Perfuzní CT (PCT) je metoda využívaná k hodnocení mikrovaskularizace orgánů. V oblasti jater umožňuje posoudit nejen celkovou perfuzi, ale i odlišit její arteriální a portální složku. Díky tomu je možné hodnotit míru neoangiogeneze v nádorových ložiscích a její změny v rámci terapie. PCT také přispívá k hodnocení změn vaskularizace u chronických hepatopatií. Zásadní kvalitativní posun nastal se zavedením přístrojů s velkým počtem řad detektorů, které umožňují zobrazit perfuzi v rozsahu celého orgánu. Perfuzní CT tak lze využít nejen pro podrobnější hodnocení již známých nádorových ložisek, ale i k jejich vyhledávání.
Perfusion CT (PCT) is a method used for the assessment of microvascularisation. In liver it enables to evaluate not only total perfusion, but also to distinguish between it's arterial and portal component. Thanks to this possibility is this method able to evaluate neoangiogenesis in tumorous tissue and it's reaction to the therapy. It is also contributing in the diagnostics of chronic heepatopathies. Substantial qualitative shift arose after introduction of multidector computed tomography with high number of detector rows, that allows to examine the whole volume of the liver and so perfusion CT can be utilized not only for more detailed evaluation of known tumors but also for their detection.
- Keywords
- jaterní nádory, cirhóza,
- MeSH
- Biological Therapy methods utilization MeSH
- Diagnosis, Differential MeSH
- Financing, Organized MeSH
- Carcinoma, Hepatocellular diagnosis MeSH
- Liver Cirrhosis diagnosis etiology MeSH
- Liver Circulation MeSH
- Catheter Ablation methods utilization MeSH
- Contrast Media diagnostic use MeSH
- Humans MeSH
- Neoplasm Metastasis diagnosis prevention & control MeSH
- Liver Neoplasms diagnosis etiology MeSH
- Perfusion MeSH
- Perfusion Imaging methods instrumentation utilization MeSH
- Tomography, X-Ray Computed history methods utilization MeSH
- Postoperative Care methods utilization MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review 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.
BACKGROUND: While 4 randomized controlled clinical trials confirmed the early benefits of hypothermic oxygenated machine perfusion (HOPE), high-level evidence regarding long-term clinical outcomes is lacking. The aim of this follow-up study from the HOPE-ECD-DBD trial was to compare long-term outcomes in patients who underwent liver transplantation using extended criteria donor allografts from donation after brain death (ECD-DBD), randomized to either HOPE or static cold storage (SCS). METHODS: Between September 2017 and September 2020, recipients of liver transplantation from 4 European centers receiving extended criteria donor-donation after brain death allografts were randomly assigned to HOPE or SCS (1:1). Follow-up data were available for all patients. Analyzed endpoints included the incidence of late-onset complications (occurring later than 6 months and graded according to the Clavien-Dindo Classification and the Comprehensive Complication Index) and long-term graft survival and patient survival. RESULTS: A total of 46 patients were randomized, 23 in both arms. The median follow-up was 48 months (95% CI: 41-55). After excluding early perioperative morbidity, a significant reduction in late-onset morbidity was observed in the HOPE group (median reduction of 23 Comprehensive Complication Index-points [p=0.003] and lower incidence of major complications [Clavien-Dindo ≥3, 43% vs. 85%, p=0.009]). Primary graft loss occurred in 13 patients (HOPE n=3 vs. SCS n=10), resulting in a significantly lower overall graft survival (p=0.029) and adverse 1-, 3-, and 5-year survival probabilities in the SCS group, which did not reach the level of significance (HOPE 0.913, 0.869, 0.869 vs. SCS 0.783, 0.606, 0.519, respectively). CONCLUSIONS: Our exploratory findings indicate that HOPE reduces late-onset morbidity and improves long-term graft survival providing clinical evidence to further support the broad implementation of HOPE in human liver transplantation.
- MeSH
- Humans MeSH
- Brain Death MeSH
- Follow-Up Studies MeSH
- Perfusion methods MeSH
- Graft Survival MeSH
- Liver Transplantation * adverse effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Randomized Controlled Trial MeSH
It should be expected that the hepatic blood flow increase in the cases with liver metastasis. We aimed to find out if there is a correlation between Doppler parameters and hepatic metabolic activity in oncology patients. 35 patients with hepatic metastases who were identified by 18F-fluorodeoxyglucose positron emission tomography scan and assessed with Doppler ultrasound were included in this prospective study. Patients with hepatic disease, cardiac dysfunction, dehydration, history of alcoholism, intake of antihypertensive or vasoactive medication were excluded. Volume flow of the proper hepatic artery and the portal vein were measured in the hepatoduodenal ligament by Doppler sonography. Doppler perfusion index (the ratio of the hepatic artery flow to the total liver blood flow) and flow volumes of 31 age matched subjects were compared. Both flow of the proper hepatic artery and portal vein were found to be significantly higher in patients with liver metastasis. The mean Doppler perfusion index value was 0.2 ± 0.13 in hepatic metastases whereas 0.13 ± 0.05 in control group. Doppler perfusion index was significantly higher in liver metastases (p=0.008). A positive correlation was found between the maximum standardized uptake value of the liver and flow volume of the proper hepatic artery (r=0.774, p=0). Blood flow of the proper hepatic artery and Doppler perfusion index correlates with hepatic standardized uptake value. Flow measurements of the liver may become an important parameter for selecting patients for further positron emission tomography scan and following-up the response after systemic and local therapeutic procedures.
- MeSH
- Adult MeSH
- Hemodynamics * MeSH
- Middle Aged MeSH
- Humans MeSH
- Liver Neoplasms blood supply metabolism secondary ultrasonography MeSH
- Prospective Studies MeSH
- Regional Blood Flow * MeSH
- Aged MeSH
- Ultrasonography, Doppler * MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
