Neuroradiological Imaging Research Articles

A Comparative Evaluation of Large Language Model Utility in Neuroimaging Clinical Decision Support.

Imaging utilization has increased dramatically in recent years, and at least some of these studies are not appropriate for the clinical scenario. The development of large language models (LLMs) may address this issue by providing a more accessible reference resource for ordering providers, but their relative performance is currently understudied. Evaluate and compare the relative appropriateness and usefulness of imaging recommendations generated by eight publicly available models in response to neuroradiology clinical scenarios. Twenty-four common neuroradiology clinical scenarios were selected which often yield suboptimal imaging utilization. Questions were crafted to assess the ability of LLMs to provide accurate and actionable advice. The LLMs were assessed in August 2023 using natural-language 1-2 sentence queries requesting advice about optimal image ordering given certain clinical parameters. Eight of the most well-known LLMs were chosen for evaluation: ChatGPT, GPT4, Bard (Versions 1 and 2), Bing Chat, Llama 2, Perplexity, and Claude. The models were graded by three fellowship-trained neuroradiologists on whether their advice was "optimal" or "not optimal" according to the ACR Appropriateness Criteria or the New Orleans Head CT Criteria. The raters also ranked the models based on the appropriateness, helpfulness, concision, and source-citations in their response. The models varied in their ability to deliver an "optimal" recommendation based on these scenarios as follows: ChatGPT (20/24), GPT4 (23/24), Bard 1 (13/24), Bard 2 (14/24), Bing Chat (14/24), Llama (5/24), Perplexity (19/24), and Claude (19/24). The median ranks of the LLMs were as follows: ChatGPT (3), GPT4 (1.5), Bard 1 (4.5), Bard 2 (5), Bing Chat (6), Llama (7.5), Perplexity (4), and Claude (3). Characteristic errors are described and discussed. GPT-4, ChatGPT, and Claude generally outperformed Bard, Bing Chat, and Llama 2. This study evaluates the performance of a greater variety of publicly available LLMs in settings that more closely mimic real-world use cases as well as discussing the practical challenges of doing so. This is the first study to evaluate and compare a wide range of publicly available LLMs to determine appropriateness of their neuroradiology imaging recommendations.

Central Nervous System Involvement and Neuroradiological Imaging Insights of Neurocutaneous Melanocytosis in Congenital Melanocytic Nevi

Congenital melanocytic nevi (CMN) are pigmented lesions present at birth, varying widely in size and clinical impact. In rare instances, these nevi become visible during the first months of life, a phenomenon known as tardive melanocytic nevi (tardive CMN). Giant congenital melanocytic nevi (GCMN) are defined as nevi larger than 40 cm in projected adult size (PAS). Their association with the central nervous system (CNS) poses significant risks, including melanoma and neurocutaneous melanocytosis (NCM), where melanocytes infiltrate the CNS, potentially causing seizures, hydrocephalus, and, rarely, CNS melanoma. MRI is recommended for GCMN patients, particularly those with numerous satellite nevi or neurological symptoms, to detect CNS involvement. The Nevosurgery Network recommends MRI examinations in cases of GCMN (>40 cm PAS), the presence of over 20 concomitant nevi, and neurological symptoms requiring clarification. CMN can be associated with melanocyte accumulations and melanin deposits in the brain, spinal cord, and leptomeninges.

