磁共振弥散加权成像在糖尿病肾病中的应用

目的探讨磁共振扩散加权成像(DWI)测量糖尿病(DM)肾病(DN)患者肾脏的表观扩散系数(ADC)值对DN的诊断价值。方法选择2010年10月1日至2012年3月1日于该院内分泌科治疗并具有明确诊断及临床分期的68例2型糖尿病(T2DM)患者,依据实验目的分为DM组和DN组,后者又分为DNⅢ期组和DNⅣ期组,其中DM组22例,DN组46例(DNⅢ期组24例,DNⅣ期组22例),所有患者均进行双侧肾脏冠状位磁共振扩散加权成像(DWI)扫描,弥散梯度因子(b值)为(0,600 s/mm2)和(0,1 000 s/mm2)。对DM组及DN组患者肾脏表面弥散系数(ADC)值进行ANOVA分析,明确是否存在差异。结果 b值为600 s/mm2时,DNⅣ期组肾脏ADC值与DM组比较,有统计学差异(P<0.05);DNⅢ期组肾脏ADC值分别与DM组、DNⅣ期组比较没有统计学差异(P>0.05)。b值为1 000 s/mm2时,DNⅢ期组肾脏ADC值与DM组比较有统计学差异(P<0.05);DNⅣ期组肾脏ADC值与DM组比较差异显著(P<0.01);DNⅢ期组肾脏ADC值与DNⅣ期组比较无统计学差异(P>0.05)。结论选用高b值DMI能发现早期DN的肾功能损害,所测量的ADC值与DN的严重程度呈负相关。     

磁共振弥散加权成像在恶性肿瘤疗效评价方面的应用

恶性肿瘤的发病率呈逐年上升趋势,对人类生存构成严重威胁.所以,早诊早治已成为提高恶性肿瘤预后的关键.大多数恶性肿瘤的治疗方法除手术外,主要为放疗和(或)化疗.目前,临床评价疗效的传统方法是监测实验室指标和CT(或MRI)的肿瘤形态学观察.这些方法通常在治疗数月后出现变化从而反映疗效,时间较长.为了能够尽早评价疗效,及早指导下一步治疗,核磁共振弥散加权成像(DWI)近年来成为研究热点.下面将对其在恶性肿瘤疗效评价中的应用作一综述.     

磁共振弥散加权成像在宫颈癌放化疗疗效早期评估中的应用价值

目的 探讨磁共振弥散加权成像(DWI)在治疗早期预测宫颈癌放化疗疗效的应用价值.方法 纳入经宫颈活检病理证实的宫颈癌患者88例,分为完全缓解(CR)组(70例)和部分缓解(PR)组(18例).患者均接受根治性同步放化疗,分别在放化疗前、腔内近距离放疗前及放化疗结束后1个月进行磁共振成像(MRI)检查和DWI检查,测量3...     

磁共振弥散加权成像结合常规序列在食管癌显示及术前分期中的应用

目的探讨磁共振弥散加权成像(DWI)结合常规序列对食管癌诊断及其在术前T分期中的临床应用价值。方法对30例被消化道内镜确诊为食管癌患者做常规MRI序列和DWI横断面扫描,b=500、800、1 000 s/mm2,然后分别计算其表观弥散系数值。在DWI结合常规序列图像上测量病变的长度,并与食管钡餐检查、CT、常规T2WI及手术切除病理大体标本的病变长度进行比较。结果所有食管癌病灶在MR-DWI上都是表现为高信号,且明显高于正常食管壁。随着b值增大,病灶的ADC值是逐渐减小的。MR-DWI结合常规序列显示的病变长度与病理结果显示的长度无统计学差异(P=0.955)且有着较高的相关性,与病理大体标本显示病变长度间的相关系数达到0.999,优于食管钡餐检查(r=0.858)、CT(r=0.971)和常规T2WI(r=0.985)。MR-DWI结合常规序列对于食管癌术前T3和T4期诊断准确率分别为85.71%和86.67%,优于常规MRI序列和CT检查,而对T1~2期诊断准确率仅为33.33%。结论 DWI结合常规序列在食管癌的诊断及T分期中具有一定的临床价值,可以为临床提供更多的影像学信息。     

