Magnetic Resonance Imaging Results Research Articles

Association of Total Hip Arthroplasty Flexural Rigidity With Magnetic Resonance Imaging and Histological Findings

BackgroundModular connections in total hip arthroplasty (THA) offer surgical advantages, but can contribute to implant fretting and corrosion due to micromotion at the head–stem interface. Previous studies implicated lower flexural rigidity as a key contributing factor to THA corrosion and fretting, but none associated flexural rigidity with direct histological evaluation or magnetic resonance imaging (MRI) outcomes. The purpose of this study was to determine how implant flexural rigidity is associated with MRI imaging metrics and histopathological outcomes in patients who have a failed THA. MethodsPatients requiring revision THA surgery underwent preoperative MRIs with 3-dimensional multispectral imaging techniques to suppress metal artifacts. The MRI images were graded for adverse local tissue reactions. For each hip, trunnion flexural rigidity was measured from the retrieved femoral stem, and a periprosthetic tissue sample was retrieved and evaluated using semiquantitative histology. Generalized linear models and analyses of variance were used to assess associations between flexural rigidity and MRI and histology outcomes. ResultsA total of 106 THA stems were retrieved (46 women and 60 men, age: 68 years (range, 60 to 73 years). After adjustment for length of implantation, flexural rigidity was negatively correlated with histologic aseptic lymphocyte-dominant vasculitis-associated lesion severity (β = −26.27, P = .018), Fujishiro lymphocyte grading (β = −13.4, P = .039), perivascular lymphocyte layers (β = −17.8, P = .022), the grade of tissue organization (β = −22.5, P = .009), the presence of diffuse synovitis (β = −66.5, P = .003), and the presence of lymphoid aggregates (β = −75.9, P = .022). No association was found between MRI metrics and flexural rigidity. ConclusionsAmong these implants, decreased trunnion stiffness was associated with increased histologic features of adverse host-mediated soft tissue reactions.

Radiology diagnostics of spinal corel injury in early children: a prospective study

INTRODUCTION: Spinal cord injury (SCI) in young children includes a relatively higher prevalence of cervical spine injury, multiple thoracic vertebral compression fractures, and spinal cord injury. Spinal cord injuries without radiological changes/signs of fractures or dislocations (SCIWORA) also occur in young children. X-ray assessment of damage to immature vertebrae and cartilage in young children is difficult, since incompletely formed vertebral bodies can be confused with fractures. Accordingly, an MRI is required, which provides a detailed anatomical image of all structures of the spinal column and also diagnoses damage to the spinal cord, ligaments and muscles.OBJECTIVE: To investigate the possibilities of methods of radiation diagnosis of spinal cord injury in young children (up to 3 years).MATERIAL AND METHODS: 20 children aged from 11 months up to 3 years old were studied with spinal cord injury. X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. The standard MRI protocol for SCI in children under 3 years of age included: MR myelography in the coronary and sagittal projections, sagittal projection STIR, DTI and T2WI FS SE, axial projection T2WI FS SE or T2*WI FS GE; coronary projection T2WI SE; 3D T1WI FS GE before and after contrast enhancement.RESULTS: An analysis of the data of patients included in the category of polytrauma was carried out. The causes of SCI in these patients were road accidents and falls from various heights. X-ray and CT scans were uninformative, and had large discrepancies with MRI results. All anatomical and morphological changes revealed by MRI correlated well with clinical manifestations and corresponded to the classification of the level and severity of spinal cord injury (ASIA). An increase in the volume and change in the signal of the spinal cord due to edema and / or hemorrhage in the spinal cord is the main sign of damage to the spinal cord, and is best indicated on T2WI and STIR, as a hyperintense signal.DISCUSSION: MRI is critical in the emergency assessment of spinal cord injury or compression to predict the outcome of SCI. There is currently no spinal cord imaging technique that can compete with MRI. Increased volume and signal changes in the spinal cord due to edema and/or hemorrhage are a sign of spinal cord injury and are best demonstrated on T2WI and STIR as a hyperintense signal. Incomplete spinal cord injury is also manifested by a hyperintense signal on T2WI and/or FLAIR, which in intensity and extent correlates with the degree of injury. Hemorrhagic injuries are better detected using T2*GRE or SWI, and spinal cord edema is better detected using T2WI SE and STIR. In addition, STIR can identify bone marrow edema in injured vertebrae, even when the injury is not detected on CT.CONCLUSION: When performing MRI in patients with SCI, three quantitative parameters should be assessed: the maximum damage to the spinal cord, the maximum compression of the spinal cord, and the length of the affected area. In addition to the results of quantitative parameters, potential predictive qualitative MRI findings should be evaluated such as intramedullary hemorrhage, focal and diffuse spinal cord edema, soft tissue injury, probable stenosis before injury, and disc herniation.

