Pearls and pitfalls in emergency CT neuroangiography through the lens of bias and error.

Computed tomography angiography (CTA) of the head and neck is central in emergency department (ED) evaluation of clinically suspected acute stroke and intracranial hemorrhage. Timely and accurate detection of acute findings is crucial for best clinical outcomes; missed or delayed diagnosis can be devastating. Our pictorial essay presents twelve CTA cases that provided significant diagnostic dilemmas to on-call trainees while reviewing current bias and error classifications in radiology. Among others, we discuss anchoring, automation, framing, satisfaction of search, scout neglect and zebra-retreat bias. Each imaging vignette depicts a potential diagnostic "pitfall" while introducing types of cognitive bias/error before concluding with a concrete "pearl" for CTA interpretation. We believe that familiarity with bias and error is particularly important in the ED setting where high case volume, high acuity and radiologist fatigue intersect. Particular attention to personal cognitive biases and these potential CTA pitfalls may help emergency radiologists transition from habit-driven pattern recognition to analytical thinking, ultimately improving diagnostic decision making.

Pyriform sinus rupture caused by blunt trauma.

Hypopharyngeal perforation (HP) is a potentially life-threatening condition most associated with iatrogenic injury and foreign body impaction. Additionally, a number of cases of posterior HP have been reported following blunt cervical trauma. We present a case of a construction accident causing lateral hypopharyngeal rupture. Visceral perforation was initially diagnosed on computed tomography (CT) imaging and managed conservatively. We speculate this region may be particularly vulnerable to injury due to an anatomic transition in adjacent fascial support. A review of 29 prior cases suggests that this may be the first reported case of blunt trauma causing rupture of the pyriform sinus. However, significant heterogeneity exists in diagnostic approach. Radiography and CT are rapid, sensitive modalities for suggesting pharyngeal perforation, while fluoroscopy and endoscopy can better assess injury size and location and monitor resolution. Early radiologic recognition of hypopharyngeal injury is essential to initiate appropriate treatment. In certain cases, including our own, both the presence and specific location of perforation may be identified on initial CT images.

A Systematic Review of the Existing Prostate Imaging Reporting and Data System Version 2 (PI-RADSv2) Literature and Subset Meta-Analysis of PI-RADSv2 Categories Stratified by Gleason Scores.

OBJECTIVE: The objective of this study was to quantitatively and qualitatively assess the methodologic heterogeneity of the current Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) literature and estimate the proportions of Gleason scores (GSs) diagnosed across PI-RADSv2 categories. MATERIALS AND METHODS: This study was a systematic review and meta-analysis and was performed in concordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only English-language studies and studies published before April 1, 2018, were assessed. The primary outcome of the meta-analysis was the estimated percentage of patients with GS ≥ 3 + 4 within each individual PI-RADSv2 score. We calculated the pooled estimates and 95% CIs on the basis of a random-effects model using the meta-analysis routine of Stata (version 13.1). RESULTS: Our search revealed 434 titles, and 59 of these studies were selected. These studies were remarkable for their technical and terminological diverseness. Thirteen studies had sufficient data to be included in the meta-analysis. The prevalence of ≥ GS 3 + 4 in lesions assigned a PI-RADSv2 score of 3 or higher was approximately 45%. Lesions assigned PI-RADSv2 scores 1 or 2, 3, 4, and 5 represented high-grade disease in approximately 6%, 12%, 48%, and 72% of patients. CONCLUSION: The data available in the literature are highly heterogeneous and challenging to analyze because of variations in terminology, patient cohort selection, criteria, imaging parameters, and reference standards. In spite of this heterogeneity, our meta-analysis shows that PI-RADSv2 has good sensitivity when a score of ≥ 3 is considered as a positive test.

Ferromagnetic sand: A possible MRI hazard.

While the ferromagnetic properties of metallic objects, implantable medical devices, and cosmetics are well known, sand is not generally considered a consequential substance. Beaches in specific geographic regions, including the San Francisco Bay Area, have a propensity for ferromagnetic sand because of their geologic history. We describe a case in which ferromagnetic sand in a patient's hair coated the magnetic resonance imaging (MRI) scanner bore and caused significant imaging artifact, fortunately with no harm to the patient. We recommend that MRI facilities in areas where ferromagnetic sand is found consider educating technologists and screening patients for recent black sand exposure prior to scanning.

Neuroimaging findings in Pallister-Killian syndrome.

Pallister-Killian syndrome (PKS) is a rare chromosomal duplication disorder caused by additional copies of the short arm of chromosome 12 (12p). Clinically PKS is characterized by craniofacial dysmorphism with neonatal frontotemporal alopecia, hypertelorism, and low-set ears as well as kyphoscoliosis, severe intellectual disability, epilepsy, and abnormal muscle tone. Comprehensive high-resolution brain MR findings of PKS in childhood have not been previously illustrated in the medical literature. We present detailed neuroimaging findings from a child with PKS and thoroughly review previously reported structural brain abnormalities in this patient population. MRI abnormalities common to PKS include cerebral volume loss, malformations of cortical development, corpus callosum dysgenesis, white matter disease, and craniofacial malformations. In our patient, new findings of perisylvian with occipital polymicrogyria, vermian dysplasia, brachium pontis signal abnormality, dural anomalies, and unilateral atlas assimilation were noted. Micrencephaly and cortical dysplasia provide a likely explanation for severe intellectual disability and epilepsy in this patient population.