AJNR. American journal of neuroradiology最新文献

Background: Prolonged venous transit (PVT) is an imaging marker that assesses venous outflow (VO) on perfusion imaging time to maximum (T_max) maps. PVT presence (PVT+) is associated with 90-day mortality and poor functional recovery in patients with anterior circulation acute ischemic stroke caused by large vessel occlusion (AIS-LVO) who underwent endovascular thrombectomy (EVT). PVT absence (PVT-) correlates with excellent outcomes. We determined the association between PVT and functional outcomes post-EVT in patients with acute basilar artery occlusions (BAO).

Methods: In this retrospective study, we included patients from nine academic medical centers. We selected patients who had pre-thrombectomy CT or MR perfusion imaging and assessment of 90-day Modified Rankin Scale (mRS). PVT+ in the posterior circulation was defined as a T_max≥10 seconds delay in the torcula, left transverse sinus, and/or right transverse sinus. PVT- was defined as the absence of this marker. The primary outcome was excellent functional outcome at 90 days as defined by an mRS 0-1.

Results: Ninety-seven patients with acute BAO were scored for PVT. 58 patients (60%) had PVT+ and 39 (40%) had PVT-. PVT- patients were younger (median age 60 years [IQR 50-70] versus 68 years [IQR 62-79] in PVT+; p=0.01), more likely to present with a wake-up stroke (44% versus 16% in PVT+; p=0.04), and more likely to have excellent functional outcomes (44% versus 22% in PVT+; p=0.03). In an adjusted multivariable regression analysis, lower presentation NIHSS was associated with excellent functional outcomes (OR: 0.89; 95% CI: 0.82-0.96, p=0.002). There was also a significant interaction between age and PVT, where older patients with PVT+ experienced worse outcomes (p=0.04).

Conclusions: In patients with acute BAO who underwent EVT, lower presentation NIHSS was associated with excellent 90-day functional outcomes, and PVT+ was associated with worse outcomes in older patients.

Tandem occlusions represent one of the most challenging scenarios in endovascular treatment of acute ischemic stroke.^1-4 Management of extracranial occlusion is technically demanding, especially when located at the level of the brachiocephalic trunk. We report 2 cases of tandem lesions due to a brachiocephalic trunk. In the first, a distal hemodynamic occlusion was treated with a side-by-side Wallstent (Boston Scientific), in the common carotid artery and subclavian artery, after unsuccessful thrombectomy using a double stent and a 0.88-inch-long sheath. In the second, a tandem lesion with M1 occlusion and stenosis at the origin of the brachiocephalic trunk was approached retrogradely to recanalize the M1, followed by a combined antegrade-retrograde strategy to treat the trunk. These cases illustrate the need for technical flexibility and adaptation, often requiring devices from peripheral or cardiology fields. Our experience underscores the importance of tailored endovascular strategies in managing complex extracranial occlusions associated with tandem lesions.

Background and purpose: Congenital cytomegalovirus (cCMV) is the leading infectious cause of birth defects in the United States; its spectrum of MRI findings is broad, with cerebellar abnormalities scarcely reported in the literature. We aim to describe the neuroimaging spectrum of cerebellar anomalies and malformations in patients with cCMV infection and their associations with other typical cCMV findings in prenatal and postnatal brain MRI.

Methods: We conducted a single-center retrospective observational study at a quaternary children's hospital. Included patients had fetal and/or postnatal brain MRI and confirmed congenital cCMV infection. Age-matched controls were also analyzed. Two neuroradiologists evaluated cerebellar morphology on fetal and postnatal brain MRIs; one determined cerebellar size and documented other common cCMV imaging features. Statistical analyses included paired t-tests, Cohen's d, McNemar's, and Chi-square tests, with inter-rater reliability assessed by Cohen's Kappa and Phi coefficient.

