Distinct Imaging Features Research Articles

MRI findings of newly present benign focal hepatic observations following chemotherapy: distinct features in early- and late-term follow-up.

To evaluate gadoxetic acid-enhanced (Gd-EOB-DTPA) MRI features of newly detected benign focal hepatic observations after chemotherapy. In this retrospective single-center case-control study, we enrolled a cohort of 43 cancer patients with 93 newly detected benign focal hepatic observations after chemotherapy between January 2010 and December 2020. We evaluated several parameters including the delay of occurrence after chemotherapy, imaging features, and imaging follow-up. These parameters were compared with those observed in a control group comprising 34 patients with 93 hepatic metastases. For focal hepatic observations occurring at early-term follow-up (delay of occurrence after chemotherapy, median 3 months, range 1-6 months) with 22 patients encompassing 45 lesions, most lesions exhibited an ill-defined margin on HBP images (64.4%), negative on diffusion-weighted images (84.4%), mottled hypo-intensity on hepatobiliary phase images (88.9%), and undistorted vessels traversing the lesions (80.0%). Follow-up imaging indicated that 91.9% of these lesions resolved within 4-20 months. For focal hepatic observations occurring at late-term follow-up (delay of occurrence after chemotherapy, median 34 months, range 12-60 months) with 21 patients encompassing 48 lesions, which were diagnosed as focal nodular hyperplasia (FNH)-like lesions based on MRI features. A hepatobiliary ring enhancement was observed in 56.3% of lesions, and 66.7% of patients showed an increase in lesion size and/or number during follow-up imaging. Focal hepatic observations occurring at early-term and late-term follow-ups after chemotherapy have distinctive imaging features at Gd-EOB-DTPA-MRI. Early-term focal observations tend to resolve spontaneously, whereas FNH-like lesions can increase in size and number during follow-up. Question Focal benign liver lesions related to chemotherapy-induced hepatic injury were reported in recent years, often leading to confusion with metastasis and resulting in misdiagnosis. Findings Chemotherapy-induced focal hepatic observations identified during early- and late-term follow-up exhibit distinct imaging characteristics on Gd-EOB-DTPA-MRI and demonstrate varying temporal changes. Clinical relevance Chemotherapy-induced hepatic observations can be differentiated from metastasis based on Gd-EOB-DTPA MRI findings and their temporal changes. A deeper understanding of their findings can avoid unnecessary biopsies or surgical resections.

A Multicenter Study on Hepatocellular Adenomas in Korea: Clinicopathological and Imaging Features With an Emphasis on β-Catenin Mutated Subtype.

The clinicopathologic and imaging features of hepatocellular adenomas (HCAs) in Asian population remain unclear. We aimed to analyse clinicopathologic and imaging features of HCAs in Korea and propose an imaging-based method to differentiate β-catenin mutated HCA (βHCA) from other subtypes. This retrospective multicenter study included pathologically confirmed HCAs from three tertiary institutions in Korea between 2010 and 2023. HCA subtypes were determined according to the current World Health Organization classification using immunohistochemical staining. Two abdominal radiologists reviewed computed tomography and magnetic resonance imaging scans. The clinical characteristics and imaging features of HCA subtypes were compared. A scoring system for βHCA was developed and validated using development (January 2010-April 2021) and validation (May 2021-March 2023) cohorts. 121 patients (47 men; mean age, 39.0 years ±13.5) with 138 HCAs were included. HCAs displayed characteristic clinicopathologic features, including a high proportion of male (38.8%) and obese patients (35.5%), with the inflammatory subtype being the most common (38.4%) and a low percentage of patients using oral contraceptive (5.0%). Each HCA subtype demonstrated distinct clinical and imaging features. The scoring system incorporating tumour heterogeneity and iso to high hepatobiliary phase signal intensity on MRI for differentiating βHCA exhibited high performance in both the development (AUC 0.92, 95% CI: 0.87-0.97) and the validation cohort (AUC 0.91, 95% CI: 0.77-1.00). This comprehensive analysis of clinicopathologic and imaging features of HCAs in Korea contributes to the characterisation of HCAs across different geographical regions. The imaging-based scoring system effectively differentiates βHCA.

