Purpose: To assess the distribution of respiration and cardiac motion-induced field fluctuations in the breast and to evaluate the implications of such fluctuations for proton resonance frequency shift (PRFS) MR thermometry in the breast.
Materials And Methods: Gradient echo MR field maps were made to study the effect of regular respiration, maximum capacity respiration, and cardiac motion on the stability of the local magnetic field in four healthy female volunteers. Field fluctuations (in parts-per-million [ppm]) were averaged over a region of interest covering both breasts.
Results: The average field fluctuation due to regular respiration was 0.13 ppm, due to maximum capacity respiration 0.16 ppm and <0.03 ppm due to cardiac motion. These fluctuations can be misinterpreted as temperature changes of 13, 16, and 3 degrees C when PRFS-based MR thermometry is used during thermal treatment of breast cancer.
Conclusion: Respiration causes significant field fluctuations in the breast. If MR thermometry were to be safely used in clinical practice, these fluctuations should be taken into account and should probably be corrected for.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/jmri.21680 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Physiological monitoring to prevent diving disorders.
Front Physiol
December 2024
The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States.
Insight into human physiology is key to maintaining diver safety in underwater operational environments. Numerous hazardous physiological phenomena can occur during the descent, the time at depth, the ascent, and the hours after a dive that can have enduring consequences. While safety measures and strict adherence to dive protocols make these events uncommon, diving disorders still occur, often with insufficient understanding of the factors that triggered the event.
View Article and Find Full Text PDFEffects of Graphene Quantum Dots on Renal Fibrosis Through Alleviating Oxidative Stress and Restoring Mitochondrial Membrane Potential.
Adv Sci (Weinh)
December 2024
Department of Kidney Research Institute, Seoul National University Medical Research Center, Seoul, South Korea.
Podocyte injury and proteinuria in glomerular disease are critical indicators of acute kidney injury progression to chronic kidney disease. Renal mitochondrial dysfunction, mediated by intracellular calcium levels and oxidative stress, is a major contributor to podocyte complications. Despite various strategies targeting mitochondria to improve kidney function, effective treatments remain lacking.
View Article and Find Full Text PDFOn the causal connection in lifespan correlations and the possible existence of a 'number of life' at molecular level.
Sci Rep
December 2024
Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile.
Multiple physiological traits correlates with lifespan, being unclear both the causal connection among them and with the process of ageing. In this paper, we show that six traits (such as metabolic rate, mass, heart rate, etc) acting at the system level, are all related to lifespan thru the existence of an approximately constant number of respiration cycles in a lifespan ([Formula: see text]), therefore, we find that those relationships are not independently related to ageing. In addition, we study if the approximately constant [Formula: see text] is possibly linked with the end-of-lifespan somatic mutation burden, another number recently found to be approximately constant (Cagan, Nature 604:517-524, 2022).
View Article and Find Full Text PDFReal-Time 2D Phase-Contrast MRI to Assess Cardiac- and Respiratory-Driven CSF Movement in Normal Pressure Hydrocephalus.
J Neuroimaging
December 2024
Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
Background And Purpose: In idiopathic normal pressure hydrocephalus (iNPH) patients, cerebrospinal fluid (CSF) flow is typically evaluated with a cardiac-gated two-dimensional (2D) phase-contrast (PC) MRI through the cerebral aqueduct. This approach is limited by the evaluation of a single location and does not account for respiration effects on flow. In this study, we quantified the cardiac and respiratory contributions to CSF movement at multiple intracranial locations using a real-time 2D PC-MRI and evaluated the diagnostic value of CSF dynamics biomarkers in classifying iNPH patients.
View Article and Find Full Text PDFHypoxia-induced TPC2 transcription and glycosylation aggravates pulmonary arterial hypertension by blocking autophagy flux.
Sci Rep
December 2024
Department of Respiratory Medicine, Hunan Provincial People's Hospital (The First-Affiliated Hospital of Hunan Normal University), No. 61 Jiefang Xi Road, Changsha, Hunan, 410219, China.
Pulmonary arterial hypertension (PAH) is a serious medical condition that causes a failure in the right heart. Two-pore channel 2 (TPC2) is upregulated in PAH, but its roles in PAH remain largely unknown. Our investigation aims at the mechanisms by which TPC2 regulates PAH development.
View Article and Find Full Text PDFWant 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!