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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Vrednost pozitronske emisione tomografije - kompjuterizovane tomografije u inicijalnom određivanju stadijuma kolorektalnog karcinoma / Importance of positron emission tomography-computed tomography examination in initial colorectal cancer staging

Ivanov Olivera 05 November 2014 (has links)
<p>Kolorektalni karcinom je treća po redu maligna bolest po broju novoobolelih u svetskoj populaciji, posle karcinoma pluća i dojke. Petogodi&scaron;nje preživljavanje od kolorektalnog karcinoma u SAD-u je 59-66%, u zemljama Zapadne Evrope oko 60% a u Autonomnoj Pokrajuni Vojvodini 27%. U razvijenim zemljama se sprovode skrining programi koji omogućavaju rano otkrivanje malignih bolesti, međutim, u Srbiji takav program ne postoji. Stoga je potrebno iznaći nove načine u inicijalnom menadžmentu obolelih od ove bolesti, koji će indirektno povećati njihovo preživljavanje. Jedan od načina je primena &scaron;to savremenijih dijagnostičkih metoda koji će precizno definisati stadijum. PET-CT je imidžing metoda koja poslednjih godina zauzima značajno mesto u određivanju stadijuma malignih bolesti i dijagnostikovanju recidiva. Fuzionisanjem skenova PET-a i CT-a dobija se PET-CT slika koja prikazuje funkcionalno stanje pojedinih tkiva i organa (PET) sa anatomskim detaljima (CT). Cilj istraživanja je bio da se utvrdi vrednost PET-CT pregleda u određivanju stadijuma KRK kao i u planiranju radioterapije. Nakon pregleda, pacijenti su ili operisani ili podvrgnuti planiranju radioterapije. Kod operisanih pacijenata poredilo se određivanje stadijuma PET-CT pregledom i PH metodom.Utvrđeno je da kod određivanja T stadijuma ne postoji statistički značajna razlika u<br />određivanju stadijuma KRK između navedene dve metode odnosno da je senzitivnost za ovaj parameter 90,7%. PET-CT pregled ima nisku senzitivnost za procenjivanje proboja mezorektalne fascije koja iznosi 77,3%. U određivanju N stadijuma, PET-CT pregled se pokazao kao visokosenzitivan (85,8%). Od 4 pacijenta kod kojih su dijagnostikovane metastatske lezije jetre, kod svih su one i patohistolo&scaron;ki verifikovane &scaron;to predstavlja 100% tačnost. Kod poređenja planiranja radioterapije na osnovu PET-CT pregleda i samo CT simulatora, za GTV meru, ova vrednost je u grupi pacijenata kod kojih je planiranje vr&scaron;eno nakon fuzije CT i PET-CT slike bila za 65,5% manja u odnosu na retrospektivnu grupu kod koje je planiranje vr&scaron;eno samo na osnovu CT pregleda. Za CTV volumene, dobijena je statistički značajna razlika u poređenju prospektivne i retrospektivne grupe u smislu manjih volumena u prvoj grupi. Kod poređenja PTV volumena, nije dobijena statistički značajna razlika. Takođe, kada se poredila doza zračenja koju su primili organi od rizika (m.be&scaron;ika i glave femura), dobijeno je da su statistički značajno manje doze primili navedeni organi u prospektivnoj grupi, kada se planirnaje vr&scaron;ilo pomoću PET-CT slajsova. Na&scaron;i rezultati pokazuju da bi kod dve trećine pacijenata do&scaron;lo do promene u terapijskom modalitetu kada bi svaki pacijent inicijalno, pre bilo kakve terapije bio podvrgnut PET-CT pregledu. Istraživanjem je potvrđena hipoteza da primena PET-CT pregleda ima značaja u inicijalnom određivanju stadijuma KRK kod većine pacijenata (96,3% pacijenata). Takođe je potvrđeno da ova metoda ima veliku vrednost u planiranju radioterapije smanjujući ozračivanje zdravih tkiva i pobolj&scaron;avajući kvalitet terapije tumora.</p> / <p>Colorectal carcinoma is third malignant disease by the frequency of appearance worldwide, following lung and breast cancer. Five-year survival from colorectal cancer is 59-66% in the USA, 60% in Western Europe and 27% in Region of Vojvodina. In developed countries, screening programs that provide early detection of the malignancies are in use, but in Serbia such program doesn&rsquo;t exsist.Therefore, upgrading of the initial colorectal cancer management is necessary in order of survival benefit. Accurate preoperative staging is essential in determining the optimal therapeutic procedures and planning for individual patients. Advances in imaging technology have raised interest in the potential role of PET-CT examination for staging of colorectal cancer. By PET and CT scan fusion, functional and anatomical informations are both provided. Aim of this study was to evaluate PET-CT examination in colorectal cancer staging and radiotherapy planning. After examination, patients underwent surgery or radiotherapy. In operated group, histopathological examination was the reference standard. Analysing the use of PET-CT in T stage evaluation our results showed high sensitivity of 90,7%. PET-CT examination has low sensitivity in analyzing mesorectal fascia involvement (77,3%). It was showed that PET-CT is very sensitive in N staging (85,8%). Four of the patients had liver metastases on PET-CT, and all of them were histopathologicaly confirmed, so the accuracy of M staging was 100%. In radiotherapy planning comparison, for GTV measure, we concluded that PET-CT planning provide 65,5% less tumor irradiated volume compared with CT planning. For CTV volumes, our results show that there is statistically significant difference between prospective and retrospective group with smaller volumes in the first group. In PTV volume comparison, the difference wasn&rsquo;t statistically significant. Also, when we compared doses that received organs of risk (bladder, femoral heads), we got statistically significant differences which means that less doses patients received in prospective group where planning was performed with PET-CT scans. Our results show that after initial PET-CT examination therapy modality changes in two thirds of the patients. This study confirmed the hypothesis that PET-CT has an impact on initial colorectal cancer staging in most of the patients (96,3% of the patients). Also, this examination has a great value in radiotherapy planning because it decriases radiation of the healty tissue and provides better quality of tumor therapy.</p>
2