磁共振全身弥散加权成像在骨转移瘤诊断中的应用价值

目的探讨磁共振(MRI)全身弥散加权成像(WB-DWI)在骨转移瘤早期诊断中的应用价值。方法对经病理检查证实的41例恶性肿瘤患者行WB-DWI检查,对可疑病变部位行常规MRI或CT检查,将WB-DWI与常规MRI/CT检查结果进行比较,再结合活检病理检查、诊断性治疗及随访观察结果,评价WB-DWI显示骨转移瘤的准确性。结果 WB-DWI共诊断67处骨转移瘤,漏诊6处,其中颅骨2处、肩胛骨1处、胸骨1处、腰骶椎成骨型转移2处;误诊2处,均为椎体血管瘤;发现2例肋骨转移,常规CT和MRI漏诊。常规MRI/CT共诊断69处骨转移瘤,其中63处病灶与WB-DWI所见吻合。结论 WB-DWI在骨转移瘤早期诊断中具有较大的应用价值。     

磁共振弥散加权成像对急性胰腺炎严重性分级的诊断价值

目的 探讨磁共振弥散加权成像（DWI）及表观弥散系数（ADC）值对急性胰腺炎（AP）严重性分级的诊断价值.方法 收集57例AP及13例正常胰腺含有DWI的磁共振成像（MRI）资料.参照Balthazar CT分级标准,将AP的MRI表现分为相应的A、B、C、D、E5级,测量炎症胰腺及正常胰腺的ADC值.应用单因素方差分析（ANOVA）对各级别AP之间、各级别与正常胰腺之间的ADC值进行统计学分析.结果 57例AP的MRI分为A级6例,B级9例,C级11例,D级10例,E级21例.炎症胰腺在DWI图像均呈高信号（100％）.A、B、C、D、E级AP的平均ADC值分别为（1.138 ±0.024）、（1.289±0.179）、（1.513 ±0.156）、（1.554 ±0.248）、（1.938±0.567） ×10-3 mm2/s,正常胰腺的ADC值为（1.687±0.129）×10-3mm2/s.A、B级AP的ADC值显著低于E级（P值均＜0.01）及正常胰腺（P值均＜0.05）,C级的ADC值低于E级（P＜0.05）,其余各级别之间,C、D、E级与正常胰腺之间的ADC值差异均无统计学意义（P值均＞0.05）.结论 磁共振DWI有利于Balthazar分级中形态变化不明显的A级及B级AP的早期诊断,但ADC值对AP严重性的分级诊断无明显价值.     

3.0T磁共振弥散加权成像对肝硬化的诊断价值初步研究

目的 初步探讨磁共振弥散加权成像ADC值对肝硬化的诊断价值.方法 采用3.0T全身磁共振扫描系统对23例肝硬化患者、15例健康志愿者(对照组)行轴位弥散加权成像扫描,b值选用0、500、800、1000s/mm2,分别在肝脏右前叶、右后叶、左内叶测量各组的ADC值,进行统计学分析.结果 两组中肝脏左叶ADC值大于肝脏右叶的ADC值,且具有显著性差异;Z=-4.621 P=0.0001;右前叶ADC值略大于右后叶ADC值,两者之间未见显著性差异,Z=-1.552 P=0.06.b＝500、800、1000s/mm2时肝硬化组肝脏的ADC值均低于对照组肝脏的ADC值,且与对照组肝脏ADC值之间均有显著性差别.结论 3.0T磁共振弥散加权成像ADC值在诊断肝硬化引起弥漫肝实质损害中具有很大的临床价值.     

多b值弥散加权磁共振成像在老年原发性中枢神经系统淋巴瘤患者预后评估中的应用价值

目的 探讨多b值弥散加权磁共振成像(multi-b-value diffusion-weighted magnetic resonance imaging,eDWI-MRI)参数及临床特征在老年原发性中枢神经系统淋巴瘤(primary central nervous system lymphoma,PCNSL)患者预后...     

