We would like to thank the Vanderbilt University Institute of Imaging Science MRI technologists David Pennell, Leslie McIntosh, and Kristen George-Durrett, and the team of Vanderbilt University Medical Center PET/CT technologists led by Martha D. Shone. This work was supported by the following grants from the NIH: NCATS/NIH UL1 RR024975, NIDDK/NIH R21DK096282, NCI/NIH R25CA136440, and NIBIB/NIH T32EB014841.

The authors declare that they have no competing financial interests or other conflicts of interests.

Il protocollo dello studio descritto è stato progettato per utilizzare sia thermoneutral e attivati ​​freddo PET / CT per automaticamente segmento depositi BAT su base oggetto specifico. Queste regioni generate automaticamente di interesse possono essere applicate a entrambe le scansioni MRI temperatura neutra e attivato freddo che sono stati co-registrate per le scansioni PET / TC dello stesso soggetto. Per quanto a nostra conoscenza, questa è la prima ricerca di eseguire sia MRI e PET / CT dopo condizioni di tem...

A causa del marcato aumento dell&#39;obesità in tutto il mondo, vi è un crescente interesse nelle aree di ricerca finalizzati alla comprensione del bilancio energetico. L&#39;obesità può portare a condizioni mediche costose e devastanti come il diabete, malattie del fegato, malattie cardiovascolari e cancro, che lo rende una significativa area di preoccupazione per la salute pubblica 1. Un settore di ricerca volta a comprendere l&#39;equilibrio di apporto energetico rispetto al dispendio energetico è lo studio del tessuto adiposo bruno o BAT. Anche se definito un tessuto adiposo, BAT si differenzia dalla più comune tessuto adiposo bianco (WAT) in molti modi 2. La funzione degli adipociti bianchi è per memorizzare trigliceridi in un unico grande vacuolo lipidico per cella, e per liberare tali trigliceridi come fonte di energia nel flusso sanguigno quando necessario. In modo molto diverso, la funzione di adipociti bruni è di produrre calore. Un meccanismo con cui questo avviene è attraverso l&#39;esposizione al freddo. Questo provoca un aumento sympathetic attività del sistema nervoso, che a sua volta attiva BAT. Quando viene attivato, adipociti bruni generano calore. Per fare ciò, si utilizzano i trigliceridi contenuti nei numerosi piccoli vacuoli lipidici per cella, e attraverso la presenza di proteine ​​di disaccoppiamento 1 (UCP1) nei mitocondri abbondante, convertire i trigliceridi a substrati metabolici senza la produzione di ATP, con conseguente perdita entropica la generazione di calore. Poiché i trigliceridi memorizzati nei piccoli vacuoli lipidici sono esaurite, adipociti riprende sia il glucosio e trigliceridi presenti nel flusso sanguigno 3. L&#39;interesse per lo studio BAT è drammaticamente aumentata negli ultimi anni grazie al suo contributo alla non-brividi termogenesi, il suo ruolo nel modulare la spesa energetica del corpo, e la potenziale relazione inversa tra BAT e obesità 3 - 9. Inoltre, recenti studi su animali indicano BAT gioca un ruolo fondamentale in trigliceridi compensazione e glucosio fROM sangue, soprattutto dopo l&#39;ingestione di un pasto ricco di grassi 10,11. Tuttavia, la maggior parte di ciò che sappiamo sulla BAT è il risultato della ricerca in piccoli mammiferi, che contengono molti depositi di BAT 4,9,12 - 15. Nonostante alcuni studi presto 16 - 18, la presenza di BAT negli esseri umani è stato ampiamente pensato a diminuire con l&#39;età fino a poco tempo in cui è stato rinnovato interesse per lo studio BAT umana. Recenti ricerche indicano che quantità relativamente piccole di BAT persistono in età adulta 19-24. Un ulteriore fattore limitante per studiare BAT è che, a parte la biopsia e colorazione istologica, il metodo inequivocabile attualmente accettato per rilevare BAT 18 F-fluorodeossiglucosio (18 F-FDG) tomografia ad emissione di positroni (PET). Scanner PET moderni sono in genere combinati con una tomografia computerizzata (CT) scanner. Quando attivato da esposizione al freddo, BAT riprende il 18 </sup&gt; radiotracciante F-FDG, che è un analogo metabolica del glucosio, e diventa visibile sulle immagini PET, rispetto al livello molto più basso di 18 F-FDG quando BAT 20,21,23,25 inattiva. Immagini TC acquisite nel corso di un esame PET su una PET-CT scanner aiutano a distinguere tra tessuti con alto 18 F-FDG, fornendo informazioni anatomiche. Questo uso dell&#39;imaging PET-CT espone il soggetto a radiazioni ionizzanti (prevalentemente da PET, sebbene la dose dalla TAC non è trascurabile), ed è quindi un metodo per il rilevamento indesiderato BAT. Anche se il numero di studi sulla BAT negli esseri umani adulti sani è in aumento, recenti studi di BAT umana sono principalmente sono limitati a retrospettiva PET-CT studi di 19,25, cadaveri umani infantili 26,27, gli adolescenti umani che sono già stati ammessi in ospedale per altri motivi 27 - 30, e alcuni studi umani adulti sani31 - 35. Una delle sfide con entrambi gli studi di bambini e di studi retrospettivi è la possibilità di risultati alterati quando si studia una popolazione di pazienti che è malato, che possono influire