Značaj hibridnog dijagnostičkog imidžinga u preoperativnoj evaluaciji karcinoma grlića materice / The importance of hybrid diagnostic imaging in thepreoperative evaluation of cervical cancer

Malenković Goran 11 March 2016 (has links)
<p>Uprkos postojanju dijagnostičkih procedura za ranu dijagnostiku, sprovođenju preventivnog skrining programa, te dugom preinvazivnom periodu u kojem je moguće izvr&scaron;iti detekciju, karcinom grlića materice i dalje predstavlja jedan od vodećih zdravstvenih problema, imajući u vidu činjenicu da je uzrok obolevanja i umiranja velikog broja žena &scaron;irom sveta. Oko 85% karcinoma grlića materice dijagnostikuje se u zemljama u razvoju, čineći čak 15% svih malignih tumora kod žena, dok u razvijenim zemljama ovaj procenat iznosi 3,6% novootkrivenih karcinoma. Prema podacima Registra za rak Vojvodine, u AP Vojvodini u 2011. godini, od ukupnog broja novoregistrovanih malignih bolesti kod žena, karcinom grlića materice se nalazio na četvrtom mestu, sa procentualnim uče&scaron;ćem od 6,66%, dok je najveći broj novoobolelih slučajeva u starosnoj grupi 45&ndash;49 godina, pokazujući trend pomeranja prema mladjim starosnim grupama. Primena novih, savremenih dijagnostičkih metoda u inicijalnom zbrinjavanju obolelih od karcinoma grlića materice može doprineti pravilnijem tretmanu bolesti, utičući na tok bolesti, ishod i preživljavanje. PET/CT je hibridna imidžing metoda koja poslednjih godina zauzima značajno<br />mesto u određivanju stadijuma malignih bolesti i dijagnostikovanju recidiva, a kojom se stiče uvid u metaboličko/funkcionalni status ispitivanih tkiva i organa, superponiran na morfoanatomsku CT sliku. Kako je za cilj istraživanja postavljeno utvrđivanje značaja PET/CT pregleda u preoperativnoj evaluaciji karcinoma grlića materice, ispitanice koje su ispunjavale kriterijume za uključivanje u istraživanje su operisane nakon načinjenog PET/CT pregleda, a zatim su poređeni parametri dobijeni kliničkim pregledom, PET/CT pregledom, intraoperativnim pregledom i patohistolo&scaron;kim pregledom. Rezultati načinjenog istraživanja ukazuju da hibridni PET/CT imidžing ne demonstrira prednost u odnosu na dosada&scaron;nje preporuke vezane za preoperativnu dijagnostičku evaluciju ispitanica sa ranim stadijumom karcinoma grlića materice, naročito u detekciji postojanja primarnog tumora dimenzija manjih od 7mm i u detekciji prisustva mikrometastaza u lokoregionalnim limfnim čvorovima zbog jo&scaron; uvek ograničene prostorne rezolucije. PET/CT je pokazao izuzetno visoku specifičnost u utvrđivanju nepostojanja primarnog tumora i visoku komplementarnost sa patohistolo&scaron;kim nalazom. Uočeno je da PET/CT demonstrira statistički značajniju tačnost u proceni stepena pro&scaron;irenosti osnovne bolesti u odnosu na kliničko i intraoperativno utvrđivanje stepena pro&scaron;irenosti osnovne bolesti. Standardizovana vrednost preuzimanja radiofarmaka (SUV) zavisna od histolo&scaron;kog tipa karcinoma grlića materice, demonstrirajući najvi&scaron;e vrednosti u planocelularnom karcinomu i u lo&scaron;e diferentovanom tip G3 karcinomu grlića materice, pozitivno korelirajući sa promerom tumora. Pokazujući značajan potencijal u detekciji primarnog karcinoma grlića materice, kao i u detekciji metastaza u lokoregionalnim limfnim čvorovima, PET/CT nalazi svoje mesto u dijagnostičkoj obradi bolesnica sa karcinomom grlića materice.</p> / <p>Despite the existence of the diagnostic procedures for early diagnosis, implementing preventive screening programs and long preinvasive period in which it is possible to perform detection, cervical cancer remains one of the leading health problems, bearing in mind the fact that it is the cause of morbidity and mortality of a large number of women throughout the world. About 85% cases of cervical cancer are diagnosed in underdeveloped and developing countries. In economically underdeveloped countries, cervical cancer accounts for 15% of all malignant tumors in women, whereas in developed countries it is 3.6% of new cancers. According to data from the Cancer Registry of Vojvodina, in AP Vojvodina, in 2011, of the total number of newly registered malignant diseases in women, cervical cancer was in fourth place, with a percentage share of 6.66% , the largest number of new cases is in the 45-49 years age group, with the shifting the peak in the incidence of cervical cancer towards younger age groups. Applying of new diagnostic methods in the initial management of patients with cervical cancer, indirectly affect the course of the disease, its treatment, and survival. PET-CT hybrid imaging method in recent years occupies an important place in the staging of malignant disease and the diagnosis of recurrence, showing the functional state of certain tissues and organs (PET) with anatomical details (CT). As the aim of this study was to assess the importance of PET / CT scans in the preoperative evaluation of cervical cancer, the women who met the criteria were included in the study, and were operated after having PET / CT scans done, after which the parameters of the results of clinical examination, PET / CT examination, intraoperative examination and histopathological examination, were compared. It was observed that the hybrid PET / CT imaging does not demonstrate the advantage compared to the previous recommendations related to the preoperative diagnostic evaluation of patients with early-stage cervical cancer, especially in the detection of primary tumor measuring less than 7mm and the detection of the presence of micrometastases in the locoregional lymph nodes, due to the still limited spatial resolution. PET / CT showed extremely high specificity in determining the absence of primary tumor and high complementarity with histopathological findings. The study showed that PET / CT demonstrates statistically more significant accuracy in the assessment of the extent of the underlying disease, compared with the clinical and intraoperative determination of the extent of the underlying disease. It has been shown that the standardized uptake value of radiopharmaceuticals (SUV) depends on the histological type of cervical cancer, demonstrating the highest values in squamous-cell carcinoma and then in poorly differentiated G3 carcinoma of the cervix, positively correlating with the diameter of the tumor. Demonstrating significant potential in the detection of primary cervical cancer, as well as in the detection of metastases in locoregional lymph nodes, PET / CT has its place in diagnostic treatment of patients with cervical cancer.</p>
3

