Perfusion analysis
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Annals of the New York Academy of Sciences, ISSN 0077-8923 Volume 473, Issue 1 (December 15, 1986)
xii, 560 stran : ilustrace ; 23 cm
- MeSH
- chování účinky léků MeSH
- elektrochemie MeSH
- mozek - chemie MeSH
- neurochemie metody MeSH
- perfuze MeSH
- psychiatrie MeSH
- Publikační typ
- kongresy MeSH
- sborníky MeSH
- Konspekt
- Psychologie
BACKGROUND: In randomized clinical trials, mechanical thrombectomy (MT) was proved to be a highly effective treatment of acute ischemic stroke which improved clinical outcomes. Some of the trials used automated computed tomography perfusion (CTP) analysis for selection of participants. We present a single-center experience with CTP selection and comparison with CTP trials. METHODS: Data of consecutive MT patients (from January 2016 to December 2017) were retrospectively reviewed. All patients with multiphase CT angiography confirmed the presence of anterior circulation large vessel occlusion/s in the intracranial internal carotid artery and/or middle cerebral artery (M1 or M2) and with admission brain CTP analyzed by RAPID software were included into the analysis. RESULTS: Sixty-two patients fulfilled the inclusion criteria (mean age was 70.1 ± 13.6 years, females 48.5%). At baseline, National Institutes of Health Stroke Scale score was 16 (IQR = 13-20), Alberta Stroke Program Early CT Score (ASPECTS) was 8 (IQR = 7-9), CTP core volume was 20 mL (IQR = 2-36), and CTP penumbra volume was 145.5 mL (IQR = 107-184). Time from stroke onset to imaging was 1 hour 32 minutes, time from stroke onset to reperfusion was 3 hours 50 minutes, and median time from CT to reperfusion was 1 hour 56 minutes. Modified thrombolysis in cerebral infarction 2b/3 was achieved in 42 patients (67.7%). Twenty-three patients (37%) had modified Rankin scale 0-2 at 90 days. CONCLUSIONS: Our analysis of CTP-selected patients for MT supports clinical applicability of automated CTP analysis into everyday clinical practice.
- MeSH
- cévní mozková příhoda diagnostické zobrazování patofyziologie chirurgie MeSH
- CT angiografie metody MeSH
- ischemie mozku diagnostické zobrazování patofyziologie chirurgie MeSH
- klinické rozhodování * MeSH
- klinické zkoušky jako téma metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- mozkový krevní oběh * MeSH
- perfuzní zobrazování metody MeSH
- posuzování pracovní neschopnosti MeSH
- prediktivní hodnota testů MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- trombektomie metody MeSH
- výběr pacientů * MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
It has been shown that besides positron emission tomography, single photon emission computed tomography and magnetic resonance imaging; contrast echocardiography can be used for qualitative and quantitative myocardial perfusion assessment. In this review, the properties of ultrasound contrast agents, imaging techniques and acquisition methods are shortly described and the possibilities of perfusion echocardiography are summarized. The main focus is put on the description of three perfusion models: mathematical models, physical models assuming an ideal inflow and physical models including inflow measurement.
- MeSH
- echokardiografie MeSH
- interpretace obrazu počítačem MeSH
- kontrastní látky diagnostické užití MeSH
- koronární cirkulace MeSH
- lidé MeSH
- modely kardiovaskulární MeSH
- prediktivní hodnota testů MeSH
- zobrazování myokardiální perfuze metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
BACKGROUND: Donation after circulatory death donors are becoming a common source of organs for transplant. Despite good long-term outcomes of grafts from donation after circulatory death, this group is affected by a higher occurrence of delayed graft function and primary nonfunction. Our hypothesis is based on the assumption that washing the kidney grafts in the donor's body using a simple mechanical perfusion pump will result in faster and better perfusion of the parenchyma and more efficient cooling compared with hydrostatic perfusion alone. METHODS: A total of 7 experimental animals (pigs) were used. The animals were divided into 2 groups: group A (n = 3) and group B (n = 4). After a 30-minute ischemic period for the selected kidney (clamped renal vessels), intra-arterial perfusion was performed. In group A perfusion was performed using hydrostatic pressure; in group B mechanical controlled perfusion was performed. After perfusion, declamping of the renal vessels caused restoration of flow. For graft quality evaluation, biopsy specimens were harvested, and the cooling speed was observed. Laboratory markers or renal failure were determined. RESULTS: We found no significant differences between temperature drop and total diuresis between groups A and B. A significant difference was found between the groups in both flow parameters (flow maximum and mean flow) (P = .007, respectively P = .019). No laboratory parameters were found to be statistically significantly different. Histopathological analysis strongly supports the hypothesis of better flushing of kidney grafts using mechanical perfusion. CONCLUSIONS: Based on our results, better kidney graft quality can be expected after immediately started mechanical perfusion in situ.
