Endorectal ultrasonography versus phased-array magnetic resonance imaging for preoperative staging of rectal cancer

AIM： To compare the diagnostic accuracy of pelvic phased-array magnetic resonance imaging （MRI） and endorectal ultrasonography （ERUS） in the preoperative staging of rectal carcinoma.
METHODS： Thirty-four patients （15 males, 19 females） with ages ranging between 29 and 75 who have biopsy proven rectal tumor underwent both MRI and ERUS examinations before surgery. All patients were evaluated to determine the diagnostic accuracy of depth of transmural tumor invasion and lymph node metastases. Imaging results were correlated with histopathological findings regarded as the gold standard and both modalities were compared in terms of predicting preoperative local staging of rectal carcinoma.
RESULTS： The pathological T stage of the tumors was： pT1 in 1 patient, pT2 in 9 patients, pT3 in 21 patients and pT4 in 3 patients. The pathological N stage of the tumors was： pN0 in 19 patients, pN1 in 9 patients and pN2 in 6 patients. The accuracy of T staging for MRI was 89.70% （27 out of 34）. The sensitivity was 79.41% and the specificity was 93.14%. The accuracy of T staging for ERUS was 85.29% （24 out of 34）. The sensitivity was 70.59% and the specificity was 90.20%. Detection of lymph node metastases using phased-array MRI gave an accuracy of 74.50% （21 out of 34）. The sensitivity and specificity was found to be 61.76% and 80.88%, respectively. By using ERUS in the detection of lymph node metastases, an accuracy of 76.47% （18 out of 34） was obtained. The sensitivity and specificity were found to be 52.94% and 84.31%, respectively.
CONCLUSION： ERUS and phased-array MRI are complementary methods in the accurate preoperative staging of rectal cancer. In conclusion, we can state that phased-array MRI was observed to be slightly superior in determining the depth of transmural invasion （T stage） and has same value in detecting lymph node metastases （N stage） as compared to ERUS.     

Role of endoscopic ultrasonography in the loco-regional staging of patients with rectal cancer

The prognosis of rectal cancer (RC) is strictly related to both T and N stage of the disease at the time of diagnosis. RC staging is crucial for choosing the best multimodal therapy: patients with high risk locally advanced RC (LARC) undergo surgery after neoadjuvant chemotherapy and radiotherapy (NAT); those with low risk LARC are operated on after a preoperative short-course radiation therapy; finally, surgery alone is recommended only for early RC. Several imaging methods are used for staging patients with RC: computerized tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound (EUS). EUS is highly accurate for the loco-regional staging of RC, since it is capable to evaluate precisely the mural infiltration of the tumor (T), especially in early RC. On the other hand, EUS is less accurate in restaging RC after NAT and before surgery. Finally, EUS is indicated for follow-up of patients operated on for RC, where there is a need for the surveillance of the anastomosis. The aim of this review is to highlight the impact of EUS on the management of patients with RC, evaluating its role in both preoperative staging and follow-up of patients after surgery.     

Comparative study of transrectal ultrasonography, pelvic computerized tomography, and magnetic resonance imaging in preoperative staging of rectal cancer

