Dynamic Myocardial Ultrasound Localization Angiography.

Dynamic Myocardial Ultrasound Localization Angiography (MULA) is an ultrasound-based imaging modality destined to enhance the diagnosis and treatment monitoring of coronary pathologies. Current diagnosis methods of coronary artery disease focus on the observation of vessel narrowing in the coronary vasculature to assess the organ's condition. However, we would strongly benefit from mapping and measuring flow from intramyocardial arterioles and capillaries as they are the direct vehicle of the myocardium blood income. With the advent of ultrafast ultrasound scanners, imaging modalities based on the localization and tracking of injected microbubbles allow for the subwavelength resolution imaging of an organ's vasculature. Yet, the application of these vascular imaging modalities relies on an accumulation of cine loops of a region of interest undergoing no or minimal tissue motion. This work introduces the MULA framework that combines 1) the mapping of the dynamics of the microvascular flow using an ultrasound sequence triggered by the electrocardiogram with a 2) novel Lagrangian beamformer based on non-rigid motion registration algorithm to form images directly in the myocardium's material coordinates and thus correcting for the large myocardial motion and deformation. Specifically, we show that this framework enables the non-invasive imaging of the angioarchitecture and dynamics of intramyocardial flow in vessels as small as a few tens of microns in the rat's beating heart in vivo.

[Influenza incidence estimated with a rapid diagnostic test in critically ill patients with acute respiratory failure during the 2005 and 2006 winter flu epidemics]. / Incidence de la grippe estimée par un test de diagnostic rapide chez les patients hospitalisés en réanimation pour détresse respiratoire aiguë en période d'épidémie grippale durant les hivers 2005 et 2006.

OBJECTIVE: To estimate the incidence of influenza infection with a rapid diagnostic test in patients hospitalized in an intensive care unit (ICU) during the epidemic periods of two consecutive winters (2005-2006). METHODS: This study tested nasal aspirate of all patients admitted to the ICU for acute respiratory failure during the influenza epidemic period with the QuickVue influenza rapid diagnostic test. RESULTS: The study included 39 patients: 22 men and 17 women. Their mean age was 69.7+/-13 years, their mean SAPS II score 54+/-21, their mean length of stay 14.7+/-20 days, and 43.5% had been vaccinated against influenza. The mortality rate was 33.3% (n=13). Four patients (10.2%) had a positive QuickVue test and were considered to have influenza associated with their primary diagnosis: pneumococcal pneumonia, haemophilus pneumonia, acute bronchitis, and acute bronchitis with acute cardiogenic edema. These patients were older than those with a negative test (80+/-7 versus 68+/-13 years, p=0.02). Their SAPS II, length of stay and mortality rate did not differ statistically from those with negative results. Chronic heart failure (but not COPD or non-vaccination) was more frequent in these patients (p=0.01). DISCUSSION: Several published studies report a satisfactory specificity and sensitivity for QuickVue. With this test, we estimated the incidence of influenza in patients hospitalized in our ICU for acute respiratory failure during flu epidemics at around 10%, close to that reported in previous studies.