Symptomatic Cerebellar Thrombosed Developmental Venous Anomaly: A Case Report

Abstract Background With the rising prevalence of advanced neuroradiological imaging, detection of incidental developmental venous anomalies (DVAs) is more commonplace. DVAs are rarely symptomatic (<2%). Typically, symptoms arise due to flow-related complications or mechanical effects. Of particular concern is venous thrombosis, a frequent flow-related complication, which can cause venous ischemia or haemorrhage. Thus, early recognition and intervention is important. Methods We describe a case of a 54-year-old male, with background of hypertension, presenting three days after sudden onset headache, ataxia, and diplopia. Initial clinical examination revealed bidirectional horizontal gaze-evoked nystagmus, skew deviation, and decreased temperature sensation of the left face. Ophthalmological examination identified left inferior rectus limitation. Results Initial non-contrast CT brain identified hypoattenuation in the right pons, suggestive of sub-acute infarction. Secondary prevention was initiated. Subsequent MRI performed 5 days later revealed hyperattenuation on T2 and FLAIR in the pons, right middle cerebellar peduncle, and right cerebellar hemisphere without restricted diffusion. SWI sequences identified an abnormal venous structure in the right cerebellum, with increased signal within it, suggestive of thrombus. The patient was diagnosed with a thrombosed DVA with associated venous oedema. Symptoms had resolved on dual antiplatelet therapy, without anticoagulation. Conclusion This case highlights the potential for DVAs, generally considered a benign entity, to become symptomatic with associated parenchymal damage and a rare, but important, stroke mimic. Moreover, it underscores the pivotal role of MRI imaging; while a CT scan might have led to the assumption of a subacute infarct, MR imaging led to a complete re-evaluation of the diagnosis in this case.

An Extremely Rare Case of Collision Tumor: A Craniopharyngioma Coexists Pilocytic Astrocytoma

A 21-year-old man presented with a 2-day history of cephalalgia and a 1-day history of nausea and vomiting. Neuroradiologic imaging revealed a lesion in the third ventricle accompanied by hydrocephalus. After undergoing a ventriculoperitoneal shunt procedure, the patient experienced relief from symptoms. One-month post-shunt, we excised the tumor. Histopathological examination identified it as a rare collision tumor, composed of a mixture of craniopharyngioma and pilocytic astrocytoma. This is an exceedingly rare type of tumor, with no similar cases reported in the existing literature.

Isotretinoin‐associated intracranial hypertension: A concise report

AbstractWe present a case of a 24‐year‐old preobese female undergoing isotretinoin treatment for acne vulgaris, who experienced drug‐induced intracranial hypertension (DIIH). Recognizing and addressing this potentially serious adverse effect is essential to prevent severe outcomes, particularly irreversible vision impairment. When suspected, immediate discontinuation of isotretinoin, neuroradiological imaging and urgent ophthalmologic evaluation to rule out papilloedema is imperative. Formulation of alternative treatment strategies, caution while prescribing DIIH‐causing drugs in future patient treatments and proactive reporting of adverse events are integral aspects of its comprehensive management.

Clinical Characteristics and Fatality Risk Factors for Patients with Listeria monocytogenes Infection: A 12-Year Hospital-Based Study in Xi'an, China.

Listeriosis is a severe food-borne disease caused by Listeria monocytogenes infection. The data of listeriosis in Xi'an population are limited. The aim of this study is to evaluate the clinical features and fatality risk factors for listeriosis in three tertiary-care hospitals in Xi'an, China METHODS: The characteristics of demographic data, underlying diseases, clinical manifestations, laboratory indicators, cranial imaging examination, antibiotics therapeutic schemes, and clinical outcomes were collected between 2011 and 2023. Logistic regression analysis was performed. Seventy-one etiologically confirmed listeriosis patients were enrolled, including 12 neonatal and 59 non-neonatal cases. The majority of neonatal listeriosis presented as preterm (50%) and fetal distress (75%). The main clinical manifestations of non-neonatal listeriosis included fever (88%), headache (32%), disorder of consciousness (25%), vomiting (17%), abdominal pain (12%), and convulsions (8%). The fatality rate in neonatal cases was higher than in non-neonatal listeriosis (42 vs. 17%). Although no deaths were reported in maternal listeriosis, only two of 23 patients had an uneventful obstetrical outcome. Five maternal listeriosis delivered culture-positive neonates, three of whom decreased within 1week post-gestation due to severe complications. Twenty-eight cases were neurolisteriosis and 43 cases were bacteremia. Neurolisteriosis had a higher fatality rate compared with bacteremia listeriosis (36 vs. 12%). The main neuroradiological images were cerebral edema/hydrocephalus, intracranial infection, and cerebral hernia. Listeria monocytogenes showed extremely low resistance to ampicillin (two isolates) and penicillin (one isolate). The fatality risk factors were the involvement of the central nervous system, hyperbilirubinemia, and hyponatremia for all enrolled subjects. Hyperuricemia contributed to the elevation of fatality risk in non-neonatal listeriosis. When the patients suffered with symptoms of fever and central nervous system infection, they should be alert to the possibility of listeriosis. Early administration of ampicillin- or penicillin-based therapy might be beneficial for recovery of listeriosis.

