The most useful findings for diagnosing acute appendicitis on contrast-enhanced helical CT

PURPOSE: To evaluate the most useful findings to look for in diagnosing acute appendicitis on contrast-enhanced helical CT. MATERIAL AND METHODS: Appendiceal helical CT scans with intravenous contrast administration (abdomen, 7-mm collimation; abdominopelvic junction, 5-mm collimation) of 71 patients with surgically proven acute appendicitis and 167 patients with alternative diagnoses were reviewed retrospectively. Three radiologists analyzed the following parameters: enlarged appendix (>6 mm in diameter), appendiceal wall thickening, appendiceal wall enhancement, no identification of the appendix, appendicolith(s), appendiceal intraluminal air, intramural air, extraluminal air, periappendiceal fat stranding, extraluminal fluid, phlegmon, abscess, lymphadenopathy, segmental terminal ileal wall thickening, focal cecal apical thickening, focal colonic wall thickening, and segmental colonic wall thickening. The features that best distinguished appendicitis from alternative diagnoses were selected with stepwise logistic regression analysis. RESULTS: Nine CT findings distinguished acute appendicitis from alternative diagnoses (P < 0.05): enlarged appendix (R = 0.739), appendiceal wall thickening (R = 0.525), periappendiceal fat stranding (R = 0.414), appendiceal wall enhancement (R = 0.404), focal cecal apical thickening (R = 0.171), appendicolith(s) (R = 0.157), extraluminal air (R = 0.050), intramural air (R = 0.043), and phlegmon (R = 0.030). Enlarged appendix (sensitivity, 93%; specificity, 92%), appendiceal wall thickening (sensitivity, 66%; specificity, 96%), periappendiceal fat stranding (sensitivity, 87%; specificity, 74%), and appendiceal wall enhancement (sensitivity, 75%; specificity, 85%) showed the statistically most significant association with acute appendicitis. CONCLUSION: On 5-mm-section contrast-enhanced helical CT examinations, enlarged appendix, appendiceal wall thickening, periappendiceal fat stranding, and appendiceal wall enhancement were the most useful findings for diagnosing acute appendicitis.     

Differentiating malignant from benign wall thickening in postoperative stomach using helical computed tomography: results of multivariate analysis

OBJECTIVE: To determine significant computed tomography (CT) predictors for differentiating malignant from benign wall thickening in postoperative stomach. METHODS: Sixty-nine patients with perianastomotic wall thickening (25 malignant, 44 benign) after gastric surgery were identified. All patients underwent contrast-enhanced CT with the administration of oral contrast agents such as air, diluted barium, or water. Two radiologists analyzed CT images regarding enhancement of thickened wall, obliteration of wall layering, heterogeneity, asymmetry, perigastric infiltration, proximity to metallic suture material, lymphadenopathy, adjacent bowel thickening, and periceliac soft-tissue density. Another radiologist measured the wall thickness and the mean CT value of the lesion and normal mucosa. Individual CT findings relevant as predictors were determined using the univariate test. Multivariate analysis was used to determine the most predictable factors. RESULTS: Malignant wall thickening was significantly thicker than benign one. Isoattenuation and high attenuation of thickened wall were more frequently seen in malignant than in benign cases. Multivariate analysis showed that isoattenuation or high attenuation of thickened wall, proximity to suture material, and perigastric infiltration were only 3 variables that independently differentiated malignant from benign thickening in postoperative stomach. CONCLUSION: Isoattenuation or high attenuation of thickened wall, perigastric infiltration, and wall thickening without metallic suture material are the 3 main factors distinguishing malignant from benign thickening in postoperative stomach.     

