Anne M. Sawyer-Glover

Relaxation times of breast tissue at 1.5T and 3T measured using IDEAL.

To accurately measure T1 and T2 of breast fibroglandular tissue and fat at 1.5T and 3T, and note the partial volume effects of the admixture of fibroglandular tissue and fat on the relaxation rates using an approach termed iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL) imaging.

Pre‐MRI Procedure Screening: Recommendations and Safety Considerations for Biomedical Implants and Devices

Maintaining a safe MR environment is a daily challenge for MR healthcare workers, especially in consideration of the increasing number of clinical MR applications and the large and growing variety of biomedical implants and devices that are currently used in patients. This review article presents policies and procedures that should be used to screen all patients and individuals before allowing them to enter the magnetic resonance (MR) environment. Information pertaining to MR safety and the relative risk factors for implants, devices and materials is discussed. A comprehensive pre‐MRI procedure screening form that is recommended for use by MR facilities is also included. J. Magn. Reson. Imaging 2000;12:92–106.

Experience-dependent asymmetric variation in primate prefrontal morphology.

Theories of human development suggest that experiences embedded in social relationships alter prefrontal brain systems that mediate emotional self-regulation. This study tests for experience-dependent effects on prefrontal gray and white matter volumes determined in 39 young adult monkeys (Saimiri sciureus) 4 years after conditions that modified early maternal availability. These conditions were previously shown to alter subsequent measures of emotional behavior, social propensities, and hypothalamic-pituitary-adrenal axis stress physiology. Here we identify significant differences in right but not left adult prefrontal volumes, with experience-dependent asymmetric variation most clearly expressed in ventral medial cortex measured in vivo by magnetic resonance imaging (MRI). Follow-up studies now need to determine whether maternal availability directly affects or interacts with subsequent experiences to alter prefrontal substrates of emotional processing and sensitivity to stress.

Characterization of breast lesion morphology with delayed 3DSSMT: an adjunct to dynamic breast MRI.

The purpose of the study was to determine the sensitivity and specificity of various morphologic criteria in distinguishing malignant from benign breast lesions using a new sequence (3DSSMT) performed immediately after dynamic breast MRI. 3DSSMT combines a water‐selective spectral‐spatial excitation and an on‐resonance magnetization transfer pulse with three‐dimensional spoiled gradient‐echo imaging. Morphologic features of 87 pathologically confirmed lesions were analyzed. The presence of either skin thickening, or a combination of a spiculated or microlobulated border, with a rim, ductal, linear, or clumped enhancement pattern was 94% specific and 54% sensitive for malignancy. Conversely, the presence of either a perfectly smooth border, a well‐defined margin, non‐enhancing internal septations, or a macrolobulated border was 97% specific and 35% sensitive for a benign diagnosis. In conclusion, delayed 3DSSMT discriminates a significant number of benign and malignant breast lesions; it has the potential to improve the diagnostic accuracy of dynamic breast MRI. J. Magn. Reson. Imaging 2000;11:87–96.

Dynamic breast MRI with spiral trajectories: 3D versus 2D

A three‐dimensional (3)D spiral sequence was developed for dynamic breast magnetic resonance (MR) imaging with much improved image quality. Partial Z phase encoding was applied to obtain thinner slices for a coverage of the whole breast. Comparison between the 3D and a previously developed multi‐slice 2D spiral sequences was performed on ten healthy volunteers without contrast and five breast patients with gadolinium‐diethylene triamine pentaacetic acid (Gd‐DTPA). The 3D spiral images had significantly less off‐resonance blurring and spiral artifacts. With a small compromise on temporal resolution (7.7 seconds in 2D and 10.6 seconds in 3D), we obtained 32 interpolated 3–5 mm slices (with 20 Z phase encodes) for a full coverage of 10–16 cm breast with the same 1 × 1 mm 2 in‐plane resolution as the 2D sequence, which haad 12 8–13 mm slices. Contrast between glandular and soft tissue in normal breasts was increased by about 25%. The reduced repetition time in the 3D spiral acquisition led to an increased Gd‐enhanced signal. The difference between the enhancement of malignant and benign lesions increased by sevenfold. We expect that this new development could lead to improved specificity in characterizing breast lesions using MR imaging. J. Magn. Reson. Imaging 2000;11:351–359.