Conventional Fast Spin-echo Images Research Articles

High-Resolution Single-Shot Fast Spin-Echo MR Imaging with Deep Learning Reconstruction Algorithm Can Improve Repeatability and Reproducibility of Follicle Counting.

To investigate the diagnostic performance of high-resolution single-shot fast spin-echo (SSFSE) imaging with deep learning (DL) reconstruction algorithm on follicle counting and compare it with original SSFSE images and conventional fast spin-echo (FSE) images. This study included 20 participants (40 ovaries) with clinically confirmed polycystic ovary syndrome (PCOS) who underwent high-resolution ovary MRI, including three-plane T2-weighted FSE sequences and slice-matched T2-weighted SSFSE sequences. A DL reconstruction algorithm was applied to the SSFSE sequences to generate SSFSE-DL images, and the original SSFSE images were also saved. Subjective evaluations such as the blurring artifacts, subjective noise, and clarity of the follicles on the SSFSE-DL, SSFSE, and conventional FSE images were independently conducted by two observers. Intra-class correlation coefficients and Bland-Altman plots were used to present the repeatability and reproducibility of the follicle number per ovary (FNPO) based on the three types of images. SSFSE-DL images showed less blurring artifact, subjective noise, and better clarity of the follicles than SSFSE and FSE (p < 0.05). For the repeatability of the FNPO, SSFSE-DL showed the highest intra-observer (ICC = 0.930; 95% CI: 0.878-0.962) and inter-observer (ICC = 0.914; 95% CI: 0.843-0.953) agreements. The inter-observer 95% limits of agreement (LOA) for SSFSE-DL, SSFSE, and FSE ranged from -3.7 to 4.5, -4.4 to 7.0, and -7.1 to 7.6, respectively. The intra-observer 95% LOA for SSFSE-DL, SSFSE, and FSE ranged from -3.5 to 4.0, -5.1 to 6.1, and -5.7 to 4.2, respectively. The absolute values of intra-observer and inter-observer differences for SSFSE-DL were significantly lower than those for SSFSE and FSE (p < 0.05). Compared with the original SSFSE images and the conventional FSE images, high-resolution SSFSE images with DL reconstruction algorithm can better display follicles, thus improving FNPO assessment.

SU‐FF‐I‐33: T2‐Weighted Prostate Imaging Using Echo‐Planar Imaging at 3T

Purpose: T2‐weighting in fast spin echo (FSE) images is unavoidably affected by T1‐mixing due to stimulated echoes. The purpose of this research is to evaluate the feasibility of using a multishot echo‐planar (EPI) technique to image the prostate at 3 Tesla without an endorectal coil and to compare T2 quantification using EPI with that based off of FSE images. Method and Materials: All experiments were performed on a GE Signa 3 Tesla whole body scanner with an 8‐channel torso phased‐array coil. T2‐weighted images were acquired of a healthy volunteer at echo times (TEs) of 40, 80 and 110 ms with a multishot spin‐echo EPI. Other imaging parameters were: 32cm FOV, 16 shots, TR = 2000ms, acquisition matrix = 256×512, receiver bandwidth = ±250 kHz. FSE images were obtained of the same volunteer with TEs of 60, 120, and 180ms and these acquisition parameters: 16cm FOV, TR = 3900ms, acquisition matrix = 256×256, ETL = 16, bandwidth = ±32kHz. A total of eleven slices covering the entire prostate were collected using both techniques. Results: The EPI images showed few artifacts and were noted to provide better T2‐contrast than the FSE images. For a region‐of‐interest in the peripheral zone of the prostate, T2 values derived from FSE images (134±15 ms) are substantially larger than those based on EPI images (76±1 ms). This observation is consistent with the apparent lengthening of T2 due to T1 mixing in FSE images. Conclusion: Using EPI with high receiver bandwidth, our results indicate that high quality T2‐weighted images of the prostate can be obtained at 3T without an endorectal coil. T2‐weighted images by EPI provide pure T2‐contrast and possibly more accurate T2‐determination than conventional FSE images.

Herniated Intervertebral Disc

AbstractOne of the most significant impacts of magnetic resonance imaging (MRI) has been its ability to exquisitely depict normal and pathologic anatomy of the spine. This unit presents a basic protocol for conventional fast spin echo imaging of the spine. An alternate protocol is presented for gradient recalled echo acquisitions that may be used in the sagittal and/or transverse planes to clearly distinguish between discs and soft tissue and to clarify the spinal neural foramen in the cervical region. A second alternate protocol is presented for contrast enhanced MRI acquisitions.