MSCT低张水灌肠技术在大肠癌诊断中的应用价值

目的：探讨MSCT低张水灌肠技术在大肠癌诊断中的应用价值。方法：选取临床和／或纤维结肠镜检查拟诊大肠癌患者70例作为研究对象（排除严重肠梗阻患者）。所有患者均行MSCT低张＋水灌肠＋体位扫描＋三期动态增强扫描。由2名高年资放射科医师阅片,重点观察病变部位、大小、形态、肠壁厚度及分层情况,病变强化特征,浆膜面改变,肠周脂肪间隙,邻近血管,淋巴结及远处脏器。防止遗漏小病灶。以术后病理TNM分期为金标准,采用诊断性试验,判断MSCT对大肠癌分期的敏感性、特异性及准确度。结果：70例大肠癌MSCT全部检出,病变位于升结肠13例,横结肠2例,降结肠3例,乙状结肠21例,直肠31例。本组61例低张水灌肠效果满意,较好显示病变部位、形态、长度及肠壁侵犯深度,9例肠管未充分扩张,肿瘤境界显示不满意,其中升结肠3例．肝曲结肠1例,直肠下段5例。病变处肠壁不规则增厚,部分肿块形成,最大约12．5cm×10．3cm。病变最长约15．0cm。病变不同程度强化．明显强化者占82．86％（58／70）,强化幅度平均为（43．5±15．7）HU。大肠癌TNM分期准确度为87．14％（61／70）．其中T分期准确度为88．57％（62／70）。N分期准确度为87．14％（61／70）,M分期准确度为90％（63／70）。结论：MSCT低张水灌肠技术能较清楚的显示病灶部位、大小、形态、长度、肠壁浸润深度。对大肠癌术前分期准确度较明显提高。但对于升结肠近端及直肠下段肿瘤病变显示有一定限度。     

Is there a role for (99m)Tc-anti-CEA monoclonal antibody imaging in the diagnosis of recurrent colorectal carcinoma?

AIM: To evaluate the usefulness of immunoscintigraphy with an anti-CEA monoclonal antibody fragment labelled with (99m)Tc for early detection of colorectal recurrence in patients with rising serum CEA levels. METHODS: Fifty-one consecutive patients (27 women, 24 men) with colorectal cancer (mean age 68.9+/-10.2 years) and rising CEA levels (16.2+/-18.2 ng/ml) were prospectively studied. Two immunoscintigraphy studies were performed in 8 patients (n=59). Immunoscintigraphy was performed after i.v. injection of 925 MBq of anti-CEA monoclonal antibody. Planar images of the thorax, abdomen and pelvis, as well as SPECT of the abdomen and pelvis were obtained at 4 and 24 hours after injection. In all cases an abdominal CT scan was previously performed. Findings were validated by histopathological analysis (28 cases) or by imaging and clinical follow-up of at least 6 months following the immunoscintigraphy (31 cases). RESULTS: Forty-one patients did not show recurrence during follow-up. We found 18 cases with confirmed diagnosis of extrahepatic abdominal or pelvic diseases, 11 cases with liver metastases, 9 in the thorax and 2 in the bone. In patients with pelvic and extrahepatic abdominal disease, immunoscintigraphy was positive in 18 cases (14 true positive, 4 false positive). From the 14 true positive only 7 cases had been detected by CT. Immunoscintigraphy was negative in the remaining 41 cases (37 true negative, 4 false negative). Therefore, the sensitivity and specificity for immunoscintigraphy in extrahepatic abdominal and pelvic disease were 78% and 90%, respectively. CT results showed a lower sensitivity of 61% (p<0.05) and specificity of 83%. Liver metastases were detected by CT in 9 cases, but only 2 of these were identified using immunoscintigraphy. CONCLUSION: Scintigraphy with anti-CEA monoclonal antibody fragment labelled with (99m)Tc is superior to CT for the detection of pelvic and extrahepatic abdominal recurrence of colorectal cancer, while CT is more sensitive in the detection of liver and lung metastases. Immunoscintigraphy has a limited usefulness in the detection of distant metastases, but it may be helpful in the diagnosis of suspected colorectal recurrence in patients with non-conclusive CT findings, when FDG-PET is not available.     

