In this article, we first review some aspects of functional magnetic resonance imaging (fMRI) paradigm designing for major cognitive functions by using stimulus delivery systems like Cogent, E-Prime, Presentation, etc., along with their technical aspects. We also review the stimulus presentation possibilities (block, event-related) for visual or auditory paradigms and their advantage in both clinical and research setting. The second part mainly focus on various fMRI data post-processing tools such as Statistical Parametric Mapping (SPM) and Brain Voyager, and discuss the particulars of various preprocessing steps involved (realignment, co-registration, normalization, smoothing) in these software and also the statistical analysis principles of General Linear Modeling for final interpretation of a functional activation result.

Surgical techniques have emerged as a viable therapeutic option in patients with drug refractory epilepsy. Pre-surgical evaluation of epilepsy requires a comprehensive, multiparametric, and multimodal approach for precise localization of the epileptogenic focus. Various non-invasive techniques are available at the disposal of the treating physician to detect the epileptogenic focus, which include electroencephalography (EEG), video-EEG, magnetic resonance imaging (MRI), functional MRI including blood oxygen level dependent (BOLD) techniques, single photon emission tomography (SPECT), and ¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Currently, non-invasive high-resolution MR imaging techniques play pivotal roles in the preoperative detection of the seizure focus, and represent the foundation for successful epilepsy surgery. BOLD functional magnetic resonance imaging (fMRI) maps allow for precise localization of the eloquent cortex in relation to the seizure focus. This review article focuses on the clinical utility of BOLD (fMRI) in the pre-surgical work-up of epilepsy patients.

Evaluating language has been a long-standing application in functional magnetic resonance imaging (fMRI) studies, both in research and clinical circumstances, and still provides challenges. Localization of eloquent areas is important in neurosurgical cases, so that there is least possible damage to these areas during surgery, maintaining their function postoperatively, therefore providing good quality of life to the patient. Preoperative fMRI study is a non-invasive tool to localize the eloquent areas, including language, with other traditional methods generally used being invasive and at times perilous. In this article, we describe methods and various paradigms to study the language areas, in clinical neurosurgical cases, along with illustrations of cases from our institute.

Objectives: The current study used functional MRI (fMRI) to obtain a comprehensive understanding of the neural network underlying visual word recognition in Hindi/Devanagari, an alphasyllabic - partly alphabetic and partly syllabic Indian writing system on which little research has hitherto been carried out. Materials and Methods: Sixteen (5F, 11M) neurologically healthy, native Hindi/Devanagari readers aged 21 to 50 named aloud 240 Devanagari words which were either visually linear - had no diacritics or consonant ligatures above or below central plane of text, e.g. फल, वाहन, or nonlinear - had at least one diacritic and/or ligature, e.g. फूल, किरण, and which further included 120 words each of high and low frequency. Words were presented in alternating high and low frequency blocks of 10 words each at 2s/word in a block design, with linear and nonlinear words in separate runs. Word reading accuracy was manually coded, while fMRI images were acquired on a 3T scanner with an 8-channel head-coil, using a T2*-weighted EPI sequence (TR/TE = 2s/35ms). Results: After ensuring high word naming accuracy (M = 97.6%, SD = 2.3), fMRI data analyses (at FDR P < 0.005) revealed that reading Devanagari words elicited robust activations in bilateral occipito-temporal, inferior frontal and precentral regions as well as both cerebellar hemispheres. Other common areas of activation included left inferior parietal and right superior temporal cortices. Primary differences seen between nonlinear and linear word reading networks were in the right temporal areas and cerebellum. Conclusion: Distinct from alphabetic scripts, which are linear in their spatial organization, and recruit a primarily left-lateralized network for word reading, our results revealed a bilateral reading network for Devanagari. We attribute the additional activations in Devanagari to increased visual processing demands arising from the complex visuospatial arrangement of symbols in this ancient script.

Background: Functional magnetic resonance imaging (fMRI), a non-invasive technique with high spatial resolution and blood oxygen level dependent (BOLD) contrast, has been applied to localize and map cognitive functions in the clinical condition of chronic intractable epilepsy. Purpose: fMRI was used to map the language and memory network in patients of chronic intractable epilepsy pre- and post-surgery. Materials and Methods: After obtaining approval from the institutional ethics committee, six patients with intractable epilepsy with an equal number of age-matched controls were recruited in the study. A 1.5 T MR scanner with 12-channel head coil, integrated with audio-visual fMRI accessories was used. Echo planar imaging sequence was used for BOLD studies. There were two sessions in TLE (pre- and post-surgery). Results: In TLE patients, BOLD activation increased post-surgery in comparison of pre-surgery in inferior frontal gyrus (IFG), middle frontal gyrus (MFG), and superior temporal gyrus (STG), during semantic lexical, judgment, comprehension, and semantic memory tasks. Conclusion: Functional MRI is useful to study the basic concepts related to language and memory lateralization in TLE and guide surgeons for preservation of important brain areas during ATLR. This will help in understanding future directions for the diagnosis and treatment of such disease.

Extrapontine myelinolysis, a fairly common metabolic disorder, is associated with neurological complications. Central pontine and extrapontine myelinolysis are commonly recognized with rapid correction of sodium. Myelinolysis, however, has rarely been described with hypernatremia. We report a rare case of post-partum hypernatremic encephalopathy associated with serum sodium levels as high as 200 mEq/l on presentation. Although the serum sodium levels were brought down gradually, subsequent imaging showed progression of demyelination and deterioration of the neurological status.

