Vasa vasorum of the coronary arteries in an animal heart model

Vasa vasorum koronárních tepen je systém drobných cév, které vyživují stěnu věnčitých tepen. V poslední době je vasa vasorum připisován význam v patogenezi aterosklerózy, nekrózy tunica media, či v excesivním hojení intimy po zavádění stentů. Systém vasa vasorum je detailně popsán na patologicky změněných srdcích, nicméně studií, které by se zabývaly detailním popisem na zdravém lidském srdci nebo na jeho animálním modelu je minimum. Cílem dizertační práce bylo popsat strukturu a původ vasa vasorum koronárních tepen na animálním modelu srdce prasete, popsat historii termínu vasa vasorum a případně popsat vedlejší nálezy na zkoumaných vzorcích. V práci bylo dohromady použito 36 zdravých prasečích srdcí. Část z nich byla přes ústí koronárních tepen nastříknuta tuší a následně histologicky zpracována, další srdce byla rovnou fixována in toto ve formolu a histologicky zpracována, zbylá část srdcí byla nastříknuta přes ústí koronárních tepen pryskyřicí mercox a poté byly vytvořeny korozivní preparáty koronárních tepen. Tyto vzorky se vyhodnocovaly pomocí skenovacího elektronového mikroskopu. Histologické zpracování vzorků spočívalo v barvení Hematoxylinem Eosinem, Weigert van Giessonem a modrým trichromem. Vzniklé preparáty byly prohlédnuty pomocí světelného mikroskopu. Ve vzorcích byly popsány pouze...The vasa vasorum of the coronary arteries is a system of tiny vessels that nourish the wall of the coronary arteries. Recently, the vasa vasorum has been attributed importance in the pathogenesis of atherosclerosis, necrosis of the tunica media, or in excessive healing of the intima after stenting. The vasa vasorum system is described in detail on pathologically altered hearts, however, studies that would deal with a detailed description on a healthy human heart or on its animal model are minimal. The aim of the dissertation was to describe the structure and origin of the vasa vasorum of the coronary arteries on an animal model of the heart of a pig, to describe the history of the term vasa vasorum and possibly to describe secondary findings on the examined samples. A total of 36 healthy pig hearts were used in the study. Part of them was injected with India ink through the ostium of the coronary arteries and subsequently histologically processed, other hearts were directly fixed in toto in formalin and histologically processed, the remaining part of the hearts was injected through the ostium of the coronary arteries with mercox resin and then corrosive casts of the coronary arteries were created. These samples were evaluated using a scanning electron microscope. Histological processing of the...Ústav anatomie 3. LF UKDepartment of Anatomy 3FM CU3. lékařská fakultaThird Faculty of Medicin

Imaging of Soft Tissues in Micro-CT

Rentgenové snímkování je neinvazivní zobrazovací technika pro zobrazení vnitřní struktury zkoumaného objektu. V posledních letech získává na popularitě zobrazování biologických vzorků v mikro-CT. Nevýhodou této techniky je snížená schopnost zobrazovat měkké tkáně jako jsou například svaly, tuková tkáň nebo nervová tkáň, pro jejich nízký vnitřní kontrast. Cílem této práce bylo upravit komerční mikro-CT MARS, tak aby bylo schopné kvalitně zobrazovat měkké tkáně a vytvořit protokol jednoduché a levné fixace ex-vivo měkkých tkání pro zobrazování v mikro-CT. V práci bylo použito modifikované mikro-CT MARS osazené photon counting detektorem Timepix Quad s rozlišením 30µm. Mikro-CT bylo následně otestováno na fantomu i reálných měkkých tkáních. Pro snímání ex-vivo měkkých tkání v mikro-CT byla vyvinuta etanolová metoda fixace. Srdce a plíce laboratorních myší byly fixovány buď v 97% etanolu, 50% etanolu nebo ve vzestupné řadě koncentrací etanolu. Vzorky byly snímané buď po 72 hodinách, 168 hodinách, nebo po 336 hodinách. Výsledné snímky byly porovnány navzájem a se snímky nativních vzorků. Dále byla tato metoda fixace vyzkoušena na zdravých mozcích laboratorních myší za účelem zhodnocení přínosu zobrazování mozku v mikro-CT ve výzkumu centrálního nervového systému. Modifikované mikro-CT bylo úspěšně...X-ray radiography is a noninvasive imaging technique for a visualization of internal structures of investigated samples. In past years, imaging of biological samples in a micro-CT is gaining in popularity. The disadvantage of this technology is a low ability to display soft tissues like muscles, fat tissue or nerves due to their low intrinsic contrast. The aim of this study was to modify a conventional micro-CT MARS in order to improve the scanning of the soft tissues and to create a protocol for simple and cheap fixation of ex-vivo soft tissues for micro-CT scanning. In the study, a modified micro-CT MARS was used together with a photon-counting detector Timepix Quad with the resolution 30µm. The micro-CT was afterward tested on the phantom and also on the real soft tissues. For scanning soft tissues in the micro-CT, the ethanol fixation method was invented. Hearts and lungs from laboratory mice were either fixated in 97%, 50% ethanol solution or in a series of ascending ethanol concentrations. Images were acquired after 72, 168 and 336 hours. The resulting images were compared among themselves and with the native specimens. This fixation method was also used in scanning healthy mice brains in order to evaluate the contribution of displaying of a brain in a micro-CT in the research of the central...Ústav lékařské biofyziky a lékařské informatiky 3. LF UKDepartment of Medical Biophysics and Informatics 3FM CU3. lékařská fakultaThird Faculty of Medicin

