The influence of hospital accreditation on nurses' perceptions of patient safety culture.

OBJECTIVES: Hospitals' accreditation process is carried out to enhance the quality of hospitals' care and patient safety practices as well. The current study aimed to investigate the influence of hospitals' accreditation on patient safety culture as perceived by Jordanian hospitals among nurses. METHODS: A descriptive cross-sectional correlational survey was used for the current study, where the data were obtained from 395 nurses by convenient sampling technique who were working in 3 accredited hospitals with 254 nurses, and 3 non-accredited hospitals with 141 nurses, with a response rate of 89%. RESULTS: The overall patient safety culture was (71.9%). Moreover, the results of the current study revealed that there were no statistically significant differences between the perceptions of nurses in accredited and non-accredited hospitals in terms of perceptions of patient safety culture. CONCLUSION: The current study will add new knowledge about nurses' perceptions of patient safety culture in both accredited and non-accredited hospitals in Jordan which in turn will provide valid evidence to healthcare stakeholders if the accreditation status positively affects the nurses' perceptions of patient safety culture or not. Continuous evaluation of the accreditation application needs to be carried out to improve healthcare services as well as quality and patient safety.

Jordanian nursing students' knowledge and attitudes of corneal donation.

A high success rate of corneal transplants is evident. However, there is still a lack of corneal grafts available to meet demand, largely because donors are reluctant to donate. Given their critical role in future healthcare teaching and advocacy. There has not been much research on Jordanian nursing students' perspectives on corneal donation, so it's critical to identify and eliminate any obstacles. This study aims to evaluate the knowledge and attitudes of Jordanian nursing students concerning corneal donation. A cross-sectional, descriptive design was used to recruit (n = 440) nursing students from four Jordanian universities. A self-reported questionnaire was used to obtain data on knowledge and attitudes regarding corneal donation. The average age of senior nursing students was (M = 23.07, SD = 3.63) years. Varying levels of understanding were revealed amongst university students toward corneal donation items. Generally, good attitude of nursing students toward corneal donation (M = 34.1, SD = 8.1). Weak positive relationship was found between total knowledge scores and age (r = 0.141, p = 0.003) while there is no significant relationship between age and total attitude score (r = 0.031, p = 0.552). Age was found to be a significant predictor (B = 0.01, Beta = 0.12, t = 2.07, p = 0.04). Also, the educational level of fathers is a significant positive predictor (Beta = 0.128, p = 0.008) for the total attitude scores among nursing students. Limited awareness of corneal donation, highlighting the need for focused educational interventions to improve their comprehension.

A rare case of giant left circumflex coronary artery fistula to coronary sinus in patient with persistent left superior vena cava and bicuspid aortic valve.

A 61-year-old male presented with symptoms of decompensated heart failure and cardiogenic shock. Transthoracic and transesophageal echocardiography showed severely impaired left ventricular (LV) systolic function (LVEF of 20-25%), bicuspid aortic valve with moderate aortic insufficiency and no significant stenosis, dilated coronary sinus and a tortuous vascular structure in the left-sided atrioventricular groove. Cardiac computed tomography confirmed the diagnosis of persistent left superior vena cava and a giant coronary artery fistula to the coronary sinus. Cardiac magnetic resonance illustrated non-specific late gadolinium enhancement in the mid-wall of the septum. The patient was treated medically and with cardiac re-synchronization therapy.

Comparison of Liposomal Bupivacaine and Conventional Local Anesthetic Agents in Regional Anesthesia: A Systematic Review.

BACKGROUND: Pain is one of the most common adverse events after surgery. Regional anesthesia techniques are effective for pain control but have limited duration of action. Liposomal bupivacaine is a long-acting formulation of bupivacaine. We conduct this systematic review to assess whether liposomal bupivacaine may prolong the analgesic duration of regional anesthesia compared to conventional local anesthetic agents. METHODS: We systematically searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE (Ovid), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Google Scholar, Web of Science citation index, US clinical trials register, and recent conference abstracts for relevant studies. RESULTS: We identified 13 randomized controlled trials that compared the use of liposomal bupivacaine to conventional local anesthetics in regional anesthesia. There were 5 studies on transversus abdominis plane (TAP) block, 3 of which reported longer duration of analgesia with liposomal bupivacaine. One study reported comparable analgesia with liposomal bupivacaine TAP block compared to TAP block catheter. There were 3 studies on brachial plexus block, 2 of which reported that liposomal bupivacaine may provide longer analgesia. Studies on other techniques did not report significantly longer analgesia with liposomal bupivacaine. CONCLUSIONS: Currently, there is limited evidence suggesting that liposomal bupivacaine provides longer analgesia than conventional local anesthetics when used in regional anesthesia. The analyses of multiple studies on liposomal bupivacaine for TAP blocks and brachial plexus blocks have yielded conflicting results. As a result, no definitive conclusions can be drawn about its efficacy compared to plain bupivacaine.