Double Metachronous Pituitary Microadenoma: Literature Review and Case Report

Pituitary adenomas, which are benign, slow-growing neoplasms, are commonly associated with hormonal overproduction. They rank as the third most prevalent intracranial tumor, following gliomas and meningiomas. Although double pituitary adenomas are infrequent, they manifest when two adenomas develop within a single pituitary gland. These dual adenomas exhibit typical immunohistochemical and histopathological features. They can be further classified into two distinct types: contiguous and clearly distinct. Neuroradiological imaging facilitates the identification of clearly distinct tumors. We present imaging findings from a rare case of a double pituitary microadenoma. Early diagnosis of this uncommon condition is crucial to prevent potential complications.

Role of artificial intelligence (Google bard) in morphological, histopathological, and radiological image identifications: Objective Structured Practical Examination (OSPE) type-based performance.

To evaluate the role of artificial intelligence (Google Bard) in figures, scans, and image identifications and interpretations in medical education and healthcare sciences through an Objective Structured Practical Examination (OSPE) type of performance. The OSPE type of question bank was created with a pool of medical sciences figures, scans, and images. For assessment, 60 figures, scans and images were selected and entered into the given area of the Google Bard to evaluate the knowledge level. The marks obtained by Google Bard in brain structures, morphological and radiological images 7/10 (70%); bone structures, radiological images 9/10 (90%); liver structure and morphological, pathological images 4/10 (40%); kidneys structure and morphological images 2/7 (28.57%); neuro-radiological images 4/7 (57.14%); and endocrine glands including the thyroid, pancreas, breast morphological and radiological images 8/16 (50%). The overall total marks obtained by Google Bard in various OSPE figures, scans, and image identification questions were 34/60 (56.7%). Google Bard scored satisfactorily in morphological, histopathological, and radiological image identifications and their interpretations. Google Bard may assist medical students, faculty in medical education and physicians in healthcare settings.

Tolosa Hunt Syndrome: An Atypical Presentation of a Rare Condition

Abstract Purpose: Tolosa-Hunt Syndrome (THS) is a rare disorder with signs and symptoms that mimic various other diseases. Diagnosis of THS, especially in atypical cases, can be challenging due to the need to exclude other diseases. Observations: A 59-year-old-male presented with acute vision loss of his left eye preceded by acute worsening of chronic headaches. Additionally, he had near complete ophthalmoplegia of this eye. He underwent extensive workup including numerous hematologic studies, cerebrospinal fluid studies, and neuro-radiological imaging studies. All tests had normal results except for an elevated ESR of 92 mm/hour and an abnormal MRI of the brain and orbits. The MRI revealed the left orbit as abnormal with proptosis and intraconal inflammatory change. It also showed abnormal enhancement of the left orbital apex and adjacent lateral aspect of the left sphenoid sinus. He was diagnosed with THS and rapidly responded to corticosteroid treatment. Conclusions and Importance: THS can be challenging to diagnose because it is a diagnosis of exclusion. An added difficulty with THS is the need to quickly recognize and diagnose it since early treatment with corticosteroids can produce a rapid treatment response and decreases the chance of severe residual symptoms. THS does not usually affect the optic nerve, but optic nerve damage can occur and involvement of the optic nerve further increases the urgency of diagnosing it and promptly initiating treatment.

Virtual Reality Planning of Microvascular Decompression in Trigeminal Neuralgia: Technique and Clinical Outcome.