磁共振弥散加权成像对肾癌与肾血管平滑肌脂肪瘤的诊断价值

目的探讨磁共振弥散加权成像对肾癌和肾血管平滑肌脂肪瘤的诊断价值。方法选取85例肾肿瘤患者（包括肾癌54例,肾血管平滑肌脂肪瘤31例）,术前行常规MRI平扫检查及弥散加权成像,并在取b值为800 s/mm2时直接测量肾脏肿瘤实性部分的平均表观弥散系数（ADC）值。结果 54例肾癌肿瘤实性部分在弥散加权成像上表现为高信号;31例肾血管平滑肌脂肪瘤表现为边界清楚的混杂信号,其中软组织部分呈等、稍高信号,脂肪部分呈低信号。在b值取800 s/mm2时,肾癌、血管平滑肌脂肪瘤的ADC值比较差异具有统计学意义（P〈0.05）。结论通过弥散加权成像及ADC值,可以更多了解肿瘤的内部结构,有助于肾脏良恶性肿瘤的诊断和鉴别诊断。     

灌注和弥散加权磁共振成像在超早期脑梗死中的应用

灌注和弥散加权磁共振成像在脑梗死超早期有着潜在的应用价值。近年来的研究认为，利用灌注和弥散成像不一致区代表缺血半暗带过于简化，而超早期MR灌注参数的改变结合弥散成像可更准确地判断缺血半暗带，对超早期指导溶栓治疗和预评价临床预后有重要意义。     

Testicular tumors: discriminative value of conventional MRI and diffusion weighted imaging

To explore the feasibility of using conventional MRI features combined with apparent diffusion coefficient (ADC) values for the differential diagnosis of testicular tumors.A total of 63 patients with pathologically confirmed testicular tumors were enrolled in this study. In particular, there were 46 cases of malignant lesions and 17 cases of benign lesions. All patients underwent conventional magnetic resonance imaging (MRI) and diffusion weighted imaging. Multivariate logistic regression models and receiver operating characteristic curves were constructed to assess diagnostic accuracies.T2-homogeneity, intratumoral septa, and peritumoral infiltration were more common in the malignant group, and capsule sign was more common in the benign group (P < .05 for all). The mean ADC value of the malignant group was lower than that of the benign group (P < .05). When the ADC value ≤ 0.90 × 10⁻³ mm²/s, the diagnosis tended to be malignancy. The conventional MRI model could achieve better diagnostic accuracy than ADC values alone (P < .05). Compared with the conventional MRI model, the specificity and accuracy of the full model (ADC and conventional MRI model) increased by 9.8% and 3.2%, respectively. T2-homogeneity and T2-hypointensity were more common in seminoma and lymphoma, cystic changes were more common in nonseminomatous germ cell tumor (NSGCT), and intratumoral septa was more common in seminoma (P < .05 for all). The ADC value of NSGCT was larger than seminoma, and lymphoma was the smallest (P < .05 for all). Cystic changes, T2-hypointensity, intratumoral septa, and ADC value were independent factors for differentiating the seminoma, NSGCT, and lymphoma subgroups.A combination of conventional MRI features and ADC values can improve the diagnostic efficiency for differentiating benign and malignant testicular tumors, and can additionally distinguish different subtypes of malignant testicular tumors.     

磁共振扩散加权成像评价肝硬化的应用价值

目的探讨肝硬化磁共振扩散加权成像（DW I）表观弥散系数（ADC）值变化与肝硬化程度之间的相关性。方法对54例肝硬化患者及48例正常肝脏行扩散加权成像,并测量ADC值,DW I序列所选用弥散敏感度（b值）分别为（0,400,600,800）s/mm2。在b1和b2（ADC1）、b1和b3（ADC2）及b1和b4（ADC3）计算肝脏ADC值。结果肝硬化平均ADC1、ADC2、ADC3均显著低于正常肝脏（P〈0.05）;Ch ild A、B、C各级肝硬化与正常肝脏相比,ADC值均明显降低（P〈0.05）;ADC值随肝硬化程度的加重而降低（P〈0.05）;各组ADC值随b值增大而降低（P〈0.05）;b值为600 s/mm2、800 s/mm2时,认为（1.30×10-3）s/mm2可能为正常肝脏与肝硬化的分界点,低于此值即可考虑为肝硬化。结论DW I-ADC值的测定可辅助临床诊断早期肝硬化并反映肝硬化的动态变化,是评价肝硬化的有价值的参考指标。     

Importance of b value in diffusion weighted imaging for the diagnosis of pancreatic cancer

