[Pictocam instead of Pictogram - a quality improvement study in abdominal ultrasound imaging]. / Piktocam statt Piktogramm - Validierungsstudie zur Qualitätsverbesserung der Bilddokumentation beim abdominellen Ultraschall.

AIM: To replace pictograms with pictocam pictures: A prospective blinded quality improvement study in documenting image orientation and localisation in abdominal ultrasound imaging. MATERIALS AND METHODS: A minicam was mounted on the ultrasound scanhead to record pictocam pictures. The primary examiner produced an ultrasound image together with the routinely embedded pictogram. Subsequently the pictogram was covered by the synchronically taken pictocam picture. Subsequently, the primary examiner assessed the pictograms and the second examiner the pictocam pictures (blinded to the pictogram findings of the primary examiner). RESULTS: A total of 679 paired pictogram and pictocam pictures were available from 114 patients. The localisation of the utrasound head showed an absolute or close agreement of 99.7% (677/679) with a 95% confidence interval of [98.94%-99.96%]. The angle of the ultrasound head showed an absolute or close agreement of 99.0% (672/679) with a 95% confidence interval of [97.98% - 99.58%]. CONCLUSION: This study shows that the pictogram can validely be replaced by a pictocam picture. The routine addition of a minicam to the ultrasound scanhead would thus not only improve the quality of the documentation, but would also result in time savings during examinations.

Influence of ultrasound operating parameters on ultrasound-induced thrombolysis in vitro.

The effect of operating parameters on the thrombolytic potency of ultrasound (US) is important for potential therapeutic applications, but is not fully understood. Fresh human whole-blood thrombi were exposed in vitro to focused US from a diagnostic transducer driven by an impulse generator via an amplifier to vary duration (10 to 60 min), intensity (7 to 90 W/cm(2)), frequency (2 to 4.5 MHz), pulsed wave duty cycle (1:5 to 1:100 and continuous wave mode) and pulse length (100 to 400 micros). Segments of thrombi (498 +/- 73 mg) were submersed and insonated in saline solution. Thrombolytic efficiency was expressed as percentage loss of mass compared with controls (noninsonified thrombi). Ultrasound exposure achieved a significantly higher thrombolysis than no US, 56 +/- 16 % vs. 29 +/- 11 % (n = 232, p < 10(-6)). There was an exponential saturation-type correlation with duration of insonation (r(2) = 0.64) and intensity (r(2) = 0.97), an inverse correlation with US frequency at matched intensities (r(2) = 0.76, p < 10(-5)), a logarithmic relationship with duty cycle in pulsed mode (r(2) = 0.86) and a modest direct effect of pulse length (r(2) = 0.57, p < 10(-5)). Thus, thrombolytic efficiency of US depends directly on duration, intensity, duty cycle and pulse length and inversely, on frequency.