Contrast-enhanced Magnetic Resonance Imaging Research Articles

Prognosis of asymptomatic endolymphatic hydrops in healthy volunteers: A five-year cohort study.

This study aimed to clarify the prognosis of asymptomatic endolymphatic hydrops (EH) in healthy volunteers via five-year follow-ups with inner ear magnetic resonance imaging (MRI). Inner ear MRI was performed on 115 participants recruited as controls in a previous study on Meniere's disease. The endolymphatic space was visualized using Naganawa's method of contrast-enhanced MRI with intravenous gadolinium injection and evaluated using Nakashima's method of 2D imaging analysis. Cochlear or vestibular EH was present in 7.0% of participants (n = 8), with all cases being unilateral (laterality), moderate (severity), and asymptomatic (onset). Only cochlear-localized EH, only vestibular-localized EH, and both EH were present in 1.7% (n = 2) (C group), 4.3% (n = 5) (V group), and 0.9% (n = 1) (CV group) of participants, respectively. Conducting inner ear MRI after 5 years showed that EH had almost disappeared in two participants in the C and V groups (4/8, 50.0%). EH was still present in three participants in the V group and one in the CV group (4/8, 50.0%). One participant in the V group and another in the CV group presented with residual inner ear EH and developed typical symptomatic Meniere's disease (2/8, 25.0%). Approximately 7% of healthy participants showed asymptomatic EH. Therefore, EH is not the definitive marker for making a diagnosis of Meniere's disease or the suitable predictor for the development of Meniere's disease. Among these participants, 25% maintained EH and subsequently developed typical Meniere's disease within the next 5 years. Schellong-positive participants maintained persistent EH in the inner ear, and participants with higher scores on the self-rating depression scale developed Meniere's symptoms after 5 years. 2a.

New strategy of LI-RADS v2018 to improve the sensitivity for small hepatocellular carcinoma ≤ 3.0 cm on extracellular-contrast enhanced MRI

IntroductionWe aimed to modify LI-RADS version 2018 to improve sensitivity and determine the value of the combination of high alpha-fetoprotein (AFP) levels for small HCC (sHCC, ≤ 30 mm) diagnosis. MethodsA total of 984 patients at high risk for HCC, with 1204 observations (including 997 small observations ≤ 30 mm), who underwent extracellular contrast-enhanced MRI were enrolled from five independent centers. Blinded readers evaluated the LI-RADS features and categorized each observation according to the LI-RADS v2018, modified LI-RADS and EASL. Odds ratios of LI-RADS major features (MFs) and several high AFP levels for sHCC diagnosis were analyzed using multivariable logistic regression. The modified LR-5 criteria was developed by including no APHE at any size with two MFs, and non-rim APHE with one MF (≥ 10 mm) or with two MFs (< 10 mm). The diagnostic performance of each version of the LR-5 was compared using generalized estimating equations. ResultsAPHE, washout, enhancing capsule and five high AFP levels were independently associated with sHCC. In three datasets, the modified LI-RADS had higher sensitivities for sHCC (76.8 ∼ 85.5 % vs. 73.7 ∼ 75.9 %, P < 0.05) to the LR-5 v2018. The modified LI-RADS with AFP ≥ 200 ng/mL as an additional feature or as an alternative to threshold growth provided higher sensitivities for sHCC than LI-RADS v2018 (82.1 ∼ 90.1 % vs. 73.7 ∼ 75.9 %, all P < 0.05), modified LI-RADS (82.1 ∼ 90.1 % vs. 76.8 ∼ 85.5 %, all P < 0.05) and EASL version 2018 (82.1 ∼ 90.1 % vs. 73.3 ∼ 74.7 %, all P < 0.05), with comparable specificities (all P > 0.05). ConclusionThe new strategy of LI-RADS v2018 provides significantly higher sensitivity and comparable specificity than those of LI-RADS v2018 for sHCC diagnosis on ECA-MRI.

Diagnostic Efficacy of Multimodal Ultrasound for Mass and Non-Mass Enhancements in Dynamic Contrast-Enhanced MRI of Idiopathic Granulomatous Mastitis and Breast Cancer

