IntroductionAmide proton transfer (APT) imaging is one of the imaging methods in Magnetic Resonance Imaging (MRI). It is a molecular imaging technique that visualizes contrast based on the concentration or exchange rate of amide groups of amino acids, which increases in tumors. Methionine-positron emission tomography (MET-PET), on the other hand, has been found to be useful in the imaging diagnosis of glioma because of its clear contrast in the accumulation of tumor cells. In this study, we compared APT and MET-PET on the basis of pathological diagnostic results and backwardly examined whether APT is useful for the imaging diagnosis of glioma.MethodForty-six patients with malignant glioma (World Health Organization 2016 (WHO2016) Grade: GII/III/IV) and suspected pseudoprogression who underwent APT and MET-PET were included in the study. For APT, APT signals were measured in the tumor region of interest, and for MET-PET, 370 MBq was administered to measure the tumor-to-normal tissue ratio (TNR).ResultIn the correlation verification, the actual APT and TNR were correlated with 2.22 ± 1.01 and 2.58 ± 1.5, respectively (r = 0.6, p < 0.001). The accuracy of the differentiation between GII/III/IV (32 patients) and suspected pseudoprogression (14 patients) by actual APT measurements was verified with a sensitivity of 91% and specificity of 100% at a cutoff value of 1.81. In the validation of malignancy diagnosis, the measured APT value of GII (6 cases) was 2.18 ± 0.43 and the TNR was 3.53 ± 2.12, the measured APT value of GIII (11 cases) was 2.67 ± 0.69 and TNR was 2.81 ± 0.72, and the measured APT value of GIV (15 cases) was 2.99 ± 0.61 and the TNR was 3.44 ± 1.28. The APT measured value and TNR differed significantly in malignancy diagnoses, with higher grades having higher values. Genetic diagnosis validation revealed that the oligodendroglioma group (GII/III: 10 cases) had an APT of 2.37 ± 0.66 and a TNR of 3.52 ± 1.41, while the astrocytoma group (GII/III: 7 cases) had an APT of 2.67 ± 0.45 and a TNR of 2.41 ± 0.87.ConclusionAPT may be comparable to MET-PET in differentiating suspected pseudoprogression and in diagnosing malignancy. Patients with an actual APT of 1.81 or higher should be considered for a treatment plan, whereas follow-up may be an option for those with an APT of 1.81. Although the TNR tends to be higher in the oligodendroglioma group (GII/III), APT, which is not affected by the blood-brain barrier, has less variability in actual measurements and is useful for the imaging diagnosis of glioma.
BackgroundIntracranial arterial stenosis is a major cause of ischemic stroke in Asian populations. High-resolution magnetic resonance imaging (HR-MRI) of the vessel wall is an emerging tool that offers valuable insights.MethodsWe conducted a retrospective study of adult patients (≥18 years) with acute ischemic stroke and M1 MCA stenosis who underwent HR-MRI at the University Medical Center Ho Chi Minh City between January 2019 and May 2025.ResultsSixty-two patients were included (mean age, 56 ± 13 years; male-to-female ratio, 2:1). The average stenosis degree was 66.3 ± 17.5, with severe stenosis in 38.7% of patients. The predominant pattern was eccentric stenosis (80.6%), more frequently observed in older patients. The mean remodeling index was 0.87 ± 0.21, and most cases showed negative remodeling. The majority of lesions at the stenotic site exhibited post-contrast enhancement, most commonly grade 2 enhancement (43.6%). The most frequent cause of stenosis was atherosclerosis (43 cases), followed by dissection (2 cases), Moyamoya disease (1 case), and indeterminate etiology (16 cases). Among infarct-associated atherosclerotic lesions, plaques with intraplaque hemorrhage (58.1%), irregular plaque surface (86.1%), and strong (grade 3) enhancement (46.5%) were observed more frequently than in the small non-infarct-associated incidental group; however, this exploratory comparison was limited by the very small size of the comparator group.ConclusionsHR-MRI of the MCA vessel wall provides detailed information on stenotic lesion characteristics, aiding in the identification of the underlying etiology. These findings highlight the potential role of HR-MRI in stroke diagnosis and risk stratification in Vietnamese patients.
