Colonic wall thickening in patients with cirrhosis: CT findings and clinical implications

OBJECTIVE: The purpose of this study was to determine the prevalence and spectrum of colonic wall changes in patients with cirrhosis and to determine the association between these colonic wall changes and portal hypertension. MATERIALS AND METHODS: Abdominal CT examinations of 57 patients with cirrhosis were evaluated for colonic abnormalities including bowel wall thickening and pneumatosis. The degree and extent of colonic involvement, other CT features of cirrhosis including ascites and portal hypertension, and clinical symptoms were recorded. A correlation was made with available colonoscopy, exploratory laparotomy, and pathologic results. RESULTS: Colonic wall abnormalities were seen in 37% (21/57) of the patients with cirrhosis, 25% (14/57) of whom had isolated or predominantly right-sided colonic changes. Abnormal bowel wall thickening (ranging from 6 mm to 3 cm in thickness) was present in 35% of the patients. Pneumatosis was found in 4% of the patients. Of the 18 liver transplant recipients who had CT examinations before and after liver transplantation, colonic changes were seen in 44% preoperatively but in only 6% postoperatively. Isolated right-sided colonic changes and diffuse colonic changes were associated with varices in 93% and 100% of the patients, respectively; with ascites in 93% and 100%, respectively; and with splenomegaly in 83% and 86%, respectively. Specific or focal bowel symptoms were present in only 29% of the patients with colonic changes, whether the changes were diffuse or isolated to the right side. CONCLUSION: Thirty-five percent of the patients with severe cirrhosis who underwent CT were shown to have colonic wall thickening; two thirds of these patients had thickening limited predominantly to the right colon. We postulated that predominantly right-sided colonic wall thickening may be related to changes in blood flow and hydrostatic pressures caused by portal hypertension. Many patients with isolated or predominately right-sided colonic wall thickening did not have specific or focal bowel symptoms, and in most patients, the colonic wall thickening resolved after successful liver transplantation, requiring no further testing. On the other hand, we found that pneumatosis or severe diffuse colonic wall thickening may indicate a more serious colonic problem such as ischemia or infection with Clostridium difficile and should prompt further investigation.     

Bowel wall thickening in patients with Crohn's disease: CT patterns and correlation with inflammatory activity

AIM: To assess CT patterns of bowel wall thickening in patients with Crohn's disease and to correlate these patterns with inflammatory activity. MATERIALS AND METHODS: We conducted a retrospective review of 58 helical abdominal CT scans of 53 patients with pathologically proven Crohn's disease. CT patterns of thickened bowel wall were divided into four types based on patterns of mural stratification and enhancement: type A, multilayered mural stratification; type B, two layers with strong mucosal enhancement and prominent low-density submucosa; type C, two layers without strong mucosal enhancement; and type D, homogeneous enhancement. We evaluated CT findings of the bowel and adjacent structures. We also reviewed pathologic features and clinical data to determine inflammatory activity. RESULTS: Fifty-five (95%) of 58 CT examinations showed bowel wall thickening. Of these 55 CT scans, type A pattern was found in 33 (60%), type B in 10 (18%), type C in five (9%), and type D in seven (13%). CT scans with type A showed significantly more wall thickening than those with either type C or type D. Histology revealed 43 cases with active disease and 12 with quiescent appearance. Thirty of 33 CT scans with type A and all 10 with type B were classified as acute disease, and three of five with type C and six of seven with type D as quiescent. CONCLUSION: In patients with Crohn's disease, CT patterns of bowel wall thickening correlated with inflammatory activity. Thickened bowel wall with layering enhancement is predictive of acute disease, and that of homogeneous enhancement suggests quiescence.     