Results: Seventy-two MRIs (64 patients) were included from 36 CMV+ and 36 controls. In the CMV+ group, 17 MRIs (47.2%) were fetal (median gestational age: 30 weeks [IQR: 23-33.6]), and 19 (52.8%) were postnatal (median age: 4.23 months [IQR: 0.36-11.89]). Eight patients underwent both fetal and postnatal imaging. Cerebellar hemisphere and vermian dysmorphology were seen in 10 fetal MRIs (58.8%). Postnatally, the cerebellar hemispheres were abnormal in 11 (57.9%) MRIs, and the vermis in 9 (47.4%), with dysfolia/dysplasia being the most prevalent malformation (57.9% and 47.4%, respectively). Interrater reliability for identifying cerebellar abnormalities showed moderate agreement (kappa=0.665). Vermis height (p=0.02) and anteroposterior diameter (p<0.001) were smaller in CMV+ postnatal MRIs, but not in fetal studies. All cases with cerebellar abnormalities also had at least one other CMV-related finding (φ =0.581).

Conclusion: cCMV-associated cerebellar malformations are more prevalent than previously reported in the literature. Cerebellar abnormalities were nearly as frequent or more frequent than many of the typically reported cCMV features, and were always found in association with other typical imaging findings. The cerebellum requires careful evaluation in all cases of suspected cCMV.

Access to MRI remains severely limited across Africa due to the high cost, complex infrastructure, and technical expertise required to operate standard high-intensity MRI systems. This disparity contributes to diagnostic delays and poor health outcomes in low- and middle-income countries, where the burden of noncommunicable diseases and trauma is rapidly increasing. Low- and ultra-low-intensity MRI systems, operating below 0.3T, present a promising, cost-effective alternative for improving diagnostic access in resource-limited settings. This article explores the potential of these systems to bridge health care gaps by examining their benefits, such as portability, lower power consumption, and reduced maintenance requirements.

Background and purpose: Low-level light therapy (LLLT) has been shown to modulate recovery in patients with traumatic brain injury (TBI). However, the longitudinal impact of LLLT on brain metabolites has not been studied. The purpose of this study was to use MR spectroscopic imaging to assess the metabolic response of LLLT in patients with moderate TBI at acute (within 1 week), subacute (2-3 weeks), and late-subacute (3 months) recovery phases.

Materials and methods: This is a secondary analysis of a prospective single-site double-blind sham-controlled study conducted in patients with moderate TBI. Participants were randomized for LLLT and sham treatment. Three-Tesla 2D MR spectroscopic imaging was acquired. Our focus of investigation was the metabolic change in the corpus callosum (CC) and the changes in mIns/NAA, representing the combined effect of elevated neuroinflammation (mIns) and decreased neuronal/axonal health (NAA). A linear mixed-effects model was constructed to quantify the association between mIns/NAA and treatment, scan, and the interaction between treatment and scan.

Results: Thirty-four participants (18 men, age 49 ± 17 [range, 20-79]; 15 LLLT, 19 sham) were included in the final data set and were scanned at the following time points: acute (n=24), subacute (n=27), and late subacute (n=23). The mIns/NAA ratio in the CC of the sham-treated participants increased over time. Sham-treated participants revealed a significant increase in mIns/NAA from the acute to the late subacute phases (0.19; 95% CI, 0.09-0.29; P _Holm = .005). mIns/NAA stayed relatively stable in participants undergoing LLLT treatment (all P _Holm > .64). Consequently, mIns/NAA was significantly higher in the sham-treated participants compared with the LLLT-treated participants during the late subacute phase of recovery (-0.31; 95% CI, -0.50 to -0.12; P _Holm = .019).

Conclusions: Despite the small sample size, MR spectroscopic imaging indicates a metabolic response in participants treated with LLLT compared with those receiving sham treatment. This potentially suggests a neuroprotective and anti-inflammatory effect from the acute administration of LLLT in individuals with moderate TBI.

