School-age children are more skeptical of inaccurate robots than adults.

We expect children to learn new words, skills, and ideas from various technologies. When learning from humans, children prefer people who are reliable and trustworthy, yet children also forgive people's occasional mistakes. Are the dynamics of children learning from technologies, which can also be unreliable, similar to learning from humans? We tackle this question by focusing on early childhood, an age at which children are expected to master foundational academic skills. In this project, 168 4-7-year-old children (Study 1) and 168 adults (Study 2) played a word-guessing game with either a human or robot. The partner first gave a sequence of correct answers, but then followed this with a sequence of wrong answers, with a reaction following each one. Reactions varied by condition, either expressing an accident, an accident marked with an apology, or an unhelpful intention. We found that older children were less trusting than both younger children and adults and were even more skeptical after errors. Trust decreased most rapidly when errors were intentional, but only children (and especially older children) outright rejected help from intentionally unhelpful partners. As an exception to this general trend, older children maintained their trust for longer when a robot (but not a human) apologized for its mistake. Our work suggests that educational technology design cannot be one size fits all but rather must account for developmental changes in children's learning goals.

Utilization of the track embolization technique to improve the safety of percutaneous lung biopsy and/or fiducial marker placement.

PURPOSE: The purpose of the study was to describe and present outcomes of the track embolization technique with absorbable hemostat gelatin powder during percutaneous computed tomography (CT)-guided lung biopsy and/or fiducial marker placement versus the standard of care (no track embolization) in an attempt to decrease rates of pneumothorax (PTX), chest tube placement, hemorrhage and/or complications, and average cost per patient. MATERIALS AND METHODS: An institutional review board-approved, case-control, retrospective study was performed in which 125 consecutive patients who underwent track embolization were compared with 124 consecutive controls at one institution. For subjects in whom the track embolization technique was utilized, it was performed passively through a coaxial needle as it was removed. All procedures were performed by one of three attending interventional radiologists. For each group, medical records and procedure images were reviewed for PTX occurring postprocedure, PTX requiring chest tube placement, and occurrence of minor or major complication and/or hemorrhage. Comparison was made with published complication rates, and a cost-per-patient analysis was performed. Statistical analysis was performed utilizing Fisher's Exact Test. RESULTS: In track embolization cases versus controls, there were statistically significant reduction in PTX (8.8% vs. 21%; P=.007) and reduction in PTX requiring chest tube placement (4% vs. 8.1%; P=.195). This compares favorably to previously published rates of PTX and chest tube placement of 8%-64% and 1.6%-17%, respectively. None of the pneumothoraces occurring at time of needle placement increased in size with use of the track embolization technique. There were no major complications (including neurological sequela) in the track embolization group. In track embolization cases versus controls, there was a statistically significant reduction in both the rate of major hemorrhage (0% vs. 4%; P=.029) and average cost per patient ($262.40 vs. $352.07; P=.044). CONCLUSIONS: CT-guided percutaneous lung biopsy and/or fiducial marker placement were safer utilizing the track embolization technique during trocar removal. In addition, this technique was cost effective in the study population.

CT of inferior vena cava filters: normal presentations and potential complications.

With massive pulmonary embolism (PE) being the first or second leading cause of unexpected death in adults, protection against PE is critical in appropriately selected patients. The use of inferior vena cava (IVC) filters has increased over the years, paralleling the increased detection of deep venous thrombosis (DVT) and PE by improved and more available imaging techniques. The use of IVC filters has become very common as an alternative and/or as a supplement to anticoagulation, and these filters are often seen on routine abdominal CT, including in the emergency setting; therefore, knowledge of the normal spectrum of findings of IVC filters by the radiologist on CT is critical. Additionally, CT can be used specifically to identify complications related to IVC filters, and CT may alternatively demonstrate IVC filter-related problems which are not specifically anticipated clinically. With multiple available IVC filters on the US market, and even more available outside of the USA, it is important for the emergency and the general radiologist to recognize the different models and various appearances and positioning on CT, as well as their potential complications. These complications may be related to venous access, but also include thrombosis related to the filter, filter migration and penetration, and problems associated with filter deployment. With the increasing number of inferior vena cava filters placed and their duration within patients increasing over time, it is critical for emergency and other radiologists to be aware of these findings on CT.

Evolving role of computed tomographic colonography in colon cancer screening and diagnosis.

Computed tomographic colonography (CTC) is a relatively new imaging modality for the examination of patients for colorectal polyps and cancer. It has been validated in its accuracy for the detection of colon cancer and larger polyps (more than likely premalignant). CTC, however, is not widely accepted as a primary screening modality in the United States at present by many third-party payers, including Medicare, and its exact role in screening is evolving. Moreover, there has been opposition to incorporating CTC as an accepted screening instrument, especially by gastroenterologists. Heretofore, optical colonoscopy has been the mainstay in this screening. We discuss these issues and the continuing controversies concerning CTC.

Radiology-Pathology Conference: Mature teratoma arising from an intra-abdominal undescended testis in a 7-month-old infant.

We report a rare case of an intra-abdominal testicular mature teratoma in a 7-month-old male infant presenting with a palpable abdominal mass and unilateral undescended testis. We describe the pathology, clinical presentation, and imaging findings of this entity. Clinical features accompanied by characteristic radiologic findings guide a provisional diagnosis that is confirmed by histologic analysis following surgical removal of the tumor. The pathogenesis and radiologic findings of testicular mature teratomas in the prepubertal population share many similarities to that of mature ovarian teratomas commonly seen in females of reproductive age. Awareness of this entity will permit the radiologist to suggest timely diagnosis and intervention when presented with a similar case.

Pancreatic cystic neoplasms.

Pancreatic cysts include inflammatory lesions, low-grade neoplasms, and malignant neoplasms. Cystic neoplasms may prompt investigation because of symptoms such as abdominal pain, distension, jaundice, or nausea, but they are usually incidentally discovered. In the older literature, pseudocysts related to acute and chronic pancreatitis accounted for the majority of pancreatic cysts, but it is difficult to differentiate pancreatic cystic neoplasms from pseudocysts even with high-resolution modalities including computed tomography (CT) and magnetic resonance imaging (MRI) scans. Additionally, the more recent literature has shown that small pancreatic cystic lesions are relatively common as incidental findings on cross-sectional imaging examinations that are performed for other reasons, typically in older patients without prior episodes of pancreatitis; these are often low-grade mucinous lesions or occasionally epithelial cysts. Endoscopic ultrasound with fine-needle aspiration has emerged as a prime modality in delineating such cystic lesions. There has been an exponential increase in the more recent literature regarding pancreatic cystic lesions. The purpose of this review article is to provide a concise overview of these pancreatic cystic lesions.