Correlations between colonic wall thickening in patients with virally induced cirrhosis on CT and clinical status

PURPOSE: The purpose of this work was to determine the frequency and CT imaging spectrum of colonic wall thickening and correlate these with the clinical severity of virally induced cirrhosis. METHOD: Fifty-nine patients were identified with virally induced cirrhosis and no other causes of colonic wall thickening. The abdominal CT scans of these patients were retrospectively reviewed by two radiologists to determine the presence of colonic wall thickening from the ascending colon to the descending colon, to assess the segmental distribution, and to correlate these findings with the clinical status assessed by Child-Pugh classification, presence of ascites, splenic volume index, varices score, and serum albumin levels. RESULTS: Colonic wall thickening was identified in 18 (31%) patients. The frequency of the affected distribution of colonic wall thickening was as follows: ascending colon in 17 (29%) patients, transverse colon in 11 (19%) patients, and descending colon in 7 patients (12%). The ascending colon was the most common site of colonic wall thickening (p < 0.001). Ten (17%) patients had multisegmental distributions. Colonic wall thickening had a statistically significant association with Child-Pugh grades A, B, and C (p < 0.0001), presence of ascites (p < 0.0004), splenic volume index (p = 0.0026), varices score (p < 0.0001), and serum albumin levels (p = 0.0364). The segmental distribution of wall thickening significantly correlated with Child-Pugh grades A, B, and C (p = 0.0005), presence of ascites (p < 0.001), varices score (p < 0.0001), serum albumin levels (p < 0.0001), and splenic volume index (p = 0.0135). CONCLUSION: Colonic wall thickening occurs commonly in patients with virally induced cirrhosis. The presence and number of colonic wall thickening were correlated with the grading of the severity of cirrhosis.     

Appendiceal wall thickening at CT in asymptomatic patients with extraintestinal malignancy may mimic appendicitis

The purpose of this study was to describe the CT appearance and determine the prevalence of thick-walled appendices in patients with an extraintestinal primary malignancy. This potential mimic of appendicitis may occur in up to 2% of cancer patients. Awareness of this pitfall is important to avoid unnecessary laparotomy in this patient population.     

Colonoscopy findings in end-stage liver disease patients with incidental CT colonic wall thickening

OBJECTIVE: Colonic wall thickening may occur in patients with end-stage liver disease. This study was conducted to correlate colonoscopy with CT-detected colonic wall thickening in this group of patients to assess their radiologic and clinical relevance. CONCLUSION: Our results suggest that CT findings of colonic wall thickening in end-stage liver disease should be considered benign, and colonoscopy is unnecessary for the evaluation of malignancy or colitis unless it is clinically indicated.     

Frequency and CT patterns of bowel wall thickening proximal to cancer of the colon

OBJECTIVE: This study was performed to determine the frequency and patterns of colon wall thickening seen on CT of patients with adenocarcinoma of the colon. MATERIALS AND METHODS: Preoperative abdominal and pelvic CT scans of 185 patients with surgically proven adenocarcinoma of the colon were retrospectively evaluated by three abdominal radiologists for the presence of colon obstruction and colon wall thickening proximal to the colon adenocarcinoma. The distributions and patterns of colon wall thickening were categorized by consensus. CT findings were compared with pathologic findings. Fisher's exact test was used to determine the statistical significance of any associations. RESULTS: Of 185 patients, CT findings of 20 (10.8%) showed colon wall thickening. Of these, the adenocarcinoma obstructed the colon in 19 patients (p < 0.01). Colon obstruction was partial in 10 patients (53%) and complete in nine (47%). Colon wall thickening was contiguous to the tumor in 14 (70%) patients and noncontiguous in six (30%). Segmental and pancolonic, patchy and diffuse, and dependent and nondependent colon wall thickening was observed in 10 patients (50%) in each category. Associated small-bowel wall thickening was shown in 10 (50%) of the 20 patients. Pathologic examination showed colon wall thickening to be due to edema in all cases. CONCLUSION: Colon wall edema can occur proximal to colon adenocarcinoma, is almost always associated with colon obstruction, and is predominantly contiguous with the obstructing adenocarcinoma.     

