[Radiation burden in invasive cardiac diagnosis: extent, factors of influence and references for minimizing radiation dosage].

Despite great effort concerning quality control in diagnostic radiology, there exist only a few studies giving reliable details about x-ray exposure during heart-catheterization. The mean radiation dose-area product of 100 patients (male 65%, middle-aged 60.7 +/- 10.4 years) investigated was irrespective the technique according to Sones or Judkins 45.2 +/- 14.7 Sv x cm2. In comparison to an optimated x-ray chest the local x-ray entrance-expositions in case of changing (90 mSv) and constant (300 mSv) projections were 300- and 1000-fold respectively. Concerning the dose-area product and the effective dose the multiplicative factor reached 160 and 100 respectively. Radiation entrance-exposure during cinematography was 15-fold as during x-ray-examination sequences. The cinematographic radiation dose was influenced significantly by location of the contrasted coronary artery (p < 0.001) and plane of projection (p < 0.001): intensive in entrance surface dose were projections x-raying spinal column and sternum (RCA in PA- and LCA in LAO-projection). Independent variables were body mass index (BMI, p < 0.001) and sex (p < 0.005), but not age. X-ray-dose of heart catheterization was lower in women than in men, this fact being only significant in the elderly (> 60 years), indicating an effect of postmenopausal osteoporosis. An effective minimization of x-ray exposition in heart catheterization can be realized by avoiding needless cine-sequences (25-35%), rotating out bone structures of the x-ray beam ( < or = 22%) and reduction of overweight (BMI 35 > 23 kg/m2: 25-35%).