FLAIR hyperintensity in the subarachnoid space: Main differentials.

The fluid-attenuated inversion recovery (FLAIR) sequence forms part of the vast majority of current diagnostic protocols for brain MRI. This sequence enables the suppression of the signal from cerebrospinal fluid, facilitating the detection of disease involving the subarachnoid space. The causes of hyperintensity in the arachnoid space in this sequence can be divided into two main categories: hyperintensity due to disease and hyperintensity due to artifacts. Hyperintensity due to tumors, inflammation, vascular disease, or hypercellularity of the cerebrospinal fluid or hematic contents is well known. However, numerous other non-pathological conditions, mainly due to artifacts, that are also associated with this finding are a potential source of diagnostic errors.

The role of preoperative MRI in endoscopic transnasal transsphenoidal hypophysectomy of pituitary adenoma.

BACKGROUND: The trans-sphenoidal approach, commonly used for removing pituitary adenomas, has become a widely accepted and successful method. In recent years, the endoscopic trans-sphenoidal technique has emerged as a minimally invasive surgical approach for pituitary adenoma removal. The majority of pituitary adenomas exhibit a soft consistency and can be successfully extracted with aspiration and curettage using the trans-sphenoidal approach. However, a subset of around 5-15% of these adenomas possess a solid and fibrous texture. The occurrence of firm and fibrous adenomas is relatively common; unfortunately, there are no reliable predictors to identify them preoperatively. OBJECTIVES: The ability to forecast the reliability of magnetic resonance imaging (MRI) holds promise for improving prior preparation and impacts the extent of resection. DESIGN: A cross-sectional analysis of the investigation of magnetic resonance imaging (MRI) in relation to cancer histology was performed on 68 patients who had endoscopic trans-nasal excision for nonfunctional adenomas. MATERIALS AND METHODS: The determination of an intensity ratio was performed by employing quantitative estimates of MRI signal intensity obtained from both the adenoma and pons. During the surgical procedure, a series of sequential-graded procedures were used for the removal of tumours with varying consistencies. Softer tumours were addressed using the Suction technique (R1), while tumours of intermediate consistency were treated using curettes (R2). In order to evaluate the fibrotic content of firmer tumours, the utilization of Cavitron Ultrasound Surgical Aspirator (CUSA), and/or other micro-instruments (R3) was employed, with the histologic collagen fraction being quantified. In order to investigate and analyse the data, a statistical analysis was conducted. A predictive relationship between resection category and both intensity ratio, and collagen percentage was noted. The primary objective of this study was to determine the appropriate cutoff criteria for clinical utilization, as well as to investigate the association between intensity ratios and collagen percentage. RESULTS: Tumors with ratios ≤ 1.6 on the T2-weighted image and collagen content > 5.3% required more meticulous and sharp dissection for resection. CONCLUSIONS: The utilization of MRI analysis may offer some assistance, but not conclusive, in the prediction of tumour consistency.

Hiperintensidad en secuencia FLAIR del LCR en el espacio subaracnoideo: diagnósticos diferenciales / FLAIR hyperintensity in the subarachnoid space: Main Differentials

La secuencia fluid attenuated inversion recovery (FLAIR) forma parte hoy en día de la gran mayoría de protocolos diagnósticos de RM cerebral. Esta secuencia de inversión-recuperación permite una supresión de la señal del líquido cefalorraquídeo, lo que facilita la detección de enfermedad que afecta al espacio subaracnoideo. Las causas de hiperintensidad del líquido cefalorraquídeo en esta secuencia pueden subdividirse en 2grandes grupos, las patológicas y las debidas a artefactos. Son bien conocidas la etiología tumoral, la inflamatoria, la vascular o las debidas a hipercelularidad del líquido cefalorraquídeo o a ocupación por contenido hemático. Sin embargo, existen numerosas condiciones no patológicas, principalmente debidas a artefactos, que se relacionan con este hallazgo constituyendo una potencial fuente de errores diagnósticos.(AU)

The fluid-attenuated inversion recovery (FLAIR) sequence forms part of the vast majority of current diagnostic protocols for brain MRI. This sequence enables the suppression of the signal from cerebrospinal fluid, facilitating the detection of disease involving the subarachnoid space. The causes of hyperintensity in the arachnoid space in this sequence can be divided into two main categories: hyperintensity due to disease and hyperintensity due to artifacts. Hyperintensity due to tumors, inflammation, vascular disease, or hypercellularity of the cerebrospinal fluid or hematic contents is well known. However, numerous other non-pathological conditions, mainly due to artifacts, that are also associated with this finding are a potential source of diagnostic errors.(AU)

Comparison between 3D-FLAIR and 3D-real IR MRI sequences with visual classification method in the imaging of endolymphatic hydrops in Meniere's disease.

