Survival Outcome Prediction in Glioblastoma: Insights from MRI Radiomics.

Background: Extracting multiregional radiomic features from multiparametric MRI for predicting pretreatment survival in isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM) patients is a promising approach. Methods: MRI data from 49 IDH wild-type glioblastoma patients pre-treatment were utilized. Diffusion and perfusion maps were generated, and tumor subregions segmented. Radiomic features were extracted for each tissue type and map. Feature selection on 1862 radiomic features identified 25 significant features. The Cox proportional-hazards model with LASSO regularization was used to perform survival analysis. Internal and external validation used a 38-patient training cohort and an 11-patient validation cohort. Statistical significance was set at p < 0.05. Results: Age and six radiomic features (shape and first and second order) from T1W, diffusion, and perfusion maps contributed to the final model. Findings suggest that a small necrotic subregion, inhomogeneous vascularization in the solid non-enhancing subregion, and edema-related tissue damage in the enhancing and edema subregions are linked to poor survival. The model's C-Index was 0.66 (95% C.I. 0.54-0.80). External validation demonstrated good accuracy (AUC > 0.65) at all time points. Conclusions: Radiomics analysis, utilizing segmented perfusion and diffusion maps, provide predictive indicators of survival in IDH wild-type glioblastoma patients, revealing associations with microstructural and vascular heterogeneity in the tumor.

"Long-term MRI findings in Ankylosing spondylitis patients treated with TNF inhibitors for a decade".

OBJECTIVE: This study aims to evaluate the active and chronic lesions in sacroiliac joints and lumbar spine over a decade of TNFi therapy in patients with AS. METHODS: The study enrolled patients with AS under treatment with a TNFi for over a decade. The patients underwent a new MRI scan of their lumbar spine and sacroiliac joint (SIJ). Two readers evaluated all images. Inflammation of SIJ (SIS), SIJ structural damage (SSS) including Fat Metaplasia, Erosions, Backfill and Ankylosis, and Spondyloarthritis Research Consortium of Canada Bone marrow edema (SPARCC) spine score were recorded. RESULTS: In the study, 15 patients were included, with 80% being male. The mean age during their first MRI was 38.1 (± 11.9) years old, and the majority (86.7%) tested positive for HLA-B27. While TNFi improved both BASDAI and BASFI scores, there was a noticeable increase in MRI acute lesions in the SIJ over time, where the median score increased from 0 (0-4) to 3 (0-10) after ten years (p = 0.028). After a decade of treatment, the median SPARCC spine score also increased from 0 (0-9) to 5 (0-16), p = 0.093. Finally, it was observed that there was a significant positive correlation between ESR and SIS erosions in cases of chronic lesions (r = 0.819, p < 0.001). CONCLUSIONS: While TNFi have significantly improved the treatment of AS, this study shows that acute lesions can still develop despite treatment. A personalized approach that adapts MRI assessment to each patient's specific requirements may help detect changes early and enable doctors to intervene promptly to prevent further damage.

The Role of Novel Imaging and Biofluid Biomarkers in Traumatic Axonal Injury: An Updated Review.

Traumatic brain injury (TBI) is a leading cause of disability worldwide. Traumatic axonal injury (TAI) is a subtype of TBI resulting from high-impact forces that cause shearing and/or stretching of the axonal fibers in white matter tracts. It is present in almost half of cases of severe TBI and frequently associated with poor functional outcomes. Axonal injury results from axonotomy due to mechanical forces and the activation of a biochemical cascade that induces the activation of proteases. It occurs at a cellular level; hence, conventional imaging modalities often fail to display TAI lesions. However, the advent of novel imaging modalities, such as functional magnetic resonance imaging and fiber tractography, has significantly improved the detection and characteristics of TAI. Furthermore, the significance of several fluid and structural biomarkers has also been researched, while the contribution of omics in the detection of novel biomarkers is currently under investigation. In the present review, we discuss the role of imaging modalities and potential biomarkers in diagnosing, classifying, and predicting the outcome in patients with TAI.

Brain Perfusion Changes in a Patient with Facial Trauma.

A 69-year-old male was admitted to our hospital because of left facial trauma with bone fractures, including the maxillary sinus, zygomatic arch, and ethmoid and sphenoid bones. Brain computed tomography was unremarkable but regional cerebral blood flow with hexamethyl-propylene-amine oxime single-photon emission computed tomography (SPECT) showed hypoperfusion of the left hemisphere, which was reversible since a repeat SPECT 4 months later was substantially improved. Brain perfusion SPECT may provide information on cerebrovascular status in some cases of facial injury.

