White cord syndrome (WCS), also referred to as reperfusion injury of the spinal cord, is a rare condition involving sudden neurological deterioration following cervical spinal decompression. The syndrome is diagnosed in the absence of an iatrogenic cord injury or perioperative complications. Both loss of neurophysiological signaling during intraoperative monitoring and the appearance of hyper-intensity on T2-weighted magnetic resonance imaging are hallmarks of WCS. We present a report of a female patient who presented with the condition and followed her imaging studies longitudinally. Imaging studies showed prolonged and persistent contrast enhancement over a year and a half postsurgery. Such findings have not previously been reported with WCS. We provide a brief review of the literature, highlighting the main radiologic findings.

Synovitis has emerged as a tissue target of importance in OA research and is commonly evaluated with medical imaging.

The purpose of this scoping review was to identify and describe the medical imaging techniques and definitions used by knee OA researchers to assess synovitis, summarize their advantages and disadvantages, and identify opportunities for future work.

We included full-text peer-reviewed English publications including adults diagnosed with knee OA. Studies were included if one or more medical imaging modalities were used to assess synovitis in the knee.Studies of inflammatory arthritis, joint replacement, and synovial joints other than the knee were excluded. Animal studies and literature syntheses were also excluded.

MEDLINE, SCOPUS, and Google scholar databases were systematically searched for publications (2000-2023) using the following medical subject headings (MeSH): "osteoarthritis, knee", "magnetic resonance imaging", "ultrasonography", "synovitis".

1154 articles were identified from searching medical databases. After removal of duplicates, abstract screening, and full text reading, 251 articles were included in the final review. MRI is the most common modality employed to assess knee synovitis, followed by US imaging. Varied imaging techniques used in the assessment of joint synovitis may be targeting divergent constructs of synovial remodeling and inflammation, which complicates interpretation of results.

There is no consensus on the best method for imaging of knee synovitis in OA. Future work may benefit from the evaluation of synovitis separate from joint effusion, and their associations with histologic findings to discriminate between features of synovial inflammation and remodeling.

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is an uncommon diagnosis in the differential for leptomeningeal enhancement. This case highlights the presentation, imaging features, and investigations important for diagnosis of GFAP astrocytopathy to ensure timely treatment of this corticosteroid-responsive disease. A 50-year-old man from Hong Kong presented with 10 days of progressive urinary retention, dysarthria, diplopia, and gait ataxia after a viral illness. Initial nonenhanced MRI brain was negative. After he developed encephalopathy, repeat MRI with gadolinium on admission day 6 revealed diffuse basal and spinal cord leptomeningeal enhancement. This imaging pattern, in combination with CSF eosinophilia and epidemiologic risk factors, precipitated empiric treatment for tuberculosis meningitis (including dexamethasone). Extensive investigations for an alternate infectious, autoimmune, or malignant diagnosis were negative. Dexamethasone cessation after a gastrointestinal bleed led to clinical and radiologic deterioration. This prompted further CSF and serum testing, which showed positive CSF GFAP-IgG immunofluorescence assay (IFA) (1:128) solidifying the diagnosis of autoimmune GFAP astrocytopathy. Induction with high-dose corticosteroids, intravenous immunoglobulins, and rituximab produced clinical and radiologic remission. Autoimmune GFAP astrocytopathy is an autoimmune disorder with a characteristic perivascular radial enhancement imaging pattern. However, a variety of other clinical and radiologic presentations may be seen, including leptomeningeal enhancement and T2/FLAIR hyperintensities. Diagnosis is confirmed with CSF GFAP-IgG testing. We provide a differential diagnosis for leptomeningeal enhancement and highlight clinical pearls for the diagnosis and management of autoimmune GFAP astrocytopathy.

Intravenously (IV) administered Gadolinium-based-contrast-agents (GBCAs) can enter the intracranial cerebrospinal-fluid (CSF) space via weak barriers between blood and CSF at multiple locations in the brain. This enables IV-GBCAs to be used as a tracer to study CSF circulation and clearance in the brain. With proper optimization, IV-GBCA induced signal changes can be robustly detected in various brain regions associated with CSF circulation. Nevertheless, whether these signal changes can be attributed to GBCA concentration changes in the CSF space should be interpreted with caution. This review attempts to discuss several technical challenges for using IV-GBCA MRI to study CSF circulation in the brain. First, it is critical to minimize the partial volume effects from the blood compartment as IV-GBCAs can present in both the blood and CSF compartments for a long time. Second, MRI approaches that can provide a quantitative measure of GBCA concentration in the CSF are preferred as raw MR signal intensities can often have a complicated relationship with GBCA concentration. Third, regions with intracranial and extracranial blood supply should be analyzed separately because GBCA distribution in regions with extracranial blood supply may not be a proper indicator for CSF clearance from the brain. Fourth, differences in the cerebrovasculature should be considered when comparing IV-GBCA concentration changes in the CSF in brain diseases. Finally, a proper reference signal needs to be established to calibrate longitudinal post-GBCA signals across sessions. Some of these issues may also apply to intrathecal GBCA MRI studies.

Diagnosis of brain tumors increased in sub-Saharan Africa since the advent of computed tomography (CT)-scans and magnetic resonance imaging (MRI) in these regions, enabling easy diagnosis. However, some histological types of brain tumors can be confusing, especially on CT-scan, simulating other pathologies such as inflammatory granulomas or pyogenic abscesses. MRI, in this instance, with its diffusion-weighted imaging, susceptibility weighted imaging, or perfusion imaging, is important to help with accurate diagnosis. The down side of these imaging facilities, however, is that less and less importance is accorded to proper and detailed history taking. Such a care-free attitude to history taking can be costly, especially in resource strained environments.

We report the case of a 06-year-old child who presented with seizures associated with headaches and vomiting. In this case, proper history taking following the surgical intervention revealed a history of head trauma after a fall with a scalp wound, which was suppurated but later progressed well. The CT scan showed a solid cystic lesion. The first component is a ring enhanced portion (hyperdense ring with the hypodense center, surrounded by edema) with central calcification located in the frontal region, and the second component is a cystic portion located in the temporal region. This lesion with dual component was more suggestive of a tumoral lesion on imaging than an abscess. The child did not benefit from further imaging due to unavailability in the region as well as the socioeconomic status of the family making them incapable of going elsewhere to do it. A decision to surgically excise the lesion was made, and during surgery, we found a well-circumscribed yellowish lesion associated with an arachnoid cyst. The capsule of the lesion was very thick, and after opening it, the content was pus combined with debris. The child did well on antibiotic therapy post-surgery. The follow-up was unremarkable.

Brain MRI is essential to differentiate some pyogenic brain abscesses from tumors. However, meticulous history taking is important to gather as much information as possible about any medical pathology, which would then be corroborated with the physical examination findings and imaging to increase diagnostic accuracy and minimize misdiagnosis.

In infectious meningitis, pathogens preferentially attack the leptomeninges (pia mater and arachnoid) rather than the pachymeninges (dura mater). This study aims to provide ultra-anatomical insights from our extensive collection of electron microscopy images and propose mechanisms, highlighting structures that favor the introduction, adherence, colonization, and proliferation of microorganisms leading to spinal meningitis. Over several years, we analyzed an extensive collection of transmission and scanning electron microscopy images of human spinal meninges captured in our laboratories. Upon examining 378 of those images, we identified potential sites for the iatrogenic or hematogenic introduction and adherence of microorganisms, as well as sites for their colonization and proliferation. These included the outer surface of the spinal dural sac, structures within the epidural space, and the spinal dural sac itself, which comprises compact dura mater with interwoven collagen fibers and tightly bound arachnoid cells. Also, the subdural (extra-arachnoid) compartment, consisting of fragile neurothelial cells prone to rupture under force, formed an acquired spinal subdural space, a new subarachnoid compartment, limited by arachnoid trabeculae, that surrounded the nerve roots and spinal cord and the pia mater. Macrophages, fibroblasts, mast cells, and plasma cells were also observed within the dura mater, arachnoid layer, arachnoid trabeculae, and pia mater. These images illustrate how the characteristics of the meningeal layers could contribute to bacterial adhesion and proliferation at various locations, inducing selective inflammation during (iatrogenic) spinal meningitis. In addition, the images help to explain why magnetic resonance imaging enhancement appears preferentially at specific sites.

