AJNR. American journal of neuroradiology最新文献

Iatrogenic pseudoaneurysm is a rare but potentially fatal complication of a thyroid biopsy. However, a standard management strategy has not yet been established. We aimed to evaluate the efficacy and safety of ultrasound (US)-guided thrombin injection (TI) for thyroid pseudoaneurysms. This retrospective study included 7256 patients who underwent thyroid biopsy and TI from January 2020 to January 2024. The technical success, clinical efficacy, and complication rates were evaluated. A total of 0.1% (7/7256) of pseudoaneurysms developed after thyroid biopsy. Except for 1 case that showed obliteration with manual compression, the remaining 6 refractory aneurysms (0.08%) were managed with US-guided TI. All cases (100%) were successfully occluded with US-guided TI. No major complications were observed. One patient (16.7%) developed transient loss of consciousness, which spontaneously resolved within a few seconds. US-guided TI is an effective, relatively safe, and minimally invasive method for managing pseudoaneurysms after thyroid biopsy.

Background and purpose: Vertebrobasilar artery stent placement (VBS) is potentially effective in preventing recurrent posterior circulation strokes; however, the incidences of in-stent restenosis and stented-territory ischemic events based on the location of stent placement have rarely been investigated. We aimed to investigate the characteristics and prognosis of VBS between intracranial and extracranial.

Materials and methods: This study was single-center retrospective cohort study, and we obtained medical records of patients who underwent VBS. We compared clinical and periprocedural factors between extracranial and intracranial VBS. The primary outcomes included the incidence of in-stent restenosis (>50% reduction in lumen diameter) and stented-territory ischemic events. We compared the incidence of in-stent restenosis and stented-territory ischemic events by using Kaplan-Meier curves.

Results: Of the 105 patients, 41 (39.0%) underwent extracranial VBS, and 64 (61.0%) underwent intracranial VBS. During the follow-up, the incidences of in-stent restenosis and stented-territory ischemic events were 15.2% and 22.9%, respectively. The procedure time was longer (47.7 ± 19.5 minutes versus 74.5 ± 35.2 minutes, P < .001), and the rate of residual stenosis (≥30%) just after VBS was higher (2 [4.9%] versus 24 [37.5%], P < .001) in intracranial VBS than in extracranial VBS. Also, the incidences of in-stent restenosis were significantly higher in intracranial VBS than in extracranial VBS (4.9% versus 21.9%, P = .037). On the other hand, the incidences of stented-territory ischemic events (7.3% versus 32.8%, P < .001) were significantly higher in intracranial VBS than in extracranial VBS. The main mechanisms of stroke were artery-to-artery embolism (2 [66.7%]) in extracranial VBS, and artery-to-artery embolism (9 [42.9%]) and branch atheromatous disease (8 [38.1%]) in intracranial VBS. The Kaplan-Meier curve demonstrated a higher incidence of in-stent restenosis and stented-territory ischemic events in intracranial VBS than in extracranial VBS (P = .008 and P = .002, respectively).

Conclusions: During the follow-up, the incidence of in-stent restenosis and stented-territory ischemic events was higher in patients with intracranial VBS than in those with extracranial VBS. The higher rates of postprocedural residual stenosis might have contributed to the increased risk of in-stent restenosis. Furthermore, prolonged procedure time and additional stroke mechanism, including branch atheromatous disease, might be associated with a higher risk of stented-territory ischemic events in intracranial VBS.

Background and purpose: Mechanical thrombectomy is a fundamental intervention for acute ischemic stroke treatment. While conventional techniques are effective, cyclic aspiration (CyA) shows potential for better recanalization rates. We aim to investigate factors affecting CyA and compare them with static aspiration (StA).

Materials and methods: StA setup consisted of an aspiration pump connected to pressure transducer. CyA was tested with 5 subsequent iterations: single solenoid valve with air plus saline (i1) or saline alone (i2) as aspiration medium; 2 solenoid valves with air plus saline (i3) as aspiration medium; complete air removal and saline feeding (i4); and pressurized saline feeding (i5). To assess the efficacy of clot ingestion, the pressure transducer was replaced with a distal aspiration catheter. Moderately stiff clot analogs (15 mm) were used to investigate the ingestion quantified as clot relative weight loss. Additionally, the aspiration flow rate was assessed for each setup.

