Duodenal neoplasms: predictive value of CT for determining malignancy and tumor resectability.

CT examinations of 25 patients with proved primary or metastatic duodenal neoplasms were retrospectively reviewed to determine if morphologic features seen on CT scans could be used to predict the benign or malignant nature of these neoplasms and to assess the effectiveness of using CT findings to predict tumor resectability. We studied 19 malignant and six benign tumors. Histologic proof was obtained by means of surgery in 20 patients and by endoscopic biopsy in five. CT features of tumor morphology were assessed in the 22 cases in which a duodenal tumor was seen on CT. These features included central necrosis, ulceration or excavation, and the location of the tumor with respect to the bowel wall. The specific morphologic features used to predict that a tumor was malignant included the presence of an exophytic or intramural mass, central necrosis, and ulceration. The only criterion used to predict that a tumor was benign was that the mass be entirely intraluminal. Whenever vascular encasement, invasion of contiguous organs other than the head of the pancreas, distant lymphadenopathy, or metastases were present, the tumor was predicted to be unresectable for cure. With the exception of three benign smooth muscle tumors, all tumors with one or more CT morphologic features indicative of a malignant neoplasm were malignant (n = 16). Three of four intraluminal masses were benign. In three cases of polypoid tumors smaller than 2 cm, a duodenal tumor was not seen on CT. Whenever extraduodenal disease was found (15 cases), the neoplasms were malignant. In the 22 cases in which a tumor was detected on CT, the sensitivity of using the presence of one or more morphologic features associated with a malignant neoplasm as a predictor was 94%; the specificity was 50%, and the accuracy was 82%. If the presence of any morphologic feature indicative of a malignant neoplasm was combined with the presence of any finding of extraduodenal disease, CT was 100% sensitive and 86% accurate for predicting that the tumor was malignant. CT appears to be reliable for predicting duodenal tumor resectability. On the basis of CT findings, 10 tumors were correctly predicted as being unresectable for cure, and 12 were predicted as being resectable; no surgery was performed in the remaining three cases. In conclusion, evaluation of the morphologic features of duodenal neoplasms is a sensitive, but nonspecific, method for predicting that a tumor is malignant.(ABSTRACT TRUNCATED AT 400 WORDS)     

Colorectal neoplasms: role of intravenous contrast-enhanced CT colonography

PURPOSE: To evaluate whether computed tomographic (CT) colonography with intravenously administered contrast material can help predict malignant differentiation of colorectal neoplasms (> or =10 mm in diameter). MATERIALS AND METHODS: Enhancement of 29 consecutive colorectal neoplasms on pre- and postcontrast CT colonographic images was retrospectively measured. The neoplasms were subsequently resected. Enhancement was calculated by subtraction of attenuation values (in Hounsfield units) obtained with precontrast and postcontrast 45-second-delay prone CT colonographic sequences. The neoplasms were graded as follows: grade 1, adenoma; grade 2, adenoma with high-grade dysplasia; grade 3, well-differentiated adenocarcinoma; grade 4, moderately differentiated adenocarcinoma; and grade 5, poorly differentiated adenocarcinoma. Correlation among size, histologic grade, and degree of enhancement was made with Pearson and Spearman coefficients. The ability of the degree of enhancement to help predict adenocarcinoma (histologic grade, > or =3) was calculated. RESULTS: Histologic-CT colonographic correlation was performed in 29 neoplasms (mean diameter, 27.9 mm; range, 10-65 mm). There was no correlation between size and degree of enhancement, size and histologic grade (R = -0.17, P =.33), or histologic grade and degree of enhancement (R = 0.23, P =.23). However, increasing enhancement was noted between grades 2 and 5. When an enhancement threshold of 40 HU was used for the diagnosis of adenocarcinoma (grades 3-5), sensitivity was 92%, specificity was 20%, positive predictive value was 50%, and negative predictive value was 75%. CONCLUSION: The degree of contrast enhancement on a 45-second-delay CT colonographic image does not correlate with size or degree of histologic differentiation, although increasing enhancement with lesser degrees of differentiation was noted.     

