Clinical Neuroradiology最新文献

Purpose: Assess the prevalence of thalamic AVM (tAVMs), their revealing conditions and angio-architectural features, as well as their therapeutic management.

Methods: Monocentric retrospective study (1998 to 2018) involving 748 consecutive patients with a brain AVM managed at the Pitié-Salpêtrière Hospital, from which tAVMs were retrieved. Revealing condition of the tAVMs was recorded. tAVMs' angio-architecture was systematically reviewed on angiographic examinations. The safety and effectiveness of treatments (conservative management and exclusion treatment) were evaluated based on clinical and angiographic criteria.

Results: Twenty-two consecutive patients (9 males, mean age: 32 ± 14 years) with a tAVM were included (prevalence: 2.9%). tAVMs were revealed by a bleeding event in 86.4% of cases. The posterolateral choroidal artery was the most frequently observed arterial feeder in our series (71.4%). Associated aneurysm (nidal and/or pedicular) was observed in 36.4% of patients. The tAVMs' mean volume was 6.45 ± 12.8 ml. Venous drainage was in the deep venous system only in most cases (81%). Four patients received conservative management, 12 patients were treated by radiosurgery and 12 by embolization, with 6 patients (27.2%) who received both embolization and radiosurgery. Complete nidal occlusion was achieved in 33.3% of the patients who underwent angiographic follow-up. Two embolized patients (16.7%) suffered severe embolization-related complications, and 4 patients treated with radiosurgery (33.3%) suffered severe procedure related complication, all of which resolved without significant sequela.

Conclusion: Our results underline the safety of exclusion treatments by embolization and/or radiosurgery of tAVMs. Efficacy in terms of angiographic exclusion still needs to be demonstrated at long-term due to limited imaging follow-up.

Background and purpose: Incomplete reperfusion in endovascular thrombectomy (EVT) impacts patients' outcomes. Different incomplete reperfusion patterns may benefit from targeted therapeutic strategies, e.g. EVT-accessible incomplete reperfusion patterns could improve by performing additional EVT attempts, while EVT-non-accessible incomplete patterns might benefit from pharmacological therapies. The health-economic implications of these therapies are uncertain. This study aims to assess the potential economic benefits of improving incomplete reperfusion patterns after EVT.

Materials and methods: Retrospective Data analysis from the ESCAPE-NA1 trial, which included patients with large vessel occlusion strokes undergoing EVT. Reperfusion patterns were classified as near-/complete (eTICI 2c3), EVT-accessible incomplete (eTICI 2b), or EVT-non-accessible incomplete (eTICI 2b) and we compared multiple attempts to achieve eTICI 2c3 vs. first-pass eTICI 2c3. A Markov-Model was built to compare lifetime costs and quality adjusted life-years (QALY) for each reperfusion pattern over a lifetime horizon, considering both healthcare and societal perspectives.

Results: A total of 1105 of patients were enrolled in the ESCAPE-NA1 trial of which 949 with eTICI 2b, 2c and 3 were further analyized (mean age 70.7 ± 13.6 [SD]; 463 female). Near-Complete reperfusion (eTICI 2c3) was achieved in 506/1105 patients (45.8%). Incomplete reperfusion patterns (eTICI 2b) were found in 450/1105 (40.7%) patients. Angiography imaging could be further investigated in 443/450 (98.4%) cases with 147/443(33.2%) EVT-accessible and 296/443(66.8%) EVT-non-accessible incomplete reperfusion patterns. Compared to EVT-accessible and EVT-non-accssible incomplete reperfusion, achieving complete (eTICI 2c3) reperfusion resulted in lower costs and an additional 1.14/0.45 QALYs, making it the dominant strategy from a health-economic perspective. In the complete reperfusion (eTICI 2c3) group, cumulative lifetime QALYs were similar with 5.25 for single-pass eTICI 2c3 and 5.19 for multi-pass eTICI 2c3.

Conclusions: Improving incomplete reperfusion patterns after EVT has considerable potential health economic benefits, both in the presence and absence of a target occlusion that is amenable to EVT.

