3.0T磁共振动态增强扫描在直肠病变的应用  

DCE-MRI of rectal diseases at 3T

作　　者：张晓明[1] 马祥兴[1] 于德新[1] 孟祥水[1] 李传福[1] 

机构地区：[1]山东大学齐鲁医院放射科,济南250012

出　　处：《山东大学学报（医学版）》2011年第4期118-122,128,共6页Journal of Shandong University:Health Sciences

基　　金：山东省卫生厅青年基金项目(2005JW017)

摘　　要：目的探讨直肠病变3T磁共振动态增强扫描的特点及其在诊断中的价值。方法对51例直肠癌及直肠周围病变患者的磁共振动态增强扫描图像进行回顾性分析。使用3T双梯度短磁体全身磁共振系统,8通道相控阵表面线圈。应用3D F-SPGR序列,对比剂注射速度3 mL/s,注射剂量0.1 mmol/kg,自对比剂开始注射时启动动态增强扫描,15～20个扫描时相不间断连续进行,总扫描时间4～6 min。分析不同直肠病变及不同分化程度、TNM分期的直肠癌的时间-信号强度曲线,测量病变强化达峰值时的信号强度(SIpeak),获取达峰值的时间(Tpeak)并进行比较。结果将直肠病变的时间-信号强度曲线根据强化峰值出现的早晚及对比剂退出的情况分为A、B、C、D 4种类型。直肠腺瘤均为A型,直肠癌术后复发和肛周脓肿峰值出现较晚,均属B、C、D型。直肠癌表现不一,且随分化级别的降低,时间-信号强度曲线的形态渐由A型向D型转化。各类直肠病变的Tpeak差别显著(P<0.05),由早到晚依次为直肠腺瘤、直肠癌、肛周脓肿和直肠癌术后复发。随分化级别的降低,浸润深度的增加,Tpeak逐渐延长。未穿透浆膜层的直肠癌Tpeak明显早于穿透浆膜层的直肠癌(P<0.05),无淋巴结转移的直肠癌Tpeak明显早于有淋巴结转移的直肠癌(P<0.05)。结论不同的时间-信号强度曲线形态对于直肠病变的诊断有帮助,Tpeak可作为直肠癌诊断、鉴别诊断和预后预测的较为可靠的指标。Objective To evaluate the feature of dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） at 3.0T for rectal diseases and to determine it＇s value. Methods DCE-MRI was performed on 51 patients with rectal diseases at 3.0T using 3D F-SPGR sequence. The contrast material was injected at the rate of 3 mL/s with a dose of 0.1 mmol/kg. DCE-MRI with 15-20 phases was consecutively performed once the injection of contrast media started. The time-intensity curve （TIC） was obtained and signal intensity of peak enhancement （SIpeak） and time to peak enhancement （ Tpeak ） of different rectal diseases and various degree of differentiation and TNM staging of rectal carcinoma were measured and compared. Results Four types were classified for TICs according to the time to enhancement peak and washing out of the contrast material. All of adenomas presented as type A, while local recurrence of rectal carcinoma and abscesses presented as B, C or D type. The TICs of rectal carcinoma were various and changed gradually from type A to type D with the worsening of differentiation. There were significant differences among the Tpeak in different diseases. The order of the Tpeak from early phase to late phase was adenoma, cancer, abscess and recurrence. The Tpeak became longer with the worsening of the differentiation of rectal carcinoma and depth of rectal carcinoma invasion. The Tpeak of rectal carcinoma without serosa invasion and lymph nodes metastasis was earlier than rectal carcinoma with such invasion and metastasis（ P 〈 0.05）. Conclusion TIC is helpful in the diagnosis of rectal diseases. The Tpeak is a reliable index for the diagnosis, differential diagnosis and prognosis prediction of rectal carcinoma.

关 键 词：直肠肿瘤 磁共振成像 动态增强 

分 类 号：R445.2[医药卫生—影像医学与核医学]