PurposeDifferentiating cerebellopontine meningioma (CPM) from schwannoma (CPS) can be challenging. In this location, schwannomas alter the composition of the perilymphatic fluid differently from meningiomas, which has repercussions on magnetic resonance imaging. This study aims to distinguish between these tumors based on the labyrinthine fluid signal on 3D-CISS.MethodsPatients with histologically confirmed CPM and CPS were selected. Analyses were performed considering visual signal intensity from the vestibule and cochlea, and the signal ratios between the vestibules (aV/uV) and the cochleae (aC/uC) on affected and unaffected sides. The signal intensity ratio between vestibule and cerebellum (aV/aCH), vestibule and cerebrospinal fluid (aV/aCSF), and cochlea and cerebrospinal fluid (aC/aCSF), on affected sides, as well as the vestibule and cerebellum ratio between affected and unaffected sides ([aV/aCH]: [uV/uCH]), were also compared.ResultsStatistically significant differences were demonstrated for visual signal reduction (p < .001) and for aV/uV (p = .005), aC/uC (p < .001), [aV/aCH]: [uV/uCH] (p = .018), aV/aCSF (p = .036), and aC/aCSF (p = .001) ratios, with lower values associated with schwannomas. The aC/aCSF ratio showed the highest accuracy (84.2%), with a cutoff value of 0.63, and the second-largest area under the Receiver Operating Characteristic (ROC) curve (0.791). The visual reduction of cochlear signal showed the second-highest accuracy (83%). The aC/uC ratio demonstrated the largest area under the ROC curve (0.857) and the third-highest accuracy (75.5%), using 0.74 as the cutoff value.ConclusionThe visual reduction of cochlear signal and the aC/uC and aC/aCSF ratios proved to be the most effective parameters for distinguishing CPM from CPS when the labyrinthine fluid is utilized.
IntroductionPosterior circulation aneurysms are particularly challenging to treat due to their anatomical complexity and the high perforator density within this region. The pipeline vantage flow diverter (PVFD) has shown promising results in treating anterior circulation aneurysms. However, its efficacy and safety in treating posterior circulation saccular aneurysms are not well investigated.MethodsSingle-center study reviewed patients with posterior circulation aneurysms treated with the PVFD between September 2021 and March 2024. Patients and aneurysm characteristics, clinical results, and radiological results were documented.Results22 patients harboring 24 aneurysms were identified. All aneurysms had a saccular morphology. Complications included ischemic events in two patients (8.3%), one leading to mRS deterioration from 0 to 3. One cerebral hemorrhage leading to mRS shift from 0 to 1 was also documented. At the latest imaging follow-up available (median 14.3 months), complete aneurysm occlusion (Class I, Raymond-Roy occlusion classification (RROC) was achieved in 50% of the cases, residual neck (Class II) in 41.7%, and residual aneurysm (Class III) in 8.3%. Basilar bifurcation aneurysms had lower complete occlusion rates (RROC I: 33.3%) and higher complication rates (16.7% with mRS shift) compared to other locations. In-stent stenosis was rare (4.5%). A limitation of the study is the retrospective, single-center study design.ConclusionThe PVFD demonstrates high occlusion rates and a favorable safety profile in the treatment of saccular aneurysms in the posterior circulation. However, treatment of basilar bifurcation aneurysms with the PVFD remains challenging due to the complex anatomy and high-flow dynamics in this location.
Despite the exponential growth in academic publications and industrial investments in artificial intelligence (AI) in medical imaging, clinical translation remains disproportionately low. Notably, the absence of internationally recognized guidelines for evaluating AI model performance and ethical considerations creates a critical gap in current practices. In this regard, we aim to offer a practical concise perspective exploring performance challenges to implementation while focusing on their mitigation. The dialog continues in subsequent work (part 2) which focuses on ethical issues. In this part, we explore the challenges inherent to the performance evaluation of AI in radiology, focusing on data heterogeneity, the choice of performance metrics and their interpretability, and data access. By shedding light on these issues and discussing potential opportunities, this work contributes to the ongoing dialog surrounding the practical integration of AI in clinical settings. It highlights the imperative need for established guidelines to ensure the safe and efficient deployment of AI technologies in medical imaging, ultimately bridging the gap between theoretical potential and practical implementation.
