scholarly journals Combination of microbubbles and diagnostic ultrasound at a high mechanical index for the synergistic microwave ablation of tumours

2016 ◽  
Vol 33 (3) ◽  
pp. 318-326 ◽  
Author(s):  
Jinshun Xu ◽  
Yang Cao ◽  
Chunyan Xu ◽  
Xueqing Cheng ◽  
Yufeng You ◽  
...  
Keyword(s):  
Microwave Ablation ◽  
Diagnostic Ultrasound ◽  
Mechanical Index

scholarly journals Diagnostic Ultrasound Safety

2014 ◽  
Vol 8 (2) ◽  
pp. 178-183 ◽  
Author(s):  
Kazuo Maeda
Keyword(s):  
Obstet Gynecol ◽  
Physical Property ◽  
Diagnostic Ultrasound ◽  
Mechanical Effect ◽  
Mechanical Index ◽  
Pulsed Doppler ◽  
Output Intensity ◽  
Thermal Index ◽  
4D Ultrasound ◽  
Pulsed Doppler Ultrasound

ABSTRACT Ultrasound bioeffect is discussed from its physical property, i.e. thermal effect by thermal index, mechanical effect by mechanical index, and by the output intensity of ultrasound. Generally, thermal and mechanical indices should be lower than 1 in obstetrical setting, and threshold output intensity of no bioeffect is lower than SPTA 240 mW/cm2 in pulse wave. Pulsed Doppler ultrasound thermal and mechanical indices should be also lower than 1, and should be carefully used it in 11 to 13+6 weeks of pregnancy. Real-time B-mode, transvaginal scan, pulsed Doppler, 3D and 4D ultrasound were separately discussed in the ultrasound safety. Generally diagnostic ultrasound is safe for the fetus and embryo, if thermal and mechanical indices are lower than 1, and ultrasound devices are safe, if it is used under official limitation, e.g. the output intensity is less than SPTA 10 mW/cm2 in Japan. The ultrasound user is responsible ultrasound safety, e.g. higher thermal and mechanical indices than 1 should be lowered to be lower than 1, controlling the device output intensity. The user should learn bioeffects of ultrasound and prudent use of ultrasound under the ALARA principle. How to cite this article Maeda K, Kurjak A. Diagnostic Ultrasound Safety. Donald School J Ultrasound Obstet Gynecol 2014;8(2):178-183.

scholarly journals Diagnostic Ultrasound High Mechanical Index Impulses Restore Microvascular Flow in Peripheral Arterial Thromboembolism

2016 ◽  
Vol 42 (7) ◽  
pp. 1531-1540 ◽  
Author(s):  
Thomas R. Porter ◽  
Stanley Radio ◽  
John Lof ◽  
Carr Everbach ◽  
Jeffry E. Powers ◽  
...  
Keyword(s):  
Diagnostic Ultrasound ◽  
Mechanical Index ◽  
Arterial Thromboembolism ◽  
Microvascular Flow ◽  
Peripheral Arterial

Therapeutic effect of diagnostic ultrasound on enzymatic thrombolysis

2004 ◽  
Vol 91 (06) ◽  
pp. 1078-1083 ◽  
Author(s):  
Cristiana Lupi ◽  
Guido Lazzerini ◽  
Piero Chiarelli ◽  
Antonio L’Abbate ◽  
Daniele Rovai ◽  
...  
Keyword(s):  
Venous Blood ◽  
Normal Subjects ◽  
Vascular Wall ◽  
Diagnostic Ultrasound ◽  
In Vitro Models ◽  
Mechanical Index ◽  
Ultrasound Exposure ◽  
Tissue Plasminogen ◽  
Artery Disease

SummaryIf delivered at elevated intensity, ultrasound potentiates enzymatic clot dissolution; however, an elevated acoustic intensity damages vascular wall and favors reocclusion. This study’s aim was to investigate whether exposure to high-frequency, lowintensity ultrasound generated by a diagnostic scanner enhances enzymatic thrombolysis, and if this effect differs in clots from blood of normal subjects and of patients with coronary artery disease (CAD). Venous blood samples were drawn from 10 healthy volunteers and from 10 CAD patients on chronic medical treatment, which also included aspirin. Each sample generated 2 radiolabelled clots, which were positioned in 2 in vitro models filled with human plasma recirculating at 37°. One clot was exposed to acetyl salicylic acid (60 μg/ml), tissue plasminogen activator (3 μg/ml) and heparin (1 IU/ml), while the other was exposed to the same medications plus ultrasound (2.5 MHz, mechanical index = 1.0) for 3 hours. Enzymatic thrombolysis was measured as solubilization of radiolabel. Normal subjects and patients did not significantly differ as to coagulation parameters, weight, volume and density of the clots, and fibrinolytic activity (p = 0.794). Ultrasound exposure did not influence thrombolysis in clots of normal subjects (p = 0.367), while it enhanced the dissolution of clots of CAD patients (p = 0.013). The enhancement was equal to 51% at 5 minutes, 32% at 15 minutes, 27% at 30 minutes, 20% at 1 hour and 19% at 3 hours (p < 0.05). Diagnostic ultrasound enhances enzymatic dissolution of clots generated from the blood of CAD patients, likely due to chronic treatment and in particular to aspirin.

