器官局限型膀胱尿路上皮癌:DCE-MRI早期“黏膜下强化线”征与DWI“蒂”征对照分析

Organ-confined urinary bladder carcinoma:a comparative analysis for “submucosal linear enhancement” sign on early phase of DCE-MRI and the “inchworm” sign on DWI

目的通过对膀胱尿路上皮癌的动态增强(DCE-MRI)"黏膜下强化线"征与DWI"蒂"征的对照分析,探讨黏膜下线的强化特征及其发生机制,进一步评价其对鉴别分期低于或为T_1期与T_2期膀胱癌的应用价值。方法本研究经医院伦理委员会批准,均已获得病人书面同意。59例已证实或可疑膀胱癌且无肾功能损害的患者纳入本研究。所有入组患者于我院接受了膀胱MR平扫、DWI及DCE-MRI,并于MRI检查后两周内行手术治疗。将MR图像分成2种组合:T_2WI加DWI、T_2WI加DCE-MRI。阅片者在不知病理结果的前提下分析肿瘤的征象,将DWI与DCE征象及病理分期对比分析。瘤灶的最大径亦进行了对比。结果 92个瘤灶纳入研究,DWI示42个肿瘤"有蒂",50个肿瘤"无蒂"。42个"有蒂"肿瘤于DCE图上38个可见黏膜下强化线并向瘤灶中央纠集(术后病理证实35个T_1期、3个T_2期),3个可见黏膜下强化线平直连续、未见纠集(均为T_1期),1个可见黏膜下强化线未见纠集、但中断(T_2期);50个"无蒂"肿瘤于DCE图像上34个未见明确黏膜下强化线(30个T_1期、4个T_2期),11个可见黏膜下强化线平直连续、未见纠集(10个T_1期、1个T_2期),4个可见黏膜下强化线未见纠集、但中断(1个T_1期、3个T_2期),1个可见黏膜下强化线向瘤灶中央纠集(T_2期)。结论 DCEMRI黏膜下强化线及其形态是鉴别分期低于或为T_1期与T_2期膀胱尿路上皮癌的一种重要征象。对于最大径小于10 mm的瘤灶,DCE未见明确黏膜下强化线常提示肿瘤未侵犯膀胱肌层;对于最大径大于10 mm的瘤灶,黏膜下强化线连续平直或向瘤灶中央纠集亦常提示肿瘤未侵犯膀胱肌层;黏膜下强化线中断提示肿瘤侵犯膀胱肌层。

Objective To analyze the ＂submucosal linear enhancement＂ sign on early phase of DCE-MRI and the ＂inchworm ＂sign on DWI for the pathogenetic mechanism and value in preoperative staging of organ confined bladder carcinoma. Methods 59 patients with suspected or confirmed urothelial bladder cancer and no renal function impairment were enrolled in the study..All patients underwent MRI within 2-weeks before surgery..Two image sets of T_2WIDW-MRI and T_2WIDCE-MRI were independently interpreted by two readers at 2-week intervals by analyzing whether there were. ＂inchworm ＂.sign on DWI and. ＂submucosal linear enhancement ＂.sign on early phase of DCE-MRI in comparison with pathology..Tumor size was also compared..Results 92 carcinomas with.（42）.and without.（50）.inchworm sign on DWI were analyzed..42 carcinomas with. ＂submucosal linear enhancement ＂.on early phase of DCE-MRI manifested as continuous linear enhanced submucosa gathering toward into the center of tumor（38, 35 stage T_1 and 3 stage T_2）, continuous straight and no gathering linear enhanced submucosa（3, all stage T_1）, or interrupted linear enhanced submucosa（1, stage T_2）. The remaining 50 lesions without inchworm sign included 34（30 stage T_1, 4 stage T_2） without linear enhanced submucosa, 11（10 stage T_1, 1 stage T_2） with continuous straight and no gathering linear enhanced submucosa, 4（1 stage T_1, 3 stage T_2） with interrupted linear enhanced submucosa, and 1（stage T_2） with continuous linear enhanced submucosa gathering toward into the center of tumor. Conclusion Presentation and manifestation of ＂submucosal linear enhancement ＂ under the tumor base on DCE-MRI is a significant imaging sign, which can be helpful in the differentiation of tumors in stage T_1 or lower versus those in stage T_2 bladder urothelial carcinoma. Tumors smaller than 10 mm without submucosal linear enhancement are often stage T_2. Tumors larger than 10 mm showing continuous submucosal linear enhancement either straight or gathering toward into the tumor center are stage T_1.