In-Vivo Synchrotron Imaging Of Regional Ventilation And Blood Volume After Methacholine Provocation In Rabbit

2012 ◽  
Author(s):  
Liisa Porra ◽  
Sam Bayat ◽  
Satu Strengell ◽  
Pekka Suortti ◽  
Anssi RA Sovijarvi
Keyword(s):  
Blood Volume ◽  
Regional Ventilation ◽  
Synchrotron Imaging ◽  
Methacholine Provocation

Hemophilic Bledding Evaluated by Blood Pool Scanning

1981 ◽  
Vol 45 (03) ◽  
pp. 208-210 ◽  
Author(s):  
D Green ◽  
S M Spies ◽  
N A Rana ◽  
J W Milgram ◽  
R Mintzer
Keyword(s):  
Blood Volume ◽  
Blood Pool ◽  
Invasive Technique ◽  
Scintillation Camera ◽  
Knee Prostheses ◽  
Hemophilic Patient ◽  
Chronic Arthropathy ◽  
Image Density ◽  
Regional Blood Volume

SummaryThe technique of blood pool scanning was used to examine 15 hemophilic subjects. Employing an in vivo method for erythrocyte labeling with Technetium-99 m, a dynamic perfusion sequence is obtained using a scintillation camera positioned over the area to be examined. This demonstrates the vascularity of the tissue. Subsequently, equilibrium blood pool images of the area are obtained and analyzed with a densitometer to assess relative regional blood volume. In patients who were not bleeding but had chronic arthropathy, vascularity was not increased, and the blood volume of comparable joints was similar. By contrast, marked increases in vascularity and image density were observed in studies of acutely bleeding joints. Chronic hemarthroses were associated with persistent, but less marked increases in joint perfusion. Transient increases in joint vascularity were demonstrated after insertion of knee prostheses. In a patient with a thigh hematoma, the dimensions of the hemorrhage were clearly delineated. Since only a tracer dose of nuclide is infused intravenously, there are no allergic reactions or other side effects of the procedure. Blood pool scanning is a safe, non-invasive technique that augments clinical and radiographic evaluations, and provides a new dimension in the assessment of the hemophilic patient.

Non-invasive in vivo infrared laser spectroscopy to analyse endogenous oxy-haemoglobin, deoxy-haemoglobin, and blood volume in the rat CNS

2005 ◽  
Vol 145 (1-2) ◽  
pp. 11-22 ◽  
Author(s):  
Francesco Crespi ◽  
Andrea Bandera ◽  
Maurizio Donini ◽  
Christian Heidbreder ◽  
Luigi Rovati
Keyword(s):  
Blood Volume ◽  
Laser Spectroscopy ◽  
Infrared Laser ◽  
Non Invasive ◽  
Infrared Laser Spectroscopy ◽  
Rat Cns

Cerebral oxygen availability by NIR spectroscopy during transient hypoxia in humans

1990 ◽  
Vol 69 (3) ◽  
pp. 907-913 ◽  
Author(s):  
N. B. Hampson ◽  
E. M. Camporesi ◽  
B. W. Stolp ◽  
R. E. Moon ◽  
J. E. Shook ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Volume ◽  
Near Infrared ◽  
Cerebral Blood Volume ◽  
Minute Ventilation ◽  
Nir Spectroscopy ◽  
Redox Status ◽  
Total Blood ◽  
Arterial Ph

The effects of mild hypoxia on brain oxyhemoglobin, cytochrome a,a3 redox status, and cerebral blood volume were studied using near-infrared spectroscopy in eight healthy volunteers. Incremental hypoxia reaching 70% arterial O2 saturation was produced in normocapnia [end-tidal PCO2 (PETCO2) 36.9 +/- 2.6 to 34.9 +/- 3.4 Torr] or hypocapnia (PETCO2 32.8 +/- 0.6 to 23.7 +/- 0.6 Torr) by an 8-min rebreathing technique and regulation of inspired CO2. Normocapnic hypoxia was characterized by progressive reductions in arterial PO2 (PaO2, 89.1 +/- 3.5 to 34.1 +/- 0.1 Torr) with stable PETCO2, arterial PCO2 (PaCO2), and arterial pH and resulted in increases in heart rate (35%) systolic blood pressure (14%), and minute ventilation (5-fold). Hypocapnic hypoxia resulted in progressively decreasing PaO2 (100.2 +/- 3.6 to 28.9 +/- 0.1 Torr), with progressive reduction in PaCO2 (39.0 +/- 1.6 to 27.3 +/- 1.9 Torr), and an increase in arterial pH (7.41 +/- 0.02 to 7.53 +/- 0.03), heart rate (61%), and ventilation (3-fold). In the brain, hypoxia resulted in a steady decline of cerebral oxyhemoglobin content and a decrease in oxidized cytochrome a,a3. Significantly greater loss of oxidized cytochrome a,a3 occurred for a given decrease in oxyhemoglobin during hypocapnic hypoxia relative to normocapnic hypoxia. Total blood volume response during hypoxia also was significantly attenuated by hypocapnia, because the increase in volume was only half that of normocapnic subjects. We conclude that cytochrome a,a3 oxidation level in vivo decreases at mild levels of hypoxia. PaCO is an important determinant of brain oxygenation, because it modulates ventilatory, cardiovascular, and cerebral O2 delivery responses to hypoxia.

