3 research outputs found

    The significance of non-invasive advanced MRI techniques in evaluation of renal allograft function

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    Uvod: Perfuzija predstavlja protok krvi u kapilarnom koritu koji određuje dopremanje nutrijenata i kiseonika tkivu, a u bubrezima reguliše stepen glomerulske filtracije (GFR) kao centralnu meru bubrežne funkcije. Razvoj neinvazivne i pouzdane metode za merenje bubrežne perfuzije koja bi oslikavala GFR bi značajno unapredila pravovremeno otkrivanje oštećenja alografta. Cilj: Utvrđivanje kod kojih pedijatrijskih pacijenata alograft ima oštećenu funkciju merenjem kortikalne bubrežne perfuzije (cRBF), uz upoređivanje sa perfuzijom zdravih kontrola korišćenjem tehnike obeležavanja spinova u arterijskoj krvi magnetnom rezonancom (ASL-MRI). Metodologija: Kod 20 pacijenata sa alograftom i 20 zdravih kontrola je izveden ASL-MRI u cilju kvantifikacije cRBF na parametarskim mapama. cRBF je korelirana sa izračunatim GFR kod alografta i upoređivana među grupama pacijenata sa očuvanom (GFR≥60 mL/min/1.73m2) i oštećenom (GFR<60 mL/min/1.73m2) funkcijom, a zatim i sa zdravim kontrolama. Rezultati: cRBF kod pacijenata sa alograftom je bila u rasponu između 85 i 335ml/100gr/min (prosečno 190.05 ± 67.62 mL/100 g/min). Prosečna cRBF kod pacijenata sa dobrom funkcijom je bila značajno višа nego kod pacijenata sa lošom (225.91±64.38mL/min/100g vs. 146.22±41.84mL/min/100g, p=0.005), uz značajnu korelaciju sa GFR kod svih pacijenata (r=0.64, p=0.002). Kod zdravih se prosečan cRBF razlikovao u odnosu na pacijente sa oštećenom funkcijom (322.00±121.36vs. 146.22±41.84ml/100gr/min, p=0.002) dok se nije razlikovao u odnosu na pacijente sa stabilnom funkcijom (322.00±121.36vs.225.91±64.38ml/100gr/min, p=0.056). Zaključak: Neinvazivno izmerena kortikalna bubrežna perfuzija ASL-MRI metodom se razlikuje između pacijenata sa očuvanom i oštećenom funkcijom alografta, sa kojom značajno korelira.Background: Perfusion represents a blood flow at the level of the tissue capillary bed and determines the delivery of nutrients and oxygen, while in kidneys regulates glomerular filtration rate (GFR), as a central measure of renal function. The development of a non-invasive and reliable method for renal perfusion estimation that would reflect GFR would significantly improve on-time identification of potential allograft injury. Aim: Discrimination of renal allografts with impaired function by measuring cortical renal blood flow (cRBF) in pediatric patients, as well as a comparison with cRBF values of healthy controls using magnetic resonance imaging arterial spin labelling (ASL-MRI). Methods: We performed ASL-MRI in 20 allograft patients and 20 healthy controls to calculate cRBF on parameter maps. It was correlated to calculated GFR in allografts and compared between patient groups with good (GFR≥60 mL/min/1.73m2) and impaired allograft function (GFR<60 mL/min/1.73m2) as well as with healthy controls. Results: cRBF in patient group ranged between 85 and 335 mL/100 g/min (mean 190.05 ± 67.62 mL/100 g/min). Mean cRBF in patients with good allograft function was significantly higher than in patients with impaired function (225.91±64.38 vs. 146.22±41.84 mL/min/100g, p=0.005), showing a highly significant correlation with GFR in all subjects (r=0.64, p=0.002). In healthy controls mean cRBF was significantly higher than in patients with poor allograft function (322.00±121.36 vs. 146.22±41.84 ml/100gr/min, p=0.002) and showed no difference to patients with stable function (322.00±121.36 vs. 225.91±64.38 ml/100gr/min, p=0.056). Conclusion: Cortical perfusion as non-invasively measured by ASL-MRI differs between patients with good and impaired allograft function and correlates significantly with its function

    The Effect of Robotic Technology on Perioperative Outcomes in Total Knee Arthroplasty

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    Introduction Robotic technology has recently regained momentum in total knee arthroplasty (TKA) but the effects of this technology on accuracy of implant positioning, intraoperative soft tissue injury and postoperative functional rehabilitation remain unknown. The objectives of this research thesis were to compare a comprehensive range of radiological objectives and perioperative outcomes in conventional jig-based TKA versus robotic-arm assisted TKA, and use optical motion capture technology to quantify the effects of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) resection on knee biomechanics. Methods A series of prospective cohort studies were undertaken in patients with established knee osteoarthritis undergoing primary conventional jig-based TKA versus robotic-arm assisted TKA. Predefined radiological and perioperative study outcomes were recorded by independent observers. Optical motion capture technology during robotic TKA was used to quantify the effects of ACL and PCL resection on knee biomechanics. Results Robotic-arm assisted TKA was associated with improved accuracy of implant positioning, reduced periarticular soft tissue injury, decreased bone trauma, improved postoperative functional rehabilitation, and reduced early systemic inflammatory response compared to conventional jig-based TKA. The Macroscopic Soft Tissue Injury (MASTI) classification system was developed and validated for grading intraoperative periarticular soft tissue injury and bone trauma during TKA. ACL resection created flexion-extension mismatch by increasing the extension gap more than the flexion gap, whilst PCL resection increased the flexion gap proportionally more than the extension gap and created mediolateral laxity in knee flexion but not in extension. Conclusion Robotic-arm assisted TKA was associated with increased accuracy of implant positioning, reduced iatrogenic soft tissue injury, and improved functional rehabilitation compared to conventional jig-based TKA. ACL and PCL resections created unique changes in knee biomechanics that affected flexion-extension gaps and mediolateral soft tissue tension during TKA. On the basis of this thesis, further clinical trials have been established to determine the long-term clinical significance of these findings

    Image-asssited system for the diagnosis of bladder tumor recurrence

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