AJNR. American journal of neuroradiology最新文献

Background and purpose: The NI-RADS scoring system standardized imaging surveillance of head and neck (H&N) cancer with risk classification. A nodal NIRADS score of 2 on contrast-enhanced CT (CECT) of the neck indicates low suspicion for recurrence/persistent disease and close follow-up or addition of PET are recommended. The unclear follow-up imaging findings and/or mild FDG uptake raise patient's anxiety of potential delay in diagnosis and intervention while adding high imaging cost. Therefore, at our institution, diagnostic US/US-guided fine needle aspiration (US-FNA) is incorporated in our paradigm. We aim to evaluate US performance in nodal NI-RADS 2 on CECT as alternative valuable tool in surveillance imaging guidelines.

Materials and methods: We conducted a retrospective database search (2019-2024) for patients with primary H&N cancer (excluding thyroid cancer and melanoma), a single index neck node NI-RADS 2 on surveillance CECT neck, and a neck US/US-FNA performed within 3 months afterwards for evaluation of the NI-RADS 2 node. We categorized US/US-guided FNA results as positive or negative and reviewed clinical and imaging follow-up, management and nodal disease status up to 1 year following US. The incidence of nodal recurrence and US diagnostic performance were evaluated.

Results: Of 90 patients, 36 (40%) had normal diagnostic US with no FNA performed and were thus considered negative, and 54 patients (60%) had abnormal US and hence concurrent US-FNA. 18 (33.3%) US-FNAs were positive for tumor; 27 with normal lymphoid tissue and 9 with indeterminate cytology (no viable malignant cells, acellular or atypia) were considered negative (66.7%). All positive US-FNAs resulted in management changes. 2 patients with normal diagnostic US, 1 with negative FNA and 1 with indeterminate FNA developed recurrence in these nodes within 1 year. The incidence of US-detected malignancy was 20% in patients with a nodal NIRADS 2, surpassing the published rate of 14.3%. The sensitivity, accuracy and NPV of US/US-FNA in detecting tumor recurrence/persistence in nodal NI-RADS 2 are 81.8%, 95.6% and 94.4% respectively.

Conclusions: Ultrasound demonstrated good diagnostic performance in the detection of nodal recurrence in patients with NI-RADS 2 on CECT. Its role as an alternative tool in surveillance should be considered.

Abbreviations: CECT = contrast-enhanced CT; CEMR = contrast-enhanced MR; ENE = extranodal extension; FNA = fine-needle aspiration; NI-RADS = Neck Imaging Reporting and Data System; NPV = negative predictive value; PPV = positive predictive value; SCC = squamous cell carcinoma; RVU = relative value units; US = ultrasound.

Background and purpose: The outcomes of prophylactic endovascular interventions for patients facing threatened or impending carotid blowout syndrome (CBS) involving the internal/common carotid artery (ICA/CCA) have not been extensively elucidated. We aimed to delineate the specific treatment outcomes for this group of patients.

Materials and methods: We retrospectively enrolled 109 patients with threatened or impending CBS of the ICA/CCA between 2006 and 2023. Patients were categorized into Group 1 (no intervention for ICA/CCA, n=43), Group 2 (ICA/CCA embolization, n=36), or Group 3 (ICA/CCA stenting, n=30). ANOVA and Cox regression analyses were employed to evaluate basic characteristics and the rates of recurrent bleeding, overall survival, and major complications.

Results: Age (56.8 ± 8.7 vs. 54.3 ± 11.6 vs. 56.6 ± 9.2), male sex (39/43 vs. 33/36 vs. 26/30), tumor size, and type of blowout were similar (P>0.05) among groups. Tumor location (P<0.001) and presence of air-containing necrosis on CT/MRI before trans-arterial embolization (P=0.001) varied between groups. Cox regression analysis adjusted for age and sex revealed Group 2 had a lower risk of recurrent bleeding than Group 1 (adjusted hazard ratio (HR), 0.22; 95% CI, 0.10-0.47; P<0.001) and Group 3 (0.41; 95% CI, 0.170.96; P=0.042), but a higher risk of acute stroke (P=0.016). Group 2 had higher overall survival than Groups 1 and 3 (0.55; 95% CI, 0.31-0.96; P=0.036).