Benign and malignant gastric ulcer: CT findings]

PURPOSE: To evaluate the differential CT aspects of benign and malignant gastric ulcers. MATERIALS AND METHODS: We retrospectively reviewed the CT findings of 54 patients with gastric ulcerative lesions, 47 with malignant lesions (38 adenocarcinomas, 9 lymphomas) and 7 with benign lesions. All patients underwent histological examination. CT scanning was performed with a helical scanner Picker PQ 2000, before and after intravenous contrast material administration and after adequate stomach distension, achieved by drinking at least 400 ml of water; 2 ml/kg of intravenous contrast was injected at a rate of 3.5 ml/s. After contrast administration two-phase dynamic scans were performed with a scan delay of 30O and 50O. The parameters considered were: lesion size and localization, extension of the ulcer into or beyond the body of the stomach, focal wall thickness, contrast enhancement of the ulcer, perigastric tissue morphology, presence of lymphoadenopathies and liver metastases. RESULTS: The ulcer size and localization were not significative in the differential diagnosis of benign or malignant ulcers. In 46 patients the ulcer extended within the body of the stomach (38 adenocarcinomas and 8 lymphomas), in 8 cases beyond (7 benign ulcers and 1 initial lymphoma). In 46 cases of malignant ulcers there were focal wall thickenings (> 5mm), in 1 case of initial lymphoma and in all cases of benign ulcers the thickness of the wall was normal. Contrast enhancement of the lesion was observed in 25 cases, all of which were adenocarcinomas. 33 patients had perigastric tissue abnormalites (32 with malignant lesions and 1 with benign ulcer). Lymphoadenopathies and liver metastases were detected in 30 cases and always associated to malignant ulcers. DISCUSSION AND CONCLUSIONS: The improved CT technology allows to recognize gastric ulcer. Ulcer extension into stomach body; focal wall thickening; contrast enhancement of the lesion, lymphoadenopaties and liver metastases are significative in malignant gastric ulcers. The lack of these abnormalities is characteristic of benign gastric ulcers but can be also observed in early malignant lesions.     

CT of the stomach and duodenum

CT has become an important tool in the diagnosis and management of diseases that affect the stomach and duodenum. By depicting the bowel lumen, wall, and extramural structures, CT can provide unique information that complements standard air contrast radiography and endoscopy. Proper scanning methods and knowledge of normal anatomy are necessary for optimal results. We utilize the gas contrast technique for organ-specific examination in patients with known or suspected gastroduodenal disease. Gastric adenocarcinoma is an important indication for CT evaluation. Unfortunately, early hopes that CT could accurately stage gastric cancer have not been realized. CT is not as accurate as laparotomy in staging early gastric cancer, primarily owing to its inability to detect small peritoneal implants, diagnose metastases in normal-sized lymph perigastric nodes, and predict pancreatic invasion. Nevertheless, CT retains an important role in depicting gross metastatic disease and guiding percutaneous biopsy, particularly in patients who are deemed poor surgical candidates or have undergone prior gastric resection. A variety of conditions other than primary gastric adenocarcinoma produce recognizable abnormalities on CT. Gastric lipoma, leiomyosarcoma, and varices have a distinctive appearance. Others, including gastritis and uncomplicated peptic ulcer, produce nonspecific gastric wall thickening. Endoscopic correlation and biopsy are required for specific diagnosis in these cases. The duodenum, by virtue of its location in the anterior pararenal compartment of the retroperitoneum, may be involved by numerous benign and malignant conditions. In blunt trauma, complicated pancreatitis, and peptic ulcer disease, as well as primary and metastatic malignancy, CT can provide data that may alter patient management.     

Temporal evolution of multidetector CT findings after endoscopic submucosal dissection in patients with early gastric cancer: Correlation with endoscopy

Objective

To assess changes over time in imaging findings retrospectively by multidetector CT (MDCT) with two-dimensional (2D) multiplanar reconstruction and three-dimensional (3D) CT gastrography (CTG), after endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC), and to correlate 3D CT images with endoscopic appearance.

Materials and methods

In this retrospective study, a total of 84 patients underwent ESD and were followed up with MDCT. Fifteen patients underwent CT twice, and 3 patients underwent CT 3 times. A total of 105 CTs were included in this study and 43 CTs contained 3D CTGs. Two radiologists in consensus interpreted CT images for lesion detectability, presence and characteristics of ulcer, focal wall thickening, perigastric fat infiltration, and overlying enhancing layer in 2D images. The presence of ulcer or subtle mucosal nodularity, ulcer mound, and fold convergence were analysed in 3D CT images. We also assessed the time interval between ESD and CT and analysed the temporal evolution of CT findings. The sensitivity, specificity, and overall accuracy of 3D CTG were assessed regarding endoscopic features as the gold standard.