Artery of Percheron (AOP) infarction is a rare form of ischemic stroke resulting from the occlusion of a single arterial trunk that supplies both sides of the paramedian thalamus and the midbrain. Its occlusion can lead to bilateral and symmetrical infarctions of the paramedian thalami, and occasionally, the midbrain. Due to its atypical presentation, this condition is often diagnosed late. We report a case of a 39-year-old male with no significant medical history who arrived at the emergency department with drowsiness and confusion. During the physical examination, the patient was drowsy but responsive, with poor speech. Motor deficits in all four limbs were not apparent. Vital signs, routine blood tests, and an initial CT scan were unremarkable. The diagnosis was confirmed the following day through a subsequent CT scan and brain MRI. This case emphasizes the diagnostic challenge posed by AOP infarction and highlights the importance of considering this condition even when initial CT imaging appears normal.
Background and Purpose: Subarachnoid hemorrhage is commonly associated with a venous stroke. In infants with a chronic subdural hemorrhage a laminar SAH is produced by blood leakage from thrombosed cortical veins into a potential subarachnoid space previously unrecognized. This paper discusses how to distinguish a laminar SAH from a subdural hemorrhage. Methods: A retrospective review of 34 selected cases of infant venous stroke in the period 2014-2025 is based on neuroimaging studies. The cases selected are from unsolicited referrals from parents, attorneys, and physicians where caregivers are accused of abusive head trauma. Results: The median age is 3 months old. All 34 infants exhibit a venous stroke defined as the presence of a blood clot(s) in a venous sinus or cortical vein or SAH from a leaking thrombosed cortical vein. 33/34 cases feature an associated chronic subdural hemorrhage/hygroma. Thrombosed veins are located subjacent to the arachnoid membrane. 28/34 cases show multifocal (<2cm diameter) SAHs. 24/34 cases show laminar SAHs (>2cm diameter); 10/24 thin (<3mm) and 14/24 thick (>3mm). Intrasulcal SAH is infrequent. Conclusion: The laminar SAH is a non-gyral SAH distinguished from a subdural hemorrhage by its location and rapid resolution. Its combination with the adjacent chronic subdural hemorrhage is commonly and incorrectly described as a mixed density or layered subdural hemorrhage. The laminar SAH is hypothetically located between the arachnoid membrane and a trabecular coat investing the cortical veins. Alternately, it may suggest existence of a 4th meningeal layer recently discovered by anatomists in animal models.
Magnetic Resonance Elastography (MRE) noninvasively maps brain biomechanics and is highly sensitive to alterations associated with aging and neurodegenerative disease. Most implementations use a single frequency or a narrow frequency band, limiting the analysis of frequency-dependent viscoelasticity parameters. We developed a dual-actuator wideband MRE (5-50 Hz) protocol and acquired wave fields at 13 frequencies in 24 healthy adults (young: 23-39 years; older: 50-63 years). Shear wave speed (SWS) maps were generated as a proxy for stiffness, and SWS dispersion was modeled using Newtonian, Kelvin-Voigt, and power-law rheological models. Whole-brain stiffness declined with age, with the strongest effect observed at low frequencies (5-16 Hz: -0.24%/year; p = 0.038) compared with mid (20-35 Hz: -0.12%/year; p = 0.040) and high frequencies (40-50 Hz: -0.10%/year; p = 0.123). Compared to older brains, younger adults showed 8.96% higher baseline stiffness in the power-law model (p = 0.013) and 8.15-8.39% higher viscosity according to the Newtonian and Kelvin-Voigt model (p < 0.05). White and cortical gray matter exhibited similar age-related decreases, while deep gray matter showed an increase in the power-law exponent (+0.001/year; p = 0.046), suggesting a transition toward more fluid-like properties associated with aging. Wideband MRE revealed frequency-dependent and region-specific biomechanical alterations with aging, with the strongest effects observed at low frequencies. Extending brain MRE into the low frequency regime potentially enhances sensitivity to solid-fluid interactions. Therefore, low frequency MRE may serve as an early biomechanical marker of microstructural brain changes due to aging and neurodegeneration. STATEMENT OF SIGNIFICANCE: Magnetic Resonance Elastography (MRE) is a noninvasive imaging modality that quantifies the mechanical properties of brain tissue. Conventional approaches are typically restricted to single or narrow vibration frequency ranges, limiting their ability to characterize frequency-dependent viscoelastic behavior. In this study, we establish a wideband MRE framework spanning 5-50 Hz and apply it in vivo to healthy adults across different age groups. Our results demonstrate that age-related brain softening is most pronounced at low frequencies, indicating sensitivity to microstructural alterations and potentially enhancing sensitivity to fluid-solid interactions. These findings highlight diagnostic potential of low frequency MRE for advancing biomechanical biomarkers of brain aging and for future applications in early detection of neurodegenerative disease.