Results: With CyA i1, the amplitude of the achieved negative pressure waves declined with increasing frequencies but progressively increased with each subsequent iteration, achieving a maximum amplitude of 81 kPa for i5 at 1 Hz. Relative clot weight loss was significantly higher with i5 at 5 Hz than with StA (100% versus 37.8%; P = .05). Aspiration flow rate was lower with CyA than with StA (i5 at 5 Hz: 199.8 mL/min versus StA: 311 mL/min; P < .01).

Conclusions: CyA with the appropriate setup may represent an encouraging innovation in mechanical thrombectomy, offering a promising pathway for improving efficacy in clot ingestion and recanalization. The observed benefits warrant confirmation in a clinical setting.

Background and purpose: Brain atrophy occurs in the late stage of dementia, yet structural MRI is widely used in the work-up. Atrophy patterns can suggest a diagnosis of Alzheimer disease (AD) or frontotemporal dementia (FTD) but are difficult to assess visually. We hypothesized that the availability of a quantitative volumetric brain MRI report would increase neuroradiologists' accuracy in diagnosing AD, FTD, or healthy controls compared with visual assessment.

Materials and methods: Twenty-two patients with AD, 17 with FTD, and 21 cognitively healthy patients were identified from the electronic health systems record and a behavioral neurology clinic. Four neuroradiologists evaluated T1-weighted anatomic MRI studies with and without a volumetric report. Outcome measures were the proportion of correct diagnoses of neurodegenerative disease versus normal aging ("rough accuracy") and AD versus FTD ("exact accuracy"). Generalized linear mixed models were fit to assess whether the use of a volumetric report was associated with higher accuracy, accounting for random effects of within-rater and within-subject variability. Post hoc within-group analysis was performed with multiple comparisons correction. Residualized volumes were tested for an association with the diagnosis using ANOVA.

Results: There was no statistically significant effect of the report on overall correct diagnoses. The proportion of "exact" correct diagnoses was higher with the report versus without the report for AD (0.52 versus 0.38) and FTD (0.49 versus 0.32) and lower for cognitively healthy (0.75 versus 0.89). The proportion of "rough" correct diagnoses of neurodegenerative disease was higher with the report than without the report within the AD group (0.59 versus 0.41), and it was similar within the FTD group (0.66 versus 0.63). Post hoc within-group analysis suggested that the report increased the accuracy in AD (OR = 2.77) and decreased the accuracy in cognitively healthy (OR = 0.25). Residualized hippocampal volumes were smaller in AD (mean difference -1.8; multiple comparisons correction, -2.8 to -0.8; P < .001) and FTD (mean difference -1.2; multiple comparisons correction, -2.2 to -0.1; P = .02) compared with cognitively healthy.

Conclusions: The availability of a brain volumetric report did not improve neuroradiologists' accuracy over visual assessment in diagnosing AD or FTD in this limited sample. Post hoc analysis suggested that the report may have biased readers incorrectly toward a diagnosis of neurodegeneration in cognitively healthy adults.

We retrospectively reviewed the clinical and radiologic findings in 17 children with an aberrant cisternal cranial nerve 7 (CN7), and found that these patients had additional anomalies involving other pontine cranial nerves (CNs). The hallmark imaging feature identified in all patients was an aberrant cisternal segment of an enlarged-appearing CN7. The abnormal nerve coursed anteriorly toward the Gasserian ganglion, where it fanned out toward the internal auditory canal, Meckel cave, or both. This finding was accompanied by a small cisternal CN5, which often had a lateral bowed appearance. CN5 and CN7 were abnormally close to each other. Meckel's cave appeared widened posteriorly and often was close to or merged with the internal auditory canal. Other abnormalities in the pontine CNs included CN8 deficiency in most children and variable CN6 deficiency. This constellation of findings was most often discovered in children having an MR evaluation for sensorineural hearing loss, and most patients had preserved facial nerve function. In patients with available genetic testing, no pathogenic variants were observed. Interestingly, in 13 children with an available birth history, 9 were notable for maternal or gestational diabetes (69%), suggesting a possible early intrauterine insult to the developing nerves.

Background and purpose: Mechanical thrombectomy (MT) along with emergent carotid stent placement (eCAS) has been suggested to have a greater benefit in patients with tandem lesions (TL), compared with other strategies of treatment. Nonetheless, there is no agreement on whether the intracranial occlusion should be treated before the cervical ICA lesion, or vice versa. In this retrospective multicenter study, we sought to compare clinical and procedural outcomes of the 2 different treatment approaches in patients with TL.