Jordanian Nurses' Perceptions of Disaster Preparedness and Core Competencies.

OBJECTIVE: This study aims to identify the Jordanian nurses' perception of their disaster preparedness and core competencies. METHODS: A descriptive, cross-sectional research design was used. The data was collected via an online self-reported questionnaire using the disaster preparedness evaluation tool and the core disaster competencies tool. RESULTS: A total of 126 nurses participated in the study. Jordanian nurses had moderate to high levels of core disaster competencies and moderate levels of disaster preparedness. Core disaster competencies and disaster preparedness levels differed based on previous training on disaster preparedness, and the availability of an established emergency plan in their hospitals. Lastly, a previous training on disaster preparedness and core disaster competencies were statistically significant predictors of disaster preparedness among Jordanian nurses. CONCLUSIONS: Organizational factors and environmental contexts play a role in the development of such capabilities. Future research should focus on understanding the barriers and facilitators of developing core disaster competencies and disaster preparedness among nurses.

University Students' Physical Activity: Perceived Barriers and Benefits to Physical Activity and Its Contributing Factors.

Introduction: In general, undergraduate university students in the north of Jordan have a low level of physical activity. Objectives: To examine the physical activity level, perceived barriers and benefits to physical activity, and the contributing factors among university students in north of Jordan. Methods: A cross-sectional study design was used, and data was collected from 235 university students through a self-reported questionnaire. The International Physical Activity Questionnaire (IPAQ) was utilized to calculate the amount of physical activity, while the exercise benefits and barriers scale (EBBS) was used to measure the perceived benefits and barriers of physical activity. Results: According to the findings, less than half of the students (48.1%) reported engaging in physical activity. Several factors were found to be significantly related to higher levels of physical activity, including being younger, single, having a normal body weight, and reporting excellent health status. Logistic regression analysis revealed that overweight (OR = -0.068, 95% CI 0.025-0.183) and obese (OR = -0.250, 95% CI 0.068-0.924) were less likely to be physically active, while those who rated their health as excellent had higher rates of physical activity (OR = 3.590, 95% CI 1.263-10.201). The students agreed most strongly with the perceived benefit item "Exercise improves the way my body looks," while the perceived barrier item they identified most strongly with was "There are too few places for me to exercise." Conclusion: This study provides important data for health promotion programs aimed at supporting physical activity among university students.

PET/MRI Assessment of Acute Cardiac Inflammation 1 Month After Left-Sided Breast Cancer Radiation Therapy.

Our purpose was to investigate the utility of 18F-FDG PET/MRI and serial blood work to detect early inflammatory responses and cardiac functionality changes at 1 mo after radiation therapy (RT) in patients with left-sided breast cancer. Methods: Fifteen left-sided breast cancer patients who enrolled in the RICT-BREAST study underwent cardiac PET/MRI at baseline and 1 mo after standard RT. Eleven patients received deep-inspiration breath-hold RT, whereas the others received free-breathing RT. A list-mode 18F-FDG PET scan with glucose suppression was acquired. Myocardial inflammation was quantified by the change in 18F-FDG SUVmean (based on body weight) and analyzed on the basis of the myocardial tissue associated with the left anterior descending, left circumflex, or right coronary artery territories. MRI assessments, including left ventricular functional and extracellular volumes (ECVs), were extracted from T1 (before and during a constant infusion of gadolinium) and cine images, respectively, acquired simultaneously during the PET acquisition. Cardiac injury and inflammation biomarker measurements of high-sensitivity troponin T, high-sensitivity C-reactive protein, and erythrocyte sedimentation rate were measured at the 1-mo follow-up and compared with preirradiation values. Results: At the 1-mo follow-up, a significant increase (10%) in myocardial SUVmean in left anterior descending segments (P = 0.04) and ECVs in slices at the apex (6%) and base (5%) was detected (P ≤ 0.02). Further, a significant reduction in left ventricular stroke volume (-7%) was seen (P < 0.02). No significant changes in any circulating biomarkers were seen at follow-up. Conclusion: Myocardial 18F-FDG uptake and functional MRI, including stroke volume and ECVs, were sensitive to changes at 1 mo after breast cancer RT, with findings suggesting an acute cardiac inflammatory response to RT.

