3.0T磁共振DWI联合动态增强扫描在唾液腺肿瘤中的诊断价值

目的探讨3.0T磁共振扩散加权成像联合动态增强磁共振成像对唾液腺肿瘤的诊断价值。方法回顾性分析37例唾液腺肿瘤患者的临床和MRI资料,所有患者均经穿刺活检或手术病理证实,观察病灶形态、边界、包膜、T1WI及T2WI信号特征,并测量分析病变的ADC值和TIC曲线。结果唾液腺多形性腺瘤的ADC值(1.75±0.32×10~(-3)mm~2/s)、唾液腺腺淋巴瘤的ADC值(0.78±0.09×10~(-3)mm~2/s)和恶性肿瘤的ADC值(1.12±0.21×10~(-3)mm~2/s)三者之间均存在统计学差异,唾液腺良性肿瘤与恶性肿瘤的ADC值分别为(1.32±0.57×10~(-3)mm~2/s)和(1.12±0.21×10~(-3)mm~2/s),两者无明显差异,腺淋巴瘤与恶性肿瘤的ADC阈值为0.83×10~(-3)mm~2/s,多形性腺瘤和恶性肿瘤的ADC阈值为1.38×10~(-3)mm~2/s;37例唾液腺肿瘤中,11例表现A型曲线,15例表现为B型曲线,10例表现为C型曲线,淋巴管瘤表现为D型曲线,腺淋巴瘤的Tpeak值(22.7±11.7)s与恶性肿瘤的Tpeak值(43.2±14.1)s之间存在统计学差异(P0.01),腺淋巴瘤峰值时间早于恶性肿瘤;腺淋巴瘤廓清率(58.5%±7.4)高于恶性肿瘤廓清率(18.2%±12.1)(P0.01),根据TIC曲线类型,其诊断的敏感性、特异性、准确率、阳性预测值及阴性预测值分别为88.9%、80%、86.5%、92.3%、72.7%;对于B型和C型曲线采用ADC值进行修正诊断后,各值分别为92.5%、90%、91.9%、96.2%、81.8%。结论磁共振ADC值和TIC曲线有助于唾液腺肿瘤性病变的诊断,TIC曲线表现为B型或C型时,联合应用ADC值有利于提高唾液腺肿瘤的定性诊断。     

常规MRI联合最小ADC值鉴别腮腺混合瘤与腺淋巴瘤的价值

目的:探讨常规MRI联合最小ADC值鉴别诊断腮腺混合瘤与腺淋巴瘤的价值。方法:回顾性分析经病理组织学证实的腮腺混合瘤80例(84个病灶)及腺淋巴瘤50例(62个病灶)的MRI特点,并比较腮腺混合瘤和腺淋巴瘤的最小ADC值。结果:腮腺腺淋巴瘤的男性占比(100.0%,50/50)明显高于混合瘤(21.2%,17/80)(P0.05);腺淋巴瘤位于腮腺后下极占88.7%(55/62),明显高于混合瘤14.3%(12/84)(P0.05);腺淋巴瘤T_2WI呈低信号或低信号为主混杂信号占71.0%(44/62),明显高于混合瘤4.8%(4/84)(P0.05)。腮腺腺淋巴瘤最小ADC值明显低于混合瘤[(0.72±0.18)×10~(-3)mm~2/s vs.(1.30±0.26)×10~(-3)mm~2/s](P0.05)。结论:常规MRI联合最小ADC值有助于鉴别腮腺混合瘤与腺淋巴瘤。     

ADC值在常见脑转移瘤原发灶寻找中的价值

目的探讨MR扩散加权成像(DWI)及表观扩散系数(ADC)值在常见脑转移瘤原发灶寻找中的价值。方法回顾性分析105例经手术病理或临床及影像随诊证实的脑转移瘤患者,其中来源于肺癌53例,乳腺癌23例,消化道肿瘤29例。分别测量肿瘤实质区及瘤周水肿区ADC值,对不同来源脑转移瘤ADC值进行统计学分析,评价其是否具有临床价值。结果肺癌脑转移瘤,乳腺癌脑转移瘤和消化道肿瘤来源脑转移瘤实质区ADC值分别为(0.693±0.120)×10~(-3)mm~2/s,(0.857±0.088)×10~(-3)mm~2/s,(0.782±0.150)×10~(-3)mm~2/s,三组间ADC值差异具有统计学意义(F=15.321,P0.001),两组间比较差异均有统计学意义(P值均0.05);瘤周水肿区ADC值分别为:(1.630±0.158)×10~(-3)mm~2/s,(1.590±0.238)×10~(-3)mm~2/s,(1.601±0.181)×10~(-3)mm~2/s,差异无统计学意义(F=0.462,P=0.631)。结论常见脑转移瘤实质区ADC值与原发灶类型相关。因此,对于难以明确原发灶的脑转移瘤患者,可通过ADC值推测肿瘤来源,从而为临床治疗提供帮助。     

