AJNR. American journal of neuroradiology最新文献

Background and purpose: Deep learning (DL) reconstruction methods have shown promise in accelerating 2D MRI sequences but have yet to be extensively validated for routine 3D volumetric MRI applications. Our purpose was to assess the diagnostic quality of a novel DL-accelerated 3D T1-MPRAGE compared with a state-of-the-art wave-controlled aliasing in parallel imaging (Wave-CAIPI) accelerated 3D T1-MPRAGE for evaluating intracranial enhancing lesions.

Materials and methods: This prospective study was approved by the Institutional Review Board. Patients undergoing contrast-enhanced brain MRI in an outpatient setting were scanned on 3T MRI systems. The imaging protocol included a state-of-the-art Wave-CAIPI postcontrast T1-MPRAGE (acceleration factor [R] = 2 × 2, acquisition time [TA] = 2:11 minutes) and a research-based postcontrast DL-T1-MPRAGE (R = 2 × 2, TA = 2:11 minutes). The DL-based reconstruction process involved 2 steps. The first step, inspired by variational networks, involved 6 iterations alternating between data consistency updates and neural network evaluation. The second step applied a super-resolution algorithm for further image enhancement. Two independent neuroradiologists conducted a blinded, randomized head-to-head comparison of the 2 sequences by using a previously published scale across the following criteria: visualization of dural, parenchymal, leptomeningeal, and ependymal enhancement; sharpness; noise; artifacts; and overall diagnostic quality. A third board-certified neuroradiologist adjudicated cases with discrepant ratings. Noninferiority of DL-T1-MPRAGE was tested by using a 15% margin.

Results: A total of 115 patients (68 women/47 men, mean age = 54 ± 10 years) were included. The top 3 clinical indications were: neoplasm (52%), vascular lesions (24%), and headache (8%). DL-T1-MPRAGE was noninferior to Wave-CAIPI T1-MPRAGE for delineating enhancing lesions with unanimous agreement in all cases with enhancing pathology. It was also noninferior in terms of noise perception (P < .0001), artifact (P < .0001), sharpness (P = .001), and overall diagnostic quality (P < .0001). DL-T1-MPRAGE provided equivalent visualization of small, subtle enhancing parenchymal, dural, and leptomeningeal lesions.

Conclusions: The highly accelerated postcontrast DL-T1-MPRAGE demonstrated noninferior image quality compared with the clinically validated Wave-CAIPI T1-MPRAGE accelerated sequence while offering enhanced visualization of subtle enhancing lesions.

Background and purpose: Stroke is a leading cause of morbidity and mortality around the world, with LVO having a disproportionate impact on patient outcomes. Our aim was to assess the feasibility and accuracy of a deep learning (DL) model to identify acute MCA occlusion by using high-resolution NCCT imaging data.

Materials and methods: In this study, a total of 4648 consecutive examinations (July 2021 to December 2023) were retrospectively used for model training and validation, while an additional 1011 consecutive examinations (January 2024 to August 2024) were used for independent testing. By means of high-resolution NCCT acquired at a 1.0-mm slice thickness or less, MCA thrombus was labeled by using same-day CTA as ground truth. A 3D DL model was trained for per-voxel thrombus segmentation, with the sum of positive voxels used to estimate likelihood of acute MCA occlusion.

Results: For detection of MCA M1 segment acute occlusion, the model yielded an area under the receiver operator curve (AUROC) of 0.952 [0.904-1.00], accuracy of 93.6% [88.1%-98.2%], sensitivity of 90.9% [83.1%-100%], and specificity of 93.6% [88.0%-98.3%]. Inclusion of M2 segment occlusions reduced performance only slightly, yielding an AUROC of 0.884 [0.825-0.942], accuracy of 93.2% [85.1%-97.2%], sensitivity of 77.4% [69.3%-92.2%], and specificity of 93.6% [85.1%-97.8%].