Kognityvinių funkcijų sutrikimai sergant išsėtine skleroze, jų ryšys su demografiniais klinikiniais rodikliais ir pakitimais magnetinio rezonanso tomografijos tyrime / Cognitive dysfunction in multiple sclerosis, its relationship with demographic and clinical factors and changes in magnetic resonance imaging

Kizlaitienė, Rasa 30 November 2012 (has links)
Išsėtinė sklerozė (IS) – demielinizuojanti uždegiminė neurologinė liga, kylanti dažniausiai jauniems žmonėms. Svarbi ne tik IS fizinė negalia, bet ne mažiau svarbi ir kognityvinė negalia, kuri reiškiasi kognityvinių funkcijų sutrikimu (KFS). Nors KFS simptomai gali būti labai įvairūs, dažniausiai nukenčia išmokimas, atmintis, dėmesys, informacijos apdorojimo greitis, vizualiniai konstrukciniai gebėjimai ir valdomosios funkcijos. Darbo tikslas buvo įvertinti demografinių ir klinikinių ligos rodiklių bei pakitimų magnetinio rezonanso tomografijos tyrime įtaką išsėtine skleroze sergančių ligonių kognityvinėms funkcijoms (KF). Ištyrėme 120 IS sergančių ligonių ir 40 sveikų asmenų. Įvertinome fizinę negalią, subjektyvius nusiskundimus atmintimi ir nuovargiu, objektyvų nuovargį, depresiją ir nerimą. Kognityvinių funkcijų vertinimui buvo atlikta vienuolikos kognityvinių testų rinkinys. Galvos smegenų magnetinio rezonanso tomografijos (MRT) tyrimuose įvertintas demielinizacijos židinių skaičius, tiesiniai atrofijos matmenys ir jų santykiai. Sergančių IS KF buvo blogesnės nei sveikų asmenų, priklausė nuo ligos eigos, objektyvi depresija blogino KF rezultatus. IS subjektyvūs skundai atmintimi ir nuovargiu neturėjo ryšio su KF. IS sergančiųjų KFS ir galvos smegenų atrofija buvo labiau išreikšti sergant antrinės progresuojančios (AP) negu recidyvuojančios remituojančios (RR) eigos IS. MRT židinių skaičiaus įtaka KF testų rezultatams labiau atsispindėjo IS pradžioje. Sergančiuosius RR ir... [toliau žr. visą tekstą] / Multiple sclerosis (MS) is a chronic demyelinating inflammatory neurological disease in young adults. Cognitive dysfunction (CD) contributes significantly to patient’s disability status. Although almost all kind of CD can be observed in MS, the typical profile is the impairment of information processing speed, memory, attention and often executive skills. The aim of the study was to investigate the influence of different demographic and clinical markers of the disease and changes in MRI tomography on cognitive functions in MS patients. The study involved 120 patients with MS and 40 healthy controls. Neurological examination, complaints of memory and fatigue, objective depression, anxiety and objective fatigue were evaluated. Cognitive functions (CF) were tested using battery of 11 cognitive tests. Brain MRI was performed to evaluate focal demyelinised lesions and to calculate regional linear markers of brain atrophy. The impairment of CF was much more expressed in MS patients as compared to controls. CF were negatively affected by objective depression and disease course. Subjective memory complaints and subjective fatigue in MS patients did not correlate with CF however they did correlate with objective fatigue. Self reported memory impairment worsened with the progression of disease. CD and brain atrophy reflected by MRI linear parameters were more expressed in secondary progressive (SP) MS as compared to relapsing remitting (RR) MS. Number of demyelinated lesions were... [to full text]
4

Kognityvinių funkcijų sutrikimai sergant Išsėtine skleroze, jų ryšys su demografiniais klinikiniais rodikliais ir pakitimais Magnetinio rezonanso tomografijos tyrime / Cognitive dysfunction in Multiple sclerosis, its relationship with demographic and clinical factors and changes in Magnetic resonance imaging