Superparamagnetic Nanoparticles with Phosphorescent Complexes as Hybrid Contrast Agents: Integration of MRI and PLIM

Two different hybrid nanosystems are prepared by loading highly crystalline, monodisperse magnetite nanocubes (MNCs) with phosphorescent Pt(II) complexes (PtCxs). One involves the encapsulation of the hydrophobic PtCx1 within an amphiphilic comb polymer (MNC@poly(maleic anhydride‐alt‐1‐octadecene) [PMAO]–PtCx1), whereas the other involves the direct binding of the hydrophilic PtCx2 to the surface of the MNC mediated by a ligand‐exchange procedure (MNC@OH–PtCx2). Both systems are evaluated as potential candidates for multimodal imaging in magnetic resonance imaging (MRI) and photoluminescence lifetime imaging micro(spectro)scopy (PLIM). PLIM measurements on agarose phantoms demonstrate significantly longer excited‐state lifetimes compared to the short‐lived autofluorescence of biological background. Additionally, both nanosystems perform as effective MRI contrast agents (CAs): the r2* values are 3–4 times higher than for the commercial CA ferucarbotran. MNC@PMAO–PtCx1 particles also cause significant increases in r2. While the ligand exchange procedure efficiently anchors PtCxs to the MNC surface, the polymeric encapsulation ensures higher colloidal stability, contributing to differences in PLIM and MRI outcomes. In these results, the successful integration of two complementary noninvasive imaging modalities within a single nanosystem is confirmed, serving as the impetus for further investigation of such systems as advanced multimodal–multiscale imaging agents with dual orthogonal readouts.

A toolkit for stroke infarct volume estimation in rodents

Stroke volume is a key determinant of infarct severity and an important metric for evaluating treatments. However, accurate estimation of stroke volume can be challenging, due to the often confined 2-dimensional nature of available data. Here, we introduce a comprehensive semi-automated toolkit to reliably estimate stroke volumes based on (1) whole brains ex-vivo magnetic resonance imaging (MRI) and (2) brain sections that underwent immunofluorescence staining. We located and quantified infarct areas from MRI three days (acute) and 28 days (chronic) after photothrombotic stroke induction in whole mouse brains. MRI results were compared with measures obtained from immunofluorescent histologic sections of the same brains. We found that infarct volume determined by post-mortem MRI was highly correlated with a deviation of only 6.6 % (acute) and 4.9 % (chronic) to the measurements as determined in the histological brain sections indicating that both methods are capable of accurately assessing brain tissue damage (Pearson r > 0.9, p < 0.001). The Dice similarity coefficient (DC) showed a high degree of coherence (DC > 0.8) between MRI-delineated regions of interest (ROIs) and ROIs obtained from histologic sections at four to six pre-defined landmarks, with histology-based delineation demonstrating higher inter-operator similarity compared to MR images. We further investigated stroke-related scarring and post-ischemic angiogenesis in cortical peri‑infarct regions and described a negative correlation between GFAP+fluorescence intensity and MRI-obtained lesion size.

Clinical Values of Whole-Body Blood Pool Scans and SPECT for Evaluation of Congenital Vascular Malformation.