Perceived Relationship Between Horizontal Violence and Patient Safety Culture Among Nurses.

Objective: Despite the value of undertaking patient safety culture, its association with horizontal violence in nursing workplace is still understudied. This study aimed to investigate the association between the perceived patient safety culture and its relationship with horizontal violence among nurses working in Jordan. Methods: A cross-sectional correlational design was used. Nurses working in major governmental hospitals in Jordan were conveniently recruited to complete an online self-administered questionnaire, which included the following tools: Hospital Survey on Patient Safety Culture and Negative Behaviours in Healthcare (NBHC) Survey. The survey was designed to measure attitudes and perceptions on patient safety culture at multiple levels of a healthcare organization with ten dimensions. The Negative Behaviours in Healthcare (NBHC) survey was developed as an adaptation of the Lateral Violence in Nursing Survey (LVNS) with 25 items and two open-ended questions. Results: A total of 330 nurses responded to the questionnaire. Nurses moderately perceived patient safety culture (HSOPS mean = 3.5, SD = 1.1). Low incidence of horizontal violence was claimed (mean = 2.1, SD = 1.1). However, it was associated with moderate negative correlation with patient safety culture (r = -0.53, p < 0.001). Regression model revealed that patient safety culture explained an additional 53% of the variance of horizontal violence after controlling the effects of age and length of clinical experience (R-square change: 0.560, SE: 19.7, P: 0.001, CI: 1.21-1.57). Conclusion: Despite its low incidence, patient safety culture was found influential to the horizontal violence based on the perspectives of nurses in Jordan. Patient safety culture can be incorporated with other factors that contribute to the development of horizontal violence in nursing workplace.

Nurses' perceptions of the influence of leadership behaviours and organisational culture on patient safety incident reporting practices.

BACKGROUND: Patient safety is a priority for all healthcare organisations. Enhancing patient safety incident reporting practices requires effective leadership behaviours at all levels in healthcare organisations. AIM: To explore nurses' perceptions of the influence of nurse managers' leadership behaviours and organisational culture on patient safety incident reporting practices. METHOD: A descriptive, cross-sectional, correlational design was adopted with a convenience sample of 325 nurses from 15 Jordanian hospitals. RESULTS: Respondents had positive perceptions of their nurse managers' leadership behaviours and organisational culture. There was a significant positive relationship between leadership behaviours and organisational culture (r=0.423, P<0.001) and between leadership behaviours and actual incident-reporting practices (r=0.131, P<0.001). Additionally, there was a significant positive relationship between organisational culture and incident-reporting practices (r=0.250, P<0.001). CONCLUSION: Healthcare organisations must develop leaders who will foster a supportive and just culture that will enhance nurses' practice with regards to reporting patient safety incidents.

Non-invasive assessment of functionally relevant coronary artery stenoses with quantitative CT perfusion: preliminary clinical experiences.

OBJECTIVES: We developed a quantitative Dynamic Contrast-Enhanced CT (DCE-CT) technique for measuring Myocardial Perfusion Reserve (MPR) and Volume Reserve (MVR) and studied their relationship with coronary stenosis. METHODS: Twenty-six patients with Coronary Artery Disease (CAD) were recruited. Degree of stenosis in each coronary artery was classified from catheter-based angiograms as Non-Stenosed (NS, angiographically normal or mildly irregular), Moderately Stenosed (MS, 50-80% reduction in luminal diameter), Severely Stenosed (SS, >80%) and SS with Collaterals (SSC). DCE-CT at rest and after dipyridamole infusion was performed using 64-slice CT. Mid-diastolic heart images were corrected for beam hardening and analyzed using proprietary software to calculate Myocardial Blood Flow (MBF, in mL∙min(-1)∙100 g(-1)) and Blood Volume (MBV, in mL∙100 g(-1)) parametric maps. MPR and MVR in each coronary territory were calculated by dividing MBF and MBV after pharmacological stress by their respective baseline values. RESULTS: MPR and MVR in MS and SS territories were significantly lower than those of NS territories (p < 0.05 for all). Logistic regression analysis identified MPR∙MVR as the best predictor of ≥50% coronary lesion than MPR or MVR alone. CONCLUSIONS: DCE-CT imaging with quantitative CT perfusion analysis could be useful for detecting coronary stenoses that are functionally significant.