- MeSH
- dárci tkání MeSH
- ledviny MeSH
- opožděný nástup funkce štěpu MeSH
- perfuze MeSH
- prasata MeSH
- přežívání štěpu MeSH
- smrt MeSH
- transplantace ledvin * MeSH
- uchovávání orgánů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Perfusion Index (PI) is an important vital sign in medical practice, with increasing utility in a variety of medical specialties. Its relevance extends to critical care and serves as a valuable measure of anesthetic efficacy. Despite its growing importance, there is a notable lack of literature on the potential impact of different surgical positions on PI measurements. Therefore, this study attempts to fill this gap by investigating whether PI exhibits variance in four different surgical positions: supine, prone, right and left lateral decubitus. The interventional prospective study included 27 volunteers who underwent PI measurement in each position in a randomized order. Using a one-way analysis of variance (ANOVA) for repeated measures, the results showed that at a 5% significance level, no significant differences were found in measured PI values between supine, prone, right and left lateral decubitus positions. Higher standard deviations in the right (±4.46%) and left (±4.58%) lateral decubitus positions indicate greater PI variability than in the supine (±3.91%) and prone (±3.88%) positions. The results suggest consistency of PI measurements across different surgical positions, adding to the knowledge of standardization of PI measurements and interpretation of measured absolute PI values.
- MeSH
- lidé MeSH
- oxymetrie metody MeSH
- perfuzní index * MeSH
- postura těla MeSH
- prospektivní studie MeSH
- Check Tag
- lidé MeSH
A convenient geometrical description of the microvascular network is necessary for computationally efficient mathematical modelling of liver perfusion, metabolic and other physiological processes. The tissue models currently used are based on the generally accepted schematic structure of the parenchyma at the lobular level, assuming its perfect regular structure and geometrical symmetries. Hepatic lobule, portal lobule, or liver acinus are considered usually as autonomous functional units on which particular physiological problems are studied. We propose a new periodic unit-the liver representative periodic cell (LRPC) and establish its geometrical parametrization. The LRPC is constituted by two portal lobulae, such that it contains the liver acinus as a substructure. As a remarkable advantage over the classical phenomenological modelling approaches, the LRPC enables for multiscale modelling based on the periodic homogenization method. Derived macroscopic equations involve so called effective medium parameters, such as the tissue permeability, which reflect the LRPC geometry. In this way, mutual influences between the macroscopic phenomena, such as inhomogeneous perfusion, and the local processes relevant to the lobular (mesoscopic) level are respected. The LRPC based model is intended for its use within a complete hierarchical model of the whole liver. Using the Double-permeability Darcy model obtained by the homogenization, we illustrate the usefulness of the LRPC based modelling to describe the blood perfusion in the parenchyma.
Cíl: Analyzovat variabilitu intrakraniální cirkulace, navrhnout optimalizaci protokolu pro pacienty s ischemickou cévní mozkovou příhodou (CMP) a ověřit proveditelnost nového protokolu. Metodika: Retrospektivně byl zhodnocen testovací soubor 46 pacientů, u kterých bylo provedeno perfuzní CT vyšetření mozku při podezření na CMP a zároveň nebyla prokázána významná stenóza či okluze karotického a intrakraniálního řečiště. U těchto osob byla provedena analýza časového průběhu intrakra-niální cirkulace v tepenném a žilním systému. Na základě této analýzy byla navržena úprava délky a časování perfuzního CT vyšetření mozku pomocí testovacího bolusu kontrastní látky. Optimalizovaným protokolem (20 opakovaných skenů s délkou 1,5 s v rozsahu celého mozku) byly postupně vyšetřeny dvě skupiny pacientů, kdy byla použita odlišná hodnota napětí na rentgence (80 kV a 70 kV). U těchto pacientů byla provedena analýza kvality vyšetření a radiační zátěže pomocí standardních ukazatelů dávky CTDIvol a DLP. Výsledky: Pouze u jednoho pacienta bylo u optimalizovaného protokolu perfuzní CT vyšetření nehodnotitelné, u všech ostatních vyšetření bylo dosaženo optimální kvality zobrazení pro hodnocení. Bylo dosaženo snížení hodnot CTDIvol a DLP při perfuzním CT mozku u obou optimalizovaných protokolů. U testovacího souboru byla průměrná hodnota CTDIvol 130,37 mGy, průměrná hodnota DLP byla 2068,17 mGy?cm. U optimalizovaného protokolu byla průměrná hodnota CTDIvol 85,64 mGy a průměrná hodnota DLP 1326,44 mGy?cm, u optimalizovaného protokolu se sníženým napětím na 70 kV byla průměrná hodnota CTDIvol. 50,57 mGy a průměrná hodnota DLP 783,42 mGy?cm. Závěr: Optimalizace spuštění a redukce délky perfuzního CT mozku je možná na základě hodnot z testovacího bolusu kontrastní látky. Kombinací s nízkonapěťovým protokolem lze výrazně snížit radiační zátěž.