PURPOSE: The preoperative assessment of rectal cancer wall invasion and regional lymph node metastasis is essential for the planning of optimal therapy. This study was done to determine the accuracy and clinical usefulness of transrectal ultrasonography, pelvic computed tomography, and magnetic resonance imaging in preoperative staging. METHODS: A total of 89 patients with rectal cancer were examined with transrectal ultrasonography (n=89), pelvic computed tomography (n=69), and magnetic resonance imaging with endorectal coil (n=73). The results obtained by these diagnostic modalities were compared with the histopathologic staging of specimens. RESULTS: In staging depth of invasion, the overall accuracy was 81.1 percent (72/89) by transrectal ultrasonography, 65.2 percent (45/69) by computed tomography, and 81 percent (59/73) by magnetic resonance imaging. Overstaging was 10 percent (9/89) by transrectal ultrasonography, 17.4 percent (12/69) by computed tomography, and 11 percent (8/73) by magnetic resonance imaging; and understaging was 8 of 89 (8.9 percent) by transrectal ultrasonography, 12 of 69 (17.4 percent) by computed tomography, and 6 of 73 (8 percent) by magnetic resonance imaging. In staging lymph node metastasis, the overall accuracy rate was 54 of 85 (63.5 percent) in transrectal ultrasonography, 39 of 69 (56.5 percent) in computed tomography, and 46 of 73 (63 percent) in magnetic resonance imaging. The sensitivity was 24 of 45 (53.3 percent) in transrectal ultrasonography, 14 of 25 (56 percent) in computed tomography, and 33 of 42 (78.5 percent) in magnetic resonance imaging; and specificity was 30 of 40 (75.0 percent) in transrectal ultrasonography, 25 of 44 (56.8 percent) in computed tomography, and 13 of 31 (41.9 percent) in magnetic resonance imaging. The accuracy in detection of positive lateral pelvic lymph nodes under magnetic resonance imaging (n=8) was 12.5 percent. The accuracy in detection of posterior vaginal wall invasion was 100 percent in transrectal ultrasonography (n=7) and 100 percent in magnetic resonance imaging (n=3), but 28.5 percent in computed tomography (n=7). CONCLUSIONS: Both transrectal ultrasonography and magnetic resonance imaging with endorectal coil exhibited similar accuracy and were superior to conventional computed tomography in preoperative assessment of depth of invasion and adjacent organ invasion. Because transrectal ultrasonography is a safer and more cost-effective modality than magnetic resonance imaging, transrectal ultrasonography is an appropriate method for preoperative staging of rectal cancer. Further efforts will be needed to provide a better staging of lymph node involvement.Read at the meeting of The American Society of Colon and Rectal Surgeons, San Antonio, Texas, May 2 to 7, 1998.     

Linear endoscopic ultrasonography vs magnetic resonance imaging in ampullary tumors

AIM:To assess linear endoscopic ultrasound (L-EUS) and magnetic resonance imaging (MRI) in biliary tract dilation and suspect small ampullary tumor.METHODS:L-EUS and MRI data were compared in 24 patients with small ampullary tumors;all with subsequent histological confirmation.Data were collected prospectively and the accuracy of detection,histological characterization and N staging were assessed retrospectivelyusing the results of surgical or endoscopic treatment as a benchmark.RESULTS:A suspicion of ampul...     

直肠癌术前磁共振水成像检查的意义

目的:探讨磁共振(MRI)水成像(MRH)对直肠癌术前诊断和分期的价值.方法:对临床确诊为直肠癌的患者34例进行MRI水成像检查,检查前经直肠注入生理盐水300 mL左右,先作盆腔常规轴位平扫,再作磁共振直肠水成像扫描,扫描完后再作轴位、矢状位和冠状位增强扫描.结果:34例直肠癌均能显示原发病灶,三维成像病变部位肠腔内不规则充盈缺损32例.19例病变远侧端呈"袖口征"及"截断征".轴位30例表现为腔内软组织肿块,26例表现为肠壁不规则增厚,肠腔环形狭窄.MRI水成像检查对T1,T2,T3,T4期肿瘤的准确度分别为66.7%(2/3),76.9%(10/13),86.7%(13/15),100%(3/3),总准确性为82.4%(284);判断淋巴结转移的敏感性、特异性和准确性分别为69.2%(18/26),62.5%(5/8),67.6%(23/34);对邻近组织脏器浸润、远处转移判断的准确度分别为94.1%(32/34)、97.1%(33/34).结论:MRI水成像加常规平扫加增强扫描对直肠癌的诊断和分期有较大价值,可以较准确地判断肿瘤在肠壁的浸润深度及盆腔内淋巴结的转移.     

