Neuroradiology最新文献

Background and purpose: Quantitative T1 mapping can be an essential tool for assessing tissue injury in multiple sclerosis (MS). We introduce T1-REQUIRE, a method that converts a single high-resolution anatomical 3D T1-weighted Turbo Field Echo (3DT1TFE) scan into a parametric T1 map that could be used for quantitative assessment of tissue damage. We present the accuracy and feasibility of this method in MS.

Methods: 14 subjects with relapsing-remitting MS and 10 healthy subjects were examined. T1 maps were generated from 3DT1TFE images using T1-REQUIRE, which estimates T1 values using MR signal equations and internal tissue reference T1 values. Estimated T1 of lesions, white, and gray matter regions were compared with reference Inversion-Recovery Fast Field Echo T1 values and analyzed via correlation and Bland-Altman (BA) statistics.

Results: 159 T1-weighted (T1W) hypointense MS lesions and 288 gray matter regions were examined. T1 values for MS lesions showed a Pearson's correlation of r = 0.81 (p < 0.000), R² = 0.65, and Bias = 4.18%. BA statistics showed a mean difference of -53.95 ms and limits of agreement (LOA) of -344.20 and 236.30 ms. Non-lesional normal-appearing white matter had a correlation coefficient of r = 0.82 (p < 0.000), R² = 0.67, Bias = 8.78%, mean difference of 73.87 ms, and LOA of -55.67 and 203.41 ms.

Conclusions: We demonstrate the feasibility of retroactively derived high-resolution T1 maps from routinely acquired anatomical images, which could be used to quantify tissue pathology in MS. The results of this study will set the stage for testing this method in larger clinical studies for examining MS disease activity and progression.

Introduction: Canavan disease (CD) is a rare autosomal recessive neurodegenerative disorder caused by a deficiency of aspartoacylase A, an enzyme that degrades N-acetylaspartate (NAA). The disease is characterized by progressive white matter degeneration, leading to intellectual disability, seizures, and death. This retrospective study aims to describe the full spectrum of magnetic resonance imaging (MRI) findings in a large case series of CD patients.

Materials and methods: MRI findings in 18 patients with confirmed CD were investigated, and the full spectrum of brain abnormalities was compared with the existing literature to provide new insights regarding the brain MRI findings in these patients. All the cases were proven based on genetic study or NAA evaluation in urine or brain.

Results: Imaging analysis showed involvement of the deep and subcortical white matter as well as the globus pallidus in all cases, with sparing of the putamen, caudate, and claustrum. The study provides updates on the imaging characteristics of CD and validates some underreported findings such as the involvement of the lateral thalamus with sparing of the pulvinar, involvement of the internal capsules and corpus callosum, and cystic formation during disease progression.

Conclusion: To our knowledge, this is one of the largest case series of patients with CD which includes a detailed description of the brain MRI findings. The study confirmed many of the previously reported MRI findings but also identified abnormalities that were previously rarely or not described. We speculate that areas of ongoing myelination are particularly vulnerable to changes in CD.

Background & purpose: Around 5% of dementia patients have a treatable cause. To estimate the prevalence of two rare diseases, in which the treatable cause is at the spinal level.

Methods: A radiology information system was searched using the terms CT myelography and the operation and classification system (OPS) code 3-241. The clinical charts of these patients were reviewed to identify patients with a significant cognitive decline.

Results: Among 205 patients with spontaneous intracranial hypotension (SIH) and proven CSF leaks we identified five patients with a so-called frontotemporal brain sagging syndrome: Four of those had CSF venous fistulas and significantly improved by occluding them either by surgery or transvenous embolization. Another 11 patients had infratentorial hemosiderosis and hearing problems and ataxia as guiding symptoms. Some cognitive decline was present in at least two of them. Ten patients had ventral dural tears in the thoracic spine and one patient a lateral dural tear at C2/3 respectively. Eight patients showed some improvement after surgery.

