中图号:R737.11;R730.44文献标识码:A文章编号:1000-467X(1999)s0-0087-04
Helical CT scan: Application in the diagnosis
of reno- cellular carcinoma
GUO Yan, HUANG Zhao-min, LIU Min-juan, et al.
Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University
of Medical Sciences, Guangzhou 510080, P.R.China
【Abstract】Objective: This is an evaluation of the helical CT scan in the diagnosis of reno-cellular carcinoma.Methods: Helical CT scan was performed in 40 patients with reno-carcinoma to obtain the characteristic CT findings, and 36 cases out of 40 had been surgically proved.Results: In 36 cases of progressive reno-carcinoma helical CT scan showed in cortical phase: equal or higher enhancement of nidi than that of normal cortex, while in 8 cases the tumor enhancement is lower than that of cortex and higher than that of medulla, and the rest 2 cases were represented with the equal or lower enhancement than that with the medulla. We had 4 cases of small reno-carcinoma, and in the cortical phase 3 had tumor enhancement equal to or higher than that of cortex, and the other 1 had enhancement between the cortex and medulla. In 2 cases of cystic reno carcinoma, helical CT scan demonstrated that the enhancement of wall and nodules was between the cortex and medulla. In another case the wall and nodules were irregularly and equally enhanced in cortical phase, while the enhancement was weakened in the late cortical phase and the following parenchymal phase. Conclusion: The multi-phasic helical CT scan is superior to the conventional CT in the diagnosis of reno-carcinoma, especially of small reno-carcinoma. In most of the cases the tumor enhancement is strong in cortical phase but weak in late cortical phase and parenchymal phase, which is a characteristic pattern of enhancement. And we belives those features of enhancement has diagnostic significance in differential diagnosis.
Key Words: Reno-cellular carcinoma; Tomography; X ray Computer
肾细胞癌(renalcellcarcinoma,简称肾癌)是泌尿系统最常见的恶性肿瘤,随着现代医学影像技术的迅速发展和广泛应用,肾癌的检出率明显提高。笔者通过对40例肾癌的螺旋CT表现分析,评价螺旋CT多期扫描在肾癌诊断中的应用价值。
1材料与方法
本院1996年10月至1999年3月资料完整的肾细胞癌40例,其中男23例,女17例。年龄最小15岁,最大81岁,平均49岁。34例经手术病理证实,6例出现远处器官转移,结合临床资料诊断证实。12例无临床症状,常规体检B超发现肾肿块,12例主诉腰痛不适;11例出现无痛性肉眼血尿;其它症状有腹部包块2例、下肢痛1例、双下肢浮肿1例、发作性血压升高1例、咯血1例、发热1例。
使用ToshibaXpress/SX型螺旋CT机,病人按常规禁食8小时,检查前0.5~1小时口服3%的泛影葡胺对比剂1000ml充盈胃肠道。先作双肾常规平扫或螺旋扫描,增强时用高压注射器从肘前静脉内注射60%的碘造影剂50~70ml(或按1~1.5ml/kg体重计算),速率2.5~3ml/S,注射完毕后30秒开始作全肾脏皮质期增强扫描,曝光条件为电压120KV,250~300mAS,床进速度10mm/S,层厚10mm,螺距为1.0,注射后60~90秒,以同样条件作肾脏实质期增强扫描,注射后4~5分钟作肾盂期扫描,扫描期间病人均应在平静呼吸状态下屏气。
2结果
40例中小肾癌4例,囊性肾癌2例,进展期肾癌34例。癌肿最大径≤3cm者4例,>3~6cm者12例,>6~9cm者13例,>9cm者11例。7例向肾外生长,9例向肾窦生长,20例既向肾外同时向肾窦浸润,4例小肾癌局限肾实质内。
肾癌螺旋CT表现:
进展期肾癌34例。平扫17例呈等密度,7例呈高混杂密度,10例呈低混杂密度。16例病灶内见大小不等片状坏死。14例出现钙化,其部位、形态不一,病灶中心出现散在钙化点5例,边缘包壳状、弧状、斑块状钙化5例,病灶整体出现条、片状钙化1例,病灶内部分有密集的弧状、点状钙化而部分无钙化者3例,1例肾静脉癌栓出现钙化。增强扫描皮质期24例强化程度高或等于正常肾皮质,其中2例病灶全瘤弥漫强化(图1,2),22例局灶性强化;8例强化低于肾皮质但高于髓质,除1例弥漫性强化外余均呈局灶性强化;2例强化等或低于正常髓质。实质期和肾盂期肿瘤强化明显减弱。34例中25例未发现转移灶,此组病灶平扫19例边界不清,6例边界清楚,增强扫描12例部分边缘清部分不清,13例边缘清晰有假包膜;9例发生转移的病例中(腔静脉癌栓、肾静脉癌栓、肾门及腹膜后淋巴结增大、远处器官转移)平扫肿瘤边缘均不清楚,增强扫描5例边界清楚但不规则,4例边界不清。患侧肾盂盏受压推移、破坏23例。肾包膜及肾周脂肪间隙见小结节状、不均匀条索状影10例。肾后筋膜、腰大肌受累3例。肾静脉癌栓5例,其中2例同时出现肾静脉为肿物包埋征象。下腔静脉癌栓4例,病侧肾门淋巴结增大7例,腹膜后淋巴结增大7例,病侧肾上腺转移1例,双侧肾上腺转移2例,纵隔淋巴结转移1例,腰椎转移1例。
图1左侧进展期紧癌CT平扫
图2(同上例),螺旋CT增强扫描皮质期全瘤弥漫性强化,强化程度高于肾皮质
小肾癌4例。平扫3例呈等密度,1例为低混杂密度,4例边缘均不清楚。增强扫描3例皮质期强化程度高或等于正常肾皮质,2例为全瘤强化,2例局灶强化,1例局灶强化中的强化低于皮质但高于髓质。实质期及肾盂期强化减弱(图3、4、5、6)。3例强化后边缘清楚但不规则,1例边缘清晰有假包膜。
图3左侧小肾癌,CT平扫瘤灶呈等密度
图4(同上例),螺旋CT增强扫描全瘤强化,皮质期肿瘤强化程度等于肾皮质
图5、图6(同上例)实质期及肾盂期肿瘤强化减弱
囊性肾癌2例。1例CT平扫呈厚壁囊肿状,囊壁不光滑且见较厚不规则的短嵴及结节影,边界不清。增强扫描皮质期囊壁及短嵴强化程度低于正常肾皮质但高于髓质,边缘不规则。另1例呈多囊样改变,囊大小不一,囊壁及分隔不光滑,厚薄不一,边缘不规则。增强扫描皮质期囊壁及分隔强化均等于正常肾皮质(图7、图8),实质期及肾盂期强化减弱,边缘部分清楚部分不规则欠清楚,术前误诊为多囊性炎性病变。
图7右侧囊性肾癌,CT平扫
图8(同上例),螺旋CT增强扫描皮质期瘤灶囊壁及不规则分隔强化程度等于肾皮质
40例中正确诊断38例,误诊2例。
3讨论
3.1小肾癌螺旋CT表现
小肾癌(直径≤3cm)常于体检发现,螺旋CT<
