Utility of Advanced DWI in the Detection of Spinal Cord Microstructural Alterations and Assessment of Neurologic Function in Cervical Spondylotic Myelopathy Patients.

BACKGROUND: Diffusion-weighted imaging (DWI) can quantify the microstructural changes in the spinal cord. It might be a substitute for T2 increased signal intensity (ISI) for cervical spondylotic myelopathy (CSM) evaluation and prognosis. PURPOSE: The purpose of the study is to investigate the relationship between DWI metrics and neurologic function of patients with CSM. STUDY TYPE: Retrospective. POPULATION: Forty-eight patients with CSM (18.8% females) and 36 healthy controls (HCs, 25.0% females). FIELD STRENGTH/SEQUENCE: 3 T; spin-echo echo-planar imaging-DWI; turbo spin-echo T1/T2; multi-echo gradient echo T2*. ASSESSMENT: For patients, conventional MRI indicators (presence and grades of T2 ISI), DWI indicators (neurite orientation dispersion and density imaging [NODDI]-derived isotropic volume fraction [ISOVF], intracellular volume fraction, and orientation dispersion index [ODI], diffusion tensor imaging [DTI]-derived fractional anisotropy [FA] and mean diffusivity [MD], and diffusion kurtosis imaging [DKI]-derived FA, MD, and mean kurtosis), clinical conditions, and modified Japanese Orthopaedic Association (mJOA) were recorded before the surgery. Neurologic function improvement was measured by the 3-month follow-up recovery rate (RR). For HCs, DWI, and mJOA were measured as baseline comparison. STATISTICAL TESTS: Continuous (categorical) variables were compared between patients and HCs using Student's t-tests or Mann-Whitney U tests (chi-square or Fisher exact tests). The relationships between DWI metrics/conventional MRI findings, and the pre-operative mJOA/RR were assessed using correlation and multivariate analysis. P < 0.05 was considered statistically significant. RESULTS: Among patients, grades of T2 ISI were not correlated with pre-surgical mJOA/RR (P = 0.717  and 0.175, respectively). NODDI ODI correlated with pre-operative mJOA (r = -0.31). DTI FA, DKI FA, and NODDI ISOVF were correlated with the recovery rate (r = 0.31, 0.41, and -0.34, respectively). In multivariate analysis, NODDI ODI (DTI FA, DKI FA, NODDI ISOVF) significantly contributed to the pre-operative mJOA (RR) after adjusting for age. DATA CONCLUSION: DTI FA, DKI FA, and NODDI ISOVF are predictors for prognosis in patients with CSM. NODDI ODI can be used to evaluate CSM severity. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.

Biventricular intraventricular mechanical and electrical dyssynchrony in pulmonary arterial hypertension.

Background: Pulmonary arterial hypertension (PAH) leads to myocardial remodeling, manifesting as mechanical dyssynchrony (M-dys) and electrical dyssynchrony (E-dys), in both right (RV) and left ventricles (LV). However, the impacts of layer-specific intraventricular M-dys on biventricular functions and its association with E-dys in PAH remain unclear. Methods: Seventy-nine newly diagnosed patients with PAH undergoing cardiac magnetic resonance scanning were consecutively recruited between January 2011 and December 2017. The biventricular volumetric and layer-specific intraventricular M-dys were analyzed. The QRS duration z-scores were calculated after adjusting for age and sex. Results: 77.22 % of patients were female (mean age 30.30 ± 9.79 years; median follow-up 5.53 years). Further, 29 (36.71 %) patients succumbed to all-cause mortality by the end of the study. At the baseline, LV layer-specific intraventricular M-dys had apparent transmural gradients compared with RV in the radial and circumferential directions. However, deceased patients lost the transmural gradients. The LV longitudinal strain rate time to late diastolic peak in the myocardial region (LVmyoLSRTTLDPintra) predicted long-term survival. The Kaplan-Meier curve revealed that patients with PAH with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. Larger right ventricle (RV) intraventricular M-dys resulted in worse RV ejection fraction. However, larger LV intraventricular M-dys in the late diastolic phase indicated remarkable exercise capacity and higher LV stroke volume index. E-dys and intraventricular M-dys had no direct correlations. Conclusions: The layer-specific intraventricular M-dys had varying impacts on biventricular functions in PAH. PAH patients with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. LV intraventricular M-dys in the late diastolic phase needs more attention to precisely evaluate LV function.

