AJNR. American journal of neuroradiology最新文献

Background and purpose: Although high-resolution conebeam CT (HR-CBCT) is used for immediate evaluation of stent apposition, studies using this technique to evaluate flow diverter (FD) endothelialization during follow-up are limited. The study aims to investigate the potential of HR-CBCT in assessing FD endothelialization and identify factors influencing poor endothelialization.

Materials and methods: The clinical and imaging data of patients with unruptured intracranial aneurysms (UIAs) treated by FDs from March 2019 to October 2023 were retrospectively analyzed. HR-CBCT was used for immediate evaluation of stent apposition, and FD endothelialization at 3, 6, and 12 months postimplantation was evaluated by using HR-CBCT and digital subtraction angiography. Multivariate logistic regression analysis was used to identify factors associated with poor endothelialization.

Results: Among 402 FDs implanted for 446 aneurysms in 378 patients, 41 showed incomplete stent apposition (ISA) in postimplantation HR-CBCT scans. The aneurysm-occlusion rate at 12 months postimplantation was 84.8% (378/446), with 8.7% (35/402) of the FDs exhibiting in-stent stenosis (ISS). At 12 months postimplantation, 343 (85.1%) FDs showed good endothelialization, while 59 (14.9%) exhibited poor endothelialization. Multivariate logistic regression analysis identified age ≥60 years (OR = 2.209; 95% CI, 1.053-4.635; P = .04), a large aneurysm lumen inflow angle (OR = 1.102; 95% CI, 1.071-1.135; P < .001), parent artery excessive tortuosity (OR = 9.402; 95% CI, 1.141-77.479; P = .04), and ISA (OR = 10.967; 95% CI, 4.290-28.035; P < .001) as independent risk factors for poor endothelialization.

Conclusions: HR-CBCT can accurately evaluate FD endothelialization and ISS of UIAs after FD implantation. Age ≥60 years, a large aneurysm lumen inflow angle, parent artery excessive tortuosity, and ISA are independent risk factors for poor endothelialization.

Background and purpose: Epidural spinal cord compression (ESCC) is an important cause of disability among patients with cancer. Early detection is crucial for optimizing clinical outcomes. MRI is the preferred imaging technique for ruling out ESCC and is frequently requested in radiology departments, particularly in the emergent setting. However, data on the efficacy and diagnostic yield of total spine MRI for the diagnosis of ESCC in oncology patients remain limited. This study evaluates the frequency of positive findings and associated risk factors in a tertiary cancer center.

Materials and methods: This retrospective study included patients who underwent total spine MRI for the assessment of ESCC during a 3-year period. A standardized noncontrast MRI protocol was used. Clinical and imaging data, including patient demographics (sex, age); tumor pathology; tumor, node, metastasis stage; ESCC grade; symptoms; prior treatments (radiation therapy, surgery, chemotherapy); and ordering physician/department, were retrospectively reviewed. Patients were categorized into 2 groups on the basis of the presence or absence of cord compression (ESCC 2 or 3). Associations between ESCC and other variables were assessed via the Wilcoxon rank-sum test, Pearson χ² test, and Fisher exact test. Statistical significance was defined as P < .05.

Results: Among 289 patients (median age, 66 years; 148 women) and 300 total spine MRI examinations, ESCC was detected in 18 cases (6.0%). Significant associations with ESCC included advanced tumor, node, metastasis stage (P = .028) and prior treatments, such as radiation to the site of compression (P = .002), decompression surgery (P = .011), and recent systemic chemotherapy (P < .001). Bone metastases to the spine on body CT examinations performed within 2 weeks before MRI also correlated with ESCC (P < .001). Notably, no ESCC cases occurred in patients without spine bone metastases on recent body CT or in those with less than stage IV disease. Patient symptoms did not correlate with ESCC presence (P = .3).

Conclusions: This study suggests that the diagnostic yield of total spine MRI for ESCC in oncology patients is relatively low and may be improved by refining the selection criteria. Patients with advanced-stage disease, prior spinal interventions, and bone metastases on recent body CT may be at higher risk.

Background and purpose: Prolonged venous transit (PVT), derived from perfusion imaging, serves as a surrogate for venous outflow (VO) impairment and has been associated with worse outcomes in acute ischemic stroke due to large-vessel occlusion (AIS-LVO). However, the differential impact of superficial-versus-deep venous drainage impairment on functional outcomes remains unclear. PVT1 and PVT2 were used as surrogates for superficial and deep VO impairment, respectively.