Materials and methods: The prospective databases of 17 comprehensive stroke centers were screened for consecutive patients with TL who received MT and eCAS. Patients were divided in 2 groups based on whether they received MT before eCAS (MT-first approach) or eCAS before MT (eCAS-first approach). Propensity score matching was used to estimate the effect of the retrograde-versus-anterograde approach on procedure-related and clinical outcome measures. These included the modified TICI score 2b-3, other procedure-related parameters and adverse events after the endovascular procedure, and the ordinal distribution of the 90-day mRS scores.

Results: A total of 295 consecutive patients were initially enrolled. Among them, 208 (70%) received MT before eCAS. After propensity score matching, 56 pairs of patients were available for analysis. In the matched population, the MT-first approach resulted in a higher rate of successful intracranial recanalization (91% versus 73% in the eCAS-first approach, P = .025) and a mean shorter groin-to-reperfusion time (72 [SD, 38] minutes versus 93 [SD, 50] minutes in the anterograde approach, P = .017). Despite a higher rate of efficient recanalization in the MT-first group, we did not observe a significant difference regarding the ordinal distribution of the 90-day mRS scores. Rates of procedure-related adverse events and the occurrence of both parenchymal hemorrhage types 1 and 2 were comparable.

Conclusions: Our study demonstrates that in patients with TL undergoing endovascular treatment, prioritizing the intracranial occlusion is associated with an increased rate of efficient MT and faster recanalization time. However, this strategy does not have an advantage in long-term clinical outcome. Future controlled studies are needed to determine the optimal treatment technique.

Background and purpose: Recently, artificial intelligence tools have been deployed with increasing speed in educational and clinical settings. However, the use of artificial intelligence by trainees across different levels of experience has not been well-studied. This study investigates the impact of artificial intelligence assistance on the diagnostic accuracy for intracranial hemorrhage and large-vessel occlusion by medical students and resident trainees.

Materials and methods: This prospective study was conducted between March 2023 and October 2023. Medical students and resident trainees were asked to identify intracranial hemorrhage and large-vessel occlusion in 100 noncontrast head CTs and 100 head CTAs, respectively. One group received diagnostic aid simulating artificial intelligence for intracranial hemorrhage only (n = 26); the other, for large-vessel occlusion only (n = 28). Primary outcomes included accuracy, sensitivity, and specificity for intracranial hemorrhage/large-vessel occlusion detection without and with aid. Study interpretation time was a secondary outcome. Individual responses were pooled and analyzed with the t test; differences in continuous variables were assessed with ANOVA.

Results: Forty-eight participants completed the study, generating 10,779 intracranial hemorrhage or large-vessel occlusion interpretations. With diagnostic aid, medical student accuracy improved 11.0 points (P < .001) and resident trainee accuracy showed no significant change. Intracranial hemorrhage interpretation time increased with diagnostic aid for both groups (P < .001), while large-vessel occlusion interpretation time decreased for medical students (P < .001). Despite worse performance in the detection of the smallest-versus-largest hemorrhages at baseline, medical students were not more likely to accept a true-positive artificial intelligence result for these more difficult tasks. Both groups were considerably less accurate when disagreeing with the artificial intelligence or when supplied with an incorrect artificial intelligence result.

Conclusions: This study demonstrated greater improvement in diagnostic accuracy with artificial intelligence for medical students compared with resident trainees. However, medical students were less likely than resident trainees to overrule incorrect artificial intelligence interpretations and were less accurate, even with diagnostic aid, than the artificial intelligence was by itself.

Background and purpose: Periprocedural intracranial hemorrhage is one of common complications after stent placement for symptomatic intracranial atherosclerotic stenosis. This study was conducted to demonstrate predictors and long-term outcomes of periprocedural intracranial hemorrhage after stent placement for symptomatic intracranial atherosclerotic stenosis.

Materials and methods: We retrospectively analyzed patients with symptomatic intracranial atherosclerotic stenosis stent placement in a prospective cohort at a high-volume stroke center. Clinical, radiologic, and periprocedural characteristics and long-term outcomes were reviewed. Periprocedural intracranial hemorrhage was classified as procedure-related hemorrhage (PRH) and non-procedure-related hemorrhage (NPRH). The long-term outcomes were compared between patients with PRH and NPRH, and the predictors of NPRH were explored.