This study examines the diagnostic potential of whole-body blood pool scintigraphy (WBBPS) using technetium-99m-labeled red blood cells to detect congenital vascular malformations (CVMs). It aims to compare its efficacy with traditional imaging techniques such as magnetic resonance imaging (MRI) and ultrasonography (USG), emphasizing its potential advantages in terms of characterization of lesions and capacity for whole-body assessment. The efficacy of WBBPS and single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging in diagnosing CVMs, comparing them with USG and MRI results, was evaluated in this retrospective study. Of the 38 patients, 21 were evaluated using these diagnostic methods, with CVMs classified according to the International Society for the Study of Vascular Anomalies guidelines. Also, this study aimed to elucidate the characteristics between WBBPS, SPECT/CT, USG, or MRI findings and their consistency with the final diagnosis. A total of 21 participants were included in this study, with an average age of 17.7 years old, with female predominance (57.1%). The most common diagnosis was vascular malformations (VMs) (71.4%), followed by combined vascular malformations (14.3%) and lymphatic malformations (9.5%). WBBPS demonstrated positive results in 95.2% of cases. Distinct imaging patterns for each condition were observed, with WBBPS being crucial in locating lesions. The study findings suggested that WBBPS with SPECT/CT could be helpful in detecting occult VM lesions and ruling out a lymphatic malformation diagnosis. Thus, it can be employed in the evaluation of CVMs.

Analysis of the indications for and results of breast cancer screening by magnetic resonance imaging at a cancer center in Brazil.

To evaluate the indications for and results of magnetic resonance imaging (MRI) examinations for breast cancer screening at a cancer center in Brazil. This was a retrospective observational study, based on electronic medical records, of patients undergoing MRI for breast cancer screening at a cancer center in Brazil. We included 597 patients between 19 and 82 years of age. The main indications for MRI screening were a personal history of breast cancer, in 354 patients (59.3%), a family history of breast cancer, in 102 (17.1%), and a confirmed genetic mutation, in 67 (11.2%). The MRI result was classified, in accordance with the categories defined in the Breast Imaging Reporting and Data System, as benign (category 1 or 2), in 425 patients (71.2%), probably benign (category 3), in 143 (24.0%), or suspicious (category 4 or 5), in 29 (4.9%). On MRI, 11 malignant tumors were identified, all of which were invasive carcinomas. Among those 11 carcinomas, six (54.5%) were categorized as minimal cancers (< 1 cm), and the axillary lymph nodes were negative in 10 (90.9%). The cancer detection rate was 18.4/1,000 examinations, and the positive predictive value for suspicious lesions submitted to biopsy was 37.9%. In our sample, the main indication for breast MRI screening was a personal history of breast cancer. The results indicate that MRI is a highly accurate method for the early detection of breast neoplasms in this population.

Cladribine tablets after treatment with natalizumab (CLADRINA) - rationale and design.

Individual disease modifying therapies approved for multiple sclerosis (MS) have limited effectiveness and potentially serious side effects, especially when administered over long periods. Sequential combination therapy is a plausible alternative approach. Natalizumab is a monoclonal therapeutic antibody that reduces leukocyte access to the central nervous system that is associated with an increased risk of progressive multifocal leukoencephalopathy and disease reactivation after its discontinuation. Cladribine tablets act as a synthetic adenosine analog, disrupting DNA synthesis and repair, thereby reducing the number of lymphocytes. The generation of prospective, rigorous safety, and efficacy data in transitioning from natalizumab to cladribine is an unmet clinical need. To test the feasibility of transitioning patients with relapsing forms of MS natalizumab to cladribine tablets. Cladribine tablets after treatment with natalizumab (CLADRINA) is an open-label, single-arm, multicenter, collaborative phase IV, research study that will generate hypothesis regarding the safety, efficacy, and immunological impact of transition from natalizumab to cladribine tablets in patients with relapsing forms of MS. Participants will be recruited from three different sites. The primary endpoint is the absolute and percent change from baseline of lymphocytes and myeloid cell subsets, as well as blood neurofilament light levels. The secondary endpoint is the annualized relapse rate over the 12- and 24-month trial periods. Exploratory endpoints include the expanded disability status scale, and magnetic resonance imaging outcomes. The CLADRINA trial will generate data regarding the safety, efficacy, and immunological impact of the transition from natalizumab to cladribine. As the pace of immunological knowledge of MS continues, insight into disease modifying therapy transition strategies is needed.

Pulmonary Hypertension: Intensification and Personalization of Combination Rx (PHoenix): A phase IV randomized trial for the evaluation of dose-response and clinical efficacy of riociguat and selexipag using implanted technologies.