Imaging manifestations and misdiagnosis of liposclerosing myxofibroma fumor

To focus on the imaging features of liposclerosing myxofibrous tumor (LSMFT) and diagnostic challenges to enhance clinical recognition and differential diagnosis accuracy. Retrospective analysis was conducted on the imaging and pathological data from 21 cases diagnosed with LSMFT between January 2014 and November 2022, including 14 males and 7 females (aged from 21 to 73 years; the course of disease ranged from 4 to 48 months). Patient demographics, clinical presentations, and imaging modalities including X-ray, CT, and MRI were reviewed. Pathological findings were correlated with imaging features to delineate diagnostic criteria and identify causes of misdiagnosis. All 21 patients represented primary lesions, located in 14 bilateral femurs [9 on the right and 5 on the left; 12 proximal femurs (intertrochanteric and peripheral) and 2 distal femurs], 2 proximal tibia, 2 proximal humerus, 1 proximal radius, and 1 ilium and 1 calcaneus. On X-ray and CT, all lesions showed cartographical or quasi-circular osteolytic destruction with distinct and sclerotic margins, continuous bone cortex, absence of periosteal reaction and surrounding soft tissue mass. Calcification, bone ridge and varying degrees of fat components were observed in 16 lesions, displaying mixed density;5 lesions showed ground-glass density with minimal bone ridge. On MRI, the signal intensity of the lesion was heterogeneous. T1-weighted imaging showed iso-to slightly high signal intensity, while T2-weighted imaging demonstrated unevenly high signal intensity. Fat-suppressed sequences depicted significantly elevated signal intensity within lesions, with post-contrast enhancement showing uneven patterns. 5 Cases were initially misdiagnosed as fibrous dysplasia. LSMFT is an uncommon benign bone tumor, typically localized in the proximal femur but occasionally found in other skeletal sites. Understanding its distinct imaging characteristics is crucial for accurate diagnosis. Typical cases exhibit identifiable imaging patterns, whereas atypical presentations may lead to misdiagnosis as fibrous dysplasia.

Advanced imaging reveals enhanced malignancy in glioblastomas involving the subventricular zone: evidence of increased infiltrative growth and perfusion.

Glioblastoma's infiltrative growth and heterogeneity are influenced by neural, molecular, genetic, and immunological factors, with the precise origin of these tumors remaining elusive. Neurogenic zones might serve as the tumor stem cells' nest, with tumors in contact with these zones exhibiting worse outcomes and more aggressive growth patterns. This study aimed to determine if these characteristics are reflected in advanced imaging, specifically diffusion and perfusion data. In this monocentric retrospective study, 137 glioblastoma therapy-naive patients (IDH-wildtype, grade 4) with advanced preoperative MRI, including perfusion and diffusion imaging, were analyzed. Tumors and neurogenic zones were automatically segmented. Advanced imaging metrics, including cerebral blood volume (CBV) from perfusion imaging, tissue volume mask (TVM), and free water corrected fractional anisotropy (FA-FWE) from diffusion imaging, were extracted. SVZ infiltration positively correlated with CBV, indicating higher perfusion in tumors. Significant CBV differences were noted between high and low SVZ infiltration cases at specific percentiles. Negative correlation was observed with TVM and positive correlation with FA-FWE, suggesting more infiltrative tumor growth. Significant differences in TVM and FA-FWE values were found between high and low SVZ infiltration cases. Glioblastomas with SVZ infiltration exhibit distinct imaging characteristics, including higher perfusion and lower cell density per voxel, indicating a more infiltrative growth and higher vascularization. Stem cell-like characteristics in SVZ-infiltrating cells could explain the increased infiltration and aggressive behavior. Understanding these imaging and biological correlations could enhance the understanding of glioblastoma evolution.