Conclusions: In threatened or impending CBS of the ICA/CCA, prophylactic embolization was associated with a lower risk of recurrent bleeding but a higher risk of acute stroke compared to ICA/CCA stenting or no intervention.

Abbreviations: BTO = balloon test occlusion; CBS = carotid blowout syndrome; CCA = common carotid artery; ECA = external carotid artery; HR = hazard ratio; ICA = internal carotid artery; TAE = trans-arterial embolization.

Background and purpose: Anatomical imaging is a hallmark for visualizing chronic and acute infarcts but provides incomplete information on stroke risk. Respiratory hypercapnic gas challenges show promise for non-invasively assessing hemodynamic function and mapping cerebrovascular reserve capacity, an indicator of how near parenchyma is to exhausting autoregulatory capacity. However, limited safety information exists for this method in high-risk patients with flow-limiting stenosis. This study reports on the physiological changes and adverse events (AEs) following diagnostic hypercapnic cerebrovascular reactivity imaging assessments.

Materials and methods: Between January 2011 and May 2024, reactivity scans were performed on 262 patients. In patients with flow-limiting intracranial arterial steno-occlusion (>70%), vital signs were assessed during a twice-repeated three-minute fixed-inspired 5%CO2/95%O2 stimulus, and acute (0-24 hours), sub-acute (24 hours - 2 months), and longer-term (2 - 12 months) AEs were recorded.

Results: 129 patients met criteria for flow-limiting arterial steno-occlusion. Blood pressure did not change (p>0.40) with hypercapnia. EtCO₂ (baseline:36.5±4.5 mmHg, hypercapnia:42.5±3.8 mmHg) and SaO₂ (baseline:97.5±1.8%, hypercapnia:99.4±0.8%) increased (p<0.001), paralleling hypercapnic-hyperoxic physiology. No acute ischemic adverse events were noted. One sub-acute and four long-term neurological events were noted, within expected range for this population.

Conclusions: Findings support using hypercapnic reactivity mapping in the setting of flow-limiting cerebrovascular disease.

Abbreviations: CVR = cerebrovascular reactivity, MRI = magnetic resonance imaging, EtCO₂ = end-tidal carbon dioxide, SaO₂ = arterial oxygen saturation, BOLD = blood oxygenation level-dependent, AE = adverse event, SAE = serious adverse event.

Background and purpose: The Radiological Society of North America has actively promoted artificial intelligence (AI) challenges since 2017. Algorithms emerging from the recent RSNA 2022 Cervical Spine Fracture Detection Challenge demonstrated state-of-theart performance in the competition's dataset, surpassing results from prior publications. However, their performance in real-world clinical practice is not known. As an initial step towards the goal of assessing feasibility of these models in clinical practice, we conducted a generalizability test using one of the leading algorithms of the competition.

Materials and methods: The deep learning algorithm was selected due to its performance, portability and ease of use and installed locally. 100 examinations (50 consecutive cervical spine CT scans with at least one fracture present and 50 consecutive negative CT scans) from a Level 1 trauma center not represented in the competition dataset were processed at 6.4s per exam. Ground truth was established based on the radiology report with retrospective confirmation of positive fracture cases. Sensitivity, specificity, F1 score, and AUC were calculated.

Results: The external validation dataset was comprised of older patients in comparison to the competition set (53.5 ± 21.8 years vs 58 ± 22.0 respectively; p < .05). Sensitivity and specificity were 86% and 70% in the external validation group and 85% and 94% in the competition group, respectively. Fractures misclassified by the CNN frequently had features of advanced degenerative disease, subtle nondisplaced fractures not easily identified on the axial plane, and malalignment.