Computed tomography findings mimicking appendicitis as a manifestation of colorectal cancer

The primary computed tomography (CT) signs of appendicitis can also be seen with other inflammatory or neoplastic processes. We report on two cases in which appendiceal dilatation and peri-appendiceal fluid or stranding were the dominant imaging manifestations of colorectal carcinoma in the ascending colon. This study highlights the need to closely examine the ascending colon in patients with a suspected CT diagnosis of acute appendicitis, since these findings may be secondary to an inconspicuous colorectal carcinoma.     

Limitations in the CT diagnosis of acute diverticulitis: comparison of CT, contrast enema, and pathologic findings in 16 patients

Pitfalls in CT diagnosis of acute diverticulitis were investigated in 16 patients with the disease who had misleading or equivocal CT features. The CT appearance was correlated with contrast enemas (13 cases) and with surgical assessment and pathologic evaluation of resected specimens (12 cases). Limitations in the CT diagnosis were related to (1) marked thickening of the colonic wall, between 1 and 3 cm in cross section simulating colonic neoplasm (all patients); (2) inability to visualize small amounts of fibropurulent exudate in the absence of pericolic inflammatory changes (eight patients); (3) failure to detect discrete intramural abscess (five patients). Resected surgical specimens available in 12 cases proved that colonic wall thickening was caused by muscular hypertrophy and various degrees of submucosal inflammation, edema, fibrosis, or focal organized inflammatory tissue. Contrast enema was useful in 10 out of 13 patients by excluding carcinoma of the colon and confirming the diagnosis of acute diverticulitis.     

Ultrasonic diagnosis, staging and follow-up of prostatic neoplasms

120 patients with clinical suspected prostatic neoplasm were evaluate by transrectal linear sonography. 26 normal glands, 57 hypertrophic adenomas and 37 adenocarcinomas were recognized. We had 17 false positive cases for adenocarcinoma in hypertrophic adenomas. We had no false negatives. All diagnosis were confirmed bioptically, by CT or surgically. The findings of 37 adenocarcinomas are examined. The US criteria for early diagnosis (T1-T2), advantages and limits of transrectal linear probe in staging and follow-up, are discussed.     

Value of radioimmunoscintigraphy with technetium-99m labelled anti-CEA monoclonal antibody (BW431/26) in the detection of colorectal cancer

This study was undertaken as part of a Coordinated Research Programme initiated by the International Atomic Energy Agency to evaluate the usefulness of radioimmunoscintigraphy (RIS) in the management of patients with colorectal cancer. Technetium-99m labelled BW431/26, a monoclonal antibody against carcino-embryonic antigen (CEA), was used. The study included 73 patients (31 females and 42 males). Sixty-eight patients were suspected of having recurrent colorectal adenocarcinoma while another five were suspected to have primary colorectal cancer. Images were acquired at 10 min and 4 and 24 h following the injection of radioantibody. The efficacy of RIS in tumour detection was evaluated by the findings at surgery, histological investigation and/or other diagnostic modalities and clinical follow-up. Four of five patients with suspected primary colorectal cancer gave true-positive results (three at primary sites, one at the site of a metastatic lesion) while one was false-positive. The overall accuracy of RIS in the diagnosis of recurrent colorectal cancer was 87%. Its sensitivity in the detection of locoregional or abdominal recurrence and liver metastases was 97% and 89% respectively. RIS was more accurate than computed tomography (CT) scan in the detection of pelvic recurrence and liver metastases while CT scan was far superior to RIS in detecting lung metastases. RIS proved most useful in patents who had rising CEA levels on clinical follow-up but in whom other work-up, including CT scan, was negative. The advantages of RIS include the ability to detect tumour recurrence prior to other investigations and to identify tumour recurrence in areas such as the pelvis, where CT and magnetic resonance imaging have their greatest weaknesses in diagnosing recurrent disease. The imaging accuracy is significantly increased when combined CT and antibody imaging is performed.     

CT findings after hepatic chemoembolization.