A method for evaluating deep generative models of images for hallucinations in high-order spatial context

Deep generative models (DGMs) have the potential to revolutionize diagnostic imaging. Generative adversarial networks (GANs) are one kind of DGM which are widely employed. The overarching problem with deploying any sort of DGM in mission-critical applications is a lack of adequate and/or automatic means of assessing the domain-specific quality of generated images. In this work, we demonstrate several objective and human-interpretable tests of images output by two popular DGMs. These tests serve two goals: (i) ruling out DGMs for downstream, domain-specific applications, and (ii) quantifying hallucinations in the expected spatial context in DGM-generated images. The designed datasets are made public and the proposed tests could also serve as benchmarks and aid the prototyping of emerging DGMs. Although these tests are demonstrated on GANs, they can be employed as a benchmark for evaluating any DGM. Specifically, we designed several stochastic context models (SCMs) of distinct image features that can be recovered after generation by a trained DGM. Together, these SCMs encode features as per-image constraints in prevalence, position, intensity, and/or texture. Several of these features are high-order, algorithmic pixel-arrangement rules which are not readily expressed in covariance matrices. We designed and validated statistical classifiers to detect specific effects of the known arrangement rules. We then tested the rates at which two different DGMs correctly reproduced the feature context under a variety of training scenarios, and degrees of feature-class similarity. We found that ensembles of generated images can appear largely accurate visually, and show high accuracy in ensemble measures, while not exhibiting the known spatial arrangements. The main conclusion is that SCMs can be engineered, and serve as benchmarks, to quantify numerous per image errors, i.e., hallucinations, that may not be captured in ensemble statistics but plausibly can affect subsequent use of the DGM-generated images.

Are Fibrous Cortical Defects (FCDs) and Non-Ossifying Fibromas (NOFs) Only Radiological Findings? The Relationship between Radiological/Clinical Findings and Physical Activity in Children and Adolescents: A Cross-Sectional Study.

Background: Fibrous cortical defect (FCD) and non-ossifying fibroma (NOF) are incidentally recognised and benign developmental lesions. The objective of this study was to ascertain the clinical manifestations and symptoms of FCDs/NOFs in children and adolescent patients, to characterise the lesions radiologically using X-ray and MRI techniques, and to determine the relationship between physical activity and the condition. Methods: The study included patients under the age of 18 with radiological lesions on their extremities. The lesions were classified as FCD or NOF in accordance with the distinctive imaging features. For each lesion, the bone involved, the site involved, the size of the lesion, and the type of lesion (according to the Ritschl classification) were recorded. In the anamnesis, the patient's presenting complaint, the character of the pain, if any, and the level of activity were investigated. Pain was quantified using the visual analogue scale (VAS) and the 21-Numbered Circle VAS (21-NCVAS). The 21-Numbered Circle Activity Scale (21-NCAS) and the International Physical Activity Questionnaire (IPAQ) were employed for the assessment of physical activity. Results: The study included 34 lesions in 28 children (14 girls/14 boys). There was no difference in age between girls and boys (p = 0.45). According to Ritschl's classification, 18 (52.9%) lesions were stage A, 9 (26.5%) were stage B, and 7 (20.6%) were stage C. The lesion size increased with increasing Ritschl stage (p < 0.02). The main presenting complaint was pain (n = 13, 49.9%). In 21.4% of the children (n = 6), lesions were detected incidentally on radiographs. According to IPAQ, 39.3% of the children were physically inactive. There was a significant negative correlation between 21-NCAS and Ritschl stage (r = -0.51, p < 0.05). Activity decreased as the Ritschl stage increased. There was a significant negative correlation between 21-NCAS and VAS (r = -0.69, p < 0.05). Conclusions: Spontaneous pain was observed in 49.9% of patients diagnosed with FCD/NOF. No correlation was identified between lesion size and the presence or severity of pain. As the severity of pain and Ritschl stage increased, there was a corresponding decrease in physical activity.

Rib Hemangiomas: Intriguing Findings from a Systematic Review of Rare Thoracic Tumors.