Conclusions: A DL model can detect acute MCA occlusion from high-resolution NCCT with accuracy approaching that of CTA. By means of this tool, most candidate thrombectomy patients may be identified with NCCT alone, possibly aiding stroke triage in settings that lack CTA or are otherwise resource-constrained.

Background and purpose: Different types of software to analyze CTP data in patients with ischemic stroke are available. Assessing their comparability and interchangeability in clinical practice represents an only partly addressed question. Here we present a comparison between 2 distinct commercially available CTP types of software, analyzing their performance in estimating ischemic core volumes and evaluating the possible impact on patient stratification strategies to endovascular treatment (EVT).

Materials and methods: In this single-center retrospective monocentric observational study, 109 patients with stroke (mean age = 72.4 ± 12.4 years, M/F = 41/68) were included from January 2023 to June 2024. To evaluate the possible clinical relevance of the use of different types of software, DAWN and DEFUSE-3 criteria were applied to stratify the population. The software was compared (Viz.ai and syngo.via), and for both programs, different relative CBF thresholds were used to define the ischemic core.

Results: The 2 software programs showed significant differences in core volume identification, independently from the used threshold (all comparisons with P < .001). When the DAWN criteria for EVT were applied, the use of one software compared with another led to a significant (P = .005) increase in subjects excluded from EVT. The use of a more conservative threshold significantly reduced (P = .68) this discrepancy.

Conclusions: Within-subject analysis of CTP data with different software and thresholds might lead to significantly different core estimation and treatment stratification in patients with stroke. Though this effect can be mitigated by using specific thresholds, the physician should be aware of these differences when evaluating CTP data in clinical practice, given the possible direct implications in their decision-making process.

Background and purpose: The feasibility and safety of using 8F sheaths for endovascular treatment via the transradial approach (TRA) remain underexplored. This study evaluated whether the use of an 8F guiding catheter with or without an 8F sheath affects procedural success rates and access-site complications.

Materials and methods: We retrospectively reviewed 211 unruptured intracranial aneurysms in 207 patients treated via TRA with an 8F guiding catheter at 3 institutions between March 2021 and January 2025. Patients were divided into 2 groups: those treated with a sheath (Group S) and those without a sheath (Group NS). Propensity score matching was used to control for baseline differences when assessing the association between 8F sheath use and complication rates.

Results: A total of 44 aneurysms (21%) were treated via TRA by using an 8F guiding catheter with a sheath, achieving successful treatment in all cases. Propensity score matching resulted in 30 paired aneurysms from Group S and Group NS. The incidence of radial artery occlusion and radial artery spasm was significantly lower in Group S (0% and 20%, respectively) compared with Group NS (30% and 53%, respectively; P = .002 and .015). No significant differences were observed between the groups in access-site or non-access-site complications, nor in procedural success rates.

Conclusions: The use of an 8F guiding catheter with an 8F sheath for the treatment of unruptured intracranial aneurysms via the TRA appears feasible and may reduce the risk of radial artery occlusion and radial artery spasm without increasing the incidence of access-site or non-access-site complications.

Parathyroid lipoadenoma (PLA) is a rare cause of primary hyperparathyroidism and is over 50% adipose tissue, which complicates preoperative localization. We aimed to describe clinical and imaging features of PLA in this case series. We retrospectively reviewed 4 patients with pathologically confirmed PLA and biochemical evidence of primary hyperparathyroidism. All patients exhibited elevated PTH and upper-normal to elevated calcium levels. PLAs demonstrated hyperechogenicity on ultrasonography, fat-equivalent attenuation on CT, and increased uptake on sestamibi SPECT/CT. Surgical excision resulted in notable intraoperative PTH decline and postoperative biochemical cure. Pathology confirmed >50% stromal fat in all cases. In conclusion, PLA presents unique diagnostic challenges because of its imaging characteristics. Awareness of these features and a multimodal imaging approach are key to accurate localization and successful surgical management.