Hepatic arterial chemoembolization (CE) with a mixture of particulate collagen and chemotherapeutic agents was evaluated as therapy for hepatic metastases from colorectal carcinoma. This article describes the characteristics sequential pattern of change seen on liver CT scans following CE. Thirty CT scans were performed on seven patients who had undergone a total of 11 CE procedures. All patients had baseline, immediate postprocedural, and follow-up CT exams at 1 to 2 month intervals following CE. Immediate post-procedural CT scans mapped the area of embolization owing to the density of the contrast mixed with the CE agents. Some lesions seen easily on baseline were more difficult to see as they became isodense with normal liver. Reflux of embolic material into the cystic artery and gallbladder wall was also observed on postprocedural scans in three patients. In all patients, early follow-up scans (1 month after CE) demonstrated changes in lesions seen on baseline scans consistent with tumor necrosis. This was corroborated by a decrease in carcinoembryonic antigen (CEA) levels. In three patients, however, low attenuation regions developed in areas in which there had been no lesion before. The significance of these is uncertain, but the low CEA values and the subsequent evolution in appearance of these sites on CT suggest that they were regions of hepatic ischemia/infarction as opposed to heretofore unidentifiable metastases, now "unmasked." Intermediate follow-up scans (2-3 months) revealed maximal effect on tumor volume, with a decrease of > or = 25% in five of seven patients (71%). Late follow-up scans (> or = 3 months after the last CE) confirmed recurrent disease and new lesions in all cases.     

Ultrasonography of gastrointestinal tract disorders: retrospective and prospective evaluation

In a retrospective analysis performed on 4167 routine abdominal sonographic (US) examinations (September 1989 to December 1991), 93 US reports strongly suggesting the presence of gastrointestinal (GI) tract disorders were found. Neoplastic GI tract diseases were indicated in 65.6 % of cases and non-neoplastic conditions in 34.4 %. The final diagnoses confirmed all the cases of non-neoplastic disease, while 3 patients sonographically suspected as having a neoplasm proved not to have any GI tract abnormality. In the period January 1992 to December 1992, 62 patients with a suspected GI tract abnormality were enrolled in a prospective double-masked US study after being submitted to conventional radiological studies only in 28 of 62 cases, after conventional studies and CT in 24 of 62 cases, and after CT only in 10 of 62 cases. Sonography furnished additional diagnostic information in 28 of 62 cases when the previous radiological examination did not include CT, but sonography misinterpreted 4 inflammatory disorders as tumours. Our study confirmed the important role of US alone or in association with other imaging modalities in the study of GI tract diseases. Correspondence to: S. Mazzeo     

小肠肿瘤的影像学诊断

目的探讨小肠肿瘤的影像学表现及其病理学基础。方法搜集经手术病理证实的小肠肿瘤患者17例进行回顾分析。17例均行全消化道造影和螺旋CT平扫和双期增强扫描,7例行内镜检查。结果低分化腺癌3例,鳞腺癌1例,恶性间质瘤13例。发生于十二指肠7例,空肠6例,回肠4例。钡餐造影主要表现为黏膜变平或破坏12例,管腔狭窄5例。CT表现为不规则肿块,瘤体较大,瘤体内有低密度坏死区和细小钙化灶,双期增强扫描,肿块均有明显的不均匀强化,周围组织和淋巴结受侵。结论对临床疑为原发性小肠肿瘤者应首选上消化道造影,CT是明确诊断的主要影像检查技术,并对指导临床治疗和估计预后有一定的价值。     

A combination of small bowel imaging methods: conventional enteroclysis with complementary magnetic resonance enteroclysis

AIM: The aim of this prospective study was to evaluate the overall findings of conventional enteroclysis (CE) with complementary magnetic resonance enteroclysis (MRE) in small bowel disease. METHODS: The study included 32 patients referred from various clinical departments, with known or suspected small bowel disease and abnormalities on CE. Immediately after CE, true fast imaging with steady-state precession (true FISP), and unenhanced and gadolinium-enhanced T1-weighted fast low-angle shot (FLASH) sequences with fat saturation were obtained. Mucosal, mural and luminal changes of the small bowel were evaluated by each technique. In addition, bowel wall thickening, bowel wall enhancement and perienteric changes were assessed by MRE. The radiological findings obtained were evaluated together as a combination, and the role of MRE in the determination of the activity and complications of the small bowel disease was assessed. Radiological findings were correlated with clinical evaluation and follow-up in all cases, including endoscopy in 14 cases and surgery in 5 cases. RESULTS: MRE provided important supplementary mural and extramural information, including degree of pathological wall thickness, mural enhancement pattern associated with disease activity, perivisceral collection, abscess formation, mesenteric fibrofatty proliferation, lymphadenopathy and increase in perienteric vascularity. Short strictures were not revealed on MRE; however, for patients with a history of abdominal malignancy, MRE helped characterize the level of any obstruction and the extent of the disease. CONCLUSION: We recommend MRE for patients who have findings of advanced inflammatory bowel disease or neoplasm on CE examination. The combination of these two techniques can provide important information on the degree and extent of the disorder.     