Materials and methods: We retrospectively analyzed 128 patients with AIS-LVO from a prospective registry who underwent successful mechanical thrombectomy (modified TICI 2b/2c/3) with available baseline CTP and 90-day mRS scores. PVT- was defined as the absence of time-to-maximum (Tmax) ≥10 seconds in the posterior superior sagittal sinus (SSS) or torcula (no VO impairment). PVT1 was defined as the presence of Tmax ≥10 seconds in the posterior SSS only (superficial VO impairment); and PVT2, as the presence of Tmax ≥10 seconds at the torcula with or without posterior SSS involvement (deep VO impairment). Multivariable logistic regression assessed the association between PVT gradation and the 90-day mRS score.

Results: The proportion of patients achieving favorable outcomes (mRS ≤2) declined stepwise across the PVT gradation: 60.9% in PVT-, 42.1% in PVT1, and 22.7% in PVT2. After we adjusted for age, admission NIHSS score, hypertension, hemorrhagic transformation, IV thrombolysis, and the modified TICI score, PVT gradation remained independently associated with reduced odds of favorable outcome. This association was primarily driven by the PVT2 group, with an adjusted OTR of 0.230 (95% CI, 0.068-0.780) compared with PVT- group.

Conclusions: PVT gradation based on Tmax ≥10 seconds timing in distinct venous territories provides prognostic insight into the differential contributions of superficial-versus-deep venous drainage dysfunction, supporting the use of PVT as a meaningful VO imaging biomarker. Deep VO impairment, as reflected by PVT2, is the primary driver of worse functional outcomes despite successful reperfusion in AIS-LVO, indicating its stronger negative prognostic impact compared with superficial VO impairment. These findings can help inform prognosis and postacute management strategies.

Background and purpose: Data regarding predictive factors for postoperative neurological improvement after endovascular treatment for spinal vascular lesions are extremely limited. Our aim was to perform a subgroup analysis of spinal vascular lesions from the Japanese Registry of Neuroendovascular Therapy (JR-NET) 2-4 (2007-2019) to review the current status of endovascular treatment for spinal vascular lesions in Japan and to identify factors associated with postoperative neurologic improvement after endovascular treatment for spinal vascular lesions.

Materials and methods: The treatment statuses of 384 spinal dural arteriovenous fistula (SDAVF), 115 spinal perimedullary arteriovenous fistula (SPAVF), and 56 spinal intramedullary arteriovenous malformation (SIAVM) cases were assessed along with the correlations between each variable and the primary end point of postoperative neurologic improvement.

Results: Treatment was radical in 81.9% of SDAVFs, palliative or presurgical in 73.2% of SIAVMs, and radical or palliative/presurgical in 47.0% and 51.3%, respectively, of SPAVF cases. Total occlusion was achieved in 60.2% of SDAVF, 30.4% of SPAVF, and 17.9% of SIAVM cases. Treatment-related complications occurred in 7.3% of SDAVF, 14.8% of SPAVF, and 8.9% of SIAVM cases. Postoperative neurologic improvement was achieved in 52.3% of SDAVF, 28.7% of SPAVF, and 23.2% of SIAVM cases. In multivariate analyses, such improvement in SDAVFs was correlated with total shunt obliteration and the absence of complications. Postoperative neurologic improvement in SPAVFs was associated with the absence of complications and was inversely associated with hemorrhagic onset in multivariate analyses. In SIAVM, a negative correlation with hemorrhagic onset was found in only univariate analysis. For the analysis of treatment outcomes by institutional case volume, total obliteration of SDAVFs and postoperative neurologic improvement of SPAVFs were significantly higher in the high-volume group.

Conclusions: In Japan, treatment of spinal vascular lesions was administered with relative safety, and better outcomes were achieved at high-volume centers. In SDAVFs, total shunt obliteration and avoidance of complications are critical factors for achieving neurologic recovery. In SPAVFs, selecting an appropriate treatment strategy based on the vascular architecture is essential to minimize complications for achieving favorable postoperative outcomes. In SIAVMs, disease management should take precedence over radical intervention. Furthermore, the disruption of neurologic recovery by hemorrhagic onset in both SPAVFs and SIAVMs highlights the importance of early diagnosis and timely intervention.

Background and purpose: Net water uptake (NWU) in the infarct core of patients with ischemic stroke has been correlated with clinical outcome and lesion age, which could aid in treatment selection. Traditional NWU measurement requires CTP, limiting its clinical applicability. We aimed to develop and evaluate an automated method to measure NWU using only NCCT and CTA.

Materials and methods: We included 90 patients with ischemic stroke with known onset time and available NCCT, CTA, and CTP from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry and MR CLEAN-LATE trial. Using deep learning, we automatically segmented the infarct core and hypoperfused area from NCCT and CTA images. NWU was calculated as the relative difference in density between these affected regions and their contralateral counterparts. We included the hypoperfused area because it represents potentially salvageable tissue, and additional NWU analyses in this region could provide insights into ischemic injury progression. We compared this automated CTA-NCCT-based approach with the traditional CTP-NCCT-based approach by assessing their agreement (intraclass correlation coefficient [ICC], Bland-Altman analysis) and accuracy in identifying patients within 4.5 hours of stroke onset (receiver operating characteristic analysis, DeLong test for areas under the curve [AUC] comparison).

