Predicting Survival Using Whole-Liver MRI Radiomics in Patients with Hepatocellular Carcinoma After TACE Refractoriness.

PURPOSE: To develop a model based on whole-liver radiomics features of pre-treatment enhanced MRI for predicting the prognosis of hepatocellular carcinoma (HCC) patients undergoing continued transarterial chemoembolization (TACE) after TACE-resistance. MATERIALS AND METHODS: Data from 111 TACE-resistant HCC patients between January 2014 and March 2018 were retrospectively collected. At a ratio of 7:3, patients were randomly assigned to developing and validation cohorts. The whole-liver were manually segmented, and the radiomics signature was extracted. The tumor and liver radiomics score (TLrad-score) was calculated. Models were trained by machine learning algorithms and their predictive efficacies were compared. RESULTS: Tumor stage, tumor burden, body mass index, alpha-fetoprotein, and vascular invasion were revealed as independent risk factors for survival. The model trained by Random Forest algorithms based on tumor burden, whole-liver radiomics signature, and clinical features had the highest predictive efficacy, with c-index values of 0.85 and 0.80 and areas under the ROC curve of 0.96 and 0.83 in the developing cohort and validation cohort, respectively. In the high-rad-score group (TLrad-score > - 0.34), the median overall survival (mOS) was significantly shorter than in the low-rad-score group (17 m vs. 37 m, p < 0.001). A shorter mOS was observed in patients with high tumor burden compared to those with low tumor burden (14 m vs. 29 m, p = 0.007). CONCLUSION: The combined radiomics model from whole-liver signatures may effectively predict survival for HCC patients continuing TACE after TACE refractoriness. The TLrad-score and tumor burden are potential prognostic markers for TACE therapy following TACE-resistance.

Diabetes mellitus and the risk of urolithiasis: a meta-analysis of observational studies.

Diabetes mellitus (DM) might increase the risk of urolithiasis, but the results were inconsistent. Hence, we conducted a meta-analysis to assess the association between DM and the risk of urolithiasis. We searched PubMed, Embase, and Cochrane Library to identify the relevant observational studies up to November 2014. Reference lists of retrieved articles were also reviewed. Summary relative risks (RRs) and corresponding 95% confidence intervals (CIs) were used to estimate the association between DM and the risk of urolithiasis. We identified 3 case-control studies and 4 cohort studies regarding DM and the risk of urolithiasis, involving 247,531 participants. Analyses of all studies showed that DM was associated with an increased risk of urolithiasis (RR=1.24, 95% CI: 1.14-1.35). There was heterogeneity among studies (p=0.027, I2=57.9%). The association between DM and the risk of urolithiasis was not significantly differed by gender, but this association was inconsistent in the North American and Asian populations. When restricting the analysis to studies that had adjusted for body mass index (n=2) or hypertension (n=3), the RRs were 1.46 (95% CI: 1.03-2.06) and 1.22 (95% CI: 1.01-1.48), respectively. There was no significant publication bias (p=0.96 for Egger's regression asymmetry test). Our study provided evidence that there was a significant direct association of DM and the risk of urolithiasis. However, this finding was based on the observational studies, and more well-designed randomized controlled trials were needed.

[Analysis and experimental validation of signal-to-noise for limb imaging spectrometer].

Limb imaging spectrometer is an important new remote sensor for research and application. Signal-to-noise ratio (SNR) is one of the key parameters to quantitatively evaluate the image quality and radiometric performance of an imaging spectrometer. The estimation and testing of SNR are very important for developing an imaging spectrometer. From the perspectives of radiative transmission and energy conversion, the SNR model is proposed, and the SNR equation of dispersive-type limb imaging spectrometer is derived, and the SNR values under several observing conditions for an limb imaging spectrometer prototype developed are theoretically evaluated based on atmospheric radiative transfer code MODTRAN 4.0. The results show that the SNR of the prototype under typical viewing geometry is not less than 8. As experimental validation, SNR testing was performed using an internally illuminated integrating sphere, and the experimental results have proved the correctness of this theoretical model.

[Development of soft X-ray and vacuum ultraviolet spectrum sources].

The soft X-ray and vacuum ultraviolet sources developed in CIOMP are presented. The wall-stabilized argon arc source with spectrum stability and repeatability of +/-0.3% is applied to the calibration of spectrum intensity distribution of the vacuum ultraviolet instruments as an absolute standard source. The Penning source, duobplasma source and hollow cathode source are able to produce atomic and ionic line spectra as a wavelength standard source, which covers a few nanometers to several tens nanometers with spectrum radiation stability and repeatability of +/-1.0%. In particular, the low debris laser produced plasma source with liquid aerosol spray target recently developed can emit stronger soft X-ray for soft X-ray lithography and metrology, which has a transfer efficiency as high as 0.75%/2pi x sr/2% bandwidth.

[Application of BaSO4 diffuser plate in 250-400 nm spectral radiance calibration].