Vasa vasorum of the coronary arteries in an animal heart model

The vasa vasorum of the coronary arteries is a system of tiny vessels that nourish the wall of the coronary arteries. Recently, the vasa vasorum has been attributed importance in the pathogenesis of atherosclerosis, necrosis of the tunica media, or in excessive healing of the intima after stenting. The vasa vasorum system is described in detail on pathologically altered hearts, however, studies that would deal with a detailed description on a healthy human heart or on its animal model are minimal. The aim of the dissertation was to describe the structure and origin of the vasa vasorum of the coronary arteries on an animal model of the heart of a pig, to describe the history of the term vasa vasorum and possibly to describe secondary findings on the examined samples. A total of 36 healthy pig hearts were used in the study. Part of them was injected with India ink through the ostium of the coronary arteries and subsequently histologically processed, other hearts were directly fixed in toto in formalin and histologically processed, the remaining part of the hearts was injected through the ostium of the coronary arteries with mercox resin and then corrosive casts of the coronary arteries were created. These samples were evaluated using a scanning electron microscope. Histological processing of the..

Imaging of Soft Tissues in Micro-CT

X-ray radiography is a noninvasive imaging technique for a visualization of internal structures of investigated samples. In past years, imaging of biological samples in a micro-CT is gaining in popularity. The disadvantage of this technology is a low ability to display soft tissues like muscles, fat tissue or nerves due to their low intrinsic contrast. The aim of this study was to modify a conventional micro-CT MARS in order to improve the scanning of the soft tissues and to create a protocol for simple and cheap fixation of ex-vivo soft tissues for micro-CT scanning. In the study, a modified micro-CT MARS was used together with a photon-counting detector Timepix Quad with the resolution 30µm. The micro-CT was afterward tested on the phantom and also on the real soft tissues. For scanning soft tissues in the micro-CT, the ethanol fixation method was invented. Hearts and lungs from laboratory mice were either fixated in 97%, 50% ethanol solution or in a series of ascending ethanol concentrations. Images were acquired after 72, 168 and 336 hours. The resulting images were compared among themselves and with the native specimens. This fixation method was also used in scanning healthy mice brains in order to evaluate the contribution of displaying of a brain in a micro-CT in the research of the central..

