Fizikalni principi medicinske primjene doplera

master's thesis

• 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
• Created on: 2016-08-12 08:39:10