3.0T MR灌注加权成像和扩散加权成像在胰腺肿块诊断中的应用

目的 评价3.0 T MR灌注参数和ADC值在胰腺癌和胰腺肿块诊断中的应用价值.方法 选取20名正常志愿者及25例经手术病理证实的胰腺癌患者,行基于T1对比胰腺灌注扫描.测量胰腺癌组织、邻近胰腺组织、远端炎症区及正常胰腺组织的血管通透性常数(Ktrans)、血液回流常数(Kep)及细胞外血管外间质容量(Ve),并采用方差分析进行比较.15名正常志愿者及58例患者(胰腺癌30例、肿块型胰腺炎9例、实性假乳头状瘤9例及神经内分泌肿瘤10例)行DWI,采用方差分析比较不同组织的ADC值,并应用ROC曲线分析其诊断效能.结果 胰腺癌组织、邻近胰腺组织、远端炎症区及正常胰腺的Ktrans分别为(1.66±1.25)、(3.77±2.67)、(1.16±0.94)和(2.69±1.46)/min,差异有统计学意义(F=8.160,P＜0.01),其中胰腺癌组织的Ktrans低于正常胰腺组织(P=0.011)及邻近胰腺组织(P=0.002);上述部位的Kep分别为(2.53±1.55)、(5.64±2.64)、(1.70±0.91)和(4.28±1.64)/min,差异有统计学意义(F=4.544,P＜0.01),其中胰腺癌组织的Kep值均低于正常胰腺组织(P=0.035)及邻近胰腺组织(P=0.041);Ve中位数分别为0.926、0.839、0.798和0.659,差异有统计学意义(χ2=12.040,P＜0.01),胰腺癌的Ve值高于正常胰腺(P＝0.002).胰腺癌组织、肿块型胰腺炎、实性假乳头状瘤、神经内分泌肿瘤及正常胰腺的ADC值分别为(1.57±0.26)×10-3、(1.19±0.15)×10-3、(1.05±0.35)×10-3、(1.62±0.41)×10-3及(1.82±0.25)×10-3 mm2/s,差异有统计学意义(F=21.681,P＜0.01),其中肿块型胰腺炎、胰腺癌及正常胰腺的ADC值两两之间差异均有统计学意义(P＜0.01),实性假乳头状瘤的ADC值低于神经内分泌肿瘤(P＜0.01).以ADC≥1.33×10-3mm2/s从肿块型胰腺炎中鉴别诊断胰腺癌,灵敏度和特异度分别为86.7%和88.9%,阳性预测值为96.3%,阴性预测值为66.7%.以ADC值≤1.25×10-3 mm2/s作为诊断实性假乳头状瘤的临界点,灵敏度和特异度分别为77.8%和100.0%,阳性预测值100.0%,阴性预测值83.3%.结论 3.0 T MR PWI显示胰腺癌的Ktrans和Kep较低,而Ve较高;呼吸门控DWI序列的ADC值能够较好地反映正常胰腺及胰腺肿块的组织病理生理特征,有助于胰腺肿块的诊断与鉴别.