Results

The mean interval between ESD and follow up CT was 76.9 days (median, 62; range, 2–223). No tumour recurrence in any lesion was found on follow-up endoscopic biopsy and also lymph node or distant metastasis was not observed on CT exams in the follow-up period. The lesion detectability in a total of 105 post-ESD 2D CT images was 42.0% (44/105), and 93.2% (41/44) of the detected lesions were visualizable 2 months after ESD. Focal wall thickening was observed during the entire follow-up period in all patients. Perigastric fat infiltration was observed in 4 lesions within 1 week of ESD. Overlying enhancing layer appeared in 27 lesions without temporal evolution. On a total of 43 post-ESD 3D CTG, lesion detectability was 76.7% (33/43), and lesions could be visualized for a longer period than by 2D CT images (223 days versus 99 days). Three-dimensional imaging features revealed ulcer, ulcer mound, and fold convergence. Ulcer mounds disappeared first (median, 12.5 days; range, 2–14 days after ESD), ulcers appeared up to 4 months after ESD (median, 14 days; range, 2–174 days after ESD) and fold convergence continued to the end of the study (median, 74 days; range, 2–223 days after ESD). We found that sensitivity, specificity, and overall accuracy of 3D CTG were 70.0%, 92.9%, 83.3% for ulcer, 28.6%, 100%, 71.4% for ulcer mound, and 71.4%, 100%, 75% for fold convergence regarding endoscopy, respectively.

Conclusion

On follow-up 2D or 3D CT images after ESD, early findings were of perigastric fat infiltration, ulcer, and surrounding oedema. Focal wall thickening and fold convergence continued to be observed late in the study. The overlying enhancing layer did not show temporal evolution.     

Pseudomembranous colitis: spectrum of imaging findings with clinical and pathologic correlation.

Pseudomembranous colitis (PMC) is a potentially life-threatening acute infectious colitis caused by one or more toxins produced by an unopposed proliferation of Clostridium difficile bacteria. PMC is characterized by the presence of elevated, yellow-white plaques forming pseudomembranes on the colonic mucosa. These plaques can be visualized at both pathologic analysis and endoscopy. Plain radiography, contrast enema studies, and computed tomography (CT) are useful in the evaluation of PMC. Plain radiography of the abdomen can demonstrate polypoid mucosal thickening, "thumbprinting" (wide transverse bands associated with haustral fold thickening), or gaseous distention of the colon. A toxic megacolon with distention and occasionally pneumoperitoneum may be seen in the most severe cases of PMC involving perforation. At contrast enema studies, the primary finding in mild cases of PMC is small nodular filling defects representing the mucosal plaques. With more extensive colonic involvement, the plaques are larger and coalesce to form an irregular bowel wall margin. Mural thickening and wide haustral folds caused by intramural edema may also be seen. A contrast enema study is contraindicated in patients with severe PMC due to the danger of perforation. Common CT findings include wall thickening, low-attenuation mural thickening corresponding to mucosal and submucosal edema, the "accordion sign," the "target sign" ("double halo sign"), pericolonic stranding, and ascites. Familiarity with these imaging characteristics may allow early diagnosis and treatment and prevent progression to more serious pathologic conditions.     

Radiologic Findings of Multiple Myeloma with Gastric Involvement: A Case Report

We report a case of multiple myeloma with gastric involvement occurring in a patient who underwent an upper gastrointestinal series (UGIS), CT and MRI. UGIS depicted a luminal protruding mass, while contrast-enhanced CT demonstrated marked thickening of the gastric wall, with subtle contrast enhancement. At T1- and T2-weighted MR imaging, the mass showed iso- and intermediate signal intensity, respectively. After the administration of contrast material, subtle homogeneous enhancement was apparent.     