Duodenal diverticula mimicking cystic neoplasms of the pancreas: CT and MR imaging findings in seven patients

OBJECTIVE: Duodenal diverticula are common and are typically asymptomatic. When filled with gas or a combination of fluid and gas, duodenal diverticula are easily recognized on CT or MR imaging. However, a duodenal diverticulum that is entirely filled with fluid may mimic a cystic neoplasm arising from the head of the pancreas. We present seven cases of patients with duodenal diverticula in whom initial findings on CT or MR imaging were suggestive of a cystic neoplasm in the head of the pancreas. In all patients, this structure was ultimately proven to be a duodenal diverticula. CONCLUSION: When filled with only fluid, a duodenal diverticulum may mimic a cystic neoplasm in the head of the pancreas. Recognizing the location in which this entity characteristically arises and identifying small amounts of intradiverticular gas when it is present may aid in establishing the correct diagnosis in patients with duodenal diverticula.     

Duodenal diverticulitis: CT and MR findings

We report a case of duodenal diverticulitis and describe the helical computed tomography and contrast-enhanced magnetic resonance imaging (MRI) study findings. Due to its uncommon appearance, this lesion is not typically included in the differential diagnosis of pancreatitis or cholecystitis. The imaging findings of duodenal diverticulitis can be very suggestive of its diagnosis or can narrow the differential diagnosis. To our knowledge and in spite of the wide use of MRI, the contrast-enhanced MRI features of this entity, as described below, have not yet been reported in the literature.     

Duodenal hemangiopericytoma: CT and MRI findings

Hemangiopericytoma (HPC) is a rare mesenchymal tumor generally occurring in adults and originating from the pericytes. The tumor more commonly affects the soft tissues of the extremities, the pelvis, and the retroperitoneum. We describe the computed tomographic and magnetic resonance appearance of a patient affected by HPC of the duodenum.     

CT of esophageal neoplasms

Considerable controversy surrounds the use of computed tomography (CT) in the staging of esophageal carcinoma. New evidence suggests that CT is extremely useful in the selection of patients who may benefit from surgery and/or adjuvant therapy. Additionally, CT can also plan the most efficacious surgical approach. The principles and problems of staging esophageal carcinoma are discussed and useful criteria are presented.     

CT of soft-tissue neoplasms

The computed tomographic scans (CT) of 84 patients with untreated soft-tissue neoplasms were studied, 75 with primary and nine with secondary lesions. Each scan was evaluated using several criteria: homogeneity and density, presence and type of calcification, presence of bony destruction, involvement of multiple muscle groups, definition of adjacent fat, border definition, and vessel or nerve involvement. CT demonstrated the lesion in all 84 patients and showed excellent anatomic detail in 64 of the 75 patients with primary neoplasms. CT did not differentiate vessel or nerve entrapment from neurovascular structures that were simply applied to the pseudocapsule of the tumor. Blurring of adjacent fat was an infrequent finding, but when it was present, the tumor was malignant. The CT findings were characteristic enough to suggest the histology of the neoplasm in only 13 lesions (nine lipomas, three hemangiomas, one neurofibroma). No malignant neoplasm had CT characteristics specific enough to differentiate it from any other malignant tumor. However, malignant neoplasms could be differentiated from benign neoplasms in 88% of the cases.     