PurposeIdiopathic granulomatous mastitis (IGM) poses diagnostic challenges due to its diverse clinical and radiological presentations, often mimicking malignancies. This study aimed to assess the diagnostic efficacy of multimodal ultrasound for mass and non-mass enhancements in Dynamic Contrast-Enhanced MRI (DCE-MRI) of IGM and breast cancer. MethodsA retrospective analysis involved patients confirmed histopathologically with IGM and BC. All patients underwent conventional ultrasound (C-US), ultrasound elastography (UE), contrast-enhanced ultrasound (CEUS), and DCE-MR examinations. Blind experienced radiologists assessed imaging findings. Diagnostic accuracy, sensitivity, and specificity were calculated for mass and non-mass enhancements. ResultsFor mass enhancements (ME), multimodal ultrasound demonstrated strong efficacy (AUC = 0.8651, 95% CI: 0.7431 to 0.9871), exhibiting high sensitivity (83.3%) and specificity (92.4%) in differentiating IGM from breast cancer. However, for non-mass enhancements (NME), multimodal ultrasound showed limited accuracy (AUC = 0.6306) with lower sensitivity (65.6%) and specificity (81.2%) in distinguishing between IGM and breast cancer. ConclusionMultimodal ultrasound displayed good diagnostic efficacy for mass enhancements in DCE-MRI for idiopathic granulomatous mastitis and breast cancer, while for non-mass enhancement patterns, DCE-MRI remains the most valuable radiological modality for comprehensively assessing this condition's complexities.

Predictive value of contrast-enhanced MRI for the regrowth of residual uterine fibroids after high-intensity focused ultrasound treatment.

To investigate whether the signal intensity (SI) ratio of residual fibroid (RF) to myometrium using Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI) could predict fibroid regrowth after high-intensity focused ultrasound (HIFU) treatment. A retrospective analysis was conducted among 164 patients with uterine fibroids who underwent HIFU. To predict the RF regrowth, the SI perfusion parameters were quantified using the RF-myometrium SI ratio on CE-MRI on day 1 post-HIFU and then compared with the fibroid-myometrium SI ratio on the T2-weighted image (T2WI) and Funaki classification 1 year later. Thirty cases from another center were used as an external validation set to evaluate the performance of RF-myometrium SI ratio. The predictive performance of the RF-myometrium SI ratio on CE-MRI on day 1 post-HIFU (Area Under Curve, AUC: 0.869) was superior to that of the preoperative and postoperative fibroid-myometrium SI ratios on the T2WI (AUC: 0.724, 0.696) and Funaki classification (AUC: 0.663, 0.623). Multivariate analysis showed that the RF- myometrium SI ratio and RF thickness were independent factors. The RF-myometrium SI ratio reflects the long-term rate of re-intervention (r = 0.455, p < 0.001). The RF-myometrium SI ratio on CE-MRI exhibits greater accuracy in predicting RF regrowth compared to the SI classification and the SI ratio on T2WI. The ratio of residual uterine fibroid to myometrial signal intensity on contrast-enhanced (CE)-MRI can reflect residual blood supply, predict regrowth of fibroids, and thus reflect long-term re-intervention rate and recovery situation of clinical high-intensity focused ultrasound (HIFU) treatment. Contrast-enhanced (CE)-MRI can indicate the blood supply of residual uterine fibroids after high-intensity focused ultrasound (HIFU) treatment. The predictive capability of CE-MRI ratio surpasses T2WI ratio and the Funaki. Residual fibroids can serve as a measure of the long-term efficacy of HIFU.

Misdiagnosis in breast imaging: a statement paper from European Society Breast Imaging (EUSOBI)-Part 2: Main causes of errors in breast imaging and recommendations from European Society of Breast Imaging to limit misdiagnosis.

Breast cancer is one of the leading causes of negligence claims in radiology. The objective of this document is to describe the specific main causes of errors in breast imaging and provide European Society of Breast Imaging (EUSOBI) recommendations to try to minimize these. Technical failures represent 17% of all mammographic diagnostic negligence claims. Mammography quality control protocol and dedicated training for technologists and radiologists are essential. Lack of consideration of the clinical context is a second critical issue, as a clinical abnormality is found in 80% of malpractice claims. EUSOBI emphasizes the importance of communication and clinical examination before the diagnostic investigation. Detection errors or misapplications of the lexicon or Breast Imaging Reporting Data System (BI-RADS) score account for 5% of malpractice claims and should be reduced by limiting radiologists' distraction or fatigue, and being aware of satisfaction of search errors and the importance of a personal systematic review. Errors related to pathological concordance and MDT review can be limited by the use of markers after biopsy and the use of standardized reports, which can aid communication with other specialities. Finally, errors related to tumor or patient factors should be discussed, considering the use of contrast-enhanced mammography and magnetic resonance imaging. Several factors are responsible for misdiagnosis in breast cancer, including errors in the practice of the technician and/or radiologist (technical failures, lack of consideration of the clinical context, incorrect application of the BI-RADS score, false reassurances), lack of communication with other specialists or with the patient, and the type of tumor and breast parenchyma. Question What factors most contribute to and what implications stem from misdiagnosis in breast imaging? Findings Ongoing training and education for radiologists and other healthcare providers, as well as interdisciplinary collaboration and communication is paramount. Clinical relevance Misdiagnosis in breast imaging can have significant implications for patients, healthcare providers, and the entire healthcare system.