Background and purpose: Alzheimer disease (AD) is a progressive neurodegenerative disorder that predominantly affects the aging population. Anti-amyloid β (anti-Aβ) therapies, such as lecanemab, have been developed to slow disease progression. However, their use is occasionally associated with amyloid-related imaging abnormalities (ARIA), posing prominent clinical challenges. It has been shown that apolipoprotein E (APOE)-ε4 genotype is strongly associated with an increased risk of microhemorrhages in AD, but the influence of specific APOE genotypes on imaging features important for anti-Aβ therapy remains unclear. This study explores the association between APOE genotypes and key imaging biomarkers in patients being considered for lecanemab treatment.

Materials and methods: This retrospective study evaluated patients with AD who underwent APOE genotyping and were considered for lecanemab therapy. Key assessments included microhemorrhage counts, white matter hyperintensity (WMH) scores, perivascular space (PVS) evaluations, and cognitive function. Microhemorrhages were identified based on both SWI and GRE sequences in each patient. Six radiologists blinded to the patient's APOE genotype status independently conducted the imaging analyses.

Results: A total of 85 patients were included in the study with rare genotypes excluded from analysis (3 patients). Among the common genotypes, e3/e4 was the most prevalent (55%). Statistical analysis revealed significant association between APOE genotype and microhemorrhage count based on the SWI and GRE sequences (P = .007 and P = .003, respectively). The mean identified microbleed count was 1 (based on SWI) and 0.5 (based on GRE) in the same cohort of patients, with the following genotype-specific means based on SWI sequence: e3/e3 = 0.7; e3/e4 = 0.6; and e4/e4 = 2.7. No significant associations were found between APOE genotype and Montreal Cognitive Assessment, WMH or PVS scores. Post hoc power analysis showed adequate power for SWI-based microbleed detection but low power for WMH and PVS.

Conclusions: In this cohort of patients with AD being evaluated for lecanemab therapy, a significant association was identified between APOE genotype and the number of microhemorrhages with higher mean counts of microbleeds detected on SWI sequence compared with microbleeds detected on the GRE sequence of the same patients. No significant associations were found between APOE genotype and WMH, PVS, or cognitive impairment.

Background and purpose: Head and neck squamous cell carcinoma (HNSCC) represents a serious global health burden, with over 890,000 new cases annually and approximately 450,000 related deaths worldwide. Our study aims to optimize DWI sequences for the head and neck and determine reproducibility metrics values for ADC, allowing clinicians to distinguish between genuine physiologic changes and measurement errors.

Materials and methods: We optimized the head and neck DWI protocol using Qualitative Initiative Biomarker Alliance (QIBA)-recommended parameters, high 2000 b-value, Zoom-IT technology, and a polyvinylpyrrolidone phantom calibration. Twenty-six biopsy-proved patients with HNSCC underwent pretreatment "coffee-break" test-retest DWI scans on a Siemens 3T Vida MRI scanner. ADC values were extracted from 46/51 segmented tumor regions (either tumor mass or metastatic lymphadenopathy), and reproducibility measures were assessed using the within-subject coefficient of variation (wCV), repeatability coefficient, and intraclass correlation coefficient (ICC). Bland-Altman plots and correlation analyses were used to evaluate measurement precision. Both manual segmentation by 2 expert neuroradiologists and semiautomated methods of segmentation were utilized.

Results: Out of 51 identified tumor masses, 46 were included in the final analysis. The Bland-Altman plot revealed minimal bias in ADC values between test-retest scans. The calculated 5.2-5.4% wCV resulted in a repeatability coefficient of 14.4%. The ICC between test and retest measurements was 0.8-0.83, indicating good test-retest reliability. The Dice score between the 2 expert readers for all parameters indicated excellent agreement between segmentations performed by different readers, with values of 0.991 for the test measurement and 0.976 for the retest measurement.

Conclusions: Our findings support the use of an optimized DWI protocol for accurate and reproducible ADC quantification in HNSCC, which is comparable with or better than the percent repeatability coefficient derived from QIBA profiles for breast, liver, and prostate, though it is inferior to those for the brain. Further quantitative imaging biomarker Stage 2-type profile research is necessary to refine imaging parameters, improve reproducibility markers, and establish DWI as a clinical standard for evaluating HNSCC tumor recurrence.

