Allbery S M, Chaljub G, Cho N L, Rassekh C H, John S D, Guinto F C
Department of Radiology, University of Texas Medical Branch, Galveston 77550-0465, USA.
Radiographics. 1995 Nov;15(6):1311-27. doi: 10.1148/radiographics.15.6.8577959.
Magnetic resonance (MR) imaging is useful in evaluating the wide spectrum of diseases that cause nasal masses. MR imaging is most helpful in (a) defining tumor margins and possible intracranial extension and (b) differentiating tumor (which has intermediate, heterogeneous signal intensity on T2-weighted images) from concurrent postobstructive sinusitis and other infectious or inflammatory masses (which have high, homogeneous signal intensity on T2-weighted images if the secretions are well hydrated). The analysis becomes more complicated in cases with desiccated and mixed composition secretions. MR imaging also allows characterization of very vascular tumors, which show flow voids or marked enhancement. Low signal intensity on T1-weighted images and marked low signal intensity on T2-weighted images are characteristic of fungal sinusitis, and fat within a nasal mass indicates a dermoid or epidermoid cyst. Idiopathic midline granuloma, Wegener granulomatosis, and "cocaine nose" manifest as predominantly destructive midline masses. Despite the advantages of MR imaging, computed tomography remains the preferred imaging modality for evaluating nasal masses that contain calcification or originate from bone or cartilage.
磁共振（MR）成像在评估引起鼻腔肿块的多种疾病方面很有用。MR成像在以下方面最有帮助：（a）确定肿瘤边界和可能的颅内扩展，以及（b）将肿瘤（在T2加权图像上具有中等、不均匀信号强度）与并发的阻塞性鼻窦炎及其他感染性或炎性肿块（如果分泌物充分水化，在T2加权图像上具有高、均匀信号强度）区分开来。在分泌物干燥且成分混合的情况下，分析会变得更加复杂。MR成像还可以对血管丰富的肿瘤进行特征性描述，这些肿瘤表现为血流空洞或明显强化。T1加权图像上的低信号强度和T2加权图像上明显的低信号强度是真菌性鼻窦炎的特征，鼻腔肿块内的脂肪表明为皮样囊肿或表皮样囊肿。特发性中线肉芽肿、韦格纳肉芽肿和“可卡因鼻”主要表现为破坏性中线肿块。尽管MR成像有诸多优点，但计算机断层扫描仍是评估含有钙化或起源于骨或软骨的鼻腔肿块的首选成像方式。