Background: Bone hemangiomas are rare benign vascular tumors, comprising less than 1% of all bone tumors. They are predominantly found in the vertebral body or skull; rib hemangiomas are particularly rare and are often misdiagnosed as malignant tumors. Given the high malignancy rate of primary rib tumors, understanding rib hemangiomas is crucial to avoid misdiagnosis. Methods: A systematic review was conducted according to PRISMA standards. A comprehensive literature search was performed in PubMed, EMBASE, Web of Science, and Scopus. Data on patient demographics, tumor characteristics, and clinical presentation were analyzed using STATA/SE 17. Results: From 306 articles, 40 studies including 43 patients met the inclusion criteria. Rib hemangiomas showed a bimodal age distribution, with peaks in patients younger than 30 years (mean age 21.43 ± 5.60 years) and ≥30 years (mean age 59.96 ± 9.70 years). Females were more affected (62.79%) than males (37.21%), with a ratio of 1.69:1. The tumors were most frequently located in mid-thoracic ribs (4-8) and predominantly on the left side of the thorax. The mean tumor size was 7.27 cm, with 76.19% exhibiting osteolytic changes. Clinically, 63.41% of cases were asymptomatic, while symptomatic cases mainly presented with pain. Conclusions: Rib hemangiomas, though rare, should be considered in the differential diagnosis of thoracic tumors. They present as well-demarcated lytic lesions with distinct imaging features, and they typically require complete surgical excision, which may be aided with preoperative embolization. Their accurate diagnosis involves a combination of radiologic and clinical evaluation. Further studies are needed to understand the disease's pathophysiology and to refine diagnostic and treatment protocols.

Magnetic resonance imaging characteristics of musculoskeletal hydatid disease

Background Hydatid disease is a parasitic infection seen in endemic areas. Musculoskeletal hydatid disease is rarely reported. Purpose To describe the magnetic resonance imaging (MRI) features of musculoskeletal hydatid disease and to highlight the specific findings in the diagnosis of hydatid cysts. Material and Methods The MRI scans of 29 cases diagnosed as musculoskeletal hydatid disease between 2000 and 2022 were retrospectively analyzed. The localization, size, appearance (unilocular or multilocular), signal characteristics, rim sign, presence of internal septa and membrane, and gadolinium enhancement pattern of hydatid cysts were evaluated. Results A total of 29 patients diagnosed with hydatid cyst were included in the study. Of the lesions, 18 were localized in bone and 11 were in soft tissue. The bone hydatid cysts on MRI showed heterogeneous low to intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images in the medullary bone. In 15/18 patients, there was also cortical destruction and extension into the adjacent soft tissue planes. In 8/11 cases where the cyst was located in muscle tissue, the “cyst or cysts within a cyst” appearance was observed on MRI. The rim sign was observed in 7/11 cases and the “water lily” sign was noted in 2/11 cases. Conclusion MRI provides valuable information for the diagnosis of hydatid disease with its distinctive imaging features. Knowledge of the different patterns of hydatid cysts on MRI may be helpful in the diagnosis of this disease.

CT and MR imaging characteristics of primary hepatic lymphoma

BackgroundPrimary hepatic lymphoma (PHL) is a rare primary liver tumor. The purpose of this study was to investigate the crucial imaging characteristics of PHL.MethodsCT/MR data and clinical features of 16 patients with pathologically proven PHL were retrospectively reviewed. The assessed imaging characteristics included lesion distribution, growth appearance, density or signal characteristics, and typical signs during the dynamic enhancement.ResultsA total of sixteen patients were included in this study, ranging in age from 27 to 86 years (nine men and seven women; mean age, 62 years). Right upper abdominal pain, malaise, or first detection during physical examination were the chief complaint. Dynamic contrast-enhanced CT and MRI demonstrated focal masses in thirteen patients (13/16, 81%), and multiple nodules in three patients (3/16, 19%). The lesions showed vascular floating sign in 10 patients (10/16, 63%) and biliary pass-through sign in 6 patients (6/16, 37%). Necrosis in PHLs were observed in 10 patients (10/16, 63%) and presented target sign on T2WI in 5 out of 11 patients (5/11, 45%) undergoing MRI. After enhancement, PHLs had multinodular sign in the arterial phase in 10 patients (10/16, 63%), and presented washout of contrast medium in the portal-venous or delayed phase in 12 patients (12/16, 75%), pseudocapsule in the delayed phase in 15 patients (15/16, 94%), and double-ring sign in the delayed phase in 8 patients (8/16, 50%).ConclusionPHL is generally seen in elderly patients with elevated beta-2-microglobulin levels. Its distinctive imaging features including obviously low ADC value, biliary/vascular floating sign, multinodular sign and double-ring sign in the delayed phase, may help to diagnose and differentiate PHL.