A neurovascular conflict (NVC) is considered the cause of trigeminal neuralgia (TN) in 75% of cases, and if so, a microvascular decompression (MVD) can lead to significant pain relief. A reliable preoperative detection of NVC is essential for clinical decision-making and surgical planning, making detailed neuroradiologic imaging an important component. We present our experiences and clinical outcomes with preoperative planning of the MVD procedure in a virtual reality (VR) environment, based on magnetic resonance imaging (MRI) including magnetic resonance angiography (MRA) and magnetic resonance venography (MRV) sequences. We analyzed the data of 30 consecutive MVDs in patients treated for TN, in a retrospective single-surgeon (R.A. Kockro) study. Out of the 30 cases, 26 were included. Preoperatively, MRA/MRV and MRI series were fused and three dimensionally reconstructed in a VR environment. All critical structures such as the trigeminal nerve as well as the arteries and veins of the cerebellopontine angle, the brainstem, the neighboring cranial nerves, and the transverse and sigmoid sinus were segmented. The NVC was visualized and a simulation of a retrosigmoid approach, with varying trajectories, to the NVC was performed. The intraoperative findings were then compared with the data of the simulation. The clinical outcome was assessed by a detailed review of medical reports, and follow-up-interviews were conducted in all available patients (20/26). The VR planning was well integrated into the clinical workflow, and imaging processing time was 30 to 40 minutes. There was a sole arterial conflict in 13 patients, a venous conflict in 4 patients, and a combined arteriovenous conflict in 9 patients. The preoperative simulations provided a precise visualization of the anatomical relationships of the offending vessels and the trigeminal nerves as well as the surrounding structures. For each case, the approach along the most suitable surgical corridor was simulated and the exact steps of the decompression were planned. The NVC and the anatomy of the cerebellopontine angle as seen intraoperatively matched with the preoperative simulations in all cases and the MVC could be performed as planned. At follow-up, 92.3% (24/26) of patients were pain free and all the patients who completed the questionnaire would undergo the surgery again (20/20). The surgical complication rate was zero. Current imaging technology allows detailed preoperative visualization of the pathoanatomical spatial relationships in cases of TN. 3D interactive VR technology allows establishing a clear dissection and decompression strategy, resulting in safe vascular microsurgery and excellent clinical results.

Automated volumetry of meningiomas in contrast-enhanced T1-Weighted MRI using deep learning

Background: Meningiomas are among the most common intracranial tumors. In these tumors, volumetric assessment is not only important for planning therapeutic intervention but also for follow-up examination.However, a highly accurate automated volumetric method for meningiomas using single-modality magnetic resonance imaging (MRI) has not yet been reported. Here, we aimed to develop a deep learning-based automated volumetry method for meningiomas in MRI and investigate its accuracy and potential clinical applications. Methods: For deep learning, we used MRI images of patients with meningioma who were referred to Osaka University Hospital between January 2007 and October 2020. Imaging data of eligible patients were divided into three non-overlapping groups: training, validation, and testing. The model was trained and tested using the leave-oneout cross-validation method. Dice index (DI) and root mean squared percentage error (RMSPE) were measured to evaluate the model accuracy. Result: A total of 178 patients (64.6 ± 12.3 years [standard deviation]; 147 women) were evaluated. Comparison of the deep learning model and manual segmentation revealed a mean DI of 0.923 ± 0.051 for tumor lesions. For total tumor volume, RMSPE was 9.5 ± 1.2%, and Mann–Whitney U test did not show a significant difference between manual and algorithm-based measurement of the tumor volume (p = 0.96). Conclusion: The automatic tumor volumetry algorithm developed in this study provides a potential volume-based imaging biomarker for tumor evaluation in the field of neuroradiological imaging, which will contribute to the optimization and personalization of treatment for central nervous system tumors in the near future

Role of Neuroradiological Imaging in Progressive Sensorineural Hearing Loss: A Retrospective Study.