Discussion: It is mandatory to study the (thoracic) spine in cognitively impaired patients with brain sagging and/ or infratentorial hemosiderosis on MRI. We propose the term spinal dementia to draw attention to this region, which in turn is evaluated with dynamic digital subtraction and CT myelography.

Purpose: This study aimed to assess the role of Diffusion-Weighted Imaging (DWI) in routine pituitary Magnetic Resonance Imaging (MRI) protocols for distinguishing sellar and parasellar tumors, addressing the lack of clear guidelines in contemporary literature.

Methods: A retrospective analysis of 242 pituitary MRI scans with DWI sequences was conducted in a single-center study using a 1.5 T scanner and standard DWI sequence parameters. Measurements of both absolute and relative mean apparent diffusion coefficient (ADC) values, along with minimal ADC values within tumors, were performed. The adopted region of interest (ROI) based method used for these measurements was validated.

Results: Invasive pituitary adenomas exhibited significantly lower min ADC and min rADC than meningiomas, with optimal cut-off points of 0.64 (sensitivity 73%, specificity 82%) and 0.78 (sensitivity 73%, specificity 89%), respectively. Post-hemorrhagic pituitary adenomas demonstrated lower ADC values than adamantinomatous craniopharyngiomas, with an AUC of 0.893 for min rADC = 1.07, and Rathke's Cleft Cysts with mucous content, AUC 0.8 for min rADC = 1.01. Specific differentiation with high sensitivity and specificity based on diffusion parameters was observed for these tumor groups. Cystic pituitary non-functional adenomas obtained significantly lower ADC values compared to the adamantinomatous type of craniopharyngiomas and serous Rathke's Cleft Cysts (AUC up to 0.942).

Conclusions: The study concludes that integrating DWI into routine pituitary MRI protocols enhances diagnostic accuracy in distinguishing sellar and parasellar tumors. The short scan time of one minute makes DWI a valuable and precise tool, supporting its recommendation as a standard component of pituitary MRI examinations.

Background: Brain vascular pathology is an important comorbidity in Alzheimer's disease (AD), with white matter damage independently predicting cognitive impairment. However, it is still unknown how vascular pathology differentially impacts primary age-related tauopathy (PART) compared to AD. Therefore, our objectives were to compare the brain microangiopathic burden in patients with PART and AD, evaluated by MRI, while assessing its relation with neuropathological findings, patterns of brain atrophy and degree of clinical impairment.

Methods: Clinical information, brain MRI (T1 and T2-FLAIR) and neuropathological data were obtained from the National Alzheimer's Coordinating Centre ongoing study, with a total sample of 167 patients identified, that were divided according to the presence of neuritic plaques in Consortium to Establish a Registry for Alzheimer's disease (CERAD) 0 to 3. Microangiopathic burden and brain atrophy were evaluated by two certified neuroradiologists, using, respectively, the Fazekas score and previously validated visual rating scales to assess brain regional atrophy.

Results: Significant correlations were found between the Fazekas score and atrophy in the fronto-insular and medial temporal regions on both groups, with PART showing overall stronger positive correlations than in AD, especially in the fronto-insular region. For this specific cohort, no significant correlations were found between the Fazekas score and the degree of clinical impairment.

Conclusion: Our results show that PART presents different pathological consequences at the brain microvascular level compared with AD and further supports PART as an independent pathological entity from AD.

Purpose: The time-intensive nature of acquiring 3D T1-weighted MRI and analyzing brain volumetry limits quantitative evaluation of brain atrophy. We explore the feasibility and reliability of deep learning-based accelerated MRI scans for brain volumetry.