Brain tumors are a disease that kills thousands of people worldwide each year. Early identification through diagnosis is essential for monitoring and treating patients. The proposed study brings a new method through intelligent computational cells that are capable of segmenting the tumor region with high precision. The method uses deep learning to detect brain tumors with the "You only look once" (Yolov8) framework, and a fine-tuning process at the end of the network layer using intelligent computational cells capable of traversing the detected region, segmenting the edges of the brain tumor. In addition, the method uses a classification pipeline that combines a set of classifiers and extractors combined with grid search, to find the best combination and the best parameters for the dataset. The method obtained satisfactory results above 98% accuracy for region detection, and above 99% for brain tumor segmentation and accuracies above 98% for binary classification of brain tumor, and segmentation time obtaining less than 1 s, surpassing the state of the art compared to the same database, demonstrating the effectiveness of the proposed method. The new approach proposes the classification of different databases through data fusion to classify the presence of tumor in MRI images, as well as the patient's life span. The segmentation and classification steps are validated by comparing them with the literature, with comparisons between works that used the same dataset. The method addresses a new generative AI for brain tumor capable of generating a pre-diagnosis through input data through Large Language Model (LLM), and can be used in systems to aid medical imaging diagnosis. As a contribution, this study employs new detection models combined with innovative methods based on digital image processing to improve segmentation metrics, as well as the use of Data Fusion, combining two tumor datasets to enhance classification performance. The study also utilizes LLM models to refine the pre-diagnosis obtained post-classification. Thus, this study proposes a Computer-Aided Diagnosis (CAD) method through AI with PDI, CNN, and LLM.

Brain tumors pose significant diagnostic and therapeutic challenges due to their diverse treatment responses and complex imaging characteristics. Traditional MRI techniques often struggle to differentiate between tumor recurrence and post-treatment changes such as pseudoprogression and necrosis, highlighting the need for more accurate diagnostic tools.

This retrospective study conducted at a single tertiary care center and evaluated the diagnostic efficacy of Treatment Response Assessment Maps (TRAMs), also known as Contrast Clearance Analysis (CCA), in distinguishing between tumor recurrence and post-treatment changes in patients who underwent initial treatment for brain tumors. Data from 27 patients were analyzed, including 10 who underwent surgical resection (Group 1) and 17 who had serial images and TRAMs/CCA assessment (Group 2).

In Group 1, TRAMs/CCA demonstrated nine positive results, with 8 cases of tumor recurrence confirmed via biopsy. A biopsy also confirmed one negative result after a discussion with the patient. In Group 2, where patients did not undergo biopsy, TRAMs/CCA results varied but correlated with clinical outcomes, underscoring the potential utility of TRAMs/CCA in guiding treatment decisions. These findings suggest that TRAMs/CCA may have superior diagnostic performance compared to traditional MRI in differentiating between tumors.

TRAMs/CCA represents a promising advancement in the imaging assessment of brain tumor treatment response, offering higher sensitivity than conventional MRI methods. While implementing TRAMs/CCA could potentially improve diagnostic accuracy and optimize therapeutic strategies for patients with brain tumors, the final decision remains highly dependent on patient-centered discussions.

The diagnosis of leptomeningeal metastatic disease has major prognostic and therapeutic implications. We report 13 patients with a radiologically distinct kind of focal, enhancing leptomeningeal lesion on brain MRI that mimics leptomeningeal metastatic disease.

These patients were assessed at University Health Network (Toronto, Canada) between January 2001 and December 2023.

Median age was 68 years (range, 55-78 years) and 10 patients were women. All patients had brain magnetic resonance imaging (MRI) including contrast-enhanced T2-weighted fluid attenuation inversion recovery (FLAIR) and T1-weighted spin echo sequences. MRI in all 13 patients showed a focal enhancing lesion located along the leptomeningeal surface of the brain. The MRI exams were reported as possible or likely leptomeningeal metastatic disease for the majority (9/13) of patients. Each lesion was curvilinear rather than sheet-like, and some lesions consisted of multiple connected/branching curvilinear structures with the appearance of abnormal vessels. The lesions were distinct from normal blood vessels. Some lesions had a visible connection with a nearby cortical vein. Follow-up contrast-enhanced brain MRI for 8/13 (62%) patients at a median of 3.9 years (IQR 2.4-6.6 years) showed all lesions were unchanged over time. Another 2/13 (15%) patients had clinical and CT brain follow-up after one year with no evidence of metastatic disease.

We describe a distinct kind of focal, enhancing leptomeningeal lesion on brain MRI that mimics metastatic disease. These lesions are likely a type of low-flow vascular anomaly. Their curvilinear/branching shape and intense enhancement particularly on T2-weighted FLAIR images distinguish these lesions from tumors.

Evaluating masses of mesenchymal and epithelial origin accurately using computed tomography (CT) has several limitations in dogs. This study aimed to present dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters to aid in improving the diagnostic accuracy for masses of mesenchymal and epithelial origin in veterinary medicine. Four dogs diagnosed with benign and malignant soft tissue sarcoma (STS), cholesteatoma, or squamous cell carcinoma underwent CT, conventional MRI, and DCE-MRI. Ktrans is a quantitative DCE-MRI parameter representing vascular permeability and tissue perfusion and is related to the potential for malignancy. Hemangiopericytomas (Grade II, STS) showed a higher Ktrans than normal muscle tissue and myxosarcoma (Grade I, STS). Squamous cell carcinoma (a malignant epithelial tumor) also showed a higher Ktrans than normal muscle tissue and cholesteatoma (a mass originating from keratinized squamous epithelium). These results suggest that higher Ktrans values may indicate a greater likelihood that a lesion is more malignant. In conclusion, Ktrans might be useful as a biomarker for evaluating the malignancy of a mass and as an indicator of lesion characteristics in dogs.

Central nervous system (CNS) involvement is seen across a variety of rheumatic diseases. Common CNS manifestations include cerebrovascular events (such as ischemic and hemorrhagic strokes, cerebral venous sinus thrombosis), seizures, headaches, demyelinating lesions (such as optic neuritis, myelitis, parenchymal lesions), meningeal disease (leptomeningeal and pachymeningeal involvement, meningitis), and others. While most patients have other systemic symptoms of their rheumatic disease at the time of developing neurologic complications, some may present with CNS disease as the first symptom of their rheumatic disease. This review discusses rheumatic diseases with CNS manifestations and provides neuroimaging findings observed among affected individuals.

To describe the radiological features of patients with headache as a presenting symptom of neurosarcoidosis.

Neurologic complications occur in approximately 5%-10% of patients with sarcoidosis, and approximately 50% of these patients have neurologic deficits at the time sarcoidosis is first diagnosed. A wide spectrum of central and peripheral nervous system clinical manifestations may be observed, including cranial nerve palsies, sensory and/or motor deficits, and headache. Magnetic resonance imaging (MRI) results in patients with neurosarcoidosis may include abnormal contrast enhancement, structural masses, and demyelinating lesions.

