Cílem článku je seznámit čtenáře s výhodami a nevýhodami sekvence 4D Flow. Vyšetření touto sekvencí umožňuje retrospektivně zjistit průtok a jiné parametry toku v objemu zájmu. Je ovšem náročné jak z hlediska času, tak následného zpracování dat. Pro vysokou cenu komerčních programů může být pro uživatele nutné vytvořit si vlastní nástroje zpracování dat. Komerční programy poskytují omezené nástroje segmentace, ale naopak zvládají všechny základní korekce a nabízí množství funkcionalit. Přes svůj velký potenciál má sekvence svá omezení, zejména je to nízké prostorové rozlišení a dlouhá doba akvizice.
The goal of this paper is to inform about the 4D Flow sequence, its advantages and disadvantages. 4D Flow examination allows to assess flow rate and other flow parameters in the volume of interest retrospectively. However, it is expensive in terms of time and postprocessing. An in-house software may be necessary, as commercial programs remain costly. They offer a number of functionalities and data corrections. Their segmentations tools, however, remain relatively limited. Low spatial resolution and long data acquisition are the primary limitations of the sequence
- Keywords
- 4D Flow,
- MeSH
- Electronic Data Processing * methods MeSH
- Diagnostic Techniques, Cardiovascular instrumentation MeSH
- Humans MeSH
- Magnetic Resonance Imaging * methods MeSH
- Hemorheology MeSH
- Software MeSH
- Data Visualization MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
V současnosti existují dva základní koncepty akvizice dat pro 4D CT-angiografii zobrazení (4DCTA). Prvním je založena na mnohonásobné dynamické akvizici dat po aplikaci bolu kontrastní látky v různých fázích jejího průchodu cévním systémem. Dynamická 4DCTA potom dovoluje zobrazit lokální hemodynamiku cirkulace. Dynamickou 4DCTA lze hodnotit mozkovou cirkulaci, dále dynamiku arteriálního zásobení nádorů a jejich venózní drenáže. Druhý koncept 4DCTA byl odvozen od CT-angiografie srdce a věnčitých tepen s EKG gatingem. Retrospektivní segmentace dat do deseti až dvaceti fází v jednom R-R intervalu je principem zobrazení pulzatorních nebo kývavých pohybů tepen a umožňuje také zobrazit tryskání kontrastní látky při krvácení nebo vířivé mísení kontrastní látky a krve v srdečních síních nebo v aneuryzmatech. Prezentovaná práce podává přehled o možnostech provedení a potenciálních indikacích čtyřdimenzionální CT-angiografie. V práci jsou diskutovány současná omezení této nové zobrazovací metody, jako je zvýšená dávka nebo problémy s pokrytím většího objemu tkáně společně s možnými řešeními nastíněných problémů.
The presented work reviews current technical possibilities and clinical indications of four dimensional angiography using computed tomography (4D-CTA). There are two contemporary concepts of 4D imaging of cardiovascular system. The first is based on dynamic multiple acquisitions after intravenous application of iodinated contrast material with the data acquisitions in several phases of the first pass of the contrast agent. The dynamic 4D-CTA allows to display the hemodynamics in the local circulation like brain vessels or tumorous arterial supply with venous drainage. Second concept was derived from the ECG-gated CT angiography of the heart and coronary arteries. The retrospective data segmentation within one R-R interval into ten to twenty phases is the principle of the imaging of the pulsatory or shuttle-like movement of the arteries and allows also the display of the rapid flow dynamic for example jet of the rapid bleeding or whirlpool mixing of the blood with contrast agent in cardiac atria or in aneurysms. The presented review discuss the current problems of the novel imaging method with the increased dose or limited tissue coverage, the possible troubleshoots are listed.
