Quantitative computed tomography (CT) assessment of emphysema in patients with severe chronic obstructive pulmonary disease (COPD) and its correlation with age, sex, pulmonary function tests, BMI, smoking, and biomass exposure

Background: To evaluate the role of HRCT in quantifying emphysema in severe COPD patients and to study the variations in the pattern of emphysema in relation to age, sex, FEV1, smoking index, biomass exposure, and BMI. Material/Methods: Automatic lung segmentation of HRCT scans in 41 severe COPD patients (GOLD stage III or more) was done using an emphysema protocol. The extent of emphysema was assessed using the density mask method with a threshold of -950 HU (%LAA-950). The percentage of emphysema in each lung lobe and both lungs was correlated with 6 parameters - age, sex, BMI, smoking index, biomass exposure, and FEV1. Results: Smoking resulted in homogenously distributed emphysema regardless of the severity of smoking. BMI was inversely correlated with the extent of emphysema. A significant association was found between the percentage of emphysema in the right lower lobe and BMI (P=0.015), between biomass exposure and the percentage of emphysema in RUL, RLL, and both lungs (P values of 0.024, 0.016, and 0.036, respectively). The extent of emphysema was disproportionately low compared to the amount of obstruction on PFTs, indicating an airway predominant variety of COPD with significant biomass exposure. Conclusions: Smoking is associated with a relatively homogenous distribution of emphysema with no regional predilection. Biomass exposure produces predominantly right-sided emphysema. BMI decreases with increasing levels of emphysema in the right lower lobe. These risk factors of emphysema patterns are helpful in deciding on the management, including surgical options

Temporal encephalocele into transverse sinus in an adult with partial seizures: MRI evaluation of a rare site of brain herniation

Herniation of brain parenchyma outside its normal enclosure (also known as encephalocele) has long been known to occur at certain classic sites and is classified accordingly. With widespread use of modern neuroimaging, the previously unknown atypical and rare sites of encephalocele have now been identified. Brain herniation into a dural venous sinus is one such recently described entity with case reports extending only upto the earlier part of this decade. With no definite clinical symptomatology, imaging is crucial to diagnose this lesion accurately and differentiate it from the more familiar entity in this region of the brain, the arachnoid granulations. Also known as occult encephalocele, focal brain herniation into dural venous sinus has few specific imaging features and characteristic sites. We report a case of a 21-year-old man with partial seizures in whom MRI of the brain revealed focal herniation of the normal temporal lobe parenchyma into the left transverse sinus and discuss the key imaging features and pathophysiology of this entity

MRI evaluation of Kimura’s disease with emphasis on diffusion weighted imaging and enhancement characteristics

Kimura’s disease is a rare disease of the head and neck region affecting mainly the adult males in eastern countries. The parotid and periparotid subcutaneous regions are the most common sites in head and neck region. Coupled with peripheral eosinophilia and raised serum IgE levels as characteristic features on hemogram, a painless swelling in parotid and periparotid region is diagnostic of Kimura’s disease. Magnetic resonance imaging (MRI) has been an important modality in evaluating lesions of the head and neck region. Recently, interest in the diffusion weighted imaging (DWI) and contrast enhanced MRI (CEMRI) imaging of lesions in Kimura’s disease has been noted to characterize it and differentiate it from other pathologies. We describe a case a recurrent Kimura’s disease of the periparotid region and its MRI features with special emphasis on its characteristics on DWI and contrast enhanced sequences

Dural Ectasia of the Optic Nerve: A Rare Presentation in Neurofibromatosis Type I

Neurofibromatosis Type 1 (NF-1) is a common neurocutaneous syndrome with a characteristic spectrum of pathologies affecting the optic pathway. Optic pathway glioma and optic nerve meningioma are two such common afflictions of the optic nerve in NF-1. Dural ectasia of the optic nerve also known as optic nerve meningocele is a rare manifestation of optic nerve involvement in NF-1. Magnetic resonance imaging (MRI) is an excellent modality to accurately identify, characterize, delineate, and differentiate dural ectasia of the optic nerve from the commoner lesions such as optic glioma and meningioma in NF-1. We describe a case of a young woman with NF and a large recurrent palpebral neurofibroma. MRI evaluation of the orbits revealed extensive ectasia of the dura lining the cerebrospinal fluid sheath around all the segments of the optic nerve and around the optic chiasm

An Educational Training Kit for an Efficient GPS Anti-Jamming System

Global positioning system (GPS) is one of the key satellite-based radio technolo-gy providing navigational services on earth or near earth. The increasing usage of GPS applications in daily life has proved that students/researchers of many edu-cational departments including information and communication technology (ICT) are particularly interested to learn and visualize the GPS anti-jamming techniques in a simpler way in their major communication courses. It is a fact that GPS radio signal is vulnerable in various ways to jamming signals launched by malicious el-ements. The traditional available GPS anti-jamming techniques generally involve either added hardware and/or computational complexity which introduce difficul-ty for students to understand the basic concepts. As an alternative, this paper pre-sents a simpler GPS anti-jamming system kit based on L1-band (1.575 GHz) of GPS for education purpose. More specifically, the proposed antenna array, inte-grated with two couplers, cancels out the jamming signal in radio frequency (RF) domain using sum and difference patterns generated by the latter. The simulated and measured results, in terms of scattering parameters and power profiles, of the proposed system have shown that the jamming signal can be eliminated with less complexity. Eventually, the proposed GPS anti-jamming system has great poten-tial to be used in ICT related disciplines for learning and training purposes