Gökçe Erkan, Beyhan Murat
Department of Radiology, Faculty of Medicine, Tokat Gaziosmanpasa University, Tokat 60100, Turkey.
World J Radiol. 2022 Aug 28;14(8):256-271. doi: 10.4329/wjr.v14.i8.256.
Salivary gland tumors (SGTs) make up a small portion (approximately 5%) of all head and neck tumors. Most of them are located in the parotid glands, while they are less frequently located in the submandibular glands, minor salivary glands or sublingual gland. The incidence of malignant or benign tumors (BTs) in the salivary glands varies according to the salivary gland from which they originate. While most of those detected in the parotid gland tend to be benign, the incidence of malignancy increases in other glands. The use of magnetic resonance imaging (MRI) in the diagnosis of SGTs is increasing every day. While conventional sequences provide sufficient data on the presence, localization, extent and number of the tumor, they are insufficient for tumor specification. With the widespread use of advanced techniques such as diffusion-weighted imaging, semi-quantitative and quantitative perfusion MRI, studies and data have been published on the differentiation of malignant or BTs and the specificity of their subtypes. With diffusion MRI, differentiation can be made by utilizing the cellularity and microstructural properties of tumors. For example, SGTs such as high cellular Warthin's tumor (WT) or lymphoma on diffusion MRI have been reported to have significantly lower apparent diffusion values than other tumors. Contrast agent uptake and wash-out levels of tumors can be detected with semi-quantitative perfusion MRI. For example, it is reported that almost all of the pleomorphic adenomas show an increasing enhancement time intensity curve and do not wash-out. On quantitative perfusion MRI studies using perfusion parameters such as Ktrans, Kep, and Ve, it is reported that WTs can show higher Kep and lower Ve values than other tumors. In this study, the contribution of advanced MRI to the diagnosis and differential diagnosis of SGTs will be reviewed.
唾液腺肿瘤（SGTs）占所有头颈部肿瘤的一小部分（约5%）。其中大多数位于腮腺，而位于下颌下腺、小唾液腺或舌下腺的情况则较少见。唾液腺中恶性或良性肿瘤（BTs）的发生率因肿瘤起源的唾液腺不同而有所差异。虽然在腮腺中检测到的大多数肿瘤往往是良性的，但在其他腺体中恶性肿瘤的发生率会增加。磁共振成像（MRI）在SGTs诊断中的应用日益广泛。传统序列虽能提供有关肿瘤的存在、定位、范围和数量的充分数据，但对于肿瘤的具体特征来说还不够。随着扩散加权成像、半定量和定量灌注MRI等先进技术的广泛应用，关于恶性或BTs的鉴别及其亚型特异性的研究和数据不断涌现。通过扩散MRI，可以利用肿瘤的细胞密度和微观结构特性进行鉴别。例如，据报道，在扩散MRI上，高细胞密度的沃辛瘤（WT）或淋巴瘤等SGTs的表观扩散值明显低于其他肿瘤。通过半定量灌注MRI可以检测肿瘤的造影剂摄取和洗脱水平。例如，据报道，几乎所有多形性腺瘤的增强时间强度曲线呈上升趋势且无洗脱现象。在使用Ktrans、Kep和Ve等灌注参数进行的定量灌注MRI研究中，据报道WTs的Kep值高于其他肿瘤，而Ve值低于其他肿瘤。在本研究中，将综述先进MRI对SGTs诊断和鉴别诊断的贡献。