The influence of MOGAD on diagnosis of multiple sclerosis using MRI.

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an immune-mediated demyelinating disease that is challenging to differentiate from multiple sclerosis (MS), as the clinical phenotypes overlap, and people with MOGAD can fulfil the current MRI-based diagnostic criteria for MS. In addition, the MOG antibody assays that are an essential component of MOGAD diagnosis are not standardized. Accurate diagnosis of MOGAD is crucial because the treatments and long-term prognosis differ from those for MS. This Expert Recommendation summarizes the outcomes from a Magnetic Resonance Imaging in MS workshop held in Oxford, UK in May 2022, in which MS and MOGAD experts reflected on the pathology and clinical features of these disorders, the contributions of MRI to their diagnosis and the clinical use of the MOG antibody assay. We also critically reviewed the literature to assess the validity of distinctive imaging features in the current MS and MOGAD criteria. We conclude that dedicated orbital and spinal cord imaging (with axial slices) can inform MOGAD diagnosis and also illuminate differential diagnoses. We provide practical guidance to neurologists and neuroradiologists on how to navigate the current MOGAD and MS criteria. We suggest a strategy that includes useful imaging discriminators on standard clinical MRI and discuss imaging features detected by non-conventional MRI sequences that demonstrate promise in differentiating these two disorders.

Correlations of Imaging and Therapy in Breast Cancer Based on Molecular Patterns: An Important Issue in the Diagnosis of Breast Cancer.

Breast cancer is a global health issue affecting countries worldwide, imposing a significant economic burden due to expensive treatments and medical procedures, given the increasing incidence. In this review, our focus is on exploring the distinct imaging features of known molecular subtypes of breast cancer, underlining correlations observed in clinical practice and reported in recent studies. The imaging investigations used for assessment include screening modalities such as mammography and ultrasonography, as well as more complex investigations like MRI, which offers high sensitivity for loco-regional evaluation, and PET, which determines tumor metabolic activity using radioactive tracers. The purpose of this review is to provide a better understanding as well as a revision of the imaging differences exhibited by the molecular subtypes and histopathological types of breast cancer.

CT and MRI features of sarcomatoid urothelial carcinoma of the bladder and its differential diagnosis with conventional urothelial carcinoma

BackgroundSarcomatoid urothelial carcinoma (SUC) is a rare and highly malignant form of bladder cancer with a poor prognosis. Currently, there is limited information on the imaging features of bladder SUC and reliable indicators for distinguishing it from conventional urothelial carcinoma (CUC). The objective of our study was to identify the unique imaging characteristics of bladder SUC and determine factors that aid in its differential diagnosis.Materials and methodsThis retrospective study enrolled 22 participants with bladder SUC and 61 participants with CUC. The clinical, pathologic, and CT/MRI data from both groups were recorded, and a comparison was conducted using univariate analysis and multinomial logistic regression for distinguishing SUC from CUC.ResultsThe majority of SUCs were located in the trigone of the bladder and exhibited large tumor size, irregular shape, low ADC values, Vesical Imaging-Reporting and Data System (VI-RADS) score ≥ 4, the presence of necrosis, and an invasive nature. Univariate analysis revealed significant differences in terms of tumor location, shape, the maximum long-axis diameter (LAD), the short-axis diameter (SAD), ADC-value, VI-RADS scores, necrosis, extravesical extension (EVE), pelvic peritoneal spread (PPS), and hydronephrosis/ureteral effusion (p < .001 ~ p = .037) between SUCs and CUCs. Multinomial logistic regression found that only SAD (p = .014) and necrosis (p = .003) emerged as independent predictors for differentiating between SUC and CUC. The model based on these two factors achieved an area under curve (AUC) of 0.849 in ROC curve analysis.ConclusionBladder SUC demonstrates several distinct imaging features, including a high incidence of trigone involvement, large tumor size, and obvious invasiveness accompanied by necrosis. A bladder tumor with a large SAD and evidence of necrosis is more likely to be SUC rather than CUC.

