Visual interpretation of ¹²³I-ioflupane SPECT images has high diagnostic accuracy for differentiating parkinsonian syndromes (PS), from essential tremor and probable dementia with Lewy bodies (DLB) from Alzheimer disease. In this study, we investigated the impact on accuracy and reader confidence offered by the addition of image quantification in comparison with visual interpretation alone. Methods: We collected 304 ¹²³I-ioflupane images from 3 trials that included subjects with a clinical diagnosis of PS, non-PS (mainly essential tremor), probable DLB, and non-DLB (mainly Alzheimer disease). Images were reconstructed with standardized parameters before striatal binding ratios were quantified against a normal database. Images were assessed by 5 nuclear medicine physicians who had limited prior experience with ¹²³I-ioflupane interpretation. In 2 readings at least 1 mo apart, readers performed either a visual interpretation alone or a combined reading (i.e., visual plus quantitative data were available). Readers were asked to rate their confidence of image interpretation and judge scans as easy or difficult to read. Diagnostic accuracy was assessed by comparing image results with the standard of truth (i.e., diagnosis at follow-up) by measuring the positive percentage of agreement (equivalent to sensitivity) and the negative percentage of agreement (equivalent to specificity). The hypothesis that the results of the combined reading were not inferior to the results of the visual reading analysis was tested. Results: A comparison of the combined reading and the visual reading revealed a small, insignificant increase in the mean negative percentage of agreement (89.9% vs. 87.9%) and equivalent positive percentages of agreement (80.2% vs. 80.1%). Readers who initially performed a combined analysis had significantly greater accuracy (85.8% vs. 79.2%; P = 0.018), and their accuracy was close to that of the expert readers in the original studies (range, 83.3%–87.2%). Mean reader confidence in the interpretation of images showed a significant improvement when combined analysis was used (P < 0.0001). Conclusion: The addition of quantification allowed readers with limited experience in the interpretation of ¹²³I-ioflupane SPECT scans to have diagnostic accuracy equivalent to that of the experienced readers in the initial studies. Also, the results of the combined reading were not inferior to the results of the visual reading analysis and offered an increase in reader confidence.

¹²³ I-ioflupane SPECT图像的视觉解释具有很高的诊断准确性，可将帕金森氏综合征（PS）与原发性震颤和可能的痴呆与阿尔茨海默氏病的路易体（DLB）区分开。在这项研究中，我们调查了图像量化与单独视觉解释相比对准确性和读者信心的影响。方法：我们收集了304 ¹²³来自3个试验的I-ioflupane图像，包括具有PS，非PS（主要是震颤），可能的DLB和非DLB（主要是阿尔茨海默病）的临床诊断的受试者。在根据正常数据库对纹状体结合率进行定量之前，用标准化参数重建图像。图片由5位在^123年以前经验有限的核医学医师进行了评估碘氟烷的解释。在至少间隔1个月的2个读数中，读者可以单独进行视觉解释，也可以进行组合阅读（即可以使用视觉数据和定量数据）。要求读者评价他们对图像解释的信心，并判断扫描是否容易阅读。通过将图像结果与真相标准（即随访诊断）进行比较，通过测量一致性的正百分比（相当于敏感性）和阴性的负百分比（相当于特异性）来评估诊断的准确性。测试了组合阅读结果不逊于视觉阅读分析结果的假设。结果：合并阅读和视觉阅读的比较显示，协议的平均负百分比（89.9％比87.9％）和同等的协议正百分比（80.2％比80.1％）有很小的微不足道的增加。最初进行合并分析的读者的准确率要高得多（85.8％vs. 79.2％；P = 0.018），其准确度与原始研究的专家水平相近（范围为83.3％–87.2％）。当使用组合分析时，平均读者对图像解释的置信度显示显着改善（P <0.0001）。结论：量化的增加使读者在¹²³解释方面的经验有限I-ioflupane SPECT扫描的诊断准确性与初步研究中经验丰富的读者相当。同样，合并阅读的结果也不逊于视觉阅读分析的结果，并增加了读者的信心。