BAT. Inoltre, poiché il glucosio non è la fonte di combustibile preferita di BAT 36, gli studi PET possono non rilevare sempre BAT attivato, e quindi possono underrepresent la presenza di BAT. Un&#39;altra difficoltà nello studio BAT con l&#39;imaging biomedico è legata all&#39;esecuzione di segmentazione di immagini per definire i confini di depositi di tessuto. Attualmente, la segmentazione delle BAT negli studi umani si basa spesso su un certo grado di segmentazione manuale ed è quindi vulnerabile a errori di identificazione dei depositi BAT, nonché alla variabilità inter-rater. A causa di queste sfide, tecniche di mappatura spaziale affidabili in grado di distinguere BAT da distribuzioni WAT, insieme a metodi di segmentazione automatici, avrebbe fornito agli investigatori un potente nuovo aolo con cui studiare BAT. La risonanza magnetica (MRI) ha la capacità per l&#39;identificazione, la mappatura del territorio, e la quantificazione volumetrica di BAT, ea differenza di approcci di imaging esistenti ibridi PET-CT, che comprendono una dose radioattiva per il soggetto con immagini, risonanza magnetica non comporta radiazioni ionizzanti e può essere utilizzato in modo sicuro e ripetutamente. La capacità di identificare e quantificare BAT utilizzando la risonanza magnetica può avere un drammatico impatto positivo sulla endocrinologia clinica e la ricerca di nuove vie di ricerca di obesità. Grasso-acqua precedente MRI (FWMRI) studi di BAT sia nei topi e gli esseri umani dimostrano che il grasso-segnale frazione (FSF) di BAT è nel range del 40-80% di grassi, mentre WAT è superiore al 90% di grassi 15,26 , 27. Pertanto ipotizziamo che questo quantitativa FWMRI metrica, in combinazione con altre metriche MRI quantitative, può essere utilizzato in futuro lavoro per visualizzare e quantificare depositi BAT nell&#39;uomo. Ciò fornire alla comunità di ricerca con un potente strumento con cui studiare l&#39;influenza di BAT su incontratoabolism e dispendio energetico senza l&#39;uso di radiazioni ionizzanti. Il nostro gruppo di ricerca ha studiato BAT negli esseri umani adulti per gli ultimi tre anni. La nostra prima presentazione pubblica sull&#39;uso della risonanza magnetica per indagare sospetti BAT nel soggetto umano un adulto si è verificato nel mese di febbraio 2012 presso la Società Internazionale per la Risonanza Magnetica in Medicina (ISMRM) Separazione Fat-Water Workshop a Long Beach, California 37. Due mesi più tardi, il nostro gruppo ha presentato valori FSF in sospetto BAT in due adulti in occasione della riunione annuale ° 20 del ISMRM nell&#39;aprile 2012 a Melbourne, Australia 38. Un anno più tardi alla riunione annuale st 21 del ISMRM aprile 2013 a Salt Lake City, nello Utah, il protocollo descritto in questo manoscritto è stato utilizzato per la prima (al meglio delle nostre conoscenze) presentazione pubblica di MRI quantificazione della PET-confermata BAT in umano soggetti adulti 39. In particolare, abbiamo presentato le prove che dimostrano che la precedente ay sospetto BAT è stato confermato per essere BAT attivabile utilizzando sia thermoneutral attivato freddo e di imaging 18 F-FDG PET-CT. Dal 2013, la nostra coorte di adulti volontari sani, ripreso sia con MRI e PET / CT in condizioni di temperatura e attivato freddo ha ampliato a più di 20 soggetti con risultati più recentemente presentati nel mese di febbraio 2014 il workshop &quot;Esplorare il ruolo di Brown Fat in esseri umani &quot;promosso dal NIH NIDDK 40. In particolare, abbiamo riportato FWMRI FSF e R 2 * proprietà di rilassamento nelle regioni della BAT sopraclavicolare confermati da 18 F-FDG PET-CT negli esseri umani adulti, con le ROI BAT delineati utilizzando algoritmi di segmentazione automatici basata sul termoneutrale attivato freddo e PET-CT scansioni. Più di recente abbiamo presentato i risultati di mappatura della temperatura a 18 F-FDG PET-CT ha confermato BAT negli esseri umani adulti, utilizzando l&#39;avanzata FWMRI termometria 41,42. La procedura qui presentata acquisires sia MRI e 18 scansioni F-FDG PET-TC sullo stesso argomento, ognuno dopo l&#39;esposizione a entrambe le condizioni di temperatura attivati ​​freddo e. Le 18 scansioni F-FDG PET-CT temperatura neutra attivate freddo e sono usati per creare le regioni segmentati automaticamente BAT di interesse (ROI), su base oggetto specifico. Questi ROI BAT vengono poi applicati alle co-registrato risonanza magnetica per misurare le proprietà di risonanza magnetica della PET-CT confermato BAT. Una limitazione di questo protocollo è che la temperatura dell&#39;aria utilizzata quando espone soggetti a uno stimolo caldo o freddo è costante per ogni soggetto. Questa è una limitazione in quanto la temperatura alla quale ciascun soggetto vive sensazione di calore o refrigerate può essere differente. Pertanto, eseguendo una sessione di prova durante il quale la temperatura dell&#39;aria è regolata per adattarsi risposta individuale, e quindi utilizzando queste temperature durante i protocolli di temperatura neutra e fredda-attivazione, potrebbe essere possibile ottenere risposte miglioridal tessuto adiposo bruno.