Methods: This retrospective study collected 3D T1-weighted data using 3T from 42 participants for the simulated acceleration dataset and 48 for the validation dataset. The simulated acceleration dataset consists of three sets at different simulated acceleration levels (Simul-Accel) corresponding to level 1 (65% undersampling), 2 (70%), and 3 (75%). These images were then subjected to deep learning-based reconstruction (Simul-Accel-DL). Conventional images (Conv) without acceleration and DL were set as the reference. In the validation dataset, DICOM images were collected from Conv and accelerated scan with DL-based reconstruction (Accel-DL). The image quality of Simul-Accel-DL was evaluated using quantitative error metrics. Volumetric measurements were evaluated using intraclass correlation coefficients (ICCs) and linear regression analysis in both datasets. The volumes were estimated by two software, NeuroQuant and DeepBrain.

Results: Simul-Accel-DL across all acceleration levels revealed comparable or better error metrics than Simul-Accel. In the simulated acceleration dataset, ICCs between Conv and Simul-Accel-DL in all ROIs exceeded 0.90 for volumes and 0.77 for normative percentiles at all acceleration levels. In the validation dataset, ICCs for volumes > 0.96, ICCs for normative percentiles > 0.89, and R² > 0.93 at all ROIs except pallidum demonstrated good agreement in both software.

Conclusion: DL-based reconstruction achieves clinical feasibility of 3D T1 brain volumetric MRI by up to 75% acceleration relative to full-sampled acquisition.

Purpose: This study investigates the morphometric changes in the brains of patients with frontal focal cortical dysplasia (FCD) Type II, distinguishing between right and left FCD, using voxel-based morphometry (VBM), surface-based morphometry (SBM), and subcortical shape analysis.

Methods: The study included 53 patients with frontal lobe FCD Type II (28 left-sided, 25 right-sided) and 66 age- and gender-matched healthy controls. VBM and SBM analyses were conducted using Computational Anatomy Toolbox 12.8 (CAT12.8) and Statistical Parametric Mapping 12 (SPM12). Subcortical structures were segmented using FSL-FIRST. Statistical analyses were performed using non-parametric tests, with a significance threshold of p < 0.05.

Results: VBM revealed increased gray matter volume in the bilateral ventral diencephalon, left putamen, and left thalamus in the left FCD group. SBM indicated reduced sulcal depth in the right precentral, postcentral, and caudal middle frontal gyrus in the right FCD group. Subcortical shape analysis showed internal deformation in the left hippocampus and external deformation in bilateral putamen in the left FCD group, and external deformation in the left caudate nucleus, left putamen, and right amygdala in the right FCD group.

Conclusion: Morphometric changes in frontal FCD Type II patients vary depending on the hemisphere. Right FCD Type II is associated with sulcal shallowing and external deformation in contralateral subcortical structures, while left FCD Type II shows internal and external deformations in the hippocampus and putamen, respectively, along with increased gray matter volume in the basal ganglia. These findings highlight the need for hemisphere-specific analyses in epilepsy research.

Objective

To explore the factors affecting the prognosis of patients with acute posterior circulation large vessel occlusion cerebral infarction (PCO) after mechanical thrombectomy.

Method

A retrospective study was conducted on a total of 58 patients who received thrombectomy and presented within 24 h of onset with PCO from 31 September 2020 to 31 December 2022. They were divided into two groups based on a 90-day mRS score(The mRS score of 0–3 was defined as a good prognosis, and 4–6 was defined as a poor prognosis).A univariate analysis was conducted on baseline data such as age and patient past medical history, as well as extended cerebral infarction thrombolysis grade (eTICI grade) and incidence of symptomatic intracranial hemorrhage (sICH) after surgery, for the groups with good prognosis and poor prognosis. Factors affecting the 90-day prognosis of patients were also analyzed in subgroups.

