MR涎管造影初探

目的：估价ＭＲ涎管系统成像的技术和临床应用。材料与方法：用ＭＲ重Ｔ２加权技术加特别长的ＴＥ，回波时间７５０毫秒，采用脂肪抑制，厚层扫描，快速采集。检查了１７例，其中１４例无症状者，３例可疑涎管异常者。结果：无症状者１４例均清楚显示腮腺主导管。颌下腺主导管展示，但欠连续。３例可疑异常者中，１例示左颌下腺导管受压移位，手术证实为鳞癌。其余２例未见异常征象。结论：ＭＲ涎管造影能成功地显示腮腺和颌下腺导管系统，是一种非侵袭性检查方法，经进一步提高质量后相信有临床实际应用价值。     

干燥综合征的腮腺MRI表现

目的探讨干燥综合征患者的腮腺MRI表现。方法对7例临床确诊为干燥综合征的患者行3.0TMRI检查,MRI扫描序列包括平扫轴位T1WI、T2脂肪抑制序列、冠状位及腮腺导管水成像序列,对各采集图像进行分析。结果7例患者双侧腮腺均有不同程度肿大,与正常腮腺MRI信号对比,7例患者的腮腺T1WI均表现为信号减低,并见弥漫分布大小不等点状、结节状低信号影,T2WI表现为腮腺信号增高,伴有弥漫分布的点状、结节状高信号影,T2WI冠状位压脂序列除能显示腮腺形态、信号改变外,另外能很好显示颈部淋巴结增大情况,本组7例均出现颈部多发淋巴结肿大,于T2WI压脂序列上呈较高信号。腮腺水成像显示,本组中1例表现为双侧腮腺主导管、分支导管管腔串珠状扩张及末梢导管球囊状扩张,6例仅表现为末梢导管点状、球囊状扩张,而主导管及分支导管形态正常。结论 MRI能很好的显示干燥综合征的腮腺形态和信号的改变,腮腺导管水成像是利用唾液天然对比剂功能而进行的一种无创性涎管造影检查,能很直观反映腮腺各级导管扩张的情况,从而能帮助临床对患者腮腺唾液的分泌及排空功能做一个很好的评估。     

3.0T磁共振腮腺管水成像对腮腺疾病的临床应用

目的:探讨3.0T磁共振水成像(MRS)对腮腺疾病导管显像的临床应用,结合手术及病理结果,评价其对腮腺疾病诊断与治疗的指导意义.方法:对25例临床诊断腮腺疾病患者进行常规扫描后,利用IR-FSE序列进行腮腺导管成像,然后给患者含服VitC于3min后再次扫描,对获得图像按腮腺管及其分支显示效果进行分级及效果评价.结果:25例腮腺病变中,腮腺炎6例,腮腺脓肿1例,腮腺管结石4例,多形性腺瘤10例,腺淋巴瘤2例,T细胞淋巴瘤1例.粘液表皮样癌1例.MRS结果显示,11例非肿瘤性病变中,导管系统变形者8例,占72.7％;14例肿瘤性病变中,导管系统变形者12例,占85.7％.导管系统变形多以2级以上导管改变为主.结论:IR-FSE序列MR腮腺导管成像能较好显示腮腺管及其分支受压、扩张、移位、破坏等征象,对腮腺疾病诊断与治疗具有重要指导意义.     