Background: Middle meningeal artery embolization (MMAE) is increasingly used to treat chronic subdural hematomas, arteriovenous fistulas, and meningiomas. Less commonly, MMAE is performed for pseudoaneurysms and aneurysms of the middle meningeal artery (MMA). While procedural safety and efficacy in the context of the former diseases is well know, data on MMA embolization for MMA aneurysms and pseudo-aneurysms are scarce.

Purpose: The purpose of this study was to systematically review the safety, efficacy, and procedural details of MMAE for pseudoaneurysms and aneurysms.

Data source: We conducted a systematic review using PubMed/Medline and GoogleScholar, targeting studies published in English since 1994.

Study selection: Original research studies and case reports involving adult patients (18 years of age or older) with pseudoaneurysms and aneurysms treated with MMAE were included. Data on disease etiology, complications, outcomes, procedural techniques, and embolization materials were analyzed using descriptive statistics.

Data synthesis: Of 1690 identified studies, 600 underwent full-text review, and 28 studies/case reports focusing on MMAE for pseudoaneurysms and aneurysms were included in the final analysis. The treated cases were mainly traumatic (54.84%, 17/31), followed by tumor-related (16.13%, 5/31), iatrogenic (12.90%/4/31), miscellaneous (9.68% 3/31), and mycotic (3.2.3%, 1/31) etiologies. The most used embolization materials were coils (38.71%, 12/31), n-BCA (29.03%, 9/31), ethylene-vinyl alcohol copolymer (EVOH, Onyx) (19.35%, 6/31), and polyvinyl alcohol (9.68%, 3/31). Complete occlusion of the aneurysm or pseudoaneurysm was achieved in all cases. Symptom improvement related to MMAE occurred in 28 of 31 patients (90.32%). If symptoms remained, they were mild, such as mild hemiparesis (n = 3). Complications of MMAE occurred in 1 case, namely nontarget embolization of middle cerebral artery branches due to occult anastomoses between the MMA and middle cerebral artery related to prior trauma; however, the patient experienced no permanent deficits.

Limitations: Available data on MMAE for MMA aneurysms and pseudoaneurysms are scarce and from case reports only, limiting generalizability. Confirmation in larger, multicenter cohort studies is needed.

Conclusion: MMAE appears to be a safe and effective treatment for pseudoaneurysms and aneurysms, with minimal complications and high angiographic success rates.

Background and purpose: Endovascular thrombectomy (EVT) is an effective treatment of acute ischemic stroke caused by large-vessel occlusion (AIS-LVO) of the anterior circulation, and technical success is essential to maximize outcomes. Increased EVT pass counts have been associated with reduced procedural efficacy and worse patient outcomes. We examined the impact of pre-EVT cerebral perfusion imaging parameters on clinical outcomes in patients with high EVT pass numbers.

Materials and methods: We performed a multicenter retrospective analysis of patients with AIS-LVO who had pretreatment CTA and CTP imaging and a pass count ≥3. Baseline NCCT imaging was analyzed according to ASPECTS. Ischemic core was defined as relative CBF <30% on CTP. Collateral blood flow was evaluated using the modified Tan scoring system on CTA, hypoperfusion intensity ratio (time-to-maximum >10 seconds/>6-second volumetric ratio) on CTP, and venous outflow (VO) on CTA. The primary outcome was favorable clinical outcomes (mRS 0-2) at 90 days.