Results: Among 1849 patients, 24 (1.3%) had periprocedural intracranial hemorrhage, including PRH (4) and NPRH (20). The postprocedural 30-day mRS was 0-2 in 9 (37.5%) cases, 3-5 in 5 (20.8%) cases, and 6 in 10 (41.7%) cases. For the 14 survivors, the long-term (median of 78 months) mRS were 0-2 in 10 (76.9%) cases and 3-5 in 3 (23.1%) cases. The proportion of poor long-term outcomes (mRS ≥3) in patients with NPRH was significantly higher than those with PRH (68.4% versus 0%, P = .024). Anterior circulation (P = .002), high preprocedural stenosis rate (P < .001), and cerebral infarction within 30 days (P = .006) were independent predictors of NPRH after stent placement.

Conclusions: Patients with NPRH had worse outcomes than those with PRH after stent placement for symptomatic ICAS. Anterior circulation, severe preprocedural stenosis, and recent infarction are independent predictors of NPRH.

Background and purpose: Hemangioblastoma is a rare vascular tumor that occurs within the central nervous system in children. Differentiating hemangioblastoma from other posterior fossa tumors can be challenging on imaging, and preoperative diagnosis can change the neurosurgical approach. We hypothesize that a "lightbulb sign" on the arterial spin-labeling (ASL) sequence (diffuse homogeneous intense hyperperfusion within the solid component of the tumor) will provide additional imaging finding to differentiate hemangioblastoma from other posterior fossa tumors.

Materials and methods: In this retrospective comparative observational study, we only included pathology-proved cases of hemangioblastoma, while the control group consisted of other randomly selected pathology-proved posterior fossa tumors from January 2022 to January 2024. Two blinded neuroradiologists analyzed all applicable MRI sequences, including ASL sequence if available. ASL was analyzed for the lightbulb sign. Disagreements between the radiologists were resolved by a third pediatric neuroradiologist. χ² and Fisher exact test were used to analyze the data.

Results: Ninety-five patients were enrolled in the study; 57 (60%) were boys. The median age at diagnosis was 8 years old (interquartile range: 3-14). Of the enrolled patients, 8 had hemangioblastoma, and 87 had other posterior fossa tumors, including medulloblastoma (n = 31), pilocytic astrocytoma (n = 23), posterior fossa ependymoma type A (n = 16), and other tumors (n = 17). The comparison of hemangioblastoma versus nonhemangioblastoma showed that peripheral edema (P = .02) and T2-flow void (P = .02) favor hemangioblastoma, whereas reduced diffusion (low ADC) (P = .002) and ventricular system extension (P = .001) favor nonhemangioblastoma tumors. Forty-two cases also had ASL perfusion sequences. While high perfusion favors hemangioblastoma (P = .03), the lightbulb sign shows a complete distinction because all the ASL series of hemangioblastoma cases (n = 4) showed the lightbulb sign, whereas none of the nonhemangioblastoma cases (n = 38) showed the sign (P < .001).

Conclusions: Lightbulb-like intense and homogeneous hyperperfusion patterns on ASL are helpful in diagnosing posterior fossa hemangioblastoma in children.

Background and purpose: Alterations of the basilar artery (BA) anatomy have been suggested as a possible MRA feature of Fabry disease (FD). Nonetheless, no information about their clinical or pathophysiologic correlates is available, limiting our comprehension of the real impact of vessel remodeling in FD.

Materials and methods: Brain MRIs of 53 subjects with FD (mean age, 40.7 [SD, 12.4] years; male/female ratio = 23:30) were collected in this single-center study. Mean BA diameter and its tortuosity index were calculated on MRA. Possible correlations between these metrics and clinical, laboratory, and advanced imaging variables of the posterior circulation were tested. In a subgroup of 20 subjects, a 2-year clinical and imaging follow-up was available, and possible longitudinal changes of these metrics and their ability to predict clinical scores were also probed.

Results: No significant association was found between MRA metrics and any clinical, laboratory, or advanced imaging variable (P values ranging from -0.006 to 0.32). At the follow-up examination, no changes were observed with time for the mean BA diameter (P = .84) and the tortuosity index (P = .70). Finally, baseline MRA variables failed to predict the clinical status of patients with FD at follow-up (P = .42 and 0.66, respectively).

Conclusions: Alterations of the BA in FD lack of any meaningful association with clinical, laboratory, or advanced imaging findings collected in this study. Furthermore, this lack of correlation seems constant across time, suggesting stability over time. Taken together, these results suggest that the role of BA dolichoectasia in FD should be reconsidered.