十二指肠恶性肿瘤的CT诊断与鉴别诊断

目的　探讨十二指肠恶性肿瘤的CT诊断与鉴别诊断。方法　回顾性分析 2 0例手术病理证实的十二指肠恶性肿瘤的CT平扫和增强资料。结果　原发十二指肠恶性肿瘤 8例 ,其中十二指肠腺癌 3例 ,恶性淋巴瘤 2例 ,恶性间质瘤 3例 ;十二指肠继发性恶性肿瘤 12例 ,其中壶腹癌 3例 ,胰头癌 8例 ,胰腺无功能性神经内分泌癌 1例。十二指肠腺癌CT表现为肠腔局限性不规则环状狭窄伴软组织肿块 ,增强扫描肿块有中度强化 ;恶性淋巴瘤的特点是长范围的肠壁增厚或肠腔外肿块 ,增强扫描肿块有轻度强化 ;恶性间质瘤的特点是巨大软组织肿块伴明显、不均匀强化 ,肠梗阻不明显。壶腹癌表现为十二指肠降部内侧壁的局限性肿块 ,增强有轻中度强化 ,伴肝内外胆管扩张 ;胰头癌累及十二指肠表现为十二指肠内侧壁凹凸不平 ,邻近的胰头部肿块 ,增强扫描不强化 ,伴肝内外胆管扩张 ;胰腺无功能性神经内分泌癌侵及十二指肠表现为胰头部巨大肿块伴明显强化 ,肝内外胆管不扩张 ,肿块与十二指肠分界不清。结论　CT检查对十二指肠恶性肿瘤有重要的诊断和鉴别诊断价值。     

十二指肠壅积症的CT影像分析

目的 探讨十二指肠壅积症(DSD)的多层螺旋CT影像表现及诊断价值.方法 对17例DSD患者(实验组)及20例无症状的成年人(对照组)进行仰卧位多层螺旋CT检查,分析两组人群十二指肠和肠系膜上动脉(SMA)的CT影像表现,比较两组的影像差异.结果 DSD的CT影像包括胃十二指肠球部、降段及部分水平段扩张,SMA对十二指肠水平段造成压迹,十二指肠水平段充盈不佳、管腔狭窄等改变;实验组SMA与腹主动脉(A0)的夹角与对照组相近,两组间无显著差异(t=0.713,P＞0.20);实验组SMA与AO间距较对照组小,但两组间无显著差异(t =0.545,P＞0.25).实验组SMA与AO间距＜10 mm者有10例(58.82％)、SMA与AO夹角＜30°者有11例(64.71％),而对照组SMA与AO间距＜10 mm者7例(35％)、SMA与AO夹角＜30°者4例(20％),但两组之间SMA与AO间距及夹角的差异均不具有统计学意义(精确概率P=0.068,0.071).实验组中11例SMA与AO夹角＜30°的患者,这11例患者与实验组之间SMA与AO夹角的差异也不具有统计学意义(t=0.768,P＞0.10).结论 多层螺旋CT观察十二指肠的形态变化有利于DSD的诊断,但单纯测量SMA与AO间距和夹角是否能确诊DSD则难以定论.     

Cystic neoplasms of the pancreas: CT and sonography

Cystic neoplasms of the pancreas are pathologically divided into macrocystic adenomas and microcystic adenomas, the former are considered a premalignant lesion and the latter without malignant potential. Five cases of cystic neoplasms are presented and the sonographic and/or computed tomographic features of microcystic and macrocystic adenoma are compared. A specific diagnosis can at times be suggested based on the computed tomography and sonography findings. In the proper clinical setting microcystic adenoma should be considered in the differential diagnosis of a pancreatic mass seen on sonography and computed tomography. Preoperative biopsy with appropriate pathologic staining can be performed and aid in directing appropriate therapy.     

Multidetector CT in small-bowel neoplasms

PURPOSE: The aim of this study was to assess the diagnostic potential of multidetector computed tomography (MDCT) in the evaluation of small-bowel neoplasms. MATERIALS AND METHODS: We studied 120 patients with suspected small-bowel disease by 16-slice MDCT after oral administration of a polyethylene glycol solution (n=56) or methylcellulose via a nasojejunal tube (n=64). Unenhanced and contrast-enhanced CT was performed. Contrast-enhanced CT images were acquired 40 s after IV injection of 130 ml of iodinated contrast agent at a rate of 3 ml/s. Multiplanar reconstructions were performed at the end of the examinations. RESULTS: Fifteen patients were found to be affected by small-bowel neoplasm (six had non-Hodgkin's lymphoma, three had carcinoid tumour, two had Peutz-Jeghers syndrome, two had adenocarcinoma, two had melanoma metastases, one had lipoma). In the remaining patients, 58 cases of Crohn's disease and seven miscellaneous diseases were detected. All findings were confirmed by barium studies, surgery or endoscopy. CONCLUSIONS: MDCT performed after bowel-loop distension with low-density contrast material and IV administration of iodinated contrast agent is a reliable method for diagnosing and staging small-bowel neoplasms.     