This single-center retrospective cohort study assessed patients who were diagnosed with neurosarcoidosis in an urban tertiary care center between 1995 and 2016. We included patients who had MRI results at the time of diagnosis. Patients were divided into two groups based on the presence or absence of headache as a presenting symptom. The MRI result of meningeal contrast enhancement was reviewed.

Of the 110 patients analyzed, 30 (27.3%) had an initial presenting symptom of headache while 80 (72.7%) did not. Patients with headache had a higher proportion of meningeal contrast enhancement on MRI (66.7% [20/30] vs. 25.0% [20/80]; p < 0.001) and leptomeningeal involvement (53.3% [16/30] vs. 7.5% [6/80], p < 0.001) compared to patients with no headache. However, those with headache had a lower proportion of spinal cord localization (13.8% [4/29] vs. 34.2% [26/76], p = 0.038) and intraparenchymal central nervous system involvement (16.7% [5/30] vs. 51.3% [41/80], p = 0.001) compared to patients with no headache.

Patients with neurosarcoidosis who presented with headache as an initial symptom had a higher proportion of meningeal contrast enhancement seen by MRI than patients who presented with other neurological symptoms. This suggests a clinico-radiologic link between headache and meningeal disruption in patients with neurosarcoidosis.

This study aimed to elucidate the association between IV contrast media CT and acute kidney injury (AKI) and in-hospital mortality among patients requiring emergency admission.

In this retrospective observational study, we examined AKI within 48 hours after CT, renal replacement therapy (RRT) dependence at discharge, and in-hospital mortality in patients undergoing contrast-enhanced CT or nonenhanced CT. We performed 1:1 propensity score matching to adjust for confounders in the association between IV contrast media use and outcomes. Subgroup analyses were performed according to age, sex, diagnosis at admission, ICU admission, and preexisting chronic kidney disease (CKD).

This study used the Medical Data Vision database between 2008 and 2019. This database is Japan's largest commercially available hospital-based claims database, covering about 45% of acute-care hospitals in Japan, and it also records laboratory results.

None.

The study included 144,149 patients with (49,057) and without (95,092) contrast media exposure, from which 43,367 propensity score-matched pairs were generated. Between the propensity score-matched groups of overall patients, exposure to contrast media showed no significant risk of AKI (4.6% vs. 5.1%; odds ratio [OR], 0.899; 95% CI, 0.845-0.958) or significant risk of RRT dependence (0.6% vs. 0.4%; OR, 1.297; 95% CI, 1.070-1.574) and significant benefit for in-hospital mortality (5.4% vs. 6.5%; OR, 0.821; 95% CI, 0.775-0.869). In subgroup analyses regarding preexisting CKD, exposure to contrast media was a significant risk for AKI in patients with CKD but not in those without CKD.

In this large-scale observational study, IV contrast media was not associated with an increased risk of AKI but concurrently showed beneficial effects on in-hospital mortality among patients requiring emergency admission.

Radiology has seen tremendous evolution in the last few decades. At the same time, oncology has made great strides in diagnosing and treating cancer. Distant metastases of neoplasms are being encountered more often in light of longer patient survival due to better therapeutic strategies and diagnostic methods. Brain metastasis (BM) is a dismal manifestation of systemic cancer. In the present scenario, magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography (PET) are playing a big role in providing molecular information about cancer. Lately, molecular imaging has emerged as a stirring arena of dynamic imaging techniques that have enabled clinicians and scientists to noninvasively visualize and understand biological processes at the cellular and molecular levels. This knowledge has impacted etiopathogenesis, detection, personalized treatment, drug development, and our understanding of carcinogenesis. This article offers insight into the molecular biology underlying brain metastasis, its pathogenesis, imaging protocols, and algorithms. It also discusses disease-specific molecular imaging features, focusing on common tumors that spread to the brain, such as lung, breast, colorectal cancer, melanoma, and renal cell carcinoma. Additionally, it covers various targeted treatment options, criteria for assessing treatment response, and the role of artificial intelligence in diagnosing, managing, and predicting prognosis for patients with brain metastases.

We aimed to test whether synthetic T1-weighted imaging derived from a post-contrast Quantitative Transient-state Imaging (QTI) acquisition enabled revealing pathological contrast enhancement in intracranial lesions.

The analysis included 141 patients who underwent a 3 Tesla-MRI brain exam with intravenous contrast media administration, with the post-contrast acquisition protocol comprising a three-dimensional fast spoiled gradient echo (FSPGR) sequence and a QTI acquisition. Synthetic T1-weighted images were generated from QTI-derived quantitative maps of relaxation times and proton density. Two neuroradiologists assessed synthetic and conventional post-contrast T1-weighted images for the presence and pattern of pathological contrast enhancement in intracranial lesions. Enhancement volumes were quantitatively compared.

Using conventional imaging as a reference, synthetic T1-weighted imaging was 93% sensitive in revealing the presence of contrast enhancing lesions. The agreement for the presence/absence of contrast enhancement was almost perfect both between readers (k = 1 for both conventional and synthetic imaging) and between sequences (k = 0.98 for both readers). In 91% of lesions, synthetic T1-weighted imaging showed the same pattern of contrast enhancement visible in conventional imaging. Differences in enhancement pattern in the remaining lesions can be due to the lower spatial resolution and the longer acquisition delay from contrast media administration of QTI compared to FSPGR. Overall, enhancement volumes appeared larger in synthetic imaging.

QTI-derived post-contrast synthetic T1-weighted imaging captures pathological contrast enhancement in most intracranial enhancing lesions. Further comparative studies employing quantitative imaging with higher spatial resolution is needed to support our data and explore possible future applications in clinical trials.

Prediction of glioma is crucial to provide a precise treatment plan to optimize the prognosis of children with glioma. However, studies on the grading of pediatric gliomas using radiomics are limited. Meanwhile, existing methods are mainly based on only radiomics features, ignoring intuitive information about tumor morphology on traditional imaging features. This study aims to utilize multiparametric magnetic resonance imaging (MRI) to identify high-grade and low-grade gliomas in children and establish a classification model based on radiomics features and clinical features. A total of 85 children with gliomas underwent tumor resection, and part of the tumor tissue was examined pathologically. Patients were categorized into high-grade and low-grade groups according to World Health Organization guidelines. Preoperative multiparametric MRI data, including contrast-enhanced T1-weighted imaging, T2-weighted imaging, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted images, and apparent diffusion coefficient sequences, were obtained and labeled by two radiologists. The images were preprocessed, and radiomics features were extracted for each MRI sequence. Feature selection methods were used to select radiomics features, and statistically significant clinical features were identified using t-tests. The selected radiomics features and conventional MRI features were used to train the AutoGluon models. The improved model, based on radiomics features and conventional MRI features, achieved a balanced classification accuracy of 66.59%. The cross-validated areas under the receiver operating characteristic curve for the classifier of AutoGluon frame were 0.8071 on the test dataset. The results indicate that the performance of AutoGluon models can be improved by incorporating conventional MRI features, highlighting the importance of the experience of radiologists in accurately grading pediatric gliomas. This method can help predict the grade of pediatric glioma before pathological examination and assist in determining the appropriate treatment plan, including radiotherapy, chemotherapy, drugs, and gene surgery.

Meningitis is the infection of the meninges, which are connective tissue membranes covering the brain, and it most commonly affects the leptomeninges. Clinically, meningitis may present with fever, neck stiffness, altered mental status, headache, vomiting, and neurological deficits. Encephalitis is an infection of the brain, which usually presents with fever, altered mental status, neurological deficits, and seizure. Meningitis and encephalitis are serious conditions which could also coexist, with high morbidity and mortality, thus requiring prompt diagnosis and treatment. Imaging plays an important role in the clinical management of these conditions, especially Magnetic Resonance Imaging. It is indicated to exclude mimics and evaluate the presence of complications. The aim of this review is to depict imaging findings of the most common meningitis and encephalitis.