Kizlaitienė, Rasa 30 November 2012 (has links)
Išsėtinė sklerozė (IS) – demielinizuojanti uždegiminė neurologinė liga, kylanti dažniausiai jauniems žmonėms. Svarbi ne tik IS fizinė negalia, bet ne mažiau svarbi ir kognityvinė negalia, kuri reiškiasi kognityvinių funkcijų sutrikimu (KFS). Nors KFS simptomai gali būti labai įvairūs, dažniausiai nukenčia išmokimas, atmintis, dėmesys, informacijos apdorojimo greitis, vizualiniai konstrukciniai gebėjimai ir valdomosios funkcijos. Darbo tikslas buvo įvertinti demografinių ir klinikinių ligos rodiklių bei pakitimų magnetinio rezonanso tomografijos tyrime įtaką išsėtine skleroze sergančių ligonių kognityvinėms funkcijoms (KF). Ištyrėme 120 IS sergančių ligonių ir 40 sveikų asmenų. Įvertinome fizinę negalią, subjektyvius nusiskundimus atmintimi ir nuovargiu, objektyvų nuovargį, depresiją ir nerimą. Kognityvinių funkcijų vertinimui buvo atlikta vienuolikos kognityvinių testų rinkinys. Galvos smegenų magnetinio rezonanso tomografijos (MRT) tyrimuose įvertintas demielinizacijos židinių skaičius, tiesiniai atrofijos matmenys ir jų santykiai. Sergančių IS KF buvo blogesnės nei sveikų asmenų, priklausė nuo ligos eigos, objektyvi depresija blogino KF rezultatus. IS subjektyvūs skundai atmintimi ir nuovargiu neturėjo ryšio su KF. IS sergančiųjų KFS ir galvos smegenų atrofija buvo labiau išreikšti sergant antrinės progresuojančios (AP) negu recidyvuojančios remituojančios (RR) eigos IS. MRT židinių skaičiaus įtaka KF testų rezultatams labiau atsispindėjo IS pradžioje. Sergančiuosius RR ir... [toliau žr. visą tekstą] / Multiple sclerosis (MS) is a chronic demyelinating inflammatory neurological disease in young adults. Cognitive dysfunction (CD) contributes significantly to patient’s disability status. Although almost all kind of CD can be observed in MS, the typical profile is the impairment of information processing speed, memory, attention and often executive skills. The aim of the study was to investigate the influence of different demographic and clinical markers of the disease and changes in MRI tomography on cognitive functions in MS patients. The study involved 120 patients with MS and 40 healthy controls. Neurological examination, complaints of memory and fatigue, objective depression, anxiety and objective fatigue were evaluated. Cognitive functions (CF) were tested using battery of 11 cognitive tests. Brain MRI was performed to evaluate focal demyelinised lesions and to calculate regional linear markers of brain atrophy. The impairment of CF was much more expressed in MS patients as compared to controls. CF were negatively affected by objective depression and disease course. Subjective memory complaints and subjective fatigue in MS patients did not correlate with CF however they did correlate with objective fatigue. Self reported memory impairment worsened with the progression of disease. CD and brain atrophy reflected by MRI linear parameters were more expressed in secondary progressive (SP) MS as compared to relapsing remitting (RR) MS. Number of demyelinated lesions were... [to full text]
5

Primena PET/CT pregleda u planiranju radiološke terapije kod pacijenata obolelih od Hočkinovog limfoma / The use of PET/CT in radiotherapy planning in patients with Hodgkin's lymphoma

Mitrić Ašković Milana 19 July 2016 (has links)
<p>Studija je imala za cilj da pokaže značaj primene PET/CT pregleda u planiranju radiolo&scaron;ke terapije kod pacijenata obolelih od Hočkinovog linfoma. U Vojvodini je 2009. godine prema podacima Registra za maligne neoplazme Vojvodine incidence za Hočkinov limfom iznosila 2,7 na 100 000 dok je mortalitet bio 1,1 na 100 000 stanovnika. Na osnovu dostupnih podataka Registra za maligne neoplazme Vojvodine beleži se porast incidence u protekloj deceniji. Procenat obolelih u Vojvodini u korelaciji je sa podacima koje navodi i Međunarodna agencija za istraživanje raka iz Liona (IARC). U Evropi i u Sjedinjenim Američkim Državama postoji bimodularna kriva incidence po starosti koja pokazuje maksimalne vrednosti u period između 20 i 30 godina i nakon 55. godine. S obzirom da od Hočkinovog limfoma dominantnije obolevaju mlađe osobe a da bolest ima dobru prognozu neophodno je iznaći nove načine za inicijalno određivanje stadijuma bolesti, kao i metode koje mogu da unaprede kvalitet lečenja. Jedan od načina je primena &scaron;to savremenijih dijagnostičkih metoda. PET-CT je imidžing metoda koja poslednjih godina zauzima značajno mesto u određivanju stadijuma malignih bolesti kao i u proceni odgovora na primenjenu terapiju. Fuzionisanjem skenova PET-a i CT-a dobija se PET-CT slika koja prikazuje funkcionalno stanje pojedinih tkiva i organa (PET) sa anatomskim detaljima (CT). Cilj istraživanja je bio da se utvrdi prednost PET-CT pregleda u planiranju radioterapije kod pacijenata sa supradijafragmalnom lokalizacijom bolesti. Nakon postavljanja dijagnoze Hočkinovog limfoma kod pacijenata je urađen PET-CT i planiranje radiolo&scaron;ke terapije. Zračna terapija je planirana na osnovu nalaza PET-CT-a i njegovom fuzijom sa CT-om za planiranje radiolo&scaron;kog lečenja. Dobijeni planovi su poređeni sa onim koji su rađeni standardnom 3D konformalnom tehnikom bez fuzije. Poređeni su klinički volumeni (CTV) i planirani volumen (PTV) kao i razlike u njihovoj obuhvaćenosti preskribovanom dozom. Pokazano je da postoji statistički značajna razlika u ciljnim volumenima kao i u njihovoj obuhvaćenosti. Posmatrani su takođe i rizični organi- srce, pluća, dojke, &scaron;titasta žlezda, kičmena moždina i doze koje oni prime. Dokazano je da su sa statističkom značajno&scaron;ću dozna opterećenja na navedene rizične organe manja kada se planiranje vr&scaron;i na osnovu fuzije sa PET-CT-om, te se na osnovu toga može reći da će i očekivane manifestacije kasne toksičnosti biti manje. Istraživanjem je potvrđena hipoteza da PET/CT ima veliku prednost u planiranju radioterapije jer smanjuje zapremine ciljnih volumena i doprinosi pobolj&scaron;anju kvaliteta radiolo&scaron;kog lečenja.</p> / <p>This study aimed to prove that the use of PET/CT in radiotherapy planning makes a material change in the course of the treatment of the patients with Hodgkin&#39;s lymphoma. According to the data from the Registry of malignant neoplasms in Vojvodina, incidence of Hodgkin&#39;s lymphoma in Vojvodina in 2009 was 2.7 per 100 000, while the mortality rate was 1.1 per 100 000 inhabitants. Based on the available data, the said Register recorded an increase in the incidence over the past decade. The percentage of patients who were registered in Vojvodina is in correlation with the data cited by the International Agency for Research on Cancer in Lyon (IARC).In Europe and in the United States the disease has a bi-modular distribution distribution with the highest frequency rate in persons ageing from 20-30 years and people older than 55 years. Due to the fact that the dominant Hodgkin&#39;s lymphoma affects young people and having in mind the good prognosis of the disease, it is necessary to find a new modality for the initial staging of disease and methods which can improve the quality of treatment. PET/CT is the imaging method which has in recent years had an important role in the staging of malignancies, as well in the evaluation of response to therapy. PET/CT image is obtained by fusing PET scans with CT and it show functional status of certain tissues and organs (PET) with anatomical details (CT).The object of this study was to show that PET/CT examinations are preferred imaging method in radiotherapy planning in patients with localized disease above the diaphragm. After they had been diagnosed with HL, patients underwent PET/CT scan which was later used for delineation in radiotherapy planning. In this study, radiation therapy was planned on the basis of the findings of PET /CT and its fusion with CT for planning radiological treatment. The resulting plans were compared with those made using standard 3D conformal technique without fusion. Clinical volume (CTV) and the planned volume (PTV) and the differences in their coverage with the prescription dose in both plans were also compared. The study has shown a statistically significant difference in the target volume and their coverage. In addition, the dose which receive organs at risk was also examined. It has been shown that organs at risk were exposed to lower doses when using PET/CT fusion in radiotherapy planning and consequently, less incidence of late toxicity is to be expected. The study confirmed the hypothesis that PET /CT has a great advantage in the planning of radiotherapy because it reduces the volume of the target volume and improves the quality of radiation treatment.</p>
6