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			<td height="100" style="height:100px;width:363px;">Name of Material/ Equipment</td>
			<td style="width:392px;">Company</td>
			<td style="width:375px;">Catalog Number</td>
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			<td height="38" style="height:39px;width:363px;">MRI</td>
			<td style="width:392px;">Philips</td>
			<td style="width:375px;">Achieva 3T</td>
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		<tr height="68">
			<td height="68" style="height:68px;width:363px;">MRI Torso-XL coil</td>
			<td style="width:392px;">Philips</td>
			<td style="width:375px;">Philips SENSE XL Torso coil 16-elements</td>
		</tr>
		<tr height="68">
			<td height="68" style="height:68px;width:363px;">MRI X-tend Table</td>
			<td style="width:392px;">X-Tend</td>
			<td style="width:375px;">X-tend table, Acieva 3T compatible</td>
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		<tr height="34">
			<td height="34" style="height:34px;width:363px;">X-tend armsupport</td>
			<td style="width:392px;">X-Tend</td>
			<td style="width:375px;">X-tend, accessories</td>
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			<td height="34" style="height:34px;width:363px;">X-tend fabricsling</td>
			<td style="width:392px;">X-Tend</td>
			<td style="width:375px;">X-tend, accessories</td>
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			<td height="38" style="height:39px;width:363px;">PET/CT</td>
			<td style="width:392px;">GE</td>
			<td style="width:375px;">Discovery STE</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Portable A/C Unit</td>
			<td style="width:392px;">Soleus Air</td>
			<td style="width:375px;">XL-140, 14000 BTU</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Floor fan</td>
			<td style="width:392px;">Lasko Pedestal Fan</td>
			<td style="width:375px;">2527</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Portable Heater</td>
			<td style="width:392px;">Lasko Ceramic Air</td>
			<td style="width:375px;">5536</td>
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			<td height="38" style="height:39px;width:363px;">Chair</td>
			<td style="width:392px;">Winco Lifecare Recliner</td>
			<td style="width:375px;">585</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Sublingual Thermometer</td>
			<td style="width:392px;">WelchAllyn</td>
			<td style="width:375px;">SureTemp Plus 690</td>
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		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Cold vest</td>
			<td style="width:392px;">Polar Products</td>
			<td style="width:375px;">Cool58 #PCVZ</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:39px;width:363px;">Thermal IR Camera</td>
			<td style="width:392px;">FLUKE</td>
			<td style="width:375px;">TIR-125</td>
		</tr>
	</tbody>
</table>

human brown adipose tissue depots automatically segmented by positron emission tomography/computed tomography and registered magnetic resonance images

