High-resolution DCE-MRI of the pituitary gland using radial k-space acquisition with compressed sensing reconstruction

BACKGROUND AND PURPOSE: The pituitary gland is located outside of the blood-brain barrier. Dynamic T1 weighted contrast enhanced sequence is considered to be the gold standard to evaluate this region. However, it does not allow assessment of intrinsic permeability properties of the gland. Our aim was to demonstrate the utility of radial volumetric interpolated brain examination with the golden-angle radial sparse parallel technique to evaluate permeability characteristics of the individual components (anterior and posterior gland and the median eminence) of the pituitary gland and areas of differential enhancement and to optimize the study acquisition time. MATERIALS AND METHODS: A retrospective study was performed in 52 patients (group 1, 25 patients with normal pituitary glands; and group 2, 27 patients with a known diagnosis of microadenoma). Radial volumetric interpolated brain examination sequences with goldenangle radial sparse parallel technique were evaluated with an ROI-based method to obtain signal-time curves and permeability measures of individual normal structures within the pituitary gland and areas of differential enhancement. Statistical analyses were performed to assess differences in the permeability parameters of these individual regions and optimize the study acquisition time. RESULTS: Signal-time curves from the posterior pituitary gland and median eminence demonstrated a faster wash-in and time of maximum enhancement with a lower peak of enhancement compared with the anterior pituitary gland (P .005). Time-optimization analysis demonstrated that 120 seconds is ideal for dynamic pituitary gland evaluation. In the absence of a clinical history, differences in the signal-time curves allow easy distinction between a simple cyst and a microadenoma. CONCLUSIONS: This retrospective study confirms the ability of the golden-angle radial sparse parallel technique to evaluate the permeability characteristics of the pituitary gland and establishes 120 seconds as the ideal acquisition time for dynamic pituitary gland imaging

The ketogenic diet increases in vivo glutathione levels in patients with epilepsy

The Ketogenic Diet (KD) is a high-fat, low-carbohydrate diet that has been utilized as the first line treatment for contrasting intractable epilepsy. It is responsible for the presence of ketone bodies in blood, whose neuroprotective effect has been widely shown in recent years but remains unclear. Since glutathione (GSH) is implicated in oxidation-reduction reactions, our aim was to monitor the effects of KD on GSH brain levels by means of magnetic resonance spectroscopy (MRS). MRS was acquired from 16 KD patients and seven age-matched Healthy Controls (HC). We estimated metabolite concentrations with linear combination model (LCModel), assessing differences between KD and HC with t-test. Pearson was used to investigate GHS correlations with blood serum 3-B-Hydroxybutyrate (3HB) concentrations and with number of weekly epileptic seizures. The results have shown higher levels of brain GSH for KD patients (2.5 ± 0.5 mM) compared to HC (2.0 ± 0.5 mM). Both blood serum 3HB and number of seizures did not correlate with GSH concentration. The present study showed a significant increase in GSH in the brain of epileptic children treated with KD, reproducing for the first time in humans what was previously observed in animal studies. Our results may suggest a pivotal role of GSH in the antioxidant neuroprotective effect of KD in the human brain

The role of time-resolved imaging of contrast kinetics (TRICKS) magnetic resonance angiography (MRA) in the evaluation of head-neck vascular anomalies: A preliminary experience

Objectives: In this preliminary report, we describe our experience with time-resolved imaging of contrast kinetics-MR angiography (TRICKS-MRA) in the assessment of head-neck vascular anomalies (HNVAs). Methods: We prospectively studied six consecutive patients with clinically suspected or diagnosed HNVAs. All of them underwent TRICKS-MRA of the head and neck as part of the routine for treatment planning. A digital subtraction angiography (DSA) was also performed. Results: TRICKS-MRA could be achieved in all cases. Three subjects were treated based on TRICKS-MRA imaging findings and subsequent DSA examination. In all of them, DSA confirmed the vascular architecture of HNVAs shown by TRICKS-MRA. In the other three patients, a close follow up to assess the evolution of the suspected haemangioma was preferred. Conclusions: TRICKS sequences add important diagnostic information in cases of HNVAs, helpful for therapeutic decisions and post-treatment follow up. We recommend TRICKSMRA use (if technically possible) as part of routine MRI protocol for HNVAs, representing a possible alternative imaging tool to conventional DSA