Introduction/background: The rising demand for endovascular stroke therapy highlights the need for standardized training environments. Studies have shown the positive impact of simulator-based training for neurointerventional procedures. Given the frequent use of percutaneous transluminal angioplasty (PTA) of the internal carotid artery (ICA) in acute settings, specialized simulation training is crucial. This study evaluates the feasibility of a custom-made ICA stenosis model for PTA simulation.

Methods: Internally developed 3D-printed circular clamps were attached to patient-based 3D printed ICA models and integrated into a previously described realistic whole-body neurovascular simulation model HANNES (Hamburg Anatomic Neurointerventional Endovascular Simulator) to simulate a proximal ICA stenosis. Participants (N = 5) of varying experience levels each performed three PTA procedures. Fluoroscopy time, radiation doses, and the extent of stenosis and balloon inflation pressure were assessed. After simulation, participants rated the model in terms of haptic, feasibility and applicability.

Results: For statistical analysis, the participants were divided into two groups according to their experience level. There was a statistically significant difference in the procedure duration between both groups, U = 10.500, Z = -1.968, p < 0.05. Significant test results could also be demonstrated for radiation doses (DAP) among groups, Kolmogorov-Smirnov p < 0.05, U = 7.000, Z = -2.357, p < 0.05. No difference was shown between the total contrast volume (ml) among groups that was used during procedures (m = 11.67, SD 2.09).

Conclusion: The authors propose a novel ICA stenosis simulation model for training of the cervical PTA. The model provides a realistic and replicable method for standardized procedural training.

Background and purpose: Molecular glioblastomas are challenging to distinguish from lower-grade diffuse astrocytomas (grades 2-3) without T2/T2 FLAIR mismatch, when assessed on T1-gadolinium and T2/T2 FLAIR MRI. This study aimed to evaluate the performance of the ADC from diffusion-weighted imaging and the relative CBV from DSC perfusion imaging in differentiating molecular glioblastomas from lower-grade diffuse astrocytomas.

Materials and methods: Fourteen patients with molecular glioblastomas (defined as isocitrate dehydrogenase wildtype (IDH-wt), exhibiting one or more of the following: telomerase reverse transcriptase (TERT) promoter mutation, epidermal growth factor receptor (EGFR) gene amplification, or +7/-10 chromosomal alterations, but without microvascular proliferation or necrosis) and thirteen patients with lower-grade diffuse astrocytomas (IDH-mutated or not elsewhere classified, grades 2-3) were included. ADC values and DSC-rCBV values were measured, and the two groups were compared using T‑test and Wilcoxon rank-sum test. Combinations of variables and tumor characteristics were analyzed using binary logistic regression, receiver operating curve (ROC) analysis, and Firth regression model.

Results: Molecular glioblastomas exhibited lower minimum ADC, mean ADC (p < 0.01), maximum ADC (p < 0.05) and higher standard deviation of ADC (p < 0.05), compared to lower-grade astrocytomas, measured in a 7 mm² ROI in the lowest ADC region. Molecular glioblastoma also had higher normalized median, average, and minimum rCBV ratios (p < 0.01) in a 10 mm² ROI in the highest perfused region. A combined receiver operating curve (ROC) model of ADC and rCBV achieved an area under the curve (AUC) of 0.93 (95% CI: 0.82-1.00).

Conclusions: This study demonstrates that ADC and rCBV measurements can help differentiate molecular glioblastomas from lower-grade diffuse astrocytomas lacking T2/T2 FLAIR mismatch. These findings may aid in preoperative tumor characterization, surgical planning, and prognosis.

Purpose: The "no-reflow phenomenon" refers to persisting microvascular failure despite complete macrovascular reperfusion. We investigated whether parametric color coding (PCC) analysis of the DSA-series after successful mechanical thrombectomy could predict microvascular dysfunction.

Methods: We retrospectively analyzed the STAMINA database for patients admitted to a single tertiary care center over a 5-year period with MCA-Occlusion (M1 or M2 branch), large penumbra, TICI 3 and infarct volume exceeding 15 ml on follow-up CT-presumed to reflect microvascular failure. These 55 patients were compared to 55 controls with infarcts < 15 ml on follow-up CT. As proof of concept, we included 42 non-stroke patients undergoing elective treatment of unruptured intracranial aneurysms. Using iFlow-PCC software, we calculated critical flow parameters, including cerebral circulation time (CirT), relative cortical time to peak (rTTP), and microvascular transit time (mTT).

