IMPORTANCE OF ROENTGEN TUBE ANGLES IN CINEFLUOROSCOPIC INVESTIGATION OF MECHANICAL PROSTHESES

Aim. We planned a cinefluoroscopy (CF) study to mark the ideal opening and closing tube angles for mitral and aortic positioned mechanical valves. Our hypothesis was that if we find an intensity zone where the valves were optimally seen, then starting the CF examination from that tube position would shorten the examination duration

Material and methods. Between January 2010 and August 2011, 192 consecutive patients (mean age 51,86±12,80 years; 101 women and 91 male) with mitral (n=135; monoleaflet: 37; bileaflet: 98) and aortic (n=87; monoleaflet:19; bileaflet: 68) and tricuspid (n=3; all bileaflet) prostheses were enrolled into the study. Cinefluoroscopy was performed with Philips Radiologic System. For each type and location of mechanical prostheses optimal opening-closing angles obtained and marked on x-y axis graphic. Furthermore, we investigated whether there is an intensity zone quadrant.

Results. Among patients with prosthetic bileaflet mitral valve in supine position optimal images were obtained: 34 (58,6%) patients were in RAO-Cranial, 12 (20,7%) were in left anterior oblique (LAO) cranial, 7 (12,1%) were in RAO caudal and 5 (8,6%) were in LAO caudal angles. Among patients with prosthetic bileaflet aortic valves in supine position shown: 27 (50%) patients were in LAO-cranial, 10 (18,5%) were in RAO- cranial, 9 (16,7%) were in LAO-caudal and 8 (14,8%) patients were in RAO-caudal angles.

Conclusion. According to our results it seems logical to start mitral position CF assessment by RAO-Cranial angles quadrant and for aortic position by LAO-Cranial angles quadrant to decrease time and lower radiation exposure.

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