Cardiac magnetic resonance: patient preparation and setup, pulse sequence and imaging parameters selection, slice orientation

Uvod: Bolezni srca predstavljajo pomemben delež povzročiteljev smrtnosti in obolevnosti v razvitem svetu. Slikovna obravnava srca je ključnega pomena pri zgodnjem odkrivanju in opredelitvi nepravilnosti na njem. Magnetno resonančno (MR) slikanje na področju kardiološke diagnostike doživlja obsežen razvoj. Namen: Želeli smo ugotoviti, kako razpoložljiva literatura obravnava nastavitev ravnin in izbiro pulznih zaporedij ter protokolov pri MR preiskavi srca. Poleg tega smo želeli opisati izvedbo preiskave, ki je bila izvedena na Centru za klinično fiziologijo ter jo primerjati s pregledano literaturo. Metode dela: V teoretičnem delu smo uporabili metodo deskripcije pri opisovanju pojmov in metodo kompilacije pri uporabi izpiskov, navedb in citatov drugih avtorjev. Izbrali smo predvsem knjižna dela v angleškem jeziku. V praktičnem delu smo uporabili metodo opisa kliničnega primera predhodno izvedene MR preiskave srca. Slikanje so opravili na Centru za klinično fiziologijo. Uporabili so MR tomograf Philips Achieva 3.0 T TX, tuljavo Sense XL Torso Coil 16 Channel ter integrirane Philipsove priprave za proženje. Na podlagi pridobljenih podatkov smo primerjali različne načine nastavitve osnovnih ravnin in izbore pulznih zaporedij. Rezultati: V literaturi smo se osredinili na tri opise nastavitvev ravnin za MR slikanje srca. Postopki se razlikujejo po zaporedju in številu posnetkov. Ločeno smo opisali pulzna zaporedja za slikanje svetle krvi, temne krvi in za zajemanje kino posnetkov. V samostojnem poglavju smo povzeli še posebne tehnike, ki se uporabljajo pri MR slikanju srca. Opisujemo različne vrste paralelnega slikanja in delnega Furierjevega zajemanja ter diahrono UNFOLD tehniko. Primer slikanja srca, ki smo ga opisali, je vseboval strukturne in funkcionalne posnetke v osnovnih ravninah. Proženje je bilo vezano na EKG in dihalno blokado. Razprava in zaključek: Literatura ni soglasna pri načinih nastavitve osnovnih ravnin, točne izbire pulznih zaporedij, njihovih parametrov ali načina proženja. Pregledani viri so sklepni pri geometrijskih značilnosti osnovnih ravnin in kontrastnih značilnosti pulznih zaporedij funkcionalnih ter strukturnih posnetkov srca. Protokol opisanega primera je potrebno še optimizirati.Introduction: Cardiac illness is a significant cause of morbidity and mortality in the developed world. Cardiac imaging plays a key role in early heart disease detection and characterization. Cardiac magnetic resonance imaging (MRI) is experiencing rapid evolution. Purpose: We intended to examine how the available literature discusses slice orientation, pulse sequence selection and protocol design in cardiac MRI. Furthermore, we wanted to describe the execution of a cardiac MRI examination at the Center for Clinical Physiology and compare it with the reviewed literature. Methods: In the theoretical part we used a descriptive method to explain the concepts and method of compilation for the use of extracts, statements and quotations from other authors. We used books in English. In the practical part, we used the descriptive method to describe the clinical case of a previously performed the magnetic resonance imaging of the heart. The exam was done at the Center for Clinical Physiology. We used the MR tomograph Philips Achieva 3.0 T TX, the Sense XL Torso Coil 16 Channel coil and integrated Philips trigger devices. On the basis of the obtained data and images, we compared different ways of setting the basic planes and the selection of pulse sequences. Results: We focused on three slice orientation protocols in the literature. These differed in the sequencing and number of acquisitions. We described bright blood, black blood and cine pulse sequences separately. We also summarise advanced techniques common in cardiac MR imaging. Parallel imaging, partial Furier acquisition and the UNFOLD method are described. The protocol executed at our facility included structural and functional sequences. EKG and respiration based gating was employed. Discussion and conclusion: The reviewed sources do not provide consensus regarding the procedure by which the basic imaging planes can be set, the specific pulse sequences to be selected, their parameters or the precise method of gating. There is, however, consensus regarding the final orientation of the basic planes as well as the contrast attributes needed in structural and functional images. The procedure we described still requires optimization