Background and purpose: Spontaneous intracranial hypotension (SIH) is a disabling condition that is frequently underdiagnosed as a result of diagnostic challenges. Delays in diagnosis can be attributed to under-recognized MRI findings or a lack of clinical suspicion, given the wide range of symptoms. This study aims to explore the diagnostic burden of SIH by examining the number of imaging examinations and clinician visits before diagnosis.

Materials and methods: This retrospective single-institution study included 71 patients with spinal CSF leaks who had a confirmed diagnosis of CSF-venous fistula (CVF) on digital subtraction myelography (DSM). We reviewed each patient's clinical history, including the number of providers in different specialties and institutions, as well as the number and type of imaging studies performed before the positive DSM at our center. Brain MR images were scored using the Bern criteria, and clinical history, along with imaging data, were compared across Bern groups (low, intermediate, high probability).

Results: The mean patient age was 57.6 years, with most being women (65%). The mean duration of symptoms was 3.8 years, and 14.1% of patients experienced symptoms for ≥10 years before the positive DSM. The mean number of specialists seen per patient was 2.6 (SD: 2.7; range, 0-13), and 28% of patients consulted 4 or more specialists before the positive DSM. On average, each patient underwent 6 imaging studies (SD: 3.8; range: 2-22) before the DSM, including 5.3 MRIs (SD: 3.7; range: 2-22), and 2.5 brain MRIs (SD: 2.1; range: 1-11). The percentage of patients who underwent ≥7 total imaging studies was 40.8%, and 53.5% had ≥3 brain MRIs before diagnosis. Though no statistically significant differences were found in the mean number of specialists or imaging examinations between Bern score groups, a trend of increasing diagnostic burden was observed from the high to low Bern score groups.

Conclusions: Patients with spinal CSF leaks often undergo an extensive number of imaging and specialty consultations, contributing to delays in diagnosis and appropriate treatment. This study highlights the need to increase awareness among health care providers regarding the typical symptoms and imaging features of spinal CSF leaks.

Background and purpose: FLAIR hyperintense vessels (FHV), quantified using the National Institutes of Health (NIH)-FHV score (NFS), and the SWI brush sign (SBS) are MRI markers associated with hemodynamic impairment in acute ischemic stroke (AIS). We aimed to evaluate the prognostic significance of posttreatment NFS and SBS in patients with anterior circulation large-vessel occlusion (AIS-LVO), including those with successful reperfusion.

Materials and methods: We retrospectively analyzed 273 patents with AIS-LVO with in-hospital follow-up MRI. NFS and SBS were evaluated and correlated with clinical outcomes including NIHSS shift (≥4-point improvement) and hemorrhagic transformation (HT). The Spearman correlation and logistic regression were performed, adjusting for clinical covariates. Analyses were repeated in the successfully reperfused subgroup of 181 cases (modified TICI [mTICI] ≥2b).

Results: FHV and the SBS were observed posttreatment in 38% and 20% of patients, respectively. NFS and SBS were positively correlated (ρ = 0.54, P < .01). NFS inversely correlated with NIHSS shift (ρ = -0.27, P < .01) and reperfusion grade (mTICI; ρ = -0.32, P < .01). NFS was independently associated with worse NIHSS shift (OR, 0.64; P < .01) and reduced odds of HT (OR, 0.76; P < .01). Among patients with successful reperfusion, 20% of mTICI 3 cases showed FHV. In this subgroup, NFS remained predictive of poor NIHSS shift (OR, 0.57; P = .01). SBS alone was not independently associated with outcomes.

Conclusions: NFS on posttreatment MRI is a robust imaging biomarker of persistent perfusion deficits and early neurologic outcome, even after successful reperfusion. SBS may reflect complementary collateral dynamics but showed limited independent prognostic utility.