Anupama Chandrasekharan

Neonatal brain MRI segmentation

This review paper focuses on the neonatal brain segmentation algorithms in the literature. It provides an overview of clinical magnetic resonance imaging (MRI) of the newborn brain and the challenges in automated tissue classification of neonatal brain MRI. It presents a complete survey of the existing segmentation methods and their salient features. The different approaches are categorized into intracranial and brain tissue segmentation algorithms based on their level of tissue classification. Further, the brain tissue segmentation techniques are grouped based on their atlas usage into atlas-based, augmented atlas-based and atlas-free methods. In addition, the research gaps and lacunae in literature are also identified.

Ultrasound versus MRI in the diagnosis of fetal head and trunk anomalies

Objective. To compare antenatal sonography and magnetic resonance (MR) imaging (MRI) in the diagnosis of fetal head and trunk anomalies. Methods. Forty pregnant women with fetal anomalies on ultrasound (US) examination underwent MRI. The MR examination was done by a radiologist who was provided with the US data. The MR images were then read by one of the two radiologists who were blinded to the US data. They were however told that the region of interest was (1) head–neck or (2) trunk or (3) both. Antenatal US and MRI findings were compared with postnatal diagnosis. Postnatal evaluation included plain radiograph, US, computed tomography, MRI, surgery, physical evaluation and autopsy. Results. Sixty anomalies were detected in the 40 women studied. This included 36 central nervous system (CNS), 7 thoracic, 7 gastrointestinal, 8 genitourinary and 2 face–neck anomalies. In the evaluation of CNS and thoracic anomalies, more number of confident diagnoses could be obtained by MRI when compared with that by US. In the detection of gastrointestinal and genitourinary anomalies, there was no significant difference between the two modalities. Conclusion. More number of confident diagnoses could be obtained by MRI when compared with that by US, in the evaluation of fetal CNS and thoracic anomalies. MRI can be used in complex fetal anomalies as a supplementary tool following US.

Case Report: Congenital infiltrating lipomatosis of face

Congenital infiltrating lipomatosis of the face is a rare condition characterized by diffuse fatty infiltration of the facial soft tissues. There may be muscle involvement along with associated bony hyperplasia. It is a type of lipomatous tumor that is congenital in origin; it is rare and seen usually in childhood. We recently saw an 11-year-old girl with this condition. She presented with a swelling of the right side of the face that had been present since birth; there were typical findings on plain radiographs, CT, and MRI. The patient underwent cosmetic surgery. Histopathological examination showed mature adipocytes without any capsule.

Unilateral agenesis of internal carotid artery with intercavernous anastomosis: a rare case report.

Unilateral agenesis of internal carotid artery (ICA) with intercavernous anastomosis is a rare congenital anomaly. We present a case of a 25-year-old female with 2-month history of holocranial headache. Neurological examination was unremarkable. Magnetic resonance imaging (MRI) with magnetic resonance angiography (MRA) showed absence of left ICA with an abnormal intercavernous vessel in the sella. Computed tomography (CT) showed absence of the left carotid canal. Doppler ultrasonography (USG) showed high resistance flow in the left common carotid artery (CCA). Since no hemorrhage or aneurysm was seen, patient was managed conservatively and is on regular follow-up. Based on our knowledge, this is the first case to demonstrate the features of unilateral agenesis of ICA with intercavernous anastomosis in X-ray, Doppler USG, CT, and MRI scans of the brain.

Case report: Antenatal MRI diagnosis of esophageal duplication cyst

Esophageal duplication cysts are classified as a subgroup of foregut duplication cysts. They are very rare and are predominantly detected in children. Antenatal detection is very rare. We report a case of an esophageal duplication cyst that was accurately identified antenatally by USG and MRI.