Neuroanatomy remains one of the most challenging areas in medical education, including neuroradiology, due to its complexity and limitations of traditional teaching methods. This study proposes a novel approach based on systematic image and video sequences to enhance the presentation, exploration, communication, learning, and teaching of neuroanatomy. Systematic image sequences are ordered sets of spatially and contextually correlated images characterized by five features: anatomical content, parcellation, annotation, location, and dimensionality. Five elementary sequence types are introduced: appearance, contextual, multi-dimensional, dissection, and special, which can be combined into composite (homogeneous/heterogeneous, uni-view/multi-view) sequences. These sequences are presented in interactive, single multi-image, and automated modes, and extended to video formats. The sequences were created using a high-resolution, fully parcellated 3D atlas of the human brain, head, and neck. 12 image sequences (51 images) and two video sequences are presented and discussed, along with references to three major resources of ready-to-use sequences: NOWinBRAIN repository (over 8600 3D neuroimages), ebook Neuroanatomy Made Easy (over 350 sequences), and the latest edition of Gray's Anatomy/Chapter_28. The proposed sequences enhance visualization and understanding of anatomical structures and relationships. Appearance sequences improve recognition through parcellation and labeling, while contextual sequences reveal spatial relationships. Dissection and cortical opening sequences expose otherwise hidden structures, and multi-dimensional sequences bridge 2D radiology with 3D anatomy. Hence, the method elucidates complex anatomical organization, including cortico-vascular relationships, ventricular-venous alignment, and cranial nerve pathways. Overall, systematic image-video sequences provide a conceptually straightforward, easy-to-use, simply integrable, and cost-effective framework enhancing spatial understanding and interpretation, particularly in neuroradiology.
BackgroundIn vascular diseases such as arteriovenous malformations and dural arteriovenous fistulas, rare venous drainage routes can be identified angiographically.Case DescriptionA 50-year-old woman was transported to our hospital after she developed a sudden headache and unconsciousness. Computed tomography showed subarachnoid hemorrhage. A cerebral angiography disclosed an arteriovenous malformation (AVM) at the C2 level and a dural arteriovenous fistula (AVF) at C5/C6. The AVF drained through the posterior spinal vein to the inferior retrotonsillar vein. The AVM drained cranially to the anterior spinal vein flowing into the transverse medullary vein. The transverse medullary vein drained into the inferior retrotonsillar vein through a connecting vein. The connecting vein seemed very unusual.ConclusionsIn this case, a rare collateral vein connecting the transverse medullary vein and inferior retrotonsillar vein was observed.
IntroductionThe deep cerebral venous system plays a critical role in surgical approaches to the pineal and posterior third ventricular regions-areas that are particularly challenging in pediatric neurosurgery. While adult venous anatomy is well described, data on normal pediatric venous development remain scarce. Surgical planning in children often relies on extrapolating adult anatomy, which may not reflect age-related anatomical variations that occur during rapid brain growth.MethodsWe retrospectively analyzed high-resolution 3.0 T contrast-enhanced MRIs from 85 pediatric patients (aged 15 days-17 years) performed at a single tertiary center. Key venous angles (ICV-GV, GV-SS, SS-SSS, BV-GV) and distances (BV-BV, ICV-ICV, ICV-BV) were measured using multiplanar reconstruction. Correlations with age were assessed using Pearson correlation and linear regression. Patients were divided into three age groups (0-3 years, 4-12 years, 13-18 years), and group differences were evaluated with ANOVA and Bonferroni correction.ResultsSignificant age-related variations were identified in the conformation of the deep venous system. The ICV-GV, GV-SS, and SS-SSS angles widened with age (p < .001), while BV-GV angles decreased. BV-BV distance increased progressively from infancy to adolescence (p < .001). The ICV-BV relationship remained stable across age groups. Group comparisons confirmed significant differences between the youngest (0-3 years) and oldest (13-18 years) cohorts for most parameters.ConclusionThe venous anatomy of the pineal region evolves significantly with age. Understanding these changes can optimize preoperative planning and surgical strategies in pediatric patients. These data provide age-specific anatomical references that may support neurosurgeons worldwide, including those working in low-resource settings without routine access to neuronavigation.
