Detecting gas‐induced vasomotor changes via blood oxygenation level‐dependent contrast in healthy breast parenchyma and breast carcinoma

Abstract

PurposeTo evaluate blood oxygenation level‐dependent (BOLD) contrast changes in healthy breast parenchyma and breast carcinoma during administration of vasoactive gas stimuli.Materials and MethodsMagnetic resonance imaging (MRI) was performed at 3T in 19 healthy premenopausal female volunteers using a single‐shot fast spin echo sequence to acquire dynamic T 2‐weighted images. 2% (n = 9) and 5% (n = 10) carbogen gas mixtures were interleaved with either medical air or oxygen in 2‐minute blocks, for four complete cycles. A 12‐minute medical air breathing period was used to determine background physiological modulation. Pixel‐wise correlation analysis was applied to evaluate response to the stimuli in breast parenchyma and these results were compared to the all‐air control. The relative BOLD effect size was compared between two groups of volunteers scanned in different phases of the menstrual cycle. The optimal stimulus design was evaluated in five breast cancer patients.ResultsOf the four stimulus combinations tested, oxygen vs. 5% carbogen produced a response that was significantly stronger (P < 0.05) than air‐only breathing in volunteers. Subjects imaged during the follicular phase of their cycle when estrogen levels typically peak exhibited a significantly smaller BOLD response (P = 0.01). Results in malignant tissue were variable, with three out of five lesions exhibiting a diminished response to the gas stimulus.ConclusionOxygen vs. 5% carbogen is the most robust stimulus for inducing BOLD contrast, consistent with the opposing vasomotor effects of these two gases. Measurements may be confounded by background physiological fluctuations and menstrual cycle changes. J. Magn. Reson. Imaging 2016;44:335–345.

Diffusion‐weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping as a quantitative imaging biomarker for prediction of immunohistochemical receptor status, proliferation rate, and molecular subtypes of breast cancer

“…D YNAMIC CONTRAST-ENHANCED magnetic resonance imaging (DCE-MRI) is the backbone of any given MRI protocol, but to address limitations in specificity and to improve breast cancer diagnosis, a plethora of functional MRI parameters, ie, diffusion-weighted imaging (DWI), proton and phosphorus MR spectroscopy, sodium imaging, blood oxygenation level-dependent imaging, and chemical exchange saturation transfer imaging are being investigated. [1][2][3][4][5][6][7] In this context, DWI with apparent diffusion coefficient (ADC) mapping is one of the most useful MRI parameter and is now often used in a multiparameric imaging setting for breast cancer detection. 2,5,8,9 DWI with ADC mapping provides information on tissue microstructure and cellularity that can be used for lesion characterization.…”

Insights into Hypoxia: Non-invasive Assessment through Imaging Modalities and Its Application in Breast Cancer

“…This is synthesized in a hypoxic environment to counteract the effects of the tissue oxygen deprivation changing the threshold, at which hypoxia might be considered pathological. Also, breast tissue has a complex architecture and a variable oxygen demand due to background physiological fluctuations secondary to menstrual cycle changes [8].…”

Impact of physiological noise correction on detecting blood oxygenation level-dependent contrast in the breast

“…These studies suggest that BOLD MRI may aid patient stratification for hypoxia-targeted therapies and has potential to provide early predictive response monitoring. Other studies in the breast have shown that 100% oxygen interleaved with carbogen (5% CO 2 , 95% O 2 ) in a block design is the optimal stimulus for inducing BOLD contrast (Rakow-Penner et al 2010 , Wallace et al 2016a ). Carbon dioxide is a potent vasodilator and the opposing effects of these two gases on vascular tone provide a mechanism for BOLD contrast, which is also sensitive to changes in blood volume and flow.…”