Dual Energy CT Evaluation of Airway Inflammation

描述（由申请人提供）：本提案旨在通过使用双能量计算机断层扫描（DECT）直接测量碘化造影剂给药后支气管壁增强，提供气道炎症的独特、定量、功能性生物标志物。我们假设的关键是炎症导致支气管动脉充血这一公认的事实，以前需要侵入性血管造影术或复杂的实验室技术很少使用。获得性和遗传性的大量疾病导致慢性气道炎症，对于这些疾病的诊断和特别是管理代表重要和常见的临床挑战。虽然高分辨率CT在确定和监测这些疾病中起着重要作用，但迄今为止，CT解释完全依赖于形态学评估，并且通常是主观的。我们提出了一种新的诊断模式，强调定量，功能评估的程度和严重程度的气道炎症的最终目的是应用这种方法的广泛的原因气道炎症-具有重要的意义，准确地评估常规治疗，以及重要的是提供一个生物标志物的潜在的新的治疗方法。该提案的真正创新之处在于使用了最近推出的双能CT扫描仪，该扫描仪现在能够在两个不同的能量水平上同时采集CT数据，从而能够通过材料独特的化学成分区分材料。这包括单独绘制组织内碘分布的特定能力，从而定量测量节段和亚节段气道壁内的对比度增强。为了验证我们的假设，我们建议研究有记录的鸟分枝杆菌复合体（MAC）肺病患者作为慢性气道炎症相关疾病的适当模型。MAC越来越普遍，并与相当大的发病率和死亡率。虽然诊断标准已经明确，但治疗适应症仍然存在很大争议，需要延长3-4种药物治疗方案，导致许多副作用。最后，管理治疗的指导方针已被证明是特别有问题的，缺乏具体和可靠的定量，功能标记。具体而言，对于本研究，我们建议评估总共60例MAC患者，其中30例将需要治疗，使用连续DECT代替常规获得的随访CT检查，目的是记录DECT为慢性气道炎症患者提供新型生物标志物的潜力。

DESCRIPTION (provided by applicant): The purpose of this proposal is to provide a unique, quantitative, functional biomarker of airway inflammation by directly measuring bronchial wall enhancement following iodinated contrast administration using dual-energy computed tomography (DECT). Key to our hypothesis is the well established fact that inflammation leads to bronchial arterial hyperemia previously requiring either invasive angiography or sophisticated laboratory techniques rarely utilized. A large number of diseases, both acquired and inherited, result in chronic airway inflammation, conditions for which diagnosis and especially management represent important and common clinical challenges. Although high resolution CT plays an important role in establishing and monitoring these diseases, to date, CT interpretation has exclusively relied on morphologic assessment and is often subjective. We propose a new diagnostic paradigm by emphasizing quantitative, functional assessment of the extent and severity of airway inflammation with the ultimate aim of applying this approach to a wide range of causes of airway inflammation - with important implications for accurately assessing both routine treatment as well as importantly providing a biomarker for potential new therapeutic approaches . The truly innovative aspect of this proposal is the use of recently introduced dual energy CT scanners that now enable the simultaneous acquisition of CT data at two different energy levels allowing differentiation of materials by their unique chemical composition. This includes the specific ability to separately map the distribution of iodine within tissues, and hence quantitatively measure contrast enhancement within segmental and subsegmental airway walls. To validate our hypothesis, we propose to study patients with documented Mycobarterial avium complex (MAC) lung disease as an apt model of conditions associated with chronic airway inflammation. MAC is increasingly prevalent and is associated with considerable morbidity and mortality. While criteria for diagnosis are well defined, indications for treatment remain highly controversial, requiring a prolonged 3-4 drug regimen causing numerous side-effects. Finally, guidelines for managing therapy have proved especially problematic, lacking specific and reliable quantitative, functional markers. For this study, specifically, we propose to evaluate a total of 60 patients with MAC, 30 of whom will require therapy, with sequential DECT's obtained in place of routinely acquired follow-up CT exams, with the intent to document the potential of DECT to provide a novel biomarker in patients with conditions causing chronic airway inflammation.