Enhancing bone metastasis prediction in prostate cancer using quantitative mpMRI features, ISUP grade and PSA density: a machine learning approach.

Bone metastasis is a critical complication in prostate cancer, significantly impacting patient prognosis and quality of life. This study aims to enhance bone metastasis prediction using machine learning (ML) techniques by integrating dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) perfusion features, International Society of Urological Pathology (ISUP) grade, and prostate-specific antigen (PSA) density. A retrospective analysis was conducted on 122 patients with histopathologically confirmed prostate cancer who underwent multiparametric prostate magnetic resonance imaging (mpMRI). Quantitative mpMRI features, PSA density, and ISUP grades were extracted and normalized. The dataset was balanced using oversampling and divided into training (70%) and test (30%) sets. Various ML models were developed and evaluated using area under the curve (AUC) metrics. Bone metastases were present in 26 patients (21.3%) at diagnosis. IAUGC and MaxSlope showed a statistically significant association with bone metastasis (p = 0.035, p = 0.050 respectively). The optimal PSA density cut-off value of 0.24 yielded a sensitivity of 0.88, specificity of 0.60, and AUC of 0.77. Machine learning models were developed using the dataset created with IAUGC, MaxSlope, ISUP grade, and PSA density values. Among the ML models, XGBoost demonstrated superior performance with validation and test AUCs of 91.5% and 92.6%, respectively, along with high precision (93.3%) and recall (93.1%). Integrating quantitative mpMRI features, ISUP grade, and PSA density through machine learning algorithms, particularly XGBoost, significantly improves the accuracy of bone metastasis prediction in prostate cancer patients. This approach can potentially reduce the need for additional imaging modalities and associated radiation exposure.

Lacrimal gland enlargement in thyroid eye disease.

This study aimed to investigate lacrimal gland (LG) enlargement in thyroid eye disease (TED) patients on magnetic resonance imaging (MRI). A retrospective review was conducted on TED patients who had undergone fat-suppressed contrast-enhanced T1-weighted MRI of the orbits. The lacrimal gland was segmented on OsiriX in consecutive axial and coronal slices to determine its volume. Enlargement was defined as a volume greater than 1100mm3, based on previous normative data. Asymmetric enlargement was defined if one side was enlarged but the contralateral side was not. Clinical data including presentation (active/inactive) and presence or absence of dysthyroid optic neuropathy was evaluated. The study population consisted of 88 orbits from forty-four patients with a mean age of 53 ± 15years, with 29 (65%) being female. Twelve patients (27%) had LG enlargement, with eight (18%) having bilateral enlargement and four (9%) having asymmetric enlargement. There was no significant difference in age (p = 0.17) or sex (p = 0.44) between the LG enlarged and non-enlarged groups. There was also no significant difference in the clinical activity (p = 0.46) or prevalence of dysthyroid optic neuropathy (p = 0.63) between the LG enlarged orbits and non-LG enlarged orbits. Lacrimal gland enlargement may be observed in approximately thirty percent of TED patients, with asymmetric enlargement in approximately ten percent of cases.

Performance of an AI-powered visualization software platform for precision surgery in breast cancer patients.

Surgery remains the primary treatment modality in the management of early-stage invasive breast cancer. Artificial intelligence (AI)-powered visualization platforms offer the compelling potential to aid surgeons in evaluating the tumor's location and morphology within the breast and accordingly optimize their surgical approach. We sought to validate an AI platform that employs dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to render three-dimensional (3D) representations of the tumor and 5 additional chest tissues, offering clear visualizations as well as functionalities for quantifying tumor morphology, tumor-to-landmark structure distances, excision volumes, and approximate surgical margins. This retrospective study assessed the visualization platform's performance on 100 cases with ground-truth labels vetted by 2 breast-specialized radiologists. We assessed features including automatic AI-generated clinical metrics (e.g., tumor dimensions) as well as visualization tools including convex hulls at desired margins around the tumor to help visualize lumpectomy volume. The statistical performance of the platform's automated features was robust and within the range of inter-radiologist variability. These detailed 3D tumor and surrounding multi-tissue depictions offer both qualitative and quantitative comprehension of cancer topology and may aid in formulating an optimal surgical approach for breast cancer treatment. We further establish the framework for broader data integration into the platform to enhance precision cancer care.

Loss of aquaporin-4 impairs cerebrospinal fluid solute clearance through cerebrospinal fluid drainage pathways.