ADC值及eADC值在卵巢肿瘤定性诊断中的应用

目的 :探讨DWI中的ADC值及指数化表观扩散系数(eADC)值在卵巢肿瘤定性诊断中的应用价值。方法 :收集行MRI检查并经手术病理证实的65例卵巢癌患者,另选择卵巢良性肿瘤48例,比较2组的ADC值及eADC值。结果:65例卵巢癌的ADC值为(1.115±0.250)×10~(-3)mm~2/s,eADC值为(0.475±0.110) mm~2/s;48例卵巢良性肿瘤的ADC值为(1.673±0.310)×10~(-3)mm~2/s,eADC值为(0.271±0.150) mm~2/s。结论:卵巢癌与卵巢良性肿瘤的ADC值及eADC值差异有统计学意义,结合两者常规序列的MRI表现,可作出相对准确的诊断。     

最小ADC值在腮腺肿块良、恶性鉴别诊断中的价值

目的探讨最小表观扩散系数(ADC)值在鉴别诊断腮腺良、恶性肿块的价值。方法回顾性分析经手术病理证实的100例(148个病灶)腮腺良性肿块和35例(41个病灶)恶性肿瘤的MRI资料,测量并比较腮腺良、恶性肿块的最小ADC值。结果在DWI序列扫描中,腮腺良性和恶性肿块均呈高信号,恶性肿瘤最小ADC值为(1.08±0.27)×10~(-3)mm~2/s,低于混合瘤(1.38±0.29)×10~(-3)mm~2/s、高于良性淋巴源性肿块(0.72±0.28)×10~(-3)mm~2/s,两者间差异均有统计学意义(P0.01)。经ROC曲线分析,ADCmin阈值为1.17×10~(-3)mm~2/s时,区分腮腺恶性肿瘤和混合瘤的诊断灵敏度、特异度和曲线下面积分别为74.2%、75.6%和0.825;ADCmin阈值为0.94×10~(-3)mm~2/s时,区分腮腺恶性肿瘤和良性淋巴源性肿块诊断的敏感度、特异度和曲线下面积分别为85.4%、81.5%和0.959%。结论最小ADC值对腮腺良、恶性肿块具有鉴别诊断价值,ADCmin值在0.94×10~(-3)mm~2/s～1.17×10~(-3)mm~2/s区间对恶性肿瘤的诊断敏感度、特异度较高。     

原发性中枢神经系统淋巴瘤的DWI、^1H-MRS表现与病理对照分析

目的探讨原发性中枢神经系统淋巴瘤的DWI和^1H-MRS表现及其病理基础。方法对17例经病理证实的原发性中枢神经系统淋巴瘤的DWI、^1H-MRS与病理资料进行对照分析,比较瘤体与对侧正常脑白质ADC值以及瘤体与正常脑白质^1H-MRS代谢物峰高（Cho、Cr、NAA）和代谢物峰高比值（Cho/Cr、Cho/NAA）。结果原发性中枢神经系统淋巴瘤DWI图均表现为高信号。瘤体ADC值（6554±57．95）低于对侧正常脑白质ADC值（755±86．10）,差异有统计学意义（F=10．139,P〈O．05）。^1H-MRS：①病例组Cho（28．13±6．15）高于对照组（20．87士4．21）,差异有统计学意义（F=9．802,P〈O．05）;②病例组Cr（5．66±2．81）、NAA（8．31±3．26）分别低于对照组Cr（14．80±3．63）、NAA（24．88±7．41）,差异有统计学意义（F=47．645、56．783,P〈0．05）;③病例组Cho/Cr（5．82±2．12）、Cho/NAA（3．74±1．67）分别高于对照组Cho/Cr（1．44±0．25）、Cho/NAA（0．87±0．14）,差异有统计学意义（Z=-4．025、-4．025,P〈0．05）。所有病例均见有Lac和（或）Lip峰。免疫组化：17例均为B细胞型非霍奇金氏淋巴瘤肿瘤,瘤细胞LCA、CD20表达均阳性。结论DWI与^1H-MRS对原发性中枢神经系统淋巴瘤具有重要的诊断价值。     

