Kiatpongsan Sorapop, Meng Lesley, Eisenberg Jonathan D, Herring Maurice, Avery Laura L, Kong Chung Yin, Pandharipande Pari V
From the Massachusetts General Hospital Institute for Technology Assessment, 101 Merrimac St, 10th Floor, Boston, MA 02114 (S.K., L.M., J.D.E., M.H., C.Y.K., P.V.P.); Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand (S.K.); Department of Radiology, Massachusetts General Hospital, Boston, Mass (L.L.A., C.Y.K., P.V.P.); and Harvard Medical School, Boston, Mass (C.Y.K., P.V.P.).
Radiology. 2014 Nov;273(2):472-82. doi: 10.1148/radiol.14132629. Epub 2014 Jul 1.
To compare life expectancy (LE) losses attributable to three imaging strategies for appendicitis in adults-computed tomography (CT), ultrasonography (US) followed by CT for negative or indeterminate US results, and magnetic resonance (MR) imaging-by using a decision-analytic model.
In this model, for each imaging strategy, LE losses for 20-, 40-, and 65-year-old men and women were computed as a function of five key variables: baseline cohort LE, test performance, surgical mortality, risk of death from delayed diagnosis (missed appendicitis), and LE loss attributable to radiation-induced cancer death. Appendicitis prevalence, test performance, mortality rates from surgery and missed appendicitis, and radiation doses from CT were elicited from the published literature and institutional data. LE loss attributable to radiation exposure was projected by using a separate organ-specific model that accounted for anatomic coverage during a typical abdominopelvic CT examination. One- and two-way sensitivity analyses were performed to evaluate effects of model input variability on results.
Outcomes across imaging strategies differed minimally-for example, for 20-year-old men, corresponding LE losses were 5.8 days (MR imaging), 6.8 days (combined US and CT), and 8.2 days (CT). This order was sensitive to differences in test performance but was insensitive to variation in radiation-induced cancer deaths. For example, in the same cohort, MR imaging sensitivity had to be 91% at minimum (if specificity were 100%), and MR imaging specificity had to be 62% at minimum (if sensitivity were 100%) to incur the least LE loss. Conversely, LE loss attributable to radiation exposure would need to decrease by 74-fold for combined US and CT, instead of MR imaging, to incur the least LE loss.
The specific imaging strategy used to diagnose appendicitis minimally affects outcomes. Paradigm shifts to MR imaging owing to concerns over radiation should be considered only if MR imaging test performance is very high.
通过使用决策分析模型，比较成人阑尾炎的三种成像策略（计算机断层扫描（CT）、超声检查（US），对于超声检查结果为阴性或不确定的情况随后进行CT检查，以及磁共振成像（MR））导致的预期寿命（LE）损失。
在该模型中，对于每种成像策略，计算20岁、40岁和65岁男性和女性的LE损失，作为五个关键变量的函数：基线队列LE、检查性能、手术死亡率、延迟诊断（漏诊阑尾炎）导致的死亡风险以及辐射诱发癌症死亡导致的LE损失。阑尾炎患病率、检查性能、手术和漏诊阑尾炎的死亡率以及CT的辐射剂量来自已发表的文献和机构数据。通过使用一个单独的器官特异性模型来预测辐射暴露导致的LE损失，该模型考虑了典型腹部盆腔CT检查期间的解剖覆盖范围。进行单因素和双因素敏感性分析，以评估模型输入变异性对结果的影响。
不同成像策略的结果差异极小——例如，对于20岁男性，相应的LE损失分别为5.8天（MR成像）、6.8天（超声和CT联合检查）和8.2天（CT）。这个顺序对检查性能的差异敏感，但对辐射诱发癌症死亡的变化不敏感。例如，在同一队列中，MR成像敏感性至少必须为91%（如果特异性为100%），并且MR成像特异性至少必须为62%（如果敏感性为100%）才能使LE损失最小。相反，超声和CT联合检查导致的LE损失要比MR成像导致的LE损失最小，辐射暴露导致的LE损失需要减少74倍。
用于诊断阑尾炎的特定成像策略对结果的影响极小。仅当MR成像检查性能非常高时，才应考虑因对辐射的担忧而转向MR成像的范式转变。