The aquaporin-4 (AQP4) water channel is essential in neurofluid dynamics. AQP4 loss impairs solute exchange between the cerebrospinal fluid (CSF) and interstitial fluid (ISF). However, whether AQP4 expression affects solute clearance from the CSF space to the extracranial space remains unclear. This study aimed to investigate this using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) following the intrathecal administration of gadolinium-based contrast agents (GBCAs) to AQP4 knockout (KO) rats. AQP4 KO rats showed reduced efflux of intrathecal GBCAs to the extracranial spaces through CSF drainage pathways and increased retention of intrathecal GBCAs in the CSF space compared with the controls. These results suggest that AQP4 loss impairs solute clearance from the CSF space to the extracranial spaces via the CSF drainage pathways. This study revealed a close relationship between AQP4 expression and CSF solute clearance, contributing to a better understanding of the function of AQP4 in neurofluid dynamics.

SURGICAL RESECTION OF A COMPLEX TUBERCULUM SELLAE MENINGIOMA ENCASING MAJOR ARTERIES

Introduction Though constituting only a minor proportion (1%) of sellar masses, suprasellar meningiomas pose a significant diagnostic challenge within the region of sellar and suprasellar tumors. Pituitary adenomas, at nearly 90% prevalence, dominate this anatomical region. Distinguishing these two entities is paramount, as both clinical presentation and, to some extent, biochemical profiles exhibit notable overlap. Accurate preoperative differentiation is critical due to the contrasting behaviors of these tumors. Meningiomas, with their robust vascularity supplied by dural and osseous arteries, present a heightened risk of intraoperative hemorrhage. Clinical Case A 53-year-old woman presented with a two-month history of worsening headaches and gradual vision loss. Neurological examination revealed only visual acuity decline. Her hormone profile showed elevated prolactin but lacked clinical features of prolactin excess, suggesting a possible prolactin-secreting pituitary macroadenoma. A contrast-enhanced MRI confirmed a significant sellar and suprasellar mass with homogeneous enhancement, extending to the right paramedian region and encasing the right internal carotid artery (ICA) at its critical segment involving the cavernous and supraclinoid portions. Furthermore, the right middle meningeal artery (M1) and anterior cerebral artery (A1) originated from this same location, highlighting the high surgical risk. Surgical resection was deemed necessary. The patient underwent a right pterional craniotomy, revealing a grayish, extradural soft mass lesion encasing the ICA bifurcation. Careful microsurgical dissection with basal devascularization was performed, followed by near-complete tumor removal using an ultrasonic aspirator to minimize damage to the encased arteries. Postoperative follow-up CT scan confirmed successful near-total tumor ablation. Conclusion This case underscores the critical role of meticulous preoperative diagnosis in managing complex sellar tumors. While pituitary adenomas dominate this region, suprasellar meningiomas, despite their rarity, demand a high index of suspicion. Overlapping clinical and biochemical presentations highlight the reliance on advanced imaging for accurate differentiation. The intricate vascularity of meningiomas, as exemplified by the encasement of critical arteries in this case, necessitates meticulous surgical technique with devascularization strategies. This successful near-complete tumor removal emphasizes the importance of such surgical expertise in navigating these diagnostically challenging sellar lesions.

Added-value of dynamic contrast-enhanced MRI to conventional MRI for the differentiation between inflammatory myofibroblastic tumor and squamous cell carcinoma in the sinonasal region.

The purpose of this study was to evaluate the additional value of dynamic contrast-enhanced (DCE) MRI and diffusion weighted MRI (DWI) in differentiation between inflammatory myofibroblastic tumor (IMT) and squamous cell carcinoma (SCC) in the sinonasal cavity. Patients with pathologically proven IMT and SCC in the sinonasal region were enrolled in this retrospective study. All participants underwent conventional MRI and dynamic contrast-enhanced MRI, while a subset of them performed DWI. All the MRI parameters were independently analyzed by two investigators. This retrospective study included 21 patients with IMT and 55 patients with SCC. Significant differences were found in the conventional MR imaging features including mass margin, T2 signal intensity and track sign of maxillary (p < 0.05). For DCE-MRI features, significant differences were found in progressive centripetal continual enhancement and CImax (p < 0.001 and p = 0.026, respectively). A marginal significant difference was found in ADC values between IMT (0.86 ± 0.59) and SCC (1.14 ± 0.25) (p = 0.061). The conventional MRI analysis revealed that the combination of mass margin and track sign of maxillary yielded an accuracy of 81.6%. Using a combination of progressive centripetal continual enhancement on DCE-MRI and track sign of maxillary in multivariate logistic regression analysis, the accuracy was elevated to 92.1%. The incorporation of DCE-MRI features into conventional MRI showed improved diagnostic performance in differentiating IMT from SCC in the sinonasal region. The novel progressive centripetal continual enhancement on DCE-MRI is the most effective feature of IMT.

The capabilities of cardiac MRI in the differential diagnosis of AL- and ATTR-amyloid cardiomyopathy.

