Varinex

DOI: 10.17489/biohun/2011/2/0

Additív gyártástechnológiák alkalmazhatósági vizsgálata testreszabott orvosi implantátumok méretezéséhez

Az egyedi, testreszabott implantátumoknak számos előnye ismert. Ahhoz, hogy azok valóban tökéletesen, vagy ahhoz közelitő módon legyenek felhasználhatók igen sok szempontot kell figyelembe venni már a tervezési fázisban is. Bármilyen bonyolult, tökéletesen illeszkedő geometriát CT felvételsorozatból - a megfelelő paraméterek beállítása után - CAD geometriaként azonnal elő tudunk állítani. Ebből némi fájlkonverzió után egy - a 3D nyomtató bemeneteként ismert – stl formátumot könnyen készíthetünk. Így a szükséges geometria legyártása az additív gyártástechnológiákkal elvégezhető. Ezekkel az eljárásokkal létrehozhatjuk az orvosi implantátumokat, de elengedhetetlen tervezésükhöz a megfelelő anyagmodell kiválasztása és az anyagjellemzők pontos ismerete. Nélkülük megfelelő méretezés nem képzelhető el, mert a nem megfelelően méretezett implantátumok váratlanul, nem tervezett időpontban való tönkremenetele további problémákat is okozhat A legismertebb 3D nyomtatási eljárások leggyakrabban használt anyagainak összehasonlító vizsgálatával bemutatjuk, hogy az egyes eljárásokkal gyártott alkatrészek, implantátumok viselkedése milyen mechanikai modellel és milyen anyagjellemzőkkel írhatók le. Összehasonlítjuk az OBJET Polyjet Fullcure720, az FDM eljárás PLA, valamint az SLS eljárás elvén előállított PA anyagokat

Egyedi célzók fejlesztése McMinn vápához

A kiterjedt, Paprosky ≥ 2b periacetabularis csontdefektusok rekonstrukciója során saját gyakorlatunkban elsődleges választásunk a Waldemar Link (Hamburg, Németország) McMinn 1. típusú stemmed vagy más néven ice cream cone shaped vápájának használata. Ezekben az esetekben műtéttechnikai nehézséget jelent, hogy a műszerkészlet primer, azaz számottevő csontdefektus nélküli esetekre készült. Ezért saját technikát dolgoztunk ki az ice cream cone shaped vápa beültetésére olyan esetekre, ahol a gyári instrumentárium által használt referencia pontok hiányoznak. A módszer lényege, hogy a csípőlapát elülső részébe percutan két titán spongiosa csavart helyezünk be célzási referencia pontként, majd Metal Artifact Removal üzemmódban CT felvételt készítünk az operálandó medencefélről, ami alapján megtervezzük a behelyezendő vápa helyzetét, és a behelyezéshez szükséges célzódrót biztonságos bevezetéséhez egyedi tervezésű, biokompatibilis és sterilizálható alapanyagú, 3D nyomtatott célzót készítünk. Ezáltal a műtét minimális röntgen dózis mellett, az előzetes tervet jól reprodukáló módon végezhető el. Beszámolunk a tervezés orvosi és mérnöki technikai feladatairól, a műtéti technikáról, és a 2018 óta operált első 18 eset főbb tanulságairól

Synovitis and bone inflammation in early rheumatoid arthritis: high-resolution multi-pinhole SPECT versus MRI

PURPOSEWe aimed to assess the relationship between bone inflammation in multi-pinhole single-photon emission computed tomography (MPH-SPECT) and synovitis detected by magnetic resonance imaging (MRI) in early rheumatoid arthritis patients. MATERIALS AND METHODSMPH-SPECT with technetium dicarboxypropanedisphosphonate (Tc-99mDPD) and 3 Tesla MRI were performed in 10 early rheumatoid arthritis patients. Eighty finger joint sites were assessed for increased osteoblastic activity using visual and region-of-interest (ROI) analysis. Presence of joint inflammation in MRI was investigated using the subscores of the rheumatoid arthritis MRI score. RESULTSTc-99mDPD uptake was increased in 38 (47.5%) and 22 (27.5%) joint sites as determined by visual and ROI analysis, respectively. A total of 32 (84.2%) sites with increased bone metabolism showed a normal MRI bone signal. The MPHSPECT uptake ratio was elevated only in the subgroup with severe synovitis (P < 0.001). CONCLUSIONIn early rheumatoid arthritis, molecular imaging with MPHSPECT detects higher rates of inflammatory bone involvement compared to MRI. Our preliminary data suggest that osteitis is related to severe synovitis