- MeSH
- Angiography methods MeSH
- Financing, Organized MeSH
- Humans MeSH
- Tomography, X-Ray Computed MeSH
- Check Tag
- Humans MeSH
BACKGROUND AND PURPOSE: The length of large vessel occlusion is considered a major factor for therapy in patients with ischemic stroke. We used 4D-CT angiography evaluation of middle cerebral artery occlusion in prediction of recanalization and favorable clinical outcome and after intravenous thrombolysis (IV-tPA). METHODS: In 80 patients treated with IV-tPA for acute complete middle cerebral artery/M1 occlusion determined using CT angiography and temporal maximum intensity projection, calculated from 4D-CT angiography, the length of middle cerebral artery proximal stump, occlusion in M1 or M1 and M2 segment were measured. Univariate and multivariate analyses were performed to define independent predictors of successful recanalization after 24 hours and favorable outcome after 3 months. RESULTS: The length of occlusion was measureable in all patients using temporal maximum intensity projection. Recanalization thrombolysis in myocardial infarction 2 to 3 was achieved in 37 individuals (46%). The extension to M2 segment as a category (odds ratio, 4.58; 95% confidence interval, 1.39-15.05; P=0.012) and the length of M1 segment occlusion (odds ratio, 0.82; 95% confidence interval, 0.73-0.92; P=0.0007) with an optimal cutoff value of 12 mm (sensitivity 0.67; specificity 0.71) were significant independent predictors of recanalization. Favorable outcome (modified Rankin scale 0-2) was achieved in 25 patients (31%), baseline National Institutes of Health Stroke Scale (odds ratio, 0.82; 95% confidence interval, 0.72-0.93; P=0.003) and the length of occlusion M1 in segment (odds ratio, 0.79; 95% confidence interval, 0.69-0.91; P=0.0008) with an optimal cutoff value of 11 mm (sensitivity 0.74; specificity 0.76) were significant independent predictors of favorable outcome. CONCLUSIONS: The length of middle cerebral artery occlusion is an independent predictor of successful IV-tPA treatment.
- MeSH
- Four-Dimensional Computed Tomography instrumentation methods MeSH
- Adult MeSH
- Fibrinolytic Agents administration & dosage pharmacology MeSH
- Infarction, Middle Cerebral Artery * drug therapy pathology radiography MeSH
- Middle Aged MeSH
- Humans MeSH
- Cerebral Angiography MeSH
- Cerebrovascular Circulation drug effects physiology MeSH
- Predictive Value of Tests MeSH
- Retrospective Studies MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Tissue Plasminogen Activator administration & dosage pharmacology MeSH
- Thrombolytic Therapy methods MeSH
- Treatment Outcome MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: Haynaldia villosa (H. villosa) has been recognized as a species potentially useful for wheat improvement. The availability of its genomic sequences will boost its research and application. RESULTS: In this work, the short arm of H. villosa chromosome 4V (4VS) was sorted by flow cytometry and sequenced using Illumina platform. About 170.6 Mb assembled sequences were obtained. Further analysis showed that repetitive elements accounted for about 64.6% of 4VS, while the coding fraction, which is corresponding to 1977 annotated genes, represented 1.5% of the arm. The syntenic regions of the 4VS were searched and identified on wheat group 4 chromosomes 4AL, 4BS, 4DS, Brachypodium chromosomes 1 and 4, rice chromosomes 3 and 11, and sorghum chromosomes 1, 5 and 8. Based on genome-zipper analysis, a virtual gene order comprising 735 gene loci on 4VS genome was built by referring to the Brachypodium genome, which was relatively consistent with the scaffold order determined for Ae. tauschii chromosome 4D. The homologous alleles of several cloned genes on wheat group 4 chromosomes including Rht-1 gene were identified. CONCLUSIONS: The sequences provided valuable information for mapping and positional-cloning genes located on 4VS, such as the wheat yellow mosaic virus resistance gene Wss1. The work on 4VS provided detailed insights into the genome of H. villosa, and may also serve as a model for sequencing the remaining parts of H. villosa genome.
Ultrasonografie je důležitou vyšetřovací metodou při zobrazení ledvin. Hlavní výhodou je dostupnost, neinvazivita a nízké náklady vyšetření. V současné době lze provádět 3D a 4D zobrazení, pro diagnostiku ložiskových lézí ledvin je možno použít harmonické zobrazení, jsou dostupné kontrastní látky pro ultrazvuková vyšetření, a v poslední době byla použita elastografie in vivo pro zobrazení expanzí ledvin. Probíhá intenzivní výzkum zkoumající možnosti ultrasonografie při diagnostice renálních tumorů.
Ultrasonography is important diagnostic modality in examination of kidneys. Availability, noninvasivity, low costs and relative inexpensivity are main advantages. Is possible to perform 3D and 4D imaging. Harmonic imaging can be used in imaging of renal masses and contrast agents are available for contrast-enhanced studies. Sonoelastography in the imaging of renal masses has been applied in vivo recently. There is an increasing flow of data from studies investigating the role of ultrasonography in the evaluation of renal masses.
