Optimal post‐contrast timing of breast MR image acquisition for architectural feature analysis

Abstract

Purpose: To define a post-contrast imaging time span during which diagnostic accuracy of breast magnetic resonance (MR) architectural feature analysis is maintained. Materials and Methods:Seventy-five patients with mammographically-visible or palpable findings underwent MR examination. Three sequential post-contrast, fat-saturated, three-dimensional gradient-echo imaging runs were acquired spanning 0 -90, 90 -180, and 180 -270 seconds after contrast injection. Five readers independently predicted the malignant potential of the MR abnormalities.Results: Receiver-operator characteristics (ROC) curves were our primary measure of diagnostic accuracy. The accuracy of four readers was unchanged over the three postcontrast runs. One reader was slightly more accurate using the second and third runs than using the first. Conclusion:For most readers, a single post-contrast run performed at any point during the first four minutes and 30 seconds following injection should yield an equivalent diagnostic accuracy. If any time period is less optimal, it is that of our first run, performed between 0 -90 seconds after contrast injection.

Dual-energy contrast-enhanced digital breast tomosynthesis – a feasibility study

“…This feature of their biology can differentiate them on imaging from benign breast tissue via the uptake of the intravenous contrast agent. Currently, CE-MRI and gadolinium are used to obtain breast lesion morphology and vascular enhancement information [3,5,6,29]. Recently, CE-DBT has been reported to be a potential alternative method for imaging malignant breast lesion morphology and vascular enhancement patterns [8].…”

“…As a result, the absorption of vascular contrast agents in malignant breast tissue is often different to that in benign and normal tissues. Today, contrast-enhanced MRI (CE-MRI), which uses a gadolinium chelate as a vascular contrast agent, is the standard for vascular imaging of breast cancers [2][3][4][5][6][7]. Breast lesion characterisation with CE-MRI relies on a combination of the analysis of the morphological features of the lesion and the vascular enhancement kinetics.…”

Contrast-enhanced MRI in breast cancer patients eligible for breast-conserving therapy: complementary value for subgroups of patients

“…One series was acquired before and four series after intravenous injection of contrast agent (ProHance, Bracco-Byk Gulden, Konstanz, Germany; 0.1 mmol/kg body weight, at a rate of 2-4 ml/s). The series were acquired at intervals of approximately 120 s to achieve theoretically optimal time points to describe contrast uptake in the lesion [34][35][36][37] and to achieve isotropic voxel sizes. The following MRI parameters were used: T1-weighted sequence, repetition time 8.1 ms, echo time 4.0 ms, reconstructed in-plane matrix 256×256 pixels, isotropic in-plane resolution of 1.35×1.35 mm 2 , slice thickness 1.35 mm, no fat suppression.…”

X-Ray Polarization Imaging

“…As a result, the signal from tumors appears enhanced. This enhancement permits depiction of architectural features, such as irregularity of the lesion boundary or spiculations; the importance of this was recently emphasized in a study of how the timing of image acquisition relative to injection affects the discernment of such features (11). Much attention has been paid in the MR imaging literature to the time dependence of the enhancement of the lesion and the later "washout," which Leach (12) has reviewed concisely.…”

“…Two ion chambers where mounted at right angles to the beam, and at right angles to each other (θ=π/2, φ= 0 and π/2 ), 60 cm from the analyzer. The primary photon fluence incident upon the analyzer was estimated to be 2×10 11 , while the scattered fluence at the detector in the direction perpendicular to polarization was 2×10 6 cm -2 . We have thus observed x-ray polarization, measuring P pol =0.10.…”