Endoscopic ultrasound and magnetic resonance imaging for re-staging rectal cancer after radiotherapy

AIM: To compare the sensitivity and specificity of two imaging techniques, endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI), in patients with rectal cancer after neoadjuvant chemoradiation therapy.And we compared EUS and MRI data with histological findings from surgical specimens.METHODS: Thirty-nine consecutive patients (51.3% Male; mean age: 68.2 ± 8.9 years) with histologically confirmed distal rectal cancer were examined for staging.All patients underwent EUS and MRI imaging beforeand after neoadjuvant chemoradiation therapy.RESULTS: After neoadjuvant chemoradiation, EUS and MRI correctly classified 46% (18/39) and 44% (17/39) of patients, respectively, in line with their histological T stage ( P > 0.05). These proportions were higher for both techniques when nodal involvement was considered:69% (27/39) and 62% (24/39). When patients were sorted into T and N subgroups, the diagnostic accuracy of EUS was better than MRI for patients with T0-T2 (44% vs 33%, P > 0.05) and N0 disease (87% vs 52%, P = 0.013). However, MRI was more accurate than EUS in T and N staging for patients with more advanceddisease after radiotherapy, though these differencesdid not reach statistical significance.CONCLUSION: EUS and MRI are accurate imaging techniques for staging rectal cancer. However, after neoadjuvant RT-CT, the role of both methods in the assessmentof residual rectal tumors remains uncertain.     

Multimodal imaging evaluation in staging of rectal cancer

Rectal cancer is a common cancer and a major cause of mortality in Western countries.Accurate staging is essential for determining the optimal treatment strategies and planning appropriate surgical procedures to control rectal cancer.Endorectal ultrasonography(EUS)is suitable for assessing the extent of tumor invasion,particularly in early-stage or superficial rectal cancer cases.In advanced cases with distant metastases,computed tomography(CT)is the primary approach used to evaluate the disease.Magnetic resonance imaging(MRI)is often used to assess preoperative staging and the circumferential resection margin involvement,which assists in evaluating a patient’s risk of recurrence and their optimal therapeutic strategy.Positron emission tomography(PET)-CT may be useful in detecting occult synchronous tumors or metastases at the time of initial presentation.Restaging after neoadjuvant chemoradiotherapy(CRT)remains a challenge with all modalities because it is difficult to reliably differentiate between the tumor mass and other radiation-induced changes in the images.EUS does not appear to have a useful role in post-therapeutic response assessments.Although CT is most commonly used to evaluate treatment responses,its utility for identifying and following-up metastatic lesions is limited.Preoperative high-resolution MRI in combination with diffusion-weighted imaging,and/or PET-CT could provide valuable prognostic information for rectal cancer patients with locally advanced disease receiving preoperative CRT.Based on these results,we conclude that a combination of multimodal imaging methods should be used to precisely assess the restaging of rectal cancer following CRT.     

直肠类癌的内镜超声图像特征

目的探讨直肠类癌的内镜超声(EUS)图像特征，以提高其诊断正确率。方法连续收集2001年4月至2004年4月直肠黏膜及黏膜下肿物29例，行EUS检查及病理检查，分析经病理确诊的直肠类癌的EUS图像，找出其特征性表现。结果29例共检出病灶29个，其中类癌12个，腺瘤11个，炎性病灶6个。直肠类癌病灶中10个呈低回声结节，2个呈等回声；5个病灶位于黏膜层，7个位于黏膜下层；12个病灶边界均清晰。结论直肠类癌的EUS声像图特征是：病灶边界清，回声均匀，位于黏膜下层或黏膜层，绝大多数呈低回声结节。EUS声像图特征有助于直肠类癌的早期诊断。     

MRI检查在直肠癌诊断与术前分期的应用研究

目的探讨3.0T MRI对直肠癌患者术前判断T、N分期以及测量直肠肿瘤下缘与肛缘间曲线距离的准确性。 方法经术前肠镜活检病理证实为直肠癌的患者53例,于术前行MRI扫描,进行T、N分期并测量肿瘤下缘与肛缘间的距离。以术后病理结果为标准,验证3.0T MRI评价肿瘤T、N分期的准确性;用MRI测量出的肿瘤下缘与肛缘曲线的距离与手术标本测量的结果相比较,找出两种结果的相关性。 结果MRI对直肠癌患者T、N分期判定的准确率分别为83.1%、67.9%,统计学分析显示与病理结果有较好的一致性。MRI测量肿瘤下缘与肛缘的曲线距离与手术标本测得的数值无明显统计学差异。 结论MRI对直肠癌患者术前T、N分期的判定以及测量肿瘤下缘与肛缘间的曲线距离有较高的准确性,对术前治疗及手术方式的选择有很好的指导意义。     

