Author/Editor		Obad-Kovačević, Dragica; Brnić, Zoran; Hebrang, Andrija
Title		Mammographic oblique views 45 degrees versus 60 degrees: breast thickness, breast exposure and image quality
Translated title		Primerjava debeline dojke, izpostavljenosti sevanju in kakvosti slik pri uporabi polstranskih mamografskih projekcij pod kotoma 45 stopinj in 60 stopinj
Type		članek
Source		Radiol Oncol
Vol. and No.		Letnik 37, št. 1
Publication year		2003
Volume		str. 5-8
Language		eng
Abstract		Background. Standard screening mammography includes two views: craniocaudal and mediolateral oblique. In the mediolateral oblique projection a central beam angle can varies between 30° and 60°. Patients and methods. We compare the thickness of the compressed breast, time-current product, exposures and image quality in two different mammographic oblique views: 45° versus 60°. Our study population consisted of 33 women in whom additional 60° films after standard 45° films were obtained for the objective diagnostic reasons. Results. The mean thickness of the compressed breast was significantly lower with an angle of 60° than with an angle of 45° (47.8 vs. 50.7 mm, p<0.01); the mean time current product and the mean breast exposure were significantly lower with an angle of 60° than with an angle of 45° (42.6 vs. 46.7 mAs, p<0.01; 0.67 vs. 0.78 mGy, p<0,01). The difference in the image quality has not reached statisticaI significance (but it exists!). Conclusions. By introducing 60° films instead of commonly used 45° films, mammograms of at least the same quality can be obtained with lower radiation dose, which is of great importance when we remind the great radiosensitivity of glandular breast tissue.
Summary		Izhodišča. Pri standardnem presejalnem testu z mamografijo uporabljamo dvoje projekcij: kraniokavdalno in mediolateralno polstransko. Pri mediolateralni polstranski projekciji je kot centralnega žarka od 30° do 60°. Bolniki in metode. Primerjali smo debelino komprimirane dojke, zmnožek časa in električnega toka, izpostavljenost sevanju in kakovost slik pri dveh različnih mamografskih poševnih projekcijah: pod kotoma 45° in 60°. Preiskave smo naredili pri 33 ženskah, pri katerih smo zaradi diagnostičnih zahtev poleg slikanja pod kotom 45° naredili tudi slikanje pod kotom 60°. Rezultati. Srednja vrednost debeline komprimirane dojke je bila pri slikanju pod kotom 60° statistično značilno nižja kot pod kotom 45° (47,8 vs. 50,7 mm, p<0.01); pravtako sta bili tudi statistično značilno nižji srednji vrednosti zmnoška časa in eletričnega toka ter izpostavljenosti sevanju (42,6 vs. 46,7 mAs, p<0.01; 0,67 vs. 0,78 mGy, p<0.01). Našli smo tudi razliko v kakovosti slik, ki pa ni bila statistično značilno boljša. Zaključki. Z uporabo polstranske mamografske projekcije pod kotom 60°smo dosegli vsaj enako kakovost mamografskih slik ob nižji sevalni dozi, kar je zelo pomembno, saj je mlečna žleza v dojki zelo radiosenzitivna.
Descriptors		BREAST DISEASES MAMMOGRAPHY RADIATION DOSAGE RADIATION MONITORING THERMOLUMINESCENT DOSIMETRY FILM DOSIMETRY