Objectives: This study aimed to investigate changes in three intrinsic functional connectivity networks (IFCNs; default mode network [DMN], salience network [SN], and task-positive network [TPN]) in individuals who had sustained a mild traumatic brain injury (mTBI).Methods: Resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired from 27 mTBI patients with persistent postconcussive symptoms, along with 26 age-and sex-matched controls. These individuals were recruited from a Level-1 trauma center, at least 3 months after a traumatic episode. IFCNs were established based on seed-to-voxel, region-of-interest (ROI) to ROI, and independent component analyses (ICA). Subsequently, we analyzed the relationship between functional connectivity and postconcussive symptoms.Results: Seed-to-voxel analysis of rs-fMRI demonstrated decreased functional connectivity in the right lateral parietal lobe, part of the DMN, and increased functional connectivity in the supramarginal gyrus, part of the SN. Our TPN showed both hypoand hyperconnectivity dependent on seed location. Within network hypoconnectivity was observed in the visual network also using group comparison. Using an ICA, we identified altered network functional connectivity in regions within four IFCNs (sensorimotor, visual, DMN, and dorsal attentional). A significant negative correlation between dorsal attentional network connectivity and behavioral symptoms score was also found. Conclusions:Our findings indicate that rs-fMRI may be of use clinically in order to assess disrupted functional connectivity among IFCNs in mTBI patients. Improved mTBI diagnostic and prognostic information could be especially relevant for athletes looking to safely return to play, as well for individuals from the general population with persistent postconcussive symptoms months after injury, who hope to resume activity.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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Sensorineural hearing loss (SNHL) is a common presenting complaint, particularly in the aging population [1] and can be caused by a wide range of pathologies affecting the cochlea, cranial nerve VIII, and the central auditory pathway. The central auditory pathway includes the bony and membranous labyrinth, the internal auditory canal (IAC), the cerebellopontine angle (CPA), the brain stem, the thalamus, and the temporal lobe. New diagnosis of SNHL is a common reason for requesting cross sectional imaging. Given the wide range of potential pathologies (Table 1), both high resolution computed tomography (CT) and gadolinium enhanced magnetic resonance imaging (MRI) are used in the initial assessment of SNHL although, where available, MRI is commonly used as first-line imaging. Causes of hearing loss that primarily present with conductive or mixed hearing loss such as otosclerosis, cholesteatoma, and temporal bone fracture are not included in the scope of this review. The most common cause of SNHL is presbycusis, affecting more than one-third of adults older than 75 years of age. Presbycusis is caused by age related degenerative changes involving the organ of Corti, which are beyond the resolution of current imaging techniques. Imaging is carried out to assess for alternative, potentially treatable, causes of SNHL. The purpose of this pictorial essay is to review important radiologic features of common and infrequent clinical entities related to SNHL through a casebased review.

The lacrimal gland is a bilobed serous gland located in the superolateral aspect of the orbit. Lacrimal system pathologies can be broadly divided into pathologies of the lacrimal gland and those of the lacrimal drainage system. These include distinct congenital, infectious, inflammatory, and benign, indeterminate, and malignant neoplastic lesions. Trauma and resultant fractures affecting lacrimal drainage apparatus is not part of this review; only non-traumatic diseases will be discussed. CT is the initial modality of choice because of its ability to delineate lacrimal system anatomy and demonstrate most lacrimal drainage system abnormalities and their extent. It also assesses bony architecture and characterizes the osseous changes. MRI is helpful in further characterizing these lesions and better assessing involvement of the surrounding soft tissue structures. In this pictorial review, we hope to revisit the anatomy of the lacrimal system, describe CT/MRI findings of the common/uncommon lacrimal system abnormalities and discuss relevance of imaging with regards to patient management.

Magnetic resonance imaging is an essential tool in the investigation of a patient with suspected temporal lobe pathology. Various conditions may affect this anatomic region, and, therefore, classification of imaging findings into specific groups may help provide a more focused differential diagnosis.