Small-bowel disease: categorization by CT examination

Fifty patients with no small-bowel disease were evaluated by CT to determine the normal appearance of the small bowel and mesentery. Subsequently, the CT findings in 95 patients with proven small-bowel disease were analyzed to determine which CT observations correlated with neoplastic, inflammatory, or edema-producing processes. Thirty-three (83%) of 40 patients with wall thickening or mesenteric masses greater than 1.5 cm had a neoplastic process. Twenty-eight (82%) of 34 patients with normal mesenteric fat attenuation, wall thickening less than 1.5 cm, or mesenteric masses less than 1.5 cm had inflammatory disease. Fourteen (67%) of 21 patients with no mesenteric mass, increased mesenteric fat attenuation, and wall thickening less than 1.5 cm had noninflammatory edema. Overall, CT assigned 75 (79%) of 95 patients into appropriate categories; use of ancillary CT findings led to correct categorization in 83 (87%). CT is helpful in correctly assigning a disease category to patients with small-bowel wall thickening.     

Small bowel disease in children: diagnosis with CT

The computed tomographic (CT) scans of 22 children with small bowel disease and those of 110 children with no small bowel disease were analyzed by two observers who were blinded with respect to clinical history and final diagnoses in order to determine which CT findings reliably indicated neoplastic, inflammatory, or noninflammatory processes. Bowel-wall thickening was the most reliable sign of disease. Five of six patients (83%) with bowel-wall thickness greater than 1 cm had neoplastic disease. Nine of ten patients (90%) with bowel-wall thickness between 3 mm and 1 cm had inflammatory disease, while four of six patients (66%) with wall thickness less than 1 cm and increased attenuation of mesenteric fat or an increase in the number of mesenteric vessels had noninflammatory edema. The presence of mesenteric masses was not a helpful sign for differentiating various disease processes. The results of this retrospective study suggest that the identification and classification of small bowel disease in children is possible from the objective analysis of CT findings.     

Computed tomography of peripancreatic fat planes

Obliteration of peripancreatic fat planes usually is considered an indicator of peripancreatic tumour infiltration in the presence of a malignant mass, or of inflammation of peripancreatic tissues in patients with pancreatitis. However, absence of peripancreatic fat planes also may be found in patients without evidence of pancreatic disease. Hence, CT scans of 125 patients without clinical or computed tomographic evidence of pancreatic disease were evaluated to assess normal variations in the anatomy of the pancreas and its relation to surrounding vessels and bowel loops. The fat plane separating the superior mesenteric artery from the pancreas was preserved in 100% of patients. Conversely, fat planes between the pancreas and the superior mesenteric vein, inferior vena cava, and adjacent bowel loops were partially or totally obliterated in 13% to 50% of patients. It is concluded that the absence of fat around the superior mesenteric artery is highly suggestive of pathologic changes of the pancreas, while the lack of fat planes between the pancreas and other splanchnic vessels or bowel loops frequently is normal, and therefore, is an unreliable sign of pancreatic disease. The applications of these findings to the assessment of tumour resectability by CT, and to CT scanning techniques, are discussed.     

CT density of mesenteric, retroperitoneal, and subcutaneous fat in cirrhotic patients: comparison with control subjects

We determined the density in Hounsfield units of the mesenteric, retroperitoneal, and subcutaneous fat on CT scans made in 41 patients with biopsy-proved cirrhosis and compared the results with the density of the fat in these locations in 34 control subjects, in an attempt to quantify changes in fat density in patients with cirrhosis. The mean densities of mesenteric, retroperitoneal, and subcutaneous fat in patients with cirrhosis were -56, -107, and -111 H, respectively. The corresponding mean densities in control subjects were -107, -118, and -124 H. The mean density of mesenteric fat in patients with cirrhosis was 50% greater than that of their subcutaneous fat (p less than .0001), 48% greater than that of their retroperitoneal fat (p less than .0001), and 48% greater than that of the mesenteric fat in control subjects (p less than .0001). The mean density of subcutaneous fat in the anterior abdominal wall in patients with cirrhosis was -96 H compared with -119 H for that in their posterior abdominal wall. The corresponding mean densities in control subjects were -109 and -131 H. Density of subcutaneous fat in the anterior abdominal wall for all subjects (patients and controls) was 18% greater than that of subcutaneous fat in the posterior abdominal wall (p less than .05). In all locations, the statistical trend was for patients with cirrhosis to have higher density fat than did control subjects. These changes in density are thought to represent diffuse fat edema, most prominently in the mesentery because of portal hypertension.     