[Follow-up survey on the imported cases of lymphatic filariasis in Guangdong Province].

OBJECTIVE: To make a survey on the possible imported cases with microfilaremia from a recently identified outbreak focus in Fuchuan County of Guangxi Region. METHODS: Moving people as temporary laborers from Guangxi and periphery residents were screened by thick blood smears for microfilariae and ELISA for specific IgG4 in Sept 2007. RESULTS: 989 persons in cities/districts of Nansha, Panyu, Shantou and Zhongshan were investigated. Among 150 persons from Changtang administrative village of Guangxi, 47 were from two outbreak focuses, Ganshang and Yinshan natural villages in Changtang. Three cases with microfilaremia were found, with a microfilaraemia density of 24, 20 and 2 per 120 microl blood, respectively. The 3 cases were all from the 2 natural villages, with a microfilaraemia positive rate of 6.4% (3/47). Meanwhile, anti-filaria IgG4 was detected for other 1 501 persons, including those from the outbreak focuses, from surr-founding areas and from non-endemic area as control, fifteen cases were found with IgG4 positive. Of the 15 positive cases, 12 were from the 2 outbreak natural villages, with a positive rate of 25.5%, higher than those of others (chi2=295.83, P < 0.01). The cases with IgG4 positive but microfilaremia negative were reexamined by ICT kit and all showed negative. CONCLUSION: It is suggested that no further transmission occurs although microfilaremia cases have been imported from the outbreak focus of Guangxi.

[An investigation on nosocomial infection with severe acute respiratory syndrome in health-care workers at 13 key hospitals in Guangdong Province].

OBJECTIVE: To analysis the risk factors influencing nosocomial infection of severe acute respiratory syndrome (SARS) in health-care workers and to evaluate effectiveness of its control and preventive measures in 13 key hospitals caring for SARS patients. METHODS: Number of SARS patients, clinical conditions of them, its attack rate in health-care workers, and characteristics of hospitals, including their environment, isolating measures, etc. were investigated at the 13 hospital in Guangzhou to analyze the risk factors influencing nosocomial infection of SARS and its attack rates in health-care workers before and after implementation of preventive measures and to evaluate their effectiveness. RESULTS: Totally, 841 patients with SARS were treated at the 13 hospitals in Guangzhou and 285 health-care workers caring for them infected nosocomially. Attack rate in health-care workers was higher at general hospitals, hospital accepting more cases in critical conditions and hospitals with poor precautious measures, and lower in hospitals with isolated wards or areas, or department of infection, specially caring for SARS patients, and those with effective intervention measures to prevent secondary infection. CONCLUSION: Nosocomial infection of SARS in health-care workers was affected by clinical condition of SARS patients, characteristics and environment of hospitals and their personal protective measures adopted.

[Severe acute respiratory syndrome in Guangdong Province of China: epidemiology and control measures].