3．OT磁共振腮腺管水成像对腮腺疾病的临床应用

目的：探讨3．0T磁共振水成像（MRS）对腮腺疾病导管显像的临床应用．结合手术及病理结果,评价其对腮腺疾病诊断与治疗的指导意义。方法：对25例临床诊断腮腺疾病患者进行常规扫描后,利用IR-FSE序列进行腮腺导管成像。然后给患者含服VitC于3min后再次扫描。对获得图像按腮腺管及其分支显示效果进行分级及效果评价。结果：25例腮腺病变中．腮腺炎6例,腮腺脓肿l例。腮腺管结石4例,多形性腺瘤10例．腺淋巴瘤2例,T细胞淋巴瘤1例,粘液表皮样癌l例。MRS结果显示,11例非肿瘤性病变中,导管系统变形者8例,占72．7％;14例肿瘤性病变中。导管系统变形者12例,占85．7％。导管系统变形多以2级以上导管改变为主。结论：IR-FSE序列MR腮腺导管成像能较好显示腮腺管及其分支受压、扩张、移位、破坏等征象,对腮腺疾病诊断与治疗具有重要指导意义。     

正常骶髂关节软骨MRI成像分析

目的 探讨MRI显示正常骶髂关节软骨的最佳序列.方法 收集40例健康志愿者80侧骶髂关节软骨MRI扫描资料,其中男28例,女12例,年龄18~45岁,平均为29.36岁.均使用Philips Intera Achieva 1.5T 双梯度扫描仪,扫描序列包括轴位T1WI、T2WI、STIR、3D-WATS及斜冠状位T2WI.由2名资深医生对每侧骶髂关节软骨在不同序列显示情况进行分组评价,分为清晰、基本清晰、不清晰3组,统计处理各组间显示率差异.结果 40例健康志愿者80侧骶髂关节软骨在T1WI、T2WI、STIR、3D-WATS序列均可不同程度的显示,其中清晰组在各个序列的显示率为18.75%、0.00%、8.75%、93.75%,其中3D-WATS与T1WI、T2WI、STIR序列比较P＜0.05;T1WI、T2WI、STIR序列各组间比较P＞0.05.结论 3D-WATS序列是显示骶髂关节软骨的最佳序列.     

MR腮腺管成像不同序列的比较研究

目的：探讨几种MR成像序列对显示腮腺、导管的优劣以及对腮腺疾病导管系统的变化进行观察。方法：对25例健康志愿者和10例腮腺疾病患者进行腮腺区域常规MRI扫描后,利用IR-FSE、3DFRFSE-XL3DCUBET2WI3种序列进行腮腺管水成像,对得到的图像进行后处理,然后对其各自显示腮腺导管及其分支的效果进行评比。结果：IR-FSE显示健康正常志愿者腮腺导管22例,3D-FRFSEXL为25例,3D-CUBE-T2WI为24例,3种序列显示腮腺疾病患者导管的例数分别为8侧、10例、8例。IR-FSE、3D-FRFSE—XL背景组织较少,IR-FSE可显示主导管和二级导管,3D-FRFSEXI。经重建后可显示主导管、二级导管和三级导管且导管显示平滑,图像信噪比高,3D-T2W1经重建后可显示主导管和二级导管,且可显示腮腺导管腺体的关系以及腮腺病变侵及腮腺、导管的范围。结论：三种序列均能较好地显示腮腺导管,但各自有优势,对腮腺疾病的诊断具有重要意义。     

不同射频线圈应用于三维磁共振涎管造影的对比研究

目的 通过对比研究探讨最适合于三维薄层磁共振涎管造影的射频线圈.方法 50名无涎腺病变志愿者,采用重T2加权FSE序列,固定TR、TE和其他扫描参数,依次应用头线圈、头颈联合线圈、C3表面线圈和SENSE-FLEX-M线圈进行扫描,对涎管的三维磁共振造影图像进行评分,计算涎管与背景组织间的对比噪声比(CNR),比较不同线圈组涎管的得分和CNR之间有无统计学差异.结果 不同线圈组的磁共振涎管造影图像的得分和CNR之间具有显著性差异(P<0.01).在腮腺管的显示上,头线圈组的得分和CNR显著低于其他各组,头颈联合线圈组的得分和CNR低于C1表面线圈组和FLEX-M线圈组(P<0.05),C3表面线圈组和FLEX-M线圈组之间无显著性差异(P>0.05).在颌下腺管的显示上,头线圈组的得分和CNR显著低于其他各组(P<0.01),其余各组之间无显著性差异(P>0.05).结论 在Philips Achieva 1.5T磁共振机上行三维重T2加权FSE磁共振涎管造影,应用SENSE-FLEX-M线圈既能保证获得高质量的涎管影像,又不会增加检查的复杂性,是最佳选择.     