Radiologic investigation of renal colic: unenhanced helical CT compared with excretory urography.

OBJECTIVE: Our aim was to compare unenhanced helical CT and excretory urography in the assessment of patients with renal colic. SUBJECTS AND METHODS: Fifty-three of 70 consecutive patients with acute signs of renal colic were prospectively examined with unenhanced helical CT, which was followed immediately by excretory urography. Two radiologists who were unaware of the findings independently interpreted these examinations to determine the presence or absence of ureteral obstruction. On all CT scans that had positive findings for ureteral stones or obstruction, we looked for secondary signs of obstruction (perinephric or periureteral fat stranding, ureteral wall edema, ureteral dilatation, and blurring of renal sinus fat). RESULTS: A stone was recovered in 45 of the 53 patients, nine before and 36 after imaging. The latter 36 patients had their stones identified on CT, whereas only 24 patients had their stones identified on excretory urography. Eight patients without stone disease had normal ureters on both CT and excretory urography. Of the 45 patients who had stone disease, 26 had ureteral dilatation on both CT and excretory urography, and 36 patients who recovered a stone after CT had secondary signs of obstruction. Of the nine patients who recovered a stone before CT, three had secondary signs of obstruction. Two patients had periureteral fat stranding, ureteral wall edema, and renal sinus fat blurring. One patient had only ureteral wall edema. CONCLUSION: Compared with excretory urography, unenhanced helical CT is better for identifying ureteral stones in patients with acute ureterolithiasis. Secondary CT signs of obstruction, including renal sinus fat blurring, were frequently present even when the stone was eliminated before imaging.     

肠系膜脂膜炎MSCT影像学表现

目的 分析肠系膜脂膜炎的MSCT特点,提高CT诊断及鉴别诊断的水平.方法 回顾性分析12例肠系膜脂膜炎的临床及MSCT表现.5例CT平扫,7例CT平扫加双期增强检查,12例均按照CT诊断标准诊断为肠系膜脂膜炎（1例手术证实）.结果 12例表现为围绕肠系膜根部及走形区域边界清楚的脂肪肿块,呈云雾状密度增高影.7例增强扫描病灶未见强化,病变与腹腔内脂肪和腹膜后脂肪分界清晰.9例可见“假包膜”征,6例见“脂肪环”征.6例病变对邻近肠袢有推移征象,其中1例导致小肠梗阻,1例病变伴门静脉及肠系膜上静脉部分栓塞.3例病变内及后腹膜见小结节.12例病变肿块内均无囊性变及钙化灶.结论 肠系膜脂膜炎CT表现具有一定特征,MSCT是诊断肠系膜脂膜炎非常有效的影像手段.     

CT征象对胃肠间质瘤恶性程度预测的诊断价值

目的:探讨CT征象与胃肠间质瘤(gastrointestinal stromal tumors,GIST)恶性程度的相关性。方法:回顾性分析36例手术病理证实的胃肠道间质瘤的CT表现,对照病理组织学分级,主要观察病变的发病部位、大小、形态、生长方式、密度、强化程度、周围有无淋巴结转移、邻近器官有无受侵、有无远处转移灶等方面。结果:36例GIST肿块大小不一,肿块大小与恶性程度密切相关(P<0.05)。病灶形态与恶性程度无统计学差异(P=0.870)。肿块生长方式与恶性程度无统计学差异(P=0.601)。肿瘤强化程度与恶性程度关系见表3,无明显统计学差异(P>0.05)。本组资料出现"牛眼征"(肿块明显不均匀强化,缺血和坏死部分呈低密度,其余实质呈高密度增强)的交界组50%、恶性组83%。肿瘤强化方式与恶性程度差异有统计学意义(P<0.05)。2例网膜肿块与周围组织粘连分界不清。有3例肝内转移,1例腹腔广泛种植转移;36例均未见淋巴结转移表现。结论:肿块的部位、大小、密度、牛眼征,强化方式单因素分析均有统计学意义;肿块的形态、边缘、强化程度和生长方式对胃肠间质瘤恶性程度评估无统计学意义。通过逐步回归分析肿块大小对胃肠间质瘤良恶性判断最有特异性,且肿块直径大于5cm并出现"牛眼征"时,可明确的诊断为恶性GIST。     