磁共振扩散加权成像与氢质子波谱联合应用对脑内环形强化病变的鉴别诊断

目的:探讨磁共振扩散加权成像(DWI)与氢质子磁共振波谱(1 H-MRS)联合应用对常见脑内环形强化病变的鉴别诊断价值。方法:回顾性分析经手术病理证实或临床随访证实43例脑内环形强化病变的常规MRI图像、DWI信号特点、ADC值和多体素1 H-MRS波谱信息,比较DWI上信号特点、ADC值及1 H-MRS上AA峰、Cho峰、NAA峰、Cho/Cr、NAA/Cr、Cho/NAA的差别,并做统计学分析。结果:①DWI上12例脑脓肿(BA)患者9例(9/12)呈不同程度的高信号,ADC图呈低信号,1例(1/12)呈低信号,ADC图呈高信号,2例(2/12)呈混杂信号,平均ADC值为(0.521±0.183)×10-3 mm2/s;31例脑内囊性肿瘤(BCT)患者,28例(28/31)DWI上呈低信号,ADC图呈高信号,2例(2/31)呈混杂信号,1例(1/31)呈高信号,平均ADC值为(2.811±0.264)×10-3 mm2/s;BA与BCT的平均ADC值比较差异有统计学意义(P<0.01)。②1 H-MRS上12例BA内部出现特征性AA峰,脓肿壁Cho和NAA低于对侧,差异有统计学意义(P均<0.05),Cho/Cr、NAA/Cr、Cho/NAA差异无显著性意义(P均>0.05);31例BCT内均无AA峰,肿瘤壁Cho、Cho/Cr及Cho/NAA均较对侧正常组织明显升高,Cr及NAA较正常对照处明显减低,差异有显著性(P均<0.01)。结论:在常规MRI检查基础上,综合应用多体素1 H-MRS及DWI能对BA和BCT的鉴别诊断及判断肿瘤对肿瘤周围侵犯情况提供更多有价值的信息,是常规MRI检查序列的重要补充,能进一步提高MRI诊断准确率及临床指导作用。     

扩散加权成像和3D~1H-MRS对前列腺癌与前列腺炎的鉴别诊断价值

目的 探讨扩散加权成像(DWI)、三维氢质子磁共振波谱(3D~1H-MRS)对前列腺癌与前列腺炎的鉴别诊断价值.资料与方法 搜集经病理或实验室检查证实的前列腺炎患者33例,病理证实前列腺癌患者18例,正常健康自愿者12名,均行前列腺MRI、DWI检查,采用单次激发平面回波成像(echo planar imaging,EPI)序列,b值为0 s/mm~2和600 s/mm~2,并行3D~1H-MRS检查.结果 前列腺炎、前列腺癌和正常前列腺外周带的表观扩散系数(ADC)值分别为(1.60±0.17)×10~(-3)mm~2、(0.83±0.13)×10~(-3)mm~2、(2.14±0.13)×10~(-3)mm~2,组间差异有统计学意义(one-way ANOV,P<0.05),两两组间比较(LSD)各组间均有统计学意义.3D~1H-MRS代谢图中(胆碱+肌酸)/枸橼酸盐(Cho+Cre)/Cit分别为0.55±0.21、4.02±1.96、0.43±0.14,组间差异有统计学意义,两两组间比较,前列腺癌组和各组间差异均有统计学意义.结论 ADC值和3D~1H-MRS对前列腺癌与前列腺炎有重要的诊断和鉴别诊断价值.     