Abstract：

Objective To investigate the value of MR perfusion parameters and ADC in the diagnosis of pancreatic cancer and pancreatic mass at 3.0 T MR. Methods Twenty healthy volunteers and 25 patients with pancreatic cancers proven by pathological results underwent MR PWI at a 3.0 T scanner. A two-compartment model was used to quantify Ktrans, Kep and Ve in the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue. All parameters among different tissues were analyzed and compared with ANONA. Fifteen normal volunteers and 58 patients, including 30 patients with pancreatic cancer (proven histopathologically), 9 patients with pancreatitis pseudotumor (4 patients proven by histopathological results, 5 patients proven by follow-up after treatment), 9 patients with solid pseudopapillary tumor of pancreas (SPTP, proven histopathologically) and 10 patients with pancreatic neuroendocrine tumor (PET, proven by histopathology), underwent respiratory-triggered DWI on 3.0 T. ADC values of normal pancreas and all types of pancreatic lesions were statistically analyzed and compared with ANONA. ROC curve was used to analyze the diagnostic power of ADC value. Results Ktrans of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (1.66±1.25), (3.77±2.67),(1.16±0.94) and (2.69±1.46)/min respectively(F=8.160, P＜0.01). LSD test showed that Ktrans in the pancreatic cancer was statistically lower than that in normal pancreas (P=0.011)and adjacent pancreatic tissue(P=0.002). Kep of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (2.53±1.55), (5.64±2.64), (1.70±0.91) and (4.28±1.64)/min respectively(F=4.544, P＜0.01). LSD test revealed that Kep in pancreatic cancer was statistically lower than that in normal pancreatic tissue (P=0.035)and adjacent pancreatic tissue(P=0.041). The median of Ve among the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were 0.926, 0.839, 0.798 and 0.659 respectively (χ2=12.040,P＜0.01). Ve in pancreatic cancer was statistically higher than that in normal pancreatic tissue (P=0.002). ADC values of the pancreatic cancer, pancreatitis pseudotumor, SPTP, PET and normal pancreas were(1.57±0.26)×10-3,(1.19±0.15)×10-3,(1.05±0.35)×10-3,(1.62±0.41)×10-3 and (1.82±0.25)×10-3 mm2/s(F=21.681, P＜0.01). LSD test showed there were significant statistical differences in ADC values among pancreatic cancer, pancreatitis pseudotumor and normal pancreatic tissue (P＜0.01). ROC curve disclosed that the sensitivity, specificity, positive predictive value and negative predictive value were 86.7%, 88.9%, 96.3% and 66.7% respectively, when ADC≥1.33×10-3 mm2/s was used as a cutoff value for differential diagnosis of PDCA from MLP. The sensitivity, specificity, positive predictive value and negative predictive value were 77.8%, 100.0%, 100.0% and 83.3% respectively when ADC≤1.25×10-3 mm2/s was used as a cutoff value for differential diagnosis of SPTP from PET. Conclusion Compared to normal pancreatic tissue, pancreatic cancer usually had a lower Ktrans, Kep and larger Ve. ADC values from respiratory-triggered DWI were well related to histopathological features of pancreatic entities and may be helpful in the differential diagnosis.     

螺旋CT双期扫描在钝性肾损伤中的应用

随着诊断技术的不断提高,对钝性肾损伤的保守治疗逐渐增多,螺旋CT双期扫描检查不仅能确定损伤的程度、范围,而且还能发现外伤后引起的肾血管性病变及观察损伤肾脏的肾功能改变,具有重要的临床意义。1资料与方法本组15例,男12例,女3例。年龄23～65岁(平均31.3岁),外伤原因:车祸撞伤11例,跌伤4例。就诊时间为1～40小时。其中临床表现为肉眼血尿10例,镜下血尿4例,无尿1例。伤后均表现为腰部疼痛、叩击痛,另有休克2例。用PICKULTRAZ螺旋CT扫描机,层厚10mm,层距10mm。15例均用螺旋CT平扫及双期增强扫描。对于扫描中发现合并腹腔其他脏器损…     

3.0T磁共振不同DWI序列在正常胰腺中的分析评价

目的：分析比较3.0T磁共振不同DWI序列在正常胰腺中的伪影及信噪比（SNR）。方法：在3.0T磁共振上,30例正常志愿者行常规T1WI、频率饱和脂肪抑制T2WI,MRCP,DWI及LAVE平扫,DWI序列均基于SE-EPI序列及b值为0和600 s/mm2,包括X、Y、Z三轴弥散梯度憋气DWI（BH600ALL）、Z轴弥散梯度憋气DWI（BH600SI）、呼吸门控DWI（TRIG600）、呼吸门控翻转恢复脂肪抑制DWI（TRIG600+BS）、自由呼吸翻转恢复脂肪抑制DWI（FB600+BS）及憋气翻转恢复脂肪抑制DWI（BH600ALL+BS）,统计学比较分析不同DWI序列正常胰腺伪影评分值及SNR。结果：正常胰腺在TRIG600+BS序列伪影评分最低,胰腺轮廓清晰,呈均匀低信号,FB600+BS胰腺轮廓模糊,TRIG600胰腺多呈不均匀高信号,憋气背景抑制DWI伪影评分最高,单因素方差分析统计学有明显差异,P＜0.001。正常胰腺在BH600ALL,BH600SI,TRIG600,TRIG600+BS,FB600+BS和BH600+BS六个DWI序列上的SNR有明显统计学差异,P＜0.001,其中TRIG600序列的SNR最高,BH600+BS序列最低;在不同DWI序列中,胰头、胰体及胰尾的SNR逐渐增加,胰头与胰尾的SNR有统计学差异,P＜0.05。结论：在3.0T MR仪上,TRIG600+BS中胰腺呈均匀一致低信号,轮廓清晰,图像质量优于其它五个DWI序列。     

