Variability and bias assessment in breast ADC measurement across multiple systems.

Purpose: To assess the ability of a recent, anatomically designed breast phantom incorporating T1 and diffusion elements to serve as a quality control device for quantitative comparison of apparent diffusion coefficient (ADC) measurements calculated from diffusion-weighted MRI (DWI) within and across MRI systems.

Materials And Methods: A bilateral breast phantom incorporating multiple T1 and diffusion tissue mimics and a geometric distortion array was imaged with DWI on 1.5 Tesla (T) and 3.

Design of a breast phantom for quantitative MRI.

Purpose: We present a breast phantom designed to enable quantitative assessment of measurements of T1 relaxation time, apparent diffusion coefficient (ADC), and other attributes of breast tissue, with long-term support from a national metrology institute.

Materials And Methods: A breast phantom was created with two independent, interchangeable units for diffusion and T1 /T2 relaxation, each with flexible outer shells. The T1 unit was filled with corn syrup solution and grapeseed oil to mimic the relaxation behavior of fibroglandular and fatty tissues, respectively.

Repeatability of quantitative MRI measurements in normal breast tissue.

Purpose: To evaluate the variability and repeatability of repeated magnetic resonance imaging (MRI) measurements in normal breast tissues between and within subjects.

Methods: Eighteen normal premenopausal subjects underwent two contrast-enhanced MRI scans within 72 hours or during the same menstrual phase in two consecutive months. A subset of nine women also completed diffusion-weighted imaging (DWI).

Real-Time Measurement of Functional Tumor Volume by MRI to Assess Treatment Response in Breast Cancer Neoadjuvant Clinical Trials: Validation of the Aegis SER Software Platform.

Purpose: To evaluate the Aegis software implementation for real-time calculation of functional tumor volume (FTV) in the neoadjuvant breast cancer treatment trial setting.

Methods: The validation data set consisted of 689 contrast-enhanced magnetic resonance imaging (MRI) examinations from the multicenter American College of Radiology Imaging Network 6657 study. Subjects had stage III tumors ≥3 cm in diameter and underwent MRI before, during, and after receiving anthracycline-cyclophosphamide chemotherapy.

Motor-induced suppression of the auditory cortex.

Sensory responses to stimuli that are triggered by a self-initiated motor act are suppressed when compared with the response to the same stimuli triggered externally, a phenomenon referred to as motor-induced suppression (MIS) of sensory cortical feedback. Studies in the somatosensory system suggest that such suppression might be sensitive to delays between the motor act and the stimulus onset, and a recent study in the auditory system suggests that such MIS develops rapidly. In three MEG experiments, we characterize the properties of MIS by examining the M100 response from the auditory cortex to a simple tone triggered by a button press.