Visiška kairiosios Hiso pluošto kojytės blokada ir vainikinių arterijų angiografijos daugiapjūviu kompiuteriniu tomografu tyrimo vertė / Performance of the multislice computed tomography angiography of the coronary arteries in patients with complete left bundle branch block

Jankauskas, Antanas 22 April 2010 (has links)
Vainikinių arterijų tyrimas daugiapjūviu kompiuteriniu tomografu (DKT) į klinikinę praktiką įdiegtas nesenai. Tai neinvazyvus tyrimo metodas, kurį galima atlikti ir ambulatoriniams pacientams. Tačiau greta savo privulumų, jis turi ir trūkumų – dėl nuolatinio vainikinių arterijų judėjimo širdies ciklo metu gali atsirasti liekamųjų judesio artefaktų atkuriant vaizdus. Jų tikimybė priklauso ne tik nuo aparato, kuriuo atliekamas tyrimas, techninių charakteristikų, bet ir nuo širdies veiklos ypatumų. Yra atlikta nemažai tyrimų, įvertinančių vainikinių arterijų vaizdų kokybės priklausomybę nuo širdies susitraukimų dažnio, jo variabilumo, kitų faktorių. Kairiosios Hiso pluošto kojytės blokados, sąlygojančios nesinchronišką skilvelių susitraukimą ir atsipalaidavimą, įtaka vaizdų kokybei tyrinėta mažai. Šiame tyrime buvo palyginta vaizdų kokybė tarp pacientų, kuriems nustatyta visiška kairiosios Hiso pluošto kojytės blokada ir nėra laidžiosios sistemos sutrikimų, grupių. Analizuota vainikinių arterijų įvertinimo visuose širdies ciklo rekonstrukciniuose intervaluose įtaka vaizdų kokybės vidurkiui. Nustatyta, kokia yra DKT tyrimo diagnostinė vertė identifikuojant hemodinamiškai reikšmingas vainikinių arterijų stenozes. Kadangi DKT tyrimas susijęs su jonizuojančia spinduliuote, įvertinti rentgeno vamzdžio srovės stiprumo moduliavimo ypatumai. Taip pat nustatyta širdies susitraukimų dažnio, jo variabilumo įtaka vaizdų kokybei, esant visiškai kairiosios Hiso pluošto kojytės blokadai. / Multislice computed tomography (MSCT) coronary angiography is one of the latest usage area of the computed tomography technology. It s a non-invasive diagnostic tool, wich can be performed in ambulant patients. MSCT coronary angiography beside it's advantages has some drawbacks. The main drawbacks are lower spatial resolution and residual motion artifacts in MSCT images. Therefore quality of coronary images and diagnostic value of MSCT angiography differs, depending on patient's clinical characteristics, especially on heart contraction features during scanning. Asynchronic contraction and relaxation of the right and left ventricles, caused of bundle branch block can also influence image quality of MSCT coronary angiography. To date, there are only few studies, conducted to analyse diagnostic performance of MSCT coronary angiography in patients with left bundle branch block. Although influence of heart rate, heart rate variability and the other factors (for example, age, sex, body mass index) on MSCT image quality are quite well investigated. Thus, the present study were designed to investigate the influence of complete left bundle branch block on image quality of MSCT coronary angiography more detail in comparison with control patients group without electrical conduction disturbances, reveal the diagnostic value of MSCT angiography to identify hemodinamicaly significant coronary stenosis.
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Lietuvoje besiveisiančių usūrinių šunų (Nyctereutes procyonoides) ir rudųjų lapių (Vulpes vulpes) skeleto morfologinė analizė / Skeletal morphological analysis of raccoon dogs (Nyctereutes procyonoides) and red foxes (Vulpes vulpes) in Lithuania

