涎腺恶性肿瘤的磁共振成像评价

作者报告２８例经病理检查证实的涎腺区恶性肿瘤的ＭＲＩ表现。通过将这些病变在ＳＥＴ２加权像和ＦＥ成像序列上的影像表现进行对比观察后认为（１）涎腺恶性肿瘤在Ｔ２加权像上的低，中等信号表现具有一定的特征性诊断意义；（２）作为一种有效的方法，ＦＥ序列成像能将肿瘤组织和在Ｔ２加权像上表现为低，中等信号的钙化和纤维组织予以区别，（３）涎腺肿瘤的所在部位和直径大小对其边缘表现和周围邻近正常组织有直接影响。     

Correlation of apparent diffusion coefficient with histopathological parameters of salivary gland cancer

The aim of this study was to correlate the apparent diffusion coefficient (ADC) with histopathological parameters of salivary gland cancer. A retrospective analysis of 44 patients with salivary gland cancer who underwent diffusion-weighted magnetic resonance imaging of salivary glands was performed. The ADC of salivary gland cancer was correlated with pathological tumour type and grade, stage (T stage and N stage), and morphological (perineural spread and location) prognostic parameters. There was a significant difference in ADC values between low–intermediate- and high-grade tumours (P = 0.024), lower T stages (T1, T2) versus higher T stages (T3, T4) (P = 0.001), lower N stages (N0, N1) versus higher N stages (N2, N3) (P = 0.001), and the presence versus absence of perineural spread (P = 0.001). The cut-off ADC values to predict higher-grade, higher T stage, nodal spread, and perineural spread were 0.94, 0.92, 0.94, and 0.98 × 10⁻³ mm²/s, with area under the curve of 0.847, 0.858, 0.900, and 0.798 and accuracy of 75.0%, 75.0%, 75.0%, and 77.3%, respectively. The ADC value is a non-invasive imaging parameter that correlates with histopathological parameters of salivary gland cancer.     

A comparison of imaging techniques with surgical experience in orbital injuries: A prospective study

The aim of the study is to compare the effectiveness of computerised tomography (CT) and magnetic resonance (MR) imaging in diagnosing herniation and entrapment of orbital soft tissues in orbital fractures. 15 consecutive patients with clinical signs and symptoms of medial orbital wall injury were examined with CT and MR. The data were subsequently compared with the findings of the surgical exploration with regard to the extent of the wall fractures, the presence of soft tissue herniation and its entrapment. CT and MR were equally accurate in demonstrating or excluding orbital wall fractures but both modalities slightly underestimated their incidence. CT and MR underestimated the actual incidence of soft tissue herniation and entrapment when compared with the surgical findings but the extent of soft tissue herniation and entrapment were demonstrated more clearly by MR than by CT scanning. MR imaging when available should therefore be used as the initial imaging modality and CT held in reserve for confirmation as positioning in the MR unit is easier and more comfortable for recently injured patients who may well have other injuries.     

MR imaging of tumor-like swelling in the submandibular region

Tumor-like swellings in the submandibular region were evaluated in seven patients with MR imaging. Two cases of pleomorphic adenoma and two of sialoadenitis were selected as examples of submandibular gland lesions, while a plunging ranula, dermoid cyst and lymphadenitis were selected as examples of extraglandular lesions. The pleomorphic adenoma was connected with the remaining gland on T1-weighted images. The sialoadenitis showed changes in the size, signal intensity and homogeneity of the submandibular gland itself. On the other hand, extragland lesions showed zonal interpositions between the lesion and the submandibular gland, which showed either low or high signal intensity on T1-weighted images. On T1-weighted images, the intensity of all of the lesions was either lower than or the same as the normal submandibular gland. On the other hand, all lesions showed higher signal intensity, ranging from slight to very high on T2-weighted images. Sharp margins were seen in all lesions except one sialoadenitis. The sialoadenitis showed inflammatory infiltration into the surrounding tissue. A homogeneous internal pattern was observed in the case of cystic lesions, while an inhomogeneous internal pattern was noted in the pleomorphic adenoma and in the inflammatory lesions. Gd-DTPA enhanced the T1-weighted images in three cases. Pleomorphic adenoma and lymphadenitis were enhanced inhomogeneously, whereas the ranula was not enhanced.     

MR imaging of maxillomandibular lesions

This paper addresses maxillomandibular lesions including cyst, tumor and osteomyelitis in terms of their general features and discusses the use of MR imaging techniques, interpretation of images and their characteristic findings. MR imaging of odontogenic keratocyst improved the visualization of a cystic pattern, regularly thin walls, weak enhancement of cyst walls and inhomogeneous intensity of fluid contents. However, some of them could be misdiagnosed as mixed or solid patterns by non-contrast study alone. Ameloblastoma showed mixed solid and cystic components, irregularly thick walls, papillary projections, and marked enhancement of the walls. In mandibular osteomyelitis, MR imaging could give us more detailed information regarding residual activity of infection and the extent of involvement. MR findings were suggestive to differentiate between tumors and cysts and characterize many cystic entities in the maxillomandibular region.     

腮腺多形性腺瘤的MR诊断

目的:探讨腮腺多形性腺瘤(pleomorphic adenoma,PA)的MRI特征,以提高术前诊断的准确性.方法:回顾性分析2005-2011年间17例经手术后病理检查证实的腮腺多形性腺瘤的MRI平扫加增强表现,其中男6例,女11例:年龄27～70岁,平均50岁.结果:17例患者的17个病灶均为边界清晰肿块,12例有分叶,16例可见包膜.病灶的最大径为1.0～6.3cm,平均2.6cm.与正常肌组织信号相比,肿瘤在T1WI呈等或略低信号,T2WI压脂相呈明显高信号o6例见囊变,2例有钙化影.增强后扫描,17个病灶均有明显延迟强化,其中,4例为均匀强化,13例呈不均匀强化.结论:腮腺单发孤立性病灶,MRI表现为边界清楚、有分叶、可见囊变(或)钙化、有包膜、增强扫描有明显延迟强化特点的肿块,应多考虑PA的可能.     

Imaging features of acinic cell carcinoma: three case reports and a review of the literature

Objectives The purpose of this study was to investigate the imaging characteristics of acinic cell carcinoma in three patients and to present a review of the relevant literature.Methods The tumor site, shape, size, boundary, internal homogeneity and density, and appearance of contrast enhancement were evaluated in three patients with histologically proven acinic cell carcinoma using computed tomography (CT), magnetic resonance (MR), or ultrasonography (US) images. Through a review of the literature, imaging features are summarized.Results Acinic cell carcinoma frequently occurred in the parotid gland. The shape and size were various. The tumor was well-circumscribed and homogeneous if there was no cyst, hemorrhage, or calcification within the tumor. Most lesions showed low and high signal intensities on T1 and T2-weighted MR images, respectively. The tumor was slightly or peripherally enhanced by the contrast medium.Conclusions Acinic cell carcinoma has often been described as a well-circumscribed and homogeneous mass. Even if the tumor in the parotid gland shows benign features on imaging, we should consider acinic cell carcinoma as part of the differential diagnosis.     

Adenocarcinoma in the maxillary sinus: a case report

A case of adenocarcinoma, not otherwise specified, was documented, mainly from a radiographic perspective. The lesion, which occurred in the maxillary sinus, destroyed only a moderate amount of bone considering the tumors large size. There was no sign of necrosis on either computed tomography or magnetic resonance images. This case demonstrated one of the radiographic characteristics of this type of tumor: moderate bone destruction considering the area of the maxillary sinus occupied.