Susceptibility-weighted imaging in differentiating bilateral medial thalamic venous and arterial infarcts

Bilateral medial thalamic infarcts may be due to thrombosis of internal cerebral veins or occlusion of artery of Percheron. Conventional MR imaging is often not helpful in differentiating the two. We discuss two cases in whom susceptibility-weighted imaging, including phase images contributed in demonstrating the thrombosed or patent internal cerebral veins

Clinical utility of susceptibility-weighted imaging in vascular diseases of the brain

Susceptibility-weighted imaging (SWI) is a rapidly evolving technique that utilizes both the magnitude and phase information to obtain valuable information about susceptibility changes between tissues. SWI is very sensitive to the paramagnetic effects of deoxyhemoglobin. SWI plays an important role in the diagnostic evaluation and management of acute stroke. In addition, it also plays an important role in the imaging of patients with chronic arterial occlusion and in understanding the effects of chronic infarction, like incomplete infarction and cortical laminar necrosis. The hemodynamic status and oxygen extraction fraction can also be evaluated. SWI is useful in evaluating cerebral venous sinus thrombosis by demonstrating the hemorrhagic venous infarction and thrombus in the sinus and the cortical veins, as well as secondary phenomena like venous stasis in the form of engorged cortical and transmedullary veins and collateral slow flow. Low-flow vascular malformations that are not visualized well on conventional sequences are depicted in exquisite detail along with the venous components on SWI. SWI is used for evaluating cavernomas, developmental venous anomalies, telangiactasias, dural arteriovenous fistulas and the various components of arteriovenous malformations. It has also evolved as a noninvasive technique for evaluating various anomalies of the venous system without administering contrast. Vasculopathies and vasculitis are associated with cerebral microbleeds which are detected on SWI. On the basis of the additional information provided by SWI, it can be included in the routine brain imaging protocol

Rosette forming glioneuronal tumor of the fourth ventricle in squash cytology smear

Rosette forming glioneuronal tumor (RGNT) is a recently recognized and extremely rare glioneuronal tumor occurring in the fourth ventricle. It is crucial for the cytopathologist to be aware of this entity as it can be easily mistaken for more common neoplasms occurring at this site. We present here the cytology of such a rare case of RGNT that was misdiagnosed as ependymoma. The varying cytological features of this entity, as well as the common diagnostic difficulties encountered in cytology, are highlighted in this report

Spontaneous intracranial hypo and hypertensions: An imaging review

Cerebrospinal fluid (CSF) pressure changes can manifest as either intracranial hypertension or hypotension. The idiopathic forms are largely under or misdiagnosed. Spontaneous intracranial hypotension occurs due to reduced CSF pressure usually as a result of a spontaneous dural tear. Idiopathic intracranial hypertension (IIH) is a syndrome of elevated intracranial tension without hydrocephalus or mass lesions and with normal CSF composition. Neuroimaging plays an important role in excluding secondary causes of raised intracranial tension. As the clinical presentation is varied, imaging may also help the clinician in arriving at the diagnosis of IIH with the help of a few specific signs. In this review, we attempt to compile the salient magnetic resonance imaging findings in these two conditions. Careful observation of these findings may help in early accurate diagnosis and to provide appropriate early treatment

Dysphagia Aortica: Diagnostic Dilemma and Therapeutic Paradigm

Objective: Intrinsic esophageal pathologies constitute prime cause for dysphagia clinically. However, thoracic esophageal domain is prone to extrinsic compression by various vascular afflictions including aneurysms with attendant therapeutic challenges. Herein, we present a case series of dysphagia aortica with emphasis on its appropriate management option based on grade of dysphagia. Methods: Patients who presented to the vascular division of our tertiary care referral institute between January 2014 and October 2015 with dysphagia due to extrinsic esophageal compression by aneurysmal thoracic aorta form the basis for this report. Prior to referral, all patients were evaluated elsewhere to rule out intrinsic causes and computed tomography angiogram performed delineating aortic aneurysm in four patients and penetrating aortic ulcer in one. Patient cohort included one female and four male patients whose age ranged from 40 to 68 years, with a median of 62 years. Left posterolateral thoracotomy provided access to an aneurysm which was repaired using interposition polyester graft in four patients. Due to severe comorbidities which precluded open surgery, one patient who presented with mild dysphagia was managed by endovascular stent graft repair. Results: Degree of dysphagia was assessed between grades 0 and 4 as in literature. All patients, including four open conventional and one endovascular, recovered well and left hospital totally symptom free. Conclusion: Dysphagia due to vascular diseases in the thoracic domain is an uncommon clinical entity. Patients with thoracic aortic aneurysm presenting with severe dysphagia deserve open surgical repair to provide optimal symptomatic relief in addition to saving life. The state-of-the-art endovascular stent grafting may be considered in very elderly patient having severe comorbidities presenting with mild dysphagia

The making of indigenous vascular prosthesis

Background & objectives: Vascular illnesses are on the rise in India, due to increase in lifestyle diseases and demographic transition, requiring intervention to save life, organ or limbs using vascular prosthesis. The aim of this study was to develop indigenous large diameter vascular graft for treatment of patients with vascular pathologies. Methods: The South India Textile Research Association, at Coimbatore, Tamil Nadu, India, developed seamless woven polyester (Polyethylene terephthalate) graft at its research wing. Further characterization and testing followed by clinical trials were conducted at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Fifteen in vivo experiments were carried out in 1992-1994 in pigs as animal model. Controlled (phase I) clinical trial in ten patients was performed along with control graft. Thereafter, phase II trial involved 22 patients who underwent multi-centre clinical trial in four centres across India. Results: Laboratory testing showed that polyester graft was non-toxic, non-leeching and non-haemolytic with preserved long-term quality, further confirming in pigs by implanting in thoracic aorta, comparable to control Dacron grafts. Perigraft incorporation and smooth neointima formation which are prime features of excellent healing characteristics, were noted at explantation at planned intervals. Subsequently in the phase I and II clinical trials, all patients had excellent recovery without mortality or device-related adverse events. Patients receiving the test graft were followed up for 10 and 5 years, respectively. Serial clinical, duplex scans and CT angiograms performed periodically confirmed excellent graft performance. Interpretation & conclusions: Indigenously developed Chitra vascular graft was comparable to commercially available Dacron graft, ready for clinical use at affordable cost to patients as against costly imported grafts