Vehicle Firearm Storage: Prevalence and Correlates in a Sample of Male Firearm Owners.

Previous research has linked unsafe firearm storage practices and other ownership-related characteristics to key factors that facilitate the transition from suicidal thoughts to suicidal behaviors (i.e., acquired capability for suicide). This research has not investigated the extent to which firearm owners store firearms in their vehicles, a factor that increases ready access to the most lethal means of suicide. OBJECTIVE: This cross-sectional study investigated the prevalence of occasional and permanent vehicle firearm storage as well as demographic and psychological correlates of this practice in a sample of N = 408 adult male firearm owners oversampled for historical thoughts of suicide. METHODS: Participants completed an online survey for monetary compensation. RESULTS: Over 40% of participants indicated at least occasionally storing firearms in their vehicles with over 15% indicating storage of firearms unlocked and loaded. Elevated scores on measures of negative affect, worry, intolerance of uncertainty, and historical suicidal thoughts and behaviors were seen in those who endorsed vehicle firearm storage compared to those who did not. CONCLUSION: Individual and public health firearm safety strategies would benefit from an explicit focus on the transition of firearms to and from one's vehicle.HIGHLIGHTSOver 40% of male firearm owners at least occasionally store a firearm in a vehicle.15% of those who store a firearm in a vehicle do so unlocked and loaded.Suicidal thought severity was related to storing a firearm in a vehicle.Historical suicidal behaviors were related to storing a firearm in a vehicle.

Sonoreperfusion therapy for microvascular obstruction: A step toward clinical translation.

Sonoreperfusion therapy is being developed as an intervention for the treatment of microvascular obstruction. We investigated the reperfusion efficacy of two clinical ultrasound systems (a modified Philips EPIQ and a Philips Sonos 7500) in a rat hindlimb microvascular obstruction model. Four ultrasound conditions were tested using 20 min treatments: Sonos single frame, Sonos multi-frame, EPIQ low pressure and EPIQ high pressure. Contrast-enhanced perfusion imaging of the microvasculature was conducted at baseline and after treatment to calculate microvascular blood volume (MBV). EPIQ high pressure treatment resulted in significant recovery of MBV from microvascular obstruction, returning to baseline levels after treatment. EPIQ low pressure and Sonos multi-frame treatment resulted in significantly improved MBV after treatment but below baseline levels. Sonos single-frame and control groups showed no improvement post-treatment. This study demonstrates that the most effective sonoreperfusion therapy occurs at high acoustic pressure coupled with high acoustic intensity. Moreover, a clinically available ultrasound system is readily capable of delivering these effective therapeutic pulses.

Principles of cerebral ultrasound contrast imaging.

Ultrasound contrast is gaining acceptance worldwide as an adjunct to conventional ultrasound imaging. It has clinical applications as diverse as liver disease detection and characterization, myocardial perfusion and wall motion studies, and imaging of cerebral vascularity and perfusion. This paper will focus on imaging techniques used for transcranial ultrasound contrast imaging. The interaction of ultrasound with the microbubbles in the contrast agent is complex and nonlinear. This has led to the development of a variety of imaging modes to improve contrast detection compared with non-contrast optimized modes. This article presents several of these imaging methods in such a way as to help users of ultrasound contrast in the clinic and in research to understand this rapidly developing field.

Prehospital stroke diagnosis and treatment in ambulances and helicopters-a concept paper.

Stroke is the second common cause of death and the primary cause of early invalidity worldwide. Different from other diseases is the time sensitivity related to stroke. In case of an ischemic event occluding a brain artery, 2000000 neurons die every minute. Stroke diagnosis and treatment should be initiated at the earliest time point possible, preferably at the site or during patient transport. Portable ultrasound has been used for prehospital diagnosis for applications other than stroke, and its acceptance as a valuable diagnostic tool "in the field" is growing. The intrahospital use of transcranial ultrasound for stroke diagnosis has been described extensively in the literature. Beyond its diagnostic use, first clinical trials as well as numerous preclinical work demonstrate that ultrasound can be used to accelerate clot lysis (sonothrombolysis) in presence as well as in absence of tissue plasminogen activator. Hence, the use of transcranial ultrasound for diagnosis and possibly treatment of stroke bares the potential to add to current stroke care paradigms significantly. The purpose of this concept article is to describe the opportunities presented by recent advances in transcranial ultrasound to diagnose and potentially treat large vessel embolic stroke in the prehospital environment.

Effects of attenuation and thrombus age on the success of ultrasound and microbubble-mediated thrombus dissolution.

The purpose of this study was to examine the effects of applied mechanical index, incident angle, attenuation and thrombus age on the ability of 2-D vs. 3-D diagnostic ultrasound and microbubbles to dissolve thrombi. A total of 180 occlusive porcine arterial thrombi of varying age (3 or 6 h) were examined in a flow system. A tissue-mimicking phantom of varying thickness (5 to 10 cm) was placed over the thrombosed vessel and the 2-D or 3-D diagnostic transducer aligned with the thrombosed vessel using a positioning system. Diluted lipid-encapsulated microbubbles were infused during ultrasound application. Percent thrombus dissolution (%TD) was calculated by comparison of clot mass before and after treatment. Both 2-D and 3-D-guided ultrasound increased %TD compared with microbubbles alone, but %TD achieved with 6-h-old thrombi was significantly less than 3-h-old thrombi. Thrombus dissolution was achieved at 10 cm tissue-mimicking depths, even without inertial cavitation. In conclusion, diagnostic 2-D or 3-D ultrasound can dissolve thrombi with intravenous nontargeted microbubbles, even at tissue attenuation distances of up to 10 cm. This treatment modality is less effective, however, for older aged thrombi.