AIM:To investigate the use of multi-b-value diffusionweighted imaging in diagnosing pancreatic cancer.METHODS:We retrospectively analyzed 33 cases of pancreatic cancer and 12 cases of benign pancreatic tumors at the Second Affiliated Hospital of Kunming Medical University from December 2008 to January2011.The demographic characteristics,clinical presentation,routine magnetic resonance imaging and diffusion weighted imaging(DWI)features with different b values were reviewed.Continuous data were expressed as mean±SD.Comparisons between pancreatic cancer and benign pancreatic tumors were performed using the Student’s t test.A probability of P<0.05 was considered statistically significant.RESULTS:Thirty-three patients with pancreatic cancer were identified.The mean age at diagnosis was 60±5.6 years.The male:female ratio was 21:12.Twenty cases were confirmed by surgical resection and 13 by biopsy of metastases.T1 weighted images demonstrated a pancreatic head mass in 16 patients,a pancreatic body mass in 10 cases,and a pancreatic tail mass with pancreatic atrophy in 7 cases.Eight patients had hepatic metastases,13 had invasion or envelopment of mesenteric vessels,4 had bone metastases,and 8had lymph node metastases.DWI demonstrated an irregular intense mass with unclear margins.Necrotic tissue demonstrated an uneven low signal.A b of 1100s/mm2was associated with a high intensity signal with poor anatomical delineation.A b of 700 s/mm2was associated with apparent diffusion coefficients(ADCs)that were useful in distinguishing benign and malignant pancreatic tumors(P<0.05).b values of 50,350,400,450 and 1100 s/mm2were associated with ADCs that did not differentiate the two tumors.CONCLUSION:Low b value images demonstrated superior anatomical details when compared to high b value images.Tumor tissue definition was high and contrast with the surrounding tissues was good.DWI was useful in diagnosing pancreatic cancer.     

磁共振扩散成像在诊断肝脏占位病变中的应用

量化分析肝脏占位性病变的磁共振扩散成像(DWI)的表面扩散系数(ADC值)的变化规律。对69个常见肝脏占位性病变病灶(肝血管瘤、肝囊肿、原发性肝癌、肝转移瘤)行磁共振扩散成像检查,计算病灶的ADC值。四种常见肝脏占位性病变病灶的ADC均值,肝血管瘤：(2．38±0．56)×10~(-3)mm~2/s肝囊肿：(2．47±0．71)×10~(-3)mm~2/s原发性肝癌：(1．23±0．14)×10~(-3)mm~2/s肝转移瘤：(1．44±0．46)×10~(-3)mm~2/s。综合量化分析病灶的ADC值的变化,能更准确的判断肝脏占位性病变的性质,为肝脏占位性病变的诊断及鉴别诊断提供更准确的结论。     

3.0T磁共振扩散加权成像在乳腺癌诊断及病理分型中的应用价值

目的探讨3.0T磁共振扩散加权成像（DWI）在乳腺癌诊断中的应用价值,并分析表观弥散系数（ADC）对乳腺癌病理分型的意义。 方法回顾性分析2017年9月至2018年9月牡丹江医学院附属红旗医院收治的经手术或穿刺活检病理证实的72例乳腺癌患者。比较MR平扫、DWI及两者联合诊断乳腺癌的准确性;比较b值为1000 s/mm²时不同病理类型乳腺癌ADC值的差异。 结果本组72例乳腺癌患者,病理证实非浸润性癌19例（导管内原位癌17例,小叶原位癌2例）;浸润性癌53例（浸润性导管癌42例,浸润性小叶癌11例）。MR平扫、DWI及两者联合诊断本组72例乳腺癌患者的准确率分别为88.9%（64/72）、65.3%（47/72）、95.8%（69/72）。b值为1000 s/mm²时,导管内原位癌与浸润性导管癌、小叶原位癌与浸润性小叶癌平均ADC值差异均有统计学意义（t=0.015,P<0.001;t=3.095,P<0.05）。 结论DWI对乳腺癌的诊断有一定的临床价值,MR平扫与DWI两者联合对乳腺癌诊断具有较高的准确性。ADC值对乳腺浸润性癌与非浸润性癌的区分有价值。     

Differentiation between pancreatic carcinoma and mass-forming chronic pancreatitis: usefulness of high b value diffusion-weighted imaging