Depiction of normal gastrointestinal anatomy with MDCT: comparison of low- and high-attenuation oral contrast media

PURPOSE: To compare low- and high-attenuation oral contrast media for depiction of normal gastrointestinal anatomy with multidetector-row computed tomography (MDCT). MATERIALS AND METHODS: A prospective, randomized study of 90 consecutive patients without known or suspected gastrointestinal disease was conducted after the approval of our Institutional Review Board. All patients underwent IV contrast-enhanced abdominal and pelvic CT scans after oral administration of 900 ml of either low- or high-attenuation barium sulphate suspension. Using a five-point scale, two radiologists independently graded distention and wall visualization of stomach, duodenum, jejunum, and ileum. The degree of distention and wall visualization was compared using Mann-Whitney U-test. RESULTS: Duodenal, jejunal and ileal distention (p<0.05, <0.001, <0.001, respectively) and wall visualization (p<0.05, <0.01, <0.05, respectively) scores with low-attenuation contrast medium were significantly higher than those with high-attenuation barium sulphate preparation, for reader 1. Duodenal and jejunal wall visualization scores with low-attenuation contrast medium (p<0.05, <0.01, respectively) were significantly higher than those with high-attenuation contrast medium, for reader 2. Interobserver agreement was fair to good for both distention (kappa-range: 0.41-0.74) and wall visualization (kappa-range: 0.48-0.71). CONCLUSION: MDCT with low-attenuation contrast medium provides distention and wall visualization of the GI tract that is equal or better than high-attenuation contrast medium.     

Current role of CT in imaging of the stomach.

Recent advances in computed tomographic (CT) technology and three-dimensional (3D) imaging software have sparked renewed interest in using CT to evaluate gastric disease. Multidetector row CT scanners allow thinner collimation, which improves the visualization of subtle tumors as well as the quality of the 3D data sets. When water is used as an oral contrast agent, subtle disease is easier to visualize, especially when a rapid contrast material bolus is intravenously administered. Adenocarcinoma is the most common gastric malignancy and typically appears as focal or segmental wall thickening or a discrete mass. Gastric lymphoma can have a CT appearance similar to that of adenocarcinoma. Both gastric adenocarcinoma and lymphoma may be associated with adenopathy. Gastrointestinal stromal tumors (GISTs) tend to appear as well-defined masses that arise from the gastric wall and may be exophytic when large. GISTs are usually not associated with significant adenopathy. In addition to gastric malignancies, CT can also help detect inflammatory conditions of the stomach, including gastritis and peptic ulcer disease. CT angiography is especially helpful for depicting the gastric vasculature, which may be affected by a variety of disease conditions. Copyright RSNA, 2003.     

增强螺旋CT扫描技术在胃癌诊断和分期中的应用

目的 探讨胃癌螺旋CT增强特征及增强扫描技术在胃癌诊断和分期中的作用。方法 对照分析50例胃癌患者的CT增强表现和术后的病理结果。患者CT扫描前30min饮水1000～1500ml，扫描前5～10min肌注山莨菪碱10mg，均行CT平扫和增强扫描。结果 胃癌的CT表现为胃壁局部或弥漫性增厚、软组织块影和固定的狭窄胃腔，部分病例合并癌性溃疡，并侵犯邻近组织，可有邻近或远处淋巴结肿大转移。病灶好发于贲门和胃窦部，增强扫描时病灶较平扫更明显，并有显著强化。CT分期的准确率达86％，淋巴结转移的检测率为60％。结论 螺旋CT增强扫描技术是诊断胃癌和对胃癌进行分期的一种可靠方法，有助于临床更好地治疗胃癌患者。     