Affidabile differenziando tessuto adiposo bruno (BAT) da altri tessuti utilizzando un metodo di imaging non invasivo è un passo importante verso lo studio BAT negli esseri umani. Rilevamento BAT è tipicamente confermata dalla captazione del tracciante radioattivo iniettato 18 F-Fluorodeoxyglucose (18 F-FDG) nei depositi tessuto adiposo, come misurato mediante tomografia a emissione di positroni / tomografia computerizzata (PET-CT) scansioni dopo esporre il soggetto a stimolo freddo . Fat-acqua separata risonanza magnetica (MRI) ha la capacità di distinguere BAT senza l&#39;uso di un tracciante radioattivo. Ad oggi, la risonanza magnetica di BAT in esseri umani adulti non è stato co-registrato con attivati ​​freddo PET-CT. Pertanto, questo protocollo utilizza 18 scansioni F-FDG PET-CT per generare automaticamente una maschera BAT, che viene poi applicata a co-registrato MRI scansioni dello stesso soggetto. Questo approccio permette di misurare le proprietà MRI quantitativi della BAT senza segmentazione manuale. Maschere BAT sono creati da due PEScansioni T-CT: dopo l&#39;esposizione per 2 ore a uno thermoneutral (TN) (24 ° C) o attivato a freddo (CA) (17 ° C) condizioni. I TN e CA PET-TC sono registrati, ed i valori di assorbimento standardizzati PET e CT Hounsfield sono utilizzati per creare una maschera che contiene solo BAT. CA e TN risonanza magnetica sono acquisite sullo stesso tema e registrate le scansioni PET-TC al fine di stabilire le proprietà MRI quantitative all&#39;interno della maschera BAT definito automaticamente. Un vantaggio di questo approccio è che la segmentazione è completamente automatizzato e si basa su metodi ampiamente accettati per l&#39;identificazione del attivata BAT (PET-CT). Le proprietà MRI quantitativi di BAT stabiliti utilizzando questo protocollo può servire come base per una sola MRI esame BAT che evita la radiazione associata alla PET-CT.

L&#39;acquisizione sia MRI e PET-TC sullo stesso argomento, e l&#39;esecuzione di co-registrazione su tutte le scansioni consente la misurazione affidabile di metriche MRI quantitativi di BAT. La Figura 1 mostra la non trasformati calda (TN) e fredda (CA) PET-TC e RM scansioni da un soggetto. Con l&#39;acquisizione sia TN e CA PET-CT dati, è possibile distinguere chiaramente i depositi BAT-attivato a freddo da parte del maggiore assorbimento 18 F-FDG. Dopo co-registrazione tutti quattro scan...

Watch this Scientific Journal Video about Human Brown Adipose Tissue Depots Automatically Segmented by Positron Emission Tomography/Computed Tomography and Registered Magnetic Resonance Images at JoVE

Human Brown Adipose Tissue Depots Automatically Segmented by Positron Emission Tomography/Computed Tomography and Registered Magnetic Resonance Images

Il metodo qui presentata utilizza 18 F-Fluorodeoxyglucose (18 F-FDG) tomografia ad emissione di positroni / tomografia computerizzata (PET-CT) e grasso-acqua separata risonanza magnetica (MRI), ciascuna scansione dopo 2 ore di esposizione a thermoneutral (24 ° C ) e freddo (17 ° C), al fine di mappare tessuto adiposo bruno (BAT) in soggetti umani adulti.

Umano Brown adipose Depositi tessuti segmentato automaticamente da Positron Emission Tomography / tomografia computerizzata e registrati Risonanza Magnetica Images

Reliably differentiating brown adipose tissue (BAT) from other tissues using a non-invasive imaging method is an important step toward studying BAT in ...

human-brown-adipose-tissue-depots-automatically-segmented-positron

Research

JoVE Journal

Medicine

12.1K Views.  Vanderbilt University.  Il metodo qui presentata utilizza 18 F-Fluorodeoxyglucose (18 F-FDG) tomografia ad emissione di positroni / tomografia computerizzata (PET-CT) e grasso-acqua separata risonanza magnetica (MRI), ciascuna scansione dopo 2 ore di esposizione a thermoneutral (24 ° C ) e freddo (17 ° C), al fine di mappare tessuto adiposo bruno (BAT) in soggetti umani adulti. 

