Super Resolution for Improved Multislice Prostate MRI

项目摘要/摘要 前列腺癌(PCa)是世界上最常见和第二致命的男性非皮肤癌。 美国，但如果及早发现，五年存活率接近100%是可能的。前列腺核磁共振已经成为 在癌症检测和定位方面日益重要。二维(2D)多层螺旋CT T2加权 自旋回波(T2SE)和弥散加权(DWI)扫描是临床前列腺癌MRI的主要扫描方式，但RADI-T2SE和DWI增强扫描对前列腺癌的诊断价值不大。 由于通面分辨率比面内分辨率粗3-8倍，阻碍了地质解释。 这在前列腺移行区(TZ)尤其有限，在那里松弛时间的差异 恶性组织和正常组织之间的区别很小，解释通常是基于与锐度相关的标准 例如封装。根据PI-RADSv2.1，T2SE是关键序列。报告的敏感度远远低于 理想的，30%到70%。除了在TZ中提高诊断准确性的具体需要外，还有 倡议使前列腺核磁共振检查更短、更有效。因此，有必要调和这些 通过减少局部体积效应和提高效率来提高分辨率和对比度的相互竞争的需求 前列腺核磁共振检查的准确性。我们开发了一种T2SE的超分辨率(SR)方法，该方法使用重叠的、 标准厚度(3 Mm)轴向切片，形成1 mm切片，在KZ空间中重建，称为KZ-多切片 (KZM)。我们已经在体内展示了合成图像相对于同等情况下的3 mm切片的更高的清晰度 面内分辨率。最近，我们开发了一种方法，实际上消除了- 一致性破坏了当前的KZM重建并降低了图像质量。我们的中心假设是 在可行性研究中显示的这种KZM方法现在可以在技术上显著改进到模拟- 提供更高的穿透平面分辨率并允许缩短扫描时间，从而实现高效的技术- NIKI可提高临床前列腺癌T2SE和DWI MRI的性能。我们建议： 1.开发适用于SR前列腺T2SE的快速、高质量、多层面采集技术。我们会 结合非传统的射频激励脉冲，以提高KZ的保真度。我们将同时使用多个 切片(Sms)可减少扫描时间，统计重建可保持SNR。我们将开发方法来 在扫描过程中测量1-2 mm的微小A/P前列腺运动，从而实现准确的运动校正。 2.将T2SE的SR方法推广到前列腺的弥散加权成像。分段收购将提供 以实现切片到切片的位置一致性。SR重建将根据所使用的单个b值进行调整。站台- 组织重建将保留SNR，允许ADC的薄层图像。 3.将随机共振技术应用于多层前列腺MRI。我们将评估我们在临床上的技术发展 评估，比较传统的T2SE和我们的超级缩写考试(SAE)的新SR方法。 我们还将评估我们的T2SE KZM方法在提高检测过渡区PCA的准确性方面的作用。

PROJECT SUMMARY / ABSTRACT Prostate cancer (PCa) is the most common and second most deadly non-cutaneous cancer in men in the USA, but five-year survival rates approaching 100% are possible if detected early. Prostate MRI has become increasingly important in cancer detection and localization. Two-dimensional (2D) multislice T2-weighted spin-echo (T2SE) and diffusion-weighted (DWI) acquisitions are mainstays of clinical prostate MRI, but radi- ological interpretation is hindered because through-plane resolution is 3–8× coarser than inplane resolution. This is particularly limiting in the transition zone (TZ) of the prostate where differences in relaxation times between malignant and normal tissue are small, and interpretation is often based on sharpness-related criteria such as encapsulation. Per PI-RADSv2.1, T2SE is the critical sequence. Reported sensitivity is far less than ideal, 30 to 70%. In addition to the specific need for improved diagnostic accuracy in the TZ, there is an initiative to make prostate MRI exams shorter and more efficient. Thus, there is a need to reconcile these competing demands of improved resolution and contrast via reduced partial volume effects with higher effi- ciency in prostate MRI. We have developed a super resolution (SR) method for T2SE which uses overlapped, standard-thickness (3mm) axial slices to form 1mm slices with reconstruction in kZ-space, dubbed kZ-multislice (KZM). We have shown in vivo the superior sharpness of the resultant images vs. 3mm slices for equal inplane resolution. More recently we have developed methods which virtually eliminate the slice-to-slice in- consistency disrupting current KZM reconstruction and degrading image quality. Our central hypothesis is that this KZM approach shown in feasibility studies can now be markedly improved technically to simultane- ously provide improved through-plane resolution and allow reduced scan time, resulting in an efficient tech- nique enabling improved performance of clinical prostate T2SE and DWI MRI. We propose to: 1. Develop techniques for rapid, high quality, multislice acquisition suitable for SR prostate T2SE. We will incorporate non-traditional RF excitation pulses for improved fidelity in kZ. We will use simultaneous multi- slice (SMS) to reduce scan time and statistical reconstruction to retain SNR. We will develop means to measure the small, 1-2 mm A/P prostate motion during the scan, allowing accurate motion correction. 2. Extend the SR methodology developed for T2SE to DWI of the prostate. Segmented acquisition will provide for slice-to-slice positional consistency. SR reconstruction will be tuned to the individual b-values used. Sta- tistical reconstruction will retain SNR, allowing thin-slice images of the ADC. 3. Apply SR techniques to multislice prostate MRI. We will evaluate our technical developments in clinical evaluations, comparing conventional T2SE with our new SR method for a Super Abbreviated Exam (SAE). We will also evaluate our T2SE KZM method on improved accuracy in detecting PCa in the transition zone.