超声内镜对胃癌术前分期的诊断价值

目的评估超声内镜在胃癌术前分期的价值。方法 75例经胃镜及病理证实的胃癌患者于术前进行超声内镜检查,并与术后组织病理分期比较。结果超声内镜分期结果与病理学分期结果比较,超声内镜对胃癌术前T分期判断的准确率为82.7%、N分期判断的准确率为86.7%。结论超声内镜能较准确地判断胃癌分期,有助于制订合理的手术方案。     

Usefulness of endoscopic ultrasonography in preoperative TNM staging of gastric cancer

AIM:To evaluate the value of endoscopic ultrasono-graphy (EUS) in the preoperative TNM staging of gastriccancer.METHODS :Forty-one patients with gastric cancer(12 early stage and 29 advanced stage) provedby esophagogastroduodenoscopy and biopsiespreoperatively evaluated with EUS according to TNM(1997) classification of International Union ContreleCancer (UICC).Pentax EG-3630U/Hitachi EUB-525 echoendoscope with real-time ultrasound imaging linearscanning transducers (7.5 and 5.0 MHz) and Dopplerinformation was used in the current study.EUS stagingprocedures for tumor depth of invasion (T stage) wereperformed according to the widely accepted five-layerstructure of the gastric wall.All patients underwentsurgery.Diagnostic accuracy of EUS for TNM stagingof gastric cancer was determined by comparingpreoperative EUS with subsequent postoperativehistopathologic findings.RESULTS:The overall diagnostic accuracy of EUS inpreoperative determination of cancer depth of invasionwas 68.3% (41128) and 83.3% (12110),60% (20112),100% (5/5),25% (4/1) for T1,T2,T3,and T4,respectively.The rates for overstaging and understagingwere 24.4% (41/10),and 7.3% (41/3),respectively.EUStended to overstage T criteria,and main reasons foroverstaging were thickening of the gastric wall due toperifocal inflammatory change,and absence of serosallayer in certain areas of the stomach.The diagnosticaccuracy of metastatic lymph node involvement or Nstaging of EUS was 100% (17/17) for NO and 41.7%(24/10) for N ,respectively,and 66% (41/27) overall. Misdiagnosing of the metastatic lymph nodes was relatedto the difficulty of distinguishing inflammatory lymphnodes from malignant lymph nodes,which imitate similarecho features.Predominant location and distribution oftumors in the stomach were in the antrum (20 patients),and the lesser curvature (17 patients),respectively.Three cases were found as surgically unresectable (T4 N ),and included as being correctly diagnosed by EUS.     

Transrectal ultrasonography and magnetic resonance imaging in the staging of rectal cancer. Effect of experience

Objective. To evaluate the effect of experience on preoperative staging of rectal cancer using magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS). Material and methods. From January 2002 to May 2006, 134 consecutive patients with biopsy-proven rectal cancer were examined with a 1.5-Tesla MRI unit and TRUS using a 6.5-MHz transducer. An experienced gastrointestinal radiologist (R1) or a general radiologist (R2) performed the evaluations. All patients (78 M, 56 F, mean age 69.1 years, range 38–89) were treated with surgery alone. The mean size of the tumour was 4.0 cm (range 1.1–7.5). A complete postoperative histopathological examination was used as the gold standard. Results. At pathology, 42 of 134 (31%) tumours were classified as T1-T2 and 92 (69%) were classified as T3-T4. The TRUS sensitivity in rectal tumour T-staging was 93% for R1 and 75% for R2 (p<0. 01); specificity was 83% for R1 and 46% for R2 (p<0.05). The MRI sensitivity in rectal tumour T-staging was 96% for R1 and 77% for R2 (p<0. 05); the specificity was 74% for R1 and 40% for R2 (p<0.05). There was no difference in the results of N-staging between R1 and R2 for either TRUS or MRI. Conclusion. Reader experience had a statistically significant positive effect on the preoperative prediction of tumour involvement of the rectal wall. To obtain high-quality preoperative prediction of rectal cancer T-stage, it is suggested that preoperative TRUS and MRI staging should be supervised by an expert in the colorectal cancer team. In addition to this supervision, the person responsible for staging should be trained through a defined training programme.     

