Danet Ioana-Maria, Semelka Richard C, Leonardou Polytimi, Braga Larissa, Vaidean Georgeta, Woosley John T, Kanematsu Masayuki
Department of Radiology, University of North Carolina at Chapel Hill, CB 7510, Chapel Hill, NC 27599-7510, USA.
AJR Am J Roentgenol. 2003 Sep;181(3):809-17. doi: 10.2214/ajr.181.3.1810809.
The purpose of our study was to identify the spectrum of MRI appearances of untreated liver metastases from different primary origins.
Over a period of 52 months, we used our clinical information system to retrospectively identify the first MRIs obtained in 165 consecutive patients who had untreated liver metastases. All patients had histologic confirmation of the primary tumor. Liver metastases were confirmed at histologic examination, on imaging, or at clinical follow-up. MR sequences used included T1-weighted spoiled gradient-echo, T2-weighted half-Fourier acquisition single-shot turbo spin-echo, and serial gadolinium-enhanced spoiled gradient-echo imaging. Size, signal intensity characteristics, and pattern of enhancement of the metastases on MRIs were evaluated by two radiologists in consensus. Lesions were categorized by size: smaller than 1.5 cm, between 1.5 and 3.0 cm, and larger than 3.0 cm.
A total of 516 metastases (size range, 5-120 mm; mean, 28 mm) were assessed. Fifty-nine patients had hypervascular lesions, and 106 patients had hypovascular lesions. A significant difference in proportion of tumor vascularity was observed between the primary tumors described as classically hypervascular and those described as classically hypovascular (chi-square test for proportions of 70.8, p < 0.0001). The most common pattern was peripheral ring (72% of patients) seen on the arterial dominant phase images, with incomplete central progression (63%) seen on the delayed phase images. A hypointense ring seen in the periphery of the tumor during the delayed phase was the most common appearance in hypervascular metastases (27% patients) and was particularly conspicuous in patients with neuroendocrine and carcinoid tumors. Perilesional enhancement was common (47%), mostly seen in hypovascular metastases (92%). Generally, large lesions tended to show a peripheral ring or heterogeneous enhancement, and small lesions showed homogeneous enhancement.
MRI allows the identification of a wide spectrum of appearances of untreated liver metastases. The extent and pattern of enhancement of various histologic types of tumor are depicted on MRI.
我们研究的目的是确定不同原发灶来源的未经治疗的肝转移瘤的磁共振成像（MRI）表现谱。
在52个月的时间里，我们利用临床信息系统回顾性地确定了165例连续患有未经治疗的肝转移瘤患者首次进行的MRI检查结果。所有患者的原发肿瘤均经组织学证实。肝转移瘤通过组织学检查、影像学检查或临床随访得以确诊。所使用的MR序列包括T1加权扰相梯度回波序列、T2加权半傅里叶采集单次激发快速自旋回波序列以及系列钆增强扰相梯度回波成像。两名放射科医生共同评估MRI上转移瘤的大小、信号强度特征及强化方式。病变按大小分类：小于1.5 cm、1.5至3.0 cm以及大于3.0 cm。
共评估了516个转移瘤（大小范围为5 - 120 mm；平均28 mm）。59例患者有高血供病变，106例患者有低血供病变。在被描述为典型高血供的原发肿瘤和典型低血供的原发肿瘤之间，观察到肿瘤血供比例存在显著差异（比例的卡方检验值为70.8，p < 0.0001）。最常见的模式是在动脉期优势图像上出现周边环形强化（72%的患者），在延迟期图像上出现中央不完全强化（63%）。延迟期肿瘤周边出现低信号环是高血供转移瘤最常见的表现（27%的患者），在神经内分泌肿瘤和类癌患者中尤为明显。瘤周强化很常见（47%），大多见于低血供转移瘤（92%）。一般来说，大的病变倾向于表现为周边环形或不均匀强化，小的病变表现为均匀强化。
MRI能够识别未经治疗的肝转移瘤的多种表现。MRI可描绘出各种组织学类型肿瘤的强化范围和方式。
