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.

Clinical PET/CT utilization during the COVID-19 pandemic: initial experience at Yale University.

OBJECTIVE: To determine temporal changes in PET/CT utilization during the COVID-19 pandemic and examine the impact of epidemiologic, demographic and oncologic factors on PET/CT utilization. METHODS: Clinical PET-CT utilization between 1 January 2020 and 15 June 2020 at a tertiary academic center was assessed using change-point-detection (CPD) analysis. COVID-19 epidemiologic trend was obtained from Connecticut Department of Public Health records. Demographic and oncologic data were gathered from electronic medical records and PET-CT scans by four reviewers in consensus. RESULTS: A total of 1685 cases were reviewed. CPD analysis identified five distinct phases of PET-CT utilization during COVID-19, with a sharp decline and a gradual recovery. There was a 62.5% decline in case volumes at the nadir. These changes correlated with COVID-19 epidemiologic changes in the state of Connecticut, with a negative correlation between COVID-19 cases and PET-CT utilization (τ = -0.54; P value < 0.001). Statistically significant differences in age, race, cancer type and current and prior scan positivity were observed in these five phases. A greater percentage of young patients and minorities were scanned during the pandemic relative to baseline. PET/CT scanning was less impacted for hematologic malignancies than for solid cancers, with less profound decline and better recovery. DISCUSSION: PET-CT cancer imaging was vulnerable to the COVID-19 pandemic at our institution. Epidemiologic, demographic and oncologic factors affected PET-CT utilization.

Diagnostic Value of CT of Chest, Abdomen, and Pelvis in Patients With Solitary and Multiple Brain Lesions.

OBJECTIVE. A common goal in patients with newly discovered brain lesions is to determine if the lesions are primary malignant brain neoplasms, metastases, or benign entities. Such patients often undergo CT of the chest, abdomen, and pelvis (CT CAP) to identify a primary neoplasm that may have metastasized to the brain. The aim of this study is to determine the frequency of finding a primary cancer on CT CAP. MATERIALS AND METHODS. A large academic hospital imaging database was searched for cases of new intracranial lesions with subsequent CT CAP performed for metastatic workup. The frequency of primary neoplasms diagnosed in the chest versus abdominal and pelvic portions of CT scans was determined in patients with newly identified intraaxial and extraaxial brain lesions. Lesion characteristics were recorded including size, number, and the presence of enhancement and hemorrhage. Ancillary signs of an abdominopelvic neoplasm were also recorded. RESULTS. A total of 227 of 287 (79%) cases of newly discovered intracranial lesions were malignant (primary or metastatic) and 60 (21%) were benign. Of the 227 malignant cases, 136 (60%) were primary brain neoplasms and 91 (40%) were brain metastases, and 68 of the 91 (75%) lung primary. Chest CT (CTC) identified a primary neoplasm in 65 of 287 (23%) cases; 63 of those 65 (96%) neoplasms arose in the lungs. CT of the abdomen and pelvis (CTAP) identified a primary neoplasm in only 3 of 287 (1%) cases. In 26 cases in which the intracranial lesions did not enhance, only one was metastatic. CONCLUSION. In patients with newly discovered brain lesions, CTC is warranted, but CTAP is unlikely to be useful in patients without ancillary signs of abdominopelvic neoplasm.

Frustration and Emotional Regulation in Nonsyndromic Craniosynostosis: A Functional Magnetic Resonance Imaging Study.

BACKGROUND: Nonsyndromic craniosynostosis may manifest with complex behavioral, attentional, and emotional sequelae. The authors characterized higher level brain connectivity in adolescent nonsyndromic craniosynostosis patients in response to emotional frustration. METHODS: Surgically corrected patients older than 9 years with nonsyndromic craniosynostosis were age/sex/handedness matched to controls. Patients participated in a "go/no-go" task, structured as win/lose/recovery paradigms. BioImage Suite was used to analyze whole-brain intrinsic connectivity between tasks with cluster-corrected group-level t maps. A value of p < 0.05 was significant. RESULTS: Seven unilateral coronal (average age, 12.2 years), six metopic (average age, 11.5 years), and controls were included. Unilateral coronal had worse emotional regulation scores on the Behavior Rating Inventory of Executive Function survey (p = 0.065) and performed poorly on the go/no-go task (p < 0.001). Metopic had four regions of interest, with the majority having decreased activity compared with controls, and few differences between tasks. Unilateral coronal patients had 11 regions of interest; the majority decreased during the win and lose conditions, but all increased during the recovery condition. Metopic patients had decreased blood oxygenation level- dependent signal in the posterior cingulate (p = 0.017) and middle temporal gyrus (p = 0.042). Unilateral coronal had decreased signal in the posterior cingulate (p = 0.023), middle temporal gyrus (p = 0.027), and thalamus (p = 0.033), but increased signal in the cuneus (p = 0.009) and cerebellum (p = 0.009). Right unilateral coronal, but not metopic/controls, had increased right brain activity in the caudate (p = 0.030), thalamus (p = 0.011), temporal lobe (p = 0.012), and cerebellum (p = 0.029). CONCLUSIONS: Unilateral coronal patients may have emotional dysregulation in response to frustration, whereas metopic patients may have attenuated emotional reactions. Evidence of right unilateral coronal brain laterality suggests that the area of suture fusion may contribute to the mechanism of dysfunction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

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.