A Correlational Study of THz and MRI Hydration Mapping in In vivo Skin Burns

描述(申请人提供)：这项建议旨在比较太赫兹(THz)反射率图和MRI水化指标，特别是T2松弛时间的变化，以验证组织水分含量作为THz烧伤成像的主要对比机制，并研究THz图像中部分和全层烧伤病理生理的差异，以早期和准确地诊断创面严重程度。烧伤程度最常通过视觉和触觉评估来检查，仅有50%-70%的病例预后成功。几个烧伤治疗中心已经实施了激光多普勒成像(LDI)作为补充诊断；然而，该程序依赖于血液灌注量的测量，这可能是热损伤后立即糟糕的标志。我们小组在大鼠身上获得的初步活体结果表明，OU非侵入性太赫兹成像系统快速、准确地生成烧伤的皮肤反射率图像；在受伤的最初几个小时内清楚地描绘出烧伤创面区域和烧伤严重程度。 烧伤诱导导致的组织光学性质的变化在受伤和未受伤的区域之间形成了对比，这在后天获得的反射太赫兹图像中很明显。然而，烧伤区域周围的太赫兹反射率值通常在空间和时间上是可变的，这些发现并不总是与组织学分析相关联。鉴于其在组织特异性和对水的敏感性方面的优势，MRI可以作为一种辅助工具来进一步了解和证实烧伤病理生理图中似乎是水合的变化，并加强医学THz成像作为一种快速检测烧伤创面的护理点技术的临床潜力。最近在活体大鼠皮肤上进行的T2加权多层多回波(T2w MSME)7Tesla MR和THz平行成像研究表明，这两种方法都可以用于定位烧伤区域和检测组织中的水运动；T2弛豫时间，一种常见的水化磁共振指标，以及烧伤区域的THz反射率测量在烧伤诱导后增加。这些初步结果似乎支持了MRI测量组织水分含量的敏感性和特异性的充分性，以及使用该模式来验证太赫兹烧伤成像对皮肤烧伤的急性诊断和水肿性反应监测的水合传感能力。这项研究将从试点、并行MRI和THz活体皮肤成像实验开始，为大规模的活体大鼠研究提供必要的基础。第二年将包括对20只活鼠的广泛研究，样本大小基于幂为0.9、可信区间为0.05的配对t检验。这些模式之间的相关性将通过联合注册和组织学分析进行评估。

DESCRIPTION (provided by applicant): This proposal aims to compare terahertz (THz) reflectivity maps and MRI hydration indicators, specifically changes in T2 relaxation times, to validate tissue water content as the dominant contrast mechanism in THz burn imaging and study differences in THz imagery of partial and full thickness burn pathophysiology for early and accurate diagnosis of wound severity. Burn extent is most often examined by visual and tactile assessment with successful prognosis in only 50-70% of cases. Several burn treatment centers have implemented Laser Doppler Imaging (LDI) as a complementary diagnostic; however, this procedure relies on measurements of blood perfusion which can be a poor marker immediately following thermal insult. Preliminary in vivo results acquired by our group in rats suggest that ou non-invasive THz imaging system rapidly and accurately generates skin reflectivity imagery of burns; clearly delineating burn wound zones and burn severity within the first few hours of injury. Resultant changes in the optical properties of tissue by burn induction create contrast between injured and uninjured areas evident in acquired reflective THz images. However, THz reflectivity values around the burn region may often be spatially and temporally variable, and these findings do not always correlate with histological analysis. Given its advantages in tissue specificity and water sensitivity, MRI can be used as a supplementary tool to further understand and substantiate what appear to be hydration changes in THz maps of burn pathophysiology and reinforce the clinical potential of medical THz imaging as a point-of-care technology for rapid detection of burn wounds. Recent T2 weighted multi slice multi echo (T2w MSME) 7 Tesla MR and THz parallel imaging studies in in vivo rat skin demonstrate that both modalities can be used to localize the burn region and detect water movement in tissue; T2 relaxation times, a common MR index of hydration, and THz reflectivity measurements of the burn area increase following burn induction. These preliminary results appear to support the sufficiency of the sensitivity and specificity of MRI for measuring tissue water content and the use of this modality to verify the hydration sensing capabilities of THz burn imaging for acute diagnosis of skin burns and monitoring of edematous responses. This study will commence with pilot, parallel MRI and THz in vivo skin imaging experiments, providing the necessary groundwork for large scale in vivo rat studies. Year 2 will encompass extensive work on 20 live rats, a sample size based on a paired t-test with a power of 0.9 and a confidence interval of 0.05. Correlations between these modalities will be assessed by co-registration with histological analysis.