Hyperpolarized 129Xe Pulmonary MRI and Asymptomatic Atrial Septal Defect.

In an asymptomatic 19-year-old who regularly underwent cardiopulmonary fitness testing for national lifeguard-accreditation, 129Xe MRI unexpectedly revealed an abnormally augmented RBC signal and RBC-to-alveolar-capillary-tissue ratio with spatially homogeneous ventilation, tissue barrier, and RBC images. Pulmonary function was normal, but cardiopulmonary follow-up including transthoracic and transesophageal echocardiogram, heart catheterization, and contrast-enhanced cardiac CT imaging led to the diagnosis of a large (20 × 27 mm) secundum atrial septal defect (ASD) with a net right-to-left shunt (Qp:Qs = 0.5) and normal pulmonary pressures. This novel, unexpected case revealed that 129Xe RBC signal intensity likely reflected erythrocytosis, compensatory to the abnormal cardiovascular hemodynamics that resulted from a large congenital ASD. Unlike ASD cases that present with dyspnea and exercise limitation, this 129Xe MRI abnormality was detected in an asymptomatic teenager. This is the first report of asymptomatic adult congenital heart disease diagnosed subsequent to novel 129Xe MRI that led to early intervention, avoiding long-term complications of cyanosis, including ventricular fibrosis and thromboembolic and bleeding risks.

3D Motion Estimation of Left Ventricular Dynamics Using MRI and Track-to-Track Fusion.

OBJECTIVE: This study investigates the estimation of three dimensional (3D) left ventricular (LV) motion using the fusion of different two dimensional (2D) cine magnetic resonance (CMR) sequences acquired during routine imaging sessions. Although standard clinical cine CMR data is inherently 2D, the actual underlying LV dynamics lies in 3D space and cannot be captured entirely using single 2D CMR image sequences. By utilizing the image information from various short-axis and long-axis image sequences, the proposed method intends to estimate the dynamic state vectors consisting of the position and velocity information of the myocardial borders in 3D space. METHOD: The proposed method comprises two main components: tracking myocardial points in 2D CMR sequences and fusion of multiple trajectories correspond to the tracked points. The tracking which yields the set of corresponding temporal points representing the myocardial points is performed using a diffeomorphic nonrigid image registration approach. The trajectories obtained from each cine CMR sequence is then fused with the corresponding trajectories from other CMR views using an unscented Kalman smoother (UKS) and a track-to-track fusion algorithm. RESULTS: We evaluated the proposed method by comparing the results against CMR imaging with myocardial tagging. We report a quantitative performance analysis by projecting the state vector estimates we obtained onto 2D tagged CMR images acquired from the same subjects and comparing them against harmonic phase estimates. The proposed algorithm yielded a competitive performance with a mean root mean square error of 1.3±0.5 pixels (1.8±0.6 mm) evaluated over 118 image sequences acquired from 30 subjects. CONCLUSION: This study demonstrates that fusing the information from short and long-axis views of CMR improves the accuracy of cardiac tissue motion estimation. Clinical Impact: The proposed method demonstrates that the fusion of tissue tracking information from long and short-axis views improves the binary classification of the automated regional function assessment.

Egyptian Propolis-Loaded Nanoparticles as a Root Canal Nanosealer: Sealing Ability and in vivo Biocompatibility.

