The changing landscape in epilepsy imaging: Unmasking subtle and unique entities.

Dramatic changes have occurred recently in the field of epilepsy, including a fundamental shift in the etiology of epileptogenic substrates found at surgery. Hippocampal sclerosis is no longer the most common etiology found at epilepsy surgery and this decrease has been associated with an increase in the incidence of focal cortical dysplasia and encephaloceles. Significant advances have been made in molecular biology and genetics underlying the basis of malformations of cortical development, and our ability to detect epileptogenic abnormalities with MR imaging has markedly improved. This article begins with a discussion of these trends and reviews imaging techniques essential for detecting of subtle epilepsy findings. Representative examples of subtle imaging findings are presented, which are often overlooked but should not be missed. These include temporal lobe encephaloceles, malformations of cortical development (and especially focal cortical dysplasia), hippocampal sclerosis, hippocampal malformation (also known as HIMAL), ulegyria, autoimmune encephalitis, and Rasmussen's encephalitis. Recent findings on the pathophysiology and genetic underpinnings of several causes of localization-related epilepsy are incorporated. For instance, it has been recently found that focal cortical dysplasia IIb, tuberous sclerosis, hemimegalencephaly, and gangliogliomas are all the result of mutations of the mTOR pathway for cell growth.

Emergent Neuroimaging During Pregnancy and the Postpartum Period.

Acute neurologic emergencies in pregnancy often require neuroimaging to guide diagnosis and treatment. Implementation of a patient-centered care model in radiology can alleviate a patient's stress, reinforce appropriate imaging workup, improve patient satisfaction, and lead to improved outcomes. The authors present the evaluation, differential diagnosis, and recommended imaging protocols for the three most common acute neurologic symptoms in pregnancy and the postpartum period: headache, seizure, and focal neurologic deficits. With the patient's symptoms as a reference point, the referring physician in consultation with the radiologist can effectively implement the optimal imaging procedures.

The vomiting neonate: a review of the ACR appropriateness criteria and ultrasound's role in the workup of such patients.

Ultrasound (US) plays a central role in the diagnostic imaging workup for infantile vomiting. This paper reviews the major causes of vomiting in the first months of life and the use of US and other modalities for their imaging assessment. The differential diagnostic possibilities are reviewed by examining 3 clinical scenarios of bilious vomiting during the first days of life, nonbilious vomiting since birth, and projectile vomiting first occurring after several weeks of life. These are the 3 scenarios that were used for the American College of Radiology (ACR) Appropriateness Criteria for Vomiting in Infants up to 3 Months of Age.

The sonographic double-track sign: not pathognomonic for hypertrophic pyloric stenosis; can be seen in pylorospasm.

OBJECTIVE: The "double-track" sign has previously been reported as specific for hypertrophic pyloric stenosis when noted on an upper gastrointestinal series. The sign has been noted on sonographic examinations as well. We sought to determine whether this sign can also be seen in cases of pylorospasm diagnosed by sonography, proving it not to be pathognomonic for hypertrophic pyloric stenosis. METHODS: The data obtained prospectively from 91 consecutive patients studied between 1999 and 2002 by sonography for projectile vomiting were retrospectively reviewed. Cases with diagnoses of hypertrophic pyloric stenosis or pylorospasm were reviewed for the imaging finding of the double-track sign. RESULTS: Thirty-seven patients had a sonographic diagnosis of hypertrophic pyloric stenosis that was confirmed surgically. Twenty-six (70.2%) showed a sonographic double-track sign. Thirty-four patients had a sonographic diagnosis of pylorospasm that was confirmed by close clinical follow-up. Eighteen (52.9%) showed a sonographic double-track sign. CONCLUSIONS: The sonographic double-track sign can be seen in cases of pylorospasm as well as hypertrophic pyloric stenosis. It is not pathognomonic for hypertrophic pyloric stenosis.

Approach to the educational opportunities provided by variant anatomy, illustrated by discussion of a duplicated inferior vena cava.

Variant anatomy recognized during routine cadaveric dissection in the first year of medical school offers great learning potential by allowing students to gain enhanced understanding of an array of important subjects. It provides a framework for reviewing common morphology and embryogenesis of the structure in question, and through the help of appropriate faculty, yields insight into the potential medical, radiologic, and surgical implications. The frequency of clinically important anatomic variation is high enough to allow the gross anatomy laboratory to serve as an excellent teaching platform in this regard. Through anatomy, the student is introduced to the concept of patient individuality, and to the individualization of medical and surgical therapies. Recently, one of the variations encountered in our lab was a duplicated inferior vena cava. We describe our approach to such findings through a systematic discussion of the anatomy and embryology, as well as the radiologic and clinical correlates.