Insights into Imaging of Pericardial and Cardiac Tuberculosis: A Comprehensive Review

AbstractPericardial and cardiac tuberculosis (TB) is an uncommon form of extrapulmonary TB that poses a considerable diagnostic challenge for clinicians due to its nonspecific and diverse presentation. Its presentation is so diverse and distinct that it necessitates advanced imaging with cardiac computed tomography (CT)/cardiac magnetic resonance (CMR) in addition to routine transthoracic echocardiography (TTE) for accurate diagnosis, myocardial involvement, management planning, and follow-up. This comprehensive review article highlights the highly valuable role of imaging modalities like echocardiography, cardiac CT, and CMR in the detailed evaluation of pericardial and cardiac TB, highlighting different forms of cardiac and pericardial involvement, their distinctive imaging features, and diagnostic challenges.

Automatic renal carcinoma biopsy guidance using forward-viewing endoscopic optical coherence tomography and deep learning

Percutaneous renal biopsy is commonly used for kidney cancer diagnosis. However, the biopsy procedure remains challenging in sampling accuracy. Here we introduce a forward-viewing optical coherence tomography probe for differentiating tumor and normal tissues, aiming at precise biopsy guidance. Totally, ten human kidney samples, nine of which had malignant renal carcinoma and one had benign oncocytoma, were used for system evaluation. Based on their distinct imaging features, carcinoma could be efficiently distinguished from normal renal tissues. Additionally, oncocytoma could be differentiated from carcinoma. We developed convolutional neural networks for tissue recognition. Compared to the conventional attenuation coefficient method, convolutional neural network models provided more accurate carcinoma predictions. These models reached a tissue recognition accuracy of 99.1% on a hold-out set of four kidney samples. Furthermore, they could efficiently distinguish oncocytoma from carcinoma. In conclusion, our convolutional neural network-aided endoscopic imaging platform could enhance carcinoma diagnosis during percutaneous renal biopsy procedures.

AB092. Imaging the histopathology subtypes of the growth hormone-secreting pituitary neuroendocrine tumor.

Sparsely granulated (SG) growth hormone-secreting pituitary neuroendocrine tumors (GH-PitNETs) often present with a more aggressive clinical course compared to densely granulated (DG) tumors. These subtypes exhibit distinct biological and imaging characteristics. Thus, this study aims to differentiate between the histopathological subtypes of GH-PitNETs using pre-operative magnetic resonance imaging (MRI). A retrospective analysis was conducted on 83 acromegalic patients treated at our institution between 2000 and 2010. Tumor volumes were segmented from preoperative MRIs, including T1-weighted, T2-weighted, T1 with contrast, and T2 fluid attenuated inversion recovery (FLAIR) sequences. Reference regions of interest (ROIs) were delineated using gray and white matter from the same sequences. Two pathologists reviewed pathology specimens for anti-cytokeratin (CAM 5.2) and Pit-1 expression. Clinical and radiological biomarkers were compared between SG and DG patients. A total of 83 patients with complete histopathology and 51 patients with complete MRIs were included in the analysis. SG PitNETs exhibited higher rates of supra-sellar invasion (61.5%, P<0.001), larger tumor sizes, lower pre-operative GH levels, and increased post-operative residual tumor (65.4%, P<0.001) compared to DG PitNETs. Additionally, SG PitNETs showed greater hyperintensity on T2-weighted images and enhanced contrast, whereas DG PitNETs exhibited less contrast enhancement. Utilization of these imaging biomarkers demonstrated an 94.1% accuracy in T2 FLAIR and overall of 78.7% predicting the histopathological subtypes of GH-PitNETs. Distinct histopathological subtypes of GH-PitNETs represent crucial prognostic factors. Utilizing multimodal pre-operative MRIs, clinicians can accurately identify sparsely granulated GH-PitNETs, facilitating improved treatment planning strategies.

Detection of systemic autoimmune diseases in an ongoing assessment program for hand arthralgias. A comparative analysis with inflammatory and non-inflammatory arthropathies.