scholarly journals Safety of Transvaginal Scan Estimated from Ultrasonic Bioeffects

2017 ◽  
Vol 11 (1) ◽  
pp. 1-6
Author(s):  
Kazuo Maeda
Keyword(s):  
Cell Growth ◽  
Negative Pressure ◽  
Fetal Tissue ◽  
Biological Tissues ◽  
Diagnostic Ultrasound ◽  
Ultrasound Wave ◽  
Mechanical Index ◽  
Output Intensity ◽  
Thermal Status ◽  
Excess Heating

ABSTRACT The embryo and fetus are generally studied using ultrasound imaging in pregnancy; however, ultrasound wave is absorbed by biological tissues to elevate the temperature. The growing embryonic and fetal tissue tends to be damaged by heating; thus, excess heating that damages young sensitive growing tissue should be prevented in ultrasound diagnosis. Hence, the thermal status of diagnostic ultrasound should be known with thermal index (TI), of which the determination and application are discussed in this chapter. Peculiar problem to transvaginal scan and thermal problem in febrile patient are discussed. Additionally, the cavitation, which is related with negative pressure, develops high pressure, high temperature, and free radicals that damage embryonic and fetal tissues. Therefore, the mechanical index (MI) has to be determined, measuring negative pressure of ultrasound. The MI is determined for the safety of diagnostic ultrasound. The ultrasound device output intensity that suppresses fetal amniotic JTC-3 cultured cell growth was determined, where 240 mW/cm2 or less output intensity did not suppress the cell growth, namely, the diagnostic ultrasound has no bioeffect when the output is lower than 240 mW/cm3. The as low as reasonably achievable principle in the Doppler method of 0.1 TI will be discussed. Three experimental reports of hazardous effects of ultrasound are discussed. How to cite this article Maeda K. Safety of Transvaginal Scan Estimated from Ultrasonic Bioeffects. Donald School J Ultrasound Obstet Gynecol 2017;11(1):1-6.

Abstract 14082: The Effect of Diagnostic Ultrasound Mediated High Mechanical Impulses on Cardiac Output During an Ultrasound Enhancing Agent Infusion

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Swethika Sundaravel ◽  
Jessica Roettger ◽  
Arif Albulushi ◽  
Joan Olson ◽  
Feng Xie ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Contrast Echocardiography ◽  
Diagnostic Ultrasound ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Mechanical Index ◽  
Endocardial Border ◽  
Ventricular Ejection Fraction ◽  
The Impact

Introduction: Diagnostic ultrasound high mechanical index (MI) impulses are used during an ultrasound enhancing agent (UEA) infusion to improve endocardial border resolution and study myocardial perfusion. They have also been shown to cause endothelial shear, resulting in prolonged increases in ATP release and augment microvascular flow. The potential for these high MI impulses to alter cardiac output (CO) are unknown. Hypothesis: To study the impact of high MI impulses on CO Methods: Fifty one patients (mean age 63±15 years; 41% female) referred for contrast echocardiography underwent very low MI imaging with intermittent high MI impulses (1.6-1.7 Megahertz) in three different apical windows during either a Definity (Lantheus Medical) or Lumason (Bracco Diagnostics) infusion or bolus. CO was determined from Doppler measurements of left ventricular outflow tract stroke volume and heart rate. Mean contrast enhanced biplane left ventricular ejection fraction (LVEF) was 53±15%; (range 10-75%). CO from baseline without contrast (COwoC) and baseline after contrast (COwC) before high MI impulses were compared to CO after contrast and after high MI impulses (COaHMI). All CO measurements were made by an independent reviewer blinded to time of measurement (before or after high MI impulses). Results: Although heart rate did not change before and after intermittent high MI impulse administration, COaHMI increased significantly when compared to COwoC and COwC (p< 0.001 for both comparisons; Figure). In nine patients (18%), CO increased by more than 20%. In patients with LVEF < 40% COwC was 2.4±0.8 liters per minute (LPM) and COaHMI increased to 2.7± 0.8 LPM (p=0001). In patients with LVEF≥40%, COwC was 3.4±1.06 LPM while COaHMI increased to 3.8± 1.2 LPM (p=0.00001). Conclusions: Application of diagnostic guided high MI impulses during a commercially available microbubble infusion significantly increases CO irrespective of underlying left ventricular systolic function.

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