Jurgelėnas, Eugenijus 11 May 2010 (has links)
Darbo tikslas: atlikti palyginamąją rudųjų lapių ir usūrinių šunų kaukolių, ilgųjų ir plokščiųjų galūnių kaulų osteologinę ir osteometrinę analizę. Darbo uždaviniai: 1. Išmatuoti ir palyginti usūrinių šunų ir rudųjų lapių patinų ir patelių kaukoles su apatiniais žandikauliais, krūminius dantis, plokščiuosius galūnių kaulus – mentę ir dubens kaulus ir ilguosius galūnių kaulus – petikaulį, dilbio kaulus, šlaunikaulį ir blauzdos kaulus. 2. Naudojantis gautais matmenimis atlikti tarprūšinį usūrinių šunų ir rudųjų lapių kaukolių su apatiniais žandikauliais, krūminių dantų, plokščiųjų galūnių kaulų – mentės ir dubens kaulų ir ilgųjų galūnių kaulų – petikaulio, dilbio kaulų, šlaunikaulio ir blauzdos kaulų palyginimą. 3. Apskaičiuoti kaukolių ir nurodytų ilgųjų galūnių kaulų – petikaulio, stipinkaulio, šlaunikaulio ir blauzdikaulio indeksus ir atlikti šių indeksų palyginimą tarp lyčių ir tarp tirtų gyvūnų rūšių. 4. Atlikti tarprūšinį kaukolių su apatiniais žandikauliais, plokščiųjų galūnių kaulų – mentės ir dubens kaulų, ilgųjų galūnių kaulų – petikaulio, dilbio kaulų, šlaunikaulio ir blauzdos kaulų morfologinį tyrimą palyginamosios anatomijos metodu. 5. Nustatyti tarprūšinius rudųjų lapių ir usūrinių šunų kaukolių vidinių struktūrų ir kaktikaulio ančių morfologinius ypatumus naudojant kompiuterinės tomografijos metodą. Pirmą kartą Lietuvoje atlikta palyginamoji usūrinių šunų ir rudųjų lapių kaukolių ir galūnių kaulų morfologinė analizė. Laukinės faunos osteologiniuose tyrimuose... [toliau žr. visą tekstą] / The aim of the present study is: to carry out a comparative osteological and osteometric analysis of skulls and long and flat bones of extremities of red foxes and raccoon dogs. The tasks include: 1. Measuring and comparison of the bones of male and female red foxes and raccoon dogs: skulls with jawbones, molars, the flat bones of extremities – scapula and pelvic bones – and the long bones of extremities – humerus, forearm, femur and crural bone. 2. Comparison of the bones of raccoon dogs and red foxes based on the obtained osteometric data about: skulls with jawbones, molars, the flat bones of extremities – scapula and pelvic bones – and the long bones of extremities – humerus, forearm bones, femur and crural bone. 3. Calculation of the indices of skulls and the indicated long bones of extremities – humerus, radius, femur and tibia – and comparison of these indices in the studied animals of different gender and species. 4. Morphological analysis of the bones – skulls with jawbones, the flat bones of extremities (scapula and pelvic bones) and the long bones of extremities (humerus, forearm, femur and crural bone) – of the studied species of animals by the method of comparative anatomy. 5. Determining the morphological features of the bones – internal structure of the skulls and frontal sinuses – of the studies species of animals (red foxes and raccoon dogs) by the method of computer tomography. The present work is a first attempt of comparative morphological analysis of the... [to full text]
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Magnetinio rezonanso tomografijos reikšmė vertinant gimdos kaklelio vėžio išplitimą ir chemospindulinio gydymo efektyvumą / The Significance of Magnetic Resonance Imaging for the Assessment of the Outspread of Cervical Cancer and of the Efficiency of Chemoradiation Therapy

Atstupėnaitė, Vaida 22 September 2011 (has links)
Magnetinio rezonanso tomografija (MRT) yra optimalus diagnostikos metodas vertinant gimdos kaklelio vėžio išplitimą. Pasaulyje pastaraisiais metais atlikta nedaug mokslinių tyrimų, kuriuose vertinamas gimdos kaklelio vėžys difuzinės MRT metodu. Daugumoje jų dalyvavo nedidelis tiriamųjų skaičius. Šis klinikinis tyrimas yra pirmasis Lietuvoje, kuriuo vertinamas gimdos kaklelio vėžys minėtu metodu, todėl jis turi nemažą mokslinę vertę optimizuojant MRT panaudojimo galimybes gimdos kaklelio vėžio diagnostikoje. Darbo tikslas – nustatyti konvencinės ir difuzinės MRT reikšmę vertinant gimdos kaklelio vėžio išplitimą ir chemospindulinio gydymo efektyvumą. Darbo uždaviniai: 1. Įvertinti konvencinės MRT metodu nustatytų gimdos kaklelio vėžio prognozės veiksnių tarpusavio ryšį su klinikinio ir histologinio tyrimų duomenimis. 2. Apskaičiuoti konvencinės MRT diagnostinės vertės parametrus gimdos kaklelio piktybiniam augliui ir liekamajam po chemospindulinio gydymo naviko audiniui. 3. Palyginti tariamojo difuzijos koeficiento (ADC) skaitinės reikšmės vidurkį sveikame gimdos kaklelyje, vėžio pažeistame ir po chemospindulinio gydymo. Nustatyti gimdos kaklelio vėžiui būdingą ADC skaitinės reikšmės ribą. Įvertinti ADC skaitinės reikšmės tarpusavio ryšį su įvairiais klinikinio ir histologinio tyrimų duomenimis. 4. Apskaičiuoti konvencinės ir difuzinės MRT derinio diagnostinės vertės parametrus gimdos kaklelio piktybiniam augliui ir liekamajam po chemospindulinio gydymo naviko audiniui. / Magnetic resonance imaging (MRI) is the optimal method for evaluation of spread of cervical cancer. Only a few diffusion–weighted (DW) MRI studies in the field of cervical cancer have been accomplished around the world. Most of them included a small number of subjects. This is the first clinical study in Lithuania that assesses the cervical cancer by DW–MRI and it has the scientific value in optimizing the use of MRI potential in the evaluation of the diagnostics and treatment efficiency of the mentioned illness. The aim – to identify the significance of conventional and DW–MRI in the assessment of the outspread of cervical cancer and of the efficiency of chemoradiation therapy. The objectives: 1. To assess the interrelationship of prognostic factors of cervical cancer detected by conventional MRI with clinical and histological findings. 2. To calculate the diagnostic value parameters of conventional MRI for the malignant cervical tumor and for the residual tumor tissue after chemoradiation therapy. 3. To compare the mean value of apparent diffusion coefficient (ADC) in a healthy, cancer affected cervix and the cervix after chemoradiation therapy. To identify the value range of ADC typical for cervical cancer. To evaluate the correlation of ADC with the various clinical and histological findings. 4. To calculate the diagnostic value parameters of conventional and DW–MRI combination for the malignant cervical tumor and for the residual tumor tissue after chemoradiation therapy... [to full text]
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Procena doza i optimizacija protokola pri standardnim pregledima višeslojnom kompjuterizovanom tomografijom / Assessment of dosage and optimization of protocol at standard examinations with multislice computerized tomography