脑肿瘤应用磁共振弥散联合波谱分析技术临床诊断价值

目的探讨磁共振弥散加权成像(DWI)联合波谱分析技术应用于临床诊断脑肿瘤的价值。方法对140例患者临床诊治及影像学资料,比较不同脑肿瘤及其对侧正常脑组织的ADC值,记录不同肿瘤代谢物变化情况。结果脑膜瘤患者平均ADC值为(13.22±3.02)×10~(-4)mm~2/s,明显高于对侧正常脑组织ADC值(9.18±1.87)×10~(-4)mm~2/s,t=7.96,P=0.00;脑转移瘤患者平均ADC值为(12.11±2.86)×10~(-4)mm~2/s,明显高于其对侧正常脑组织ADC值(9.28±1.81)×10~(-4)mm~2/s,t=4.94,P=0.00;星形细胞瘤患者平均ADC值为(13.81±3.10)×10~(-4)mm~2/s,明显高于其对侧正常脑组织ADC值(9.46±1.79)×10~(-4)mm~2/s,t=9.09,P=0.00。脑转移瘤、脑膜瘤及星形细胞瘤患者NAA明显低于正常脑组织NAA水平,P0.05;星形细胞瘤患者NAA/Cho和NAA/Cr值明显高于脑转移瘤、脑膜瘤,P0.05;脑转移瘤、脑膜瘤及星形细胞瘤患者Cr水平明显低于正常脑组织Cr水平,P0.05。脑转移瘤患者中,7例Lac峰、18例Lip峰;脑膜瘤患者中,3例Lip峰、9例Lac峰、3例Ala峰;星形细胞瘤患者中,12例Lac峰、3例Lip峰。结论联合磁共振弥散加权成像与波谱分析技术可将脑肿瘤患者脑细胞结构变化描述的更加细致,更好的发现及辨别疾病,为临床疾病诊断和治疗方案制定提供参考依据。     

DWI和~1H-MRS在肝纤维化中的诊断价值

目的:探讨扩散加权成像(DWI)与氢质子波谱分析(1 H-MRS)在肝纤维化中的诊断价值。方法:使用腹腔注射CCl4溶液法诱导建立兔肝纤维化模型并进行DWI和1 H-MRS检查。DWI使用SE-EPI序列(b1=0s/mm2,b2=600s/mm2),1 H-MRS使用单体素点分辨波谱分析(PRESS)序列(TR 1500ms,TE 35ms),测量表观扩散系数(ADC)值及胆碱(Cho)和脂质(lipid)波峰下面积的比值(Cho/lipid)。以病理学肝纤维化分期为基础,将兔划分为无肝纤维化组(S0)、轻度-中度纤维化组(S1-S2)和重度纤维化及肝硬化组(S3-S4),比较不同组间ADC值和Cho/lipid变化规律。结果:随肝纤维化程度加重,ADC值依次降低(P<0.01),Cho/lipid依次升高(P<0.05);重度纤维化及肝硬化组与另两组ADC值及Cho/lipid差异均具有统计学意义(P均<0.05)。结论:DWI和1 H-MRS具备一定的定量肝纤维化及检测重度纤维化及肝硬化的能力。     

Salivary gland tumors at in vivo proton MR spectroscopy

PURPOSE: To prospectively evaluate whether proton magnetic resonance (MR) spectroscopy can be used to characterize salivary gland tumors (SGTs). MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Hydrogen 1 ((1)H) MR spectroscopy was performed with echo times of 136 and 272 msec at 1.5 T in both SGTs and normal parotid glands. Spectra were analyzed in the time domain by using prior knowledge in the fitting procedure to obtain peak amplitudes of choline (Cho), creatine (Cr), and unsuppressed water. Mean Cho/Cr and Cho/water ratios for each subgroup of SGTs were obtained, and results were compared by using a nonparametric t test. RESULTS: Successful spectra were acquired in 56 patients (35 men, 21 women; mean age, 56 years) with a total of nine malignant tumors and 47 benign SGTs (24 Warthin tumors, 22 pleomorphic adenomas, one oncocytoma). At an echo time of 136 msec, Cho/Cr ratios were obtained in 26 (47%) of 55 spectra, with a mean value (+/- standard deviation) of 1.73 +/- 0.47, 5.49 +/- 1.86, 3.46 +/- 0.84, and 2.45 for malignant tumors, Warthin tumors, pleomorphic adenomas, and oncocytoma, respectively. Differences were significant between Warthin tumors and pleomorphic adenomas (P = .028) and between benign SGTs and malignant tumors (P < .001). At an echo time of 272 msec, Cho/Cr ratios were obtained in 16 (30%) of 53 spectra, with a mean value of 2.27 +/- 0.69, 6.92 +/- 1.47, and 3.67 +/- 1.23 for malignant tumors, Warthin tumors, and pleomorphic adenomas, respectively. Differences were also significant between Warthin tumors and pleomorphic adenomas (P = .041) and benign SGTs and malignant tumors (P = .004). There was a significant difference in mean Cho/water ratio for Warthin tumors versus pleomorphic adenomas at echo times of 136 msec (P = .003) and 272 msec (P = .002) but not for benign SGTs versus malignant tumors. CONCLUSION: (1)H MR spectroscopy may be used to characterize SGTs, but a larger study is required to validate these initial results.     