Bilateral duplicated origin of V-1 segment of vertebral arteries is an extremely rare vascular variant and only two such cases have been reported so far. Presence of this vascular abnormality was observed incidentally in a 36-year-old male patient, with a complaint of dizziness, evaluated by multidetector row computed tomography (CT) angiography. Two limbs of the right vertebral artery arose from the right subclavian artery and fused to form a single vessel at the interval between fourth and fifth cervical vertebrae, which entered the foramen transversarium of fourth cervical vertebra. On the left side, the medial limb originated directly from the arch of aorta and the lateral limb from the left subclavian artery, and both united at the interval between fifth and sixth cervical vertebrae to form a single vessel which entered the foramen transversarium of fifth cervical vertebra. No other cerebrovascular pathology like aneurysm, fenestration, dissection, and stenosis was detected, which could be correlated with the symptoms of the patient. This rare congenital vascular anomaly has diagnostic and therapeutic implications in any intervention involving the vertebral artery.

Aim: To investigate variations in superior thyroid artery (STA) based on digital subtraction angiography (DSA). Materials and Methods: Twenty five angiography studies of 15 pts performed between June 2010 and December 2012 were retrospectively evaluated. These patients underwent DSA of the head and neck region as a part of their superselective neoadjuvant intra-arterial chemotherapy protocol for treatment of laryngeal and hypopharyngeal cancers. Depending upon the location of the tumor, unilateral or bilateral arteriograms of common carotid artery (CCA), external carotid artery (ECA), and STA were performed. Arteriograms were evaluated for the site of origin and branching pattern of STA. STA anatomy was ascribed to one of the three branching patterns. Results: A total of 25 angiograms were evaluated, including 14 right and 11 left. On the right side, STA was noted to arise from ECA in 10 (71.5%), bifurcation of CCA in 3 (21.5%), and CCA in 1 (7%) patient. Left STA was seen to arise from ECA in 8 (72.5%), bifurcation of CCA in 2 (18.5%), and internal carotid artery (ICA) in 1 (9%) patient. Type III branching pattern (non-bifurcation, non-trifurcation) was found to be the most frequent (52%). Infrahyoid branch was found to be the most consistent in terms of its origin from STA. Conclusions: Origin of STA is predictable, arising from ECA in more than 70% cases. Branching pattern of STA, following origin from ECA, is, however, highly variable. Knowledge concerning the origin and branching pattern of STA is essential in enhancing precision and decreasing morbidity related to the surgical and interventional radiological head and neck procedures.

We report a case of post traumatic impacted intranasal wooden foreign body in a 16 year old boy, which was undetected on Computed Tomography in the acute stage. Intranasal wooden foreign body may be missed on CT in the acute stage because of apparent air attenuation of the foreign body and lack of contrast with the surrounding intranasal air. Radiologists need to be aware of the CT imaging appearances of wood in various stages for early detection and management.

Myositis ossificans is a rare cause of trismus. We present a case of pseudomalignant myositis ossificans involving medial pterygoid, lateral pterygoid, and temporalis muscles. Patient presented with gross limitation in mouth opening. There was no history of trauma. Computed tomography (CT) images revealed a bone density mass located in the region of medial and lateral pterygoid muscles on the right and temporalis muscle on the left. Magnetic resonance imaging (MRI) showed similar findings. Radiological diagnosis was pseudomalignant myositis ossificans. The masses were resected and histopathologic examination confirmed the above diagnosis. This report describes the characteristic CT and MRI features. The unique feature of this case is the absence of history of trauma with involvement of multiple masticatory muscles, which, to the best of our knowledge, has not been reported before.

Transarterial chemoembolization (TACE) is the well-known treatment for hepatocellular carcinoma. Multiple digital subtraction angiography (DSA) acquisitions in different projections are required to identify difficult arterial feeders. Moreover, the tell-tale tumor blush can be obscured by proximity to lung base, small size of lesion, and breathing artifacts. C-arm CT is a revolutionary advancement in the intervention radiology suite that allows acquisition of data which can be reformatted in multiple planes and volume rendered incorporating both soft tissue and vascular information like multidetector computed tomography (MDCT). These images acquired during the TACE procedure can provide critical inputs for achieving a safe and effective therapy. This case series aims to illustrate the utility of C-arm CT in solving specific problems encountered while performing TACE.

Hyperreactio luteinalis is a rare entity in which there is bilateral, benign, functional multicystic ovarian enlargement during pregnancy, which is most commonly seen in third trimester. This condition is usually innocuous and does not need any specific treatment. However, many a times, it is mistaken for ovarian malignancy and inadvertently operated upon. This is a case report of a 24-year-old female with a partial molar pregnancy associated with hyperreactio luteinalis who was followed up for regression of the same and normalization of beta human chorionic gonadotropin (hCG) levels.

Most urethral strictures arise from iatrogenic, traumatic, or inflammatory causes. We report the familial occurrence of a congenital bulbar urethral stricture in two brothers. Retrograde and voiding cystourethrography was performed. A Cobb's collar was diagnosed after radiological and endoscopic evaluation in both cases and was successfully managed with urethroplasty. Cobb's collar is a rarely recognized cause of a membranous stricture of bulbar urethra that can lead to several urinary problems. In cases of adolescent and young adults presenting with symptoms of progressive urinary obstruction and enuresis with or without urinary tract infection, Cobb's collar can be seen as a minor constriction in the bulbar urethra, but is not frequently symptomatic, and the familial occurrence of such a stricture is even rarer.