Spontaneous intracranial hypotension (SIH) typically presents as an acute orthostatic headache during an upright position, secondary to spinal cerebrospinal fluid leaks. New evidence indicates that a lumbar puncture may not be essential for diagnosing every patient with SIH. Spinal neuroimaging protocols used for diagnosing and localizing spinal cerebrospinal fluid leaks include brain/spinal MRI, computed tomography myelography, digital subtraction myelography, and radionuclide cisternography. Complications of SIH include subdural hematoma, cerebral venous thrombosis, and superficial siderosis. Treatment options encompass conservative management, epidural blood patches, and surgical interventions. The early application of epidural blood patches in all patients with SIH is suggested.

Central nervous system (CNS) tuberculosis is a post-primary form of tuberculosis. It has high mortality and morbidity rates despite early diagnosis and treatment. CNS tuberculosis can manifest as subacute/chronic meningitis, parenchymal tuberculous lesions, and spinal tuberculosis. Hematogenous spread of tuberculous bacilli to the brain results in the development of so called "rich foci" on the pial surface, ependyma, and grey-white matter junction. Rupture of these "rich foci" into the subarachnoid space triggers an intense granulomatous inflammatory reaction. Tuberculous meningitis can manifest as leptomeningitis or pachymeningitis. Intracranial parenchymal tuberculous lesions may present as tuberculoma, tuberculous abscess, cerebritis, rhombencephalitis, and encephalopathy, with atypical presentations not uncommon. Complications of CNS tuberculosis encompass hydrocephalus, syrinx formation, vasculitis, infarcts, neuritis, and enduring neurological deficits. Post-contrast 3D fluid-attenuated inversion recovery (FLAIR) and post-contrast T1 spin-echo sequences excel in detecting tuberculous meningitis compared to other conventional magnetic resonance imaging (MRI) sequences. In proton magnetic resonance spectroscopy (PMRS), the presence of a lipid peak at 1.3 ppm is indicative of tuberculous lesions. Magnetization transfer (MT) imaging enhances the detection of tuberculous lesions, as the magnetization transfer ratio (MTR) of tuberculous pathologies, owing to their high lipid content, is lower than that in bacterial or fungal pathologies and higher than that in viral pathologies. This review article delves into the various typical and atypical imaging presentations of CNS tuberculosis in MRI, along with recent advances in imaging techniques.

The glymphatic system, a macroscopic waste clearance system in the brain, is crucial for maintaining neural health. It facilitates the exchange of cerebrospinal and interstitial fluid, aiding the clearance of soluble proteins and metabolites and distributing essential nutrients and signaling molecules. Emerging evidence suggests a link between glymphatic dysfunction and the pathogenesis of neurodegenerative disorders, including Alzheimer's, Parkinson's, and Huntington's disease. These disorders are characterized by the accumulation and propagation of misfolded or mutant proteins, a process in which the glymphatic system is likely involved. Impaired glymphatic clearance could lead to the buildup of these toxic proteins, contributing to neurodegeneration. Understanding the glymphatic system's role in these disorders could provide insights into their pathophysiology and pave the way for new therapeutic strategies. Pharmacological enhancement of glymphatic clearance could reduce the burden of toxic proteins and slow disease progression. Neuroimaging techniques, particularly MRI-based methods, have emerged as promising tools for studying the glymphatic system in vivo. These techniques allow for the visualization of glymphatic flow, providing insights into its function under healthy and pathological conditions. This narrative review highlights current MRI-based methodologies, such as motion-sensitizing pulsed field gradient (PFG) based methods, as well as dynamic gadolinium-based and glucose-enhanced methodologies currently used in the study of neurodegenerative disorders.

Objective.Alternating electric fields (AEF) therapy is a treatment modality for patients with glioblastoma. Tumor characteristics such as size, location, and extent of peritumoral edema may affect the AEF strength and distribution. We evaluated the sensitivity of the AEFs in a realistic 3D rat glioma model with respect to these properties.Approach.The electric properties of the peritumoral edema were varied based on calculated and literature-reported values. Models with different tumor composition, size, and location were created. The resulting AEFs were evaluated in 3D rat glioma models.Main results.In all cases, a pair of 5 mm diameter electrodes induced an average field strength >1 V cm-1. The simulation results showed that a negative relationship between edema conductivity and field strength was found. As the tumor core size was increased, the average field strength increased while the fraction of the shell achieving >1.5 V cm-1decreased. Increasing peritumoral edema thickness decreased the shell's mean field strength. Compared to rostrally/caudally, shifting the tumor location laterally/medially and ventrally (with respect to the electrodes) caused higher deviation in field strength.Significance.This study identifies tumor properties that are key drivers influencing AEF strength and distribution. The findings might be potential preclinical implications.

Little is known about the etiology, clinical presentation, management, and outcome of central nervous system (CNS) infections in Indonesia, a country with a high burden of infectious diseases and a rising prevalence of HIV.

We included adult patients with suspected CNS infections at two referral hospitals in a prospective cohort between April 2019 and December 2021. Clinical, laboratory, and radiological assessments were standardized. We recorded initial and final diagnoses, treatments, and outcomes during 6 months of follow-up.

Of 1051 patients screened, 793 were diagnosed with a CNS infection. Patients (median age 33 years, 62% male, 38% HIV-infected) presented a median of 14 days (IQR 7-30) after symptom onset, often with altered consciousness (63%), motor deficits (73%), and seizures (21%). Among HIV-uninfected patients, CNS tuberculosis (TB) was most common (60%), while viral (8%) and bacterial (4%) disease were uncommon. Among HIV-infected patients, cerebral toxoplasmosis (41%) was most common, followed by CNS TB (19%), neurosyphilis (15%), and cryptococcal meningitis (10%). A microbiologically confirmed diagnosis was achieved in 25% of cases, and initial diagnoses were revised in 46% of cases. In-hospital mortality was 30%, and at six months, 45% of patients had died, and 12% suffered from severe disability. Six-month mortality was associated with older age, HIV, and severe clinical, radiological and CSF markers at presentation.

CNS infections in Indonesia are characterized by late presentation, severe disease, frequent HIV coinfection, low microbiological confirmation and high mortality. These findings highlight the need for earlier disease recognition, faster and more accurate diagnosis, and optimized treatment, coupled with wider efforts to improve the uptake of HIV services.

Leptomeningeal enhancement (LME) suggests leptomeningeal dissemination (LMD) of tumor cells, which is a complication of end-stage glioblastoma, and is associated with a poor prognosis. However, magnetic resonance imaging (MRI) occasionally indicates the disappearance of peri-brainstem LME after surgical resection of glioblastoma. Since preoperative LMD may affect treatment indications, we aimed to analyze the clinical significance of preoperative LME of the brainstem in glioblastoma.

We retrospectively collected clinical and radiological data from consecutive patients with glioblastoma and preoperative LME of the brainstem, who were treated at our hospital between 2017 and 2020.

Among 112 patients with glioblastoma, nine (8%) showed preoperative LME of the brainstem. In comparison with tumors without LME, tumor size was significantly associated with the preoperative LME of the brainstem (p = 0.016). In addition, there was a trend toward significance for a relationship between deep tumor location and preoperative LME of the brainstem (p = 0.058). Notably, among six patients who underwent surgical resection for glioblastoma with LME of the brainstem, four showed significant radiological disappearance of the LME on postoperative MRI. This suggests that the LME did not result from LMD in these cases. Moreover, these four patients lived longer than would be expected from the presence of LMD. However, this LME disappearance was not observed after biopsy or chemoradiotherapy.