“Air bubble”: a new diagnostic CT sign of perforated pulmonary hydatid cyst

The greatest difficulty in the CT diagnosis of perforated pulmonary hydatid cyst (PPHC) is the increase in the attenuation numbers following infection. Because of the solid density of infected hydatid cysts, the differentiation from an abscess or neoplasm is usually impossible. The aim of this study was to evaluate the value of “air bubble” as a new CT sign in the diagnosis of PPHC. Sixty-five patients (28 men and 37 women) with PPHC were included in the study. As a control group, 55 patients who had malignant (n = 36) or non-malignant (n = 19) pulmonary diseases were also examined. Radiological diagnosis with classical CT findings was made in only 38 of 65 patients (58.5 %) with PPHC. Air bubble sign was positive in 54 of the patients with PPHC (sensitivity 83.1 %) but only 3 of 55 patients in control group (specificity 94.5 %). When we analyzed the CT scans with classical CT findings including air bubble, the diagnosis of PPHC was made in 61 of patients (93.8 %). It is concluded that “air bubble sign” is a valuable CT finding in the diagnosis of PPHC. Received: 3 September 1997; Revision received: 22 May 1998; Accepted: 5 August 1998     

Computed tomography in the diagnosis of adrenal disease.

A series of 63 patients with suspected adrenal disease was evaluated by computed tomography (CT). In 15 additional patients CT diagnosed unsuspected adrenal disease. The CT results were correlated with surgical, postmortem, or compelling clinical data. In those patients with adequate visualization of both adrenals, CT correctly identified all adrenal masses subsequently proven at surgery or postmortem examination. CT accurately predicted the presence or absence of a unilateral adrenal neoplasm in patients with Cushing's syndrome and primary aldosteronism. Unsuspected primary or metastatic neoplasms of the adrenals were occasionally detected in patients scanned for other reasons. CT is a safe and accurate method of evaluating patients with suspected adrenal disease.     

PET-CT显像在结肠直肠癌术后复查的临床应用

目的:评价18F-脱氧葡萄糖(FDG)PET-CT显像与CT扫描在诊断结肠直肠癌术后转移与否的准确性。方法:20例临床可疑(血清癌胚抗原(CEA)升高或CT显像阳性或可疑)结肠直肠癌术后转移的患者行全身18F-FDG PET-CT显像,PET-CT显像结果与CT扫描结果对比分析。结果:20例患者共有病灶27个,病理组织学结果及临床随访结果证实,20个恶性病灶,7个良性病灶。PET-CT显像的阳性预测值为94.7%,阴性预测值为75%,CT扫描结果的阳性预测值为81.3%,阴性预测值为36.3%,两者有显著性差异。结论:全身18F-FDG PET-CT显像在诊断结肠直肠癌术后转移与否的准确性高于比CT扫描结果。     

18F-FDG PET/CT全身显像在原发灶不明转移癌中的临床应用

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT全身显像在原发灶不明转移癌(CUP)诊断中的临床应用价值.方法 回顾性分析2006年1月至2007年6月2589例18F-FDG PET/CT显像患者中169例CUP患者的显像结果,通过分析病历记录、病理检查结果及临床随访确定最终原发灶诊断结果.结果 169例CUP患者中19例失访,150例有完整资料.70例成功探测到原发灶,总检出率为46.7%(70/150),其中52例得到病理检查证实,18例为临床诊断;肺癌38例,占54.3%,鼻咽癌8例,占11.4%,消化系统肿瘤13例,占18.6%,其他肿瘤11例,占15.7%.3例临床怀疑转移瘤,18F-FDG PET/CT未见明显恶性征象,经随访证实为良性病变.6例PET/CT诊断错误.15例患者没有确诊.56例未探测到原发灶,其中3例在随访过程中得到确诊,分别为鼻咽癌、膀胱癌、食管癌各1例.结论 18F-FDG PET/CT全身显像对诊断CUP具有重要临床价值.     

