Imaging of inner ear malformations: a primer for radiologists

In the multidisciplinary management of patients with inner ear malformations (IEMs), the correct diagnosis makes the differences in terms of clinical and surgical treatment. The complex anatomical landscape of the inner ear, comprising several small structures, makes imaging of this region particularly challenging for general radiologists. Imaging techniques are important for identifying the presence and defining the type of IEM and the cochlear nerve condition. High-resolution magnetic resonance imaging (MRI) sequences and high-resolution computed tomography (HRCT) are the mainstay imaging techniques in this area. Dedicated MRI and HRCT protocols play an important role in the diagnosis and treatment of patients with inner ear disease. The most suitable technique should be selected depending on the clinical setting. However, in cases of congenital malformation of the inner ear, these techniques should be considered complementary. Since prompt intervention has a positive impact on the treatment outcomes, early diagnosis of IEMs is very important in the management of deaf patients. This article reviews the key concepts of IEMs for clinical radiologists by focusing on recent literature updates, discusses the principal imaging findings and clinical implications for every IEM subgroup, thus providing a practical diagnostic approach

Clinical and brain imaging findings in a child with vitamin B12 deficiency

Vitamin B12 (Vit-B12) deficiency is a rare and treatable cause of failure to thrive and delayed development in infants who are exclusively breastfed. Apart from genetic causes, it can be related to a malabsorption syndrome or when the mother follows a strict vegetarian or vegan diet, causing a low hepatic storage of Vit-B12 in the infant at birth. As the neurological symptoms are nonspecific, a brain magnetic resonance imaging (MRI) exam is usually performed to rule out primary causes of neurodevelopmental delay. Findings related to brain atrophy are usually observed. A favorable response is achieved with Vit-B12 therapy, and neurological symptoms dramatically improve within a few days after the treatment. We present the case of an infant with severe Vit-B12 deficiency, exclusively breastfed by his young vegan mother, and whose clinical symptoms together with MRI findings improved after treatment. Brain atrophy recovery after Vit-B12 therapy has been seldom documented

Conventional MRI-Derived Biomarkers of Adult-Type Diffuse Glioma Molecular Subtypes: A Comprehensive Review

The introduction of molecular criteria into the classification of diffuse gliomas has added interesting practical implications to glioma management. This has created a new clinical need for correlating imaging characteristics with glioma genotypes, also known as radiogenomics or imaging genomics. Although many studies have primarily focused on the use of advanced magnetic resonance imaging (MRI) techniques for radiogenomics purposes, conventional MRI sequences remain the reference point in the study and characterization of brain tumors. A summary of the conventional imaging features of glioma molecular subtypes should be useful as a tool for daily diagnostic brain tumor management. Hence, this article aims to summarize the conventional MRI features of glioma molecular subtypes in light of the recent literature

Diffuse Lipomatosis of Thyroid Gland

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Malignancy course of pituitary adenoma in MEN1 syndrome: Clinical-Neuroradiological signs

Pituitary carcinomas (PCa) are extremely rare, indistinguishable from pituitary adenomas on histopathological grounds and have a poor prognosis. Most PCa start as PRL or ACTH secreting tumors in males, with relapsing invasive behaviour, refractoriness to medical and radiotherapy and increasing hormonal levels. The presence of distant metastases is still required for the diagnosis of PCa. The association with genetic endocrine diseases must be taken into account, since it adds further risk of evolution towards malignancy. Intradural spinal metastases have also been reported, so a complete craniospinal MR evaluation is recommended, when clinically indicated. We report a case of PCa, associated with MEN1 syndrome, with evidence of meningeal spread to the tentorium cerebelli, clival dura and spinal drop metastases mimicking spinal nerves schwannomas