Approved therapies for the treatment of patients with pulmonary arterial hypertension (PAH) mediate pulmonary vascular vasodilatation by targeting distinct biological pathways. International guidelines recommend that patients with an inadequate response to dual therapy with a phosphodiesterase type-5 inhibitor (PDE5i) and endothelin receptor antagonist (ERA), are recommended to either intensify oral therapy by adding a selective prostacyclin receptor (IP) agonist (selexipag), or switching from PDE5i to a soluble guanylate-cyclase stimulator (sGCS; riociguat). The clinical equipoise between these therapeutic choices provides the opportunity for evaluation of individualized therapeutic effects. Traditionally, invasive/hospital-based investigations are required to comprehensively assess disease severity and demonstrate treatment benefits. Regulatory-approved, minimally invasive monitors enable equivalent measurements to be obtained while patients are at home. In this 2 × 2 randomized crossover trial, patients with PAH established on guideline-recommended dual therapy and implanted with CardioMEMS™ (a wireless pulmonary artery sensor) and ConfirmRx™ (an insertable cardiac rhythm monitor), will receive ERA + sGCS, or PDEi + ERA + IP agonist. The study will evaluate clinical efficacy via established clinical investigations and remote monitoring technologies, with remote data relayed through regulatory-approved online clinical portals. The primary aim will be the change in right ventricular systolic volume measured by magnetic resonance imaging (MRI) from baseline to maximal tolerated dose with each therapy. Using data from MRI and other outcomes, including hemodynamics, physical activity, physiological measurements, quality of life, and side effect reporting, we will determine whether remote technology facilitates early evaluation of clinical efficacy, and investigate intra-patient efficacy of the two treatment approaches.

Association Between MRI Findings of Facet Arthropathy and Synovitis With Health-Related Outcome and Pain Scores Following Therapeutic Lumbar Facet Injections.

Low back pain is a common complaint among adults. The facet joint is a major source of lumbar pain, and therapeutic facet injections have gained popularity as a minimally invasive treatment option. In addition, magnetic resonance imaging (MRI) utilization for diagnosing low back pain has increased significantly over the past few decades. Facet synovitis is an entity characterized by edema and inflammatory changes affecting the facet joints, adjacent bone marrow, and surrounding soft tissues. Although its underlying etiology remains poorly understood, recent reports suggest a high incidence in patients with arthropathy and arthritis. It is essential to explore potential correlations between specific MRI findings and outcomes after lumbar facet injections. This investigation is particularly relevant for facet synovitis, given its inflammatory nature and the common use of anti-inflammatory agents in facet injections. We investigated associations between MRI evidence of facet arthropathy and/or synovitis and the degree of improvement in health-related outcome and pain scores after therapeutic facet injections. The review was conducted on patients who received bilateral therapeutic facet injections, excluding those with prior lumbar spinal surgery or transitional segments. Facet arthropathy and synovitis were assessed on MRI by two neuroradiologists, and postprocedure outcomes such as pain and function were compared using univariate and multivariate analyses based on MRI findings. Our retrospective review indicates that patients receiving facet injections experience greater mean reduction in daily activity and workability burden scores from back pain when facet synovitis is a known portion of their pathology. The authors pose that further study could help identify patient populations that are the best candidates for therapeutic intervention. This may ultimately improve delivery of care, cost efficacy, and patient satisfaction.

Augmentation with Bone Marrow Aspirate Harvested from the Iliac Crest for Horizontal or Radial Meniscal Tears Yields Favorable Healing Rates in Magnetic Resonance Imaging and Clinical Outcomes

Augmentation with Bone Marrow Aspirate Harvested from the Iliac Crest for Horizontal or Radial Meniscal Tears Yields Favorable Healing Rates in Magnetic Resonance Imaging and Clinical Outcomes

Clinical presentation, magnetic resonance imaging findings, and outcome of 80 Dachshunds with cervical intervertebral disc extrusion.