OBJECTIVE: To investigate the value of high b value diffusion‐weighted (DW) imaging in differentiating between pancreatic carcinoma and mass‐forming chronic pancreatitis (MFCP). METHODS: Fifty‐one consecutive patients with pathology‐proven pancreatic carcinoma (n = 37) or MFCP (n = 14) were evaluated with DW imaging (b value, 0 and 1000 s/mm²) at a 3‐T MR system. Overall 20 healthy volunteers were evaluated as the control group. The apparent diffusion coefficient (ADC) values of normal pancreas, pancreatic carcinoma, MFCP, and mass‐associated obstructive pancreatitis were measured. RESULTS: On high b value (1000 s/mm²) DW images, both pancreatic carcinoma and MFCP were hyperintense focal lesions; mass‐associated obstructive pancreatitis occurred in 17 of 37 (45.9%) pancreatic carcinoma and 8 of 14 (57.1%) MFCP. The ADC (×10^?3 mm²/s) of the pancreatic carcinomas (1.06 ± 0.15) was significantly lower than that of normal pancreas (1.47 ± 0.18; P < 0.01), MFCP (1.35 ± 0.14; P < 0.01) and mass‐associated chronic pancreatitis (1.44 ± 0.17; P < 0.01). The ADC of MFCP was also lower than that in the normal pancreas (P = 0.025), whereas the ADC of mass‐associated obstructive pancreatitis was not different from those of the MFCP (P = 0.113) and normal pancreas (P = 0.544). When 1.195 was used as the optimal cut‐off value, ADC quantification obtained a sensitivity of 85.7% and a specificity of 86.5% for differentiating pancreatic carcinomas from MFCP. CONCLUSION: High b value DW imaging in combination with ADC quantification at a 3‐T MR system is useful in differentiating between pancreatic carcinoma and MFCP.     

磁共振扩散加权成像对肝癌的诊断及鉴别诊断作用

目的:探讨磁共振扩散加权成像对肝癌诊断及鉴别诊断的作用.方法:选取肝脏占位性病变88例,其中原发性肝细胞癌28例,转移瘤15例,肝血管瘤33例,肝囊肿12例.应用不同的b值分别行轴位扩散加权成像扫描,在拟合出的ADC图上分别测出ADC值并进行统计分析.结果:随着b值或b值差的增大,肝脏占位病变的ADC值明显减小,而且波动范围减小,b值越大时越接近实际DC值.采用b值差为500时各组病变的ADC值作为肝脏占位病变的ADC平均值.肝囊肿(3.24±0.68)ADC值明显高于原发性肝癌(1.20±0.32)、血管瘤(2.01±0.53)和转移瘤(1.57±0.42)(P<0.01).血管瘤ADC值显著高于原发性肝癌(P<0.01)及转移瘤(P<0.05).转移瘤ADC值高于原发性肝癌,但无统计学意义(P>0.05).结论:ADC值的应用可大大提高MRI对肝癌的诊断和鉴别诊断能力.     

兔急性脑缺血再灌注扩散加权成像的实验研究

目的 探讨兔脑大脑中动脉缺血再灌注（MCAOI/R）后磁共振扩散加权成像（DWI）的特点.方法 将制作成功的兔MCAOI/R模型58只,随机分为永久性缺血组30只（再分为缺血1、3、6、12、24、48 h组,每组5只）和缺血再灌注组28只（再分为缺血再灌注0、2、5、11、23、47 h组,每组分别为5、5、4、5、4只）;另取10只动物行假手术分别作为缺血组（5只）及再灌注组（5只）的对照组;观察不同时间DWI像上高信号区范围变化及表观扩散系数（ADC）的演变特点.结果 各组于缺血1 h均见到DWI像上明显的高信号,并伴ADC值的下降.缺血组不同缺血时间点各组平均ADC值呈先下降后上升的趋势.与缺血1 h比,各缺血时间点DWI像上的高信号区范围均有不同程度的增大,24 h后趋于稳定.再灌注组与再灌注前（缺血1 h）相比,再灌注2、5 h组均表现为DWI像上高信号区范围的缩小及ADC值升高;再灌注11h组表现为高信号范围的增大并ADC值升高;再灌注23、47 h组表现为高信号范围的增大而ADC值出现较明显的下降.结论 急性脑缺血后DWI像高信号区及ADC值的下降经早期再灌注后可明显改善,但持续的再灌注可能导致ADC值的再次下降.