Background: Cauda equina syndrome (CES) is a rare but serious neurosurgical emergency. Back pain and sciatica are common presentations to A&E. Get It Right First Time (GIRFT) published guidance in February 2023 regarding the red flag symptoms and symptom duration requiring emergency MRI. This framework has been utilised by the orthopaedic service within our hospital. The aim of this study was to assess whether implementing GIRFT guidance could reduce CES related admissions without impacting the diagnostic yield for identifying this emergency.Methods: Retrospective review of all emergency MRI scans to exclude CES during two 6-month periods. GIRFT guidance was published in February 2023. Period 1 (01/08/2022-31/01/2023) was prior to GIRFT guidance and period 2 (01/08/2024-31/01/2025) was more than 1 year after GIRFT guidance. Statistical analysis was undertaken using Chisquared and Mann-Whitney testing. Results: There were 175 emergency MRI scans to exclude CES during period 1 versus 159 during period 2. After implementation of GIRFT guidance, there was a significant reduction in the percentage of patients requiring admission (42.77% vs 56.57%, p = 0.016) and an increase in the percentage of patients scanned on the day of presentation (61.64% vs 52.57%, p = 0.119). There was no change in the diagnostic yield of scans for identifying CES (4.57% vs 4.4%, p = 1). Conclusion: Our results show that utilisation of the GIRFT guidance reduced CES related admissions without negatively impacting diagnostic yield. These findings highlight the value of implementing GIRFT guidelines in neurosurgical and orthopaedic departments across the country.
Background and purposeInterpretation of imaging findings after radiation can be challenging in patients with high-grade glioma. Appearance of contrast-enhancing lesions during follow-up imaging poses difficulty in differentiating true progression from treatment-related changes. In the current study, we report patterns and clinical outcomes of radiation-induced subependymal enhancement.Materials and methodsPatients with histopathological diagnosis of HGG developing radiation-induced contrast enhancement in the subependymal region were considered in the retrospective study. The subependymal enhancement was required to be in the high-dose region of radiotherapy. Patients underwent multiparametric magnetic resonance imaging (MRI), which included T1-contrast, T2-weighted, perfusion, and spectroscopy. Confirmation of radiation changes rather than disease progression was decided based on regression or stability of concerned findings on follow-up imaging.ResultsThirty-four patients were included in the analysis. The median time from radiotherapy to onset of subependymal enhancement was 15 months. The enhancement pattern was feathery, nodular, and linear in 53%, 35%, and 3% of patients, respectively. A T2-hyperintense signal with a hypointense rim was seen in 74% of patients. Majority of these lesions were isoperfused (26%) or hypoperfused (47%). The median radiological follow-up after onset of subependymal enhancement was 7 months (range 1-61 months). At final follow-up, complete resolution, partial regression, and stable findings of the concerned enhancement were seen in 18%, 38%, and 44%, respectively.ConclusionSubependymal enhancement can be seen following radiation, which should be considered during the evaluation of follow-up imaging. Multiparametric MRI with specific contrast patterns, T2-weighted findings, and perfusion imaging can help identify radiation-induced enhancement.
BackgroundMechanical thrombectomy (MT) is a well-established treatment for acute large-vessel occlusion. While the transfemoral approach (TFA) is the standard, it can be challenging in elderly patients with tortuous vasculature. The transbrachial approach (TBA) offers a shorter and more direct route but is associated with more puncture site complications. This study investigates the effectiveness and feasibility of TBA for right anterior circulation strokes.MethodsA total of 23 patients who underwent MT via TBA between September 2023 and January 2025 were retrospectively analyzed and compared with 23 patients treated via TFA from March 2021 to April 2023. Patient characteristics, procedural times, recanalization rates, and complications were evaluated.ResultsThe TBA group showed a shorter median puncture-to-guiding (PtoG) time (13 vs 16 min) and puncture-to-recanalization (PtoR) time (37 vs 52 min) compared to the TFA group. Successful recanalization (TICI ≥2b) was achieved in 95.7% of TBA cases versus 87.0% in TFA. One minor puncture site complication occurred in the TBA group. In rare instances, catheter kinking at the subclavian-CCA junction was observed. Sheathless technique was employed in most TBA cases to minimize puncture complications.ConclusionTBA is a feasible alternative for MT in right anterior circulation strokes, providing improved procedural efficiency. While associated with a higher rate of puncture complications, TBA offers a practical solution in cases where TFA or TRA may be technically challenging.