Large clinical studies regarding cervical intervertebral disc extrusion (IVDE) in Dachshunds are lacking. This retrospective multicentric study therefore aims to describe the clinical features, magnetic resonance imaging (MRI) findings and outcomes of Dachshunds diagnosed with cervical IVDE. Medical records of Dachshunds with cervical IVDE were reviewed for signalment, onset of clinical signs, neurological examination, MRI features, treatment and outcome. Eighty Dachshunds were included in the study, mostly ambulatory (55% grade 1 and 33% grade 2) and without nerve root signature (85% of cases) on presentation. Information on coat type was available for 56% of dogs; specifically, 41% were smooth-haired, 9% were long-haired and 6% were wire-haired Dachshunds. There were 29 (36%) neutered female, 27 (34%) male entire, 15 (19%) male neutered and 9 (11%) entire female dogs. The onset of clinical signs was most often >48 h (84%). The most common intervertebral disc space affected was C2-C3 (38%) and foraminal IVDEs were reported in 14% of dogs. A foraminal IVDE was diagnosed in only 25% of dogs presented with nerve root signatures. Most dogs (77.5%) were treated surgically. In this group, a higher body condition score on presentation and a higher mean spinal cord compression ratio calculated on MRI were directly and moderately associated with a longer hospitalization time (r = 0.490 p = 0.005 and r = 0.310 p = 0.012, respectively). The recovery time was longer in dogs with an onset of clinical signs <24 h or 24-48 h compared to those with an onset of clinical signs >48 h (3.1 ± 6.5 days versus 1.6 ± 6.2, p < 0.001) in both medically and surgically treated groups. Data about the outcome was available for 83% of dogs. Eighty percent of the entire population of dogs was considered to have completely returned to normal. There was no association between the therapeutic choice (surgical versus medical management) and the outcome of the dogs included in this study.

Neoadjuvant Chemotherapy and Neoadjuvant Chemotherapy with Immunotherapy Result in Defferent Tumor Shrinkage Patterns in Triple-negative Breast Cancer.

This study aims to explore whether neoadjuvant chemotherapy with immunotherapy (NACI) leads to different tumor shrinkage patterns, based on magnetic resonance imaging (MRI), compared to neoadjuvant chemotherapy (NAC) alone in patients with triple-negative breast cancer (TNBC). Additionally, the study investigates the relationship between tumor shrinkage patterns and treatment efficacy was investigated. This retrospective study included patients with TNBC patients receiving NAC or NACI from January 2019 until July 2021 at our center. Pre- and post-treatment MRI results were obtained for each patient, and tumor shrinkage patterns were classified into three categories as follows: 1) concentric shrinkage (CS); 2) diffuse decrease; and 3) no change. Tumor shrinkage patterns were compared between the NAC and NACI groups, and the relevance of the patterns to treatment efficacy was assessed. Of the 99 patients, 65 received NAC and 34 received NACI. The CS pattern was observed in 53% and 20% of patients in the NAC and NACI groups, respectively. Diffuse decrease pattern was observed in 36% and 68% of patients in the NAC and NACI groups. The association between the treatment regimens (NAC and NACI) and tumor shrinkage patterns was statistically significant (p=0.004). The postoperative pathological complete response (pCR) rate was 45% and 82% in the NAC and NACI groups (p<0.001), respectively. In the NACI group, 17% of patients with the CS pattern and 56% of those with the diffuse decrease pattern achieved pCR (p=0.903). All tumor shrinkage patterns were associated with achieved a high pCR rate in the NACI group. Our study demonstrates that the diffuse decrease pattern of tumor shrinkage is more common following NACI than that following NAC. Furthermore, our findings suggest that all tumor shrinkage patterns are associated with a high pCR rate in patients with TNBC treated with NACI.

BrainNet: A Deep Learning Approach for Brain Tumor Classification

Cancer, regardless of its type, represents a formidable threat to human life and disrupts the delicate balance of normal bodily functions. Among the various forms of cancer, malignant brain tumors stand out as a leading cause of mortality in both adult and pediatric populations. The timely identification of these brain tumors is crucial for attaining precise diagnoses. Brain tumour identification and diagnosis are now made possible by the use of magnetic resonance imaging (MRI). However, the intricate and irregular shapes and locations of these tumors often pose challenges for complete comprehension. Typically, the expertise of neurosurgical specialists is required for the precise analysis of MRI scans. Unfortunately, in many developing countries, a shortage of skilled medical professionals and limited awareness about brain tumors compound the difficulties associated with obtaining timely and accurate MRI results. To address these notable challenges, this research introduces BrainNet, an innovative Convolutional Neural Network (CNN) architecture specifically designed for the classification of brain tumors into distinct categories. The established transfer learning models VGG13, VGG19, VGG16, InceptionResV2, and Squeeznet, all of which were pretrained on the Imagenet dataset, are outperformed by BrainNet in both how well it handles these problems and how well it outperforms them. The performance of the BrainNet CNN architecture is particularly impressive, with a precision score of 94.75 percent and accuracy rates of 99.96 percent during training and 97.71 percent during testing. This accomplishment has the potential to significantly improve brain tumour diagnosis and classification, particularly in areas with limited access to medical resources and knowledge.

