Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography
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J Am Soc Echocardiogr · Jul 1995
Comparative Study Clinical TrialNew miniaturized versus conventional biplane transesophageal transducers: recent clinical experience in adults.
A subset of patients have substantial discomfort on examination with transesophageal echocardiography with the conventional probe, whereby the dimensions of the probe play a decisive role. Miniaturized biplane transducers have recently become available (2 x 32 channels, dimensions 9.5 x 8.7 mm, and circumference approximately 30% less than the conventional echoscope) and allow ultrasound examination at 3.5, 5.0 and 7.0 MHz. A prospective study was carried out in 90 patients to compare difficulties on insertion of the probe, subjective evaluation by the patient during examination, and the two-dimensional image, as well as Doppler and color-coded Doppler quality of the miniaturized biplane versus the conventional probe. ⋯ With transmit/receive frequency of 7.0 MHz, however, image resolution was excellent in the near field of 5 cm and nearly equivalent to that of the conventional probe (5.0 MHz). Pulsed-wave and continuous wave Doppler and color-coded Doppler information from both probes was similar in quality. Whenever examination with a conventional transesophageal transducer promises to be difficult, or when sedation is contraindicated because of a severe illness or respiratory insufficiency, transesophageal echocardiography should be considered with a smaller biplane probe at higher transmit-receive frequencies.