Aim: To analyze variability of intracranial circulation and to design optimization of protocol for patients with acute ischemic stroke and to verify feasibility of new protocol. Method: The test group of 46 patients with suspected acute ischemic stroke, which underwent perfusion CT of the brain and CT angiography, was retrospectively assessed. CT angiography did not prove significant stenosis or occlusion of arteries. By these patients, time of intracranial circulation in arteries and veins was analyzed. Based on this analysis, adjustment of length and timing of perfusion CT of the brain was established with the help of test bolus technique of contrast agent. Two groups of patients were examined according to optimized protocols (20 repeated scans, one scan within 1.5 seconds, whole brain was covered) with different voltage on X-ray tube (80 kV and 70 kV). Volume CT dose index (CTDIvol) and dose length product (DLP) were assessed as standard indicators of dose. Results: All examinations were evaluated as adequate from the point of view of diagnostic quality of examination. Only one examination in the optimized protocol with 70 kV was not evaluable. CT dose index and dose length product were reduced in both optimized perfusion CT protocols. Mean value of CTDIvol and DLP was 130.37 mGy and 2068.17 mGy?cm in the test group. Mean value of CTDIvol and DLP was 85.64 mGy and 1326.44 mGy ? cm in the optimized protocol and 50.57 mGy and 783.42 mGy?cm in the optimized protocol with voltage reduced to 70 kV. Conclusion: Optimization of start and reduction of length of perfusion CT of the brain is possible based on test bolus technique of contrast agent. It is possible to significantly reduce dose with the help of low voltage protocol.
- MeSH
- chemoterapie nádorů pomocí regionální perfúze MeSH
- diagnostické zobrazování metody MeSH
- dospělí MeSH
- funkce levé komory srdeční MeSH
- infarkt myokardu diagnóza patologie MeSH
- lidé MeSH
- nukleární lékařství metody MeSH
- počítačové zpracování obrazu MeSH
- radioisotopová ventrikulografie metody MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- srovnávací studie MeSH
Long-term continuous protein production can be reached by perfusion operation. Through the continuous removal of waste metabolites and supply of nutrients, steady-state (SS) conditions are achieved after a certain transient period, where the conditions inside the reactor are not only uniform in space but also constant in time. Such stable conditions may have beneficial influences on the reduction of product heterogeneities. In this study, we investigated the impact of perfusion cultivation on the intracellular physiological state of a CHO cell line producing a monoclonal antibody (mAb) by global transcriptomics and proteomics. Despite stable viable cell density was maintained right from the beginning of the cultivation time, productivity decrease, and a transition phase for metabolites and product quality was observed before reaching SS conditions. These were traced back to three sources of transient behaviors being hydrodynamic flow rates, intracellular dynamics of gene expression as well as metabolism and cell line instability, superimposing each other. However, 99.4% of all transcripts and proteins reached SS during the first week or were at SS from the beginning. These results demonstrate that the stable extracellular conditions of perfusion lead to SS also of the cellular level.
- MeSH
- buněčné kultury metody MeSH
- CHO buňky MeSH
- Cricetulus MeSH
- glykosylace MeSH
- monoklonální protilátky analýza genetika MeSH
- perfuze metody MeSH
- proteom analýza genetika MeSH
- proteomika metody MeSH
- transkriptom * MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