Our aim was to determine prevalence and type of neuro-radiological lesions detected on screening Magnetic Resonance Imaging (MRI) of brain in patients presenting with progressive sensorineural hearing loss in otorhinolaryngology clinic. This retrospective study included 96 screening magnetic resonance imaging MRI brain scans of patients who presented with progressive sensorineural hearing loss in department of otorhinolaryngology. The clinical and radiological data was collected and analysed. Out of 96 screening MRI brain, 19 (19.8%) had positive findings. The commonest imaging finding was presence of vascular loop around facial and vestibulocochlear nerve root complex in 9 cases (9.4%) followed by presence of a cerebellopontine angle lesions in 5 cases (5.2%). The mean age of all patients was 48.5 years and those with positive screening MRI was 40.6 years. A gender gap was noticed with female being 22 (22.9%) in number against 74 (77.1%) males. This is the first retrospective study to determine prevalence and type of neuro-radiological lesions detected on screening magnetic resonance imaging in patients with progressive sensorineural hearing loss. We recommend screening MRI brain in patients with progressive SNHL aged below 60 years and all the described neuroradiological finding provide differential diagnosis. Definition and classification of progressive sensorineural hearing loss should be formulated to standardize the management. Further multi-institutional studies are required to identify social, occupational, genetic, or other factors that can cause gender disparity in patients with progressive SNHL.

Post Stroke, Is Perimetry Necessary? A Case Report

Abstract
 Introduction : Stroke are generally associated with peripheral visual field loss. Three out of four stroke patients report some form of disability, one of which is visual impairment. Approximately 16% of these patients have a homonymous visual field defect poststroke. These vision problems can lead to difficulty carrying out a lot of daily tasks and activities, such as driving. This report tries to define the diagnostic flow to determine the exact type and lesion.
 Case Illustration : Male, 61 years old, came to Universitas Sumatera Utara Hospital with visual field loss in both eyes. Two months ago, he was diagnosed with ischemic stroke and treated with Aspirin 80 mg, with no limbs disability right now. He also had hypertension and treated with Amlodipine 10 mg. VOD: 6/60 with BCVA S-2.00 6/7,5, VOS: 6/60 with BCVA S-2.00 6/7.5. With confrontation test and perimetry, defect was found in medial visual field OD and lateral visual field OS. Hess screen and Amsler Grid was normal. Head CT-Scan was performed with multiple infarcts, mainly in right occipital lobe. The patient was diagnosed with Incomplete Hemianopia, Left Congruous Homonymous Hemianopia with Macular Sparing, and treated with Citicholine 1000 mg once daily.
 Discussion
 Conclusion : In stroke patients with homonymous visual field loss, visual field testing with detailed evaluation of visual field defect can determine the lesion location, and neuro-radiological imaging was necessary to assess visual pathway. It’s important for educate the patients, diagnostic and prevent the stroke recurrent.

Orbital tumors

Orbital tumours include a variety of orbital diseases of different origins. In the case of malignant orbital tumours, early detection is important so that treatment can be initiated promptly. Neuroradiological imaging, in particular magnetic resonance imaging (MRI), plays an important role in the diagnostic of orbital tumours. In adults, lymphoproliferative diseases, inflammations and secondary orbital tumours are most frequently found, whereas in children mostly dermoid cysts, optic gliomas and capillary haemangiomas are found. Optic glioma is a pilocytic astrocytoma and accounts for two thirds of all primary optic tumours. Optic nerve sheath meningiomas mostly affect middle-aged women. In childhood, retinoblastoma is the most common intraocular tumour. This is an aggressive malignant tumour which can occur unilaterally or bilaterally. Based on the imaging findings, differential diagnoses can usually be easily narrowed down using criteria such as age of manifestation, frequency, localisation and imaging characteristics.

Fractal Analysis in Clinical Neurosciences: An Overview.

Over the last years, fractals have entered into the realms of clinical neurosciences. The whole brain and its components (i.e., neurons and astrocytes) have been studied as fractal objects, and even more relevant, the fractal-based quantification of the geometrical complexity of histopathological and neuroradiological images as well as neurophysiopathological time series has suggested the existence of a gradient in the pattern representation of neurological diseases. Computational fractal-based parameters have been suggested as potential diagnostic and prognostic biomarkers in different brain diseases, including brain tumors, neurodegeneration, epilepsy, demyelinating diseases, cerebrovascular malformations, and psychiatric disorders as well. This chapter and the entire third section of this book are focused on practical applications of computational fractal-based analysis into the clinical neurosciences, namely, neurology and neuropsychiatry, neuroradiology and neurosurgery, neuropathology, neuro-oncology and neurorehabilitation, neuro-ophthalmology, and cognitive neurosciences, with special emphasis on the translation of the fractal dimension and other fractal parameters as clinical biomarkers useful from bench to bedside.