BACKGROUND. Cardiac amyloidosis is a serious progressive disease with a high mortality rate. Differentiation between AL and ATTR types of amyloidosis is critically important for choosing the optimal treatment. AIM. This study aims to evaluate the capabilities of cardiac MRI in the differential diagnosis of AL and ATTR amyloidosis. METHODS. A retrospective analysis of medical data from 25 patients with confirmed cardiac amyloidosis (12 with AL and 13 with ATTR) was conducted. These patients underwent contrast-enhanced cardiac MRI, and their structural parameters (particularly wall thickness and myocardial mass), ventricular function, and late gadolinium enhancement (LGE) patterns were assessed. Standard statistical methods were used, with p-values 0.05 considered significant. RESULTS. Patients with ATTR amyloidosis exhibited more pronounced myocardial wall thickening (LV septal wall 17.8±2.3 mm vs 13.8±2.4 mm, p0.01; LV posterior wall 14.2±2.4 mm vs 10.8±2.0 mm, p0.01) and greater LV myocardial mass (110±30 vs 83±17 g/m², p0.01) compared to those with AL amyloidosis. In ATTR amyloidosis, transmural LGE was more frequently observed in the basal and mid inferior-lateral segments of the left ventricle, while subendocardial LGE was more common in the mid anterior and inferior-lateral segments (p0.05). A distinguishing feature of ATTR was the simultaneous contrast uptake in subendocardial layers of both the LV and RV in the area of the interventricular septum (100% vs 50%, p0.01). RV LGE was more common in ATTR (100% vs 58%, p0.05), particularly in the interventricular septum and the inferior wall of the RV (p0.05). Quantitative assessment of LGE using the QALE scale showed more extensive enhancement in ATTR (13 [12;14] vs 10.5 [1.75;12], p0.01). A score of more than 13 allowed differentiation between the types of amyloidosis with a sensitivity of 69% and specificity of 83%. CONCLUSION. Cardiac MRI can identify characteristic differences between AL and ATTR amyloidosis, which may assist in their differential diagnosis. Further research is needed to confirm the diagnostic accuracy of the identified MRI features.

Biomass-Derived Organonanomaterials as Contrast Agents for Efficient Magnetic Resonance Imaging.

Magnetic resonance imaging (MRI) is a popular imaging tool that is valuable for the early detection and monitoring of malignancies because it does not involve radiation and is noninvasive. Metal-based contrast agents (CAs) are commonly used in clinical settings despite concerns about the toxicity of free metals. Therefore, finding alternative nontoxic imaging probes is vital. In this work, we have synthesized and effectively utilized sustainable biomass lignin-based all-organic nanoconjugates linked with nitroxide radicals as MRI CAs. Lignin grafted with poly(4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl) (LPGT) exhibits a longitudinal relaxivity of 0.54 mM-1 s-1. LPGT shows exceptional characteristics, including resistance to reduction and nontoxicity toward living organisms. LPGT displays enhanced MRI contrast in the BALB/c mouse model for a duration exceeding 4.35 h. Our primary goal is to design MRI agents that are exceptionally effective sustainable biomass-derived materials and do not require the use of metals. Nicely, LPGT offers adequate contrast enhancement at 5-fold lower (0.020 mmol/kg) than the standard dose (0.1 mmol/kg), easing worries about toxic metal buildup. Consequently, LPGT shows promise as a feasible CA for metal-free MRI.

Abstract 4137891: Treated HIV infection is not associated with carotid vascular inflammation or plaque progression as assessed by dynamic contrast magnetic resonance imaging

Background: Inflammation and immune dysregulation are thought to drive residual cardiovascular disease risk among persons living with HIV (PLWH) despite effective viral suppression with antiretroviral therapy (ART). Question: We investigated differences in carotid vascular inflammation and atherosclerosis in a longitudinal cohort of virally suppressed PLWH (n = 50; on stable ART with CD4 &gt;250 cells/mm 3 , viral load &lt;200 copies/mL for &gt;6 months) and HIV-uninfected controls (n = 51) matched for age, sex, hypertension, diabetes, smoking, hyperlipidemia, and family history of premature coronary artery disease. Methods&amp;Results: Participants were &gt; 40 years old at enrollment, 8% female, and had a high prevalence of cardiovascular risk factors ( Table 1 ). Measures of carotid inflammation and capillary permeability ( K trans ), neovascularization ( V p ), and wall thickness were assessed at baseline, 1 year, and change over 1 year by dynamic contrast-enhanced magnetic resonance imaging. Both PLWH and controls demonstrated a reduction in systolic and diastolic blood pressures and total cholesterol over 1 year; however, the difference was not significant by HIV status. PLWH had a significant reduction in triglycerides compared with controls (-48.8 mg/dL vs 12.8 mg/dL; p = 0.026). HIV was not associated with baseline, follow-up, or change in markers of systemic inflammation assessed by plasma cytokines (C-reactive protein, interleukin-6, interleukin-1ß), nor vascular inflammation or plaque as assessed by K trans , V p , carotid wall thickness, or percent wall volume ( Tables 2 &amp; 3 ). Conclusions: In contrast to other studies of chronically treated and virally suppressed PLWH, HIV infection was not associated with carotid inflammation or plaque.

