Neuroradiology最新文献

Purpose: Guillain-Barré Syndrome (GBS) is an autoimmune disorder causing acute inflammatory polyneuropathy, resulting in muscle weakness. Timely diagnosis is critical to prevent complications such as respiratory failure and long-term disability. Ultrasound imaging of peripheral nerves, specifically assessing nerve cross-sectional area (CSA), has been suggested as a diagnostic tool for GBS. This systematic review aims to evaluate the utility of nerve ultrasound in diagnosing and monitoring GBS.

Methods: A systematic review was conducted following PRISMA guidelines, searching databases including PubMed, Scopus, Web of Science, and Cochrane Library up to December 2024. Studies that used ultrasound to assess peripheral nerve size in GBS patients compared to healthy controls or other neuropathy patients were included. Statistical analysis was conducted using Review Manager 5.4 software.

Results: Out of 848 studies, 25 met the inclusion criteria, with 12 included in the meta-analysis. A total of 528 patients with GBS were included. Ultrasound revealed significant increases in the CSA of cervical, peroneal, median, ulnar, and tibial nerves in GBS patients. Specifically, cervical nerve enlargement (MD: 1.45, P = 0.0008) and peroneal nerve enlargement (Mean Difference (MD): 2.09, P < 0.00001) were notable. Subgroup analysis revealed significant enlargement of the ulnar and tibial nerves across different anatomical regions.

Conclusion: Ultrasound imaging of peripheral nerves, particularly changes in CSA, provides valuable diagnostic insight for GBS, may be helpful in early recognition and intervention. Further studies are needed to establish consistent CSA patterns and improve diagnostic accuracy across various GBS subtypes.

Introduction: Ventriculomegaly (VM) is the fetal central nervous system (CNS) anomaly most commonly represented in prenatal imaging. It is defined as a lateral ventricle of dimensions greater than or equal to 10 mm; it can be unilateral or bilateral. More generally, hydrocephalus is defined as an imbalance between brain parenchyma and cerebrospinal fluid (CSF) due to an abnormal increase of the latter within the ventricles in an almost bilateral manner. To identify ventriculomegaly and categorize its severity, the appropriate imaging and measurement methods are crucial. Clinical outcomes vary greatly because of the wide differential diagnosis. Furthermore, there is a significant chance that these causes may recur in subsequent pregnancies. Pregnancy care and counseling depend on a precise diagnosis of the underlying cause.

Materials and methods: We retrospectively reviewed our institutional fetal MR imaging database (4568 examinations) from 2005 until 2024. We focused on obstructive hydrocephalus and, according to rigorous inclusion/exclusion criteria (Table 1), we enrolled 201 cases.

Results: We analyzed isolated aqueduct stenosis (36.3%); hemorrhagic events (30.3%); rhombencephalosynapsis (7.5%); dural sinus malformation (6%); midline cysts (5.4%); diencephalic-mesencephalic junction (DMJ) dysplasia (3.5%); infectious lesions (3%); tumors (2.5%); Chiari 1 (1.5%); Walker Warburg disease (1%); not otherwise specified (3%).

Discussion: We discuss the different etiologies of obstructive hydrocephalus in our population and propose an etiology-based approach that allows the clinician and radiologist to reach the correct differential diagnosis and provide an indication for possible fetal surgery.

Conclusion: Hydrocephalus arises from embryological abnormalities or acquired insults, requiring precise neuroimaging for diagnosis and management. A thorough imaging approach aids in etiological diagnosis, surgical planning, and essential counseling.

Purpose: Herpes simplex virus 1 encephalitis (HSE) is the most common sporadic infectious encephalitis in Western countries, with a 70% mortality rate and only 9% of survivors free from neurological sequelae. While definitive diagnosis relies on cerebrospinal fluid testing, magnetic resonance imaging (MRI) plays a crucial role in identifying typical acute patterns and features. However, the imaging evolution of encephalitic lesions is not well understood. We aimed to identify and evaluate the prevalence and progression of cortical lesions, as well as the recurrence of these patterns in HSE and other encephalitic etiologies.

Methods: As a retrospective monocentric study, we included 40 patients with various etiological encephalitis from our institute. Each patient's lesions were assessed, by three experienced neuroradiologists, in the acute phase and associated with specific evolution patterns in the chronic phase.