BACKGROUND: Successful endodontic therapy is mainly governed by the satisfactory sealing ability of the applied root canal sealer. Also, tolerability of root canal structure to accommodate the presence of a sealer participates in the efficiency of the treatment. Hence, this study was aimed to extrapolate our previous one that was concerned with the preparation and evaluation of novel nature-based root canal sealers. Our current work is focused on the evaluation of sealing ability and in vivo biocompatibility. MATERIALS AND METHODS: Egyptian propolis was extracted (ProE) and encapsulated in polymeric nanoparticles (ProE-loaded NPs). Two root sealers, PE sealer and PE nanosealer, were fabricated by incorporating ProE and ProE-loaded NPs, respectively. The sealing ability of the developed sealers was tested by a dye extraction method. An in vivo biocompatibility study was conducted using a subcutaneous implantation method for two and four weeks. At the same time, a model sealer (AH Plus®) was subjected to the same procedures to enable accurate and equitable results. RESULTS: The teeth treated with PE sealer exhibited weak sealing ability which did not differ from that of unfilled teeth. PE nanosealer enhanced the sealing ability similarly to the model sealer with minimal apical microleakage. Studying in vivo biocompatibility indicated the capability of the three tested sealers to induce cell proliferation and tissue healing. However, PE nanosealer had superior biocompatibility, with higher potential for cell regeneration and tissue proliferation. CONCLUSION: PE nanosealer can be presented as an innovative root canal sealer, with enhanced sealing ability as well as in vivo biocompatibility. It can be applied as a substitute for the currently available sealers that demonstrate hazardous effects.

Cubic-Spline Interpolation for Sparse-View CT Image Reconstruction With Filtered Backprojection in Dynamic Myocardial Perfusion Imaging.

We investigated a projection interpolation method for reconstructing dynamic contrast-enhanced (DCE) heart images from undersampled x-ray projections with filtered backprojecton (FBP). This method may facilitate the application of sparse-view dynamic acquisition for ultralow-dose quantitative computed tomography (CT) myocardial perfusion (MP) imaging. We conducted CT perfusion studies on 5 pigs with a standard full-view acquisition protocol (984 projections). We reconstructed DCE heart images with FBP from all and a quarter of the measured projections evenly distributed over 360°. We interpolated the sparse-view (quarter) projections to a full-view setting using a cubic-spline interpolation method before applying FBP to reconstruct the DCE heart images (synthesized full-view). To generate MP maps, we used 3 sets of DCE heart images, and compared mean MP values and biases among the 3 protocols. Compared with synthesized full-view DCE images, sparse-view DCE images were more affected by streak artifacts arising from projection undersampling. Relative to the full-view protocol, mean bias in MP measurement associated with the sparse-view protocol was 10.0 mL/min/100 g (95%CI: -8.9 to 28.9), which was >3 times higher than that associated with the synthesized full-view protocol (3.3 mL/min/100 g, 95% CI: -6.7 to 13.2). The cubic-spline-view interpolation method improved MP measurement from DCE heart images reconstructed from only a quarter of the full projection set. This method can be used with the industry-standard FBP algorithm to reconstruct DCE images of the heart, and it can reduce the radiation dose of a whole-heart quantitative CT MP study to <2 mSv (at 8-cm coverage).

Design, Evaluation And Antimicrobial Activity Of Egyptian Propolis-Loaded Nanoparticles: Intrinsic Role As A Novel And Naturally Based Root Canal Nanosealer.

BACKGROUND: Propolis is a unique natural adhesive product collected by honeybees. It contains a diversity of bioactive compounds with reported functional properties such as antioxidants, antibacterial, antifungal, anti-inflammatory, antiviral and anticancer activity. Dental caries is a worldwide problem that caused by microbial growth usually progress from tooth enamel to the underlying pulpal tissues and root canal. This situation could be controlled by a sequence of steps to remove microorganisms and fill root canal with a suitable long-lasting root canal sealer. Unfortunately, leachable and degradation products of the currently used sealers compromised their antimicrobial activity by inflammatory modulation associated with irritation and toxicity of periapical tissues. MATERIALS AND METHODS: Hence, propolis was selected to be designed as a natural root canal sealer due to its amazing functional properties. Moreover, its handling properties were enhanced and potentiated by its incorporation in polymeric nanoparticles (NPs). Frist, propolis was collected, extracted and analyzed for its bioactive compounds. After that, propolis-loaded NPs of PLGA (ProE-loaded NPs) were developed and fully characterized regarding physicochemical properties, in vitro release and in vitro cytotoxicity. Then, root canal sealers were fabricated and assayed for their antimicrobial activity. Both cytotoxicity and antimicrobial activity were compared to those of a model sealer; AH Plus®. RESULTS: The results revealed that spherical nanoscopic NPs with narrow size distribution were obtained. ProE-loaded NPs exhibited accepted entrapment efficiency (>80) and prolonged release. In vitro cytotoxicity study confirmed the safety of ProE-loaded NPs. Also, the developed sealers showed antimicrobial activity versus bacterial strains of Enterococcus faecalis and Streptococcus mutans and antifungal activity against Candida albicans. CONCLUSION: ProE-loaded NPs could be incorporated in and represented as a root canal sealer with prolonged release and enhanced cytocompatibility as well as antimicrobial activities.

