Department of Radiology, Duke University Medical Center, Durham, NC, United States.
Department of Radiology, Duke University Medical Center, Durham, NC, United States.
Eur J Radiol. 2023 Sep;166:110998. doi: 10.1016/j.ejrad.2023.110998. Epub 2023 Jul 22.
To evaluate the utility of the PI-QUAL score in assessing protocol changes aimed to improve image quality from a non-endorectal coil prostate MR imaging protocol during a 9-month quality improvement (QI) project and to quantify the inter-reader agreement of PI-QUAL scores between radiologists, technologists, and physicists.
This retrospective study audited 1,012 multiparametric prostate MRI examinations as part of a national QI project according to the PI-QUAL standard. PI-QUAL scores were used to inform MR protocol changes. Following the project, 4 radiologists, 2 technologists, and 1 medical physicist collectively audited an additional set of 150 examinations to identify statistical improvements in image quality using the two-tailed Wilcoxon rank sum test. The improvements due to individual protocol changes were assessed among subsets of the 1,012 examinations which compared examinations occurring before and after the isolated protocol change. Inter-reader variability was assessed using the percent majority agreement and the average standard deviation of PI-QUAL scores between evaluators.
During this QI project, PI-QUAL scores improved from 3.67 ± 0.75 to 4.16 ± 0.59 (p < 0.01) after implementing a series of protocol changes. Among a subset of 451 cases, we found that adopting R/L rather than A/P phase encoding reduced distortion in diffusion-weighted imaging (DW) from 21.6% (41/190 A/P phase encoded cases) to 11.5% (30/261 R/L phase encoded cases) (p < 0.01). Similarly, in the same 451 cases, adopting R/L phase encoding in T2WI reduced breathing motion artifacts from 34.6% (94/272 A/P phase encoding cases) to 12.8% (23/179 R/L phase encoding cases) (p < 0.01). DWI wraparound artifact was mitigated by employing a full-pelvis shim and enabling the abdomen shim option. The occurrence of low signal-to-noise ratio was reduced from 19.4% (19/98 cases without a weight-based threshold) to 6.3% (10/160) by instituting a weight-based threshold for using an endorectal coil (p < 0.01). The percent majority agreement was similar between radiologists, technologists and physicists, and all evaluators combined (72%, 77%, and 67%, respectively).
PI-QUAL can evaluate image quality changes resulting from protocol optimizations at both the exam- and series-levels. With training, radiologists, technologists, and physicists can perform PI-QUAL scoring with similar performance. Broadening the scope of the quality improvement team can result in meaningful and lasting change.
评估 PI-QUAL 评分在评估旨在提高非直肠内线圈前列腺磁共振成像协议图像质量的方案变化方面的效用，以及量化放射科医生、技术员和物理学家之间 PI-QUAL 评分的读者间一致性。
本回顾性研究根据 PI-QUAL 标准对 1012 例多参数前列腺 MRI 检查进行了审核，作为国家质量改进 (QI) 项目的一部分。PI-QUAL 评分用于告知 MR 方案的变化。在项目完成后，4 名放射科医生、2 名技术员和 1 名医学物理学家共同审核了另外 150 例检查，使用双侧 Wilcoxon 秩和检验确定图像质量的统计学改善。通过比较孤立方案变化前后的 1012 次检查中的子集来评估各个方案变化的改善。使用评估者之间的多数一致百分比和 PI-QUAL 评分的平均标准偏差来评估读者间的变异性。
在这项 QI 项目中，在实施了一系列方案变化后，PI-QUAL 评分从 3.67 ± 0.75 提高到 4.16 ± 0.59(p<0.01)。在 451 例亚组中，我们发现采用 R/L 而不是 A/P 相位编码减少了扩散加权成像 (DW)中的失真，从 21.6%(41/190 A/P 相位编码病例)降至 11.5%(30/261 R/L 相位编码病例)(p<0.01)。同样，在相同的 451 例中，采用 R/L 相位编码在 T2WI 中减少了呼吸运动伪影，从 34.6%(94/272 A/P 相位编码病例)降至 12.8%(23/179 R/L 相位编码病例)(p<0.01)。通过使用全骨盆垫片和启用腹部垫片选项，可以减轻 DW 绕带伪影。通过为使用直肠内线圈建立基于体重的阈值，将低信噪比的发生率从 19.4%(98 例无基于体重的阈值病例)降低至 6.3%(160 例)，这降低了低信噪比的发生率(p<0.01)。
PI-QUAL 可以评估方案优化在检查和系列水平上导致的图像质量变化。经过培训，放射科医生、技术员和物理学家可以使用类似的性能进行 PI-QUAL 评分。扩大质量改进团队的范围可以带来有意义且持久的变化。