线阵超声内镜对直肠子宫内膜异位症的诊断价值

目的:探讨线阵超声内镜对直肠子宫内膜异位症(rectal endometriosis,RE)的诊断价值.方法:对20例子宫内膜异位症患者于外科手术前行线阵超声内镜检查直肠,超声扫描频率为7.5MHz,根据直肠壁内有无边界不规则的低回声结节或团块判断直肠是否受累,并将超声内镜检查结果与手术中所见及术后病理进行比较.结果:20例患者中有12例经线阵超声内镜检查发现直肠壁内有异位子宫内膜病灶,其余8例患者的直肠壁正常.超声内镜诊断为RE的12例患者术中均见盆腔异位子宫内膜病灶与肠壁粘连紧密,手术切除的直肠病灶送检均见子宫内膜组织.超声内镜下未见直肠受累的8例患者盆腔子宫内膜异位病灶与肠壁无粘连或轻度粘连,易分离,分离缘组织送检未见子宫内膜组织.线阵超声内镜检查结果与手术中所见及术后病理完全一致.结论:线阵超声内镜检查是诊断RE的可靠方法,可对子宫内膜异位症患者是否伴有直肠受累做出准确的术前评估.     

Preoperative staging of rectal carcinoma by computed tomography and 0.15T magnetic resonance imaging

A prospective study was done on 34 patients using magnetic resonance imaging (MRI) and computed tomography (CT) preoperatively to stage patients with known rectal carcinoma. The study was done to determine the accuracy and clinical usefulness of CT and MRI. The Thoeni staging method was used. Twenty-four of 30 cases were staged correctly by CT. Sixteen of 27 were staged correctly by MRI. CT detected lymph node metastases in six of 15 cases with one false-positive. MRI detected lymph node metastases in two of 15 patients with one false-positive. CT was the preferred examination, and was useful in some cases. These cases included patients with small tumors who were considered for local excision and patients with extensive disease who were candidates for preoperative or intraoperative radiation treatment. MRI demonstrated extensive disease, as did CT in our later cases. Read at the meeting of the American Society of Colon and Rectal Surgeons, San Diego, California, May 5 to 10, 1985.     

Identification of the fascia propria by magnetic resonance imaging and its relevance to preoperative assessment of rectal cancer

PURPOSE: If rectal cancer does not penetrate the fascia propria of the rectum and the rectum is removed with the fascial envelope intact (extrafascial excision), then local recurrence of the cancer will be minimal. Modern imaging techniques have identified a fascial plane surrounding the rectum and mesorectum, and it has been suggested that this is the fascia propria. The aim of this study was to identify whether this plane is the rectal fascia propria and whether tumor invasion through this fascia can be identified preoperatively. METHODS: Two separate experiments were performed: 1) pelvic magnetic resonance imaging was performed before and after dissection and marking of the plane of extrafascial dissection of the rectum of a cadaver; and 2) magnetic resonance imaging was performed in 43 rectal cancer patients preoperatively. Two radiologists independently reported the depth of tumor invasion in relation to the fascia propria. The tumors were resected by extrafascial excision, and a pathologist independently reported the relation of the tumor to the fascia propria. RESULTS: The marker inserted in the extrafascial plane showed that the plane visualized on pelvic magnetic resonance imaging was the fascia propria dissected in extrafascial excision of the rectum. The magnetic resonance imaging detected tumor penetration through the fascia propria with a sensitivity of 67 percent, a specificity of 100 percent, and an accuracy of 95 percent. CONCLUSION: The surgical fascia propria can be identified on preoperative magnetic resonance imaging in patients with rectal cancer. Tumor invasion through this fascia can be detected on magnetic resonance imaging. This method of assessment offers a new way to select those patients who require preoperative radiotherapy.Supported by a research grant from The Maurice and Phyllis Paykel Trust, Parnell, Auckland, New Zealand.     