Molecular Dynamics Simulation of Amorphous SiO2, B2O3, Na2O-SiO2, Na2O-B2O3, and Na2O-B2O3-SiO2 Glasses with Variable Compositions and with Cs2O and SrO Dopants.

Selection of suitable glass composition for vitrification of high-level radioactive wastes (HLWs) is one of the major challenges in nuclear waste reprocessing. Atomic and molecular level understanding of various structural, thermodynamical, and dynamical properties of a glass matrix can help in preliminary screening and thus reduce the dependency to some extent on tedious experimental procedures. In that context, extensive molecular dynamics (MD) simulations have been performed to calculate various microscopic properties of the glass matrix. The present article demonstrates that the "Buckingham potential-included long-ranged Coulomb interaction" can be utilized to simulate the glasses of varied compositions. The proposed simulation model has been validated for a wide range of glass compositions: pure glass matrix-SiO2 and B2O3; binary glass mixtures-SiO2-B2O3, Na2O-SiO2, and Na2O-B2O3; ternary glass-Na2O-SiO2-B2O3; and also the Cs2O- and SrO-doped matrix of sodium borosilicate. Most importantly, the MD results have been validated with those of in-house synthesized glasses. The effect of alkali addition on the density and network connectivity of the glass matrix has been explored. The results capture well the boron anomalies for varied concentrations of network formers and network modifiers. The intermediate structural ordering in glasses has been explored by calculating the partial and total structure factors. Further, the characteristic vibration density of states of constituent atoms in the glass matrix is determined. In addition, the glass structures with the addition of dopant oxides Cs2O and SrO have been examined as they are known to be prime heat-generating agents in HLWs. The results establish the structure and dynamics of the doped glass matrix to be a complex nature of the dopant's mass, concentration, charge, and ionic radius. The present MD results might be of great academic and technological significance for further studies in the field of vitrification and prediction of effects associated with the dopant's nature and concentration.

Ultra-low dose quantitative CT myocardial perfusion imaging with sparse-view dynamic acquisition and image reconstruction: A feasibility study.

PURPOSE: We implemented and validated a compressed sensing (CS) based algorithm for reconstructing dynamic contrast-enhanced (DCE) CT images of the heart from sparsely sampled X-ray projections. METHODS: DCE CT imaging of the heart was performed on five normal and ischemic pigs after contrast injection. DCE images were reconstructed with filtered backprojection (FBP) and CS from all projections (984-view) and 1/3 of all projections (328-view), and with CS from 1/4 of all projections (246-view). Myocardial perfusion (MP) measurements with each protocol were compared to those with the reference 984-view FBP protocol. RESULTS: Both the 984-view CS and 328-view CS protocols were in good agreements with the reference protocol. The Pearson correlation coefficients of 984-view CS and 328-view CS determined from linear regression analyses were 0.98 and 0.99 respectively. The corresponding mean biases of MP measurement determined from Bland-Altman analyses were 2.7 and 1.2ml/min/100g. When only 328 projections were used for image reconstruction, CS was more accurate than FBP for MP measurement with respect to 984-view FBP. However, CS failed to generate MP maps comparable to those with 984-view FBP when only 246 projections were used for image reconstruction. CONCLUSION: DCE heart images reconstructed from one-third of a full projection set with CS were minimally affected by aliasing artifacts, leading to accurate MP measurements with the effective dose reduced to just 33% of conventional full-view FBP method. The proposed CS sparse-view image reconstruction method could facilitate the implementation of sparse-view dynamic acquisition for ultra-low dose CT MP imaging.

Functional CT assessment of extravascular contrast distribution volume and myocardial perfusion in acute myocardial infarction.