Results: One hundred seventy-eight patients met the inclusion criteria and were dichotomized into favorable (mRS 0-2, 29%) and unfavorable outcome (mRS 3-6, 71%) groups. Patients with favorable outcomes had lower blood glucose levels (mean, 115 mg/dL; interquartile range [IQR], 102-128 versus 126 mg/dL [IQR, 103-156; P = .03) and lower baseline NIHSS scores (median, 9; IQR, 6.5-13.5 versus 17; IQR, 13-20; P < .001) compared with those with unfavorable outcomes. On pre-EVT imaging, favorable patients had smaller ischemic core volumes (median, 2 mL; IQR, 0-14 versus 16 mL; IQR, 0-39; P < .001), higher ASPECTS (median, 9; IQR, 7-10 versus 7; IQR, 6-9; P = .001), a higher frequency of favorable CTA collaterals (87% versus 57%, P < .001), a more favorable hypoperfusion intensity ratio (median, 0.3; IQR, 0.2-0.5 versus 0.5; IQR, 0.4-0.6; P < .001), and higher rates of favorable VO (73% versus 15%; P < .001). In a regression analysis, favorable outcome was independently associated with lower-presentation NIHSS (OR, 0.84; 95% CI, 0.76-0.93; P < .001), successful reperfusion (modified TICI score 2b-3; OR, 4.95; 95% CI, 1.18-20.72; P = .03), and favorable VO (OR, 12.35; 95% CI, 4.23-36.10; P < .001).

Conclusions: In Patients with AIS-LVO treated with EVT that involved ≥3 passes, lower presentation NIHSS, successful reperfusion, and favorable VO were associated with an increased likelihood of a favorable outcome.

The advent of anti-amyloid therapies (AATs) for Alzheimer disease (AD) has elevated the importance of MRI surveillance for amyloid-related imaging abnormalities (ARIA) such as microhemorrhages and siderosis (ARIA-H) and edema (ARIA-E). We report a literature review and early quality-assurance experience with an FDA-cleared decision support artificial intelligence (AI) tool intended for detection of ARIA in MRI clinical workflows. The AI system improved the sensitivity for detection of subtle ARIA-E and ARIA-H lesions but at the cost of a reduction in specificity. We propose a tiered workflow combining protocol harmonization and expert interpretation with an AI overlay review. AI-assisted ARIA detection is a paradigm shift that offers great promise to enhance patient safety as disease-modifying therapies for AD gain broader clinical use; however, some pitfalls need to be considered.

Aurora (https://aurora-report.com/) is an open-source Web application that introduces structured, standardized reporting for neuroimaging, currently focused on dementia and movement disorders. Developed by and for radiologists and neuroradiologists, Aurora provides a stepwise workflow to support evaluation and reporting. It includes validated atrophy scales such as medial temporal lobe atrophy, global cortical atrophy, entorhinal cortex atrophy, and Koedam posterior atrophy, as well as a systematic approach to describe small vessel disease based on Standards for Reporting Vascular Changes on Neuroimaging, version 2 criteria. Each section offers literature-based guidance and annotated examples for scoring. The platform features built-in calculators for atrophy and movement disorder metrics, including midbrain and pons measurements, midbrain-to-pons ratio, Magnetic Resonance Parkinsonism Index (MRPI), and MRPI version 2.0. Aurora generates structured reports in English (US) or Portuguese (PT). To our knowledge, it is the first freely available platform to unify standardized reporting and calculation for dementia and movement disorders.

CSF-venous fistulas are a common and increasingly recognized cause of spontaneous intracranial hypotension. Most CSF-venous fistulas occur in the thoracic spine and usually arise from nerve root sleeve diverticula. Myelography in the lateral decubitus position is necessary to detect and localize these fistulas, because this technique maximizes contrast density within diverticula, thereby permitting visualization of draining veins. Many modifications to decubitus myelography have been employed in an attempt to improve the conspicuity of CSF-venous fistulas. In theory, maximizing the subarachnoid-venous pressure gradient during imaging should increase contrast flow through CSF-venous fistulas, improving detection of these sometimes-subtle leaks. Augmentation of intrathecal pressure through saline injection before myelography is a simple technique to achieve this and is common in many practices. However, only one prior case report has demonstrated the impact of pressurization on the visualization of a CSF-venous fistula. In this multi-institutional, retrospective case series, we report on a larger cohort of patients in whom CSF-venous fistulas were either occult or nondefinite on myelography without saline pressurization and subsequently definitely seen on myelography with saline pressurization. While our study design precludes determining the incremental yield of saline infusion, it nonetheless provides further support for the value of saline pressurization during myelography in patients with suspected CSF-venous fistulas.