These findings suggest that preoperative LME does not necessarily indicate the presence of untreatable LMD; moreover, LME may disappear after surgical tumor resection. Thus, transient preoperative LME could be attributed to other mechanisms, including impaired venous flow due to intratumoral arteriovenous shunts, which can be resolved by reducing the tumor burden.

The purpose of this study is to investigate whether the presence and pattern of enhancement at the internal acoustic canal (IAC) could help in discriminating between leptomeningeal carcinomatosis (LCa) and meningeal inflammation/infection (MMI).

Magnetic resonance (MR) images of patients with leptomeningeal enhancement were retrospectively evaluated. MR images of the LCa group (n = 33), MMI group (n = 19) and control group (n = 33) were evaluated for the presence, type (moderate/prominent), and localization (unilateral/bilateral) of the IAC enhancement.

The presence of IAC enhancement was significantly more common in patients with LCa (p < 0.001). In 73.7 % of patients with MMI, no contrast enhancement was observed in the IAC. In patients with contrast enhancement in the IAC, the risk of LCa in the etiology is 20 times greater than the risk of having MMI. Seventy-five percent of the IAC enhancement seen in LCa patients and 20 % of the IAC enhancements seen in MMI patients was bilateral. This difference was statistically significant (p = 0.029).

Intense contrast enhancement of the IAC can be a marker for LCa.

Large-scale brain activity mapping is important for understanding the neural basis of behaviour. Electrocorticograms (ECoGs) have high spatiotemporal resolution, bandwidth, and signal quality. However, the invasiveness and surgical risks of electrode array implantation limit its application scope. We developed an ultrathin, flexible shape-changing electrode array (SCEA) for large-scale ECoG mapping with minimal invasiveness. SCEAs were inserted into cortical surfaces in compressed states through small openings in the skull or dura and fully expanded to cover large cortical areas. MRI and histological studies on rats proved the minimal invasiveness of the implantation process and the high chronic biocompatibility of the SCEAs. High-quality micro-ECoG activities mapped with SCEAs from male rodent brains during seizures and canine brains during the emergence period revealed the spatiotemporal organization of different brain states with resolution and bandwidth that cannot be achieved using existing noninvasive techniques. The biocompatibility and ability to map large-scale physiological and pathological cortical activities with high spatiotemporal resolution, bandwidth, and signal quality in a minimally invasive manner offer SCEAs as a superior tool for applications ranging from fundamental brain research to brain-machine interfaces.

Multiple ring-enhancing lesions are commonly experienced group of brain pathologies which we come across in day-to-day practice. Clinical symptoms in these lesions are quite non-specific, and hence, it is difficult to reach a final diagnosis. However, these lesions have a varied group of differential diagnosis and it is sometimes difficult to have an accurate diagnosis on conventional MRI. This article was written with the objective of discussing the demographical study and etiology, clinical diagnosis and management for these patients.

It is a prospective study carried out at the Department of Neurosurgery, Dr. D Y Patil Medical College and Hospital, Pune, from September 2019 to August 2022 and included 50 patients who presented to us multiple ring-enhancing brain lesions.

In our study, 50 patients between age (1-70 years) with multiple ring-enhancing lesions were analyzed. Majority of the patients were between age group 30-39 years. Males (76%) were majority in our study than females (24%). Most common pathology was primary neoplasm (glioma) and metastasis, followed by nine patients of pyogenic abscess and tuberculosis each. Neurocysticercosis was seen in eight patients and three patients were diagnosed with CNS lymphoma. Most of our patients presented with headache (38 patients) and a subset of patients had associated seizures (28 patients). Two patients with primary neoplasm were diagnosed to have WHO grade 3 glioma and seven patients were diagnosed to have WHO grade 4 glioma. Glioblastoma multiforme presented as multifocal and multicentric lesions. Among the patients with primary neoplasm, three patients underwent stereotactic biopsy for diagnosis and the rest of seven patients underwent maximum safe resection followed by chemotherapy and radiotherapy. Ten patients were diagnosed with metastatic lesions, among them six patients underwent stereotactic biopsy for histopathological diagnosis and immunohistochemistry, and rest of the patients were managed on the basis of the primary lesion. Five patients were immune-compromised, among them two patients presented with abscess and three patients presented with primary neoplastic lesion. Thirty-six patients underwent biopsy, among them seven patients underwent frameless, seven patients underwent frame stereotactic biopsy, and the rest 22 patients underwent excision biopsy.

Multiple ring-enhancing lesions of brain pose a challenge in terms of achieving an accurate diagnosis and planning further treatment. It is of utmost importance to have a diagnosis in mind based on radiological investigations, so that surgical intervention can be planned accordingly be it by invasive or minimal invasive techniques. An idea toward the diagnosis also helps in prognosticating these patients which could avoid costly whole-body scans and unnecessary surgical intervention.

Magnetic resonance imaging (MRI) in therapy-naïve intracranial glioma is paramount for neuro-oncological diagnostics, and it provides images that are helpful for surgery planning and intraoperative guidance during tumor resection, including assessment of the involvement of functionally eloquent brain structures. This study reviews emerging MRI techniques to depict structural information, diffusion characteristics, perfusion alterations, and metabolism changes for advanced neuro-oncological imaging. In addition, it reflects current methods to map brain function close to a tumor, including functional MRI and navigated transcranial magnetic stimulation with derived function-based tractography of subcortical white matter pathways. We conclude that modern preoperative MRI in neuro-oncology offers a multitude of possibilities tailored to clinical needs, and advancements in scanner technology (e. g., parallel imaging for acceleration of acquisitions) make multi-sequence protocols increasingly feasible. Specifically, advanced MRI using a multi-sequence protocol enables noninvasive, image-based tumor grading and phenotyping in patients with glioma. Furthermore, the add-on use of preoperatively acquired MRI data in combination with functional mapping and tractography facilitates risk stratification and helps to avoid perioperative functional decline by providing individual information about the spatial location of functionally eloquent tissue in relation to the tumor mass. KEY POINTS::   · Advanced preoperative MRI allows for image-based tumor grading and phenotyping in glioma.. · Multi-sequence MRI protocols nowadays make it possible to assess various tumor characteristics (incl. perfusion, diffusion, and metabolism).. · Presurgical MRI in glioma is increasingly combined with functional mapping to identify and enclose individual functional areas.. · Advancements in scanner technology (e. g., parallel imaging) facilitate increasing application of dedicated multi-sequence imaging protocols.. CITATION FORMAT: · Sollmann N, Zhang H, Kloth C et al. Modern preoperative imaging and functional mapping in patients with intracranial glioma. Fortschr Röntgenstr 2023; 195: 989 - 1000.

To explore the feasibility of MR 3D T1w Sampling Perfection with Application optimized Contrasts by using different flip angle Evolutions (SPACE) sequence imaging in symptomatic CVT diagnose, extracting the imaging features with quantitative analysis.

Fifty-nine patients with suspected CVT with neurological symptoms were retrospectively included in this study. Of them, 35 patients were enrolled in the comparation of diagnostic accuracy between the contrast-enhanced magnetic resonance venograms (CE-MRV) and 3D T1w SPACE imaging. Forty-five patients with 101 involved segments were identified for the quantitative analysis. All MR images were acquired on a 3.0 T MR scanner. The reference standard used in this study was a comprehensive combination of the imaging techniques and clinical information. CVT patients were grouped as acute (≤48 h), subacute (>48 h and ≤30d), and chronic (>30d) clinical phase. CVT segments were grouped based on pre-contrast T1WI, as type A: hypo intense signal; B: heterogeneously hyper intense signal; C: iso intense signal. The feasibility of 3D T1w SPACE imaging for diagnosing CVT was explored. Diagnostic accuracy of T1w SPACE imaging was analyzed and compared with the CE-MRV. The signal intensity of pre-contrast images (SpreCE), signal intensity of post-contrast images (SpostCE), and contrast enhancement (CE) rate, CE rate relative to that of pituitary gland (PG), white matter (WM), gray matter (GM), and normal vein vessel wall (nVVW) were compared based on both patients and segments. The CE rate grade of CVT segments of different imaging types was compared.