Therapeutic Potential of Linearol in Combination with Radiotherapy for the Treatment of Glioblastoma In Vitro.

Glioblastoma is one of the most malignant and lethal forms of primary brain tumors in adults. Linearol, a kaurane diterpene isolated from different medicinal plants, including those of the genus Sideritis, has been found to possess significant anti-oxidant, anti-inflammatory and anti-microbial properties. In this study, we aimed to determine whether linearol could exhibit anti-glioma effects when given alone or in combination with radiotherapy in two human glioma cell lines, U87 and T98. Cell viability was examined with the Trypan Blue Exclusion assay, cell cycle distribution was tested with flow cytometry, and the synergistic effects of the combination treatment were analyzed with CompuSyn software. Linearol significantly suppressed cell proliferation and blocked cell cycle at the S phase. Furthermore, pretreatment of T98 cells with increasing linearol concentrations before exposure to 2 Gy irradiation decreased cell viability to a higher extent than linearol or radiation treatment alone, whereas in the U87 cells, an antagonistic relationship was observed between radiation and linearol. Moreover, linearol inhibited cell migration in both tested cell lines. Our results demonstrate for the first time that linearol is a promising anti-glioma agent and further studies are needed to fully understand the underlying mechanism of this effect.

Differentiation Between True Tumor Progression of Glioblastoma and Pseudoprogression Using Diffusion-Weighted Imaging and Perfusion-Weighted Imaging: Systematic Review and Meta-analysis.

BACKGROUND: On brain magnetic resonance imaging, both diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) are used to evaluate cerebral tumors. The purpose of this meta-analysis was to evaluate and compare the diagnostic performance of DWI and PWI in differentiating between pseudoprogression and true tumor progression of glioblastoma. METHODS: We performed a systematic review of the PubMed database from January 2000 to December 2019 for relevant studies. After application of specific inclusion and exclusion criteria, the eligible articles were evaluated for methodologic quality and risk of bias using the updated Quality Assessment of Diagnostic Accuracy (QUADAS-2) tool. From the published study results, the pooled sensitivity, pooled specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio and their corresponding confidence intervals (% CI), and the area under the curve, were calculated individually for DWI and PWI. RESULTS: The meta-analysis included 24 studies, with a total of 900 patients. DWI was found to be slightly superior in terms of sensitivity and specificity, 0.88 (% CI 0.83-0.92) and 0.85 (% CI 0.78-0.91), respectively, compared with the respective values of PWI, 0.85 (% CI 0.81-0.89) and 0.79 (% CI 0.74-0.84). On comparison of the overall diagnostic accuracy of the MRI modalities using their respective area under the curve values (0.9156 for DWI, 0.9072 for PWI), no significant difference was demonstrated between the 2. CONCLUSIONS: Both DWI and PWI provided optimal diagnostic performance in differentiating pseudoprogression from true tumor progression in cerebral glioblastoma, and neither technique proved to be superior.

Functional connectivity and microstructural changes of the brain in primary Sjögren syndrome: the relationship with depression.

BACKGROUND: Fatigue and depression are among the most common manifestations of primary Sjögren syndrome (pSS), but information is lacking on the relationship with brain function and microstructural changes. PURPOSE: To investigate microstructural changes and brain connectivity in pSS, and to evaluate their relationship with fatigue and depression. MATERIAL AND METHODS: The study included 29 patients with pSS (mean age 61.2 ± 12.1 years; disease duration 10.5 ± 5.9 years) and 28 controls (mean age 58.4 ± 9.2 years). All the patients completed the Beck's depression and Fatigue Assessment Scale questionnaires. The imaging protocol consisted of: (i) standard magnetic resonance imaging (MRI) pulse sequences (FLAIR, 3D T1W); (ii) a diffusion tensor imaging pulse sequence; and (iii) a resting state functional MRI pulse sequence. Resting state brain networks and maps of diffusion metrics were calculated and compared between patients and controls. RESULTS: Compared with the controls, the patients with pSS and depression showed increased axial, radial, and mean diffusivity and decreased fractional anisotropy; those without depression showed decreased axial diffusivity in major white matter tracts (superior longitudinal fasciculus, inferior longitudinal fasciculus, corticospinal tract, anterior thalamic radiation, inferior fronto-occipital fasciculus, cingulum, uncinate fasciculus, and forceps minor-major). Decreased brain activation in the sensorimotor network was observed in the patients with pSS compared with the controls. No correlation was found between fatigue and structural or functional changes of the brain. CONCLUSION: pSS is associated with functional connectivity abnormalities of the somatosensory cortex and microstructural abnormalities in major white matter tracts, which are more pronounced in depression.

