Introduction Proton resonance frequency shift (PRFS) thermometry of the breast is often confounded not only by the presence of fat in the tissue but also by respiration-induced B0 changes even in the absence of detectable breast motion. We (and others) have measured B0 changes of up to 0.16ppm due to respiration[1] leading to temperature errors on the order of 16°C (due to the 0.01ppm/°C PRFS s...

PURPOSE Arthritis and bone trauma are often accompanied by bone marrow edema (BME). BME is challenging to detect in CT due to the overlaying trabecular structure but can be visualized using dual-energy (DE) techniques to discriminate water and fat. We investigate the feasibility of DE imaging of BME on a dedicated flat-panel detector (FPD) extremities cone-beam CT (CBCT) with a unique x-ray tub...

Fig.4: Temperature changes of a cheese phantom at the hottest voxel during FUS heating experiments. While measurements using GE fast gradient-echo sequence are echo time-dependent (a), the measurements using 2DRF pulse for fat suppression are very similar (b). With excitation pattern of Fig.2d, both fat suppression and 2D excitation were achieved, resulting in improvement in temporal resolution...

BACKGROUND AND PURPOSE Time-of-flight MR angiography (TOF MRA), with its advantage of high spatial resolution, is widely used for visualization of intracranial arteries. Fat signal intensity from bone marrow can interfere with vessel signal intensity, especially in maximum intensity projection reconstructions. Use of a technique such as fat saturation or water excitation can reduce this signal ...

PURPOSE Identifying water and fat unambiguously in multipoint Dixon imaging often requires phase correction, which can be challenging and may fail. The purpose of this work is to present a geometric interpretation of the two-point Dixon method with flexible echo times (TEs) and to investigate the conditions under which water and fat can be determined directly without phase correction. METHODS...

Figure 2: Phantom images and separated fat-only and water-only images for (a) FTED, (b) nulling at RF, (c) nulling at the echo center. Flow-artifacts are effectively reduced in (b) and (c). Note that water tube in (a) and (b) was incorrectly separated into the fat-only image because the existing region growing algorithm cannot handle disconnected objects. (c) (b) (a) Flow Compensation in Freque...

Figure 1. Demonstrations of the edge artifact observed in LGE (yellow arrow). .A-B are Bloch simulations of the Cartesian (A) and spiral LGE sequences for circles with T1 values of 300ms and 200ms (top circle and bottom circle respectively). C-D show phantom images acquired with the Cartesian LGE sequence, where the edge artifact can be observed with greater intensity for increasing acquisition...

Tissue harmonic imaging (THI) has been reported to improve contrast resolution, tissue differentiation and overall image quality in clinical examinations. However, a study carried out previously by the authors (Brown et al. 2004) found improvements only in spatial resolution and not in contrast resolution or anechoic target detection. This result may have been due to the homogeneity of the phan...

Purpose : The objective of this study was to develop background gradient correction method using excitation pulse profile compensation for accurate fat and T2* quantification in the liver. Materials and Methods: In liver imaging using gradient echo, signal decay induced by linear background gradient is weighted by an excitation pulse profile and therefore hinders accurate quantification of T2* ...