Conclusions: The model performed with a similar sensitivity on the test and external dataset, suggesting that such a tool could be potentially generalizable as a triage tool in the emergency setting. Discordant factors such as age-associated comorbidities may affect accuracy and specificity of AI models when used in certain populations. Further research should be encouraged to help elucidate the potential contributions and pitfalls of these algorithms in supporting clinical care.

Abbreviations: AI= artificial intelligence; CNN = convolutional neural networks; RSNA= Radiological Society of North America.

Background: Cerebral aneurysm recurrence serves as a significant endpoint for assessing the efficacy of various endovascular treatment strategies. The impact of smoking on outcomes such as aneurysm occlusion, recurrence, and recanalization remains unclear due to conflicting evidence.

Purpose: To systematically evaluate the role of smoking in influencing angiographic outcomes following endovascular treatment of intracranial aneurysms.

Data sources: Comprehensive searches were conducted in PubMed, Embase, Scopus, and Web of Science STUDY SELECTION: This systematic review and meta-analysis followed PRISMA guidelines to identify relevant studies assessing smoking's impact on intracranial aneurysms following endovascular treatment.

Data analysis: Studies were screened, selected, and assessed for risk of bias using appropriate checklists. Data on complete and adequate aneurysm occlusion, and recurrence/recanalization rates were extracted. Random-effects meta-analyses calculated risk ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was measured using the I² statistic.

Data synthesis: A total of 26 studies, encompassing 6,031 patients, met the inclusion criteria. Smokers had higher rates of complete aneurysm occlusion (RR 1.12, 95% CI 1.06-1.19; p < 0.01). Subgroup analysis revealed that smokers undergoing flow diversion exhibited a higher rate of complete occlusion (RR 1.14, 95% CI 1.07-1.21; p < 0.01). However, for patients undergoing coiling, there was no significant difference in complete occlusion rates between smokers and non-smokers (RR 1.00, 95% CI 0.83- 1.20; p = 0.46). Recurrence/recanalization rates were similar between smokers and non-smokers: RR 1.17, 95% CI 0.93-1.47; p = 0.20, and the rate of aneurysm retreatment did not differ between the smokers and non-smokers: RR 0.82, 95% CI 0.59-1.13; p =0.23.

Limitations: Heterogeneity in definitions of smoking status, variations in follow-up durations, short follow up, retrospective nature of studies.

Conclusions: Smoking status does not significantly impact aneurysm recanalization or retreatment after endovascular repair. However, the impact of smoking on complete occlusion rate might differ based on the type of device used for treatment. Histological and molecular factors may contribute to varied outcomes, highlighting the necessity for further research to understand smoking's role in aneurysm healing. Clinically, patients should be advised about the risks of smoking, though current evidence suggests that smoking cessation may not consistently affect treatment efficacy.

Abbreviations: sAH = subarachnoid hemorrhage; RROC = Raymond-Roy occlusion classification.

Background and purpose: Probabilistic brain MRI scoring systems have been introduced to stratify the likelihood of identifying a CSF leak at myelography in spontaneous intracranial hypotension (SIH). The Bern scoring system by Dobrocky et al. is now well recognized, with a scoring system by Benson et al. introduced more recently (referred to as the "Mayo" score in this study). Neither of these scoring systems have been thoroughly evaluated in patients without SIH. The goal of this study was to evaluate these scoring systems in patients without SIH to understand the specificity of these MRI findings.

Materials and methods: We retrospectively reviewed normal brain MRIs performed in patients without clinically suspected SIH. Each examination was reviewed by one of four board-certified neuroradiologists with extensive experience in SIH, and all criteria of both scoring systems were evaluated and recorded.