Video: Human Brown Adipose Tissue Depots Automatically Segmented by Positron Emission Tomography/Computed Tomography and Registered Magnetic Resonance Images

Basic Surgical Techniques in the G&ouml;ttingen Minipig: Intubation, Bladder Catheterization, Femoral Vessel Catheterization, and Transcardial Perfusion

The emergence of the G&ouml;ttingen minipig in research of topics such as neuroscience, toxicology, diabetes, obesity, and experimental surgery reflects the close resemblance of these animals to human anatomy and physiology 1-6.The size of the G&ouml;ttingen minipig permits the use of surgical equipment and advanced imaging modalities similar to those used in humans 6-8. The aim of this instructional video is to increase the awareness on the value of minipigs in biomedical research, by demonstrating how to perform tracheal intubation, transurethral bladder catheterization, femoral artery and vein catheterization, as well as transcardial perfusion. 
Endotracheal Intubation should be performed whenever a minipig undergoes general anesthesia, because it maintains a patent airway, permits assisted ventilation and protects the airways from aspirates. Transurethral bladder catheterization can provide useful information about about hydration state as well as renal and cardiovascular function during long surgical procedures. Furthermore, urinary catheterization can prevent contamination of delicate medico-technical equipment and painful bladder extension which may harm the animal and unnecessarily influence the experiment due to increased vagal tone and altered physiological parameters. Arterial and venous catheterization is useful for obtaining repeated blood samples and monitoring various physiological parameters. Catheterization of femoral vessels is preferable to catheterization of the neck vessels for ease of access, when performing experiments involving frame-based stereotaxic neurosurgery and brain imaging. When performing vessel catheterization in survival studies, strict aseptic technique must be employed to avoid infections6. Transcardial perfusion is the most effective fixation method, and yields preeminent results when preparing minipig organs for histology and histochemistry2,9. For more information about anesthesia, surgery and experimental techniques in swine in general we refer to Swindle 2007. Supplementary information about premedication and induction of anesthesia, assisted ventilation, analgesia, pre- and postoperative care of G&ouml;ttingen minipigs are available via the internet at <a href="http://www.minipigs.com">http://www.minipigs.com</a>10. For extensive information about porcine anatomy we refer to Nickel et al. Vol. 1-511.

Basic Surgical Techniques in the G&amp;#246;ttingen Minipig: Intubation, Bladder Catheterization, Femoral Vessel Catheterization, and Transcardial Perfusion

The use of domestic and miniature pigs in science has increased significantly in recent years. By demonstrating how to perform intubation, transurethral bladder catheterization, femoral artery and vein catheterization, as well as transcardial perfusion, we aim to further increase the value of G&ouml;ttingen minipigs in biomedical research.

Tecniche chirurgiche di base Nella cavia Gottinga: intubazione, cateterismo vescicale, cateterizzazione nave femorale, e Perfusione Transcardial

The emergence of the G&ouml;ttingen minipig in research of topics such as neuroscience, toxicology, diabetes, obesity, and experimental surgery reflects ...

Ricerca

Medicina

Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT)

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC)1 and carotid intimal medial thickness (C-IMT)2 provide information about the burden of disease. However, despite multiple validation studies of CAC3-5, and C-IMT2,6, these modalities do not accurately assess plaque characteristics7,8, and the composition and inflammatory state of the plaque determine its stability and, therefore, the risk of clinical events9-13.
[18F]-2-fluoro-2-deoxy-D-glucose (FDG) imaging using positron-emission tomography (PET)/computed tomography (CT) has been extensively studied in oncologic metabolism14,15. Studies using animal models and immunohistochemistry in humans show that FDG-PET/CT is exquisitely sensitive for detecting macrophage activity16, an important source of cellular inflammation in vessel walls. More recently, we17,18 and others have shown that FDG-PET/CT enables highly precise, novel measurements of inflammatory activity of activity of atherosclerotic plaques in large and medium-sized arteries9,16,19,20. FDG-PET/CT studies have many advantages over other imaging modalities: 1) high contrast resolution; 2) quantification of plaque volume and metabolic activity allowing for multi-modal atherosclerotic plaque quantification; 3) dynamic, real-time, in vivo imaging; 4) minimal operator dependence. Finally, vascular inflammation detected by FDG-PET/CT has been shown to predict cardiovascular (CV) events independent of traditional risk factors21,22 and is also highly associated with overall burden of atherosclerosis23. Plaque activity by FDG-PET/CT is modulated by known beneficial CV interventions such as short term (12 week) statin therapy24 as well as longer term therapeutic lifestyle changes (16 months)25.
The current methodology for quantification of FDG uptake in atherosclerotic plaque involves measurement of the standardized uptake value (SUV) of an artery of interest and of the venous blood pool in order to calculate a target to background ratio (TBR), which is calculated by dividing the arterial SUV by the venous blood pool SUV. This method has shown to represent a stable, reproducible phenotype over time, has a high sensitivity for detection of vascular inflammation, and also has high inter-and intra-reader reliability26. Here we present our methodology for patient preparation, image acquisition, and quantification of atherosclerotic plaque activity and vascular inflammation using SUV, TBR, and a global parameter called the metabolic volumetric product (MVP). These approaches may be applied to assess vascular inflammation in various study samples of interest in a consistent fashion as we have shown in several prior publications.9,20,27,28

Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography FDG-PET/CT

There is great need to identify atherosclerosis non-invasively, and here we demonstrate how FDG-PET/CT can be used to detect and quantify atherosclerotic plaque activity and vascular inflammation.