Postpartum intracranial hypotension complicated by posterior reversible encephalopathy syndrome: a case report.

Purpose: To present an unusual case of posterior encephalopathy syndrome (PRES) preceded by intracranial hypotension.Materials and Methods: We present a case of a 27-year-old parturient with an uneventful pregnancy that shortly after labor developed a persistent headache with characteristics compatible with intracranial hypotension. The patient had undergone epidural anesthesia for caesarian section. Results: The symptomatology of intracranial hypotension was attributed to inadvertent dural puncture during epidural anesthesia. The MRI revealed multiple white matter lesions located in frontal, temporal and parietal regions of both hemispheres. The type of lesions was suggestive of PRES. Pachymeningeal enhancement was also observed. The patient was managed conservatively. The symptoms improved gradually and the imaging findings resolved completely. Conclusions: This case demonstrates the need for clinical alertness for PRES in patients with prolonged and possibly atypical symptoms of intracranial hypotension. As probable causal relationship between these disorders we propose a sympathetic over-activation as a result of cerebrospinal fluid leakage leading to vasospasm and manifestation of PRES.

Functional and structural connectivity of the brain in very preterm babies: relationship with gestational age and body and brain growth.

BACKGROUND: Structural and functional changes of the brain have been reported in premature babies. OBJECTIVE: To evaluate the relationship of functional and structural connectivity with gestational age, body growth and brain maturation in very preterm babies. MATERIALS AND METHODS: We studied 18 very preterm babies (gestational age: mean ± standard deviation, 29.7±1.7 weeks). We examined functional connectivity by multivariate pattern analysis of resting-state functional MRI data. We assessed structural connectivity by analysis of diffusion tensor imaging data and probabilistic tractography. RESULTS: The average functional connectivity of the medial orbitofrontal cortex with the rest of the brain was positively associated with gestational age (P<0.001). Fractional anisotropy of the right inferior fronto-occipital fasciculus was positively associated with head circumference at term-equivalent age. Structural connectivity of the inferior fronto-occipital fasciculus with the medial orbitofrontal cortex was positively associated with head circumference at term-equivalent age. Body weight at term-equivalent age was the only independent predictor of average structural connectivity of the medial orbitofrontal cortex with the rest of the brain (P=0.020). CONCLUSION: Structural and functional connectivity of the medial orbitofrontal cortex with the rest of the brain depend on body growth and degree of prematurity, respectively.

Primary vitreoretinal lymphoma.

Primary vitreoretinal lymphoma (PVRL) is a rare ocular lymphoid malignancy, which consists a subset of primary central system lymphoma (PCNSL) and the most common type of intraocular lymphoma. The involvement of eyes is estimated to be approximately 20% of PCNSL, but the brain involvement may be up to 80% of PVRL. Typically, PVRL is a high grade B-cell malignancy of the retina and needs to be assorted from choroidal low-grade B-cell lymphomas. Very often PVRL masquerades and can be erroneously diagnosed as chronic uveitis, white dot syndromes or other neoplasms. Establishing an accurate diagnosis may involve cytology/pathology, immunohistochemistry, flow cytometry, molecular pathology and cytokine profile analysis. There is inadequate information about PVRL's true incidence, ethnic/geographical variation and pathogenetic mechanisms. The therapeutic approach of PVRL involves aggressive chemotherapy and radiation therapy. Although PVRL tends to have a good response to the initial treatment, the prognosis is poor and the survival restricted due to the high relapse rates and CNS involvement.

Multifocal alterations of white matter accompany the transition from normal cognition to dementia in Parkinson's disease patients.