Medical ultrasound systems.

Medical ultrasound imaging has advanced dramatically since its introduction only a few decades ago. This paper provides a short historical background, and then briefly describes many of the system features and concepts required in a modern commercial ultrasound system. The topics addressed include array beam formation, steering and focusing; array and matrix transducers; echo image formation; tissue harmonic imaging; speckle reduction through frequency and spatial compounding, and image processing; tissue aberration; Doppler flow detection; and system architectures. It then describes some of the more practical aspects of ultrasound system design necessary to be taken into account for today's marketplace. It finally discusses the recent explosion of portable and handheld devices and their potential to expand the clinical footprint of ultrasound into regions of the world where medical care is practically non-existent. Throughout the article reference is made to ways in which ultrasound imaging has benefited from advances in the commercial electronics industry. It is meant to be an overview of the field as an introduction to other more detailed papers in this special issue.

Principles of cerebral ultrasound contrast imaging.

Ultrasound contrast is gaining acceptance worldwide as an adjunct to conventional ultrasound imaging. It has clinical applications as diverse as liver disease detection and characterization, myocardial perfusion and wall motion studies, and cerebral vascularity and perfusion imaging. This paper will focus on imaging techniques used for transcranial ultrasound contrast imaging. The interaction of ultrasound with the microbubbles in the contrast agent is complex and nonlinear. This has led to the development of a variety of imaging modes to improve contrast detection over noncontrast optimized modes. This article presents several of these imaging methods in such a way as to help clinical and research users of ultrasound contrast understand this rapidly developing field.

Vascular flow and perfusion imaging with ultrasound contrast agents.

Current techniques for imaging ultrasound (US) contrast agents (UCA) make no distinction between low-velocity microbubbles in the microcirculation and higher-velocity microbubbles in the larger vasculature. A combination of radiofrequency (RF) and Doppler filtering on a low mechanical index (MI) pulse inversion acquisition is presented that differentiates low-velocity microbubbles (on the order of mm/s) associated with perfusion, from the higher-velocity microbubbles (on the order of cm/s) in larger vessels. In vitro experiments demonstrate the ability to separate vascular flow using both harmonic and fundamental Doppler signals. Fundamental and harmonic Doppler signals from microbubbles using a low-MI pulse-inversion acquisition are compared with conventional color Doppler signals in vivo. Due to the lower transmit amplitude and enhanced backscatter from microbubbles, the in vivo signal to clutter ratios for both the fundamental (-11 dB) and harmonic (-4 dB) vascular flow signals were greater than with conventional power Doppler (-51 dB) without contrast agent. The processing investigated here, in parallel with conventional pulse-inversion processing, enables the simultaneous display of both perfusion and vascular flow. In vivo results demonstrating the feasibility and potential utility of the real-time display of both perfusion and vascular flow using US contrast agents are presented and discussed.

Ultrasound contrast imaging research.

This article is a review of the research on ultrasound contrast agents in general imaging. While general imaging contrast agent applications are still undergoing investigation and waiting FDA approval in the United States, they are approved for clinical use in Europe and other countries. The contrast microbubble properties are described, including their nonlinear behavior and destruction properties. Imaging techniques like harmonic imaging, pulse inversion, power pulse inversion, agent detection imaging, microvascular imaging, and flash contrast imaging are explained. A connection is made between the aforementioned imaging techniques and the different contrast agents available. The blood flow appearance of different liver tumors in the presence of contrast agents is demonstrated with examples.

Improvement in Endocardial Border Delineation Using Tissue Harmonic Imaging.

BACKGROUND AND METHODS: For years, tissue has been assumed to be a linear medium in diagnostic ultrasound applications; thus, no backscattered signals in the second harmonic band are expected in harmonic imaging without the injection of a contrast agent. However, it has been shown that a useful tissue image is formed even without a contrast agent. The aim of this study was to evaluate whether this tissue harmonic image provided improved visualization of endocardial borders. Fifty-six adult patients with various heart diseases were investigated using conventional two-dimensional echocardiography and tissue harmonic imaging. In 30 of these patients, the left ventricular endocardial borders were well defined in the standard parasternal and apical views using conventional two-dimensional echocardiography. In the remaining 26 patients, delineation of endocardial borders was not possible in at least two segments. The equipment used was an ATL HDI-3000 diagnostic system equipped with harmonic imaging. RESULTS: In all 56 patients, the myocardium and valves could be imaged with tissue harmonic imaging. Harmonic recordings were sharper and contained fewer clutter artifacts than conventional recordings. Most striking was the enhancement of left ventricular endocardial borders. In the 26 patients with incomplete delineation of left ventricular endocardial borders, wall motion could be evaluated in 290 of 312 (93%) segments with tissue harmonic imaging compared with only 168 of 312 (54%) segments with conventional echocardiography (P < 0.001). CONCLUSIONS: Tissue harmonic imaging improves image quality and can be used to enhance the definition of left ventricular endocardial borders. These findings can be explained by the nonlinear propagation of ultrasound within the tissue, which results in distortion of the transmitted signal and, thus, harmonic generation.