4-D ICE: A 2-D Array Transducer With Integrated ASIC in a 10-Fr Catheter for Real-Time 3-D Intracardiac Echocardiography.

We developed a 2.5 ×6.6 mm 2 2 -D array transducer with integrated transmit/receive application-specific integrated circuit (ASIC) for real-time 3-D intracardiac echocardiography (4-D ICE) applications. The ASIC and transducer design were optimized so that the high-voltage transmit, low-voltage time-gain control and preamp, subaperture beamformer, and digital control circuits for each transducer element all fit within the 0.019-mm 2 area of the element. The transducer assembly was deployed in a 10-Fr (3.3-mm diameter) catheter, integrated with a GE Vivid E9 ultrasound imaging system, and evaluated in three preclinical studies. The 2-D image quality and imaging modes were comparable to commercial 2-D ICE catheters. The 4-D field of view was at least 90 ° ×60 ° ×8 cm and could be imaged at 30 vol/s, sufficient to visualize cardiac anatomy and other diagnostic and therapy catheters. 4-D ICE should significantly reduce X-ray fluoroscopy use and dose during electrophysiology ablation procedures. 4-D ICE may be able to replace transesophageal echocardiography (TEE), and the associated risks and costs of general anesthesia, for guidance of some structural heart procedures.

Deep sedation for cardiac magnetic resonance imaging: a comparison with cardiac anesthesia.

OBJECTIVE: To test the hypothesis that safety, efficacy, and image quality in pediatric patients who undergo deep sedation for cardiac magnetic resonance imaging (CMR) for congenital heart disease (CHD) is similar to general anesthesia (GA). STUDY DESIGN: Retrospective review of all CMR records from 1997-2006. Six hundred sixty patients underwent deep sedation (DS) and 161 underwent GA. Statistics included analysis of variance, chi(2) analysis, and the coefficient of variation. RESULTS: Diagnoses included a broad spectrum of CHD. No serious adverse events (AE) including mortalities and hospitalizations occurred because of DS. There were 18 (2.8%) self-limited events in the DS group with a success rate of 97.9%. The AE rate for patients undergoing GA was 3.9% (n = 6), including 2 overnight hospital stays with a success rate of 100%. AE and success rates did not differ between the 2 groups. Observers blinded to the patient's group found no difference in image quality. Even in young infants, excellent image quality was obtained. CONCLUSIONS: Sedation of appropriately screened pediatric patients with CHD undergoing CMR is safe and well tolerated and yields high-quality images similar to GA. GA should be considered for patients with CHD with hemodynamic or airway compromise, in whom sedation has failed, or who have special circumstances.