Title Fizikalni principi medicinske primjene doplera
Title (english) Physical principles of Doppler ultrasonography
Author Nikola Kočet
Mentor Sanja Dolanski-Babić (mentor)
Committee member Jelena Popić Ramač (predsjednik povjerenstva)
Committee member Ljiljana Šerman (član povjerenstva)
Committee member Sanja Dolanski-Babić (član povjerenstva)
Granter University of Zagreb School of Medicine (Department of Physics and Biophysics) Zagreb
Defense date and country 2015-07-15, Croatia
Scientific / art field, discipline and subdiscipline BIOMEDICINE AND HEALTHCARE Basic Medical Sciences
Abstract Dopplerov efekt ima široku primjenu u gotovo svim granama medicine, počevši od radiologije, preko ginekologije i ortopedije, pa sve do interne medicine. Općenito govoreći, Dopplerov efekt je promjena frekvencije zvuka, svjetlosti ili drugih valova, prouzročena relativnim kretanjem izvora valova, odnosno emitera i prijemnika. Primjena Dopplerovog efekta u medicini se temelji na razlici frekvencija između emitiranih i detektiranih ultrazvučnih valova, dobivenih refleksijom ultrazvuka na eritrocitima. Primjenjuje se na način da se ultrazvučni snop usmjeri prema krvnoj žili te pritom analiziraju Dopplerovi pomaci ultrazvuka raspršenog na eritrocitima. Na taj način nastaje slika strujanja krvi, koja se prikazuje koristeći audio prikaz, spektralnu frekvencijsku analizu te doplerove indekse. Prilikom primjene doplera mogu nastati različiti artefakti koji se uklanjaju optimizacijom doplerovog prikaza. Danas je u uporabi nekoliko doplerskih tehnika od kojih su najznačajnije kontinuirani i pulsirajući dopler, te obojeni i power dopler. Ultrazvučni intenziteti koji se dobivaju primjenom doplera daleko nadmašuju one kod konvencionalnog B-mod ultrazvuka. Prema preporukama američke FDA treba težiti smanjenju intenziteta i vremena izlaganja ultrazvučnom snopu, dok je Nacionalni Savjet za zaštitu od zračenja SAD-a stava da korist od primjene ultrazvuka daleko premašuje pretpostavljene rizike.
Abstract (english) The Doppler efect is widely used in almost all fields of medicine, starting from radiology, through gynecology and orthopedics, to internal medicine. Generally speaking, the Doppler effect is a change in the frequency of sound, light or other waves, caused by the relative movement of the source of the waves, i.e. emitters and receivers. The use of the Doppler effect in medicine is based on the difference between the frequencies of emitted and detected sound waves obtained by the reflection of ultrasound on erythrocytes. It is used in a way that the ultrasound beam is directed towards a blood vessel and thereby analyze the Doppler shifts of ultrasound waves scattered across the erythrocytes are being analyzed. In this way, there occurs a picture of blood flow presented using audio display, spectral frequency analysis and Doppler indices. During Doppler use various artifacts may appear but are removed by optimizing the Doppler display. Several Doppler techniques are in use today, most important of which are continuous and pulsed Doppler as well as colored and power Doppler. The ultrasound intensities are obtained by using Doppler far exceed those of a conventional B-mode ultrasound. According to the recommendations of the US FDA, one should strive to decrease the intensity and exposure time of the ultrasound beam, while the National Council for Radiation Protection of the United States officially considered that the benefits of ultrasound use surpass assumed risks.
Keywords
Dopplerov efekt
Dopplerovi pomaci
eritrociti
audio prikaz
spektralna frekvencijska analiza
doplerovi indeksi
artefakti
kontinuirani i pulsirajući dopler
obojeni i power dopler
Keywords (english)
Doppler effect
Doppler shifts
erythrocytes
audio display
spectral frequency analysis
Doppler indices
artifacts
continuous and pulsed Doppler
colored and power Doppler Doppler effect
Doppler shifts
erythrocytes
audio display
spectral frequency analysis
Doppler indices
artifacts
continuous and pulsed Doppler
colored and power Doppler Doppler effect
Doppler shifts
erythrocytes
audio display
spectral frequency analysis
Doppler indices
artifacts
continuous and pulsed Doppler
colored and power Doppler
Language croatian
URN:NBN urn:nbn:hr:105:437651
Study programme Title: Medicine Study programme type: university Study level: integrated undergraduate and graduate Academic / professional title: doktor/doktorica medicine (doktor/doktorica medicine)
Type of resource Text
File origin Born digital
Access conditions Open access
Terms of use
Created on 2016-08-12 08:39:10