Quantificazione di attività placca aterosclerotica e l&#39;infiammazione vascolare utilizzando [18-F] Fluorodeoxyglucose Positron Emission Tomography / Computed Tomography (FDG-PET/TC)

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC)1 and carotid intimal medial thickness (C-IMT)2 ...

Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG

Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to return to normal in a large majority of patients2, which is mainly due to current lack of clinical treatment for acute stroke. This necessitates understanding the physiological effects of cerebral ischemia on brain tissue over time and is a major area of active research. Towards this end, experimental progress has been made using rats as a preclinical model for stroke, particularly, using non-invasive methods such as 18F-fluorodeoxyglucose (FDG) coupled with Positron Emission Tomography (PET) imaging3,10,17. Here we present a strategy for inducing cerebral ischemia in rats by middle cerebral artery occlusion (MCAO) that mimics focal cerebral ischemia in humans, and imaging its effects over 24 hr using FDG-PET coupled with X-ray computed tomography (CT) with an Albira PET-CT instrument. A VOI template atlas was subsequently fused to the cerebral rat data to enable a unbiased analysis of the brain and its sub-regions4. In addition, a method for 3D visualization of the FDG-PET-CT time course is presented. In summary, we present a detailed protocol for initiating, quantifying, and visualizing an induced ischemic stroke event in a living Sprague-Dawley rat in three dimensions using FDG-PET.

Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG

Brain damage resulting from cerebral ischemia may be non-invasively imaged and studied in rats using pre-clinical positron emission tomography coupled with the injectable radioactive probe, 18F-fluorodeoxyglucose. Further, the use of modern software tools that include volume of interest (VOI) brain templates dramatically increase the quantitative information gleaned from these studies.

Imaging non invasiva e analisi di ischemia cerebrale in ratti Living Utilizzando Positron Emission Tomography con<sup&gt; 18</sup&gt; F-FDG

Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to ...

Cerenkov Luminescence Imaging of Interscapular Brown Adipose Tissue

Brown adipose tissue (BAT), widely known as a &#8220;good fat&#8221; plays pivotal roles for thermogenesis in mammals. This special tissue is closely related to metabolism and energy expenditure, and its dysfunction is one important contributor for obesity and diabetes. Contrary to previous belief, recent PET/CT imaging studies indicated the BAT depots are still present in human adults. PET imaging clearly shows that BAT has considerably high uptake of 18F-FDG under certain conditions. In this video report, we demonstrate that Cerenkov luminescence imaging (CLI) with 18F-FDG can be used to optically image BAT in small animals. BAT activation is observed after intraperitoneal injection of norepinephrine (NE) and cold treatment, and depression of BAT is induced by long anesthesia. Using multiple-filter Cerenkov luminescence imaging, spectral unmixing and 3D imaging reconstruction are demonstrated. Our results suggest that CLI with 18F-FDG is a practical technique for imaging BAT in small animals, and this technique can be used as a cheap, fast, and alternative imaging tool for BAT research.

In this video report, we show the application of Cerenkov Luminescence Imaging (CLI) for interscapular brown adipose tissue in mice under activated and depressed conditions.

Cerenkov Luminescenza Imaging di interscapolare Brown Tessuto adiposo

Brown adipose tissue (BAT), widely known as a &#8220;good fat&#8221; plays pivotal roles for thermogenesis in mammals. This special tissue is closely ...

Localization, Identification, and Excision of Murine Adipose Depots

Obesity has increased dramatically in the last few decades and affects over one third of the adult US population. The economic effect of obesity in 2005 reached a staggering sum of $190.2 billion in direct medical costs alone. Obesity is a major risk factor for a wide host of diseases. Historically, little was known regarding adipose and its major and essential functions in the body. Brown and white adipose are the two main types of adipose but current literature has identified a new type of fat called brite or beige adipose. Research has shown that adipose depots have specific metabolic profiles and certain depots allow for a propensity for obesity and other related disorders. The goal of this protocol is to provide researchers the capacity to identify and excise adipose depots that will allow for the analysis of different factorial effects on adipose; as well as the beneficial or detrimental role adipose plays in disease and overall health. Isolation and excision of adipose depots allows investigators to look at gross morphological changes as well as histological changes. The adipose isolated can also be used for molecular studies to evaluate transcriptional and translational change or for in vitro experimentation to discover targets of interest and mechanisms of action. This technique is superior to other published techniques due to the design allowing for isolation of multiple depots with simplicity and minimal contamination.

