Preoperative prediction of lymphovascular and perineural invasion in gastric cancer using spectral computed tomography imaging and machine learning.

BACKGROUND: Lymphovascular invasion (LVI) and perineural invasion (PNI) are important prognostic factors for gastric cancer (GC) that indicate an increased risk of metastasis and poor outcomes. Accurate preoperative prediction of LVI/PNI status could help clinicians identify high-risk patients and guide treatment decisions. However, prior models using conventional computed tomography (CT) images to predict LVI or PNI separately have had limited accuracy. Spectral CT provides quantitative enhancement parameters that may better capture tumor invasion. We hypothesized that a predictive model combining clinical and spectral CT parameters would accurately preoperatively predict LVI/PNI status in GC patients. AIM: To develop and test a machine learning model that fuses spectral CT parameters and clinical indicators to predict LVI/PNI status accurately. METHODS: This study used a retrospective dataset involving 257 GC patients (training cohort, n = 172; validation cohort, n = 85). First, several clinical indicators, including serum tumor markers, CT-TN stages and CT-detected extramural vein invasion (CT-EMVI), were extracted, as were quantitative spectral CT parameters from the delineated tumor regions. Next, a two-step feature selection approach using correlation-based methods and information gain ranking inside a 10-fold cross-validation loop was utilized to select informative clinical and spectral CT parameters. A logistic regression (LR)-based nomogram model was subsequently constructed to predict LVI/PNI status, and its performance was evaluated using the area under the receiver operating characteristic curve (AUC). RESULTS: In both the training and validation cohorts, CT T3-4 stage, CT-N positive status, and CT-EMVI positive status are more prevalent in the LVI/PNI-positive group and these differences are statistically significant (P < 0.05). LR analysis of the training group showed preoperative CT-T stage, CT-EMVI, single-energy CT values of 70 keV of venous phase (VP-70 keV), and the ratio of standardized iodine concentration of equilibrium phase (EP-NIC) were independent influencing factors. The AUCs of VP-70 keV and EP-NIC were 0.888 and 0.824, respectively, which were slightly greater than those of CT-T and CT-EMVI (AUC = 0.793, 0.762). The nomogram combining CT-T stage, CT-EMVI, VP-70 keV and EP-NIC yielded AUCs of 0.918 (0.866-0.954) and 0.874 (0.784-0.936) in the training and validation cohorts, which are significantly higher than using each of single independent factors (P < 0.05). CONCLUSION: The study found that using portal venous and EP spectral CT parameters allows effective preoperative detection of LVI/PNI in GC, with accuracy boosted by integrating clinical markers.

Characterizing Sensorimotor-Related Area Abnormalities in Amyotrophic Lateral Sclerosis: An Intravoxel Incoherent Motion Magnetic Resonance Imaging Study.

RATIONALE AND OBJECTIVES: To investigate the microperfusion and water molecule diffusion alterations in sensorimotor-related areas in amyotrophic lateral sclerosis (ALS) using intravoxel incoherent motion (IVIM) magnetic resonance imaging. MATERIALS AND METHODS: IVIM data were obtained from 43 ALS patients and 31 controls. This study employed the revised ALS Functional Rating Scale (ALSFRS-R) in evaluating disease severity. IVIM-derived metrics were calculated, including diffusion coefficient (D), pseudo-diffusion coefficient, and perfusion fraction. Conventional apparent diffusion coefficient was also computed. Atlas-based analysis was conducted to detect between-group difference in these metrics in sensorimotor-related gray/white matter areas. Spearman correlation analysis was employed to establish correlation between various metrics and ALSFRS-R. RESULTS: ALS patients had perfusion fraction (× 10-3) reduction in the left presupplementary motor area (60.72 ± 16.15 vs. 71.15 ± 12.98, p = 0.016), right presupplementary motor area (61.35 ± 17.02 vs. 72.18 ± 14.22, p = 0.016), left supplementary motor area (55.73 ± 12.29 vs. 64.12 ± 9.17, p = 0.015), and right supplementary motor area (56.53 ± 11.93 vs. 63.67 ± 10.03, p = 0.020). Patients showed D (× 10-6 mm2/s) increase in a white matter tract projecting to the right ventral premotor cortex (714.20 ± 39.75 vs. 691.01 ± 24.53, p = 0.034). A negative correlation between D of right ventral premotor cortex tract and ALSFRS-R score was observed (r = -0.316, p = 0.039). CONCLUSION: These findings suggest aberrant microperfusion and water molecule diffusion in the sensorimotor-related areas in ALS patients, which are associated with motor impairment in ALS.

Incidental pulmonary embolism in suspected stroke patients undergoing carotid CT angiography.