Tyrosol may prevent obesity by inhibiting adipogenesis in 3T3-L1 preadipocytes

Tyrosol (TR), a major polyphenol found in extra virgin olive oil (EVOO), exerts several antioxidant effects. However, only scarce evidences are present regarding its activity on adipocytes and obesity. This study evaluated the role of TR in adipogenesis. Murine 3T3-L1 preadipocytes were incubated with TR (300 and 500 μM), and TR administration inhibited adipogenesis by downregulation of several adipogenic factors (leptin and aP2) and transcription factors (C/EBPα, PPARγ, SREBP1c, and Glut4) and by modulation of the histone deacetylase sirtuin 1. After complete differentiation, adipocytes treated with 300 and 500 μM TR showed a reduction of 20% and 30% in lipid droplets, respectively. Intracellular triglycerides were significantly reduced after TR treatment (p < 0.05). Mature adipocytes treated with TR at 300 and 500 μM showed a marked decrease in the inflammatory state and oxidative stress as shown by the modulation of specific biomarkers (TNF, IL6, ROS, and SOD2). TR treatment also acted on the early stage of differentiation by reducing cell proliferation (~40%) and inducing cell cycle arrest during Mitotic Expansion Clonal (first 48 h of differentiation), as shown by the increase in both S1 phase and p21 protein expression. We also showed that TR induced lipolysis by activating the AMPK-ATGL-HSL pathway. In conclusion, we provided evidence that TR reduces 3T3-L1 differentiation through downregulation of adipogenic proteins, inflammation, and oxidative stress. Moreover, TR may trigger adipose tissue browning throughout the induction of the AMPK-ATGL-UCP1 pathway and, subsequently, may have promise as a potential therapeutic agent for the treatment and prevention of obesity

Brain mapping-aided supratotal resection (Sptr) of brain tumors: The role of brain connectivity

Brain gliomas require a deep knowledge of their effects on brain connectivity. Understanding the complex relationship between tumor and functional brain is the preliminary and fundamental step for the subsequent surgery. The extent of resection (EOR) is an independent variable of surgical effectiveness and it correlates with the overall survival. Until now, great efforts have been made to achieve gross total resection (GTR) as the standard of care of brain tumor patients. However, high and low-grade gliomas have an infiltrative behavior and peritumoral white matter is often infiltrated by tumoral cells. According to these evidences, many efforts have been made to push the boundary of the resection beyond the contrast-enhanced lesion core on T1w MRI, in the so called supratotal resection (SpTR). SpTR is aimed to maximize the extent of resection and thus the overall survival. SpTR of primary brain tumors is a feasible technique and its safety is improved by intraoperative neuromonitoring and advanced neuroimaging. Only transient cognitive impairments have been reported in SpTR patients compared to GTR patients. Moreover, SpTR is related to a longer overall and progression-free survival along with preserving neuro-cognitive functions and quality of life

A Semi-Unsupervised Segmentation Methodology Based on Texture Recognition for Radiomics: A Preliminary Study on Brain Tumours

Because of the intrinsic anatomic complexity of the brain structures, brain tumors have a high mortality and disability rate, and an early diagnosis is mandatory to contain damages. The commonly used biopsy is the diagnostic gold standard method, but it is invasive and, due to intratumoral heterogeneity, biopsies may lead to an incorrect result. Moreover, some tumors cannot be resectable if located in critical eloquent areas. On the other hand, medical imaging procedures can evaluate the entire tumor in a non-invasive and reproducible way. Radiomics is an emerging diagnosis technique based on quantitative medical image analyses, which makes use of data provided by non-invasive diagnosis techniques such as X-ray, computer-tomography (CT), magnetic resonance (MR), and proton emission tomography (PET). Radiomics techniques require the comprehensive analysis of huge numbers of medical images to extract a large and useful number of phenotypic features (usually called radiomics biomarkers). The goal is to explore and obtain the associations between features of tumors, diagnosis and patients’ prognoses to choose the best treatments and maximize the patient’s survival rate. Current radiomics techniques are not standardized in term of segmentation, feature extraction, and selection, moreover, the decision on suitable therapies still requires the supervision of an expert doctor. In this paper, we propose a semi-automatic methodology aimed to help the identification and segmentation of malignant tissues by using the combination of binary texture recognition, growing area algorithm, and machine learning techniques. In particular, the proposed method not only helps to better identify pathologic tissues but also permits to analyze in a fast way the huge amount of data, in Dicom format, provided by non-invasive diagnostic techniques. A preliminary experimental assessment has been conducted, considering a real MRI database of brain tumors. The method has been compared with the segmentation software’s tools “slicer 3D”. The obtained results are quite promising and demonstrate the potentialities of the proposed semi-unsupervised segmentation methodology