Stable Arterial Perforators Mapping in Lower Leg Using Color-coded Doppler Sonography, Acoustic Doppler and Thermal Imaging Camera in Patients Undergoing Digital Subtraction Arteriography

Background: Chronic defects in the lower leg present significant challenges in plastic surgery due to their diverse etiologies and association with impaired peripheral circulation. This study describes the localization of stable perforators and assesses their changing velocities after digital subtraction angiography (DSA). Methods: 10 patients with lower extremity defects requiring DSA, had undergone examinations applying standard methods. The localization of 40 stable perforators originating from three main arteries in crura was performed before and after angiography. Where stenoses or occlusions were observed, percutaneous transluminal angioplasty (PTA) was conducted, and changes in the perforator velocities following reperfusion were measured. Results: Angiographic abnormalities were observed in all cases. Prior to PTA, acoustic Dopplers detected 37 out of 40 perforators (90%), while color-coded sonography detected 35 out of 40 perforators (87.5%). After PTA, these numbers increased to 38 out of 40 (95%) and 37 out of 40 (92.5%) respectively. The mean flow characteristics included the peak systolic velocities (PSV) of 21.9 and 27.2, end-diastolic velocities (EDV) of 9.4 and 11.4 respectively. Post-intervention 16 micro vessels exhibited enlarged lumen diameters ranging from 1 to 3 mm, resulting in increased perfusion values for PSV in 85.2% (21.9/27.2) and EDV in 88.2% (9.4/11.4) of the patients. However, 2 perforators showed decreases in flow velocity after PTA. Conclusion: In most patients with chronic lower leg wounds and other comorbidities, adequate perforators for reconstruction can be identified by using conventional methods. PTA interventions positively impact blood flow in perforators, although they are not necessarily required prior to reconstruction

Hippocampal Spatial Position Evaluation on MRI for Research and Clinical Practice

<div><p>In clinical practice as well as in many volumetric studies we use different reorientations of the brain position towards x and y axis on the magnetic resonance imaging (MRI) scans. In order to find out whether it has an overall effect on the resulting 2D data, manual hippocampal area measurements and rotation variability of the brain (in two reoriented axes) and the skull were performed in 23 Alzheimer's disease patients and 31 healthy controls. After the MRI scanning, <i>native brain scans</i> (nat) were reoriented into the two different artificial planes (<i>anterior commissure – posterior commissure</i> axis (AC-PC) and <i>hippocampal horizontal long axis</i> (hipp)). Hippocampal area and temporal horn of the lateral ventricle was measured manually using freeware Image J program. We found that 1) hippocampal area of nat images is larger compared to hipp images, area of the nat images is equal to the AC-PC images and area of the hipp images is smaller compared to AC-PC images, 2) hippocampal area together with the area of the temporal horn for nat images is larger compared to hipp images, area of the hipp images is smaller compared to the AC-PC images and area of the nat images is smaller compared to the AC-PC images. The conclusion is that the measured area of the hippocampus in the native MRI is almost the same as the area of MRI reoriented only into the AC-PC axis. Therefore, when performing 2D area studies of the hippocampus or in the clinical practice we recommend usage of not-reoriented MRI images or to reorient them into the AC-PC axis. Surprising finding was that rotation of both AC-PC and hipp line towards x-axis among patients varies up to 35° and the same is true for the skull rotation so that it is not only a matter of the brain position.</p></div

Relationship between brain and skull rotation.

<p>The brain rotation in AC-PC axis and the skull rotation (Frankfurt plane) exhibit a similar degree of variability (- counter clockwise or dorsal). AC-PC axis, Mean  = -8.57°, SE = 9.2°. Frankfurt (auriculo-orbital) plane, Mean  = −16.3°, SE = 8.02°.</p

Brain rotation variability of AC-PC vs nat on MRI.

<p>The extent of the brain rotation in AC-PC vs nat is shown in decimal degrees on x-axis (– counter clockwise and + clockwise rotation) (p<0.05).</p

a,b,c Examples of the sagittal view of the right hippocampus on the MRI in one native and two reoriented axis.

<p>MRI sections were selected according to the best visibility of the of the hippocampus on the sagittal sections (its long or dorsoventral axis), a) position of the hippocampus on the “native” MRI scan, b) reorientation of the “native” MRI scan into the hipo-axis axis (where long axis of the hippocampus is parallel to the horizontal axis), c) reorientation of the “native” MRI scan into the CA-CP. White lines represent long axis of the hippocampus.</p

Example of manual anatomical delineation of the hippocampus (white line with grey area inside) and temporal horn of the lateral ventricle (white line with black area inside) on the left and right side.

<p>Coronal sections of the MRI are located at the transition from the <i>alveus</i> of the hippocampus into the hippocampal body.</p