Spiral CT colonography in inflammatory bowel disease

OBJECTIVE: Most of the studies on virtual colonoscopy are dealing with the role of detecting colorectal polyps or neoplasms. We have undertaken this study to evaluate the value of CT colonography in patients with colonic Crohn's disease. METHODS AND MATERIAL: Five patients (three males, two females, 23-51 years, mean age 42 years) with known (4) or suspected (1) Crohn's disease of the colon underwent fiberoptic colonoscopy and CT colonography in the same day or during a 1-week period. The images were evaluated with the so called zoomed axial slice movie technique and in some regions intra- and extraluminal surface shaded and volume rendered images were generated on a separate workstation. The results were compared to those of a colonoscopy. RESULTS: The final diagnosis was Crohn's disease in four patients and colitis ulcerosa in one. Total examination was possible by colonoscopy in two cases, and with CT colonography in all five cases. The wall of those segments severely affected by the disease were depicted by the axial CT scans to be thickened. The thick walled, segments with narrow lumen seen on CT colonography corresponded to the regions where colonoscopy was failed to pass. Air filled sinus tracts, thickening of the wall of the terminal ileum, loss of haustration pseudopolyps and deep ulcers were seen in CT colonography. Three dimensional (3D) endoluminal views demonstrated pseudopolyps similar to endoscopic images None of the colonoscopically reported shallow ulcerations or aphtoid ulcerations or granular mucosal surface were observed on 2- or 3D CT colonographic images. CONCLUSION: CT colonography by depicting colonic wall thickening seems to be a useful tool in the diagnosis of Crohn's colitis, which could be a single examination depicting the intraluminal, and transmural extent of the disease.     

16排螺旋CT在卵巢肿瘤中的诊断价值

目的：探讨16排螺旋CT对卵巢肿瘤的诊断价值,为临床诊断鉴别提供参考。方法回顾性分析经手术病理证实的21例卵巢肿瘤的CT影像学特点。结果根据卵巢病变的CT表现,对12例良性卵巢肿瘤及8例恶性肿瘤做出了准确诊断,1例恶性肿瘤误诊。结论16排螺旋CT扫描检查对卵巢肿瘤的定位,定性诊断具有重要价值。     

Diagnosis of colorectal hepatic metastases: comparison of contrast-enhanced CT, contrast-enhanced US, superparamagnetic iron oxide-enhanced MRI, and gadoxetic acid-enhanced MRI

Purpose:

To compare the diagnostic accuracy of contrast‐enhanced computed tomography (CE‐CT), contrast‐enhanced ultrasonography (CE‐US), superparamagnetic iron oxide‐enhanced magnetic resonance imaging (SPIO‐MRI), and gadoxetic acid‐enhanced MRI (Gd‐EOB‐MRI) in the evaluation of colorectal hepatic metastases.

Materials and Methods:

In all, 111 patients with colorectal cancers were enrolled in this study. Of the 112 metastases identified in 46 patients, 31 in 18 patients were confirmed histologically and the remaining 81 in 28 patients were confirmed by follow‐up imaging. CE‐CT, CE‐US, SPIO‐MRI, and Gd‐EOB‐MRI were evaluated. Mean (of three readers, except for CE‐US) area under the receiver operating characteristic curve (A_z), sensitivities, and positive predictive values (PPV) were calculated. Each value was compared to the others by variance z‐test or chi‐square test with Bonferroni correction.

Results:

For all lesions, mean A_z and sensitivity of Gd‐EOB‐MRI (0.992, 95% [56/59]) were significantly greater than those of CE‐CT (0.847, 63% [71/112]) and CE‐US (0.844, 73% [77/106]). For lesions ≤1 cm, mean A_z and sensitivity of Gd‐EOB‐MRI (0.999, 92% [22/24]) were significantly greater than those of CE‐CT (0.685, 26% [13/50]) and CE‐US (0.7, 41% [18/44]). Mean A_z (95% CI) of SPIO‐MRI for all lesions (0.966 [0.929–0.987]) and lesions ≤ 1 cm (0.961 [0.911–0.988]) were significantly greater than those of CE‐CT and CE‐US. Mean sensitivity of SPIO‐MRI for lesions ≤1 cm (63%, 26/41) was significantly greater than that of CE‐CT.