Results: 10 out of 11 (91%) patients diagnosed with HSV-1 presented during chronic phase selective cortical liquefaction, identified as Cortical Melt Sign (CMS) (Fisher's exact p-value < 0.001). Moreover, this pattern was then correlated with acute diffusion restriction-potentially explaining CMS as a chronic imaging biomarker for HSE as a result of the acute inflammation.

Conclusion: These findings can aid in understanding the pathological mechanisms of herpetic encephalitis and guide differential diagnosis. Moreover, CMS could serve as a retrospective imaging marker in HSE.

Purpose: Hyperdense middle cerebral artery sign (HMCAS) is a phenomenon highly specific for acute ischaemic stroke (AIS) that can be found in brain non-contrast computed tomography (NCCT). Previous studies concerning its association with outcomes of patients undergoing mechanical thrombectomy (MT) are inconclusive. Our aim was to assess the relationship between HMCAS presence and long-term outcomes of AIS patients undergoing MT.

Methods: The study included anterior circulation AIS patients treated with MT in the University Hospital in [ANONYMIZED] from 2019 to 2021, in whom admission NCCT and one-year follow-up were available. The clinical, laboratory and imaging data, as well as following outcomes: the occurrence of successful recanalization [defined as modified treatment in cerebral infarction (mTICI) score 2b-3], haemorrhagic complications (ICH), 90-day and 365-day rates of mortality and good functional outcome [defined as modified Rankin Scale (mRS) score 0-2] were compared between groups of patients with and without HMCAS on initial NCCT. The association of HMCAS presence with the abovementioned outcomes was assessed using multivariate logistic regression analysis.

Results: Among 359 MT-treated patients with anterior circulation AIS, HMCAS was found in 244 (67.97%). The presence of HMCAS was independently associated with good functional outcome at 365 days (OR 1.956, 95% CI = 1.152-3.317, p = 0.013) as well as lower 90-day and 365-day mortality (OR = 0.464, 95% CI = 0.2517-0.856; p = 0.014 and OR 0.543, 95% CI: 0.313-0.940, p = 0.029, respectively).

Conclusion: The presence HMCAS on admission NCCT is associated with favourable long-term outcome in AIS patients undergoing MT.

Purpose: This study validated VParNet and nnU-Net for ventricular segmentation in pediatric hydrocephalus, a condition characterized by irregular and asymmetric ventricular shapes.

Methods: Manual segmentation of 139 MRI scans (ages range 2.6-20.3 years) was performed for the four ventricles and the aqueduct. A five-fold cross-validation was conducted for both models. VParNet was tested with its original weights and after retraining on pediatric data. nnU-Net was extended to also segment the aqueduct. Performance was evaluated using the Dice Similarity Coefficient (DSC), Intraclass Correlation Coefficient (ICC), and Minimal Detectable Change (MDC).

Results: VParNet preprocessing failed in 20.9% of cases, requiring subject exclusion. Both models showed good to excellent segmentation accuracy and reliability (DSC: 0.87-0.95; ICC: 0.81-1.0). Retraining VParNet improved DSC scores. MDC values (0.05-3.0) indicated high sensitivity for the lateral and third ventricles and acceptable sensitivity for the fourth ventricle. Aqueduct segmentation remained challenging (nnU-Net: DSC = 0.68; ICC = 0.81; MDC = 0.04).

Conclusion: All tested models performed well in pediatric hydrocephalus segmentation, with no fundamental differences in overall performance. However, nnU-Net demonstrated key advantages due to its lack of preprocessing requirements, which allow the successful handling of even the most challenging subjects. These features make it easily implementable for clinical applications, providing fast and reliable ventricular segmentation and quantification.

Purpose: This study aimed to optimize three-dimensional real inversion recovery (3D-real IR) with T2 preparation (T2Prep) protocols to improve perilymphatic enhancement (PE) and endolymphatic hydrops (EH) detection.

Methods: Fifty-three consecutive participants with unilateral Ménière's disease were prospectively recruited. All participants underwent 3D-zoomed imaging technique with parallel transmission real IR (z-3D real IR), z-3D real IR with T2Prep (tz-3D real IR), and optimized tz-3D real IR (otz-3D real IR). Overall image quality, the separation of endolymph and perilymph and EH were scored/graded and compared among three 3D real IRs respectively. The signal intensity ratio (SIR), contrast to noise ratio (CNR), and signal to noise (SNR) were quantitatively calculated and compared among three 3D real IRs respectively.