Hadnađev Šimonji Darka 21 December 2015 (has links)
<p>Kompjuterizovana tomografija (CT) je jedan od najznačajnijh dijagnostičkih modaliteta, čija upotreba raste iz decenije u deceniju. U ukupnom broju radiolo&scaron;kih pregleda CT je zastupljena sa 5-10%, ali je njen doprinos ukupnoj dozi za populaciju veći od 50%. Osnovni pokazatelji kvaliteta slike i doza, kao i prateći radijacioni rizik zavise od primenjene radiografske tehnike odnosno CT pregleda. U smislu&nbsp; dobre radiolo&scaron;ke prakse i u skladu sa osnovnim principima za&scaron;tite od zračenja, poželjna je primena najniže moguće doze za pacijenta uz održavanje kvaliteta slike i dijagnostičke informacije. Cilj istraživanja jeste definisanje optimalnog protokola pregleda vi&scaron;eslojnom CT za dijagnozu pojedinih regija tela, kao i da se utvrde doze i radijacioni rizik za pacijente pre i nakon optimizacije protokola. Analizom je obuhvaćeno ukupno 437 pacijenata, koji su podeljeni u grupe prema regijama tela koje su snimane: I&ndash;nekontrastni CT glave, II-CT glave sa i.v. kontrastom, III-CT grudnog ko&scaron;a, IV-CT abdomena i karlice i V-CT angio (CT angiografija aortoilijačnog segmenta i donjih ekstremiteta). Studija je izvedena u 2 faze: u I fazi je kori&scaron;ćen standardni protokol za regiju tela koja se snimala, a u II fazi CT pregledi su izvedeni po modifikovanom protokolu (promenom parametra vrednosti mAs), uz minimalne zahteve u pogledu kvaliteta slike.Na osnovu dozimetrijskih&nbsp; pokazatelja procenjena je efektivna doza i radijacioni rizik za pacijente u obe faze. U studiji su kori&scaron;ćene smernice iz Vodiča EUR 16262&nbsp; EN, u kojima su definisani parametri za procenu kvaliteta slike da bi se analizirali različiti anatomski preseci određenih regija tela koji su se snimali. Kvalitet slike za svakog pacijenta je ocenjen pomoću trostepene skale vizualizacije za svaki parametar anatomske regije: 0-detalji su vidljivi, 1-detalji se prikazuju, 2-detalji se jasno prikazuju. Kori&scaron;ćena je subjektivna metoda gde su dva iskusna radiologa vr&scaron;ili interpretaciju slike. Konačna ocena kvaliteta slike svakog pregleda odgovara zbiru svih parametara procenjenih po trostepenoj skali&nbsp; vizualizacije. Zatim je za potrebe izračunavanja veličine FOM (figure of merit) izračunata vrednost indeksa ocene kvaliteta slike (zbir svih&nbsp; ocena parametra/brojem parametara). Vrednost FOM je izračunata kao količnik indeksa ocene kvaliteta slike i efektivne doza po pacijentu. Prosečna vrednost FOM za svaku grupu ispitanika nam je poslužila kao relativni pokazatelj za upoređivanje između neoptimizovane i optimizovane grupe ispitanika za isti tip pregleda. Poređenjem vrednosti efektivne doze u prvoj i drugoj fazi istraživanja kvantifikovano je smanjenje radijacionog opterećenja za pacijente nakon optimizacije protokola. Rezultati su pokazali da je optimalnim izborom protokola u&nbsp;&nbsp; smislu parametara ekspozicije (smanjenjem vrednosti mAs) moguće značajno smanjiti dozu zračenja kod pregleda glave za 7,5%, kod pregleda glave sa angiografijom za 7%, kod pregleda grudnog ko&scaron;a za 40%, kod pregleda abdomena i karlice za 25%. Grupa CT angio&nbsp; nije mogla da bude optimizovana, jer aparat nije prihvatao promenu kvaliteta slike kod zadatih parametara optimizacije. Primenom standardnih protokola postiže se kvalitet slike bolji nego &scaron;to je neophodno, a samim tim i veća doza zračenja nego &scaron;to je potrebno. Optimalnim izborom protokola u smislu parametara ekspozicije moguće je značajno smanjiti dozu zračenja, uz održavanje kvaliteta slike koji je dovoljan za adekvatnu radiolo&scaron;ku interpretaciju slike.</p> / <p>Computed&nbsp; tomography (CT) is one of the most significant diagnostic methods whose application has been increasing from decade to decade.&nbsp; Among the total number of radiological examinations CT accounts for 5-10%, however, its contribution in the whole dosage for the population is greater than 50%. Main indicator of the quality of images and dosages as well as the accompanying irradiation risk depend on applied radiographic technique that is CT examination. In the sense of good radiological practice and in accordance with basic principles of protection from irradiation, the application of the lowest possible dosage for a patient together with preserving the quality of image and diagnostic information are mostly welcomed. The goal of the research is to define the optimum examination protocol by multislice CT in diagnostics of certain body regions as well as to determine dosages and irradiation risk for patients both before and after protocol optimization. The analysis has included 437 patients divided into groups according to body regions which have been scanned: I-unenhanced head CT, II contrast enhanced head CT, III&ndash;chest CT, IV&ndash;abdomen and pelvis CT and&nbsp; V&ndash;angio CT (CT angiography of aortoiliac segment and lower extremities). The study has been conducted in 2 phases: in the first phase standard protocol for the scanned body region has been applied, and in the second phase CT examinations have been carried out according to the modified&nbsp; protocol&nbsp; (by change of parameters of values mAs)&nbsp; with minimum&nbsp; requirements&nbsp; regarding&nbsp; the&nbsp; image&nbsp; quality. On&nbsp; the&nbsp; basis&nbsp; of&nbsp; dosimetric&nbsp; indicators&nbsp; the&nbsp; efficient&nbsp; dosage&nbsp; and&nbsp; irradiation&nbsp; risk&nbsp; for&nbsp; the patients in both phases have been assessed. In the study the guidelines form the Guide EUR&nbsp; 16262&nbsp; EN&nbsp; have&nbsp; been&nbsp; observed&nbsp; where&nbsp; parameters for&nbsp; the&nbsp; assessment&nbsp; of&nbsp; image quality&nbsp; have&nbsp; been&nbsp; defined&nbsp; in&nbsp; order&nbsp; to&nbsp; analyze&nbsp; different&nbsp; anatomic&nbsp; cross sections of certain body&nbsp; regions.&nbsp; Image quality&nbsp; for&nbsp; each&nbsp; patient&nbsp; was&nbsp; assessed&nbsp; by&nbsp; three-level visualization&nbsp; scale&nbsp; for&nbsp; each&nbsp; parameter&nbsp; of&nbsp; anatomic&nbsp; region:&nbsp; 0&ndash;details&nbsp; are&nbsp; visible, 1&ndash;details are&nbsp; presented,&nbsp; 2&ndash;details are clearly&nbsp; presented.&nbsp; A&nbsp; subjective&nbsp; method&nbsp; was applied&nbsp; where&nbsp; two&nbsp; experienced&nbsp; radiologists performed&nbsp; the&nbsp; image interpretation. Final assessment&nbsp; of&nbsp; image quality&nbsp; of&nbsp; every&nbsp; examination corresponds&nbsp; to&nbsp; the&nbsp; sum&nbsp; of&nbsp; all parameters&nbsp; according&nbsp; to&nbsp; three-level&nbsp; visualization&nbsp; scale. Further,&nbsp; for&nbsp; the&nbsp; need&nbsp; of calculation of the size of FOM (figure of merit) the value of the index of assessment of the&nbsp; image&nbsp; quality&nbsp; (sum of all assessments of parameters/number of&nbsp; parameters) has been&nbsp; calculated.&nbsp; The&nbsp; value of&nbsp; FOM&nbsp; has&nbsp; been&nbsp; calculated as a quotient&nbsp; of&nbsp; the&nbsp; image quality assessment index and effective dosage per patient.&nbsp; The average value of FOM for&nbsp; every&nbsp; group&nbsp; of&nbsp; patients&nbsp; has&nbsp; offered us a&nbsp; relative&nbsp; indicator for&nbsp; comparison of&nbsp; non-optimum&nbsp; and optimum group of&nbsp; patients&nbsp; for&nbsp; the&nbsp; same&nbsp; type&nbsp; of&nbsp; examinations.&nbsp; By comparison of values of effective dosage in the first and second phase of the research a decrease in irradiation load for patients after protocol optimization was quantified. The results have&nbsp; shown&nbsp; that&nbsp; by&nbsp; optimum&nbsp; protocol&nbsp; selection&nbsp; in&nbsp; the&nbsp; sense&nbsp; of&nbsp; exposition parameters (by&nbsp; reduction of&nbsp; values of&nbsp; mAs) it is&nbsp; possible to reduce significantly&nbsp; the irradiation dosage at&nbsp; unenhanced head CT examination for 7,5%, at contrast enhanced head CT examination for 7%, at chest CT examination for 40%, at abdomen&nbsp; and pelvis CT examination for 25%. The group CT angio could not be optimized since the device&nbsp; did&nbsp; not&nbsp; accept&nbsp; the&nbsp; change in image quality at set&nbsp; optimization parameters. By application&nbsp; of&nbsp; standard&nbsp; protocols the image quality&nbsp; better&nbsp; than required&nbsp; was&nbsp; achieved and along with this, a higher irradiation dosage occurred than required. By selection of protocol in the sense&nbsp; of&nbsp; exposition parameters it is possible to reduce irradiation dosage significantly along with preserving image quality which is&nbsp; sufficient for adequate radiological image interpretation.</p>
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Hibridni model za segmentaciju snimaka generisanih primenom kompjuterizovane tomografije / A Hybrid Model for Segmentation of Images Generated by X-Ray Computed Tomography