Results: 90 patients were included. Bern score was low probability in 78% and intermediate probability in 22%. Mayo score was low probability in 100%. Relatively high rates of positivity were seen in three specific Bern score parameters, including prepontine cistern effacement 5.0 mm or less (53%), decreased mammilopontine distance 6.5 mm or less (40%), and suprasellar cistern effacement 4.0 mm or less (28%). All intermediate probability Bern scores were due to suprasellar cistern effacement plus either or both prepontine cistern effacement and decreased mammilopontine distance. All other parameters of both scoring systems were either never or very rarely positive.

Conclusions: All intermediate probability Bern scores were due to decreased CSF cistern measurements, which had relatively high positivity rates in our non-SIH patient cohort. Due to substantial overlap with normals, these measurements are not specific indicators of "brain sag", a hallmark imaging finding for SIH, and are not specific for SIH when the only "positive" brain MRI finding(s). The Mayo score is likely more specific for SIH with low probability scores in all patients in our cohort.

Abbreviations: SIH, spontaneous intracranial hypotension; DSM, digital subtraction myelography; CTM, CT myelography; PC-CTM, photon counting CT myelography; CVF, CSF-venous fistula; ICC, intraclass correlation coefficient.

Background and purpose: Endovascular thrombectomy is a standard treatment for acute ischemic stroke due to large-vessel occlusions (AIS-LVO), but a large minority of patients do not achieve successful reperfusion. This study aimed to investigate the hypoperfusion intensity ratio (HIR) as a prognostic biomarker in unsuccessfully reperfused patients with AIS-LVO.

Materials and methods: A multicenter retrospective cohort study was conducted at 2 comprehensive stroke centers, involving patients with AIS-LVO who underwent endovascular thrombectomy but did not achieve successful reperfusion, defined as a modified TICI score of 0-2a. HIR, derived from CT or MR perfusion imaging, was analyzed for its association with favorable clinical outcomes (90-day mRs score of 0-2). The optimal HIR threshold predictive of favorable outcomes was identified through receiver operating curve analysis.

Results: Of 129 patients included, 20 (15.5%) achieved favorable outcomes. HIR of <0.4 significantly predicted favorable outcomes with a sensitivity of 66% and specificity of 80%. Patients with an HIR of <0.4 demonstrated better clinical and imaging profiles, including lower admission NIHSS scores and smaller ischemic core volumes. Multivariable logistic regression confirmed HIR, along with age and the presence of hemorrhagic transformation, as independent predictors of favorable outcomes.

Conclusions: In unsuccessfully reperfused patients with AIS-LVO, an HIR of <0.4 is associated with favorable outcomes, emphasizing on the importance of robust collateral circulation. This finding suggests that perfusion imaging and HIR evaluation could guide clinical decision-making and prognostication in this challenging patient subset.

Background and purpose: Patients with intracranial hypotension from spinal CSF leaks have increased choroid plexus volumes in response to CSF leakage. The purpose of this study was to assess changes in choroid plexus volumes in patients before and after spinal CSF leak repair.

Materials and methods: This was a retrospective, institutional review board-approved study on patients with spinal CSF leak who had pre- and post-CSF leak repair MRI examinations. Brain MRIs with contrast were performed on a 1.5/3T scanner with acquisition of 3D T1 postcontrast (eg, Bravo, MPRAGE, and so forth). Choroid plexus volumes at the level of the trigonum ventriculi were calculated for the left and right sides on all pre- and posttreatment MRIs using Visage-7 segmentation tools. Basic demographic data, type of CSF leak, and choroid plexus volumes were recorded for all patients. Basic 2-tailed t tests were used to compare choroid plexus volumes between the pre- and posttreatment groups.

Results: Twenty patients with spontaneous intracranial hypotension from spinal CSF leaks were included. Eleven patients (55%) had a type 1a (ventral tear) spinal CSF leak, 5 patients (25%) had type 1b (lateral tear), and 4 patients (20%) had a type 3 spinal CSF leak. The mean age was 47.6 years (SD, 13.8 years). The mean choroid plexus volumes pretreatment were 0.82 cm³ (SD, 0.29 cm³) compared with 0.38 cm³ (SD, 0.19 cm³) posttreatment (P value 0.01).