BackgroundIschemic stroke, often caused by intracranial atherosclerotic stenosis (ICAS), is a leading cause of disability and death globally. 7T MRI offers improved signal-to-noise ratio (SNR) and contrast, enhancing MRA image quality. This study assessed the accuracy of 7T high-resolution (HR) MRI and time-of-flight MRA (TOF-MRA) in measuring middle cerebral artery (MCA) stenosis compared to digital subtraction angiography (DSA).MethodsIn this prospective observational study, patients, diagnosed with MCA atherosclerotic stenosis, underwent 7T HR-MRI, TOF-MRA and DSA. Spearman correlation analysis was used to assess the linear correlation between HR-MRI, TOF-MRA, and DSA measurements of MCA stenosis. Agreement for stenosis classification data was evaluated using weighted kappa values. Receiver Operating Characteristic (ROC) curves were utilized to predict severe stenosis and occlusion of MCA in HR-MRI and TOF-MRA.ResultsThis study included 86 lesions from 81 patients with MCA atherosclerotic stenosis. The stenosis degree measurements between 7T HR-MRI and DSA indicated a very strong correlation (r = 0.8000; p < .0001). The correlation between 7T TOF-MRA and DSA assessments was high (r = 0.7188; p < .001). A robust correlation between 7T HR-MRI and TOF-MRA evaluations was shown (r = 0.839; p < .0001). 7T TOF-MRA (K = 0.673) demonstrated substantial agreement with DSA measurements, showing slight superiority over HR-MRI (K = 0.589). ROC analysis indicated both 7T HR-MRI and TOF-MRA effectively predicted severe MCA stenosis and occlusion (HR-MRI, AUC: 0.888; TOF-MRA, AUC: 0.878).Conclusions7T HR-MRI and TOF-MRA may emerge as comparable modalities for assessing MCA atherosclerotic stenosis, and HR-MRI allows for precise evaluation through direct visualization of the vessel lumen and plaque.
PurposeOnly limited studies have directly compared apparent diffusion coefficient (ADC) values at term-equivalent age (TEA) between normal term infants and very preterm infants. We hypothesized that regional ADC values at TEA would differ between preterm infants and term infants, even in the absence of MRI-detectable brain injury. The purpose of this study was to compare ADC values at TEA between term infants and preterm infants born at less than 32 weeks of gestation.Subjects and methodsThis retrospective study enrolled consecutive infants who underwent neonatal brain MRI over a 7-year period from 2016 to 2022. From this cohort, very preterm infants were selected after confirmation of normal MRI findings and normal neurodevelopmental outcomes. ADC values were measured at six predefined brain regions. ADC values were compared between term infants and preterm infants, and further subgroup analyses were performed among term, very preterm, and extremely preterm infants.ResultsADC values at the basal ganglia were significantly higher in preterm infants compared with term infants. No significant differences were observed at the other five brain regions. Subgroup analysis among term, very preterm, and extremely preterm infants demonstrated significant differences in basal ganglia ADC values, with both very preterm and extremely preterm infants showing higher ADC values than term infants.ConclusionADC values at the basal ganglia at TEA were significantly higher in preterm infants than in term infants, despite normal conventional MRI findings and favorable neurodevelopmental outcomes. These findings suggest region-specific differences in brain microstructural maturation associated with preterm birth.
Diagnosing Rasmussen encephalitis presents a significant challenge when cortical atrophy is absent on MRI. We present a case of Rasmussen encephalitis in a 13-year-old boy with lack of atrophy and imaging features mimicking glioma, including increased 11C-methionine (MET)-PET uptake, which led to diagnostic uncertainty. The patient had been previously diagnosed with chronic autoimmune encephalitis and epilepsy for about 6 years prior. Initial MRI revealed an FLAIR hyperintensity in the left frontal lobe and basal ganglia region without cortical atrophy, which remained stable for several years. However, 1 year after the last follow-up, the lesion demonstrated progressive enlargement. MRS demonstrated an increased choline/NAA ratio, increased CBF on ASL, and increased accumulation on MET-PET primarily in the gray matter adjacent to the FLAIR hyperintense lesion. Because these imaging characteristics could not rule out the possibility of glioma, we decided to perform open biopsy via a small craniotomy to establish definitive diagnosis while minimizing the burden on the patient. The pathological examination revealed cortical thickening, increased astrogliosis, and CD3+ and CD8+ T-cells infiltration. A final diagnosis of Rasmussen encephalitis was established, with follow-up MRI demonstrating a gradual reduction in the lesion signal intensity. The current case highlights the difficulties of distinguishing Rasmussen encephalitis from glioma in the absence of cortical atrophy, as they share similar MRI features and MET-PET uptake patterns. In such cases, a minimally invasive biopsy is recommended to establish a definitive diagnosis and reduce patient burden.
