本研究的目的是评估钆匹烯醇（一种高弛豫钆基造影剂）与 0.1 mmol 钆贝酯相比，作为剂量（0.08 mmol/kg 或 0.1 mmol/kg）函数检测小鼠脑转移瘤的能力通过在18只麻醉的Balb/c Nude nu/nu雌性小鼠的左心室中超声引导下心内植入1.105个MDA-MB-231Br细胞来诱导脑转移。在细胞注射后第28±3天，每只小鼠以24小时为间隔接受2次交叉静脉注射，随机选择2剂钆匹烯醇（0.08 mmol/kg或0.1 mmol/kg）和钆苯酯（0.1 mmol/kg），n = 6 只小鼠/组（3 组）。 4 周时，在每次注射之前和之后，在 2.35 T 磁体上进行脑磁共振成像，并使用 3 维 T1 加权高分辨率梯度回波序列。对图像进行盲目随机分析以检测增强病变。根据感兴趣区域信号测量，计算转移瘤与周围健康实质之间的对比度与噪声比。每组 2 只动物，在方案中添加早期时间点（第 22 ± 3 天），以评估作为时间函数的检测灵敏度。最后一次成像后，4 只小鼠通过组织学证实了全脑转移瘤的存在和位置。使用钆匹烯醇后，无论剂量如何，与钆贝酯相比，检测到的转移瘤数量大约是钆贝酯的两倍。与 0.1 mmol/kg 钆苯酯相比，0.08 mmol/kg 和 0.1 mmol/kg 钆匹烯醇检测到的转移瘤的对比度分别高出 2.3 和 3.3 倍（P < 0.0001）。与 0.08 mmol/kg 剂量的钆匹烯醇相比，0.1 mmol/kg 剂量的钆匹烯醇产生的对比度高 1.4 倍（P < 0.02）。在 1 周前成像的一组小鼠中，用钆匹烯醇检测到 2 个转移瘤，而用钆苯酯未检测到。高弛豫性大环钆基造影剂钆匹烯醇在检测脑部增强转移方面具有更高的诊断性能。与钆贝酯相比，在相同剂量 (0.1 mmol/kg) 和低 20% Gd 剂量 (0.08 mmol/kg) 下的噪声比和检测到的转移数量。与 0.08 mmol/kg 剂量相比，0.1 mmol/kg 剂量的钆匹烯醇后肿瘤检出率更高。版权所有 © 2023 作者。由 Wolters Kluwer Health, Inc. 出版

The aim of this study was to evaluate the capacity of gadopiclenol, a high-relaxivity gadolinium-based contrast agent to detect brain metastases in mice as a function of dose (0.08 mmol/kg or 0.1 mmol/kg) compared with gadobenate at 0.1 mmol/kg.Brain metastases were induced by ultrasound-guided intracardiac implantation of 1.105 MDA-MB-231Br cells in the left ventricle of 18 anesthetized Balb/c Nude nu/nu female mice. At day 28 ± 3 after cell injection, each mouse received 2 crossover intravenous injections at 24-hour intervals, randomly selected from 2 doses of gadopiclenol (0.08 mmol/kg or 0.1 mmol/kg) and gadobenate (0.1 mmol/kg) with n = 6 mice/group (3 groups). Brain magnetic resonance imaging sessions were performed at 4 weeks on a 2.35 T magnet with a 3-dimensional T1-weighted high-resolution gradient echo sequence, before and after each injection. Images were blindly and randomly analyzed to detect enhancing lesions. Contrast-to-noise ratio between the metastases and the surrounding healthy parenchyma was calculated, based on region-of-interest signal measurements. In 2 animals per group, an early time point was added to the protocol (day 22 ± 3) to evaluate the sensitivity of detection as a function of time. After the last imaging session, the presence and location of whole-brain metastases were confirmed by histology in 4 mice.After gadopiclenol, approximately twice as many metastases were detected compared with gadobenate, regardless of the dose. Contrast-to-noise ratios of the detected metastases were 2.3 and 3.3 times higher with gadopiclenol at 0.08 mmol/kg and 0.1 mmol/kg, respectively, compared with gadobenate at 0.1 mmol/kg (P < 0.0001). Gadopiclenol at the dose of 0.1 mmol/kg resulted in a 1.4-fold higher contrast compared with gadopiclenol at 0.08 mmol/kg (P < 0.02). In a subset of mice that were imaged 1 week earlier, 2 metastases were detected with gadopiclenol and not with gadobenate.The high-relaxivity macrocyclic gadolinium-based contrast agent gadopiclenol allowed higher diagnostic performance for detecting brain enhancing metastases in terms of contrast-to-noise ratio and number of detected metastases compared with gadobenate, at both equal (0.1 mmol/kg) dose and 20% lower Gd dose (0.08 mmol/kg). Tumor detection was higher after gadopiclenol at the dose of 0.1 mmol/kg compared with 0.08 mmol/kg.Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.