Results: NWU measured in the core (CTP-NCCT-based: median 4.1%, interquartile range [2.7-6.6]; CTA-NCCT-based: 3.2%, [2.1-5.2]) showed good agreement between approaches (ICC 0.81, 95% CI, 0.73-0.87; mean difference 0.43% [-4.6% to +5.5%]). NWU in the hypoperfused area (CTP-NCCT-based: 2.3%, [1.3-4.1]; CTA-NCCT-based: 2.4%, [0.9-3.9]) showed excellent agreement (ICC 0.93, 95% CI, 0.90-0.96; mean difference 0.17%, -1.54% to +1.88%). For core-based NWU, both approaches detected significantly lower values in patients within versus beyond 4.5 hours (CTP-NCCT-based: 3.7% versus 10%; P < .001; CTA-NCCT-based: 3.1% versus 11%; P < .001) with similar accuracy (AUC, 0.87; P = .88). For hypoperfused area-based NWU, neither approach showed significant differences between patients within versus beyond 4.5 hours (CTP-NCCT-based: 2.3% versus 4.4%; P = .31; CTA-NCCT-based: 2.3% versus 4.7%; P = 0.13) and both had lower accuracy than core-based NWU classification (AUC,: CTP-NCCT-based 0.59, CTA-NCCT-based 0.63; P = 0.81).

Conclusions: The automated CTA-NCCT-based approach shows good agreement with the traditional CTP-NCCT-based method for NWU measurement and achieves similar accuracy in identifying patients within 4.5 hours of onset. External validation is needed to confirm these findings.

CSF-venous fistulas are a common cause of spontaneous intracranial hypotension. Most CSF-venous fistulas occur in the thoracic spine, and recently described myelographic techniques have been primarily tailored to localize fistulas in this location.^{1 -4} However, a small subset of CSF-venous fistulas can occur at the superior or inferior ends of the spine, ranging from the skull base to the sacrum. In this Video Article, we discuss modifications to decubitus myelography needed to safely and confidently diagnose CSF-venous fistulas at the extremes of the spine, including the skull base and sacrum.^{5 -7} We also show unique case examples of these relatively uncommon leaks, which were found using decubitus digital subtraction or CT myelography with simple technical modifications.

Background and purpose: Large-core acute ischemic stroke caused by large-vessel occlusion (LVO) is associated with high rates of disability despite mechanical thrombectomy. Prolonged venous transit (PVT), a marker of impaired venous drainage on CTP, has emerged as a potential prognostic indicator, but its role in large-core acute ischemic stroke (AIS)-LVO remains unclear. We aimed to test the hypothesis that PVT is independently associated with unfavorable functional outcomes in patients with large-core AIS-LVO.

Materials and methods: We conducted a retrospective cohort study using data from consecutive patients with AIS-LVO and large ischemic core volumes (ASPECTS <6 or relative CBF (rCBF)<30% volume ≥50 mL; per the SELECT-2 trial definition) between September 1, 2016, and September 2, 2024. PVT was assessed on pretreatment CTP based on qualitative time-to-maximum maps and was defined as time-to-maximum ≥10 seconds in the superior sagittal sinus or torcula. The primary outcome was unfavorable functional recovery at 90 days, defined as an mRS score of 4-6.

Results: One hundred patients met the inclusion criteria, and 41 (41%) had PVT. Unfavorable functional outcomes were more frequent in the PVT+ group (59% versus 37%; P = .036). Multivariable analysis confirmed that PVT was independently associated with unfavorable outcomes (adjusted OR, 4.07; 95% CI, 1.15-14.4; P = .03), even after accounting for penumbra size (time-to-maximum = >6s) and large-core volumes (rCBF <30%). Other predictors included older age (adjusted OR, 1.07; 95% CI, 1.02-1.11; P = .003), higher admission NIHSS (adjusted OR, 1.16; 95% CI, 1.05-1.29; P = .005), and larger rCBF <30% volume (adjusted OR, 1.02; 95% CI, 1.00-1.04; P = .032).

Conclusions: PVT is independently associated with unfavorable outcomes in patients with large core AIS-LVO. These findings suggest that PVT may serve as a prognostic marker, warranting further investigation and validation in larger prospective studies to guide treatment decisions in this high-risk population.