OBJECTIVE: To explore epidemiological features and risk factors of severe acute respiratory syndrome (SARS) in Guangdong Province of China, so as to work out effective strategies for its better control. METHODS: A total of 1 511 clinically confirmed SARS cases in Guangdong Province of China from November 16, 2002 to Jun 15, 2003 were retrospectively analyzed. RESULTS: The first SARS case was identified in Foshan municipality on November 16, 2002, followed by 1 511 clinically confirmed cases (including 58 deaths) up to May 15, 2003. Of all cases, health care workers and community family cluster cases accounted for 19.38% and 12.04%. 65.86% SARS patients aged 20 - 49 years, and increased incidence was positively related to their ages. 95.97% cases lived in the following five cities around Pearl Delta Area: Foshan, Guangzhou, Shenzhen, Zhongshan, and Jiangmen. Eleven early reported cases in the communities took animal-related positions. Face-to-face contacts with infected droplets were the main transmission route. An epidemic peak occurred during January 28 to February 26, and those cases accounted for 50.69% of total. Incidence, mortality, and case fatality of SARS were 1.77/100,000, 0.07/100,000, and 3.84% respectively. The mean incubation period was 4.5 days. CONCLUSION: The most effective way to control SARS is to break the chain of transmission from infected to healthy persons-early identification, prompt and effective isolation, and vigorous close contact tracing. Hospital infections among health care workers is critical. Several observations support the hypothesis of an animal origin for the disease.

[Endemic situation of schistosomiasis in Guangdong Province from 2004 to 2009].

OBJECTIVE: To understand the endemic situation of schistosomiasis in Guangdong Province. METHODS: The surveillance of Oncomelania hupensis snails and infectious sources was carried out in the former endemic areas, and the surveillance data were statistically analyzed from 2004 to 2009 according to the national and provincial surveillance protocols. RESULTS: From 2004 to 2009, an area of 927.45 hm2 was surveyed and no living snails were found, and 287 out of 12 345 young people living in the endemic areas showed serum positive with the DIGFA, but none of schistosomiasis patients were found. A total of 28 766 mobile population were involved in the DIGFA examination, and 417 persons were positive, among them, 52 chronic patients were found, and 6 patients had eggs in their stools. Through the passive surveillance, 281 cases were reported from 2003 to 2009, and 4 acute cases were reported from 2004 (1 case) to 2005 (3 cases). A total of 9 064 head of cattle were surveyed and none of them was infected with Schistosoma japonicum by stool examination. CONCLUSIONS: The achievements of schistosomiasis control are solidified in Guangdong Province. However, the risk of schistosomiasis transmission still remains. The surveillance should be continued, especially of imported infectious sources and snails.

[Effectiveness of personal protective measures in prevention of nosocomial transmission of severe acute respiratory syndrome].

OBJECTIVE: To evaluate the effectiveness of personal protective measures of health care workers (HCWs) against severe acute respiratory syndrome (SARS). METHODS: A case-control study from ten hospitals in Guangdong, with 180 non-infected and 77 infected staff members that accessed the isolation unit every day, and participated in direct first aid for severe SARS patients. All participants were surveyed about how they were using personal protective equipment (PPE), protective drugs and hygiene habits when caring for patients with SARS. Statistical analysis was done with either chi(2) or Fisher's exact test for univariate analysis, whereas we used forward stepwise selection (Waldesian) for logistic regression. RESULTS: Univariate analysis showed that mask, gown, gloves, goggles, footwear, "hand-washing and disinfecting", gargle, "membrane protection", "taking shower and changing clothing after work", "avoid from eating and drinking in ward", oseltamivir phospha tall had protective effects (P < 0.05), but stepwise logistic regression showed significant differences for mask (OR = 0.78, 95% CI: 0.60 - 0.99), goggles (OR = 0.20, 95% CI: 0.10 - 0.41) and footwear (OR = 0.58, 95% CI: 0.39 - 0.86). Analysis for linear trend in proportions showed that dose response relationship existed in mask, gown, gloves, goggles, footwear, gargle, "membrane protection" and "taking shower and changing dree after work" (P < 0.01). The attack rate of HCWs who were rescuing severe SARS patients without any PPE was 61.5% (16/26). It seemed that the more the protective measures were used, the higher the protective effect was (P < 0.001), and could reach 100% if mask, gown, gloves, goggles, footwear, "hand-washing and disinfecting" were all used at the same time. CONCLUSIONS: Nosocomial infection of SARS can be prevented effectively by precautions against droplets and personal contact. HCWs must take strict protection according to the guidance of WHO or Chinese MOH and pay attention to personal hygiene.