Citations

Background: Assessing craniocervical fibromuscular dysplasia (cc-FMD) can be challenging using cross-sectional imaging. We hypothesize that photon-counting detector CT (PCD-CT), owing to its superior spatial resolution over conventional energy-integrating detector CT (EID-CT), may better help appreciate changes in cc-FMD. Materials and Methods: In this retrospective cohort, 24 patients with radiologically reported cc-FMD (mean age: 54 y; 75% women) underwent both PCD-CT and EID-CT within 180 days (median: 52 d). Bilateral internal carotid (ICA) and vertebral artery (VA) segments without dissection/occlusion were graded on a 3-point scale (absent/likely present/present). Intermodality agreement was evaluated with weighted Cohen κ, and radiation dose metrics (CTDIvol) were compared using the paired Wilcoxon signed-rank tests. Results: Eighty-seven paired segments were analyzed. PCD-CT detected FMD in 48 segments (55.1%) versus 30 (34.5%) on EID-CT. The mean reader confidence scores were consistently higher with PCD-CT compared with EID-CT, for both ICAs (2.16±0.95 vs. 1.93±0.99) and VAs (1.86±0.95 vs. 1.36±0.75). Intermodality agreement was almost perfect for ICAs (κ=0.807) and substantial for VAs (κ=0.662). Under our institutional protocols, median CTDIvol was lower with PCD-CT (16.6 mGy) than EID-CT (21.5 mGy; P =0.0112). Conclusion: PCD-CT demonstrated more frequent reader categorization of cc-FMD features than EID-CT, particularly in the VAs, and had a lower median CTDIvol under our institutional protocols. These preliminary findings suggest improved cc-FMD detection with PCD-CT as compared with EID-CT and require prospective, reference-standard validation to establish accuracy and clinical impact.

Abstract BACKGROUND MYCN-amplified spinal ependymoma is a recently classified, rare, and aggressive subtype of spinal cord tumor, first defined by the 2021 WHO CNS5 classification. It predominantly affects adults in their 30s, with a slight female predominance; fewer than 50 cases have been reported worldwide. PURPOSE To characterize the molecular, imaging, and clinical features of MYCN-amplified spinal ependymomas and highlight their distinctiveness to aid in early diagnosis and therapeutic planning. METHODS We retrospectively reviewed institutional cases of MYCN-amplified spinal ependymomas and performed a literature-based analysis. Data on imaging, histopathology, molecular profiles, and clinical outcomes were examined to identify distinguishing diagnostic and prognostic features. RESULTS These tumors are typically present as intradural extramedullary masses, often in the thoracic spine, with intense contrast enhancement and prominent peritumoral edema. A lack of a clear cleavage plane with the spinal cord, early leptomeningeal, and intracranial dissemination are hallmark features. Rare reports of systemic metastases (e.g., to the humerus and paraspinal muscle) exist. Histologically, they are high-grade (WHO grade III) anaplastic ependymomas with a distinct DNA methylation profile. MYCN amplification—commonly seen in medulloblastomas and glioblastomas—drives tumor aggressiveness. Clinically, these tumors are refractory to standard treatments, with high rates of recurrence or progression within 1–2 years post-treatment. The median overall survival is approximately seven years, significantly poorer than conventional spinal ependymomas. CONCLUSION MYCN-amplified spinal ependymomas represent a rare but highly aggressive tumor subtype with unique imaging, histological, and molecular features. Early recognition is critical given rapid progression and poor prognosis. Investigational therapies targeting MYCN—such as HDAC, PARP, Aurora A-kinase, and BET inhibitors—hold promise for improved outcomes.

Objective: Vestibular schwannomas (VSs) treated with stereotactic radiosurgery (SRS) often show transient loss of central tumor enhancement. We hypothesized that this loss of enhancement may correlate with better tumor control on follow-up imaging. Methods: We evaluated 198 consecutive patients from a single center who met eligibility criteria. Tumor volumes on the pre-SRS and post-SRS scans were quantified along with regions of loss of enhancement on the first post-SRS study. The latter was correlated with tumor volumes at follow-up, radiation isocenter density, and loss of serviceable hearing. Results: For the entire cohort, the median loss of enhancement on the first post-SRS scan was 14% (IQR: 6 to 25) and median rate of change in tumor volume was −4.5% per year (IQR: −10.5 to 1.5). Percent loss of central enhancement showed significant negative correlation with tumor growth not only for the entire cohort (correlation coefficient: −0.18, P =0.01), but also for the subset of patients who had available imaging until at least 2 years (n=185) and 4 years (n=179) post-SRS. Loss of enhancement also strongly correlated positively with tumor volumes and number of radiation isocenters and negatively with isocenter density. Finally, patients with greater percent loss of enhancement had an increased likelihood of progression to non-serviceable hearing, although this association was not statistically significant. Conclusions: These findings suggest that loss of central tumor enhancement in VSs post-SRS may be associated with improved tumor control.