The MR 3D T1w SPACE imaging achieved a higher sensitivity and specificity (100%/94.1% and 100%/100% based on patients/segments separately) than that of the CE-MRV (73.9%/56.9% and 83.3%/98.9% based on patients/segments separately). No statistical correlation was found between the imaging types of CVT segments and onset time of clinical symptoms (χ2 = 6.649, P = 0.171). Quantitative analysis showed that the CE rate relative to PG and that to WM were higher in the chronic CVT patients than that in the other two groups (H = 10.330 and P = 0.006, H = 9.898 and P = 0.007, separately). CE rate relative to GM in the chronic group was higher than that in the subacute group (H = 7.143 and P = 0.028). All of the quantitative parameters were statistically different across CVT segments of three imaging types (all P≤0.001).

MR 3D T1w SPACE imaging has the advantage to accurately diagnose CVT of different clinical stages, and identify the involved thrombus segments.

Cerebrovascular complications could occur in 15-57 % of patients with tuberculous meningitis (TBM). It is crucial to rapidly identify TBM patients who are at risk for stroke. This study aimed to find predictors of stroke in patients with TBM.

This systematic review and meta-analysis were done using literature searches through online databases up to April 30th, 2022. Three independent authors performed literature screening, data extraction, and critical appraisal of the studies. Eight studies involving 1535 samples were included.

We analyzed data regarding demographic, comorbidity, clinical presentation, radiologic, and laboratory parameters. Overall, clinical presentation that showed outcome difference was found in patients with findings of vomiting (OR = 2.71, 95 % CI: 1.30-5.63), cranial nerve deficit (OR = 4.10, 95 % CI: 1.83-9.21), focal deficit (OR = 5.56, 95 % CI: 2.24-13.79), and altered consciousness (OR = 1.90, 95 % CI: 1.24-2.92). Some comorbidities showed significant differences such as diabetes mellitus (OR = 2.58, 95 % CI: 1.51-4.41), hypertension (OR = 5.73, 95 % CI: 3.36-9.77), ischemic heart disease (OR = 2.18, 95 % CI: 1.02-4.63), and smoking (OR = 2.65, 95 % CI: 1.22-5.77). Two radiological changes shown to have significantly higher proportions are hydrocephalus (OR = 2.50, 95 % CI: 1.74-3.58) and meningeal enhancements (OR = 3.99, 95 % CI: 1.73-9.20).

Our analysis indicated that clinical presentations of vomiting, cranial nerve deficit, focal deficit, altered consciousness; comorbidity of diabetes mellitus, hypertension, smoking history, ischemic heart disease; and radiological findings of meningeal enhancement and hydrocephalus showed significant association with stroke incidence in tuberculous meningitis.

The purpose is to describe how patients with a late-presenting dural leak (LPDL) after posterior spinal fusion (PSF) was diagnosed and treated at a single institution.

Of the 1991 patients who underwent a PSF between 2010 and 2018, 6 patients were identified with a clinical course consistent with a potential LPDL.

Six patients with median age 16.9 years had onset of headache ranging 1-12 weeks postoperatively (median 6.5 weeks). All six patients presented with positional headache, and half (3/6) presented with emesis. 5/6 patients underwent contrast brain MRI, which demonstrated pachymeningeal enhancement. 4/5 patients with dural enhancement went on to have CT myelogram. Five patients had a CT myelogram, which identified a dural leak in all patients and localized the leak in four of five patients. All patients underwent an epidural blood patch, which resolved the pain in five patients. One patient without relief underwent revision surgery with removal of a medially placed screw and fibrin glue placement resolving symptoms.

Postoperative dural leaks associated with PSF may present in a delayed fashion. The majority of leaks were not associated with screw malposition. In diagnosing patients with suspected LPDL, we suggest brain MRI with contrast as a first step. Most patients with pachymeningeal enhancement shown on contrast brain MRI had dural leaks that were identified through CT myelograms. For patients with a dural leak, if there is no disruption from screws, a blood patch appears to be an effective treatment.

IV.

Multimodal imaging (MMI) has emerged as a powerful tool in clinical research, combining different imaging modes to acquire comprehensive information and enabling scientists and surgeons to study tissue identification, localization, metabolic activity, and molecular discovery, thus aiding in disease progression analysis. While multimodal instruments are gaining popularity, challenges such as non-standardized characteristics, custom software, inadequate commercial support, and integration issues with other instruments need to be addressed. The field of multimodal imaging or multiplexed imaging allows for simultaneous signal reproduction from multiple imaging strategies. Intraoperatively, MMI can be integrated into frameless stereotactic surgery. Recent developments in medical imaging modalities such as magnetic resonance imaging (MRI), and Positron Emission Topography (PET) have brought new perspectives to multimodal imaging, enabling early cancer detection, molecular tracking, and real-time progression monitoring. Despite the evidence supporting the role of MMI in surgical decision-making, there is a need for comprehensive studies to validate and perform integration at the intersection of multiple imaging technologies. They were integrating mass spectrometry-based technologies (e.g., imaging mass spectrometry (IMS), imaging mass cytometry (IMC), and Ion mobility mass spectrometry ((IM-IM) with medical imaging modalities, offering promising avenues for molecular discovery and clinical applications. This review emphasizes the potential of multi-omics approaches in tissue mapping using MMI integrated into desorption electrospray ionization (DESI) and matrix-assisted laser desorption ionization (MALDI), allowing for sequential analyses of the same section. By addressing existing knowledge gaps, this review encourages future research endeavors toward multi-omics approaches, providing a roadmap for future research and enhancing the value of MMI in molecular pathology for diagnosis.

Leptomeningeal myelomatosis is a rare complication of multiple myeloma (<1% of the patients). There was an increase in the incidence of leptomeningeal myelomatosis during the last decade; the prognosis of leptomeningeal myelomatosis remains poor, (overall median survival from the time of diagnosis of 2 months). We discuss a rare case of a monoclonal gammopathy evolving into multiple myeloma and finally into a rapidly progressing leptomeningeal disease. A 76 year-old woman in hematologic follow-up for advanced stage multiple myeloma in sixth-line treatment had an episode of generalized tonic-clonic seizure with sphincter release followed by altered state of consciousness. The unenhanced head CT scan showed a mild enlargement of the ventricular system without intra-axial or extra-axial hemorrhages nor significant changes in brain parenchyma. The subsequent contrast-enhanced brain MRI revealed a widespread nodular leptomeningeal enhancement characterized by contrast-enhancement of the pia mater extended into the subarachnoid spaces of the sulci and cisterns, involving supra- and sub-tentorial regions and the statoacoustic nerve in the inner ear canal bilaterally. The fluid-attenuated inversion recovery MRI images demonstrated an abnormally elevated signal within the sulci in the parieto-occipital regions. The radiological diagnosis of leptomeningeal myelomatosis was made. The patient died 4 days after the examination. In patients with long-lasting multiple myeloma and onset of neurological signs or symptoms, a contrast-enhanced brain MRI should be performed to assess the actual burden of central nervous system involvement in leptomeningeal myelomatosis; CT may provide a clue to the diagnosis when progressive enlargement of the ventricles over time is noted.

To assess the usefulness of post contrast Fluid attenuated inversion recovery (FLAIR), 3D T1-SPACE, and T1W magnetic resonance imaging (MRI) sequences with fat suppression in diagnosis of infectious meningitis.

