Bosniak category III cysts are more likely to be malignant than we expected in the era of multidetector computed tomography technology

Background: Complex indeterminate Bosniak category III renal cystic masses are traditionally considered to be malignant in 50%. Our aim was to retrospectively evaluate the attenuation characteristics in multiphase computed tomography (CT) and to determinate the incidence of malignancy based on histological findings on all Bosniak category III renal cystic masses investigated in our department between April 3, 2007 and November 21, 2013. Materials and Methods: Quadriphasic multidetector CT images of nineteen patients (mean age: 56.5 +/- 16.5 years) with radiologically detected Bosniak category III lesions were reviewed retrospectively. All lesions were surgically removed, and the incidence of malignancy, based on pathological results was determined. Results: Calcification was present in four lesions (21%). The mean largest diameter was 48.7 +/- 28.8 mm. All lesions were multilobulated and septated. Of the 19 removed lesions, 16 (84%) were malignant, and 3 (16%) were benign (one inflammatory cyst including a nephrolith, one cystic nephroma and one atypical angiomyolipoma). CT and histological findings of 19 Bosniak III cysts were correlated. Conclusion: Our study demonstrated much higher prevalence of malignancy (84%) in radiologically detected Bosniak category III cysts than it has been described before. It may due to the era of modern multidetector CT technology and multiphase protocol

Assessment of a large volume maxillofacial CBCT system-from biomechanical point of view-as a tool to build patient customized bio-models

AbstractThe number of patients diagnosed with cancer is reaching a scarily high number worldwide. This is no different in the area of mandible cancer. Unfortunately Hungary is quite high up in the ladder. The registered known number of patients with mandible cancer and the associated number of death occurrences are also showing signifi cant data in the country. However it is easy to diagnose, alcohol consumption and smoking or just bad oral hygiene really pushes the statistics. Inside the oral cavity, in case of mandible cancer and late diagnosis the only viable solution is the bone resection. To determine the extent of the cancer and to carefully plan the surgery procedure or in case of models which were created for biomechanical examinations, the medical science more and more often uses the image based processes and tools. Next to the realistically built models a more punctual mechanical parameter simulation becomes possible. It is highly important that the necessary information is extracted from the patients with the least stress. With the shortest time and smallest radiation the image must be made in a way that the scan can be well evaluated and it is usable. Within the current examination in the medical fi eld of imaging methods a gold standard MSCT and a specifi cally in the head-neck region used CBCT methods will be compared specifi cally from biomechanical modelling point of view. During the comparison the gray value was examined by the use of a cadaver head. The results show that the gray values provided by CBCT differs slightly from the MSCT values that is considered as reference. The more extent absolute error occurs with less frequency. Based on these facts the CBCT can be used for the density based material comparison for biomechanical models with less radiation dose.DOI: 10.17489/biohun/2014/2/0

Compression test of the mandibular cortical bone: A cadaver study assessing formalin treated or macerated bone specimens

AbstractNowadays the examination of implants from engineering point of view is becoming more and more supported in the medical fi eld. Instead of the more problematic cadaver examination, the computer based simulations are growing more popular. The examinations must be validated to be able to stay with the realistic situation. Using these engineering methods it became possible to do measurements on the reconstructions of a human resectioned mandible. The creation of the bone models is one of the most varying fields in the biomechanical simulation. In the literature a wide range of Young modulus for the bone cortical layers can be found and these values are actively used even in different further fi nite element simulation researches. However the proper modeling of the cortical layer thickness and correctly calibrated mechanical parameter settings bare key importance regarding the stability and connection of the implants and the fi xing screws. The values of the Young modulus are depending on many factors, for example gender or even the age, not even mentioning further different infl uencing factors. In this study destructive biomechanical examinations were carried out on bones received from dead people. The samplings of the bone were conducted from the area of the screwing used in the mandible reconstruction. Considering the results it can be concluded that the values in the literature are often not as accurate. Regarding orthotropic values of the mandible, so far has only been a small segment of information was covered. The measured values are lower than the ones in the literature. In case of the highest value it is still 3.5 GPa Young modulus in the axial direction. The results can be used in order to create a more reliable model combined with a more realistic Young modulus for the fi nite element simulation of the bone models. On these models the different scenarios of the resection cases can be estimated more precisely with examinations.DOI: 10.17489/biohun/2014/2/0