Sprayed BaSO4 diffuser plate is the most Lambertian surface actually used in spectral radiance calibration known by now. Its hemispheric reflectance and Bi-directional Reflectance Distribution Functions (BRDF) were measured in the experiment. Its diffuse characteristics were compared with Lambertian surface. In order to calibrate spectral radiance more accurately, the small variation of diffuser's BRDF with scattered angles and the nonuniformity of spectral irradiance on diffuser surface illuminated by the standard lamp should be considered. By integrating the radiation flux reflected by the element area and that entering the entrance slit within the viewing area of spectrometer, the measured spectral radiance can be calculated. Furthermore, the spectral radiance of Lambertian surface whose BRDF was derived from hemispheric reflectance was compared with that from the average of the measured BRDF.

[The depolarization characteristic of quartz depolarizer in UV-VUV spectral region].

The quartz depolarizer consisting of two wedge-shaped quartz crystals was designed based on the Lyot depolarizer. The quartz depolarizer is used to reduce the polarization response of spectral instruments. The residual degree of polarization of the quartz depolarizer was derived by the method of matrix optics, so the variation regularity of its depolarization characteristic was analysed concerning its center thickness and the status of the incident radiation in the UV-VUV spectral range. Its depolarization effect was obvious for the radiation with some spectral bandwidth. Also, the depolarization characteristic of the quartz depolarizer was studied experimentally with 1-meter Seya-Namioka UV-VUV spectrometer, using LiF crystals as the polarizer and analyzer. The residual degree of polarization of the quartz depolarizer was less than 1%. Both the theoretical analysis and experimental results show that the quartz depolarizer we designed is appropriate to the spectral measurement with high accuracy.

[Results of unilateral lung volume reduction surgery in twenty-five patients with chronic obstructive pulmonary disease].

OBJECTIVE: To evaluate the effectiveness of unilateral lung volume reduction surgery (LVRS) in patients with chronic obstructive pulmonary disease (COPD). METHODS: The follow-up data of 25 patients with COPD who had underwent unilateral LVRS between January 1996 to December 2002 in department of thoracic surgery, China-Japan friendship hospital were analyzed retrospectively. The operative target was determined by pre-operative CT and pulmonary ventilation-perfusion (V/Q) scintigraphy. LVRS was performed in 21 patients through video assisted thoracoscopy surgery (VATS) or VATS with adjuvant small lateral thoracotomy. In 4 patients LVRS was performed through posterolateral thoracotomy. Destroyed pulmonary tissue was resected by liner stapler or Endo GIA. To evaluate the effectiveness of unilateral LVRS, the changing of dyspnea score, pulmonary function and the quality of life were analyzed. RESULTS: The postoperative follow-up interval range was 2 years. The mean postoperative FEV(1) increased by (35 +/- 9)%, and six minute walking distance (6MWD) increased by (88 +/- 22)%. For dyspnea score, among 16 patients with a preoperative grade of IV, 4 patients improved to grade I, 12 improved to grade II; among 9 patients with a preoperative grade of V, 1 improved to grade I, 1 improved to grade II, 4 improved to grade III, and the other 3 improved to grade IV. Karnofsky score increased by (44 +/- 10) in average. One and two year survival rates was 96% and 92%, respectively. There was no perioperative death in this group, and the total postoperative morbidity was 32%. CONCLUSIONS: Unilateral LVRS shows significant clinical benefits for the majority of patients with COPD. It is associated with lower operative mortality and morbidity, and has a wide range of indications. The key points of the operation are to resect dysfunctional lung tissues as much as possible and to prevent pulmonary air leak. Preoperative and postoperative breathing training plays a very important role in the postoperative recovering of lung function.

[Polarization characteristic of LiF polarizer at UV-VUV spectral range].

A method of determinating the degree of polarization of grating, polarizer and analyzer at some wavelength is introduced. The degrees of polarization of LiF polarizers were determined with 1 m Seya-Namioka monochromator by this way. The source is hollow cathode source. The degrees of polarization of two, four and eight LiF plates were measured at 120, 149.2, 174.2, 214.2, 235.0, 300 and 340 nm. The theoretical and experimental reults were consistent within the error. The angular extinction dependence of the LiF polarizer and analyzer was measured at VUV wavelengths. The results showed the expected cosine square dependence, so a high degree of polarization was indeed produced. Also, the LiF polarizer was used to measure the polarization characters of the Al + MgF2 reflectance and the absolute grating efficiency at both parallel and perpendicular to their incident plane.

[Polarization characteristic of Al + MgF2 film at VUV].

Polarization characteristic of Al + MgF2 is researched theoretically and experimentally. According to the theory of electromagnetism, the reflectance perpendicular and parallel to the incident plane of Al + MgF2 is calculated in the way of matrix optics. The effect of incident conditions and thickness of MgF2 is considered on the reflectance of Al + MgF2 coatings. The MgF2 not only prevents the oxidation of aluminum but also increases the reflectance of Al + MgF2 by interference. The polarization of Al + MgF2 is analyzed using the concept of ratio of extinction based on above mentioned calculations. The polarization character of Al + MgF2 and single Al coating is compared. The reflectances perpendicular and parallel to the incident plane of Al + MgF2 film are measured at VUV range, using LiF polarizer as a VUV polarizer. So the polarization character of Al + MgF2 is researched experimentally. Both theoretical and experimental results of the polarization character of Al + MgF2 are coincident.