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Cerebral intracranial aneurysms are serious problems that can lead to stroke, coma, and even death. The effect of blood flow on cerebral aneurysms and their relationship with rupture are unknown. In addition, postural changes and their relevance to haemodynamics of blood flow are difficult to measure in vivo using clinical imaging alone. Computational simulations investigating the detailed haemodynamics in cerebral aneurysms have been developed in recent times not only to understand the progression and rupture but also for clinical evaluation and treatment. In the present study, the haemodynamics of a patient-specific case of a large aneurysm on the left side internal carotid bifurcation (LICA) and no aneurysm on the right side internal carotid bifurcation (RICA) was investigated. The simulation of these patient-specific models using fluid–structure interaction provides a valuable comparison of flow behavior between normal and aneurysm models. The influences of postural changes were investigated during standing, sleeping, and head-down (HD) position. Significant changes in flow were observed during the HD position and quit high arterial blood pressure in the internal carotid artery (ICA) aneurysm model was established when compared to the normal ICA model. The velocity increased abruptly during the HD position by more than four times (LICA and RICA) and wall shear stress by four times (LICA) to ten times (RICA). The complex spiral flow and higher pressures prevailing within the dome increase the risk of aneurysm rupture. [ABSTRACT FROM AUTHOR]

This is the second part of the two-part paper on the history of development of neuroradiology at the Sree Chitra Tirunal Institute of Medical Sciences and Technology, Thiruvananthapuram. In this part, the authors describe the evolution of interventional procedures at their institute from the initial techniques of free-flow embolization as a palliative procedure for large arteriovenous malformations (AVMs) to the more refined techniques of selective embolization using microcatheters, calibrated leak balloons and liquid polymerizing embolic agents. The authors acknowledge the immense encouragement and support provided to them by the French neurointervention pioneers Prof. Luc Picard and Prof. Jacques Moret in this endeavor. [ABSTRACT FROM AUTHOR]

This article is a historical narrative that traces the growth of neuroradiology and interventional radiology at the Sree Chitra Tirunal Institute of Medical Sciences and Technology, Thiruvananthapuram. From its humble origins in the pre-CT scan era of the mid and late 1970s, when invasive diagnostic procedures such as percutaneous carotid angiography, myelography, pneumoencephalography (PEG) and ventriculography were the mainstay of neuroimaging, the authors take the reader through their gradual foray into catheter four-vessel angiography and later free-flow embolization of arteriovenous malformations (AVMs), and finally to the use of microcatheters for selective embolization procedures. The equipment used in those early years—fluoroscopic tilting table, roll-film cameras, serial changers, PEG tables—provide an insight to an era with all its challenges before the advent of digital imaging. The authors’ efforts to indigenize some of the hardware such as metallic stents and embolization material such as hydrogel spheres and lyophilized dura are also highlighted. The development of peripheral vascular intervention alongside neuroradiology is also highlighted. The authors pay tribute to an early pioneer of neuroradiology in India, Prof. Mahadevan Pillai, who was a guiding light to them during those nascent years. [ABSTRACT FROM AUTHOR]

Study Design: Observational comparative study. Purpose: To compare fractional anisotropy (FA) maps with T2 values of the nucleus pulposus (NP) and annulus fibrosus (AF) of intervertebral discs in healthy volunteers and patients to develop a predictive disc health scale. Overview of Literature: T2-weighted magnetic resonance imaging (MRI) is not sensitive to early morphological changes and provides no quantitative biomarker profile for early degeneration. Methods: We examined 59 healthy controls and 59 patients with back pain by MRI using T2 relaxometry and diffusion tensor imaging (DTI). Each group was divided into three age subgroups: A (<30 years, n=12); B (30-50 years, n=26); and C (>50 years, n=21). We obtained FA values for AF and NP and T2 values for NP for each intervertebral disc. Furthermore, we calculated the FA (AF/NP) ratios. Results: We categorized 590 intervertebral discs from 118 participants, 566 of which were analyzed with T2 relaxometry and DTI. The T2 values were as follows: subgroup A, 55.8±4.4 ms; B, 48.5±6.9 ms; C, 45.8±8.7 ms (p <0.050). The T2 values for the healthy controls of the subgroups A, B, and C were >120 ms, 90-100 ms, and 70 ms, respectively (p <0.001). Control subgroup A had higher T2 values and AF/NP ratios than subgroups B and C; the AF values were not significantly different. Control subgroup B had higher T2 values and AF/NP ratios than subgroup C but lower FA (NP). Conclusions: FA maps of the AF/NP ratio and T2 values of NP are potential microstructure biomarkers of normal and degenerating discs and can help detect early degeneration using a predictive disc health score on a continuous scale. [ABSTRACT FROM AUTHOR]