Department of Nuclear Medicine, Medical University of Łódź, ul. Czechosłowacka 8/10, 92-216 Łódź, Poland.
Department of Quality Control and Radiological Protection, Medical University of Łódź, ul. Czechosłowacka 8/10, 92-216 Łódź, Poland.
Nucl Med Rev Cent East Eur. 2020;23(2):84-88. doi: 10.5603/NMR.2020.0018.
One of the main indications for DRS is a diagnosis of obstructive uro-/nephropathy. In standard practice, this study includes the assessment of sequential scintigraphic images, renographic curves and such quantitative parameters as TMAX, T1/2 and split function of each kidney (SF). Due to the relative nature of SF and limitations of diagnostic capabilities of TMAX and T1/2, DRS was expanded to include new quantitative parameters describing kidney function in absolute values. This study aims to evaluate the usefulness of kidney efficiency index (KEi) - new, in-house developed parameter proportional to the average clearance function of the kidney.
The study included 156 people aged 18-84 (average 51) years. The first group, from which normative values of new parameters were determined, consisted of 20 healthy volunteers. The second group consisted of 136 patients selected retrospectively, based on archived scintigraphic data. "Normalcy rate" (percentage of normal results among selected 62 patients with a low likelihood of obstructive uro-/nephropathy) was used to evaluate the reliability of KEi. A comparative differential analysis of obstructive uro-/nephropathy, based on standard and new DRS parameters, was performed on selected 74 patients (92 kidneys) with single functioning kidney or bilateral obstructive uropathy, where SF is unreliable.
Normative values: KEi ≥ 8; Normalcy rate for KEi: 95%. In comparison with standard DRS evaluation, application of KEi changed the diagnosis in 1/3 of assessed kidneys (from uropathy to nephropathy in 27/92 kidneys and vice versa in 4 kidneys).
KEi enables reproducible, quantitative assessment of absolute kidney function without any modifications of the standard DRS protocol. Its values can be compared between independent studies (e.g. follow-up examinations). KEi corrected the diagnosis of obstructive uro-/nephropathy in cases of single functioning kidney or bilateral obstructive uropathy.
DRS 的主要适应证之一是诊断阻塞性尿路/肾病。在标准实践中，这项研究包括评估连续闪烁成像、肾图曲线以及每个肾脏的 TMAX、T1/2 和分肾功能等定量参数。由于分肾功能的相对性质以及 TMAX 和 T1/2 的诊断能力的限制，DRS 被扩展到包括描述绝对肾功能的新的定量参数。本研究旨在评估新的肾效率指数（KEi）的有用性，这是一个新的、内部开发的与肾脏平均清除功能成正比的参数。
该研究纳入了 156 名年龄在 18-84 岁（平均 51 岁）的人群。第一组，即确定新参数的正常值的组，由 20 名健康志愿者组成。第二组由 136 名患者组成，这些患者是根据存档的闪烁成像数据回顾性选择的。“正常率”（62 例阻塞性尿路/肾病低可能性患者中正常结果的百分比）用于评估 KEi 的可靠性。在选择的 74 例单侧功能肾或双侧阻塞性尿路病患者（分肾功能不可靠）中，基于标准和新的 DRS 参数进行了阻塞性尿路/肾病的对比差异分析。
正常值：KEi≥8；KEi 的正常率：95%。与标准 DRS 评估相比，KEi 的应用改变了 1/3 评估肾脏的诊断（92 个肾脏中有 27 个从尿路病变为肾病，4 个相反）。
KEi 能够在不改变标准 DRS 方案的情况下，对绝对肾功能进行可重复的定量评估。其值可以在独立研究之间进行比较（例如，随访检查）。KEi 在单侧功能肾或双侧阻塞性尿路病的情况下纠正了阻塞性尿路/肾病的诊断。
