Quantitative Automated Segmentation of Lipiodol Deposits on Cone-Beam CT Imaging Acquired during Transarterial Chemoembolization for Liver Tumors: A Deep Learning Approach

PurposeTo show that a deep learning (DL)–based, automated model for Lipiodol (Guerbet Pharmaceuticals, Paris, France) segmentation on cone-beam computed tomography (CT) after conventional transarterial chemoembolization performs closer to the “ground truth segmentation” than a conventional thresholding-based model.Materials and MethodsThis post hoc analysis included 36 patients with a diagnosis of hepatocellular carcinoma or other solid liver tumors who underwent conventional transarterial chemoembolization with an intraprocedural cone-beam CT. Semiautomatic segmentation of Lipiodol was obtained. Subsequently, a convolutional U-net model was used to output a binary mask that predicted Lipiodol deposition. A threshold value of signal intensity on cone-beam CT was used to obtain a Lipiodol mask for comparison. The dice similarity coefficient (DSC), mean squared error (MSE), center of mass (CM), and fractional volume ratios for both masks were obtained by comparing them to the ground truth (radiologist-segmented Lipiodol deposits) to obtain accuracy metrics for the 2 masks. These results were used to compare the model versus the threshold technique.ResultsFor all metrics, the U-net outperformed the threshold technique: DSC (0.65 ± 0.17 vs 0.45 ± 0.22, P < .001) and MSE (125.53 ± 107.36 vs 185.98 ± 93.82, P = .005). The difference between the CM predicted and the actual CM was 15.31 mm ± 14.63 versus 31.34 mm ± 30.24 (P < .001), with lesser distance indicating higher accuracy. The fraction of volume present ([predicted Lipiodol volume]/[ground truth Lipiodol volume]) was 1.22 ± 0.84 versus 2.58 ± 3.52 (P = .048) for the current model’s prediction and threshold technique, respectively.ConclusionsThis study showed that a DL framework could detect Lipiodol in cone-beam CT imaging and was capable of outperforming the conventionally used thresholding technique over several metrics. Further optimization will allow for more accurate, quantitative predictions of Lipiodol depositions intraprocedurally.     

基于病案的教学查房结合PACS在影像科医师培养中的应用

目的探讨在影像科医师培养中,基于病案(CBL)的教学查房结合医学影像存储与通讯系统(PACS)对医师影像诊断能力培养的价值。方法对2018年在北京大学第三医院放射科轮转CT的41名培训医师,应用PACS对其进行CBL教学查房,对照组为2017年轮转CT的39名培训医师(未进行CBL教学)。从PACS随机抽取每名医师书写的10份报告(报告时间为培训最后1个月),对开展CBL教学前后培训医师的报告书写质量评分并计算优良率。评分标准包括病灶征象描述全面准确、报告内容条理清晰规范、诊断结论逻辑清晰合理、能回答临床提出的问题、提出的下一步诊疗建议合理准确以及无漏诊。同时采用调查问卷的方式评价培训医师对CBL教学查房的主观感受,包括全面系统的认识疾病、提高临床思维能力、读片能力和学习兴趣、PACS对学习的帮助5方面,采用百分比表示。结果1)进行CBL教学查房后,培训医师报告质量评分提高(P<0.01)。2)培训医师对调查问卷5方面满意率分别为90.2%、68.3%、80.5%、75.6%和80.5%。结论应用PACS进行CBL教学查房是培养影像科医师诊断能力的有效方法。     

“T” is for “transgender”: an analysis of children’s picture books featuring transgender protagonists and narrators

ABSTRACT

This project examined 55 picture books featuring transgender, gender expansive or genderqueer protagonists or narrators published between 2008 and 2018. The purpose of the study was to determine how this genre of children’s literature supports and challenges four gender assumptions: the gender binary, gender essentialism, sex/gender congruency and gender stability. Additionally, this critical analysis explored misgendering within this genre and themes of social rejection and acceptance. Protagonists and narrators were permitted a degree of gender nonconformity, however, the majority of picture books missed opportunities for a more complete exploration of gender possibilities.     

Stroop interference associated with efficient reading fluency and prelexical orthographic processing

The Stroop Color–Word Test involves a dynamic interplay between reading and executive functioning that elicits intuitions of word reading automaticity. One such intuition is that strong reading skills (i.e., more automatized word reading) play a disruptive role within the test, contributing to Stroop interference. However, evidence has accumulated that challenges this intuition. The present study examined associations among Stroop interference, reading skills (i.e., isolated word identification, grapheme-to-phoneme mapping, phonemic awareness, reading fluency) measured on standardized tests, and orthographic skills measured on experimental computerized tasks. Among university students (N = 152), correlational analyses showed greater Stroop interference to be associated with (a) relatively low scores on all standardized reading tests, and (b) longer response latencies on orthographic tasks. Hierarchical regression demonstrated that reading fluency and prelexical orthographic processing predicted unique and significant variance in Stroop interference beyond baseline rapid naming. Results suggest that strong reading skills, including orthographic processing, play a supportive role in resolving Stroop interference.     