Conclusions: Significantly decreased choroid plexus volumes were seen in patients with spontaneous intracranial hypotension following spinal CSF leak repair. This finding highlights the modulation and dynamic role of the choroid plexus in states of low CSF volumes.

Background and purpose: Charcot-Bouchard Aneurysms (CBA) are tiny aneurysms arising from small perforating arteries. Despite the potentially catastrophic consequences of rupture of these aneurysms, the existence and prevalence of CBAs is controversial. The literature in this area is sparse with most previous studies based on radiological case reports of single hemorrhage or histopathological analysis. 7T MRI provides higher spatial resolution than 3T MRI that enables imaging of the small perforating arteries. We determined whether CBAs could be detected in vivo using 7T MRI.

Materials and methods: 94 patients with ischemic stroke collected in the Cam-SVD prospective cohort were retrospectively included; 75 of them had lacunar infarcts due to presumed small vessel disease and 19 had non-lacunar infarcts due to presumed cardioembolism or large artery disease. Contrast enhanced 3D time-of-flight (TOF) angiography (MRA) and structural sequences were performed by 7T MRI. Two neuroradiologists independently reviewed the MR scans to identify aneurysms on the lenticulostriate arteries (LSA) bilaterally.

Results: In 4 of the 94 subjects, CBAs were detected in the LSAs; of these three had a single CBA and one had two. The diameter of the parent vessel ranged from 0.26mm - 0.37mm, and the maximum diameter of the CBA ranged from 0.73mm - 1.39mm. Use of 3D images allowed differentiation of looped vessels, which could mimic aneurysms on 2D images, from true CBA.

Conclusions: We have demonstrated that 7T MRI can detect CBAs in vivo in humans. This technique could allow further longitudinal studies to determine the true prevalence and prognostic significance of CBAs.

Abbreviations: CBA: Charcot-Bouchard Aneurysms; LSA: lenticulostriate arteries; CamSVD: Cambridge 7T Cerebral Small Vessel Disease study; eGFR: estimated glomerular filtration rate; FA: flip angle.

Background and purpose: Intracranial solitary fibrous tumors (SFTs) and meningiomas are CNS tumors that share similar imaging manifestations but exhibit different clinical behaviors. This study aimed to compare ADC values and conventional imaging features, particularly pre-contrast T1-weighted signal intensity, between intracranial SFTs and meningiomas.

Materials and methods: We retrospectively evaluated 13 patients with pathologically proven intracranial SFTs and 27 patients with meningiomas who attended our hospital between January 2002 and December 2023. Signal intensity on pre-contrast T1-weighted imaging (compared to cerebral cortex), presence of dural tail sign, flow voids, hyperostosis, calcification, and normalized mean T1-weighted imaging values and mean ADC values were assessed.

Results: T1-weighted hyperintensity was significantly more frequent in SFTs (10/13, 76.9%) compared to meningiomas (5/27, 18.5%) (P=0.0010). Normalized mean T1-weighted imaging values (P=0.035) and normalized mean ADC values (P=0.039) were significantly higher in SFTs compared to meningiomas. A significant inverse correlation between normalized mean T1-weighted imaging and ADC values was observed in SFTs (R-squared=0.42, P=0.017). Binomial logistic regression analysis showed moderate efficacy in differentiating these tumors (mean cross-validation score=0.83). Dural tail sign, hyperostosis, and calcification were more frequent in meningiomas, although these differences were not statistically significant.

Conclusions: Pre-contrast T1-weighted signal intensity is a useful characteristic for differentiating intracranial SFTs from meningiomas, with hyperintensity compared to cerebral cortex being a distinctive feature of SFTs. The combination of normalized T1-weighted imaging and ADC values provides moderate diagnostic accuracy.

Abbreviations: SFT = solitary fibrous tumors.