Arthralgias are prevalent in systemic autoimmune rheumatic diseases (SARD), emphasizing the need for early recognition. This study aimed to estimate SARD frequency and compare clinical, laboratory, and imaging findings among SARD, non-inflammatory arthralgia (NIA), and RA in patients with hand arthralgias. A prospective evaluation program included individuals aged ≥18 with hand arthralgias. Baseline assessments covered clinical, laboratory, ultrasound, and radiography. Follow-up diagnoses categorized patients into SARD, NIA, and RA groups. Comparison between groups was performed using parametric and non-parametric tests. Two multivariate logistic regression analyzes were performed using the final diagnosis of SARD as the dependent variable (NIA and RA). ROC curves were calculated in those variables that presented an independent association in the multivariate analysis. Among 1053 patients, 9.6% were SARD (SLE 47%). Comparing SARD with NIA revealed higher CRP levels, power Doppler, less rhizarthrosis in ultrasound, and more ANA positivity in SARD patients. Distinct differences were observed between SARD and RA patients in terms of pain levels, swollen joints, metacarpophalangeal involvement and morning symptoms. Diagnostic markers demonstrated specific sensitivities and specificities: ANA for SARD versus NIA (82%, 34%), US not finding rhizarthrosis for SARD versus NIA (66%, 85%), CRP (cut-off >2.5 mg/L) sensitivity 52%, specificity 60%, AUC 0.62, RA antibodies (RF, 11 IU/mL) sensitivity 76%, specificity 74%, AUC 0.8, ACPA (1.25) sensitivity 50%, specificity 98%, AUC 0.7, ANA+ sensitivity 95%, specificity 32%, AUC 0.7, and US absence of synovitis sensitivity 82%, specificity 34%, AUC 0.75. This study highlights distinct clinical, laboratory, and imaging features differentiating SARD-related hand arthralgia from non-SARD hand arthralgia and RA.

Malignant Rhabdoid Tumor and Related Pediatric Tumors: Multimodality Imaging Review with Pathologic Correlation.

Malignant rhabdoid tumors (MRTs) are rare but lethal solid neoplasms that overwhelmingly affect infants and young children. While the central nervous system is the most common site of occurrence, tumors can develop at other sites, including the kidneys and soft tissues throughout the body. The anatomic site of involvement dictates tumor nomenclature and nosology. While the clinical and imaging manifestations of MRTs and other more common entities may overlap, there are some site-specific distinctive imaging characteristics. Irrespective of the site of occurrence, somatic and germline mutations in SMARCB1, and rarely in SMARCA4, underlie the entire spectrum of rhabdoid tumors. MRTs have a simple and remarkably stable genome but can demonstrate considerable molecular and biologic heterogeneity. Related neoplasms encompass an expanding category of phenotypically dissimilar (nonrhabdoid tumors driven by SMARC-related alterations) entities. US, CT, MRI, and fluorodeoxyglucose PET/CT or PET/MRI facilitate diagnosis, initial staging, and follow-up, thus informing therapeutic decision making. Multifocal synchronous or metachronous rhabdoid tumors occur predominantly in the context of underlying rhabdoid tumor predisposition syndromes (RTPSs). These autosomal dominant disorders are driven in most cases by pathogenic variants in SMARCB1 (RTPS type 1) and rarely by pathogenic variants in SMARCA4 (RTPS type 2). Genetic testing and counseling are imperative in RTPS. Guidelines for imaging surveillance in cases of RTPS are based on age at diagnosis. ©RSNA, 2024 Supplemental material is available for this article.

Large-scale calcium imaging reveals a systematic V4 map for encoding natural scenes

Biological visual systems have evolved to process natural scenes. A full understanding of visual cortical functions requires a comprehensive characterization of how neuronal populations in each visual area encode natural scenes. Here, we utilized widefield calcium imaging to record V4 cortical response to tens of thousands of natural images in male macaques. Using this large dataset, we developed a deep-learning digital twin of V4 that allowed us to map the natural image preferences of the neural population at 100-µm scale. This detailed map revealed a diverse set of functional domains in V4, each encoding distinct natural image features. We validated these model predictions using additional widefield imaging and single-cell resolution two-photon imaging. Feature attribution analysis revealed that these domains lie along a continuum from preferring spatially localized shape features to preferring spatially dispersed surface features. These results provide insights into the organizing principles that govern natural scene encoding in V4.