Despite their similar nomenclature, Neurofibromatosis type 1 (NF1) and “Neurofibromatosis type 2” are discrete and clinically distinguishable entities. The name of “neurofibromatosis type 2” has been changed to NF2-related schwannomatosis, to reflect the fact that neurofibromas do not occur in this syndrome and therefore the name “Neurofibromatosis” is factually incorrect. Furthermore, multiple schwannomas, a hallmark feature of NF2, can also occur in patients with mutations in genes including SMARCB1 and LZTR1, all exhibiting overlapping clinical features. Current understanding suggests that schwannomatosis (SWN) encompasses a range of clinical presentations consisting of clearly defined, separate subtypes which share a common phenotype of schwannomas. Recognizing these newly emerging subtypes, the International Consensus Group on Neurofibromatosis Diagnostic Criteria (I-NF-DC) proposed a revised nomenclature for NF2 and related disorders in 2022. This review article focuses on this critical update in diagnostic terminology, highlighting the key gene-related SWN subtypes relevant to neuroradiologists. By emphasizing molecular testing alongside clinical features, the revised system facilitates a more precise diagnosis, potentially paving the way for personalized treatment strategies. Additionally, the flexible structure accommodates future discoveries of genes associated with SWN.

AbstractVascularity plays a pivotal role in the progression of breast lesions and may be associated with their aggressiveness and likelihood of being malignant. Contrast-enhanced imaging techniques are necessary to evaluate vascularity due to the limited sensitivity of conventional color Doppler techniques, in which motion artifacts are eliminated using wall filters. However, in this process, low-flow signals from small vessels also get removed unintentionally. Advancements in technology have revolutionized the way ultrasound images are generated, resulting in tremendous improvements in Doppler imaging techniques. The new, ultrasound-based noncontrast microvascular imaging techniques overcome the limitations of conventional Doppler, and are highly sensitive for detecting microvessels and low flow. The resultant high Doppler sensitivity leads to detection of vascularity in more breast lesions. It is important for radiologists to understand the imaging principles and the clinical implications of the new techniques, to optimally utilize them and aid correct diagnosis. Angio-PLUS is one such recent advancement, which uses unfocused or plane waves and three-dimensional wall filtering to analyze tissue motion in time, space, and amplitude domains that effectively distinguish between blood flow and tissue. The information is beneficial for assessing the lesion vascularity without using contrast. This article aims to explain the Doppler imaging techniques, their clinical applications, scanning methods, and review the common Doppler-based diagnostic criteria used in the evaluation of breast lesions.

Cauda Equina Neuroendocrine Tumors (CE-NET), previously referred to as paragangliomas are a rare subset of spinal tumors, with limited data on imaging. Herein, we present a retrospective review of clinical and imaging findings of CE-NETs in ten patients who were evaluated at our institution over the past two decades. All patients had well-defined intradural lesions in the lumbar spine which demonstrated slow growth. A review of imaging findings revealed the presence of an eccentric vascular pedicle along the dorsal aspect of the tumor in 8 of the 10 patients (eccentric vessel sign), a distinctive finding that has not previously been reported with this tumor and may help improve the accuracy of imaging-based diagnosis. In all cases, a gross-total resection was performed, with resolution of symptoms in most of the cases.

Introduction Survival prediction in glioblastoma remains challenging, and identification of robust imaging markers could help with this relevant clinical problem. We evaluated multiparametric magnetic resonance imaging–derived radiomics to assess prediction of overall survival (OS) and progression-free survival (PFS). Methodology A retrospective, institutional review board–approved study was performed. There were 93 eligible patients, of which 55 underwent gross tumor resection and chemoradiation (GTR-CR). Overall survival and PFS were assessed in the entire cohort and the GTR-CR cohort using multiple machine learning pipelines. A model based on multiple clinical variables was also developed. Survival prediction was assessed using the radiomics-only, clinical-only, and the radiomics and clinical combined models. Results For all patients combined, the clinical feature–derived model outperformed the best radiomics model for both OS (C-index, 0.706 vs 0.597; P < 0.0001) and PFS prediction (C-index, 0.675 vs 0.588; P < 0.001). Within the GTR-CR cohort, the radiomics model showed nonstatistically improved performance over the clinical model for predicting OS (C-index, 0.638 vs 0.588; P = 0.4). However, the radiomics model outperformed the clinical feature model for predicting PFS in GTR-CR cohort (C-index, 0.641 vs 0.550; P = 0.004). Combined clinical and radiomics model did not yield superior prediction when compared with the best model in each case. Conclusions When considering all patients, regardless of therapy, the radiomics-derived prediction of OS and PFS is inferior to that from a model derived from clinical features alone. However, in patients with GTR-CR, radiomics-only model outperforms clinical feature–derived model for predicting PFS.