In this study, we aimed to compare the treatment outcomes of patients with unruptured aneurysms treated using stent-assisted coil embolization with and without systemic heparinization to examine the intraoperative systemic heparinization efficacy. We included 106 consecutive patients enrolled at Fukuoka Neurosurgical Hospital, Japan, between November 2021 and March 2023. The patients were divided into two groups: the systemic heparinization and nonsystemic heparinization groups. Head magnetic resonance imaging (MRI) performed on postoperative day 1 showed that the number of ischemic foci <2 mm was higher in the nonsystemic heparinization group than in the systemic heparinization group, although the difference was not statistically significant (2 [0-6] vs 1 [0-3], P = .0583). No significant between-group difference was observed concerning the incidence of ischemic and hemorrhagic complications. There was no significant between-group difference regarding the modified Rankin scale (mRS) score; however, the systemic heparinization group had a higher proportion of patients with poor outcomes than did the nonsystemic heparinization group, with one (2.4%) patient with an mRS score of 5 and one (2.4%) patient with an mRS score of 6. In conclusion, intraoperative systemic heparinization during stent-assisted coil embolization of unruptured cerebral aneurysms may suppress diffusion-weighted imaging high-signal spots on head MRI performed on postoperative day 1. Moreover, systemic heparinization may worsen the outcomes of hemorrhagic complications.
Arteriovenous fistulas (AVFs) involving the inferior petroclival vein (IPCV) are extremely rare and may mimic cavernous sinus (CS) dural arteriovenous fistulas (DAVF) because of shared venous drainage patterns. A 72-year-old man presented with diplopia and left ocular chemosis. Carotid angiography revealed retrograde venous drainage into the superior ophthalmic vein via the inferior petrosal sinus (IPS) and CS. The initial findings suggested a CS-DAVF; however, three-dimensional angiography, including multiplanar reconstruction and maximum intensity projection analyses, identified shunt pouches in the IPCV and anterior condylar vein. Transvenous embolization via the IPS allowed the selective coil embolization of the IPCV shunt pouch while preserving the IPS. The IPCV-AVF resolved completely. Although the anterior condylar vein dural AVF remained, it was classified as Borden type I and was managed conservatively. The present case highlights the importance of detailed three-dimensional angiographic analysis to distinguish IPCV-AVF from CS-DAVF and guide effective treatment.
BackgroundThis study aims to assess whether T2 relaxometry can distinguish tissue characteristics between high-grade gliomas and non-infiltrative lesions.MethodsWe report our initial experience using the Relaxo LNI software to analyze multi-echo T2 relaxometry magnetic resonance imaging in patients with high-grade gliomas. For comparison, peritumoral T2-hyperintense areas in meningiomas and metastases were used as reference regions for vasogenic edema, based on the established concept that these tumor types typically do not infiltrate adjacent tissue. In contrast, peritumoral hyperintensity observed in high-grade gliomas may represent either vasogenic edema or tumor infiltration.ResultsData from 30 patients were analyzed, including 20 with high-grade gliomas and 10 with metastasis or meningiomas. A statistically significant difference was observed in multi-echo T2 relaxation values between the glioma and non-glioma groups (p < 0.05). Mean T2 relaxation times were longer in the high-grade glioma group than in the non-glioma group (p < 0.05). Within the high-grade glioma group, central regions showed significantly longer mean relaxation times than peripheral regions (p < 0.05).ConclusionOur preliminary findings suggest that T2 relaxometry identifies differences in relaxation profiles between tumor tissue and control edema, indicating potential value in detecting variations in peritumoral tissue composition in high-grade gliomas. However, these results are exploratory and hypothesis-generating, lack histopathological validation, and require further investigation to clarify the role of T2 mapping in preoperative planning.