三维超声内镜评估直肠癌浸润深度的临床研究

目的 评估三维超声内镜(3D-EUS)在判断直肠癌浸润深度方面的准确性.方法 选择2007年5-11月经结肠镜及活检病理证实为原发性直肠癌的患者21例,术前由同一位超声内镜医师分别用同一超声探头进行二维超声内镜(2D-EUS)及3D-EUS检查,同时行直肠MRI检查,对其浸润深度进行分期判断,以术后病理结果 为金标准对上述3种检查方法 进行评估.结果 判断直肠癌浸润深度的准确率3D-EUS为85.71%,2D-EUS为76.19%,MRI为57.14%;3D-EUS的准确率明显高于MRI(P<0.05),与2D-EUS比较差异无统计学意义(P>0.05).结论 利用3D-EUS在判断直肠癌浸润深度方面的优势,结合MRI对淋巴转移的探查,可以更准确地判断直肠癌的术前分期,为直肠癌以手术为主的综合治疗提供丰富而准确的临床资料.     

超声检查与螺旋CT对胃癌术前TNM分期准确性的meta分析

目的利用meta分析方法比较超声检查与螺旋CT对胃癌术前TNM分期的准确性。方法计算机检索PubMed(Med-line)、CBM、CNKI、VIP及万方数据库相关文章。按照事先制定的纳入、排除标准筛选文献、提取资料和进行方法学质量评价后,采用RevMan 5.0软件进行meta分析。结果共纳入15个临床试验,合计1 019例患者。meta分析结果显示:①超声检查及螺旋CT对于T3和N3期的判断的准确率接近;②对于T1、T2和N0期的判断超声检查明显优于螺旋CT;③对于T4、N1、N2和M期的判断螺旋CT明显优于超声检查。结论超声检查对胃癌术前T1、T2分期及N0分期具有较高的临床应用价值,而螺旋CT对于远处淋巴结转移的分期及M分期的准确性较高。     

A comparison of transanal excision and endoscopic resection for early rectal cancer

AIM: To compare the outcomes of endoscopic resection with transanal excision in patients with early rectal cancer.METHODS: Thirty-two patients with early rectal cancer were treated by transanal excision or endoscopic resection between May 1999 and December 2007. The patients were regularly re-examined by means of colonoscopy and abdominal computed tomography after resection of the early rectal cancer. Complications, length of hospital-stay, disease recurrence and follow up outcomes were assessed.RESULTS: Sixteen patients were treated by endoscopic resection and 16 patients were treated by transanal excision. No significant differences were present in the baseline characteristics. The rate of complete resection in the endoscopic resection group was 93.8%, compared to 87.5% in the transanal excision group (P = 0.544). The mean length of hospital-stay in the endoscopic resection group was 2.7 ± 1.1 d, compared to 8.9 ± 2.7 d in the transanal excision group (P = 0.001). The median follow up was 15.0 mo (range 6-99). During the follow up period, there was no case of recurrent disease in either group.CONCLUSION: Endoscopic resection was a safe and effective method for the treatment of early rectal cancers and its outcomes were comparable to those of transanal excision procedures.     

State-of-the-art preoperative staging of gastric cancer by MDCT and magnetic resonance imaging

Gastric cancer is one of the most common and fatal cancers.The importance of accurate staging for gastric cancer has become more critical due to the recent introduction of less invasive treatment options,such as endoscopic mucosal resection or laparoscopic surgery.The tumor-node-metastasis staging system is the generally accepted staging system for predicting the prognosis of patients with gastric cancer.Multidetector row computed tomography(MDCT)is a widely accepted imaging modality for the preoperative staging of gastric cancer that can simultaneously assess locoregional staging,including the gastric mass,regional lymph nodes,and distant metastasis.The diagnostic performance of MDCT for T-and N-staging has been improved by the technical development of isotropic imaging and 3D reformation.Although magnetic resonance imaging(MRI)was not previously used to evaluate gastric cancer due to the modality’s limitations,the development of high-speed sequences has made MRI a feasible tool for the staging of gastric cancer.