Conclusion:

Gd‐EOB‐MRI and SPIO‐MRI were more accurate than CE‐CT and CE‐US for evaluation of liver metastasis in patients with colorectal carcinoma. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.     

Computed tomography in the evaluation of diverticulitis

Computed tomography (CT) was performed in 43 cases of colonic diverticulitis and compared with the contrast-enema examination (CE) in 37 patients. Findings on CT included inflammation of the pericolic fat in 98% of cases, diverticula in 84%, thickening of the colon wall in 70%, a pericolic abscess in 35%, peritonitis in 16%, a fistula in 14%, colon obstruction in 12%, and intramural sinus tracts in 9%. Secondary findings included a distant abscess in 12% and ureteral obstruction in 7%. In addition to detecting ureteral and bladder involvement and distant abscess formation, CT was preferable for demonstrating the extent of pericolic inflammation, which was underestimated with CE in 41% of patients. Differential diagnosis of the CT findings is discussed. The authors indicate that CT should be the initial procedure in patients with suspected diverticulitis, particularly when CE is contraindicated.     

Colonic diverticulitis: impact of imaging on surgical management – a prospective study of 542 patients

The aim of this study was to compare the performance of the CT and the water-soluble contrast enema (CE) in the diagnosis and the severity of acute left-colonic diverticulitis, and to recognize the impact of CT during the acute phase and after a first acute episode successfully treated medically. From 1986 to 1997, all patients admitted in our emergency center with clinically suspected left-colonic diverticulitis had a CE and a CT within 72 h of their admission, unless clinical findings required immediate laparotomy. They were prospectively included in the study if one or both radiological exams showed signs of acute diverticulitis and/or diverticulitis was surgically removed and histologically proven. Diverticulitis was considered moderate when CT showed localized thickening of the colonic wall (5 mm or more) and inflammation of pericolic fat and CE showed segmental lumen narrowing and tethered mucosa; it was considered severe when abscess and/or extraluminal air and/or contrast were observed on CT and when one or both of the latter signs were seen on CE. Five hundred forty-two patients entered the study; 465 patients (86%) had a CT exam, 439 (81%) had a CE, and 420 (77%) had both exams. The performance of CT is significantly superior to CE in terms of sensitivity (98 vs 92%, p<0.01), and in the evaluation of the severity of the inflammation (26 vs 9%, p<0.02). Moreover, of 69 patients who had an associated abscess seen on CT, only 20 (29%) had indirect signs of this complication on CE. During the acute phase the chances of medical treatment failure are statistically greater when diverticulitis is considered severe on CT than when it is considered moderate (26% for the severe diverticulitis vs 4% for the moderate ones, p<0.0001). After successful medical treatment of the acute episode, patients with severe diverticulitis on the CT had statistically greater incidence of secondary bad outcome than patients with moderate diverticulitis (36 vs 17%, p<0.0001). Computed tomography should be preferred to CE as the initial radiological exam of diverticulitis because of its statistically significant superiority in sensitivity and for its statistically much higher performance in the detection of severe infection, especially when an abscess is associated with the disease. The severity of diverticulitis on CT is statistically predictive of the risk of medical treatment failure during the acute phase and of the chances of bad secondary outcome after a successful medical treatment of the first episode.     

原发性腹膜后肿瘤的CT诊断

目的探讨原发性腹膜后肿瘤的CT诊断与鉴别诊断。方法回顾分析23例经病理证实的原发性腹膜后肿瘤CT资料。结果23例原发性腹膜后肿瘤,有11种病理结果。间叶组织来源的14例,12例为恶性;神经组织起源的4例,均为良性;残余胚胎组织起源的4例,3例为良性,1例为恶性;来源不明的1例为恶性。大部分具有此部位肿瘤共同的CT征象,但又各具有一定特征。结论原发性腹膜后肿瘤种类繁多,观察肿瘤的CT征象,同时结合病人的病史、年龄、部位有助于正确的组织学分类诊断,从而提高对其的定性诊断。