3D-FSE-T_2WI腮腺MR涎管成像

作者旨在评估磁共振快速自旋回波(FSE)涎管成像对正常及病变腮腺的诊断准确性。健康志愿者8例,腮腺疾病患者18例(包括腮腺肿瘤3例,涎石病6例,Sjogren病4例,非特异性或慢性腮腺炎4例,外伤1例)。所有志愿者及患者均在增强扫描前行MR涎管成像。成像方法为3D-FSE重T_2加权像加脂肪抑制技术。FOV200mm,30～50层,1～1.2mm层厚,TR/TE6000/500ms,矩阵为256×256或256×512,检查时间6min左右。在独立工作站上重建MIP图像。此外,均有2D-FSE T_2WI,腮腺患者还     

磁共振胰胆管成像序列的比较研究

目的：比较磁共振胰胆管成像（MRCP）不同序列对胰胆管树的显示能力及其临床应用。材料和方法：对24例正常成年志愿者及30例胰胆管梗阻性疾病患者行FSE、FSE—XL和SSFSEMRCP检查，并对各扫描序列的胰胆管显示情况进行分析。结果：FSE—XL和SSFSE扫描序列对胰胆管及病变部位的显示明显优于常规FSE扫描序列，SSFSE又优于FSE—XL扫描序列。SSFSE扫描序列能充分显示正常胰胆管树，对胰胆管梗阻性疾病的检出率也较高。结论：SSFSE扫描序列与能多方位观察胰胆管情况的FSE—XL扫描序列联合应用，可明显提高对胰胆管梗阻性疾病的检出率。     

磁共振腮腺管成像技术探讨

目的 :通过优化和改进磁共振腮腺管造影技术 ,更清晰显示腮腺导管及其分支 ,提高腮腺管显示效果。方法 :采用几种序列显示 2 3例腮腺部位病变患者的腮腺管 ,然后给患者含服 2 0 0mg维生素C ,于服药后 3min和 10min分别再次扫描 ,将所获图像按腮腺管及其分支显示效果进行分级 ,比较各种序列及其服药前后的显示效果。结果 :IR FSE序列较传统FSE扫描腮腺管的显示效果明显提高 (P <0 .0 5 ) ,而SS FSE和SS IR FSE的成像时间虽然极短 ,但其分辨率及信噪比相对较差。服药后腮腺管的显示效果有一定程度的提高但不显著 (P >0 .0 5 )。结论 :在相同的扫描参数下 ,超长TR和TE的IRFSE脂肪抑制序列较其它序列能更好的显示腮腺管及其分支     

MR sialography: the effect of a sialogogue and ductal occlusion in volunteers

MR sialography using heavily T(2) weighted projection techniques relies upon saliva for image contrast, and the visualization of normal ducts is often limited. Methods used to increase the volume of intraductal saliva during imaging in order to improve duct visualization have not been previously evaluated. The effect of a sialogogue and passive ductal occlusion on the ability to visualize the main and intraglandular salivary gland ducts during MR sialography was investigated. Three-dimensional (3D) T(2) weighted MR sialograms were obtained from 12 healthy volunteers with and without the combined use of a sialogogue and passive ductal occlusion pad adjacent to the parotid duct orifice on one side. Two radiologists (in consensus) subjectively evaluated ductal visualization and image artefacts on the resulting blinded maximum intensity projections. The results demonstrate that main duct visualization was significantly improved (p<0.00001) by this technique, with no significant change seen in image artefacts. Although an improvement in intraglandular duct visualization was noted, this was not statistically significant (p = 0.05). Thus, the use of a sialogogue and passive ductal occlusion improves visualization of the main parotid duct in volunteers undergoing MR sialography. Further optimization and evaluation of this approach should lead to improvements in the MR sialography examination of patients.     