Kezdeti tapasztalataink az mpMR fúziós ultrahangvezérelt prosztatabiopsziával

Bevezetés: A prosztatarák diagnosztikájában az utóbbi években paradigmaváltás történt. Az MR-vizsgálat fejlődése lehetővé tette a prosztatatumor gyanús elváltozásainak célzott mintavételét. Az mpMR fúziós biopszia pontos és költséghatékony módszer. Célkitűzés: Célkitűzésünk az volt, hogy összegezzük az mpMR fúziós biopsziák terén szerzett tapasztalatainkat. Módszer: A Semmelweis Egyetem Urológiai Klinikáján 2017 és 2019 között 40, mpMR fúziós biopsziát végeztünk a BioJet-program segítségével, transperinealis behatolásból. Az MR-vizsgálatok kiértékelése a PI-RADS v2 ajánlása szerint történt. Megvizsgáltuk, hogy a laesiók PI-RADS-besorolása, elhelyezkedése, mérete, az extraprosztatikus terjedés jeleinek megléte, a páciensek PSA-, illetve PSAD-értékei, valamint a prosztata volumene befolyásolja-e a mintavételek kimenetelét. Eredmények: A célzott mintavételek során pácienseink 80%-ánál igazolódott malignitás. PI-RADS 5. és 4. besorolású laesiók esetén a detektációs ráta 91%, illetve 85%, míg PI-RADS 3. laesióknál 20% volt. A perifériás zóna elváltozása- inál szignifikánsan magasabb volt a pozitív eredmény valószínűsége, mint a tranzicionális zóna laesióinál (khi2(1) = 6,555, p = 0,010, Fisher-féle egzakt p = 0,017, V = 0,355). Az extraprosztatikus terjedés jelei és a magasabb PSAD- értékek növelték a pozitív minták valószínűségét (khi2(1) = 7,704, p = 0,006, Fisher-féle egzakt p = 0,004, V = 0,355; illetve 0,47 ± 0,50 ng/ml2 vs. 0,18 ± 0,17 ng/ml2; Z = 3,447, p<0,001), míg az elváltozások mérete nem befolyá- solta a kimenetelt. A prosztatavolumen szignifikánsan magasabb volt azoknál, akiknél nem igazolódott malignitás (50,9 ± 18,8 ml vs. 119,6 ± 91,6 ml; Z = –3,505, p<0,001). Következtetések: Az elvégzett fúziós biopsziák detektációs rátája magasabb volt az irodalmi átlagnál. Eredményeink alapján a mintavételek kimenetelét befolyásolhatja az elváltozások PI-RADS-besorolása, elhelyezkedése, az extra- prosztatikus terjedés, a PSAD-értékek, valamint a prosztatatérfogat. A fenti szempontok figyelembevételével kivá- laszthatók azok a páciensek, akik a legtöbbet profitálhatnak a beavatkozásból

Hybrid FPGA&ndash;CPU-Based Architecture for Object Recognition in Visual Servoing of Arm Prosthesis

The present paper proposes an implementation of a hybrid hardware&ndash;software system for the visual servoing of prosthetic arms. We focus on the most critical vision analysis part of the system. The prosthetic system comprises a glass-worn eye tracker and a video camera, and the task is to recognize the object to grasp. The lightweight architecture for gaze-driven object recognition has to be implemented as a wearable device with low power consumption (less than 5.6 W). The algorithmic chain comprises gaze fixations estimation and filtering, generation of candidates, and recognition, with two backbone convolutional neural networks (CNN). The time-consuming parts of the system, such as SIFT (Scale Invariant Feature Transform) detector and the backbone CNN feature extractor, are implemented in FPGA, and a new reduction layer is introduced in the object-recognition CNN to reduce the computational burden. The proposed implementation is compatible with the real-time control of the prosthetic arm

Clear cell renal cell carcinoma and papillary renal cell carcinoma: differentiation of distinct histological types with multiphase CT

PURPOSE: Conventional clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC) have different behavioral characteristics and clinical management strategies (nephrectomy vs. nephron-sparing surgery). Our aim was to retrospectively evaluate the contrast enhancement pattern of ccRCC and pRCC and evaluate its possible diagnostic role for preoperative differentiation using a standardized protocol. MATERIALS AND METHODS: Quadriphasic multidetector computed tomography (CT) images (unenhanced, corticomedullary, nephrographic, and excretory phases) of 19 patients with 20 ccRCC and 14 patients with 15 pRCC lesions (mean ages, 62.3+/-14.1 and 61.4+/-13.7 years, respectively) were reviewed retrospectively. The attenuation characteristics were compared with the attenuation of the normal renal cortex using either multiple 10-mm2 regions of interest or whole tumor attenuation measurements. The degree of contrast enhancement was also compared. RESULTS: Univariate analysis revealed that ccRCC lesions showed higher mean attenuation values on the corticomedullary and nephrographic phases compared with pRCC masses (P < 0.05) using both measurement techniques. CONCLUSION: The findings underscore the importance of multiphase CT in the differentiation of these two subtypes of RCC using standard assessment techniques. The measurement of the degree of enhancement on contrast-enhanced multidetector CT may be a simple and useful method to radiologically differentiate between the two histological types of RCC