactivation brain regions were located in the transverse temporal gyrus, postcentral gyrus, superior temporal gyrus, anterior cingulate, parahippocampal gyrus, inferior parietal lobule, and inferior occipital gyrus (uncorrected P < 0.001). Acupuncture could activate multiple brain areas related with the regulation of pain conduction, processing, emotion, cognition, and other brain regions in patients with migraine. In the future, the combination of multiple imaging technologies could be a new approach to deeply investigate the central mechanism of acupuncture for migraine.