Differential diagnosis of neurodegenerative dementias with the explainable MRI based machine learning algorithm MUQUBIA

Biomarker-based differential diagnosis of the most common forms of dementia is becoming increasingly important. Machine learning (ML) may be able to address this challenge. The aim of this study was to develop and interpret a ML algorithm capable of differentiating Alzheimer’s dementia, frontotemporal dementia, dementia with Lewy bodies and cognitively normal control subjects based on sociodemographic, clinical, and magnetic resonance imaging (MRI) variables. 506 subjects from 5 databases were included. MRI images were processed with FreeSurfer, LPA, and TRACULA to obtain brain volumes and thicknesses, white matter lesions and diffusion metrics. MRI metrics were used in conjunction with clinical and demographic data to perform differential diagnosis based on a Support Vector Machine model called MUQUBIA (Multimodal Quantification of Brain whIte matter biomArkers). Age, gender, Clinical Dementia Rating (CDR) Dementia Staging Instrument, and 19 imaging features formed the best set of discriminative features. The predictive model performed with an overall Area Under the Curve of 98%, high overall precision (88%), recall (88%), and F1 scores (88%) in the test group, and good Label Ranking Average Precision score (0.95) in a subset of neuropathologically assessed patients. The results of MUQUBIA were explained by the SHapley Additive exPlanations (SHAP) method. The MUQUBIA algorithm successfully classified various dementias with good performance using cost-effective clinical and MRI information, and with independent validation, has the potential to assist physicians in their clinical diagnosis

Observations on the growth of temporalis muscle. A 3D CT imaging study

This study investigates the hypothesis that there is, during childhood, a disproportionate age-related expansion of the origin of temporalis muscle compared to the growth of the underlying skull. Lateral projections of 50 randomly selected 3D reformatted computerized tomographic (CT) scans (yielding 100 temporalis muscles) of children aged >0.6 to 15 years scanned for conditions that did not affect the shape of their head or face were windowed to provide the optimum delineation of temporalis muscle against the underlying bone. Vertical and anterior–posterior measurements of the muscle made independently by two observers were compared with those of the skull along the same planes. The development of the anterior temporal crest was also assessed. The intraclass correlation coefficient for differences in the measurements made by each observer ranged from good to excellent. The muscle and skull measurements were used to produce a ratio of muscle-to-skull lengths in both vertical and horizontal planes. Analysis of these ratios showed a statistically significant increase in the vertical reach of temporalis with age (Pearson correlation coefficient (R) =0.7826; p < 0.05) compared to the growth of the skull along the planes chosen for the study—but less so for its horizontal reach (R = 0.5073. p <.001). There were no significant differences between right/left or male/female measurements. There was also a substantial level of agreement between both observers in their assessment of the development of the temporal crest. The mean age of children in whom a fully formed temporal crest could be identified (10.6 years) was significantly greater (p < 0.001) than that of the 38 remaining subjects (6.0 years). These results confirm that there is, in response to increased masticatory/dietary demands during childhood, a disproportionate increase in the vertical and (to a lesser extent) horizontal reach of temporalis muscle over its origin from the temporal, frontal, sphenoid, and parietal bones compared the growth of the skull. It is proposed that surgical interference with this normal process is responsible for the soft tissue component of late-developing deformity that can occur following early (at 6–18 months of age) operations for the correction of trigonocephalic head shape associated with metopic synostosis

Reply to. “Is the spinal cord truly affected in half of the patients with Kearns-Sayre syndrome?” and “Spinal cord and heart involvement in Kearns Sayre Syndrome. which link?”

