Micro-computed tomography (micro-CT) is an exceptional imaging modality which is limited in visualizing soft biological tissues that need pre-examination contrasting steps, which can cause serious deformation to sizeable specimens like engorged ticks. The aim of this study was to develop a new technique to bypass these limitations and allow the imaging of fed ticks in their natural state. To accomplish this, adult Ixodes ricinus females were allowed to engorge in vitro on blood supplemented with PEGylated gold nanoparticles (PEG-AuNPs). In total, 73/120 females divided into 6 groups engorged on blood enriched with 0.07-2.16 mg PEG-AuNPs per ml of blood. No toxic effect was observed for any of the tested groups compared to the control group, in which 12/20 females engorged on clear blood. The ticks were scanned on a Bruker micro-CT SkyScan 1276. The mean radiodensity of the examined ticks exceeded 0 Hounsfield Units only in the case of the two groups with the highest concentration. The best contrast was observed in ticks engorged on blood with the highest tested concentration of 2.16 mg/mL PEG-AuNPs. In these ticks, the midgut and rectal sac were clearly visible. Also, the midgut lumen volume was computed from segmented image data. The reduction in midgut volume was documented during the egg development process. According to this pilot study, micro-CT of ticks engorged on blood supplemented with contrasting agents in vitro may reveal additional information regarding the engorged ticks' anatomy.
- MeSH
- klíště * MeSH
- kovové nanočástice * MeSH
- krev MeSH
- rentgenová mikrotomografie metody MeSH
- stravovací zvyklosti MeSH
- zlato * MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Laser speckle contrast imaging (LSCI) is a noninvasive method, which uses scattered light to estimate the flow of a fluid containing scatterers. Thus, it can be especially used to estimate blood flow. Laser light is randomly scattered on the tissue and this refracted light interfere with reflected light, giving birth to laser speckle noise. As the light scatters on moving red blood cells, the speckle pattern is blurred due to the exposition time. This blurring is a function of velocity which can be estimated from the degree of blur, termed as speckle contrast. Therefore, blood cells act like contrast agent, outlining blood vessels. The simple setup, unnecessary contrast agent and unharming nature are making LSCI a popular tool for studying blood flow dynamics and vascular structure. This paper presents a new, simple experimental setup and image processing methods to treat laser speckle images aiming to estimate relative blood flow and vascular structure.
Dynamic contrast-enhanced ultrasound (DCE-US) imaging is a promising diagnostic method, which enables the evaluation of tissue perfusion via different parameters. The mean transit time and time-to-peak parameters are the main time parameters and their values depend on the model used for the approximation of the noisy perfusion curves. In this paper, we described a new comparison of different perfusion models using a tissue mimicking phantom. The following models were compared: log-normal, lagged, Erlang, Gamma and the local density random walk model. We discovered that the mean-square error is not the best criterion for model evaluation. More important is the comparison between the estimated time perfusion parameters and the physical parameters of the developed tissue mimicking phantom. Based on the statistical analysis, we can suggest that for the DCE-US perfusion analysis more models should be used, excluding the log-normal model, which gives the highest error of mean transit time value.
- MeSH
- algoritmy * MeSH
- biologické modely * MeSH
- fantomy radiodiagnostické MeSH
- indikátorové diluční techniky * MeSH
- interpretace obrazu počítačem metody MeSH
- kontrastní látky analýza farmakokinetika MeSH
- lidé MeSH
- počítačová simulace MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- ultrasonografie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- MeSH
- kontrastní látky * MeSH
- lidé MeSH
- matematika MeSH
- modely nemocí na zvířatech MeSH
- perfuzní zobrazování * MeSH
- prasata MeSH
- ultrasonografie * metody MeSH
- výzkum MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Klíčová slova
- registrace ultrazvukových sekvencí,
- MeSH
- kontrastní látky MeSH
- lidé MeSH
- perfuzní zobrazování MeSH
- počítačové zpracování obrazu * MeSH
- ultrasonografie * metody využití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem 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