The diagnostic efficacy of apparent diffusion coefficient value and Choline/Creatine ratio in differentiation between parotid gland tumors

Objective

To detect the diagnostic performance of apparent diffusion coefficient (ADC) value and Cho/Cr ratio in distinguishing various pathological subtypes of parotid gland tumors.

3.0T MR动脉自旋标记对腮腺肿瘤的鉴别诊断价值

目的:初步探讨3.0T磁共振动脉自旋标记技术(ASL)对腮腺肿瘤的鉴别诊断价值。方法:前瞻性搜集2017年3月-2020年1月因腮腺肿物于本院就诊及治疗的患者作为研究对象,所有研究对象均行常规MR平扫及ASL扫描,测量ASL序列图像上肿瘤组织的肿瘤血流量(TBF),并将计算出的标准化肿瘤血流量(nTBF)与病理结果进行对比分析。结果:本研究总共纳入45例经术后病理证实的腮腺肿瘤患者。其中良性肿瘤28例,包括腺淋巴瘤14例,多形性腺瘤14例;恶性肿瘤共17例。测量并经计算得出腺淋巴瘤、多形性腺瘤、恶性腮腺肿瘤的nTBF分别为:3.71±1.65、0.89±0.25、1.55±0.60。腺淋巴瘤的nTBF明显高于多形性腺瘤(P<0.01)和恶性肿瘤(P<0.01),但是多形性腺瘤和恶性肿瘤的nTBF差异无统计学意义(P=0.073)。ASL能将腮腺腺淋巴瘤从多形性腺瘤及恶性肿瘤中鉴别出来,但是无法鉴别多形性腺瘤与恶性肿瘤。ASL诊断腮腺腺淋巴瘤的ROC曲线下面积为0.935,nTBF的诊断阈值为2.03,诊断腺淋巴瘤的敏感度和特异度分别为92.9%、93.5%。结论:3.0T MR ASL技术可以无创地、定量地评价腮腺肿瘤的TBF,并对腺淋巴瘤的诊断和鉴别诊断具有较高的价值。     

Advanced magnetic resonance imaging findings in salivary gland tumors

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.     

Salivary gland tumors: evaluation with two-phase helical CT

PURPOSE: To evaluate two-phase helical computed tomography (CT) in the characterization of salivary gland tumors. MATERIALS AND METHODS: Sixty-four patients with major salivary gland tumors underwent two-phase helical CT. The histopathologic diagnosis was obtained by means of surgical resection or biopsy in all patients. After the injection of 90 mL of contrast material at a rate of 3 mL/sec, helical CT scans were obtained at early and delayed phases with scanning delays of 30 and 120 seconds, respectively. The attenuation change and enhancement patterns in the tumors were assessed. The attenuation change in the tumor also was assessed quantitatively as the ratio of the CT number (in Hounsfield units) at delayed phase scanning to that at early phase scanning. RESULTS: There were 35 pleomorphic adenomas, nine Warthin tumors, and 20 malignant tumors. Two-phase helical CT showed increase in attenuation in 30 (86%) pleomorphic adenomas, decrease in eight (89%) Warthin tumors, and increase in 11 (55%) and no change in eight (40%) malignant tumors at delayed phase scanning. A multinodular enhancement pattern was found in only 12 (34%) pleomorphic adenomas. The ratio of CT numbers was significantly different between Warthin tumors and pleomorphic adenomas and between Warthin tumors and malignant tumors. CONCLUSION: The analysis of enhancement patterns by using two-phase helical CT will be helpful in the differential diagnosis of salivary gland tumors.     

The role of proton MR spectroscopy and apparent diffusion coefficient values in the diagnosis of malignant thyroid nodules: preliminary results

PurposePerformance of proton magnetic resonance spectroscopy (H-MRS) and apparent diffusion coefficient (ADC) values in the diagnosis of malignant thyroid nodules.MethodIn a retrospective study with malignant nodules of 14 patients, H-MRS and diffusion-weighted MR imaging (DWI) were performed. Choline (Cho) peak, Cho/creatine (Cr) ratio, and ADC values of malignant nodules were correlated with the five benign nodules and four normal-appearing thyroid lobe parenchymata. The gold standard reference was fine needle aspiration biopsy and histopathology.ResultsAt echo time 40–144-ms acquisitions, average Cho/Cr ratio for the malignant nodules was 2.95±1.54–5.30±2.38, cutoff values were >0.805 and >1.225, and ADC values were 0.06±0.02.ConclusionH-MRS acquisitions, DWI, and ADC mapping give diagnostic data about the nature of the nodules.     

