Small Field-of-view single-shot EPI-DWI of the prostate: Evaluation of spatially-tailored two-dimensional radiofrequency excitation pulses

Comparison of reduced field‐of‐view diffusion‐weighted imaging (DWI) and conventional DWI techniques in the assessment of rectal carcinoma at 3.0T: Image quality and histological T staging

“…However, the rFOV DWI sequence exhibited no RF crosstalk among slices and accelerates the traversal through the k ‐space line along the phase‐encoding direction with a shortened readout, thus improving the IQ with fewer distortions and artifacts . These superiorities of the rFOV DWI sequence compared with the fFOV DWI sequence, in terms of higher resolution with excellent fat suppression and diminished susceptibility artifacts, more clearly reveal the details of rectal cancer . In addition, the rFOV DWI sequence provides more specific features, including necrotic, cystic, and bleeding areas of tumors, and improves the confidence of qualitative and quantitative diagnosis …”

Diffusion parameter mapping with the combined intravoxel incoherent motion and kurtosis model using artificial neural networks at 3 T

“…In the simplest case, a monoexponential fit can be applied yielding the apparent diffusion coefficient (ADC) . For low b ‐values, flow effects in perfused biological tissue also contribute to signal attenuation.…”

Update on multiparametric MRI of urinary bladder cancer

“…The sensitivity of EPI to off‐resonance is dependent on the rate at which k ‐space is sampled along the phase‐encoding direction; therefore, reducing the imaging FOV along the phase‐encoding direction should reduce sensitivity of EPI to susceptibility artifacts. Studies evaluating reduced FOV EPI in the pelvis (FOCUS, GE Healthcare, and Z‐EPI, Siemens Healthcare) have shown improved image quality and reduced artifact compared with conventional single‐shot EPI of the whole pelvis . In a case series by Rosenkrantz and Taneja, reduced FOV EPI provided diagnostic quality images in patients undergoing prostate MRI with hip prosthesis, which is otherwise generally not possible due to severe artifact encountered with conventional single‐shot EPI .…”

“…In segmented readout EPI, the same diffusion preparation is used as in single‐shot EPI; however, the k ‐space trajectory is divided into multiple segments in the readout direction with 2D Navigator echoes to reduce sensitivity to motion (RESOLVE, Siemens Healthcare) . This sampling scheme has been shown to reduce artifact and improve image quality compared to conventional k ‐space sampling in single‐shot EPI in the pelvis . Another advantage of reduced FOV DWI is higher spatial resolution compared to whole‐pelvis single‐shot EPI; however, smaller FOV and higher matrix sizes result in lower SNR compared to whole pelvis EPI, which requires a period of adjustment for the user and radiologists should be aware that the use of reduced FOV DWI for imaging of an organ (in this case, the bladder) results in an inability to assess the remainder of the pelvis, for example, to detect lymph node metastases.…”