多种浸润性疾病可影响小肠，常常导致弥漫性小肠壁增厚。这些浸润性疾病可由多种因素引起，例如免疫细胞或肿瘤细胞的流入或肠壁一层或多层内物质的积累。尽管横截面图像上浸润性疾病的表现可能存在相当大的重叠，但对更具体的辅助影像学特征和临床病理相关性的全面了解可以大大缩小鉴别诊断范围。放射科医生可以帮助综合临床和影像信息并指导后续检查。作者对通常涉及小肠的浸润性疾病进行了全面综述。这些疾病根据其病理生理学特征进行组织，并通过多个说明性案例来增强对这些实体的理解。 CT 和 MRI 是目前评估小肠疾病最常用的成像方式，本综述重点关注这两种方式。提供有关这些浸润性疾病的病理特征、临床表现和影像学表现的详细信息，以帮助放射科医生识别和区分这些疾病。 ©RSNA，2024。

Multiple infiltrative disorders can affect the small bowel, often resulting in diffuse small bowel wall thickening. These infiltrative disorders can manifest owing to various factors such as an influx of immunologic or neoplastic cells or the accumulation of substances within one or more layers of the intestinal wall. Although there can be considerable overlap in the appearances of infiltrative diseases on cross-sectional images, a comprehensive understanding of more specific ancillary imaging features and clinicopathologic correlation can substantially narrow the differential diagnosis. The radiologist can be instrumental in synthesizing the clinical and imaging information and guiding subsequent workup. The authors present a comprehensive review of the infiltrative disorders that commonly involve the small bowel. These disorders are organized on the basis of their pathophysiologic features, with multiple illustrative case examples to enhance understanding of these entities. CT and MRI are currently the most commonly used imaging modalities for evaluating small bowel disorders, and this review is focused on these two modalities. Detailed information regarding the pathologic features, clinical presentation, and imaging findings of these infiltrative disorders is provided to aid radiologists in recognizing and differentiating these conditions. ©RSNA, 2024.