System size and centrality dependence of the balance function in A + A collisions at sqrt s NN = 17.2 GeV

Electric charge correlations were studied for p+p, C+C, Si+Si and centrality selected Pb+Pb collisions at sqrt s_NN = 17.2$ GeV with the NA49 large acceptance detector at the CERN-SPS. In particular, long range pseudo-rapidity correlations of oppositely charged particles were measured using the Balance Function method. The width of the Balance Function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions

Data-driven transcriptomics analysis identifies PCSK9 as a novel key regulator in liver aging. (Histology Images)

These are the histology images on "Data-driven transcriptomics analysis identifies PCSK9 as a novel key regulator in liver aging.

Application of the cross sectional diagnostic imaging methods (CT and MR) in anatomical 3D reconstructions Part 1. CT based modeling of the air containing parts

SUMMARY Background: Computed tomography (CT) became an important diagnostic imaging method in the veterinary practice in the past decades. Data gained with the scanning can be used for 3D displaying of organs or body regions as well. The viewer softwares provide more and more options for reconstruction of the target area.Objectives: The authors present their own results about the 3D reconstruction of the avian air sacs (turkey) and the paranasal sinuses of the horse head based on data gained with a Siemens Definition Flash Dual CT.Materials and Methods: A Siemens Definition Flash Dual Source 2 x 128 slices CT was used to scan 5 male turkey toms at the age of 20 weeks. A head of a 7 years old stallion cadaver was examined with the same scanner. The resulting DICOM data were reconstructed with the 3DSlicer software using manual and semi-auto-matic segmentations, focusing on the air sac system and the paranasal sinuses. Results and discussion: Based on the Hounsfield Unit (HU) of the air the authors created 3D models of the avian air sac system, the nasal cavity, the guttural pouch and paranasal sinuses of the horse. The slice thickness of the scans (2 mm for the turkeys and 0.6 mm for the horse head) were sufficient to generate anatomically correct and detailed shape of the above-mentioned parts of the airways. The methods used for these reconstructions can be used for other organs, organ systems or body regions as well but require high contrast difference between the different anatomical structures or tissues. If such contrast deviations are not present naturally, contrast enhancement for the scanning procedures (in vivo contrast media administration, post mortem contrast enhancement methods) could be used. The resulted 3D anatomical models can be used in education, surgical planning and in animal breeding. In the second part of this article series the authors will present the bony and soft tissue model of the equine stifle joint, based on CT and MR image fusion

Application of the cross sectional diagnostic imaging methods (CT and MR) in anatomical 3D reconstructions Part 2. Soft tissue and bone reconstruction. CT and MR fusion modeling of the equine stifle joint

SUMMARY Background: Computed tomography (CT) and magnetic resonance imaging (MR) became important diagnostic tools in the veterinary practice in the past decades. Data gained with those scanning methods can be used for 3D displaying of different organs, organ systems and body regions as well. There are numerous reconstructional soft-wares to create high detailed and precise 3D anatomical models of the target area, based on those datasets.objectives: The authors present their own results about the 3D reconstruction of the bony and soft tissues of the equine stifle joint, based on image fusion of CT and MR data.Material and Methods: A Siemens Definition Flash Dual Source 2x128 slices CT and a Simens Avanto 1.5T MR scanner was used to scan the stifle joint of an 8 years old mare horse. The resulting DICOM data were reconstructed with the 3DSlicer software using manual, semi-automatic and automatic segmentations. First the bony structures of the stifle were reconstructed from the CT dataset. The soft tissues of the stifle joint: cavities of the femoropatellar, medial femorotibial, lateral femorotibial, subextensory recess of the lateral femorotibial joints, the menisci, and the different ligaments were reconstructed after the image fusion of the MR data with the 3D bony model from created from the CT.Results and discussion: In the second part of this article series the authors give a short review about the technical details of the MR imaging method, the CT and MR anatomy of the equine stifle and the procedure how they created the 3D model. The authors created 3D models from the bones of the equine stifle from the CT data set. In the second step they made an image fusion with the MR data of the same stifle joint. The methods used for these reconstructions can be used for other organs, organ systems or body regions as well but require high contrast difference between the different anatomical structures or tissues. If such contrast deviations are not present naturally, contrast enhancement for the scanning procedures (in vivo contrast media administration, post mortem contrast enhancement methods) could be used