3D T2-weighted fast spin-echo MRI sialography of the parotid gland

The diagnostic value of 3D T2-weighted MRI sialography and 2D T2-weighted fast spin-echo (FSE) images for delineation of the normal duct system and characterisation of parotid gland duct pathology was compared in a prospective study. We studied eight healthy volunteers and 18 patients with pathology of the parotid gland (tumours in 3, sialolithiasis in 6, Sjögren's disease in 4, recurrent or chronic parotitis in 4, post-traumatic stricture of the main parotid duct in 1). A heavily T2-weighted 3D FSE sequence was compared with a conventional 2D T2-weighted FSE sequence. The normal main parotid duct was always visible on 3D sialography and seen in 68 % of the 2D T2-weighted FSE studies. The diagnostic reliability of both sequences for diagnosis of luminal concretions in sialolithiasis and dilatation of the duct in duct stricture or chronic parotitis was equal, although slight intraglandular dilatation was appreciated only on 3D sialography. Extraductal pathology resulting in obstruction or displacement of ducts was better characterised on 2D T2-weighted images. However, 3D MRI sialography offered the advantage of postprocessing with overview images and multiple maximum-intensity projection images in any plane.     

MR sialography using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences.

We describe our preliminary experience with the half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences for MR imaging of the salivary gland ducts. In the majority of patients, the main parotid and/or submandibular gland ducts and large branches within the glands were detectable on MR images obtained in 2 seconds per section and within 3 minutes for the entire examination. MR sialography using HASTE sequences can be combined with conventional MR studies for the salivary glands.     

Comparative study of MR sialography and digital subtraction sialography for benign salivary gland disorders

BACKGROUND AND PURPOSE: MR sialography has become an alternative imaging technique for ductal salivary gland diseases. We compared the diagnostic accuracies of MR sialography and digital subtraction sialography in patients with successful completion of both examinations and benign salivary gland disorders. METHODS: In a prospective study, we attempted to examine salivary glands in 80 patients with clinically suspected diagnoses of sialadenitis and/or sialolithiasis. Each patient underwent digital subtraction sialography and MR sialography. MR sialography was obtained with a T2-weighted single-shot turbo spin-echo sequence (TR/TE 2800/1100 msec, acquisition time 7 seconds), with use of a quadrature head coil. Final diagnoses were confirmed by clinical follow-up and results of biopsy (n = 9) or surgery (n = 19). RESULTS: Failure rate was 5% (four of 80) for MR sialography and 14% (11 of 80) for digital subtraction sialography. Eighty-one salivary glands (48 parotid, 33 submandibular) in 65 patients were successfully visualized with both modalities. MR sialography depicted the main ductal system and first- and second-order branches, whereas digital subtraction sialography was able to depict third-order branches. Sensitivity and specificity to diagnose chronic sialadenitis were 70% and 98% with MR and 96% and 100% with digital subtraction sialography. MR sialography enabled diagnosis of sialolithiasis with a sensitivity of 80% and a specificity of 98% versus 90% and 98% for each with digital subtraction sialography. CONCLUSION: MR sialography with a heavily T2-weighted sequence is highly successful in the noninvasive visualization of the ductal system of major salivary glands. It is useful for diagnosing sialolithiasis and sialadenitis. Digital subtraction sialography, an invasive technique, had a substantial procedural failure rate, particularly for the submandibular duct. However, because of its higher spatial resolution, successfully completed digital subtraction sialography achieved superior diagnostic information compared with that of MR sialography.     