Due to the drastic and negative connection between obesity and other comorbidities, research on the role adipose plays in disease and overall health is warranted. We present a protocol for the isolation and excision of adipose depots allowing for the study of adipose using in situ and in vitro methods.

Localizzazione, identificazione, e l&#39;escissione dei Depositi Murine adipose

Obesity has increased dramatically in the last few decades and affects over one third of the adult US population. The economic effect of obesity in 2005 ...

Encapsulation Thermogenic Preadipocytes for Transplantation into Adipose Tissue Depots

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular weight metabolites in tissues of the treated host to achieve long-term survival. The semipermeable membrane allows engrafted encapsulated cells to avoid rejection by the immune system. The encapsulation procedure was designed to enable a controlled release of bioactive compounds, such as insulin, other hormones, and cytokines. Here we describe a method for encapsulation of catabolic cells, which consume lipids for heat production and energy dissipation (thermogenesis) in the intra-abdominal adipose tissue of obese mice. Encapsulation of thermogenic catabolic cells may be potentially applicable to the prevention and treatment of obesity and type 2 diabetes. Another potential application of catabolic cells may include detoxification from alcohols or other toxic metabolites and environmental pollutants.

Here, we present a protocol for encapsulation of catabolic cells, which consume lipids for heat production in intra-abdominal adipose tissue and increase energy dissipation in obese mice.

Incapsulamento termogenico preadipocytes al trapianto nel tessuto adiposo Depositi tessuti

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular ...

Assessment of Human Adipose Tissue Microvascular Function Using Videomicroscopy

While obesity is closely linked to the development of metabolic and cardiovascular disease, little is known about mechanisms that govern these processes. It is hypothesized that pro-atherogenic mediators released from fat tissues particularly in association with central/visceral adiposity may promote pathogenic vascular changes locally and systemically, and the notion that cardiovascular disease may be the consequence of adipose tissue dysfunction continues to evolve. Here, we describe a unique method of videomicroscopy that involves analysis of vasodilator and vasoconstrictor responses of intact small human arterioles removed from the adipose depot of living human subjects. Videomicroscopy is used to examine functional properties of isolated microvessels in response to pharmacological or physiological stimuli using a pressured system that mimics in vivo conditions. The technique is a useful approach to gain understanding of the pathophysiology and molecular mechanisms that contribute to vascular dysfunction locally within the adipose tissue milieu. Moreover, abnormalities in the adipose tissue microvasculature have also been linked with systemic diseases. We applied this technique to examine depot-specific vascular responses in obese subjects. We assessed endothelium-dependent vasodilation to both increased flow and acetylcholine in adipose arterioles (50 - 350 &#181;m internal diameter, 2 - 3 mm in length) isolated from two different adipose depots during bariatric surgery from the same individual. We demonstrated that arterioles from visceral fat exhibit impaired endothelium-dependent vasodilation compared to vessels isolated from the subcutaneous depot. The findings suggest that the visceral microenvironment is associated with vascular endothelial dysfunction which may be relevant to clinical observation linking increased visceral adiposity to systemic disease mechanisms. The videomicroscopy technique can be used to examine vascular phenotypes from different fat depots as well as compare findings across individuals with different degrees of obesity and metabolic dysfunction. The method can also be used to examine vascular responses longitudinally in response to clinical interventions.

Videomicroscopy systems are used to examine functional properties of isolated adipose tissue arterioles in response to physiological and pharmacological stimuli. This technique can be used to examine microvascular phenotypes in different adipose tissue domains in obese humans.

Valutazione della funzione microvascolare di tessuto adiposo umano mediante videomicroscopia

While obesity is closely linked to the development of metabolic and cardiovascular disease, little is known about mechanisms that govern these processes. ...