BACKGROUND: Clinically, the evidence of endolymphatic hydrops (EH) in Meniere's disease (MD) primarily relies on audiological examinations, such as glycerol tests and electrocochleography, to suggest the presence of EH indirectly. However, these techniques lack sensitivity and specificity, and they do not sufficiently assess the degree of EH. This study aims to explore the application of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and three-dimensional real inversion recovery (3D-real IR) sequence imaging of EH in MD and to assess the image quality and grading of EH. METHODS: The study included 50 patients with definite MD. The 3D-FLAIR and 3D-real IR sequence images were performed 24 h after bilateral intratympanic injection of gadolinium. The image quality of both sequences was reviewed by two experienced radiologists. The vestibular and cochlear EH grades of both sequences were reviewed by two experienced otologists using a visual grading method. The Cohen's kappa and Pearson tests were used to analyze the data. RESULTS: The reliability of image quality between the two radiologists was excellent (0.7 < kappa < 0.9). There were significant statistical differences in the image quality between the 3D-real IR and 3D-FLAIR sequences (p = 0.023 and p = 0.035, respectively). The reliability for the grading of vestibular and cochlear EH between the two otologists was excellent (0.7 < kappa < 0.9). The 3D-real IR sequence detected more severe hydrops than did the 3D-FLAIR sequence (p < 05). CONCLUSION: The image quality of the 3D-real IR sequence is better than that of the 3D-FLAIR sequence, and there are differences in the vestibular and cochlear EH grades of both sequences. The sensitivity of the 3D-real IR sequence in the cochlea is higher. The method of visual grading can be applied to both technologies when combined with 3D-real IR.

Imaging of facial neuritis using T2-weighted gradient-echo fast imaging employing steady-state acquisition after gadolinium injection.

BACKGROUND: MRI is the modality of choice for the imaging of facial neuritis. Previously, gadolinium-enhanced T1-weighted imaging of the petrous bone, then FLAIR sequences were thought to be most informative for acute facial neuritis imaging. The aim of this study is to evaluate the value of contrast-enhanced T2-weighted sequence for the diagnosis of acute facial neuritis and compare it to contrast-enhanced T1-weighted and FLAIR sequences. METHODS: We included 50 patients with an acute unilateral idiopathic peripheral facial neuritis. An MRI (3 T) with three sequences was performed (T1-weighted, T2-weighted and FLAIR), all acquired after intravenous contrast-media injection. RESULTS: The contrast-enhanced T2-weighted sequence appeared to be the most accurate one for the diagnosis of acute facial neuritis (Se 94%, Sp 100%, accuracy 98.2%, p < 0.001), with a pathological facial nerve strongly (grade 2-3) enhancing and a homogenous enhancement along the course of the entire facial nerve. Contrast-enhanced T1-weighted (Se 80%, Sp 100%, accuracy 94.1%) and FLAIR sequences (92%, Sp 88%, accuracy 90%, p < 0.001) showed lower accuracy. On T1-weighted sequence, a strong enhancement (blurred margins) of the canalicular segment was observed in 80% of the cases when it was never observed in normal nerves. CONCLUSION: A strong (= iso to hyperintense to the petrous fat signal) and diffuse (all segments) enhancement of the facial nerve on T2-weighted steady-state free precession sequence is a sensitive and specific sign for the diagnosis of acute idiopathic facial neuritis, and appears superior to T1WI and FLAIR sequences.

Value of MRI enhanced FLAIR sequence examination combined with CSF TNF-α detection in the early diagnosis of neonatal purulent meningitis.

This study aimed to investigate the value of MRI enhanced fluid-attenuated inversion recovery (FLAIR) combined with TNF-α in cerebrospinal fluid in the diagnosis of neonatal purulent meningitis. Fifty neonates with purulent meningitis were randomly selected in the purulency group, 50 patients with viral meningitis (VM) in the virus group and 50 neonates without purulent meningitis in the no meningitis group. All neonates were selected from April 2015 to May 2018 in Women and Children's Hospital (Linyi, China). Clinical baseline data of the three groups were compared, and logistic regression analysis was conducted to analyze the risk factors of the disease. The risk factors of neonatal purulent meningitis include white bold cell count, TNF-α, encephaledema, encephaledema combined with abnormal EEG, erythrocyte sedimentation rate and FLAIR sequential apparent diffusion coefficient (ADC). TNF-α in cerebrospinal fluid combined with FLAIR sequential ADC obtained higher sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy and AUC than single TNF-α in cerebrospinal fluid examination or single FLAIR sequence. MRI enhanced FLAIR sequence scan combined with TNF-α in cerebrospinal fluid has the highest rate in early diagnosis of neonatal purulent meningitis, and it is worthy of clinical promotion.