Šokac Mario 18 October 2019 (has links)
<p>Kompjuterizovana tomografija (CT) je u poslednje vreme ušla na velika vrata sa razvojem industrijskih CT sistema, usled njene primene u različitim oblastima, a uveliko ulazi i u polje koodinatne metrologije. Zbog karakterizacije objekata sačinjenih od različitih materijala (najčešće metala i plastike), javljaju se određeni problem u vidu nastanka artefakata kod rezultata dimenzionalnih merenja. Istraživanja koja su sprovedena u ovoj doktorskoj disertaciji se bave problemom redukcije uticaja tih artefakata i segmentacije 2D snimaka. Razvijen je novi model koji je baziran na primeni hibridne metode gde je izvršena kombinacija dve metode za obradu slike, a to su fazi klasterizacija i rast regiona. Aksenat je stavljen na primeni ove hibridne metode radi dobijanja tačnijih rezultata segmentacije, što direktno utiče i na rekonstrukciju dimenzionalno tačnijih 3D modela.</p> / <p>Computed tomography (CT) has recently entered a large door with the development of industrial CT systems, due to its application in many different areas, and it is already entering the field of coordinate metrology. Due to its ability to non-destructively characterize objects made of different materials (typicaly metals and plastics), a certain problem arises in the form of artefacts that are present in the results. Research carried out in this dissertation deals with the problem of reducing the impact of these artefacts and the 2D image segmentation. A new model was developed based on the application of the hybrid method where a combination of two methods for image processing was performed, which are fuzzy clustering and region growing. The accent is emphasized in the application of this hybrid method in order to obtain more accurate segmentation results, which directly affects the reconstruction of dimensionally more accurate 3D models.</p>

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