Characterization of Immune Cells in Human Adipose Tissue by Using Flow Cytometry

Infiltration of immune cells in the subcutaneous and visceral adipose tissue (AT) deposits leads to a low-grade inflammation contributing to the development of obesity-associated complications such as type 2 diabetes. To quantitatively and qualitatively investigate the immune cell subsets in human AT deposits, we have developed a flow cytometry approach. The stromal vascular fraction (SVF), containing the immune cells, is isolated from subcutaneous and visceral AT biopsies by collagenase digestion. Adipocytes are removed after centrifugation. The SVF cells are stained for multiple membrane-bound markers selected to differentiate between immune cell subsets and analyzed using flow cytometry. As a result of this approach, pro- and anti-inflammatory macrophage subsets, dendritic cells (DCs), B-cells, CD4+ and CD8+ T-cells, and NK cells can be detected and quantified. This method gives detailed information about immune cells in AT and the amount of each specific subset. Since there are numerous fluorescent antibodies available, our flow cytometry approach can be adjusted to measure various other cellular and intracellular markers of interest.

This article describes a method to analyze immune cell content of adipose tissue by isolation of immune cells from adipose tissue and subsequent analysis using flow cytometry.

Caratterizzazione di cellule immunitarie nel tessuto adiposo umano mediante citometria a flusso

Infiltration of immune cells in the subcutaneous and visceral adipose tissue (AT) deposits leads to a low-grade inflammation contributing to the ...

Whole Body and Regional Quantification of Active Human Brown Adipose Tissue Using 18F-FDG PET/CT

In endothermic animals, brown adipose tissue (BAT) is activated to produce heat for defending body temperature in response to cold. BAT&#39;s ability to expend energy has made it a potential target for novel therapies to ameliorate obesity and associated metabolic disorders in humans. Though this tissue has been well studied in small animals, BAT&#39;s thermogenic capacity in humans remains largely unknown due to the difficulties of measuring its volume, activity, and distribution. Identifying and quantifying active human BAT is commonly performed using 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography and computed tomography (PET/CT) scans following cold-exposure or pharmacological activation. Here we describe a detailed image-analysis approach to quantify total-body human BAT from 18F-FDG PET/CT scans using an open-source software. We demonstrate the drawing of user-specified regions of interest to identify metabolically active adipose tissue while avoiding common non-BAT tissues, to measure BAT volume and activity, and to further characterize its anatomical distribution. Although this rigorous approach is time-consuming, we believe it will ultimately provide a foundation to develop future automated BAT quantification algorithms.

Whole Body and Regional Quantification of Active Human Brown Adipose Tissue Using 18F-FDG PET/CT

Using free, open-source software, we have developed an analytical approach to quantify total and regional brown adipose tissue (BAT) volume and metabolic activity of BAT using 18F-FDG PET/CT.

Tutto il corpo e quantificazione regionale dell'essere umano attivo marrone tessuto adiposo con 18F-FDG PET/CT

In endothermic animals, brown adipose tissue (BAT) is activated to produce heat for defending body temperature in response to cold. BAT&#39;s ability to ...

Continuous Blood Sampling in Small Animal Positron Emission Tomography/Computed Tomography Enables the Measurement of the Arterial Input Function

For quantitative analysis and bio-kinetic modeling of positron emission tomography/computed tomography (PET/CT) data, the determination of the temporal blood time-activity concentration also known as arterial input function (AIF) is a key point, especially for the characterization of animal disease models and the introduction of newly developed radiotracers. The knowledge of radiotracer availability in the blood helps to interpret PET/CT-derived data of tissue activity. For this purpose, online blood sampling during the PET/CT imaging is advisable to measure the AIF. In contrast to manual blood sampling and image-derived approaches, continuous online blood sampling has several advantages. Besides the minimized blood loss, there is an improved resolution and a superior accuracy for the blood activity measurement. However, the major drawback of online blood sampling is the costly and time-consuming preparation to catheterize the femoral vessels of the animal. Here, we describe an easy and complete workflow for catheterization and continuous blood sampling during small animal PET/CT imaging and compared it to manual blood sampling and an image-derived approach. Using this highly-standardized workflow, the determination of the fluorodeoxyglucose ([18F]FDG) AIF is demonstrated. Further, this procedure can be applied to any radiotracer in combination with different animal models to create fundamental knowledge of tracer kinetic and model characteristics. This allows a more precise evaluation of the behavior of pharmaceuticals, both for diagnostic and therapeutic approaches in the preclinical research of oncological, neurodegenerative and myocardial diseases.

Here a protocol for continuous blood sampling during PET/CT imaging of rats to measure the arterial input function (AIF) is described. The catheterization, the calibration and setup of the system and the data analysis of the blood radioactivity are demonstrated. The generated data provide input parameters for subsequent bio-kinetic modeling.

Il campionamento continuo del sangue nella tomografia a emissione di positroni di piccole dimensioni/tomografia computerizzata consente la misurazione della funzione di input arteriosa

For quantitative analysis and bio-kinetic modeling of positron emission tomography/computed tomography (PET/CT) data, the determination of the temporal ...