MRI of brain tissue oxygen tension under hyperbaric conditions.

Neuroimage

Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, United States; Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, United States; South Texas Veterans Health Care System, Department of Veterans Affairs, San Antonio, TX, United States. Electronic address:

Published: June 2016

The brain depends on a continuous supply of oxygen to maintain its structural and functional integrity. This study measured T1 from MRI under normobaric air, normobaric oxygen, hyperbaric air, and hyperbaric oxygen (HBO) conditions as a marker of tissue pO2 since dissolved molecular oxygen acts as an endogenous contrast agent. Brain tissue T1 decreased corresponding to increased pO2 with increasing inhaled oxygen concentrations, and tissue oxygenation was estimated from the T1 changes between different inhaled oxygen levels. Tissue pO2 difference maps between different oxygen conditions showed heterogeneous pO2 changes in the brain. MRI-derived tissue pO2 was markedly lower than the arterial pO2 but was slightly higher than venous pO2. Additionally, for comparison with published extracellular tissue pO2 data obtained using oxygen electrodes and other invasive techniques, a model was used to estimate extracellular and intracellular pO2 from the MRI-derived mean tissue pO2. This required multiple assumptions, and so the effects of the assumptions and parameters used in modeling brain pO2 were evaluated. MRI-derived pO2 values were strongly dependent on assumptions about the extra- and intracellular compartments but were relatively less sensitive to variations in the relaxivity constant of oxygen and contribution from oxygen in the cerebral blood compartment. This approach may prove useful in evaluating tissue oxygenation in disease states such as stroke.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5313390PMC
http://dx.doi.org/10.1016/j.neuroimage.2016.03.040DOI Listing

Publication Analysis

Top Keywords

tissue po2
20
po2
12
oxygen
11
tissue
9
brain tissue
8
inhaled oxygen
8
tissue oxygenation
8
mri-derived tissue
8
mri brain
4
tissue oxygen
4

Similar Publications

Hypoxia, a condition of oxygen tension lower than physiological level, plays a crucial role in shaping the tumor microenvironment and modulates distinct cell populations activity. The tumor suppressor PTEN regulates angiogenesis, a process involving endothelial cells (ECs). Pathological in tumors, it is crucial for growth.

View Article and Find Full Text PDF

Using Fourier Transform Infrared spectroscopy (FTIR), it is possible to show chemical composition of materials and / or profile chemical changes occurring in tissues, cells, and body fluids during onset and progression of diseases. For diagnostic application, the use of blood would be the most appropriate in biospectroscopy studies since, (i) it is easily accessible and, (ii) enables frequent analyses of biochemical changes occurring in pathological states. At present, different studies have investigated potential of serum, plasma and sputum being alternative biofluids for lung cancer detection using FTIR.

View Article and Find Full Text PDF

Background Venous blood gas (VBG) investigation is a widespread option for arterial blood gas analysis because it is easier to draw and has a lower risk of complications during phlebotomy. This study aimed to establish reference intervals for the accurate analysis of VBG results as there is a lack of published data. Method Dr.

View Article and Find Full Text PDF

Hibernating mammals experience severe hemodynamic changes over the torpor-arousal cycle, with oxygen consumption reaching peaks during the early stage of torpor to re-enter arousal. Melatonin (MT) can improve mitochondrial function and reduce oxidative stress and inflammation. However, the regulatory mechanisms of MT action on the vascular protective function of hibernators are still unclear.

View Article and Find Full Text PDF

Metastatic sarcomatoid renal cell carcinoma (sRCC) is a significant therapeutic and diagnostic challenge due to its rarity and aggressiveness, which contribute to its poor prognosis. This case report presents the case of a 47-year-old Caucasian man with shortness of breath and right-sided abdominal pain. History revealed an extensive smoking history, a left renal mass diagnosed two months ago with inconclusive results, and an enlarged mass on computed tomography (CT) scan one week ago in an emergency department (ED) visit that showed signs consistent with metastatic disease.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!