双源CT双期增强血管成像对急性肠缺血的诊断

目的:探讨双源CT(DSCT)双期增强扫描血管成像对急性肠缺血(acute mesenteric ischemia,AMI)患者的诊断价值。方法:回顾性分析经手术或介入治疗证实的26例AMI患者的DSCT资料。所有患者均行DSCT双期增强扫描即动脉期和门静脉期血管成像。结果:肠系膜上动脉栓塞8例,肠系膜上动脉血栓形成4例,肠系膜上静脉血栓形成14例。CT直接征象为肠系膜血管内低密度充盈缺损,受累血管腔闭塞(17例)或重度狭窄(9例)。间接征象:肠壁增厚(21例),肠管扩张、肠腔内积液积气(18例),肠壁强化程度降低(7例),肠壁积气(5例),肠系膜脂肪水肿及渗出(19例),"缆绳征"14例,腹腔积液12例。结论:DSCT增强扫描及双期血管成像可清楚显示AMI血管阻塞的部位、范围、程度及继发改变,对明确诊断和指导治疗具有较高的应用价值。     

肝硬化患者肠系膜、网膜及腹膜后水肿的CT表现及相关性分析

目的：探讨研究肝硬化患者肠系膜、网膜及腹膜后水肿的CT表现及相关性。方法：回顾分析经手术活检病理证实的62例肝硬化,62例均作腹部CT扫描,从腹部CT表现评估肠系膜、网膜及腹膜后水肿的分布、结构及严重性,对其表现进行相关性分析。结果：48例（77．4％）患者有肠系膜或网膜或腹膜后水肿,其中15例并发胸腔和（或）腹腔积液。46例患者有肠系膜水肿,其中单纯性肠系膜水肿18例,并发网膜或腹膜后水肿28例。1例患者单纯性网膜及腹膜后水肿。肠系膜并发网膜或腹膜后水肿与肠系膜水肿呈中重度改变及弥漫性分布均具有显著性相关（P〈0．01）,中重度肠系膜水肿与肠系膜水肿弥漫性分布及团块状改变均具有显著性相关（P〈0．01）。结论：肠系膜、网膜及腹膜后水肿是肝硬化的常见表现,三种水肿之间具有一定的相关性,CT对其诊断和特征描述有很大的价值。     

Mesenteric, omental, and retroperitoneal edema in cirrhosis: frequency and spectrum of CT findings.

PURPOSE: To determine the frequency and CT imaging spectrum of mesenteric, omental, and retroperitoneal edema in patients with cirrhosis. MATERIALS AND METHODS: Eighty patients were identified with liver cirrhosis and no other cause of edema. Five radiologists jointly reviewed the abdominal CT scans of these patients to assess, by majority decision, the presence, severity, distribution, and configuration of mesenteric edema and the presence of omental and retroperitoneal edema. Subcutaneous edema, ascites, pleural effusion, splenomegaly, varices, portal venous thrombosis, and serum albumin levels were also documented. RESULTS: Mesenteric edema was present in 69 (86%) patients. Mesenteric edema occurred alone in 26 (38%) and with omental or retroperitoneal edema in 40 (58%) of the 69 patients with edema. No patient had omental or retroperitoneal edema alone. Mesenteric edema was mild in 51 (74%) and moderate to severe in 18 (26%), patchy in 47 (68%) and diffuse in 22 (32%), purely infiltrative in 60 (87%) and infiltrative with superimposed masslike nodules in nine (13%) patients. These parameters had significant associations among themselves and with ascites, pleural effusions, subcutaneous edema, and low mean serum albumin levels but not with splenomegaly or varices. CONCLUSION: Mesenteric, omental, and retroperitoneal edema occur commonly in patients with cirrhosis. The appearance of mesenteric edema varies from a mild infiltrative haze to a severe masslike sheath that engulfs the mesenteric vessels.     