The purpose of the present study was to investigate the pattern of white matter (WM) changes associated with Parkinson's disease (PD)-related cognitive impairment by using fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) measures. Diffusion Tensor Imaging (DTI) was performed in 21 PD-patients with dementia (PDD) and in an age-matched control group including 40 PD-patients without dementia (PD-CTRL). The Parkinson's disease-Cognitive Rating Scale (PD-CRS) was used for patients' neuropsychological assessment. Local microstructural WM differences associated with the presence of cognitive impairment were tested using tract-based spatial statistics analysis. Multiple regression models investigated the association of DTI indices with total PD-CRS score, PD-CRS raw items and other clinical measures across the whole study sample. Significant FA decreases were found in PDD compared to PD-CTRL patients mainly in the body of corpus callosum, corona radiata and cingulum. Lower PD-CRS score was significantly associated with decreased FA, MD and AD values in multiple WM tracts primarily located in prefrontal and limbic areas as well as across the corpus callosum. Lower performance in specific PD-CRS raw items was also associated with FA decreases in major WM tracts. The results suggest that multifocal microstructural changes of WM accompany the transition from normal to demented cognitive state in PD-patients. The corpus callosum, the corona radiata and the cingulum are among the regions mostly affected during this course. A progressive axonal degeneration is proposed as a key underlying mechanism.

Adult intradural extramedullary teratoma of the spinal cord: A case presentation.

Teratomas involving the spinal cord are very rare tumors that affect more commonly children than adult. We report a rare case of an intradural extramedullary teratoma arising in the region of conus medullaris in a previously healthy adult patient. The lesion was totally excised and the postsurgical outcome was favorable. Teratomas should be taken into consideration in the differential diagnosis in previously healthy adults with sudden onset of lower back pain or neurological deficits of the lower extremities and with a tumoral lesion of the spinal cord. Total surgical excision is the indicative treatment of choice.

Pseudoexfoliation syndrome without glaucoma: White matter abnormalities detected by conventional MRI and diffusion tensor imaging.

PURPOSE: To assess macro- and microstructural brain changes in patients with pseudoexfoliation syndrome (PXS). MATERIALS AND METHODS: Comprehensive ophthalmic examination and brain MRI were conducted on 20 patients with PXS without glaucoma (aged 62.75 ±â€¯0.4 years) and 20 controls (aged 62 ±â€¯0.6 years). White matter (WM) integrity was evaluated on FLAIR and single-shot multisection SE-EPI diffusion tensor imaging (DTI) sequences. The presence and the number of white matter hyperintensities (WMHIs) on FLAIR images was compared between all patients and control subjects. Microstructural WM changes on DTI was evaluated using Tract-based spatial statistics (TBSS). DTI metrics of the optic tracts were assessed by the region-of-interest (ROI) method. RESULTS: A significantly higher number of WMHIs was found in the patients with PXS than in the control subjects (P ≤ 0.002). On DTI the patients showed bilateral increase in the mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) values in the anterior thalamic radiation, the inferior fronto-occipital fasciculus, the superior longitudinal fasciculus, the inferior longitudinal fasciculus and the forceps minor. TBSS revealed no significant difference in fractional anisotropy (FA) values, but ROIs analysis of the optic tracts revealed decreased FA values in the patients. CONCLUSION: MRI in patients with PXS detects abnormalities in the brain and the optic tracts at a subclinical stage. Early detection of microstructural changes could be useful to guide appropriate treatment to impede the disease process.

Radiation Necrosis, Pseudoprogression, Pseudoresponse, and Tumor Recurrence: Imaging Challenges for the Evaluation of Treated Gliomas.

Glioblastoma (GBM) is the most common primary malignant type of brain neoplasm in adults and carries a dismal prognosis. The current standard of care for GBM is surgical excision followed by radiation therapy (RT) with concurrent and adjuvant temozolomide-based chemotherapy (TMZ) by six additional cycles. In addition, antiangiogenic therapy with an antivascular endothelial growth factor (VEGF) agent has been used for recurrent glioblastoma. Over the last years, new posttreatment entities such as pseudoprogression and pseudoresponse have been recognized, apart from radiation necrosis. This review article focuses on the role of different imaging techniques such as conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), dynamic contrast enhancement (DCE-MRI) and dynamic susceptibility contrast (DSE-MRI) perfusion, magnetic resonance spectroscopy (MRS), and PET/SPECT in differentiation of such treatment-related changes from tumor recurrence.

Mitochondrial Membrane Dynamics and Inherited Optic Neuropathies.