NCMP-29. BRAIN LESIONS IN A TEEN WITH NEWLY DIAGNOSED T-CELL ALL AND SARS-COV-2 INFECTION

Abstract T-cell Lymphoblastic Leukemia (T-cell ALL) accounts for up to 15% of all newly diagnosed cases of acute lymphoblastic leukemia in pediatric patients (0-18 years old). Patients are at risk of opportunistic infections during induction therapy with up to 2% developing blood stream infections when their absolute neutrophil count is above 1,500. We report a case of a 15-year-old female with High-Risk T-cell ALL, CNS1 (negative CNS disease), presenting with three days of headaches, photophobia, and non-neutropenic fever. She completed induction chemotherapy one week earlier with vincristine, daunorubicin, calaspargase and a 28-day course of dexamethasone. On physical exam, she had no focal deficits or changes in sensation or strength. CBC was notable for a white blood cell count: 7500, hemoglobin: 8.6, platelets: 328,000 and ANC (Absolute Neutrophil Count): 4700. The patient was also COVID positive on admission. A contrast enhanced MRI brain demonstrated multiple diffusion restricting and peripherally enhancing lesions, concerning for intracranial abscesses. Neurosurgery performed a burr hole craniotomy and aspirated 5 mL of purulent drainage, the culture of which grew Aspergillus fumigatus complex. The patient was started empirically on Voriconazole, in addition to broad spectrum antibiotic coverage pending culture results, due to excellent CNS penetration and proven superiority to amphotericin-based therapy for invasive aspergillosis. Micafungin was added due to CT chest demonstrating nodular infiltrates, suggesting primary pulmonary aspergillosis with CNS dissemination. The patient improved symptomatically without further sequelae. Patients with COVID-19 on prolonged courses of corticosteroids are at higher risk of developing fungal co-infections regardless of neutrophil count. While pulmonary aspergillosis is the most common location of a COVID-19 aspergillus coinfection, there have been documented reports of intracranial micro-abscesses. Contrast-enhanced brain MRI should be obtained in any patient with a recent history of COVID-19 presenting with new neurological symptoms, especially in a patient with a recent history of corticosteroids.

NIMG-24. PRECISION GLIOBLASTOMA MANAGEMENT USING MET AND FMISO PET SCANS

Abstract OBJECTIVE Positron Emission Tomography (PET) may be useful in diagnosing glioblastoma, determining resection areas, and evaluating therapeutic efficacy. This study evaluated the usefulness of PET scans using 11C-Methionine (MET) to assess amino acid metabolism and 18F-Fluoromisonidazole (FMISO) to assess hypoxic regions in glioblastoma treatment. METHODS Thirty glioblastoma patients who underwent MET and FMISO PET studies from July 2013 to March 2024 were included. Patients underwent the Stupp regimen post-tumor resection and were treated with temozolomide (TMZ) and bevacizumab (Bev) upon recurrence. PET scans were performed before and after two courses of Bev treatment. Changes in tumor to normal ratio (TNR) for MET, tumor to blood ratio (TBR) for FMISO, and metabolic tumor volume (MTV) for both MET and FMISO were evaluated. Progression-free survival (PFS) and overall survival (OS) were compared based on the rate of change in MTV for MET and FMISO. RESULTS The residual volumes (contrast-enhanced MRI, MET, and FMISO) with a MET removal rate of &amp;gt;90% were 0.08 ml, 0.1 ml, and 0.08 ml, respectively. For FMISO removal rates of &amp;gt;90%, residual volumes were 0.36 ml, 1.54 ml, and 0.05 ml, respectively. Groups with a decreased rate of change in MET MTV had significantly better outcomes: PFS (months) 10.7 vs. 2.8 (p=0.19) and OS (months) 18.6 vs. 4.9 (p=0.09). In the FMISO groups, decreased TBR change rates correlated with better outcomes: PFS (months) 16.6 vs. 2.5 (p&amp;lt;0.01) and OS (months) 22.8 vs. 4.9 (p&amp;lt;0.01). MTV change rates also showed significant differences in outcomes: PFS (months) 10.5 vs. 3.7 (p=0.76) and OS (months) 14.9 vs. 7.0 (p=0.87). CONCLUSION Higher MET removal rates correlate with fewer contrast-enhanced MRI and FMISO accumulation areas, suggesting MET as a reliable tumor removal indicator. Both MET and FMISO PET scans are valuable in determining glioblastoma treatment response.

