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Query: "author" (Luka Ležaič) .

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1.
Image reconstruction using small-voxel size improves small lesion detection for positron emission tomography
Sebastijan Rep, Petra Tomše, Luka Jensterle, Leon Jarabek, Katja Zaletel, Luka Ležaič, 2022, original scientific article

Abstract: Background. PET/CT imaging is widely used in oncology and provides both metabolic and anatomic information. Because of the relatively poor spatial resolution of PET, the detection of small lesions is limited. The low spatial resolution introduces the partial-volume effect (PVE) which negatively affects images both qualitatively and quantitatively. The aim of the study was to investigate the effect of small-voxel (2 mm in-line pixel size) vs. standard-voxel (4 mm in-line pixel size) reconstruction on lesion detection and image quality in a range of activity ratios. Materials and methods. The National Electrical Manufacturers Association (NEMA) body phantom and the Micro Hollow-Sphere phantom spheres were filled with a solution of [18F]fluorodeoxyglucose ([18F]FDG) in sphere-to-background ratios of 2:1, 3:1, 4:1 and 8:1. In all images reconstructed with 2 mm and 4 mm in-line pixel size the visual lesion delineation, contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) were evaluated. Results. For smaller (≤ 13 mm) phantom spheres, significantly higher CRC and CNR using small-voxel reconstructions were found, also improving visual lesion delineation. CRC did not differ significantly for larger (≥ 17 mm) spheres using 2 mm and 4 mm in-line pixel size, but CNR was significantly lower; however, lower CNR did not affect visual lesion delineation. Conclusions. Small-voxel reconstruction consistently improves precise small lesion delineation, lesion contrast and image quality.
Keywords: PET/CT, voxel size, contrast recovery coefficient, contrast-to-noise ratio
Published in DiRROS: 24.07.2024; Views: 1; Downloads: 1
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Priporočila za obravnavo bolnikov s pljučnim rakom
Martina Vrankar, Nina Boc, Izidor Kern, Aleš Rozman, Karmen Stanič, Tomaž Štupnik, Mojca Unk, Maja Ebert Moltara, Vesna Zadnik, Katja Adamič, Jernej Benedik, Marko Bitenc, Jasna But-Hadžić, Anton Crnjac, Marina Čakš, Dominik Časar, Eva Ćirić, Tanja Čufer, Ana Demšar, Rok Devjak, Goran Gačevski, Marta Globočnik Kukovica, Kristina Gornik-Kramberger, Maja Ivanetič Pantar, Marija Ivanović, Urška Janžič, Staša Jelerčič, Veronika Kloboves-Prevodnik, Mile Kovačević, Luka Ležaič, Mateja Marc-Malovrh, Katja Mohorčič, Loredana Mrak, Igor Požek, Nina Turnšek, Bogdan Vidmar, Dušanka Vidovič, Gregor Vlačić, Ana Lina Vodušek, Rok Zbačnik, Ivana Žagar, 2023, professional article

Abstract: Leta 2019 so bila objavljena Priporočila za obravnavo bolnikov s pljučnim rakom, ki so v slovenski prostor vnesla prepotrebno poenotenje diagnostike in zdravljenja z namenom izboljšanja preživetja bolnikov s pljučnim rakom. Posodobitev Priporočil tri leta po izidu izvirnika prinaša največ novosti v poglavju o sistemskem zdravljenju bolnikov s pljučnim rakom. To kaže na izjemen napredek na področju razumevanja onkogeneze in biologije pljučnega raka ter s tem razvoja novih zdravil. Breme pljučnega raka ostaja veliko, saj je pljučni rak pri nas in v svetu še vedno najpogostejši vzrok smrti zaradi raka. Za vsako peto smrt zaradi raka je odgovoren pljučni rak. Skoraj tretjina bolnikov s pljučnim rakom ne prejme specifičnega onkološkega zdravljenja, bodisi zaradi slabega stanja zmogljivosti, spremljajočih bolezni ali obsega bolezni. Polovica bolnikov ima ob diagnozi razsejano bolezen, zaradi česar izboljšanje preživetja z malimi koraki sledi napredku v zdravljenju bolnikov s pljučnim rakom. Ti podatki nas opominjajo, da se bomo morali za velike premike v obravnavi bolnikov s pljučnim rakom lotiti drugačnih pristopov. Kot najbolj obetavno se ponuja zgodnje odkrivanje bolezni, ko so možnosti ozdravitve pljučnega raka najboljše. Zapisana Priporočila so usmeritev za obravnavo bolnikov s pljučnim rakom. Le s sodobnim multidisciplinarnim pristopom obravnave lahko bolniku ponudimo zdravljenje, ki mu omogoča najboljši izhod prognostično neugodne bolezni.
Keywords: pljučni rak, priporočila
Published in DiRROS: 27.07.2023; Views: 619; Downloads: 238
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Nuklearna medicina : diagnostika in teranostika
Luka Ležaič, 2016, published professional conference contribution

Keywords: nuklearna medicina, radiofarmaki, diagnostika, teranostika
Published in DiRROS: 17.09.2019; Views: 2217; Downloads: 617
.pdf Full text (639,36 KB)

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PET/CT z 18F-Fgd pri uroloških malignomih
Luka Ležaič, 2013, published professional conference contribution

Keywords: slikovna diagnostika, tomografija, urološki malignomi
Published in DiRROS: 17.09.2019; Views: 2043; Downloads: 595
.pdf Full text (111,41 KB)

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