Intravoxel Incoherent Motion and Dynamic Contrast-Enhanced Magnetic Resonance Imaging to Early Detect Tissue Injury and Microcirculation Alteration in Hepatic Injury Induced by Intestinal Ischemia-Reperfusion in a Rat Model.

BACKGROUND: Intravoxel incoherent motion (IVIM) can provide quantitative information about water diffusion and perfusion that can be used to evaluate hepatic injury, but it has not been studied in hepatic injury induced by intestinal ischemia-reperfusion (IIR). Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) can provide perfusion data, but it is unclear whether it can provide useful information for assessing hepatic injury induced by IIR. PURPOSE: To examine whether IVIM and DCE-MRI can detect early IIR-induced hepatic changes, and to evaluate the relationship between IVIM and DCE-derived parameters and biochemical indicators and histological scores. STUDY TYPE: Prospective pre-clinical study. POPULATION: Forty-two male Sprague-Dawley rats. FIELD STRENGTH/SEQUENCE: IVIM-diffusion-weighted imaging (DWI) using diffusion-weighted echo-planar imaging sequence and DCE-MRI using fast spoiled gradient recalled-based sequence at 3.0 T. ASSESSMENT: All rats were randomly divided into the control group (Sham), the simple ischemia group, the ischemia-reperfusion (IR) group (IR1h, IR2h, IR3h, and IR4h) in a model of secondary hepatic injury caused by IIR, and IIR was induced by clamping the superior mesenteric artery for 60 minutes and then removing the vascular clamp. Advanced Workstation (AW) 4.6 was used to calculate the imaging parameters (apparent diffusion coefficient [ADC], true diffusion coefficient [D], perfusion-related diffusion [D* ] and volume fraction [f]) of IVIM. OmniKinetics (OK) software was used to calculate the DCE imaging parameters (Ktrans , Kep , and Ve ). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed with an automatic biochemical analyzer. Superoxide dismutase (SOD) activity was assessed using the nitro-blue tetrazolium method. Malondialdehyde (MDA) was determined by thiobarbituric acid colorimetry. Histopathology was performed with hematoxylin and eosin staining. STATISTICAL TESTS: One-way analysis of variance (ANOVA) and Bonferroni post-hoc tests were used to analyze the imaging parameters and biochemical indicators among the different groups. Pearson correlation analysis was applied to determine the correlation between imaging parameters and biochemical indicators or histological score. RESULTS: ALT and MDA reached peak levels at IR4h, while SOD reached the minimum level at IR4h (all P < 0.05). ADC, D, D* , and f gradually decreased as reperfusion continued, and Ktrans and Ve gradually increased (all P < 0.05). The degrees of change for f and Ve were greater than those of other imaging parameters at IR1h (all P < 0.05). All groups showed good correlation between imaging parameters and SOD and MDA (r[ADC] = 0.615, -0.666, r[D] = 0.493, -0.612, r[D* ] = 0.607, -0.647, r[f] = 0.637, -0.682, r[Ktrans ] = -0.522, 0.500, r[Ve ] = -0.590, 0.665, respectively; all P < 0.05). However, the IR groups showed poor or no correlation between the imaging parameters and SOD and MDA (P [Ktrans and MDA] = 0.050, P [D and SOD] = 0.125, P [the remaining imaging parameters] < 0.05). All groups showed a positive correlation between histological score and Ktrans and Ve (r = 0.775, 0.874, all P < 0.05), and a negative correlation between histological score and ADC, D, f, and D* (r = -0.739, -0.821, -0.868, -0.841, respectively; all P < 0.05). For the IR groups, there was a positive correlation between histological score and Ktrans and Ve (r = 0.747, 0.802, all P < 0.05), and a negative correlation between histological score and ADC, D, f, and D* (r = -0.567, -0.712, -0.715, -0.779, respectively; all P < 0.05). DATA CONCLUSION: The combined application of IVIM and DCE-MRI has the potential to be used as an imaging tool for monitoring IIR-induced hepatic histopathology. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

Nurses' knowledge, attitudes, and behaviors toward venous thromboembolism prophylaxis: How to do better.