Newly discovered variants in unexplained neonatal encephalopathy.

The genetic background of neonatal encephalopathy (NE) is complicated and early diagnosis is beneficial to optimizing therapeutic strategy for patients. NE Patients with unclear etiology received regular clinical tests including ammonia test, metabolic screening test, amplitude-integrated electroencephalographic (aEEG) monitoring, brain Magnetic Resonance Imaging (MRI) scanning, and genetic test. The protein structure change was predicted using Dynamut2 and RoseTTAFold. 15 out of a total of 113 NE Patients were detected with newly reported pathogenic variants. In this sub-cohort, (1) seizure was the primary initial symptoms; (2) four patients had abnormal metabolic screening results, and two of them were also diagnosed with excessive blood ammonia concentration; (3) the brain MRI results were irregular in three infants and the brain waves were of moderate-severe abnormality in about a half of the patients. The novel pathogenic variants discovered in this study belonged to 12 genes, and seven of them were predicted to introduce a premature translation termination. In-silicon predictions showed that four variants were destructive to the protein structure of KCNQ2. Our study expands the mutation spectrum of genes associated with NE and introduces new evidence for molecular diagnosis in this newborn illness.

Neoadjuvant Chemotherapy and Neoadjuvant Chemotherapy With Immunotherapy Result in Different Tumor Shrinkage Patterns in Triple-Negative Breast Cancer.

This study aims to explore whether neoadjuvant chemotherapy with immunotherapy (NACI) leads to different tumor shrinkage patterns, based on magnetic resonance imaging (MRI), compared to neoadjuvant chemotherapy (NAC) alone in patients with triple-negative breast cancer (TNBC). Additionally, the study investigates the relationship between tumor shrinkage patterns and treatment efficacy was investigated. This retrospective study included patients with TNBC patients receiving NAC or NACI from January 2019 until July 2021 at our center. Pre- and post-treatment MRI results were obtained for each patient, and tumor shrinkage patterns were classified into three categories as follows: 1) concentric shrinkage (CS); 2) diffuse decrease; and 3) no change. Tumor shrinkage patterns were compared between the NAC and NACI groups, and the relevance of the patterns to treatment efficacy was assessed. Of the 99 patients, 65 received NAC and 34 received NACI. The CS pattern was observed in 53% and 20% of patients in the NAC and NACI groups, respectively. Diffuse decrease pattern was observed in 36% and 68% of patients in the NAC and NACI groups. The association between the treatment regimens (NAC and NACI) and tumor shrinkage patterns was statistically significant (p = 0.004). The postoperative pathological complete response (pCR) rate was 45% and 82% in the NAC and NACI groups (p < 0.001), respectively. In the NACI group, 17% of patients with the CS pattern and 56% of those with the diffuse decrease pattern achieved pCR (p = 0.903). All tumor shrinkage patterns were associated with achieved a high pCR rate in the NACI group. Our study demonstrates that the diffuse decrease pattern of tumor shrinkage is more common following NACI than that following NAC. Furthermore, our findings suggest that all tumor shrinkage patterns are associated with a high pCR rate in patients with TNBC treated with NACI. ClinicalTrials.gov Identifier: NCT04909554.

Evaluation of the accuracy of an augmented reality-based tumor-targeting guide for breast-conserving surgery