No abstract availabl

Multiparametric evaluation of low grade gliomas at followup: Comparison between diffusion and perfusion MR with 18F-FDOPA PET

Objective: To compare MRI using perfusion and diffusion techniques with 6-[18F]-fluoro-L-3,4-dihydroxyphenylalanine (18F-FDOPA) positron emission tomography (PET) in the follow-up of low-grade gliomas (LGGs) and to identify the best imaging parameter to differentiate patients with different prognosis. Methods: Between 2010 and 2015, 12 patients with a pathology-proven diagnosis of LGG and MR (with perfusion and diffusion sequences) and a PET study during their follow-up were retrospectively included in our study. Cerebral blood volume (CBV) and apparent diffusion coefficient (ADC) maps on MR studies and PET images were evaluated using a region of interest-based method. All patients were categorized as stable or as having progressive disease at 1-year follow-up. Statistical analysis was performed using Pearson's correlation test and multivariate analysis of variance (p,0.05). Results: No significant correlations were found between PET parameters [maximum tumour-to-controlateral normal brain ratio (T/Nmax) and tumour-to-striatum ratio] and ADC or relative CBV values measured in both PET hotspot regions and areas of maximum signal alterations. T/Nmax demonstrated a good sensitivity (83%) and specificity (100%) for differentiating two subgroups of patients with different outcomes at 1-year-follow-up (p,0.05). Conclusion: Perfusion and diffusion MR images provide different information compared with 18F-FDOPA PET in LGGs during follow-up and therefore, they should be considered as complementary tools in the evaluation of these tumours. 18F-FDOPA PET showed a significant prognostic role in the follow-up of LGGs and appeared to be a better tool than MR advanced techniques for outcome prediction. These results need to be confirmed with longitudinal studies on a larger population

Langerhans' cell histiocytosis mimicking a pott puffy tumor

Langherans' cell histiocytosis (LCH) is a rare disease mostly affecting children in the first decade of life. As clinical presentation is extremely heterogenous, a prompt diagnosis may be challenging, sometimes leading to a diagnostic delay, especially when the disease involves a single site. Herein, we report a case of a child with an unusual presentation of (LCH) mimicking a Pott puffy tumor with extracranial and epidural abscesses, surgically treated. Through this unique case we summarize possible manifestations of LCH with bone involvement and we underline the importance of considering possible complications due to bone erosions such as infection, to avoid a misdiagnosis

A new MRI severity score to predict long-term adverse neurologic outcomes in children with congenital Cytomegalovirus infection

Background: Congenital cytomegalovirus (CMV) infection is one of the main causes of deafness in childhood. It frequently causes serious long-term neurological sequelae. In children who are asymptomatic at birth, tests to accurately predict these sequelae are still unavailable. Aims: We describe different brain MRI patterns of congenital CMV infection correlated with clinical data and propose a new MRI severity score to early predict long-term neurological sequelae. Materials and methods: We explored clinical records and neuroimaging data of 224 neonates and children with congenital Cytomegalovirus infection, 180 of them did not meet inclusion criteria. Forty-four babies met inclusion criteria and were enrolled in the study. We retrospectively collected clinical data concerning hospitalization, 2 years outpatient follow-up and brain MRI findings of those 44 children, symptomatic and asymptomatic at birth. Clinical data were then correlated with children’s brain MRI examinations. We defined neurological and sensorial impairment (hearing or visual) as “adverse neurological outcomes”. Brain MRI score was constructed assigning different values to white matter and ventricular dilation. Results: In 44 children enrolled in the study we found that 28/35 (80%) with abnormal and 2/9 (22,2%) with normal MRI examination developed adverse neurological outcomes (OR = 3.6) (95% IC 1.0–12.0). Infants who were symptomatic at birth showed a probability of MRI brain lesions 3.2 times higher than those who were asymptomatic. Ten out of 17 (59%) children who were asymptomatic at birth showed MRI-WM alterations or ventriculomegaly. Conclusions: Brain MRI abnormalities, such as WM alterations and ventriculomegaly, expressed as MRI score higher than 2 are associated with an increased probability of long-term adverse neurological outcome in congenitally CMV infected infants, symptomatic and asymptomatic at birth