Category fluency in schizophrenia: opposing effects of negative and positive symptoms?

Introduction: Category fluency is associated with speed-, executive- and semantic impairments in schizphrenia. It has traditionally been linked to negative symptoms, whereas the relation to positive symptoms is mixed. Associations to the consensus negative, positive and disorganisation factors have not been analysed before.

Methods: Animal fluency was administered to 81 patients with schizophrenia. Measures of overall performance and applied strategies were analysed in relation to the Wallwork five-factor PANSS-model.

Results: Negative and disorganisation symptoms were negatively related to overall fluency performance. Positive symptoms were positively related to overall performance when controlling for disorganisation symptoms. Negative symptoms were related to fewer switches, less repetitions, less single animals intrusions, and both less rare and common animals. Positive symptoms were related to more effective retrieval of sub-category exemplars following a sub-category title, whereas there were no relation between symptoms and exemplars when the title was not retrieved. The Beta values of negative and positive symptoms were opposite.

Conclusion: This is the first study showing that positive symptoms are related to increased fluency performance when disorganisation is controlled for. Like previous studies, negative symptoms were found to depress fluency. Strategy measures indicated that negative symptoms predispose for rigidity, whereas positive symptoms facilitate more efficient associative pathways.     

Word onset phonetic properties and motor artifacts in speech production EEG recordings

Electrophysiological research using verbal response paradigms faces the problem of muscle artifacts that occur during speech production or in the period preceding articulation. In this context, this paper has two related aims. The first is to show how the nature of the first phoneme influences the alignment of the ERPs. The second is to further characterize the EEG signal around the onset of articulation, both in temporal and frequency domains. Participants were asked to name aloud pictures of common objects. We applied microstate analyses and time‐frequency transformations of ERPs locked to vocal onset to compare the EEG signal between voiced and unvoiced labial plosive word onset consonants. We found a delay of about 40 ms in the set of stable topographic patterns for /b/ relative to /p/ onset words. A similar shift was observed in the power increase of gamma oscillations (30–50 Hz), which had an earlier onset for /p/ trials (～150 ms before vocal onset). This 40‐ms shift is consistent with the length of the voiced proportion of the acoustic signal prior to the release of the closure in the vocal responses. These results demonstrate that phonetic features are an important parameter affecting response‐locked ERPs, and hence that the onset of the acoustic energy may not be an optimal trigger for synchronizing the EEG activity to the response in vocal paradigms. The indexes explored in this study provide a step forward in the characterization of muscle‐related artifacts in electrophysiological studies of speech and language production.     

Phonological facilitation effects on naming latencies and viewing times during noun and verb naming in agrammatic and anomic aphasia

Background: Phonological priming has been shown to facilitate naming in individuals with aphasia, as well as healthy speakers, resulting in faster naming latencies. However, the mechanisms of phonological facilitation (PF) in aphasia remain unclear.

Aims: Within discrete vs. interactive models of lexical access, this study examined whether PF occurs via the sub-lexical or lexical route during noun and verb naming in agrammatic and anomic aphasia.

Methods & Procedures: Thirteen participants with agrammatic aphasia and 10 participants with anomic aphasia and their young and age-matched controls (n = 20/each) were tested. Experiment 1 examined noun and verb naming deficit patterns in an off-line confrontation naming task. Experiment 2 examined PF effects on naming both word categories using eyetracking priming paradigm.

Outcomes & Results: Results of Experiment 1 showed greater naming difficulty for verbs than for nouns in the agrammatic group, with no difference between the two word categories in the anomic group. For both participant groups, errors were dominated by semantic paraphasias, indicating impaired lexical selection. In the phonological priming task (Experiment 2), young and age-matched control groups showed PF in both noun and verb naming. Interestingly, the agrammatic group showed PF when naming verbs, but not nouns, whereas the anomic group showed PF for nouns only.

Conclusions: Consistent with lexically mediated PF in interactive models of lexical access, selective PF for different word categories in our agrammatic and anomic groups suggest that phonological primes facilitate lexical selection via feedback activation, resulting in greater PF for more difficult (i.e., verbs in agrammatic and possibly nouns in anomic group) lexical items.