螺旋CT诊断十二指肠溃疡230例

 目的 探讨螺旋CT诊断十二指肠溃疡的价值.方法 回顾性研究230例上腹部CT检查患者的图像资料,收集怀疑为十二指肠溃疡患者的病例,追踪胃镜/胃肠造影结果,记录确诊为十二指肠溃疡的CT表现.结果 CT可疑十二指肠溃疡17例,经胃镜和胃肠造影明确诊断10例,CT诊断准确率为66.7%.十二指肠溃疡常见表现为肠壁增厚、管腔狭窄和球变形等.结论 CT诊断十二指肠溃疡有一定价值,对指导临床选择恰当的检查方法和治疗方案有重要意义.     

原发性阑尾肿瘤的CT诊断

目的评价原发性阑尾肿瘤的CT表现.方法对24例经手术和病理证实的原发性阑尾肿瘤病人的腹部CT进行回顾性分析,记录阑尾直径、阑尾壁厚度、阑尾腔内改变及阑尾浆膜面改变等,并注意盲肠、末段回肠、阑尾周围脂肪改变和腹腔淋巴结肿大等.结果24例原发性阑尾肿瘤为黏液性腺瘤(n=11)、黏液性腺癌(n=5)、结肠型腺癌(n=4)和类癌(n=4).阑尾最大直径为12 mm～52 mm,19例(79%)最大直径超过15 mm;阑尾壁最大厚度3 mm～16 mm,13例(58%)在5 mm以上;10例(42%)可见阑尾腔内肿块阑尾内壁不规则隆起,1例(4%)可见阑尾表面外突性肿块.使用阑尾肿块/囊状扩张/直径大于15 mm的综合标准诊断率为92%.如附加阑尾壁厚度大于5 mm的标准则诊断率为100%.结论CT是发现阑尾肿瘤的有效方法,表现为阑尾肿块、阑尾腔囊状扩张、直径大于15 mm和壁厚超过5 mm.     

阑尾原发肿瘤的CT诊断

目的评价阑尾原发肿瘤的CT表现。方法对27例经手术病理证实的阑尾原发肿瘤患者的腹盆部CT进行回顾性分析:记录肿物大小、肿物形态(肿物长短径比例大于1.5者为长管状)、肿物密度(肿物密度分为囊性、实性),囊性肿物囊壁厚度、囊壁有无钙化、肿物浆膜面表现,周围脂肪间隙改变,有无淋巴结转移及远处器官转移。结果 27例阑尾原发肿瘤,其中黏液性囊腺瘤11例、交界恶性囊腺瘤3例,黏液性囊腺癌10例、腺癌3例,良性者多表现为囊性肿物,恶性者伴囊壁增厚、强化,腹水、腹腔假黏液瘤的比例增加。结论 CT是发现阑尾原发肿瘤的有效检查方法,多表现为阑尾囊性肿物,可伴发腹腔假黏液瘤,术前CT检查对正确诊断有帮助。     