Results

The preoperative National Institutes of Health Stroke Scale (NIHSS score)[21(12–35) vs 35(35–35)], postoperative 24-h NIHSS score[13(8–22) vs 35(35–35)], computed tomography (CT)[9(9–10) vs 6.5(6–7.75)] and computed tomography (CTP) brain blood volume (CBV)[9(8–10) vs 4(2–7.75)], cerebral blood flow (CBF)[7(4.5–9) vs 2(1–4)], time to peak (Tmax) [1(0.5–4) vs 0(0–1.75)] imaging of the posterior circulation Alberta stroke project early CT score (pc-ASPECTS score), Different locations of vascular occlusion, time from femoral artery puncture to vascular recanalization(64.96 ± 33.47 vs 92.68 ± 53.17). The differences in the conversion rate of postoperative intracranial hemorrhage(0 vs 16.1%) and the incidence of sICH(0 vs 12.9%) were statistically significant (P < 0.05). The subgroup analysis showed that vascular occlusion site, preoperative CBV pc-ASPECTS scores, and postoperative sICH occurrence were related to the 90-day prognosis of patients, and the differences were statistically significant (P < 0.05).

Conclusions

Some factors that can affect the prognosis of mechanical thrombectomy in patients with acute posterior circulation large vessel occlusion cerebral infarction. Preoperative clinical symptoms and imaging evaluation have certain evaluation values for prognosis.

Purpose

The aims of this study are to explore the apparent diffusion coefficient (ADC)-dependent thresholds for time to reperfusion in reversible lesions following mechanical thrombectomy for acute ischemic stroke, and to investigate the associated risks of hemorrhagic transformation.

Methods

We conducted a retrospective case-control study, enrolling patients with large-vessel occlusion who underwent mechanical thrombectomy in Otaru General Hospital from 2016 to 2021. Reversible lesions were identified using volumetric ADC data, and the mean time from image to reperfusion (TIR) in each ADC range was compared between groups with and without reversible lesions, as well as those with and without parenchymal hematoma. The Wilcoxon rank sum test and chi-square test were used for comparison between two groups, and receiver operating characteristic curves were created to determine optimal thresholds.

Results

Seventy-five patients were included and 581 volumetric data were obtained. The mean TIR in the group with reversible lesions was shorter than in that without, and time thresholds were 131, 123 and 112 min for ADC values > 540 × 10⁻⁶, 500–540 × 10⁻⁶ and 440–500 × 10⁻⁶ mm²/s, respectively. Furthermore, in patients with parenchymal hematoma, the mean TIR was significantly longer, and the average ADC value was significantly lower than those without hematoma.

Conclusion

The time thresholds for the irreversible ischemic core may vary depending on the ADC value, and they may be shorter when the ADC value is lower. Moreover, both the low ADC value and the late reperfusion might be associated with an increased risk of parenchymal hematoma.

Purpose

This study aims to analyze the imaging features of isolated congenital middle ear malformation (CMEM) on high-resolution computed tomography (HRCT).

Methods

We retrospectively collected patients with surgically confirmed diagnosis of isolated CMEM in our hospital between January 2018 and June 2023. All patients underwent HRCT before surgery. The preoperative imaging findings were analyzed by neuroradiologists with full knowledge of the intraoperative findings.

Results

37 patients were included in this study, including 25 males and 12 females, with a median age of 16 years. A total of 44 ears underwent surgery. The most commonly affected structures were incudostapedial joint, incus long process, and stapes superstructure, followed by stapes footplate, oval window, incudomalleolar join, tympanic segment of the facial nerve canal, incus body, incus short process and malleus. All incus defect/hypoplasia/malposition, stapes superstructure deformity, malleus deformity, incudostapedial joint discontinuity, and facial nerve canal malposition/abnormal bifurcation could be observed on HRCT. Additionally, 96.0% of stapes superstructure defect, 85.7% of oval window atresia, and 41.7% of incudomalleolar joint fusion, could be visualized on HRCT. HRCT could not show ossicular soft tissue pseudo-connection and stapes footplate fixation.

Conclusions

Preoperative HRCT is an important tool for diagnosing isolated CMEM. The advantages of HRCT lie in its ability to detect ossicular defects/deformities, incudostapedial joint discontinuity, oval window atresia, and facial nerve abnormalities. However, it has a low detection rate for incudomalleolar joint fusion and cannot show ossicular soft tissue pseudo-connection and stapes footplate fixation.