- Keywords
- renální tumor, SonoVue, Optison,
- MeSH
- Diagnostic Techniques, Urological MeSH
- Contrast Media diagnostic use MeSH
- Humans MeSH
- Microbubbles MeSH
- Kidney Neoplasms diagnosis MeSH
- Nonlinear Dynamics MeSH
- Computer Simulation MeSH
- Signal Processing, Computer-Assisted MeSH
- Ultrasonography, Doppler methods utilization MeSH
- Ultrasonography methods utilization MeSH
- Ultrasonics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
We have studied T1 and T2 weighted MR images of thrombus from examination of patients with small abdominal aortic aneurysms in order to know whether the thrombus signal can be linked with the aortic diameter enlargement, and then could predict rupture risk of the aorta wall. Data were obtained from 16 patients with Small Abdominal Aortic Aneurysms (SAAA) who had been examined since July 2006 to January 2010 with MR Images. Several parameters were used to study the thrombus signal, such as mean, median, standard deviation, skewness and kurtosis. Each parameter was calculated for the thrombus area, and the signal in the muscle was used to normalize the mean, median and standard deviation of signal in thrombus. After then, those parameters were compared with evolution of the aortic diameter. 13 of the 16 patient with SAAA had a thrombus. Unfortunately there were no correlations between thrombus signals with the evolution of the aortic diameter (R often less then 0.3). But some parameter show links between thrombus signal and maximum diameter (mean (R=0.318)), median (R=0.318), skewness (R=0.304)) or with D maximum diameter (mean (R=0.512)). We cannot use thrombus signal alone as the parameter to predict the evolution of the aortic diameter. This study is the first step of our overall study. In the next step, we will use blood flow velocity with 3D/4D modelisation on the aortic aneurysm as a comparison parameter for predicting the rupture risk of the aortic wall. Moreover, relationship between flow data and thrombus will be studied.
BACKGROUND: Haynaldia villosa (L.) Schur (syn. Dasypyrum villosum L. Candargy, 2n = 14, genome VV) is the tertiary gene pool of wheat, and thus a potential resource of genes for wheat improvement. Among other, wheat yellow mosaic (WYM) resistance gene Wss1 and a take-all resistance gene were identified on the short arm of chromosome 4 V (4VS) of H. villosa. We had obtained introgressions on 4VS chromosome arm, with the objective of utilizing the target genes. However, monitoring these introgressions has been a daunting task because of inadequate knowledge as to H.villosa genome, as reflected by the lack of specific markers. RESULTS: This study aims to develop 4VS-specific markers by combination of chromosome sorting and next-generation sequencing. The short arm of chromosome 4VS of H.villosa was flow-sorted using a FACSVantage SE flow cytometer and sorter, and then sequenced by Illumina sequencing. The sequence of H. villosa 4VS was assembled by the software Hecate, and then was compared with the sequence assemblies of wheat chromosome arms 4AL, 4BS and 4DS and Ae. tauschii 4DS, with the objectives of identifying exon-exon junctions and localizing introns on chromosome 4VS of H. villosa. The intron length polymorphisms suitable for designing H. villosa primers were evaluated with criteria. Consequently, we designed a total of 359 intron targeting (IT) markers, among which 232 (64.62%) markers were specific for tracing the 4VS chromatin in the wheat background. CONCLUSION: The combination of chromosome sorting and next-generation sequencing to develop specific IT markers for 4VS of H. villosa has high success rate and specificity, thus being applicable for the development of chromosome-specific markers for alien chromatin in wheat breeding.
. -- Possibilities of the flow measurement in MR imaging -- systems with low magnetic fields . 11 -- ^ --4d. . . . . IB -- F i k r V. . Honz ák ová L - . Štika L. • 0|{?|? H. -- An impedance rheoangiograph end the examinet ion -- method for limb blood flow * . 80 -- Pglikán
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- MeSH
- Biomedical Engineering MeSH
- Publication type
- Abstracts MeSH
- Congress MeSH
- Collected Work MeSH
- Conspectus
- Lékařské vědy. Lékařství
- NML Fields
- biomedicínské inženýrství
Titlestad (Norway) * 462 -- * poster -- xii -- Section 4D. Wastl (Germany) 709 -- * poster -- XVI -- Estimation of Blood Flow in the Upper Gastrointestinal Tract Hebert 1145 -- Investigation and Evaluation of the Change in the Outpatients Flow before and after the Zwetsloot-Schonk 988 -- An Information Flow Analysis of a Distributed Information System for Space Medical Fukunaga: COMPUTER ANALYSIS OF THE MAXIMUM EXPIRATORY 529 FLOW VOLUME CURVE. (Japan) -- S.
IFIP world conference series on medical informatics Studies in health technology and informatics
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- MeSH
- Information Systems MeSH
- Medical Informatics MeSH
- Medicine MeSH
- Publication type
- Congress MeSH
- Collected Work MeSH
- Conspectus
- Lékařské vědy. Lékařství
- NML Fields
- lékařská informatika