Imaging of pancreatic neoplasms: comparison of MR and CT

Thirty-two patients with pathologically proved pancreatic carcinomas or cystadenomas were evaluated with MR images obtained with T1-weighted spin echo (short TR/short TE), inversion recovery, and T2-weighted spin-echo (long TR/long TE) pulse sequences. CT was used as the reference standard to determine the ability of MR to delineate normal and abnormal pancreatic anatomy and thereby to exclude or detect pancreatic malignancy. Short TR/short TE spin-echo sequences were significantly better (p less than .05) than inversion recovery or T2-weighted spin-echo sequences in resolution of both normal and abnormal anatomy. Resolution of pancreatic anatomy correlated (r = .9) with the image signal-to-noise ratio. In seven (22%) of 32 cases, MR visualized pancreatic tumors better than CT did because it showed a signal intensity difference between the tumor and normal pancreatic tissue. Overall, the slight superiority of MR over CT for tumor visualization tended to occur in larger tumors and was not statistically significant. On T1-weighted images, 63% (20 of 32) of pancreatic tumors studied had lower signal intensities than normal pancreatic tissue, whereas on T2-weighted sequences (TE = 60, 120, and 180 msec) only 41% (13 of 32) of tumors had increased signal intensities. Currently available MR imaging techniques offer no significant advantages over CT for evaluating the pancreas for neoplasia.     

Helical CT with CT angiography in assessing periampullary neoplasms: identification of vascular invasion

PURPOSE: To determine the accuracy of helical computed tomography (CT) with CT angiography in identifying vascular invasion by periampullary neoplasms and to assess the added value of CT angiography. MATERIALS AND METHODS: Sixty-nine patients suspected of having periampullary neoplasms were examined. Images from dual phase helical CT with CT angiography were compared with surgical findings in 36 patients. Arterial and venous invasion were assessed separately. Accuracy, positive predictive value (PPV), and negative predictive value (NPV) were determined for CT alone and for CT supplemented with CT angiography. RESULTS: The accuracy, PPV, and NPV of helical CT with CT angiography in identifying venous invasion was 92% (33 of 36 patients), 86% (12 of 14 patients), and 95% (21 of 22 patients), respectively. When transverse CT images alone were analyzed, accuracy decreased to 69% (25 of 36 patients) (P =.005); PPV and NPV were 63% (five of eight patients) and 71% (20 of 28 patients), respectively. When identifying arterial invasion, the accuracy of CT with CT angiography and of CT alone was 86% (31 of 36 patients). PPV and NPV also were identical at 71% (five of seven patients) and 90% (26 of 29 patients), respectively. CONCLUSION: CT angiography significantly increases the ability to identify venous invasion when compared with CT alone but does not improve detection of arterial invasion.     

CT of pancreatic neoplasms Part II: The unusual tumors

The pancreas gives rise to a remarkable variety of neoplasms other than ductal adenocarcinoma. Although no individual type of tumor in this category is prevalent enough to qualify as common, most types are currently encountered with a frequency far greater than that in decades of the recent past. This change is largely the result of the expanded use of contemporary abdominal imaging. The unusual tumors of the pancreas vary greatly in their biologic behavior and, accordingly, in their clinical consequences and therapeutic requirements. Accurate diagnosis, therefore, can be of considerable clinical relevance. Not only is it worthwhile to distinguish one type of unusual pancreatic tumors from another, it is perhaps of even greater consequence to distinguish the unusual tumors from ordinary pancreatic adenocarcinomas. The goals of this discussion are to expand radiologic awareness of these uncommon but interesting pancreatic neoplasms and to increase familiarity with their diagnostically salient features.     

CT imaging review of uncommon peritoneal-based neoplasms: beyond carcinomatosis

Pathologic involvement of the peritoneum can result from a wide variety of conditions, including both neoplastic and non-neoplastic entities. Neoplastic involvement of the peritoneal ligaments, mesenteries, and spaces from malignant spread of epithelial cancers, termed peritoneal carcinomatosis, is frequently encountered at CT evaluation. However, a host of other more unusual benign and malignant neoplasms can manifest with peritoneal disease, including both primary and secondary peritoneal processes, many of which can closely mimic peritoneal carcinomatosis at CT. In this review, we discuss a wide array of unusual peritoneal-based neoplasms that can resemble the more common peritoneal carcinomatosis. Beyond reviewing the salient features for each of these entities, particular emphasis is placed on any specific clinical and CT imaging clues that may allow the interpreting radiologist to appropriately narrow the differential diagnosis and, in some cases, make an imaging-specific diagnosis.