OBJECTIVES: To investigate the cognition of nurses on the control and treatment of venous thromboembolism in China, thereby providing suitable countermeasures for clinical venous thromboembolism prophylaxis and treatment. METHODS: In December 2019, a total of 1121 registered nurses from a university-affiliated hospital were selected to answer the self-designed and electronic questionnaire (Wenquanxing: www.wjx.cn/), which was designed to evaluate the nurses' knowledge (21 items), attitudes (6 items), and behaviors (9 items) toward venous thromboembolism prophylaxis. Descriptive, correlation, and regression analyses were conducted for data analysis. RESULTS: Of the included 1121 nurses, only 55.43% nurses selected 100% correct answer. The influencing factors of knowledge included the department, education, professional ranks, and venous thromboembolism nursing experience. The nurses from ICU department gained the highest score, but the nurses from pediatrics department obtained the lowest score. The nurses with higher education level and professional ranks, and nursing experiences achieved higher scores. The total positive response rate for the attitude-related items was 68.54%. Nurses were primarily concerned about the financial penalty due to the inability to complete the work (49.0%). An increasing workload is the second primary concern of nurses (40.8%). The increasing medical cost, extension of hospital stay, and exacerbation of doctor-patient conflicts were the most serious difficulties involved in venous thromboembolism prophylaxis. The total correct score rate for the behaviors was 56.19%. Nearly half of the nurses could not offer advice for venous thromboembolism patients. The nursing experience, department, and years of work were related to the scores of knowledge-related items (all P < 0.05). CONCLUSIONS: The overall knowledge level of the nurses was not optimistic. Although their general attitude toward venous thromboembolism prophylaxis was positive, their behaviors were influenced by many factors. Administrators should, therefore, make countermeasures to deal with these problems.

Knowledge, Behaviors, and Attitudes Regarding Venous Thromboembolism Prophylaxis: A Survey of Clinicians at a Tertiary Hospital of China.

BACKGROUND: In this study, we sought to assess knowledge, attitudes, and behaviors regarding venous thromboembolism (VTE) prophylaxis among clinicians at a tertiary hospital of China. METHODS: An electronic questionnaire was sent to clinicians to gather information regarding demographic data (5 items), knowledge about VTE prophylaxis (21 items), behaviors regarding VTE prophylaxis (8 items), and attitudes regarding VTE prophylaxis (7 items). Answers of "strongly agree" and "agree" on the behaviors and attitude items were defined as affirmative responses. Clinicians were also asked to provide suggestions regarding VTE prophylaxis. RESULTS: A total of 867 clinicians were included in this study. The overall correct response rate for knowledge items was 60.9%. The median affirmative response rate for behavior items was 48.6% (range 29.5-80.3%), and the median affirmative response rate for attitude items was 98.7% (range 96.9-99.3%). Clinicians were most concerned about the adverse effects triggered by chemical VTE prophylaxis (79.5%) and possibility of a financial penalty when a patient could not be treated with VTE prophylaxis (72.3%). Low patient compliance and low level of clinician knowledge and participation were identified most commonly as difficulties involved in VTE prophylaxis. A total of 78 suggestions were collected; these suggestions generally focused on improving the quality and frequency of staff training (n = 24) and enhancing learning opportunities (n = 22). CONCLUSIONS: Although the clinicians' overall attitude toward VTE prophylaxis was positive, the knowledge level was relatively poor, and the rate of affirmative responses regarding behaviors was low. Medical institutions should improve clinician training regarding VTE prophylaxis.

Comparison of CTA and DSA in the diagnosis of superior mesenteric artery dissecting aneurysm.

Objective To compare computed tomography arteriography (CTA) and digital subtraction arteriography (DSA) in the diagnosis of superior mesenteric artery dissecting aneurysm (SMADA). Methods All SMADA patients who underwent CTA and DSA at one of two medical centers between May, 2007 and April, 2017 were identified. The accuracy of CTA and DSA for the depiction of morphologic characteristics of SMADA was analyzed. Results Fourteen patients (12 men; mean age, 55.1 ± 6.4 years) were included in this study. The mean diameter of the dissecting aneurysm was 3.78 ± 1.53 mm on CTA and 3.81 ± 1.54 mm on DSA ( p = 0.96). The luminal stenosis was 0.52 ± 0.27 on CTA and 0.35 ± 0.23 on DSA ( p = 0.09). The thrombosed false lumen was visualized on CTA in 79% (11/14) of patients but in no patients on DSA ( p < 0.001). The entry points of the dissection were visualized on CTA in 64.3% (9/14) of patients and on DSA in 100% (14/14) of patients ( p = 0.041); CTA and DSA did not visualize re-entry points in any patients. The intimal flap was visualized on CTA in 71.4% (10/14) of patients and on DSA in 78.6% (11/14) of patients ( p > 0.05). Branch vessel involvement was visualized in 7.1% (1/14) of patients on CTA but in no patients on DSA ( p > 0.05). Conclusions CTA can be used in place of DSA for the diagnosis of SMADA. Although CTA may exaggerate the degree of luminal stenosis and is weak in depicting the entry points of SMADA, this modality more accurately depicts the thrombosed false lumen and branch vessel involvement.