CT imaging signs of surgically proven bowel trauma

The objective of this study was to determine the incidence and interobserver agreement of individual CT findings as well as the bowel injury prediction score (BIPS) in surgically proven bowel injury after blunt abdominal trauma. This HIPAA-compliant retrospective study was IRB approved and consent was waived. All patients 14 years or older who sustained surgically proven bowel injury after blunt abdominal trauma between 1/1/2004 and 6/30/2015 were included. Admission trauma MDCT scans were independently interpreted by two abdominal fellowship-trained radiologists who recorded the following CT findings: intraperitoneal fluid, mesenteric hematoma/fat stranding, bowel wall thickening/hematoma, active intravenous contrast extravasation, free intraperitoneal air, bowel wall discontinuity, and focal bowel hypoenhancement. Subsequently, the electronic medical records of the included patients, admission abdominal physical exam results, admission white blood cell count, and findings at exploratory laparotomy of the included patients were recorded. Thirty-three patients met the inclusion criteria. The incidence and interobserver agreement of the CT findings were as follows: intraperitoneal fluid 93.9 %, kappa?=?0.784 (good); mesenteric hematoma/fat stranding 84.8 %, kappa?=?0.718 (good); bowel wall thickening/hematoma 42.4 %, kappa?=?0.491 (moderate); active IV contrast extravasation 36.3 %, kappa?=?1.00 (perfect); free intraperitoneal air 21.2 %, kappa?=?0.904 (very good), bowel wall discontinuity 6.1 %, kappa?=?1.00 (perfect); and focal bowel hypoenhancement 6.1 %, kappa?=?0.468 (moderate). An absence of the specified CT findings was encountered in 9.1 % with surgically proven bowel injuries (kappa?=?1.00, perfect). In our study, 9/16 patients or 56.3 % had a bowel injury prediction score (BIPS) of 2 or more as defined by McNutt et al. (J Trauma Acute Care Surg 78(1):105–111, 2014). The presence of intraperitoneal fluid and mesenteric hematoma/fat stranding are the most common CT findings in bowel injuries proven at laparotomy. A small percentage of patients have no abnormal CT findings. This grading system did not prove to be useful in our study likely due to our inherently small patient population; however, the use of BIPS deserves further investigation as it may help in identifying blunt bowel and mesenteric injury patients with often subtle or nonspecific CT findings.     

获得性免疫缺陷综合征相关消化道病变的影像学表现

目的：初步探讨艾滋病（AIDs）相关消化道病变的影像学表现。方法：回顾性分析11例AIDS相关消化道病变的影像学表现。行胸部平片检查11例,胸部CT扫描4例,腹部CT扫描9例,盆腔CT扫描2例,盆腔MRI检查1例,消化道内窥镜检查9例。结果：11例中消化道穿孔3例（食管穿孔2例,胃穿孔1例）、肠结核2例、巨细胞性肠炎1例、淋巴瘤4例、胃腺癌1例。食管穿孔的主要影像表现为食管一纵隔瘘伴纵隔淋巴结结核及双肺结核;胃穿孔主要表现为胃瘘伴肝左叶及肝胃间隙脓肿;肠结核主要表现为回盲部肠壁增厚;巨细胞性肠炎主要表现为乙状结肠末段及直肠管壁向心性增厚;淋巴瘤主要表现为受累消化道管壁肿块状增厚,肠腔狭窄或扩张,多伴溃疡及病变周围淋巴结增大;胃腺癌主要表现为胃壁增厚、僵硬及明显强化。结论：AIDS相关消化道病变可表现为多种机会性感染和恶性肿瘤,影像学检查对这些病变的诊断具有重要作用。     

64层螺旋CT对胃淋巴瘤和进展期胃癌的鉴别诊断价值

目的探讨64层螺旋CT对胃淋巴瘤和进展期胃癌的鉴别诊断价值。资料与方法回顾性分析经病理证实的21例胃淋巴瘤和46例进展期胃癌患者的CT表现。结果胃淋巴瘤和进展期胃癌累及多部位者分别占61.90%和23.91%,黏膜面出现白线征者分别占0%和76.09%,侵犯范围>50%胃周径分别占76.19%和15.22%,显示溃疡形成者分别占9.52%和73.91%,出现胃腔形态固定、狭窄,近侧胃腔扩大者分别占4.76%和36.96%,显示病灶处胃壁浆膜面光滑,胃周脂肪间隙清晰者分别占80.95%和0%,两组病例比较有显著性差异(P<0.05)。结论64层螺旋CT对鉴别诊断胃淋巴瘤和进展期胃癌有重要的临床价值。     

Differential CT features of infectious pneumonia versus bronchioloalveolar carcinoma (BAC) mimicking pneumonia