Gastrointestinal stromal tumors of the stomach: CT findings and prediction of malignancy

OBJECTIVE: The purpose of this study was to identify predictors of malignancy on CT for the evaluation of gastrointestinal stromal tumors of the stomach. MATERIALS AND METHODS: The medical records at our institution of 81 patients with a histologic diagnosis of gastrointestinal stromal tumor of the stomach were reviewed. Two radiologists retrospectively reviewed the CT findings by consensus with respect to lesion size, contour, tumor growth pattern, enhancing pattern, degree of enhancement, mesenteric fat infiltration, ulceration, calcification, lymphadenopathy, direct invasion to adjacent organ, and distant metastasis. Categoric variables were compared using the chi-square or Fisher's exact test. Multiple stepwise logistic regression analysis by means of forward selection was performed to determine significant predictors of high mitotic rate. Univariate analysis and multivariate analysis were also performed in a subgroup of 36 tumors with maximal diameter of 5 cm or smaller. RESULTS: Size, presence of an ulcer, mesenteric fat infiltration, direct organ invasion, and metastasis were more frequently observed during univariate analysis in tumors with a high mitotic rate (p < 0.05). With stepwise logistic regression analysis, the size (odds ratio, 2.57; 95% CI; 1.42-4.67) was the only significant predictor of a high mitotic rate. In a subgroup of 36 tumors 5 cm or smaller, differentiation of benign from malignant tumors was not possible using CT. CONCLUSION: Although presence of an ulcer, mesenteric fat infiltration, direct organ invasion, and metastasis were more frequently observed in tumors with a high mitotic rate, no CT feature, other than size, was found to have predictive value with respect to malignant gastrointestinal stromal tumors of the stomach.     

Computerized tomography features of intestinal infarction: 56 surgically treated patients of which 5 with reversible mesenteric ischemia]

PURPOSE: Bowel infarction is a rare and typical condition of the elderly; despite improvements in diagnostic imaging and vascular surgery, bowel infarction remains a major cause of acute abdomen, with mortality rates ranging 70-80%. Diagnosis is often late because clinical signs, laboratory data and radiologic findings are aspecific. We investigated radiographic and particularly CT patterns of intestinal infarction in 56 patients submitted to surgery within 12 hours of admission. We also report the CT findings of 5 of these patients who had reversible mesenteric ischemia. MATERIAL AND METHODS: We retrospectively reviewed 56 cases of bowel infarction. The patients were 29 men and 27 women ranging in age 46-84 years (mean: 63). All the patients were submitted to plain radiography of the abdomen in different projections; emergency CT was carried out with i.v. contrast agent injection. We considered the following CT patterns: dilatation of intestinal loops > 2.5-3 mm, wall thickening > 3-4 mm, intraperitoneal effusion, stuffing of mesenteric vessels with diameter > 3 mm, air-fluid levels. RESULTS: Patients in the 7th decade of life were most frequently affected (38 cases), with an overall mortality rate of 59% (33 deaths). Plain radiography showed distention of bowel loops with air-fluid levels in 91% of cases. CT proved to be an accurate technique with higher sensitivity than radiography in detecting mesenteric edema and hemorrhage (68%), abdominal and pelvic effusion (88%), parietal pneumatosis (9%), wall thickening (29%), intraportal gas (7%), and thrombosis of superior mesenteric artery (3.5%). CT patterns in the 5 patients with reversible intestinal ischemia were wall thickening (80%), peritoneal effusion (80%), meteoric dilatatation (40%), a blurred appearance of mesenteric fat (40%). CONCLUSIONS: Angiography is a valuable imaging and treatment technique permitting the diagnosis of vascular occlusion and the intraarterial infusion of vasodilators, but it can be carried out in emergency in few centers only. This makes conventional radiology, and particularly CT, the only tool providing useful information for early diagnosis and treatment of bowel infarction. CT is more sensitive than radiography and does not exhibit the limitations of angiography--i.e., invasiveness, radiation exposure and complex organization. Therefore CT can presently be considered the method of choice in patients with suspected bowel infarction.     