Background and ObjectivesAlthough magnetic resonance imaging (MRI) is commonly used for breast tumor detection, significant challenges remain in determining and presenting the three-dimensional (3D) morphology of tumors to guide breast-conserving surgery. To address this challenge, we have developed the augmented reality-breast surgery guide (AR-BSG) and compared its performance with that of a traditional 3D-printed breast surgical guide (3DP-BSG). MethodsBased on the MRI results of a breast cancer patient, a breast phantom made of skin, body, and tumor was fabricated through 3D printing and silicone-casting. AR-BSG and 3DP-BSG were executed using surgical plans based on the breast phantom's computed tomography scan images. Three operators independently inserted a catheter into the phantom using each guide. Their targeting accuracy was then evaluated using Bland–Altman analysis with limits of agreement (LoA). Differences between the users of each guide were evaluated using the intraclass correlation coefficient (ICC). ResultsThe entry and end point errors associated with AR-BSG were −0.34±0.68 mm (LoA: −1.71–1.01 mm) and 0.81±1.88 mm (LoA: −4.60–3.00 mm), respectively, whereas 3DP-BSG was associated with entry and end point errors of −0.28±0.70 mm (LoA: −1.69–1.11 mm) and −0.62±1.24 mm (LoA: −3.00–1.80 mm), respectively. The AR-BSG's entry and end point ICC values were 0.99 and 0.97, respectively, whereas 3DP-BSG was associated with entry and end point ICC values of 0.99 and 0.99, respectively. ConclusionsAR-BSG can consistently and accurately localize tumor margins for surgeons without inferior guiding accuracy AR-BSG can consistently and accurately localize tumor margins for surgeons without inferior guiding accuracy compared to 3DP-BSG. Additionally, when compared with 3DP-BSG, AR-BSG can offer better spatial perception and visualization, lower costs, and a shorter setup time.

Postoperative hypernatremia is associated with worse brain injuries on EEG and MRI following pediatric cardiac surgery.

Dysnatremia is a common electrolyte disturbance after cardiopulmonary bypass (CPB) surgery for congenital heart disease (CHD) and a known risk factor for adverse neurological events and clinical outcomes. The objective of this study was to evaluate the association of dysnatremia with worse abnormal EEG patterns, brain injuries detected by magnetic resonance imaging (MRI) and early adverse outcomes. We monitored continuous EEG in 340 children during the initial 48 h following cardiac surgery. Demographics and clinical characteristics were recorded. Sodium concentrations were measured in the arterial blood gas analysis every 6 h. Hyponatremia and hypernatremia were classified by the average of sodium concentrations over 48 h. Postoperative cerebral MRI was performed before hospital discharge. In our patient cohort, dysnatremia was present in 46 (13.5%) patients. Among them, hyponatremia occurred in 21 (6.2%) and hypernatremia in 25 (7.4%). When compared to patients with normonatremia, hyponatremia was not associated with EEG abnormalities and early adverse outcomes (Ps ≥ .14). In hypernatremia group, the CPB time was significantly longer and more frequent use of DHCA (Ps ≤ .049). After adjusting for time, CPB time and the use of DHCA, hypernatremia was significantly associated with worse EEG abnormalities (including background, seizures and pathological delta brushes), more severe brain injuries on MRI (Ps ≤ .04) and trended to be associated with longer postoperative mechanical ventilation time (P = .06). Hypernatremia and hyponatremia were common in children after cardiac surgery. Hypernatremia, but not hyponatremia, was significantly associated with worse EEG abnormalities and more severe brain injuries on MRI and extended postoperative mechanical ventilation time.

Brain magnetic resonance imaging as predictors in pediatric anti-N-methyl-D-aspartate receptor encephalitis

ObjectiveTo investigate the associations between brain magnetic resonance imaging (MRI) changes and clinical profiles in children with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. MethodsClinical data and brain MRI results of children diagnosed with anti-NMDAR encephalitis in Guangzhou Women and Children's Medical Center from October 2014 to June 2022 were retrospectively studied. ResultsA total of 143 children (Male: female 54:89) were enrolled, with a mean onset age of 6.8 years (6.8 ± 3.1). 40.6 % (58/143) of patients had abnormal initial brain MRI. Lesions in temporal lobe (34.5 %, 20/58) and frontal lobe (25.9 %, 15/58) were relatively common. Children with abnormal initial brain MRI were prone to have fever (P = 0.023), dystonia (P = 0.037), positive MOG antibodies (P = 0.015), higher cerebrospinal fluid (CSF) white blood cell count (WBC) (P = 0.019) and to receive rituximab treatment (P = 0.037). There were no significant differences in modified Rankin Scale (mRS) scores before immunotherapy, after immunotherapy and at last follow-up between the normal initial brain MRI group and abnormal group. No initial brain MRI changes were found to be associated with relapses. Brain MRI was reviewed in 72 patients at last follow-up with a median follow-up time of 25.5 months and 48.6 % (35/72) of patients had abnormal brain MRI. The mRS score of the group with normal brain MRI at last follow-up was significantly lower than that of the abnormal group. ConclusionsAbout 40.0 % of children with anti-NMDAR encephalitis had abnormal initial brain MRI. Initial brain MRI was associated with certain clinical profiles, but not with relapse and prognosis. Around half of patients had abnormal brain MRI at last follow-up and were prone to have higher mRS score.