The purpose of this study was to evaluate retrospectively the differential CT features of bronchioloalveolar carcinoma (BAC) mimicking pneumonia and infectious pneumonia at the lung periphery. CT images were reviewed in 47 patients with focal areas of parenchymal opacification at the lung periphery. We evaluated the presence of ground-glass attenuation, marginal conspicuity of the lesion, CT angiogram sign, air-bronchogram sign, a bubble-like low-attenuation area within the lesion, presence of pleural thickening and retraction associated with the lesion, presence of pleural effusion and extra-pleural fatty hypertrophy, presence of bronchial wall thickening proximal to the lesion, and air-trapping in the normal lung near the lesion. BAC (n=18) depicted the presence of a bubble-like low-attenuation area within the lesion, whereas infectious pneumonia (n=29) represented the pleural thickening associated with the lesion and bronchial wall thickening proximal to the lesion (P<0.05). The other CT findings showed no significant differences (P>0.05). The focal areas of the parenchymal opacification on the CT images may suggest infectious pneumonia rather than BAC when they show bronchial wall thickening proximal to the lesion and pleural thickening associated with the lesion, whereas BAC is characterized as the presence of a bubble-like low attenuation area within the tumor.     

CT of bowel and mesenteric trauma in children.

Although most traumatic abdominal injuries in children are treated with conservative nonsurgical management, traumatic perforation or infarction of the gastrointestinal tract still necessitates surgical management. It is imperative to recognize the often subtle computed tomographic (CT) findings of bowel or mesenteric trauma in children. Pediatric patients with bowel perforation or infarction due to trauma usually demonstrate multiple abnormalities at CT. A specific history of lap belt injury, bicycle handlebar injury, or child abuse with an abdominal injury should heighten suspicion for a bowel injury. CT findings in children with bowel or mesenteric trauma include free intraperitoneal air, free retroperitoneal air, extraluminal oral contrast material, free intraperitoneal fluid, bowel wall defect, bowel wall thickening, mesenteric stranding, fluid at the mesenteric root, focal hematoma, active hemorrhage, and mesenteric pseudoaneurysm. Some findings, such as free intraperitoneal air and focal bowel wall thickening, are associated with a strong likelihood of a bowel injury that requires surgical repair. Other findings, such as free intraperitoneal fluid, mesenteric stranding, fluid at the mesenteric root, and focal hematoma, are less specific for an injury that requires surgical repair. The hypoperfusion complex can usually be differentiated from a traumatic bowel injury; however, in some patients the imaging findings overlap.     

CT features with pathologic correlation of acute gastrointestinal graft-versus-host disease after bone marrow transplantation in adults

OBJECTIVE: This study was conducted to describe the CT features of acute gastrointestinal graft-versus-host disease in adults and to correlate these findings with the pathologic grades of disease severity. MATERIALS AND METHODS: Patients (n = 22) with a history of allogeneic bone marrow transplantation and pathologically confirmed acute gastrointestinal graft-versus-host disease underwent contrast-enhanced (n = 13) and unenhanced (n = 9) CT. CT scans were retrospectively evaluated for intestinal and extraintestinal abnormalities by two radiologists who were unaware of the biopsy results. The CT findings were correlated with the pathologic grade of disease severity using the Pearson's correlation coefficient and the two-tailed nonparametric Spearman's rank correlation coefficient. RESULTS: CT features included small-bowel wall thickening (22/22), engorgement of the vasa recta adjacent to affected bowel segments (20/22), stranding of the mesenteric fat (16/22), large-bowel wall thickening (13/22), bowel dilatation proximal to thickened wall segments (5/22), ascites (10/22), periportal edema (8/22), mucosal enhancement (7/13), and serosal enhancement (4/13). The wall thickening had a discontinuous distribution in nine patients (41%). Bowel wall thickening was associated with high-grade graft-versus-host disease in patients in whom the distal esophagus (p = 0.015), ileum (p = 0.034), or ascending colon (p = 0.05) was involved. Increasing numbers of thickened bowel segments correlated with high-grade graft-versus-host disease (r = 0.548, p = 0.008). Increasing numbers of abnormal CT findings did not correlate with high-grade graft-versus-host disease (r = 0.117, p = 0.604). CONCLUSION: A variety of bowel abnormalities can be seen on CT in patients with acute graft-versus-host disease. CT findings associated with high-grade graft-versus-host disease are thickening of the distal esophagus, ileum, or ascending colon, as well as increasing numbers of thickened bowel wall segments.     