Background and purpose: Evaluation of polar phase signals on SWI has shown success in differentiating hemorrhage from calcification, particularly in subcentimeter spherical foci located in the brain. However, aliasing of phase signals near the center of larger susceptibility lesions presents a challenge in accurately classifying lesions with signal drop-out and blooming on SWI. We investigated the use of central halo, in addition to the polar signals, to broaden the use of SWI phase images in classifying lesions with a wider range of locations, sizes, and shapes.

Materials and methods: This retrospective study included 50 consecutive cases of patients who underwent MRI with SWI of the brain. Phase signals from the 2 polar regions and the central halo were evaluated. Susceptibility foci of all sizes, shapes, and locations were included, except for the basal ganglia calcifications. CT images were used as the gold standard for differentiating hemorrhages from calcifications. Appropriate statistical analyses were performed.

Results: The study cohort included 22 males and 28 females aged 2-90 years (mean age: 61.19 ± 21.13 years). SWI identified 406 hemorrhages: 305 intraparenchymal, 45 subdural, 22 subarachnoid, 15 intraventricular, and 19 cortical vein thromboses. There were 202 calcifications observed on SWI: 24 intraparenchymal, 41 pineal, 83 choroid plexus, 18 dural, and 36 arachnoid granulations. Hemorrhage sizes ranged from 1.5-145.2 mm (mean: 11.5 ± 15.81 mm), while calcifications ranged from 1.5-71.9 mm (mean: 8.16 ± 7.13 mm). Hemorrhagic lesions were round (300), linear (75), or irregular (31), while calcifications were round (139), linear (95), or irregular (1). Sensitivity and specificity for hemorrhages were 99.5% (95% CI, 98.23-99.4) and 100% (95% CI, 98.06-100), respectively. For calcifications, sensitivity was 84.26% (95% CI, 78.96-88.67) and specificity was 95.42% (95% CI, 90.30-98.30). The area under the curve was ≥0.97 for all 3 phase sectors in hemorrhages and ≥0.93 for the caudal and halo regions in calcifications.

Conclusions: Phase signals of SWI, analyzed across both poles and the central halo, can successfully distinguish most intracranial hemorrhages and calcifications, regardless of their size, shape, or location.

Aim/objectives/background: This practice parameter was revised collaboratively by the American College of Radiology (ACR), the American Society of Neuroradiology (ASNR), and the Society for Pediatric Radiology (SPR). The practice parameter has been updated to reflect current performance of CT angiography of the head and neck with the inclusion of newly-available information since the last revision.

Methods: This practice parameter was developed according to the process described under the heading The Process for Developing ACR Practice Parameters and Technical Standards on the ACR website (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters - Neuroradiology of the ACR Commission on Neuroradiology and the Committee on Practice Parameters - Pediatric Radiology of the ACR Commission on Pediatric Radiology in collaboration with the ASNR, and the SPR.

Results: CTA is a widely-used modality in neuroradiology, and is critically important for diagnosis and monitoring of numerous conditions. This updated practice parameter provides information on indications, patient preparation, equipment specifications, examination performance, and interpretation of head and neck CTA in current practice.

Conclusions: This practice parameter can be used to establish or modify a head and neck CTA protocol based on current evidence and recommendations.

Background and purpose: The mylohyoid muscle is commonly considered a continuous muscular sling, but it is frequently discontinuous, forming mylohyoid boutonnières (MHBs) that can contain salivary tissue, fat, blood vessels, or lymph nodes. While some studies have explored MHBs in cadavers and through CT imaging, the prevalence of them on MRI remains largely unexplored. This study aims to assess the prevalence, age dependence, anatomic distribution, and content of MHBs as visualized on MRI.

Materials and methods: A retrospective review of MRI scans of the head and neck from 294 patients between 2016 and 2020 was conducted. MR images were analyzed for the presence, location, and contents of MHBs. Interrater agreement from the 3 independent readers with different levels of experience and statistical analysis were performed to assess consistency across readers.

Results: MHBs were identified in 50.7% of individuals, with bilateral deficiencies occurring in 45.6% of cases. Most defects were located in the anterior (45.6%) and middle (51.0%) one-third of the mylohyoid muscle. The herniated content consisted predominantly of salivary tissue (69.3%), followed by fat (15.9%), and blood vessels (14.2%). No significant association was found between MHB prevalence and age. There was a high level of interrater agreement among all 3 raters regarding the presence, side, location, and content of the MHB, with no statistically significant discrepancies observed across the assessed parameters.

Conclusions: An MHB is a true and common anatomic variant, with a prevalence of 50.7% in this study, and most defects are bilateral. MRI provides high soft tissue contrast, which is beneficial for evaluating oral cavity anatomy, while CT may have higher sensitivity for small bony or soft tissue defects due to its superior spatial resolution. This knowledge aids in preventing diagnostic errors when evaluating oral cavity lesions, minimizing the need for unnecessary invasive procedures.