NIMG-80. IMPACT OF KETOGENIC DIET ON MOLECULAR METABOLIC IMAGING WITH [18F]FDG AND [18F]DASA-23 POSITRON EMISSION TOMOGRAPHY IN A PATIENT WITH GLIOBLASTOMA

Abstract The standard-of-care for neuroimaging in patients with glioblastoma is contrast-enhanced MRI, which does not provide tumor metabolism information. Although [18F]FDG PET is used to image tumor metabolism in many solid organ cancers, it has limited benefit in atients with brain tumors due to the high level of glucose uptake in normal brain cells. [18F]DASA-23 is a novel PET radiotracer that assesses the levels of pyruvate kinase M2 (PKM2), a protein highly expressed in cancer cells, which undergo aberrant glycolysis. Despite [18F]DASA-23 having a higher tumor-to-background ratio (TBR) of standardized uptake values (SUVs) in the brain compared to [18F]FDG, both may be susceptible to altered carbohydrate metabolism in the setting of a ketogenic diet (KD). We report the case of a patient with glioblastoma on a KD, whose [18F]FDG and [18F]DASA-23 PET brain scans were limited in identifying disease progression (PD). Background was defined as the white matter contralateral to the tumor, at the level of the centrum semiovale, for TBR of SUVmax. A 39-year-old man was diagnosed with right temporal glioblastoma after previous diagnoses of grade 2 gliofibrillary oligodendroglioma (age 20) and grade 3 anaplastic oligodendroglioma (age 22). He began a KD after the glioblastoma diagnosis. 21 months later, TBR on [18F]DASA-23 PET was 1.38. One month later, surveillance brain MRI showed PD. Ten days later, TBR on [18F]FDG PET was 1.03. The patient died 15 months later. Despite MRI-based PD, the TBR of each radiotracer was not markedly elevated, although the [18F]DASA-23 TBR 1-month pre-PD was 34% greater than the [18F]FDG PET TBR 10-days post-PD. This may suggest a limitation of metabolic imaging by PET in the setting of a KD, and provide an opportunity to develop novel PET radiotracers that are not susceptible to the patient’s diet.

NIMG-26. GLIOBLASTOMA TISSUE INVASION MAPPING WITH NOVEL HYPOXIA-TARGETED BLOOD OXYGENATION-LEVEL DEPENDENT MRI

Abstract BACKGROUND Glioblastoma is a devastating incurable malignant primary brain tumor exhibiting an erratic growth pattern and brain tissue invasion exceeding the typically depicted contrast-enhancing lesion on MRI. This behaviour is strongly associated with the presence of aberrant vasculature. Advanced clinical neuroimaging techniques, however, have not provided convincing imaging markers to determine glioblastoma tissue infiltration and monitor treatment effects. We investigated a new imaging technique based on blood oxygenation-level dependent (BOLD) MRI contrast with precise hypoxic respiratory targeting in order to better determine tumor tissue invasion not restricted to the typically depicted focal glioblastoma lesion on contrast-enhanced MRI. METHODS A computer-controlled gas blender was used to induce transient and standardized hypoxic stimulus in isocapnic conditions during echo-planar-imaging acquisition in patients with brain tumors.8,9 Data were preprocessed using SPM and in-house written MATLAB scripts. The induced BOLD signal changes were used to calculate %BOLD signal change during hypoxic stimulus with respect to the baseline, contrast to noise (CNR) ratio and goodness-of-fit (Rsquared) for each voxel in the whole-brain and automatically segmented region of interest (contrast-enhancement, necrosis, edema) and overlayed using color-maps onto anatomical high resolution T1. RESULTS Hypoxic targeting during gas modulation could be performed with high reproducibility, caused no discomfort in patients with brain tumors and was able to induce strong signal change during hypoxic stimulus with high contrast-noise ratio and Rsquared. In particular, when compared with other tumors, BOLD hypoxia glioblastoma tissue invasion maps show very distinct hypoxic signal responses in some cases extending beyond the focal -contrast-enhancing- glioblastoma lesion. CONCLUSION The ability to map at voxel level BOLD hypoxia signal patterns may determine a novel therapeutic imaging marker based on structural vascular alterations in the tumour tissue infiltration zone before these become appreciable with standard neuroimaging. This may support a refinement and tailoring of tumor resection and improve follow-up after resection and during treatment i.e. chemoradiotherapy.