Relationship between paramacular thinning, cerebral vasculopathy, and hematological risk factors in sickle cell disease.

To identify risk factors for sickle cell maculopathy due to hematological parameters (especially anemia and hemolysis) or cerebral vasculopathy. This retrospective study was conducted at a Referral Center. The follow-up included optical coherent tomography/optical coherent tomography angiography, neuro-radiological imaging, and a hematological assessment (hemoglobin, hemoglobin S level, reticulocytes, mean corpuscular volume, bilirubin, and lactate dehydrogenase). Hundred and thirty-two sickle cell patients were included. Maculopathy was observed in 127 eyes of SS patients and 10 eyes of SC patients (p < 0.001), unrelated to peripheral retinopathy. Cerebral vasculopathy was more frequent in SS patients (p < 0.001) and was also associated with the presence of maculopathy (p = 0.049), and it was related to peripheral retinopathy (p < 0.001). All biological parameters significantly differed according to the genotype (p < 0.001) but not according to the presence of cerebral vasculopathy or maculopathy. In the multivariate analysis, reticulocytes and bilirubin were associated with the presence of cerebral vasculopathy and maculopathy. The data obtained were consistent with the role of anemia or hemolysis markers in cerebral vasculopathy and macular involvement. As a trend of hemolysis appears to be a risk factor for these complications, this validates the use of preventive plasmapheresis in these patients.

NEURO-CRITICAL CARE UNIT OR POST-ANESTHESIA CARE UNIT RECOVERY? ANALYSIS OF 24-HOUR OUTCOMES FOLLOWING 1078 ADULT BRAIN TUMOR SURGERIES

Abstract Post-craniotomy recovery in a neuro-critical care unit (NCCU) has been routine for most patients. There is no evidence to support this practice. To address this, we assessed the development of post-operative adverse events in brain tumor resection patients surveilled in the NCCU or the post-anesthesia care unit (PACU). METHODS: All brain tumor craniotomies performed between 2016-2021 (KP) were reviewed. Inclusion criteria were: age &amp;gt;18; craniotomy for biopsy or resection of intracerebral or extracerebral tumors. Cohorts were divided into two groups based on recovery destination: NCCU or PACU. Past medical history, pre- and post-operative neuroradiological imaging, surgical resection features, and neuropathology results were reviewed for both groups. RESULTS: There were 681 patients in NCCU group and 397 in the PACU group. Mean ages were 55.6 (NCCU) and 59.7 (PACU) (p &amp;lt;0.001). The American Society of Anesthesiologists (ASA) class was not significantly different between groups (p=0.89). Median recovery time in the NCCU group was 19 hours, and 4 hours in the PACU group. The incidence of adverse events within 24 hours post- surgery was 0.04 in NCCU group and 0.03 in PACU group (p=0.46). Post-operative hospital stay was 9.5 days in the NCCU group and 8.5 days in PACU group (p &amp;lt;0.001). CONCLUSION: The incidence of adverse events within 24 hours post brain tumor surgery is not different between patients being surveilled for a long period in a NCCU, or a short period in a PACU.