多层螺旋CT鉴别胃常见恶性肿瘤的意义

目的 回顾性分析胃常见恶性肿瘤的CT表现,探讨MSCT鉴别胃常见恶性肿瘤的意义.资料与方法 经手术病理证实的49例恶性胃肿瘤患者术前常规行MSCT增强扫描.两位放射科医师采用盲法对CT图像进行分析,评价病灶浸润胃壁的程度,病变处胃壁厚度,病灶累及范围,周围淋巴结肿大以及病变强化程度.结果 49例中,29例(59.1%)为腺癌,8例(16.3%)为淋巴瘤,12例(24.5%)为恶性间质瘤.腺癌主要表现为局限胃壁增厚或弥漫性浸润伴黏膜强化.淋巴瘤表现为局限于黏膜和黏膜下层的多区域侵犯,伴胃壁明显增厚和周围肿大淋巴结.恶性间质瘤的特征为突出于胃壁外的巨大肿块.结论 根据胃壁受累程度及侵犯区域,MSCT有助于鉴别三种较常见的胃恶性肿瘤.     

Mucinous cystadenocarcinoma of the lung: CT-pathologic correlation in three cases.

Mucinous cystadenocarcinoma (MCA) is a rare tumor that is considered to be a cystic variant of mucin-producing lung adenocarcinoma. MCA expands grossly by storing mucus and contains few neoplastic cells. We present the CT images of three patients with MCA and correlate them with pathologic specimens. The CT findings of MCA include a uniform low-attenuation, focal thickening of the cystic wall and enhancing septa.     

胃肠道淋巴瘤的CT影像表现

目的探讨原发性胃肠道淋巴瘤的CT表现及其诊断价值。方法分析17例经临床病理证实的原发性胃肠道淋巴瘤的CT表现。结果原发性胃淋巴瘤11例(浸润型6例、溃疡型2例、肿块2例及混合型1例),其CT表现及特征有:弥漫或局限性胃壁增厚,厚度不均,壁不光整,其增厚内缘呈分叶状或波浪状,3例浸润型中增厚胃壁内缘表面伴有深浅不一溃疡影,周围间隙存在,增强后呈轻中度强化。原发性小肠淋巴瘤5例(浸润型3例和肿块型2例)、原发性升结肠淋巴瘤1例。其CT征象为:肠壁呈局限性或广泛性不均匀增厚,可伴肠管管腔狭窄,壁柔软,无明显梗阻征象,增强后呈轻中度强化。其中2例见腹膜后及肠系膜血管周围增大淋巴结形成肿块,并包绕肠系膜血管及周围脂肪。结论原发性胃肠道淋巴瘤的表现多种多样,但有较为明显的CT表现及特征,正确掌握其表现特征将有助于胃肠道淋巴瘤的诊断。     

Gastrointestinal wall thickening in patients with cirrhosis: frequency and patterns at contrast-enhanced CT

PURPOSE: To determine the frequency and patterns of gastrointestinal wall thickening at contrast material-enhanced computed tomography (CT) in patients with cirrhosis. MATERIALS AND METHODS: Three radiologists retrospectively assessed the contrast-enhanced abdominal CT scans of 77 patients with cirrhosis and 100 patients without cirrhosis for gastrointestinal wall thickening from the stomach through the descending colon. The frequencies of wall thickening were determined in the cirrhosis and in the control groups and were compared by using the Fisher exact test. The segmental distribution, symmetry, and enhancement pattern were evaluated in all patients with cirrhosis and gastrointestinal wall thickening. RESULTS: Gastrointestinal wall thickening was seen in 49 (64%) patients with cirrhosis and in seven (7%) control subjects (P <.005). The jejunum and ascending colon were the most common sites of gastrointestinal wall thickening; each was involved in 32 (42%; 95% CI: 30%, 53%) patients. The scans of 30 (61%; 95% CI: 47%, 75%) patients with gastrointestinal wall thickening showed multisegmental distribution. Gastrointestinal wall thickening was concentric and homogeneous in all patients with cirrhosis. CONCLUSION: Gastrointestinal wall thickening is common on contrast-enhanced abdominal CT scans in patients with cirrhosis. It frequently involves multiple segments. The jejunum and ascending colon are the most common sites of involvement.