Functional evaluations of the parotid and submandibular glands using dynamic magnetic resonance sialography

PURPOSE: To evaluate the functional differences between the parotid and submandibular glands using dynamic MR sialography. METHODS: In 30 volunteers, the time-dependent changes (dynamic changes) in the maximum area of the detectable parotid and submandibular gland ducts on dynamic MR sialographic images were analysed. RESULTS: Dynamic changes in the parotid gland ducts were detectable on MR sialographic images in all volunteers, but images of the submandibular gland ducts were detectable in only 23 volunteers. In addition, the dynamic changes in the submandibular gland ducts in these 23 subjects were less than those seen in the parotid gland ducts. A relationship was found between the changing ratio of parotid (Pearson r=0.448, P=0.013) or submandibular gland ducts (Pearson r=0.418, P=0.047) and the salivary flow rate during the stimulation period. CONCLUSIONS: Dynamic MR sialography allows evaluation of rest and stimulated functioning and morphological evaluation of the parotid and submandibular glands. This technique appears to have many possible applications in the dental, medical and biological fields.     

3D MR sialography protocol for postradiotherapy follow-up of the salivary duct system

PURPOSE: To develop and evaluate an MR sialography protocol that reproducibly images the parotid and submandibular ducts over time, in 3D. Such a protocol is needed in order to investigate the possible radiation-induced changes to the salivary ducts in patients receiving radiotherapy to the head-and-neck. MATERIALS AND METHODS: MR sialography was performed on a 1.5-T MR scanner. Sequence parameters were optimized on 11 healthy volunteers. A 3D water-selective turbo spin echo (TSE) pulse sequence (TR/TE = 6000 msec/190 msec), using a two-element circular surface coil was applied twice in one MR session. In order to assess the reproducibility, the same procedure was repeated four to six months later. The quality of the MR sialograms was measured subjectively by developing a visibility scoring system and objectively by the means of contrast-to-noise ratio (CNR) of the ducts vs. fat (CNR(duct-fat)). RESULTS: High-quality, 3D MR sialographic images were obtained. The quality of the MR sialograms and the subjective visibility score of the salivary ducts were constant over time. The CNR(duct-fat) varied between volunteers (standard deviation, SD 26%) but it was relatively constant per volunteer (SD 5%). CONCLUSION: The MR sialography protocol presented in this study provides good quality 3D imaging of the major salivary ducts, submandibular duct, and the parotid duct and it can be used for the comparison of the salivary duct system of an individual over time.     

MR sialography of iatrogenic sialocele: comparison with conventional sialography

Objective

The objective of this study was to compare the conventional sialography with MR sialography in a series of patients with iatrogenic sialocele (sialocyst).

Methods

50 salivary glands in 39 patients with suspected inflammatory disease of the salivary gland underwent conventional sialography and MR sialography. Out of these 39 patients, 6 patients (age range: 16–35 years; 4 males and 2 females; mean age: 23.8 years) had sialoceles and formed our study group. MR sialography findings were compared with conventional sialography findings regarding demonstration of ductal anatomy, the cyst and its communication with the ductal system.

Results

MR sialography demonstrated the site of communication of the sialocyst with the ductal system in all six patients. MR provided additional information over conventional sialography in five cases. In four cases, the ductal system proximal to the cyst was not opacified on digital sialography but was well visualized in all cases by MR sialography. Constructive interference in steady-state (CISS) sequence demonstrated the intraglandular ducts and communication of cysts with ducts better than half-fourier acquisition single-shot turbo-spin echo (HASTE) images.

Conclusion

Our preliminary results suggest that MR sialography is a robust, non-invasive method for demonstrating the ductal system up to second-order branches, the site of ductal injury and the focal cystic lesion. MR provided at least the same information as conventional sialography in the evaluation of site of communication but provided additional information about the sialocyst and upstream ductal system in five cases. Being a non-invasive modality, we recommend MR sialography as the investigation of choice in the evaluation of an iatrogenic sialocyst.