Lesioni secondarie

Le lesioni traumatiche cerebrali (TBI) sono classificate in primarie e in secondarie, a seconda della cronologia di comparsa e del meccanismo fisiopatologico che le genera. Le lesioni primarie \u2013 espressione fisiopatologica diretta del trau- ma cranico originario \u2013 compaiono al momento dell\u2019impatto trau- matico e vengono distinte topograficamente in intra-assiali (contu- sione cerebrale, danno assonale diffuso, ematoma intracerebra- le) ed extra-assiali (emorragia/ematoma epidurale, subdurale, in- traventricolare). Le lesioni traumatiche secondarie compaiono a distanza di tempo variabile dall\u2019evento traumatico e sono, in genere, la conseguen- za di un complesso meccanismo fisiopatologico scatenato dalle lesioni traumatiche primarie, potenzialmente prevenibili con un ef- ficace triage e un\u2019efficiente monitorizzazione del paziente critico. Il trauma cerebrale \ue8 un evento patologico dinamico e progres- sivo; e le varie lesioni secondarie rappresentano i diversi possibili aspetti di un medesimo processo fisiopatologico vascolare, fisico e biochimico, innescato dalla lesione primaria a seconda della gravit\ue0 di questa. Evidentemente, per massimizzare il recupero del paziente e per contenere quanto pi\uf9 possibile i danni successivi, \ue8 sul meccanismo patogenetico che occorre agire con finalit\ue0 pre- ventiva. Fondamentali sono un attento e costante monitoraggio neuroradiologico ed emodinamico. Quest\u2019ultimo comprende la valutazione di alcuni parametri quali l\u2019ossigenazione cerebrale (Sat.%.o2), la pressione di perfusione cerebrale (CPP), la pres- sione intracranica (ICP), la pressione sistemica. L\u2019assistenza al paziente con trauma cranio-encefalico richiede, pertanto, la tem- pestiva correzione dei parametri emodinamici tramite interventi farmacologici (idratazione iperosmolare, cauta iperventilazione, appropriata sedazione) ed eventualmente chirurgici (evacuazione di ematoma intracranico, craniotomia decompressiva, drenaggio liquorale). La gestione del trauma cerebrale \ue8 dunque focalizzata sulla prevenzione e sulla terapia del processo patologico alla base delle lesioni secondarie; il suo fine \ue8 sostanzialmente quello di mantenere una ottimale perfusione cerebrale

Valutazione dei talami in pazienti con epilessia del lobo temporale: uno studio H-MRS e VBM ad alto campo (3T)

Purpose: Dati elettrofisiologici hanno da piu` tempo eviden- ziato il coinvolgimento del circuito talamo-corticale nell\u2019e- pilessia del lobo temporale. Lo scopo di questo studio e` quindi quello di confermare, mediante spettroscopia di riso- nanza magnetica (H-MRS), l\u2019ipotesi che vi siano alterazioni metaboliche che sottendono possibili disfunzioni neuronali a carico dei talami in pazienti affetti da epilessia del lobo temporale e valutare eventuali correlazioni con i dati volumetrici. Methods: Sono stati presi in esame 20 pazienti epilettici affetti da epilessia temporale (17 F, 3 M) e 20 controlli sani. Gli esami sono stati condotti su un apparecchio 3 Tesla (Discovery MR750w, g.e.). L\u2019esame morfologico ha previsto oltre alle sequenze di base l\u2019 acquisizione di immagini volumetriche 3D T1-w FSPGR (TE 3,7; TR 9,8; Inversion time 750 ms; Flip angle 12; NEX, 1; 256 256 matrix; 1,0 mm sections, FOV 256 mm, bandwidth 25.00 HZ/pixel). I voxel spettroscopici (PRESS, TR 2000 ms, TE 35 ms, 192 acquisizioni) sono stati posizionati su entrambi i talami sia nei pazienti che nei controlli. I dati grezzi di ogni spettro sono stati analizzati mediante il programma LCModel. L\u2019analisivolumetrica(VBM)e`stataeffettuatamedianteun protocollo ottimizzato utilizzando il software SPM2. Result: I rapporti di Glx(Glu\ufe Gln)/Cr and Glu/Cr a livello dei talami sono risultati significativamente piu` alti nei pazienti rispetto aicontrolli sani (p < 0/.01). Correlazioni positive sono state rilevate tra Gln (glutammina) nel talamo sinsitro, il volume talamico omolaterale (r 1\u20444 0.648; p 1\u20444 0.043), ed il volume dell\u2019ippocampo sinistro (r 1\u20444 0,794; p 1\u20444 0,006). Mentreunacorrelazionenegativae`statarilevatatraGln del talamo sinistro e la durata di malattia (r 1\u20444 0,671; p 1\u20444 0.034). Conclusion: La H-MRS aggiunge ulteriori evidenze del coin- volgimento dei talami nel network epilettico mesiale lim- bico-temporale e conferma il ruolo del circuto Glu-Gln nella disfuzione neuronale correlata. Viene inoltre confermato in vivo come la riduzione di Gln possa avere un ruolo chiave nell\u2019eccitotossicita` corticale suggerendo possibili svi- luppi terapeutici