Development of qualitative and quantitative analysis for pancreatic exocrine function : a novel approach using diffusion-weighted MR images

本研究的目的是可视化和量化胰腺实质中水扩散的程度，并无创地评估胰腺不同部位的外分泌功能。首先，通过琼脂幻影实验确定扩散加权MRI的最佳成像参数。应用正常志愿者对确定的基本成像参数进行修正，最终得到弥散加权MRI的最佳成像参数。根据最初的计划，我们打算使用刺激外分泌胰腺腺体和增加胰腺含水量的分泌素来分别评估胰腺外分泌功能（头、体和尾）。然而，促分泌素的销售被取消，促分泌素不能常规使用。我们没有做临床试验，而是做了一个有限的研究。我们评估了正常胰腺在给予分泌素之前和之后的弥散加权MRI。果然，胰腺实质信号改变。事实证明……我们的假设是正确的。由于缺乏分泌素，我们放弃了单独评估胰腺外分泌功能，然后我们评估了表观扩散系数（ADC）值在扩散加权MRI上的实用性。我们比较了正常志愿者和慢性胰腺炎患者胰腺实质的ADC值。结果显示，慢性胰腺炎的ADC值明显低于正常志愿者。此外，我们观察到慢性胰腺炎的ADC值随疾病严重程度而降低。我们认为使用本研究确定的成像参数的弥散加权MRI不仅适用于胰腺，也适用于其他区域。我们将MRI方法应用于其他器官，如肾脏、子宫、卵巢、前列腺，并评估其疗效。因此，弥散加权MRI在鉴别这些器官的肿瘤病变方面发挥了重要作用。这一事实表明我们的方法在诊断各种病变方面具有很大的潜力。少

The aim of this study was to visualize and quantify the degree of water diffusion in the pancreatic parenchyma and to evaluate exocrine function in different part of the pancreas non-invasively.First, optimal imaging parameters of diffusion-weighted MRI were determined by agar phantom experiment. Determined basic imaging parameters were modified by applying normal volunteers, then final optimal imaging parameters of diffusion-weighted MRI was obtained. By an original plan, we intend to use secretin, which stimulate exocrine pancreatic glands and increase pancreatic water content, in order to evaluate pancreatic exocrine function separately (head, body, and tail). However, sale of secretin was canceled and secretin could not be used routinely. Instead of clinical trial, we did a limited study. We evaluated diffusion-weighted MRI of the normal pancreas before and after administration of secretin which we stocked. As expected, pancreatic parenchymal signal change was observed. It was prov … More ed that our hypothesis was right.We gave up evaluating separate pancreatic exocrine function due to lack of secretin, then we evaluate the usefulness of apparent diffusion coefficiency (ADC) value on diffusion-weighted MRI. We compared ADC value of pancreatic parenchyma between normal volunteers and patients with chronic pancreatitis. The result showed that ADC values of chronic pancreatitis were significantly lower than those of normal volunteers. Furthermore, we observed that ADC values of chronic pancreatitis decreased according to disease severity.It is considered that diffusion-weighted MRI using imaging parameters we determined in this study was applied not only in the pancreas but also in other regions. We applied our MRI method to various other organs, such as kidney, uterus, ovary, prostate, and evaluated its efficacy. As a result, diffusion-weighted MRI played an important role in differentiating neoplastic lesions in those organs. This fact reveals that our method has a great potential in diagnosis of various lesions. Less