Analysis of mesenteric thickening on computed tomography

Computed Tomography (CT) provides a noninvasive information in the evaluation of abnormalities of the gastrointestinal tract by direct imaging of the bowel wall and adjacent mesentery. Several prior studies have discussed the variable CT appearances of mesenteric abnormalities, such as lymphoma, metastasis, inflammatory disease and edema. Although mesenteric thickening was mentioned in these studies, no study has provided a detailed analysis of the CT appearance of the thickened mesentery. Two characteristic types of mesenteric thickening were identified in 47 patients. Type I is "Intra-mesenteric thickening", which was noted in 25 patients with vascular obstruction, inflammatory disease and edema. Type II is "Mesenteric surface thickening", which was noted in 22 patients with peritonitis carcinomatosa, peritoneal mesothelioma, tuberculous peritonitis and pseudomyxoma peritoneal. An understanding of these two types of mesenteric disease is important in the identification of mesenteric pathology.     

CT对肠系膜损伤的评价研究

目的 评价腹部CT对肠系膜损伤的诊断价值。方法 回顾14例经手术证实肠系膜损伤患者临床资料和CT检查结果，分析腹膜腔内游离积液、肠系膜脂肪内渗出、肠系膜血肿、造影剂血管外溢和肠壁增厚强化等CT征象，并结合手术结果确定CT表现对诊断肠系膜损伤的敏感性。结果 所有14例患者的CT图像均显示有腹膜腔游离积液或积血和肠系膜脂肪内渗出，其中12例可见肠系膜内血肿，2例显示有肠壁增厚强化，1例可见造影剂血管外溢，且CT表现与手术结果一致。结论 CT对于肠系膜损伤的诊断具有很好的敏感性，其CT表现有助于判断损伤的部位。     

失代偿期肝硬化CT显示腹膜和腹膜后组织水肿的临床意义

目的　探讨失代偿期肝硬化腹膜和腹膜后水肿CT表现特点及临床意义。方法　 44例经临床和实验室检查证实为失代偿期肝硬化 (DCC)。根据腹膜和腹膜后水肿的范围 ,分为轻、中、重3级 ,并观察腹水及其量和静脉曲张的情况。将上述指标与血清白蛋白 (ALB)和透明质酸 (HA)水平进行相关分析。结果　腹膜和腹膜后水肿的程度与血清ALB降低的程度 (rs=0 70 88,P <0 0 0 1)、血清HA升高的程度 (rs=0 5 2 94,P <0 0 1)和腹水量 (rs=0 5 44 0 ,P <0 0 0 5 )有明显的相关性。而与静脉曲张形成无相关性 (rs=0 1335 ,P >0 .0 5 )。结论　DCC病人CT显示腹膜和腹膜后水肿 ,在一定程度上可反映肝硬化病变的程度。     

Acute ureterolithiasis: nonenhanced helical CT findings of perinephric edema for prediction of degree of ureteral obstruction

PURPOSE: To determine whether the extent of perinephric edema on helical computed tomographic (CT) images without contrast material enhancement can be used to predict the degree of ureteral obstruction in patients with acute ureterolithiasis. MATERIALS AND METHODS: Nonenhanced helical CT and excretory urographic images in 82 patients with flank pain were retrospectively reviewed. For each patient, a radiologic diagnosis was established, and the degree of ureteral obstruction determined on urograms was compared with the extent of perinephric edema assessed on CT images. RESULTS: None of 29 patients with no abnormalities seen at urography had evidence of perinephric edema at CT. Of six patients with noncalculous disease, two with acute pyelonephritis had perinephric edema at CT. Of 47 patients with acute ureterolithiasis, eight had no perinephric edema at CT and a nonobstructing calculus at urography, 21 had limited edema at CT and low-grade obstruction at urography, and 15 had extensive edema at CT and high-grade obstruction at urography. Three patients had extensive perinephric edema at CT but low-grade obstruction at urography. The extent of edema allowed accurate prediction of the degree of ureteral obstruction in 44 (94%) of 47 patients with acute ureterolithiasis. CONCLUSION: The extent of perinephric edema on nonenhanced helical CT images can be used to predict the degree of ureteral obstruction in acute ureterolithiasis.     