75 patients with clinical suspicion of meningitis were evaluated with post contrast FLAIR (PC-FLAIR), post contrast T1-SPACE (PC-T1-SPACE), and post contrast T1WI (PC-T1WI). Sensitivity, specificity, positive predictive value, and negative predictive value of individual sequences were assessed.

The sensitivity of PC-FLAIR (88.4%) was greater than PC-T1-SPACE (85.5%) and PC-T1WI (82.6%), considering cerebrospinal fluid (CSF) analysis as gold standard (p < 0.05). Kappa inter-rater agreement between two radiologists was 0.921 for PC-T1-SPACE, 0.921 for PC-T1WI, and 1.0 for PC-FLAIR with a p value <0.05. Both PC-T1-SPACE and PC-FLAIR performed equally in sulcal space enhancement. PC-T1-SPACE and PC-T1WI performed better in evaluation of pachymeningeal enhancement, ependymal enhancement in cases of ventriculitis, whereas PC-FLAIR was more sensitive in assessment of basal cistern enhancement and enhancement along the cerebellar folia.

Meningeal enhancement could be better appreciated in PC-FLAIR image than PC-T1WI and PC-T1-SPACE. Enhancement in PC-T1-SPACE was comparable to that of PC-T1WI. Being a T1 based spin echo sequence, PC-T1-SPACE has all the advantages of PC-T1WI in addition to its ability to differentiate meningeal enhancement from leptomeningeal vessels. Hence, PC-T1WI can be replaced by PC-T1-SPACE and PC-FLAIR can be added to routine MRI protocol in suspected case of meningitis.

Accumulating evidence from recent studies has indicated the importance of studying the interaction between the microvascular and lymphatic systems in the brain. To date, most imaging methods can only measure blood or lymphatic vessels separately, such as dynamic susceptibility contrast (DSC) MRI for blood vessels and DSC MRI-in-the-cerebrospinal fluid (CSF) (cDSC MRI) for lymphatic vessels. An approach that can measure both blood and lymphatic vessels in a single scan offers advantages such as a halved scan time and contrast dosage. This study attempts to develop one such approach by optimizing a dual-echo turbo-spin-echo sequence, termed "dynamic dual-spin-echo perfusion (DDSEP) MRI". Bloch simulations were performed to optimize the dual-echo sequence for the measurement of gadolinium (Gd)-induced blood and CSF signal changes using a short and a long echo time, respectively. The proposed method furnishes a T1-dominant contrast in CSF and a T2-dominant contrast in blood. MRI experiments were performed in healthy subjects to evaluate the dual-echo approach by comparing it with existing separate methods. Based on simulations, the short and long echo time were chosen around the time when blood signals show maximum difference between post- and pre-Gd scans, and the time when blood signals are completely suppressed, respectively. The proposed method showed consistent results in human brains as previous studies using separate methods. Signal changes from small blood vessels occurred faster than from lymphatic vessels after intravenous Gd injection. In conclusion, Gd-induced signal changes in blood and CSF can be detected simultaneously in healthy subjects with the proposed sequence. The temporal difference in Gd-induced signal changes from small blood and lymphatic vessels after intravenous Gd injection was confirmed using the proposed approach in the same human subjects. Results from this proof-of-concept study will be used to further optimize DDSEP MRI in subsequent studies.

Diffusion-restricted (DR) lesions of the splenium are encountered in a wide variety of pathologies, and their significance is often unclear. We sought to report the spectrum of clinical presentations, neuroimaging patterns, and the predictors of radiographic and clinical outcomes from DR splenial lesions.

This was a single-center, retrospective cohort study from January 1, 2009, to August 1, 2020. A consecutive sample of 3,490 individuals who underwent brain MRI with reported corpus callosum lesions during the study period were evaluated for DR lesions in the corpus callosum. DR lesions were defined as increased signal intensity on diffusion-weighted imaging sequences with decreased signal intensity on apparent diffusion coefficient. Patients with prior neurosurgical procedures, hemorrhage-associated DR, anoxic brain injury, and chronic or previously known or characterized disease processes in the corpus callosum were excluded. Clinical and radiologic outcomes were ascertained, including readmissions within 1 year, in-hospital mortality rates, and resolution of DR at first follow-up imaging. Outcomes were defined a priori.

Two hundred patients met criteria for inclusion. The average age was 57 years (standard deviation 19 years). Near half of the patients were women (47%). Encephalopathy (55%), focal weakness (46.5%), and cortical signs (44%) were the most common presenting clinical features. Thirty-five cases (17.5%) had features consistent with cytotoxic lesions of the corpus callosum (CLOCCs). Vascular causes were most frequent (61%), followed by malignancy-related (15%) and trauma (8%). In-hospital mortality occurred in 8.5% of cases, 46.5% were readmitted to the hospital within 1 year, and 49.1% of patients had resolution of the splenial DR at the next scan. Backward stepwise regression models showed that mass effect was negatively associated with splenial DR resolution (odds ratio [OR]: 0.12, confidence interval [CI] 0.03-0.46, p = 0.002). Encephalopathy was significantly associated with in-hospital mortality (OR: 4.50, CI 1.48-17.95, p = 0.007). Patients with a CLOCC had less frequent readmissions at 1-year compared with patients without a CLOCC, p = 0.015.

Vascular DR lesions of the splenium were more common than CLOCCs and other etiologies in this cohort. While splenial DR lesions can present a clinical challenge, their associated clinical and radiographic characteristics may predict outcome and guide prognosis.

The WHO grade and Ki-67 index are independent indices used to evaluate the malignant biological behavior of meningioma. This study aims to develop MRI-based machine learning models to predict the malignant biological behavior of meningioma from the perspective of the WHO grade, Ki-67 index, and their combination.

This multicenter, retrospective study included 313 meningioma patients, of which 70 were classified as high-grade (WHO II/III) and 243 as low-grade (WHO I). The Ki-67 expression was classified into low-expression (n = 216) and high-expression (n = 97) groups with a threshold of 5%. Among them, there were 128 patients with malignant biological behavior whose WHO grade or Ki-67 index increased either or both. Data from Center A and B are were utilized for model development, while data from Center C and D were used for external validation. Radiomic features were extracted from the maximum cross-sectional area (2D) region of Interest (ROI) and the whole tumor volume (3D) ROI using different paraments from the T1, T2-weighted, and T1 contrast-enhanced sequences (T1CE), followed by five independent feature selections and eight classifiers. 240 prediction models were constructed to predict the WHO grade, Ki-67 index and their combination respectively. Models were evaluated by cross-validation in training set (n = 224). Suitable models were chosen by comparing the cross-validation (CV) area under the curves (AUC) and their relative standard deviations (RSD). Clinical and radiological features were collected and analyzed; meaningful features were combined with radiomic features to establish the clinical-radiological-radiomic (CRR) models. The receiver operating characteristic (ROC) analysis was used to evaluate those models in validation set. Radiomic models and CRR models were compared by Delong test.

1218 and 1781 radiomic features were extracted from 2D ROI and 3D ROI of each sequence. The selected grade, Ki-67 index and their combination radiomic models were T1CE-2D-LASSO-LR, T1CE-3D-LASSO-NB, and T1CE-2D-LASSO-LR, with cross-validated AUCs on the training set were 0.857, 0.798, and 0.888, the RSDs were 0.06, 0.09, and 0.05, the validation set AUCs were 0.829, 0.752, and 0.904, respectively. Heterogeneous enhancement was found to be associated with high grade and Ki-67 status, while surrounding invasion was associated with the high grade status, peritumoral edema and cerebrospinal fluid space surrounding tumor were correlated with the high Ki-67 status. The Delong test showed that these significant radiological features did not significantly improve the predictive performance. The AUCs for CRR models predicting grade, Ki-67 index, and their combination in the validation set were 0.821, 0.753, and 0.906, respectively.