Role of MR cisternography in the diagnosis of cerebrospinal fluid rhinorrhoea with diagnostic nasal endoscopy and surgical correlation

Objectives : To study the usefulness and accuracy of MR cisternography as noninvasive study in the diagnosis of cerebrospinal fluid (CSF) fistula with diagnostic sinonasal endoscopy and surgical correlation. Material and Methods: Twenty four patients with clinically suspected CSF rhinorrhoea were examined for CSF fistula with MR cisternography. The MR imaging technique included 3mm thin T2 weighted coronal and sagittal sections using Fast spin echo. In addition 1.5mm thin T2 weighted coronal sections were also obtained using CISS (Constructive Interference in Steady State) sequence. MR findings were correlated with diagnostic sinonasal endoscopy and surgical findings. Results : MR cisternography demonstrated the presence of fistula in 17 patients, absence of fistula in seven patients. Out of 17 patients with fistula, the diagnosis could be confirmed in 14 patients by diagnostic sinonasal endoscopy/surgery. Out of the seven patients without fistula, there was positive correlation in six patients when they were followed up clinically and by diagnostic nasal endoscopy. However in one patient, fistula was demonstrated on CT cisternography and was confirmed on sinonasal endoscopic surgery. The accuracy, sensitivity of MR cisternography was 96, 94% respectively. Conclusion : MR cisternography is a useful and accurate noninvasive study in localizing the site and extent of CSF fistula.

Automatic segmentation of neonatal brain magnetic resonance images

This paper provides an overview of magnetic resonance imaging of the neonatal brain, presents the challenges involved in segmenting the neonatal brain images and reviews the existing techniques for automatic segmentation, including atlas-based probabilistic segmentations and morphology based brain segmentation. It compares the various methods in practice and highlights their limitations, particularly the inadequacies in segmenting the myelinated portions of the brain. It also proposes a new approach to overcome these shortcomings.

Decubital ischemic fasciitis presenting in an unusual location

Decubital ischemic fasciitis, also called atypical decubital fibroplasia, is a distinctive fibroplasia occurring in nonambulatory older patients who are confined to bed or wheelchair-bound. These lesions are seen in the subcutaneous plane at pressure points or bony prominences. We present a case of ischemic fasciitis in a 68-year-old male patient who presented with a hard swelling in the middle third of the posterolateral aspect of the right leg, which is an unusual site for ischemic fasciitis.

Magnetic resonance imaging findings in viral encephalitis: A pictorial essay

Viral encephalitis by definition is the result of human virus affecting the brain and sparing the meninges. The other nervous system manifestations are meningitis, meningoencephalitis, encephalomyelitis, and encephalomyeloradiculitis. Encephalitis can involve any age group from children to old people. The severity of the disease depends on the viral agent and the host immune system. The patient can present with fever, headache, seizure, neurological deficit, or altered sensorium. Laboratory investigations, imaging, and cerebrospinal fluid analysis are crucial in the diagnosis of encephalitis. Magnetic resonance imaging (MRI) findings may be nonspecific or specific and plays a major role in the diagnosis of encephalitis and predicting the possible cause. This pictorial essay reviews the MRI findings of common types of viral encephalitis.

MRI at term equivalent age for predicting long term neuro-developmental outcome in preterm infants - A cohort study

Abstract Purpose: Preterm infants are at increased risk of adverse neurodevelopmental outcome (NDO). Cranial ultrasound has limited predictability. The purpose of the study is to evaluate whether magnetic resonance imaging (MRI) done at term equivalent age (TEA) predicts NDO at 18–22 months of corrected gestational age (CGA). Materials and methods: This cohort study of preterm infants born at ≤32 weeks of gestation and/or birth weight <1500 grams between April 2011 and August 2012 was conducted in a tertiary care institute in India. MRI done at TEA was reported using objective scoring. NDO at 18–22-month CGA was assessed using Bayley Scale of Infant Development (BSID) version III. Composite score (CS) < 85 in motor, language, or cognition domain was taken as adverse NDO. Association between individual MRI subscores and NDO was evaluated using multiple linear regressions by backward elimination method. Validity of MRI abnormality in predicting adverse NDO was assessed. Results: Out of 94 infants who had MRI at TEA, 56 (60%) underwent BSID III. Mean gestational age was 29.8 ± 2.1 weeks. Median CS of all domains was lower with higher total MRI score. Predictive accuracy for various subscores ranged from 55 to 73%. By multiple regression analysis, signal abnormality was associated with motor delay (β −8.4; p .02) and cystic white matter (WM) changes with motor delay (β −7.3; p .003) and cognitive delay (β −6.1; p .005). Conclusions: Although specificity and negative predictive value were moderate to high across all subscores in MRI to predict the NDO, the accuracy has been only low to moderate, which limits its use as sole predictor.