PURPOSE: In a pig model of acute myocardial infarction (AMI), we validated a functional computed tomography (CT) technique for concomitant assessment of myocardial edema and ischemia through extravscualar contrast distribution volume (ECDV) and myocardial perfusion (MP) measurements from a single dynamic imaging session using a single contrast bolus injection. METHODS: In seven pigs, balloon catheter was used to occlude the distal left anterior descending artery for one hour followed by reperfusion. CT and cardiac magnetic resonance (CMR) imaging studies were acquired on 3 days and 12 ±â€¯3 day post ischemic insult. In each CT study, 0.7 ml/kg of iodinated contrast was intravenously injected at 3-4 ml/s before dynamic contrast-enhanced (DCE) cardiac images were acquired with breath-hold using a 64-row CT scanner. DCE cardiac images were analyzed with a model-based deconvolution to generate ECDV and MP maps. ECDV as an imaging marker of edema was validated against CMR T2 weighted imaging in normal and infarcted myocardium delineated from ex-vivo histological staining. RESULTS: ECDV in infarcted myocardium was significantly higher (p < 0.05) than that in normal myocardium on both days post AMI and was in agreement with the findings of CMR T2 weighted imaging. MP was significantly lower (p < 0.05) in the infarcted region compared to normal on both days post AMI. CONCLUSION: This imaging technique can rapidly and simultaneously assess myocardial edema and ischemia through ECDV and MP measurements, and may be useful for delineation of salvageable tissue within at-risk myocardium to guide reperfusion therapy.

Direct Multitype Cardiac Indices Estimation via Joint Representation and Regression Learning.

Cardiac indices estimation is of great importance during identification and diagnosis of cardiac disease in clinical routine. However, estimation of multitype cardiac indices with consistently reliable and high accuracy is still a great challenge due to the high variability of cardiac structures and the complexity of temporal dynamics in cardiac MR sequences. While efforts have been devoted into cardiac volumes estimation through feature engineering followed by a independent regression model, these methods suffer from the vulnerable feature representation and incompatible regression model. In this paper, we propose a semi-automated method for multitype cardiac indices estimation. After the manual labeling of two landmarks for ROI cropping, an integrated deep neural network Indices-Net is designed to jointly learn the representation and regression models. It comprises two tightly-coupled networks, such as a deep convolution autoencoder for cardiac image representation, and a multiple output convolution neural network for indices regression. Joint learning of the two networks effectively enhances the expressiveness of image representation with respect to cardiac indices, and the compatibility between image representation and indices regression, thus leading to accurate and reliable estimations for all the cardiac indices. When applied with five-fold cross validation on MR images of 145 subjects, Indices-Net achieves consistently low estimation error for LV wall thicknesses (1.44 ± 0.71 mm) and areas of cavity and myocardium (204 ± 133 mm2). It outperforms, with significant error reductions, segmentation method (55.1% and 17.4%), and two-phase direct volume-only methods (12.7% and 14.6%) for wall thicknesses and areas, respectively. These advantages endow the proposed method a great potential in clinical cardiac function assessment.

Descriptor Learning via Supervised Manifold Regularization for Multioutput Regression.

Multioutput regression has recently shown great ability to solve challenging problems in both computer vision and medical image analysis. However, due to the huge image variability and ambiguity, it is fundamentally challenging to handle the highly complex input-target relationship of multioutput regression, especially with indiscriminate high-dimensional representations. In this paper, we propose a novel supervised descriptor learning (SDL) algorithm for multioutput regression, which can establish discriminative and compact feature representations to improve the multivariate estimation performance. The SDL is formulated as generalized low-rank approximations of matrices with a supervised manifold regularization. The SDL is able to simultaneously extract discriminative features closely related to multivariate targets and remove irrelevant and redundant information by transforming raw features into a new low-dimensional space aligned to targets. The achieved discriminative while compact descriptor largely reduces the variability and ambiguity for multioutput regression, which enables more accurate and efficient multivariate estimation. We conduct extensive evaluation of the proposed SDL on both synthetic data and real-world multioutput regression tasks for both computer vision and medical image analysis. Experimental results have shown that the proposed SDL can achieve high multivariate estimation accuracy on all tasks and largely outperforms the algorithms in the state of the arts. Our method establishes a novel SDL framework for multioutput regression, which can be widely used to boost the performance in different applications.