Multiple brain abscesses caused by Nocardia farcinica infection after hand injury: A case report and literature review.

Nocardia infection is commonly regarded as an opportunistic pulmonary pathogen affecting debilitated or immunocompromised individuals. Brain abscesses caused by Nocardia farcinica are rare and pose a diagnostic challenge. Traditional diagnostic techniques for identifying Nocardia species, such as blood culture, microscopy, and pathology, have shown inadequate performance. In the reported case, we applied metagenomic next-generation sequencing (mNGS) to diagnose a case of brain abscess due to N. farcinica. A 66-year-old female developed a brain abscess after sustaining a hand injury. The patient exhibited a gradual change in personality and experienced tremors in her right upper limb for a duration of 1 month. The pathogen responsible for the multiple brain abscesses was identified in the cerebrospinal fluid as N. farcinica through mNGS. Antibiotic treatment included trimethoprim-sulfamethoxazole, linezolid, amikacin, meropenem, and moxifloxacin. The patient's symptoms and signs improved significantly after administration of antibiotics to which the pathogen is known to be sensitive. After 5 months of follow-up, magnetic resonance imaging of the head showed that the abscess was basically cured. The patient lived a normal life with no adverse drug reactions. Nocardia brain infection is characterized by an insidious onset and lacks distinctive clinical and imaging features. mNGS was advantageous for the timely identification and management of Nocardia-associated brain abscess in the present case and obviated the need for invasive brain surgery. Expeditious and precise diagnosis coupled with prompt antibiotic therapy can significantly reduce the mortality rate associated with this condition.

The Silent Masquerade: Clinical and Imaging Features of Asymptomatic Vitreoretinal Lymphoma

PurposeTo report and characterize ocular features of asymptomatic vitreoretinal lymphoma (VRL) associated with primary central nervous system lymphoma (PCNSL), by examining clinical and multimodal imaging characteristics and comparing with symptomatic VRL. DesignRetrospective cross-sectional study. MethodsPatients with cytologically or molecularly confirmed VRL were included. Patients were classified into three groups: primary VRL (PVRL), symptomatic VRL associated with PCNSL (PCNSL-S), or asymptomatic VRL associated with PCNSL (PCNSL-AS). Data encompassing demographics, visual symptoms, visual acuity (VA), and imaging characteristics were collected. Cross-sectional analyses of quantitative and categorical variables among groups were performed with one-way ANOVA and multinomial linear regression analyses. ResultsThe study included 104 eyes from 56 patients with VRL. Twenty-nine patients (52%) were diagnosed with PVRL, and 27 patients (48%) were diagnosed with VRL associated with PCNSL. Among these, 17 (63%) reported visual symptoms (PCNSL-S), whereas 10 (37%) were asymptomatic (PCNSL-AS). PCNSL-AS patients exhibited better VA than PVRL patients (0.11 vs. 0.76 LogMAR, p=0.04) and distinct clinical features, with lower rates of anterior segment involvement (odds ratio [OR]=0.02; 95% confidence interval [CI] 0.12-0.84; p<0.01) and vitritis (OR= 0.32; 95%CI 0.11-0.91; p=0.03). Subretinal infiltration was less common in PCNSL-AS cases compared to PVRL (OR= 0.14; 95%CI 0.02-1.11; p=0.06) and PCNSL-S (OR: 0.08; 95%CI 0.01-0.69 p=0.05) and was associated with worse VA (estimate=0.55 LogMAR; 95%CI 0.29-0.8; p<0.01). ConclusionThis study describes distinctive clinical and imaging features of asymptomatic VRL associated with PCNSL, characterized by better VA and less severe ocular involvement. The findings highlight the pivotal role of multimodal imaging in facilitating early detection of VRL in the staging of PCNSL. Future guidelines for PCNSL management should consider the necessity of diagnosing patients with asymptomatic VRL.