扩散加权成像在预测肝细胞肝癌微血管浸润的价值

目的 评价扩散加权成像(DWI)对预测肝细胞肝癌微血管浸润的价值.方法 搜集46例肝癌患者的DWI资料,测量肿瘤表观扩散系数(ADC).比较微血管浸润阳性组和微血管浸润阴性组肝癌的ADC值,并进一步采用受试者工作特征曲线(ROC)分析ADC评价微血管浸润检测的诊断性能.结果 46例肝癌患者中24例微血管浸润阳性,22例微血管浸润阴性.微血管浸润阳性组的肝癌的ADC值低于微血管浸润阴性组,并具有统计学差异(1.22 ×10-3mm2/s,1.54×1O-3mm2/s,P=0.0004).应用ADC判断微血管浸润的曲线下面积(AUC)为0.78.以≤1.33×10-3mm2/s为界值判断肝癌存在微血管浸润的敏感性为75.0％,特异性为68.2％,阳性预测值为72.0％,阴性预测值为71.4％.结论 ADC值对于预测肝癌存在微血管浸润有潜在的价值.     

一例罕见胆总管粒细胞肉瘤的影像表现

患者男,45岁.皮肤、巩膜黄染伴尿色加深1个月于2009年1月24日入院.体检:巩膜、皮肤轻度黄染;右上腹压痛,并可扪及肿大胆囊.实验室检查:总胆红素为43.2 μmol/L(正常参考值:3.4～17.1 μmol/L),结合胆红素为35.2μmol/L(0～6.8 μmol/L),黄疸指数为87.0(<40.0).     

肾上腺嗜铬细胞瘤的MSCT表现特点

目的 分析肾上腺嗜铬细胞瘤的MSCT表现及其动态增强特征,以提高其诊断准确性.方法 回顾性分析经手术病理证实的肾上腺嗜铬细胞瘤15例,术前经多排螺旋CT平扫、动脉期和门脉期扫描.仔细复习CT扫描结果和手术病理作对照分析.结果 15例肾上腺嗜铬细胞瘤中,位于左侧肾上腺6例,右侧肾上腺8例,双侧肾上腺1例.肿瘤直径1.5～...     

肝细胞特异性对比剂普美显对结直肠癌肝转移的显示能力研究

目的与CT增强检查对比,评价普美显增强MRI对结直肠癌肝转移的显示能力及其对化疗后引起的脂肪肝肝功能的评估潜能。方法 25例结直肠癌肝转移化疗后患者,术前分别行普美显增强MRI及CT增强扫描,以病灶显示质量指数、病灶诊断敏感性、特异性、阳性预测值、阴性预测值、诊断准确率为指标进行评价,重点比较两种检查方法的差异性;并以正常肝实质背景肝胆特异期T1信号值作对比,测定化疗后肝胆特异期T1信号值,比较两者之间的差异性。结果 25例结直肠癌肝转移患者共57个病灶。普美显增强MRI检查检出病灶60个,肝胆特异期皆呈低信号。CT增强检查检出病灶40个,门脉期皆呈低密度。普美显增强MRI及CT增强对于肝转移灶的病灶显示质量指数,病灶诊断敏感性、特异性、阳性预测值、阴性预测值、诊断正确率分别为108分、95%、95%、100%、95%及62分、63.2%、63.2%、36.8%、63.2%,普美显增强MRI均优于CT增强;化疗后脂肪肝患者肝胆特异期肝实质平均T1信号值236.9±23.45 ms,正常对照组肝胆特异期肝实质平均T1信号值371.9±48.69 ms,两者具有统计学差异。结论普美显增强MRI较CT增强检查能更好的显示及诊断结直肠癌的肝转移灶,并具有一定评估肝实质背景肝功能的潜能,提高患者手术的成功率及延长患者术后的生存率。     

磁共振评价模型猪心肌缺血的ROC曲线分析

 目的 针对多种心脏MR检查方法进行不同组合联用,评价各种方法对慢性缺血心肌的检出率,探寻适合临床运用的最优组合。方法 选择左旋支放置Ameroid环制作慢性心肌缺血模型猪成功者13只。以冠状动脉造影结果及病理电镜组织学为标准,缺血心肌节段的检出分别采用单纯静息心脏电影(Cine)、静息首过灌注(FPrest)、负荷首过灌注(FPstress)、延迟增强(DE-MR)、静息负荷双期灌注(FP-dual-phase)、静息心脏电影+负荷灌注(Cine+FPstress) 多种评价方法。分别在不同方法下对各心肌节段诊断的确定性评分,用于ROC曲线分析。结果 各检查中以Cine+FPstress组合的灵敏度、特异度及曲线下面积均最大,分别为0.903、0.887和0.9273,与其他各组间差异存在统计学意义（P<0.05）。结论 静息电影联合负荷心肌灌注扫描检测心肌缺血的准确性最高,适用于临床,尤其对疑似冠心病的患者检出有帮助。