PURPOSE: The purpose of this study was to investigate the prevalence of incidental pulmonary embolism (IPE) in suspected stroke patients receiving carotid computed tomography angiography (CTA) and its characteristics. MATERIALS AND METHODS: A total of 4873 cases receiving carotid CTA between January 2013 and December 2016 were retrospectively reassessed by one radiologist. Patients with previous or suspected PE were excluded. The remaining prior contrast-enhanced carotid CTA studies were regarded as a "potentially incidental" IPE when a filling defect was found in one or more pulmonary arteries and subjected to the other two thoracic radiologists independently for reviewing and assessing for characteristics of the IPE and the image quality of the PE. The differences were noted between inpatients and outpatients in prevalence of IPE. Characteristics of the patients with IPE were also studied in terms of gender, age, as well as clinical indication. RESULTS: The prevalence of IPE among these suspected stroke patients was 0.8% on carotid CT angiography, and 24 (96%) of all IPEs had not been previously diagnosed by the original reporting radiologists. Most of the IPEs were at the lobar or segmental levels, single and in right upper lobe of pulmonary arteries. In most of the cases, the reviewing radiologists judged the contrast bolus as good. The outpatient group had a lower percentage of patients with IPE when compared with the inpatient counterpart (p = 0.024). The prevalence of IPE in patients with suspected stroke was higher with the increasing of age (p = 0.013). CONCLUSIONS: IPE can occur in suspected stroke patients on carotid CT angiography, and most of them have been previously neglected in clinical practice. Radiologists should check the higher pulmonary arterial vasculature carefully on the contrast-enhanced carotid CTA scans.

[Study on the release and mechanism of carbon nanotubes loaded with verapamil hydrochloride in vitro].

OBJECTIVE: The aim of this study was to load Verapamil Hydrochloride to carboxylated multi-walled carbon nanotubes( c-CNTs) and discuss the mechanism of drug release which could act as an effective basis for c-MWNTs used as drug carriers of controlled and sustained release delivery system. METHODS: Raw CNTs were treated with mixed strong acid to obtain c-CNTs. Raman, IR, SEM and HR-TEM were used to characterize the CNTs and investigate the loading sites for drugs. The release behavior of the drug delivery system in vitro and the release model were studied. RESULTS: The raw CNTs were successfully grafted with carboxyl group by acid treatment. The water-soluble ability of c-CNTs was greatly improved. The length of c-CNTs was 200-300nm. Meanwhile, the ends of c-CNTs were opened. The results of the drug loading experiment showed that the more adding drugs, the larger loading content of drugs. Most of the drugs were loaded into the inner pores of c-CNTs when adding drugs was no more than 0.1 as quantity as c-CNTs. As the quantity of adding drugs increased, the drugs were loaded both in the inner pores and on the out-wall of c-CNTs. The release results in vitro showed release mechanism had something with the quantity of adding drugs. CONCLUSION: C-CNTs can be used as carriers of sustained and controlled release delivery system. Ideal release behavior of drugs can be achieved by choosing appropriate formula.

[Comparative study of the effects of Gypsum Fibrosum and Gypsum Fibrosum Preparatum in promoting granulation].

OBJECTIVE: To investigate the effects of Gypsum Fibrosum and Gypsum Fibrosum Preparatum in promoting granulation. METHODS: The wounds of muscle layer were produced in rats by using surgical operation. Two round wounds, with diameter about 1.5 cm, were cut at the depilatory area of two sides of the back of each rat, with an interval of 2 cm, deep to muscle layer, and the thickness of the knife wound of muscle layer was about 0.15 cm. Forty SD rats with the wounds were randomly divided into 4 groups: untreated group, beifuji-treated group, Gypsum Fibrosum-treated group and Gypsum Fibrosum Preparatum-treated group, with 10 rats in each group. Then the wounds were sprinkled with powders of Gypsum Fibrosum and Gypsum Fibrosum Preparatum, or sprayed with beifuji solution, respectively. The healing state of granulation tissues of the wounds was observed at the eighth and fourteenth day respectively. RESULTS: The number of fibroblasts, the number of capillary tubes and the area of capillary tubes in granulation tissue of wounds in the Gypsum Fibrosum Preparatum-treated group were significantly higher than those in the untreated group and Gypsum Fibrosum-treated group (P<0.01). There were no statistical differences between the Gypsum Fibrosum Preparatum-treated group and the beifuji-treated group. However, Gypsum Fibrosum-treated group showed no obvious differences compared to the untreated group (P>0.05). CONCLUSIONS: Gypsum Fibrosum Preparatum can accelerate the formation of collagenoblast and micrangium in wounds, and the proliferation of granulation tissues, thus promoting the skin wounds to healing. The effect of Gypsum Fibrosum is changed after being calcined, and Gypsum Fibrosum Preparatum has obvious effect in promoting granulation.