Inherited optic neuropathies are a genetically diverse group of disorders mainly characterized by visual loss and optic atrophy. Since the first recognition of Leber's hereditary optic neuropathy, several genetic defects altering primary mitochondrial respiration have been proposed to contribute to the development of syndromic and non-syndromic optic neuropathies. Moreover, the genomics and imaging revolution in the past decade has increased diagnostic efficiency and accuracy, allowing recognition of a link between mitochondrial dynamics machinery and a broad range of inherited neurodegenerative diseases involving the optic nerve. Mutations of novel genes modifying mainly the balance between mitochondrial fusion and fission have been shown to lead to overlapping clinical phenotypes ranging from isolated optic atrophy to severe, sometimes lethal multisystem disorders, and are reviewed herein. Given the particular vulnerability of retinal ganglion cells to mitochondrial dysfunction, the accessibility of the eye as a part of the central nervous system and improvements in technical imaging concerning assessment of the retinal nerve fiber layer, optic nerve evaluation becomes critical - even in asymptomatic patients - for correct diagnosis, understanding and early treatment of these complex and enigmatic clinical entities.

The association between multiple sclerosis and spondylosis: When and why.

OBJECTIVES: To evaluate risk factors for the development of cervical spine spondylosis (CSS) in patients with multiple sclerosis (MS) and to propose a pathogenetic mechanism. METHODS: Forty-two consecutive patients aged 23-66 years with MS and 42 age and sex matched controls were evaluated retrospectively; Clinical disability was evaluated with the expanded disability status scale (EDSS) and spasticity with the Asworth score. Total brain lesion volume (BLV), total grey matter (GM) volume and deep GM volume were assessed. In the cervical spine CSS indices (disk dehydration, disk protrusion, abnormal posture and osteophytosis) and the spinal cord lesion load (SLL) was evaluated. The association of CSS indices with the presence of MS, the clinical scales and the brain and spinal cord imaging measurements were assessed. RESULTS: Presence of MS was positively associated with abnormal posture (P=0.002), disk dehydration at C6-C7 (P=0.049) and posterior disk protrusion at C5-C6 (P=0.033) and C6-C7 (P=0.001). All patients had spasticity. Patients with abnormal posture were younger (37.5±11.1years) than those with normal (45.4±8.6years), P=0.024. Age (P=0.008), EDSS (P=0.045) and BLV (P=0.084) were significant independent predictors of abnormal posture. Younger age combined with worse EDSS and increased BLV predicted abnormal posture. CONCLUSIONS: Patients with MS present more frequently spondylosis which is associated with younger age, more severe disability and extensive lesions in the brain. Spasticity induced by the brain lesions and abnormal expression of extracellular matrix proteins in the brain and the intervertebral disk constitute a possible pathogenetic mechanism.

Regional Cerebral Blood Flow SPECT and MRI in Logopenic Variant Primary Progressive Aphasia.

We report a 61-year-old woman who presented because of gradually progressive speech disorders. MRI scan revealed left temporal lobe atrophy with ex vacuo dilatation of the temporal horn and atrophy of the left inferior frontal gyrus and the left inferior parietal lobe. These findings in brain perfusion SPECT corresponded to a generalized hypoperfusion of the left hemisphere, particularly prominent on the rear parietal cortex and the temporal lobe. After taking into consideration the clinical presentation and imaging findings on MRI and SPECT, the diagnosis of the logopenic variant of primary progressive aphasia was finally reached.

Abnormalities of brain neural circuits related to obesity: A Diffusion Tensor Imaging study.

PURPOSE: Increased Body-Mass-Index (BMI) has been associated with brain atrophy in both gray and white matter structures. However, little is known concerning the integrity of white matter tracts in obesity. The purpose of the study was to evaluate the pattern of changes in white matter microstructure in human adiposity. MATERIAL AND METHODS: The study included 268 participants (52 obese, 96 overweight and 120 normal-weight) that were retrospectively evaluated by Diffusion Tensor Imaging. The fractional anisotropy, axial, radial and mean diffusivity values were compared between the above groups using Tract Based Spatial Statistics. RESULTS: The analysis revealed that the increased BMI was related with decreased fractional anisotropy in several white matter regions including the anterior and posterior thalamic radiation, the inferior fronto-occipital fasciculus, the inferior and superior longitudinal fasciculus, the corpus callosum (callosal body and forceps minor), the uncinate fasciculus, the internal capsule, the corticospinal tract and the cingulum (cingulate gyrus and hippocampus). CONCLUSIONS: Anisotropic diffusion of anatomic regions governing important brain circuits such as reward seeking inhibition, motivation/drive and learning/conditioning decreases with increasing BMI.