Results: Microvascular transit time (mTT) was significantly prolonged in the suspected microvascular failure group (3.22 ± 0.85 s) compared to the recanalization control group (2.79 ± 0.64 s; p = 0.003) and the non-stroke interventional control group (2.54 ± 0.90 s, p = 0.0003). The group with suspected microvascular failure exhibited a median modified Rankin Score at 3 months (mRS 3M: 4, IQR: 3-5) and a higher number of poor outcomes (mRS 5-6; n = 16) compared to the control group with similar strokes (median mRS 3M: 2, IQR: 1-4; mRS 5-6: n = 4).

Conclusion: Prolonged microvascular transit time (mTT) can predict microvascular failure after thrombectomy. Angiographic flow analysis, performed directly in the angio-suite allows early identification of patients who may benefit from additional therapy like intra-arterial thrombolysis.

Selection of appropriate imaging sequences protocols for cranial magnetic resonance imaging (MRI) is crucial to address the medical question and adequately support patient care. Inappropriate protocol selection can compromise diagnostic accuracy, extend scan duration, and increase the risk of misdiagnosis. Typically, radiologists determine scanning protocols based on their expertise, a process that can be time-consuming and subject to variability. Language models offer the potential to streamline this process. This study investigates the capability of bidirectional encoder representations from transformers (BERT)-based models to suggest appropriate MRI protocols based on referral information.A total of 410 anonymized electronic referrals for cranial MRI from a local order-entry system were categorized into nine protocol classes by an experienced neuroradiologist. A locally hosted instance of four different, pre-trained BERT-based classifiers (BERT, ModernBERT, GottBERT, and medBERT.de) were trained to classify protocols based on referral entries, including preliminary diagnoses, prior treatment history, and clinical questions. Each model was additionally fine-tuned for local language on a large dataset of electronic referrals.The model based on medBERT.de with local language fine-tuning was the best-performing model and correctly predicted 81% of all protocols, achieving a macro-F1 score of 0.71, macro-precision and macro-recall values of 0.73 and 0.71, respectively. Moreover, we were able to show that local language fine-tuning led to performance improvements across all models.These results demonstrate the potential of language models to predict MRI protocols, even with limited training data. This approach could accelerate and standardize radiological protocol selection, offering significant benefits for clinical workflows.

Background: Embolization of the middle meningeal artery (EMMA) is a promising novel technique for the treatment of patients with chronic subdural hematomas (cSDH).

Methods: After a nationwide query in Germany, patients with cSDH, treated with EMMA were retrospectively analyzed. Patient and cSDH characteristics, procedural parameters, complications, and rates of treatment failure (TF; residual cSDH > 10 mm, cSDH progression or requirement of rescue surgery) were investigated. TF rates were compared between first-time treatments and treatments of recurrent cSDH, patients receiving embolization and surgery and those being embolized only, different types of embolic agents (particles vs. liquid agents) and between patients with and without antithrombotic medication.

Results: 718 EMMAs (420 unilateral, 149 bilateral) were performed in 569 patients in 30 German neurovascular centers. 57.1% were first-time treatments and 42.9% were treatments of recurrent cSDHs. The most frequently used embolic agents were particles (56.2%), followed by copolymer-based liquid embolic agents (19.6%). The rate of symptomatic procedure-related complications was 2.5%. After a mean follow-up of 6.5 months, TF was observed in 16.2% across all treatments and was more frequent after the treatment of recurrent cSDHs (19.8% vs. 13.5%, p = 0.045) and in patients taking antithrombotic drugs (17.7% vs. 11.5%; p = 0.044). TF was not significantly different regarding the type of embolic agent or additional surgery.

Conclusions: In this nationwide multi-center study, EMMA was associated with favorable clinical outcomes and a low complication rate, supporting the results of recently published randomized controlled trials. TF was more frequent in recurrent cSDH treatments and in patients taking antithrombotic drugs.