scholarly journals Quantification of vascular networks in photoacoustic mesoscopy

2021 ◽  
Author(s):  
Emma L Brown ◽  
Thierry L Lefebvre ◽  
Paul W Sweeney ◽  
Bernadette Stolz ◽  
Janek Gröhl ◽  
...  
Keyword(s):  
Blood Volume ◽  
Network Structure ◽  
In Silico ◽  
Ex Vivo ◽  
Image Filtering ◽  
Vascular Networks ◽  
Ground Truth Data ◽  
Rule Based ◽  
Segmentation Methods

Mesoscopic photoacoustic imaging (PAI) enables non-invasive visualisation of tumour vasculature and has the potential to assess prognosis and therapeutic response. Currently, evaluating vasculature using mesoscopic PAI involves visual or semi-quantitative 2D measurements, which fail to capture 3D vessel network complexity, and lack robust ground truths for assessment of segmentation accuracy. Here, we developed an in silico, phantom, in vivo, and ex vivo-validated end-to-end framework to quantify 3D vascular networks captured using mesoscopic PAI. We applied our framework to evaluate the capacity of rule-based and machine learning-based segmentation methods, with or without vesselness image filtering, to preserve blood volume and network structure by employing topological data analysis. We first assessed segmentation performance against ground truth data of in silico synthetic vasculatures and a photoacoustic string phantom. Our results indicate that learning-based segmentation best preserves vessel diameter and blood volume at depth, while rule-based segmentation with vesselness image filtering accurately preserved network structure in superficial vessels. Next, we applied our framework to breast cancer patient-derived xenografts (PDXs), with corresponding ex vivo immunohistochemistry. We demonstrated that the above segmentation methods can reliably delineate the vasculature of 2 breast PDX models from mesoscopic PA images. Our results underscore the importance of evaluating the choice of segmentation method when applying mesoscopic PAI as a tool to evaluate vascular networks in vivo.

Relation between venous pressure and blood volume in the intestine

1963 ◽  
Vol 204 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Paul C. Johnson ◽  
Kenneth M. Hanson
Keyword(s):  
Blood Volume ◽  
Time Constant ◽  
Time Course ◽  
Venous Pressure ◽  
High Viscosity ◽  
Exponential Process ◽  
Pressure Volume Relationship ◽  
Venous Volume ◽  
Volume Characteristics

The pressure volume characteristics of the intestinal venous vasculature were studied in vivo by a weight technique. The pressure-volume relationship was linear over the range 0–20 mm Hg. In a few experiments the volume increment appeared to be reduced at venous pressures above 30 mm Hg. The average compliance of the intestinal veins was 0.34 ml/mm Hg 100 g tissue. The time course of the blood volume change was also examined. Rapid elevation of venous pressure to a higher level caused blood volume to increase at an exponentially declining rate. Therefore, the phenomenon of creep in the intestinal veins appears to be a simple exponential process. The half time of the increase in venous volume averaged 7.5 sec while the time constant was 10.9 sec. The magnitude of the time constant suggests the presence of elements of rather high viscosity in the venous wall.

scholarly journals Dynamic Synchrotron Imaging of Diabetic Rat Coronary Microcirculation In Vivo

2012 ◽  
Vol 32 (2) ◽  
pp. 370-377 ◽  
Author(s):  
Mathew J. Jenkins ◽  
Amanda J. Edgley ◽  
Takashi Sonobe ◽  
Keiji Umetani ◽  
Daryl O. Schwenke ◽  
...  
Keyword(s):  
Coronary Microcirculation ◽  
Diabetic Rat ◽  
Synchrotron Imaging

Further Evidence in Vivo for a Circulating Natriuretic Substance after Expanding the Blood Volume in Rats

1980 ◽  
Vol 59 (6) ◽  
pp. 423-433 ◽  
Author(s):  
Catherine A. Knock
Keyword(s):  
Blood Volume ◽  
Sodium Excretion ◽  
Urinary Sodium Excretion ◽  
Significant Rise ◽  
Urinary Sodium ◽  
Bilateral Nephrectomy ◽  
Experimental Protocol ◽  
Equivalent Time

1. The blood volume of 18 rats was expanded with blood with which they were equilibrated. In another 18 rats undergoing the same experimental protocol, the blood volume was not expanded. 2. In some rats the urine was reinfused. 3. A 1 ml portion of plasma obtained either 1 h after the blood volume was expanded, or at an equivalent time from the control rats, was injected intravenously into an assay rat. 4. The injection of plasma produced a gradual and significant rise in sodium excretion in the assay rat when it was obtained from an animal with an expanded blood volume, the urine of which was being reinfused. 5. When the increase in blood volume was sustained by a preceding bilateral nephrectomy, instead of urine reinfusion, the injection of 1 ml of plasma into an assay rat did not cause a rise in urinary sodium excretion. 6. It is concluded that the natriuresis involved in the assay rat was caused by a natriuretic substance in the 1 ml of plasma obtained from the blood-volume-expanded urine-reinfused rat. 7. The experiments suggest that the natriuretic substance is excreted in the urine and may be produced in the kidney.

Sign in / Sign up

Export Citation Format

Share Document