Intracardiac ultrasound

FIGURE 6.7 Intracardiac ultrasound (A) shows the left atrium (LA) imaged from a phased array transducer in the right atrium. A contour of the LA is incorporated into an electroanatomical map (B) and also merged with a preacquired Computed tomographic angiogram. 

Fig. 5 J Intracardiac Ultrasound for Vascular Access. Use of vascular ultrasound to gain access to the axillary vein can greatly facihtate left ventricular lead implantation by improving vascular access at the beginning of the procedure. Typical ultrasound probes have frequencies of 7.5 or 9 MHz (a). The higher frequency probes are better for access for more superficial vascular structures like those in the neck, whereas the lower frequency 7.5 MHz transducers permit acceptable imaging of the axillary, cephahc and portions of the subclavian veins. Ultrasound gel must be placed inside the plastic probe cover to gain acceptable images (b, Panel A). The plastic cover is secured with sterile rubber bands (b, Panel B). To differentiate to the axillary vein (V) from artery (A), gentle compression is applied to the vessels, causing the vein to collapse while the artery does not (c).

Intracardiac echocardiography is emerging as an ideal real-time modality to guide intracardiac interventional procedures. ICE allows accurate appreciation of cardiac anatomy and detailed visualization of specific anatomic structures, the most important factors in planning and guiding catheter-based interventional techniques [15-17]. In our daily practice, ICE is performed using a commercially available 9-F/9 MHz ultra-ICE catheter-based ultrasound transducer (EP Technologies, Boston Scientific, San Jose, CA, USA). The Ultra ICE catheter is introduced percutaneously into the... 

Schwartz SL, Gillam LD,Weintraub AR et al (1993) Intracardiac echocardiography in humans using a smallsized (6F), low frequency (12.5 MHz) ultrasound catheter. J Am Coll Cardiol 21 189-198... 

CMUTs have the potential to make ultrasound a far more versatile and important imaging modality. This technology has made advances in acoustic matching and the microminiaturization of electronics. It enables higher-frequency imaging, allows clinicians to view small features in the body, and is useful for ultrasound imaging especially in the area of volumetric in vivo imaging, intravascular, and intracardiac research. 

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