Use of Large Language Models to Predict Neuroimaging

PurposeLarge language models (LLMs) have demonstrated a level of competency within the medical field. The aim of this study was to explore the ability of LLMs to predict the best neuroradiologic imaging modality given specific clinical presentations. In addition, the authors seek to determine if LLMs can outperform an experienced neuroradiologist in this regard. MethodsChatGPT and Glass AI, a health care–based LLM by Glass Health, were used. ChatGPT was prompted to rank the three best neuroimaging modalities while taking the best responses from Glass AI and the neuroradiologist. The responses were compared with the ACR Appropriateness Criteria for 147 conditions. Clinical scenarios were passed into each LLM twice to account for stochasticity. Each output was scored out of 3 on the basis of the criteria. Partial scores were given for nonspecific answers. ResultsChatGPT and Glass AI scored 1.75 and 1.83, respectively, with no statistically significant difference. The neuroradiologist scored 2.20, significantly outperforming both LLMs. ChatGPT was also found to be the more inconsistent of the two LLMs, with the score difference between both outputs being statistically significant. Additionally, scores between different ranks output by ChatGPT were statistically significant. ConclusionsLLMs perform well in selecting appropriate neuroradiologic imaging procedures when prompted with specific clinical scenarios. ChatGPT performed the same as Glass AI, suggesting that with medical text training, ChatGPT could significantly improve its function in this application. LLMs did not outperform an experienced neuroradiologist, indicating the need for continued improvement in the medical context.

Retiform endothelial hyperplasia mimicking cavernous malformation as a late complication of Gamma Knife radiosurgery.

Gamma Knife radiosurgery (GKRS) is a powerful tool for the management of arteriovenous malformations; however, newly formed mass lesions resembling cavernous malformations are a rare late complication of GKRS. In this retrospective study, the authors tried to clarify the unique histological features of these mass lesions. The authors retrospectively reviewed the clinical course of 889 patients who had undergone GKRS for arteriovenous malformations at their institute from 1991 to 2021. Among the 848 patients who had been followed up periodically with neuroradiological imaging, 37 developed a mass lesion mimicking a cavernous malformation and underwent surgical removal of the lesion. The median volume of the original nidus was 3.7 cm3 (range 0.07-30.5 cm3), and the median prescription dose was 21 Gy (range 12-25 Gy). The histological characteristics and radiological and clinical features of the 37 patients were investigated. Histological examination showed an organized hematoma and a structure termed "retiform endothelial hyperplasia" (RFEH) consisting of endothelium forming multiple lumen-like vascular channels mimicking cavernous malformations but lacking the subendothelial connective tissue that forms the typical vascular wall structure found in cavernous angioma and capillary telangiectasia. RFEH was detected a median of 10.8 years (range 3.2-27.4 years) after GKRS. Neuroimaging showed hematoma surrounded by massive brain edema in all 37 patients. Symptoms caused by mass effect of the lesion and perifocal edema worsened relatively rapidly but completely disappeared after surgery. No recurrence or morbidity occurred after the surgery. The delayed formation of RFEH that is mimicking a cavernous malformation neuroradiologically but is histologically distinct from a vascular malformation is a potential complication of GKRS. Its progressive clinical course suggests that surgical removal should be considered for symptomatic patients and/or patients with an apparent radiological mass sign.

Revolutionizing pediatric neuroimaging: the era of CT, MRI, and beyond.

To review the evolution of cross-sectional imaging in pediatric neuroradiology from early developments to current advancements and future directions. Information was obtained through a PubMed literature search as well as referenced online resources and personal experience from radiologists currently practicing pediatric neuroimaging and those who experienced the era of nascent cross-sectional imaging. The advent of computed tomography (CT) and magnetic resonance imaging (MRI) in the 1970s and 1980s brought about a revolutionary shift in the field of medical imaging, neurosurgical and neurological diagnosis. These cross-sectional imaging techniques ushered in a new era by enabling the visualization of soft tissue structures within the brain and spine. Advancements in these imaging modalities have continued at a remarkable pace, now providing not only high high-resolution and 3-dimensional anatomical imaging, but also functional assessment. With each stride forward, CT and MRI have provided clinicians with invaluable insights, improving the accuracy and precision of diagnoses, facilitating the identification of optimal surgical targets, and guiding the selection of appropriate treatment strategies. This article traces the origins and early developments of CT and MRI, chronicling their journey from pioneering technologies to their current indispensable status in clinical applications and exciting possibilities that lie ahead in the realm of medical imaging and neurologic diagnosis.