Dissociation of clinical symptoms and magnetic resonance imaging data in axial psoriatic arthritis

Currently, there is no generally accepted definition of axial lesions in psoriatic arthritis (axPsA), and the diagnostic criteria are extrapolated from the recommendations for ankylosing spondylitis and axial spondyloarthritis.Objective: To evaluate data of magnetic resonance imaging (MRI) of spine and sacroiliac joints (SIJ) in patients with psoriasis complaining of chronic back pain of any cause.Material and methods. 143 patients were enrolled to the study, including 57 (39.9%) men and 86 (60.1%) women, median age – 47 [36; 57] years, mean duration of psoriasis was 17.4±13.4 years. In all patients, the agreement of the existing symptoms with the inflammatory back pain (IBP) criteria of A. Calin et al., M. Rudwaleit et al. and ASAS was checked. All patients underwent MRI of the spine and SIJ, determination of ESR, CRP levels, HLA-B27 and consultations with a dermatologist and a rheumatologist.Results and discussion. An association of bone marrow edema (BME) in the spine and SIJ with nail involvement (odds ratio, OR 2.32; 95% confidence interval, CI 1.12–4.81; p=0.035), palmoplantar psoriasis (OR 3.85; 95% CI 1.43–10.41; p=0.054) and a weak correlation with PASI (r=0.329, p=0.034) was found. There were no statistically significant differences in PASI between patients with BME and without BME. In patients with IBP who fulfilled the criteria of A. Calin et al., osteitis in the SIJ was present in 19 (34.5%; OR 2.79; 95% CI 1.26–6.19; p=0.01); Berlin criteria of 4 signs – 25 (28.7%; OR 2.42; 95% CI 1.00–5.84; p=0.045); Berlin criteria of 3 signs – in 18 (24.0%; OR 1.12; 95% CI 0.51–2.44; p=0.783); ASAS criteria – in 17 (34.0%; OR 2.48; 95% CI 1.12–5.49; p=0.023). In almost half of the patients with BME in the spine or SIJ, the symptoms did not fulfil the criteria for IBP. Signs such as the presence and duration of morning stiffness had a high prognostic value. Isolated spondylitis (presence of BME in vertebrae and absence of BME in SIJ) was rarely found in patients with IBP fulfilling various criteria (in 4.0–8.1% of cases).Conclusion. Considering the existing discrepancy between symptoms and MRI results, it is necessary to develop independent tools for screening and early diagnosis of axPsA.

Association of Knee Osteoarthritis and Flexion Contracture With Localized Tibial Articular Cartilage Loss: Data From the Osteoarthritis Initiative.

To evaluate whether a knee flexion contracture (FC) was associated with localized tibial articular cartilage loss over a 1-year period using Osteoarthritis Initiative quantitative data. Five hundred seventy-eight participants from a previously established nested case-control study of people with radiographic knee OA with or without progression, based on radiographs and symptoms, had their knee range of extension measured at baseline and received magnetic resonance imaging (MRI) at baseline and 1 year. The tibial articular cartilage of the medial and lateral condyles was segmented into anterior, center, and posterior regions. We tested for associations between knee FC (defined as lack of extension to 0°), and localized changes in tibial articular cartilage thickness or percent of denuded bone (0 mm thickness) after 1 year relative to baseline using ANOVA, controlling for baseline MRI outcomes and clinical factors. Knee FC was associated with denuded bone in the medial condyle center (β 0.44, 95% CI 0.02-0.86) and preserved cartilage thickness in the medial condyle posterior (β 0.01, 95% CI 0.002-0.03) regions. Knee FC unloading the tibial center region and loading the posterior region was associated with localized articular cartilage loss centrally and preserved articular cartilage posteriorly. These findings are consistent with knee FC negatively affecting unloaded tibial articular cartilage.