LIPID-POOR ADRENAL MASSES: EVAL W/ DUAL ECHO CHEMICAL SHIFT MR IMAGING

缺乏脂质的肾上腺肿块：使用双回波化学位移 MR 成像进行评估

• 批准号: 7376580
• 负责人: GISELA C MUELLER
• 金额: $ 0.51万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-05 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7376580
• 关键词: adenoma; adrenal glands; fats; ionizing radiation; lipids; neoplasm /cancer

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Tumors of the adrenal glands are common in the general population. As a result of the widespread use of cross sectional imaging techniques, such tumors are often incidentally detected. Adrenal tumors are found in approximately 0.35% - 4.36% of patients who undergo CT imaging for reasons unrelated to the adrenal glands, and the incidence of these tumors increases with age. The majority of adrenal tumors are harmless, and can be left alone. Therefore, it is necessary to characterize these tumors to avoid unnecessary surgery or diagnostic procedures. Benign adrenal tumors will be further referred to as "adrenal adenomas". Many adrenal adenomas can be easily identified on computed tomography without the use of intravenous contrast material, by demonstrating their fat content. Fat is typically seen in benign adrenal tumors and is rare in malignant adrenal lesions. There is, however, a subgroup of adrenal adenomas, the so-called lipid poor adrenal adenomas, whose fat content is too low to be easily detected. Such lesions pose a serious diagnostic problem, especially in patients with history of malignancy. Definitive characterization of such lesions is often achieved with contrast enhanced CT, which involves exposure to ionizing radiation and the risks associated with the use of iodinated contrast medium. Such risks include possible contrast allergy and toxic impairment of marginally functioning kidneys. Iodinated contrast related kidney impairment is kidney function and contrast dose dependent. MR imaging is an effective alternative method for characterizing adrenal masses. It does not involve ionizing radiation or use of intravenous iodinated contrast material. A technique called chemical shift is used in MR imaging to characterize adrenal lesions. This technique exploits imaging the additive and subtracted signal of fat and water in a volume of tissue. While chemical shift MR imaging is as good as non-contrast CT for diagnosing adenomas with high fat content, there is no consensus regarding its utility for characterizing adrenal adenomas with minimal fat content that cannot be characterized by non-contrast CT. This in part is due to the outdated techniques used in older studies addressing this subject. Technical advances in MR imaging with the use of specialized coils for abdominal imaging, and new sequences, allow detection of small amounts of fat in adrenal lesions. A new MRI sequence called the Dual Echo gradient echo, which can be acquired in a single breath-hold, helps eliminate potential sources for imprecise measurements of fat in adrenal tumors, such as misregistration artifacts. So far, no studies have been published to evaluate the accuracy of dual echo chemical shift MR imaging for characterizing lipid poor adrenal lesions. We plan to recruit men and women 18 years of age or older with adrenal masses who have undergone a dedicated CT of the adrenal gland. These patients will undergo an MRI scan, usually 15-20 minute scan without intravenous contrast. If dual echo chemical shift MR imaging proves to be an accurate imaging tool for identifying adrenal adenomas with low fat content that cannot be reliably identified by non-contrast CT, patients will benefit from the advantages of this imaging method including the lack of ionizing radiation, and absence of risk of nephrotoxicity and allergy to iodinated intravenous contrast material.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。肾上腺肿瘤在一般人群中很常见。由于广泛使用的横截面成像技术，这种肿瘤往往是偶然发现。在因与肾上腺无关的原因接受CT成像的患者中，约有0.35% - 4.36%发现肾上腺肿瘤，并且这些肿瘤的发病率随年龄增加而增加。大多数肾上腺肿瘤是无害的，可以单独留下。因此，有必要对这些肿瘤进行定性，以避免不必要的手术或诊断程序。良性肾上腺肿瘤将进一步被称为“肾上腺腺瘤”。许多肾上腺腺瘤可以很容易地确定计算机断层扫描，而无需使用静脉造影剂，通过显示其脂肪含量。脂肪通常见于良性肾上腺肿瘤，在恶性肾上腺病变中很少见。然而，有一个肾上腺腺瘤亚组，即所谓的贫脂肾上腺腺瘤，其脂肪含量太低而不易检测。这种病变造成了严重的诊断问题，特别是在有恶性肿瘤病史的患者中。这类病变的连续性特征通常通过对比增强CT来实现，其涉及暴露于电离辐射和与使用碘化造影剂相关的风险。这些风险包括可能的造影剂过敏和毒性损害的边缘功能的肾脏。碘造影剂相关肾损害具有肾功能和造影剂剂量依赖性。MR成像是一种有效的替代方法来表征肾上腺肿块。它不涉及电离辐射或使用静脉内碘化造影剂。一种称为化学位移的技术用于MR成像以表征肾上腺病变。该技术利用对一定体积组织中脂肪和水的相加和相减信号进行成像。虽然化学位移MR成像在诊断高脂肪含量腺瘤方面与非增强CT一样好，但对于非增强CT无法表征的脂肪含量极低的肾上腺腺瘤，其实用性尚未达成共识。这部分是由于在解决这个问题的旧研究中使用的过时技术。磁共振成像技术的进步，使用专门的线圈腹部成像，新的序列，允许检测少量的脂肪肾上腺病变。一种新的MRI序列称为双回波梯度回波，可以在单次屏气中采集，有助于消除肾上腺肿瘤中脂肪测量不精确的潜在来源，如配准不良伪影。到目前为止，还没有研究已经发表，以评估双回波化学位移磁共振成像的准确性，表征脂质缺乏肾上腺病变。我们计划招募18岁或以上患有肾上腺肿块的男性和女性，他们已经接受了肾上腺的专用CT。这些患者将接受MRI扫描，通常扫描15-20分钟，无需静脉造影剂。如果双回波化学位移磁共振成像被证明是一种准确的成像工具，用于识别非造影CT无法可靠识别的低脂肪含量肾上腺腺瘤，患者将受益于这种成像方法的优点，包括缺乏电离辐射，没有肾毒性和对碘化静脉造影剂过敏的风险。