This study demonstrated that MRI-based machine learning models could effectively predict the grade, Ki-67 index of meningioma. Models considering these two indices might be valuable for improving the predictive sensitivity and comprehensiveness of prediction of malignant biological behavior of meningioma.

11 C-Methionine (MET)-PET is a useful tool in neuro-oncology. This study aimed to examine whether a combination of diagnostic variables associated with MET uptake could help distinguish between brain lesions that are often difficult to discriminate in conventional CT and MRI.

MET-PET was assessed in 129 patients with glioblastoma multiforme, primary central nervous lymphoma, metastatic brain tumor, tumefactive multiple sclerosis, or radiation necrosis. The accuracy of the differential diagnosis was analyzed using five diagnostic characteristics in combination: higher maximum standardized uptake value (SUV) of MET in the lesion/the mean normal cortical SUV of MET ratio, overextension beyond gadolinium, peripheral pattern indicating abundant MET accumulation in the peripheral region, central pattern denoting abundant MET accumulation in the central region, and dynamic-up suggesting increased MET accumulation during dynamic study. The analysis was conducted on sets of two of the five brain lesions.

Significant differences in the five diagnostic traits were observed among the five brain lesions, and differential diagnosis could be achieved by combining these diagnostic features. The area under the curve between each set of two of the five brain lesions using MET-PET features ranged from .85 to 1.0.

According to the findings, combining the five diagnostic criteria could help with the differential diagnosis of the five brain lesions. MET-PET is an auxiliary diagnostic technique that could help in distinguishing these five brain lesions.

Volumetric TSE (3D-TSE) techniques are increasingly replacing volumetric magnetization-prepared gradient recalled-echo (3D-GRE) sequences due to improved metastasis detection. In addition to providing a baseline for assessing postcontrast enhancement, precontrast T1WI also identifies intrinsic T1 hyperintensity, for example, reflecting melanin or blood products. The ability of precontrast 3D-TSE to demonstrate intrinsic T1 hyperintensity is not clear from the literature; thus, this study compares precontrast 3D-TSE and 3D-GRE sequences for identifying intrinsic T1 hyperintensity in patients with metastatic melanoma.

Patients with metastatic melanoma and previously reported intrinsic T1 hyperintensity were identified. MRIs were performed at 3T including both 3D-GRE (MPRAGE) and 3D-TSE T1 sampling perfection with application-optimized contrasts by using different flip angle evolution (T1-SPACE) sequences precontrast. Axial 1-mm slices of both T1WI sequences were independently reviewed by 2 neuroradiologists, comparing the conspicuity of each lesion between the 2 sequences according to a 5-point scale and assessing whether the intrinsic T1 hyperintensity was attributable to melanin, blood products, or both.

Twenty examinations were performed, with a total of 214 lesions demonstrating intrinsic T1 hyperintensity. Both readers found that intrinsic T1 hyperintensity was less conspicuous with T1-SPACE compared with MPRAGE for most lesions assessed (81.8%, averaged across both readers), including for lesions with intrinsic T1 hyperintensity attributable to melanin and blood products. Intrinsic T1 hyperintensity was rarely more conspicuous on T1-SPACE (1.4%).

Precontrast intrinsic T1 hyperintensity is more conspicuous with MPRAGE than T1-SPACE. In patients with metastatic melanoma, 3D-GRE should be preferred as the precontrast T1WI sequence when both 3D-TSE and 3D-GRE are performed postcontrast and when not administering IV contrast.

Cerebrovascular disease is a significant cause of morbidity and mortality in Africa, and using neuroimaging techniques has improved the diagnosis and management of this disease. However, there is a lack of comprehensive reviews of the role and effectiveness of neuroimaging techniques in the African context.

We reviewed the literature to evaluate the role of neuroimaging in diagnosing and managing cerebrovascular disease in Africa. Our search included electronic databases such as PubMed, Scopus, and Google Scholar from 2000 to April 2023. We included peer-reviewed studies written in English that reported on the use of neuroimaging in diagnosing and managing cerebrovascular disease in African populations. We excluded non-peer-reviewed articles, letters, editorials, and studies unrelated to cerebrovascular disease, neuroimaging, or Africa. A total of 102 potential articles were identified; after applying our exclusion criteria and removing duplicated articles, 51 articles were reviewed.

Our findings suggest that neuroimaging techniques such as CT, MRI, and Skull x-ray play a crucial role in diagnosing and managing cerebrovascular disease in Africa. CT and MRI were the most commonly used techniques, with CT being more widely available and less expensive than MRI. However, challenges to using neuroimaging in Africa include the high cost of equipment and maintenance, lack of trained personnel, and inadequate infrastructure. These challenges limit the widespread use of neuroimaging in diagnosing and managing cerebrovascular disease in Africa.

Neuroimaging techniques are essential for diagnosing and managing cerebrovascular disease in Africa, but challenges to their use must be addressed to improve healthcare outcomes. Our policy recommendations can help improve the availability and accessibility of neuroimaging services in Africa.

Meningeal lesions can be caused by various conditions and pose diagnostic challenges. The authors review the anatomy of the meninges in the brain and spinal cord to provide a better understanding of the localization and extension of these diseases and summarize the clinical and imaging features of various conditions that cause dural and/or leptomeningeal enhancing lesions. These conditions include infectious meningitis (bacterial, tuberculous, viral, and fungal), autoimmune diseases (vasculitis, connective tissue diseases, autoimmune meningoencephalitis, Vogt-Koyanagi-Harada disease, neuro-Behçet syndrome, Susac syndrome, and sarcoidosis), primary and secondary tumors (meningioma, diffuse leptomeningeal glioneuronal tumor, melanocytic tumors, and lymphoma), tumorlike diseases (histiocytosis and immunoglobulin G4-related diseases), medication-induced diseases (immune-related adverse effects and posterior reversible encephalopathy syndrome), and other conditions (spontaneous intracranial hypotension, amyloidosis, and moyamoya disease). Although meningeal lesions may manifest with nonspecific imaging findings, correct diagnosis is important because the treatment strategy varies among these diseases. ©RSNA, 2023 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

This study reports on diffuse leptomeningeal glioneuronal tumor (DL-GNT) in a 29-year-old male. DL-GNT is a rare central nervous system (CNS) tumor mostly seen in children and only few cases have been reported in adult patients. Our patient presented with a chronic headache that lasted for five months. MR imaging showed mild hydrocephalus, multiple rim-enhancing nodular lesions in the suprasellar cistern, diffuse leptomeningeal enhancement in the lumbosacral area, and multiple small non-enhancing cyst-appearing lesions not suppressed on fluid attenuated inversion recovery (FLAIR) images in the bilateral basal ganglia, thalami, and cerebral hemispheres. Under the impression of germ cell tumor with leptomeningeal seeding, the patient underwent trans-sphenoidal tumor removal. DL-GNT was pathologically confirmed and FGFR1 mutation was detected through a next-generation sequencing test. In conclusion, a combination of leptomeningeal enhancement and multiple parenchymal non-enhancing cyst-appearing lesions not suppressed on FLAIR images may be helpful for differential diagnosis despite overlapping imaging features with many other CNS diseases that have leptomeningeal enhancement.

A 61-year-old man from India was admitted to hospital after being found unresponsive by the roadside. He was treated with dual-antiplatelet therapy for an acute coronary syndrome. Ten days into admission, he had mild left-sided face, arm, and leg weakness, which progressed significantly over the next 2 months in association with progressive white matter abnormalities on brain MRI. In this case study, we outline our clinical reasoning, which led to the detection of a rare underlying cause of a devastating neurologic disease. We also present our approach to treatment, which achieved a sustained clinical and radiologic response.