Prediction of Central Lymph Node Metastasis in cN0 Papillary Thyroid Carcinoma by CT Radiomics.

RATIONALE AND OBJECTIVES: To explore the feasibility of the preoperative prediction of pathological central lymph node metastasis (CLNM) status in patients with negative clinical lymph node (cN0) papillary thyroid carcinoma (PTC) using a computed tomography (CT) radiomics signature. MATERIALS AND METHODS: A total of 97 PTC cN0 nodules with CLNM pathology data (pN0, with CLNM, n = 59; pN1, without CLNM, n = 38) in 85 patients were divided into a training set (n = 69) and a validation set (n = 28). For each lesion, 321 radiomic features were extracted from nonenhanced, arterial and venous phase CT images. Minimum redundancy and maximum relevance and the least absolute shrinkage and selection operator were used to find the most important features with which to develop a radiomics signature in the training set. The performance of the radiomics signature was evaluated by receiver operating characteristic curves, calibration curves and decision curve analysis . RESULTS: Three nonzero the least absolute shrinkage and selection operator coefficient features were selected for radiomics signature construction. The radiomics signature for distinguishing the pN0 and pN1 groups achieved areas under the curve of 0.79 (95% CI 0.67, 0.91) in the training set and 0.77 (95% CI 0.55, 0.99) in the validation set. The calibration curves demonstrated good agreement between the radiomics score-predicted probability and the pathological results in the two sets (p= 0.399, p = 0.191). The decision curve analysis curves showed that the model was clinically useful. CONCLUSION: This radiomic signature could be helpful to predict CLNM status in cN0 PTC patients.

Frequency-dependent neural activity in primary angle-closure glaucoma.

OBJECTIVE: In this study, we aimed to investigate the frequency-dependent spontaneous neural activity in primary angle-closure glaucoma (PACG) using the amplitude of low-frequency fluctuations (ALFF) method. PATIENTS AND METHODS: In total, 52 PACG individuals (24 males and 28 females) and 52 normal-sighted controls (NS; 24 males and 28 females) who were closely matched in age, sex, and education underwent resting-state magnetic resonance imaging scans. A repeated-measures ANOVA and post hoc two-sample t-tests were conducted to analyze the different ALFF values in two different frequency bands (slow-4, 0.027-0.073 Hz and slow-5, 0.010-0.027 Hz) between the two groups. Pearson's correlation analysis was conducted to reveal the relationship between the mean ALFF values and clinical variables in the PACG group. RESULTS: Compared to the NS group, the PACG group had high ALFF values in the right inferior occipital gyrus and low ALFF values in the left middle occipital gyrus, left precentral gyrus, and left postcentral gyrus in the slow-4 band. The PACG group had high ALFF values in the right inferior occipital gyrus and low ALFF values in the left inferior parietal lobule, left postcentral gyrus, and right precentral/postcentral gyrus in the slow-5 band. Specifically, we found that the abnormal ALFF values in the bilateral posterior cingulate gyrus and bilateral precuneus were higher in the slow-4 than in the slow-5 band, whereas ALFF in the bilateral frontal lobe, right fusiform, and right cerebellum posterior lobe were higher in the slow-5 than in the slow-4 band. The greater mean ALFF values of the right inferior occipital gyrus were associated with smaller retinal nerve fiber layer thickness and greater visual fields in PACG group in the slow-4 band. CONCLUSION: Our results highlighted that individuals in the PACG group showed abnormal spontaneous neural activities in the visual cortices, sensorimotor cortices, frontal lobe, frontoparietal network, and default mode network at two frequency bands, which might indicate impaired vision and cognition and emotion function in PACG individuals. These findings offer important insight into the understanding of the neural mechanism of PACG.

The mode of yearly biological cycle of malignant growth of hepatocellular carcinoma on computed tomography.

OBJECTIVE: To detect the mode of yearly biological cycle of malignant biological behavior of hepatocellular carcinoma (HCC). METHODS: Twenty-one kinds of CT signs reflecting various degrees of malignant biological behavior were determined. A total of 360 patients were collected by random sampling of 30 patients each month. CT signs of each patient were fitted in corresponding group of yearly cyclic data respectively by cosine curves and analysed in terms of sequence characteristics (cosinor). RESULTS: With a 95% confidence, 10 CT signs showed biological rhythm (P<0.05). The acrophase of CT features for highly-invasive growth concentrated between -60 degree and -120 degree from March to April. For low-invasive growth, however, the CT features were relatively low and concentrated between -180 degrees and -270 degrees from July to September. No acrophase was shown between -120 degrees and -180 degrees from May to June, and between -270 degrees and -330 degrees from October to November. CONCLUSION: Between CT signs of the highly-invasive and those of low-invasive growth of HCC, a sequential difference in biological cycles can be observed.

[Comparison of the yearly cycle cosine curve imitative parameters of the clinical features of liver cancer at different longitude and latitude].

OBJECTIVE: To explore whether there exists coincidence of the most appearing time of clinical features of liver cancer at different longitude and latitude, according to the law of field equation and the theory of warpage of space time by Einstein. METHODS: Three regions with different longitude and latitude were selected randomly and sampled. There were 36 items altogether, including 12 clinical items, which were used to imitate the yearly cycle cosine curve. The acorphases and the ratioes of amplitudes and means were compared to justifying whether they were in the same range. RESULTS: All the acorphases of 36 items appeared between -90.1degrees to -207.5 degrees (from april to july), existing in one third of the same range, in which 13 items occurred rhythmly (P<0.05). The image acorphases of liver cancer at the early and middle stage and gamma-glutamyl transpeptidase acorphase appeared between -98.5 degrees to -148.2 degrees (from april to may), in which 5 items occurred rhythmly (P<0.05). CONCLUSION: It is the same mode of the yearly biologcal cycle for liver cancer malignant growth within the most appearing time (from april to july). It will increase the detecting rate of liver cancer at the early and middle stage during this time (especially from april to may).