Computed tomography of bowel infarction

Bowel infarction is a potentially lethal disorder that is notoriously difficult to diagnose clinically and radiographically. Computed tomography is often used in the early radiographic evaluation of patients with severe abdominal pain of unknown etiology. This study defines the CT findings in patients with bowel infarction. The findings in 22 patients with mesenteric infarction were reviewed. Seven were due to mesenteric arterial occlusion, six due to mesenteric venous occlusion, and nine were nonocclusive. The CT abnormalities were diffuse or focal bowel wall thickening (19 patients), bowel dilatation without mural thickening (three patients), intramural low attenuation zones of edema (eight patients), intramural gas (11 patients), mesenteric gas (five patients), portal or mesenteric venous gas (one patient), mesenteric vascular occlusion (eight patients), and peritoneal gas or fluid (12 patients). The diagnosis of bowel infarction must be considered when performing CT in patients with abdominal pain of unknown etiology.     

绞窄性肠梗阻肠系膜及其血管改变的CT研究

目的对经CT检查、有肠系膜及其血管（MRV）改变的30例绞窄性肠梗阻（SO）进行分析，探讨CT诊断的临床价值。方法30例SO，均行CT平扫，其中20例行增强扫描，均显示有不同形式的MRV改变。26例经手术、4例经临床证实，包括粘连性肠梗阻9例，肠扭转8例，肠套叠6例，肠系膜血管闭塞性肠梗阻4例，内疝3例。结果所有病例经CT检查可发现11种CT征象，并可分作：（1）直接征象：包括肠系膜血管闭塞2例，肠系膜水肿及其血管增粗并形态异常19例；（2）间接征象：包括肠壁水肿增厚24例，CT强化肠壁异常6例，肠腔大量积液13例，肠袢特殊形态10例，肠壁、肠系膜出血各1例；（3）并发症征象：包括肠壁间积气3例，肠系膜门脉积气1例，肠系膜积气1例，腹水和气腹共11例。结论急腹症CT检查如能显示MRV改变，结合其他CT征象和临床，可以对SO术前作出诊断。同时也能观察到传统x线不能显示的并发症。     

Computed tomography of the normal mesentery

Thirty patients were studied to evaluate the CT appearance of the normal mesentery and its vasculature. Mesenteric vessels were identified by determining their relations to segments of the small bowel and colon in the 30 patients. Jejunal and ileal branches supplying small bowel were identified in all patients. The ileocolic and right colic branches of the ascending colon were identified in 27 and 26 patients, respectively; middle colic vessels were identified in 29 patients. Left colic branches were identified in only 14 patients; sigmoid branches were identified in 23 patients. The vessels showed a characteristic wavy appearance as they coursed through mesenteric fat. The average attenuation of the mesenteric fat was -117.4 +/- 7.9 H. Normal lymph nodes were not routinely identified within the mesentery. Various pathologic processes altered the normal appearance of the components of the mesentery.     

肠系膜脂膜炎CT诊断

目的 探讨肠系膜脂膜炎的CT特点,提高CT诊断水平.方法分析7例按照CT诊断标准诊断为肠系膜脂膜炎患者的临床资料和CT表现.结果 7例表现为围绕小肠系膜根部边界清楚的脂肪肿块,增强扫描未见强化.病变与腹腔脂肪和腹膜后脂肪分界清楚.7例可见"假包膜"征,5例见"脂肪环"征.2例病灶内可见肿大淋巴结影,2例可见腹膜后淋巴结肿大,4例有腹部手术史, 1例合并胰头癌.结论肠系膜脂膜炎CT表现具有一定特征,CT是诊断肠系膜脂膜炎有效的影像手段.