EPID-09. THE NATURAL HISTORY AND MOLECULAR ARCHITECTURE OF INCIDENTAL MENINGIOMAS

Abstract The prevalence of asymptomatic, incidental meningiomas is increasing due to greater frequency of brain imaging. This retrospective cohort study of adult patients presenting at a single institution from 1996-2020 integrated clinical data, serial magnetic resonance imaging (MRI) volumetrics, DNA methylation profiling, and targeted gene expression profiling to define the natural history and molecular architecture of incidental meningiomas. Volumetrics were calculated from contrast-enhanced brain MRIs at time of diagnosis compared to serial surveillance MRIs (average 3 MRIs per patient pre-intervention, range: 1-12) DNA methylation groups and gene expression risk scores were defined for 123 samples that underwent resection. Time-to-event analyses were performed for progression-free survival (PFS), symptom-free survival (SFS), and treatment-free survival (TFS). The cohort included 238 meningiomas from 207 patients. Median age at diagnosis was 59 years and 81.5% of patients were female. Median clinical and imaging follow-up were 9.1 and 6.7 years, respectively, during which time 50.8% progressed. Median maximum diameter and volume at diagnosis were 2.20 cm and 4.25 cm3, respectively, and median pre-treatment volumetric growth rate was 19.2% per year. Median pre-treatment PFS and TFS were 3.10 and 1.27 years, respectively, and median SFS and post-treatment PFS were not reached. Cox proportional hazards regression identified maximum diameter at diagnosis as a significant predictor of worse pre-treatment PFS (multivariate HR 1.65 per 1 cm [95% CI 1.19–2.28], p=0.0027) and worse TFS (multivariate HR 1.44 per 1 cm [95% CI 1.17–1.76], p&amp;lt;0.001). Skull base tumors had with worse SFS (multivariate HR 2.48 [95% CI 1.02–6.00], p=0.045). Molecular and histological features among incidental meningiomas that ultimately underwent resection (n=176, 74.0%) were reassuring (89.2% WHO grade 1, 10.2% WHO grade 2). These findings suggest maximum diameter at diagnosis of incidental meningiomas is significantly associated with earlier progression and eventual treatment, and skull base tumors have earlier symptom development.

Predicting malignancy in breast lesions: enhancing accuracy with fine-tuned convolutional neural network models.

This study aims to explore the accuracy of Convolutional Neural Network (CNN) models in predicting malignancy in Dynamic Contrast-Enhanced Breast Magnetic Resonance Imaging (DCE-BMRI). A total of 273 benign lesions (benign group) and 274 malignant lesions (malignant group) were collected and randomly divided into a training set (246 benign and 245 malignant lesions) and a testing set (28 benign and 28 malignant lesions) in a 9:1 ratio. An additional 53 lesions from 53 patients were designated as the validation set. Five models-VGG16, VGG19, DenseNet201, ResNet50, and MobileNetV2-were evaluated. Model performance was assessed using accuracy (Ac) in the training and testing sets, and precision (Pr), recall (Rc), F1 score (F1), and area under the receiver operating characteristic curve (AUC) in the validation set. The accuracy of VGG19 on the test set (0.96) is higher than that of VGG16 (0.91), DenseNet201 (0.91), ResNet50 (0.67), and MobileNetV2 (0.88). For the validation set, VGG19 achieved higher performance metrics (Pr 0.75, Rc 0.76, F1 0.73, AUC 0.76) compared to the other models, specifically VGG16 (Pr 0.73, Rc 0.75, F1 0.70, AUC 0.73), DenseNet201 (Pr 0.71, Rc 0.74, F1 0.69, AUC 0.71), ResNet50 (Pr 0.65, Rc 0.68, F1 0.60, AUC 0.65), and MobileNetV2 (Pr 0.73, Rc 0.75, F1 0.71, AUC 0.73). S4 model achieved higher performance metrics (Pr 0.89, Rc 0.88, F1 0.87, AUC 0.89) compared to the other four fine-tuned models, specifically S1 (Pr 0.75, Rc 0.76, F1 0.74, AUC 0.75), S2 (Pr 0.77, Rc 0.79, F1 0.75, AUC 0.77), S3 (Pr 0.76, Rc 0.76, F1 0.73, AUC 0.75), and S5 (Pr 0.77, Rc 0.79, F1 0.75, AUC 0.77). Additionally, S4 model showed the lowest loss value in the testing set. Notably, the AUC of S4 for BI-RADS 3 was 0.90 and for BI-RADS 4 was 0.86, both significantly higher than the 0.65 AUC for BI-RADS 5. The S4 model we propose has demonstrated superior performance in predicting the likelihood of malignancy in DCE-BMRI, making it a promising candidate for clinical application in patients with breast diseases. However, further validation is essential, highlighting the need for additional data to confirm its efficacy.