Results: Tz-3D real IR was superior to z-3D real IR in overall image quality, SIR, SNR, and CNR (P < 0.017 for all), moreover, the vestibular EH detection of tz-3D real IR sequence were inferior to z-3D real IR (P = 0.005). On otz-3D real IR images, overall image quality, endolymph visualization, and the SIR and CNR significantly increased compared to those of the tz-3D real IR sequence and z-3D real IR sequence (P < 0.017 for all). Moreover, the cochlear and vestibular EH detection of otz-3D real IR sequence were significant superior to tz-3D real IR (P = 0.008 for both).

Conclusion: The optimized otz-3D real IR sequence, incorporating T2Prep, significantly improves PE and EH detection. These enhancements highlight its potential utility in clinical settings for accurate and timely diagnosis of EH.

Background: Management of patients with persistent or worsening symptoms following traumatic brain injury (TBI) presents difficulties. MRI is usually negative in mild TBI (mTBI) and usually only shows residual quiescent disease in moderate to severe TBI (msTBI).

Objective: We hypothesize that patients with persistent symptoms from prior TBI will show findings on a divided Subtracted Inversion Recovery (dSIR) sequence that are sensitive to small changes from normal in white matter T₁.

Materials and methods: Neurologically healthy controls (n = 37) and patients with persistent symptoms following TBI (n = 29) were examined with T₂-FLAIR and dSIR sequences. T₂-FLAIR images were evaluated for minor changes and overt pathology. dSIR images were evaluated for "whiteout signs" defined as widespread, bilateral, and symmetrical high signal in white matter. Odds ratios were calculated for the association between the presence of a whiteout sign and being in the symptomatic group.

Results: Overt pathology was seen on the T₂-FLAIR images in six msTBI patients and one mTBI patient. No widespread changes were seen on the T₂-FLAIR images in the control or TBI groups. Whiteout signs were seen on the dSIR images in 25 of 29 TBI patients and in three of 37 controls. The whiteout sign was strongly associated with symptomatic TBI status, with odds ratios ≥ 14. The kappa statistic for inter-reader correlation (whiteout sign vs. no whiteout sign) was κ = 0.85.

Conclusion: The whiteout sign was strongly associated with being in the symptomatic group and is a potential biomarker for recognition of secondary changes to the brain in patients with persistent symptoms following TBI.

Background: Ependymal enhancement is an uncommon but diagnostically challenging MRI finding with a wide range of aetiologies.

Purpose: This pictorial essay presents an algorithmic approach to its differential diagnosis.

Results: We categorize the ependymal enhancement into three main etiologic groups: infectious disorders, non-infectious inflammatory disorders and tumors, highlighting specific demographic, clinical, and imaging findings that are crucial for diagnosis. We provide two diagnostic algorithms according to the patient's immune status, since it is paramount in determining the differential diagnosis. For immunosuppressed patients, the workflow focuses on the enhancement pattern (linear, band-like or nodular appearances) and the presence of concomitant intra-axial masses, directing the differential toward entities such as toxoplasmosis or lymphoma. For immunocompetent patients, the diagnostic pathway relies on clinical history and lesion characteristics to distinguish infectious, inflammatory, and neoplastic causes, further refined by the presence or absence of an intra-axial mass.

Conclusion: These diagnostic algorithms may help neuroradiologists structure the differential diagnosis and improve clinical decision-making.

Craniopharyngiomas are rare, benign tumors with a bimodal age distribution, typically found in children and older adults. They arise along the craniopharyngeal tract, often in the intra- or suprasellar regions, and may compress adjacent structures, causing diverse symptoms. Diagnosis is primarily MRI-based, revealing heterogeneous mass with cystic and solid elements. Chordoma, another rare tumor, arises from notochordal remnants, often in the sacrum or clivus, and displays distinct imaging characteristics like T2 hyperintensity and bony destruction. This report discusses a rare ectopic clival craniopharyngioma in an 11-year-old- the youngest case reported in the literature to our knowledge -extending from the sellar to the clival region. Noteworthy imaging findings included T1 hyperintensity and a downward growth pattern along the expected Rathke pouch course, helping distinguish it from chordoma.