Value of apparent diffusion coefficient calculation in the differential diagnosis of parotid gland tumors

Background: The differential diagnosis of parotid gland tumors is often difficult with conventional magnetic resonance imaging.

Purpose: To determine whether the calculation of the apparent diffusion coefficient (ADC) is valuable for making the differential diagnosis of parotid tumors.

Material and Methods: Thirty parotid masses in 28 patients and 24 healthy parotid glands in 12 controls were examined in this prospective study. Diffusion-weighted magnetic resonance imaging with echo-planar spin-echo sequences was used to evaluate each subject. The ADC of each tumor and each healthy parotid gland was calculated. Tumor diagnoses were confirmed by the results of histopathologic analysis.

Results: The following types of masses were identified: 11 Warthin tumors, nine pleomorphic adenomas, seven malignant tumors, one basal cell adenoma, and two benign cysts. The mean ADC value for the Warthin tumors was 0.97±0.16×10^-3 mm²/s, for the pleomorphic adenomas was 1.74±0.37×10^-3 mm²/s, for the malignant tumors was 1.04±0.35×10^-3 mm²/s, and for the normal parotid glands was 0.34±0.20×10^-3 mm²/s. The respective ADC value for the single basal cell adenoma was 1.40×10^-3 mm²/s. Statistically significant differences were identified between the subjects with pleomorphic adenoma and those with another type of parotid tumor, and between subjects with healthy parotid glands and those with a tumor.

Conclusion: Calculating the ADC appears to be useful in differentiating pleomorphic adenomas from other types of parotid gland tumors.     

常规MRI联合DWI在腮腺常见肿瘤中的诊断价值

目的:探讨常规MRI联合DWI对腮腺常见肿瘤的诊断价值。方法:回顾性分析经病理证实的62例腮腺肿瘤的MRI图像,根据其DWI图行ADC图重建,测量肿瘤的ADC值。按发病率将62例病例分成3组:多形性腺瘤、腺淋巴瘤、恶性肿瘤。多形性腺瘤31例,全部单发;腺淋巴瘤19例,9例单发,10例多发,共30个病灶;恶性肿瘤12例,3例淋巴瘤多发,其余均为单发,共18个病灶。比较分析3种肿瘤的ADC值。结果:多形性腺瘤和腺淋巴瘤多发生于腮腺浅叶(43个,70.5%),肿瘤边界多清楚,体积一般较恶性肿瘤小;恶性肿瘤位于深叶者8个(44.4%),边界清楚或不清楚,多伴有颈部淋巴结肿大(10例,83.3%)。多形性腺瘤及恶性肿瘤平均ADC值均高于腺淋巴瘤(P=0.000、0.002),且多形性腺瘤平均ADC值高于恶性肿瘤(P=0.001)。结论:腮腺肿瘤的常规MRI征象具有一定特点,联合DWI能为腮腺常见肿瘤的诊断及鉴别诊断提供更多依据。     

颞叶癫痫~1H-MRS和DWI的变化及其相关性研究

目的 探讨~1H-MRS和DWI在反映海马硬化病理结构改变中的价值.方法 采用3.0T磁共振扫描仪对12例伴有单侧海马硬化的发作间期颞叶癫痫(TLE)患者及12例正常对照者行单体素~1H-MRS及DWI检查.比较海马N-乙酰天门冬氨酸/肌酸+胆碱[NAA/(Cr+Cho)]值,表观弥散系数(ADC)值在患侧、对侧和对照组之间的差异,分析NAA/(Cr+Cho)和ADC值之间的相关性.结果 TLE患者患侧海马NAA/(Cr+Cho)值低于对侧海马及对照组;发作间期海马ADC值高于对侧海马及对照组;患侧海马NAA/(Cr+Cho)和ADC值之间存在相关性(r=-0.79,P=0.002).结论 TLE患者患侧发作间期海马NAA/(Cr+Cho)值降低,ADC值升高,两者之间呈显著的负相关;~1H-MRS联合DWI可在活体无创反映海马硬化的病理结构改变.