Correlation of incidental colorectal wall thickening at CT compared to colonoscopy

Incidental colon wall thickening is a common finding on computed tomography (CT) scans obtained in patients presenting to the emergency department. Currently, there are no guidelines for the emergency department physician or primary care physician regarding the need for further evaluation, specifically colonoscopy, in these patients. A retrospective review of 2,850 abdominopelvic CT scans performed from April 2006 to September 2006 was conducted. Three hundred twenty-two patients had incidental colon wall thickening and 150 of these patients had a subsequent colonoscopy. This study focused on those 150 patients and analyzed the correlation between the CT scan findings of wall thickening of the colon and the findings on colonoscopy. The CT scan findings correlated with abnormal colonoscopic findings in 96 out of 150 (64%) of our cases. In a specific subgroup, 12 out of 12 (100%) of these CT scans were also noted to have a mass lesion, as well as colon wall thickening, all of which were consistent with an adenoma or carcinoma found on colonoscopy. Incidental colorectal wall thickening at CT scan is due to nonspecific colitis in majority of the cases. Admission to the hospital should be based upon criteria other than this incidental radiological finding. However, patients with colorectal wall thickening with a mass lesion at CT scan should be followed closely as inpatient or outpatient given the high correlation with significant findings on colonoscopy.     

胃壁增厚的CT表现

目的：探讨胃良恶性病变胃壁增厚的CT表现特征,提高良恶性鉴别能力。方法：回顾性分析经病理或临床诊断明确的42例胃壁增厚的CT表现,并以胃壁增厚的程度、对称性、强化特点和分布等以鉴别良恶性病变的特征性CT表现。结果：肿块型增厚19例;条状或带状增厚5例;溃疡型增厚5例;蒂型增厚1例;结节型增厚6例;不规则型增厚6例。其中,恶性15例,良性26例,未定型1例。结论：胃壁增厚在CT上表现直观、清晰,结合胃壁增厚的程度、类型、强化等特点可以鉴别其良恶性。     

Pericaval fat mimicking intracaval deposits on unenhanced and contrast-enhanced helical CT in patients with cirrhosis.

PURPOSE: The purpose of this work was to determine whether there is a significant difference in radiographic depiction of pericaval fat mimicking intracaval deposits on CT scans in patients with cirrhosis versus those without cirrhosis. METHOD: The incidence of radiographic pseudolesions depicted as an intracaval fat mass identified on CT scans in 62 patients with cirrhosis was compared with that in 81 patients without cirrhosis. RESULTS: Pericaval fat depicted as an intracaval fat mass was identified more frequently in patients with cirrhosis (20/62, 32%) than in patients without cirrhosis (4/81, 5%), representing a statistically significant difference (p < 0.0001). A total of 24 lesions were seen in 20 patients with cirrhosis. Lesions were identified at the confluence of the hepatic veins (n = 19), below the confluence (n = 4), and above the confluence (n = 1). Pseudolesions appeared round (n = 5), oval (n = 15), or linear (n = 4). Locations included medial (n = 15), posteromedial (n = 4), anteromedial (n = 1), and posterior (n = 4). The average length was 1.5 cm. CONCLUSION: The cause of pseudolesions depicted as intracaval fat masses on CT is likely secondary to morphologic changes in the liver such as cirrhosis.     

Enhancement patterns of intrahepatic cholangiocarcinoma: comparison between contrast-enhanced ultrasound and contrast-enhanced CT

The aim of this study was to compare the enhancement pattern of intrahepatic cholangiocarcinoma (ICC) on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). 40 pathologically proven ICC lesions in 40 patients were evaluated retrospectively with both CEUS and CECT. The enhancement level and pattern in the dynamic phases on both CEUS and CECT were analysed. The diagnostic results of CEUS and CECT before pathological examination were also recorded. During arterial phases, the number of lesions that appeared as (i) peripheral irregular rim-like hyperenhancement, (ii) diffuse heterogeneous hyperenhancement, (iii) diffuse homogeneous hyperenhancement and (iv) diffuse heterogeneous hypoenhancement were 19 (47.5%), 9 (22.5%), 5 (12.5%) and 7 (17.5%), respectively, on CEUS, and 22 (55.0%), 3 (7.5%), 2 (5.0%) and 13 (32.5%), respectively, on CECT (p = 0.125). In the portal phase, the number of lesions showing hyperenhancement and hypoenhancement were 1 (2.5%) and 39 (97.5%), respectively, on CEUS, and 15 (37.5%) and 25 (62.5%) on CECT (p = 0.0001). CEUS made a correct diagnosis in 32 (80.0%) lesions before pathological examination; CECT made a correct diagnosis in 27 (67.5%) lesions (p = 0.18). In conclusion, the enhancement patterns of ICC on CEUS were consistent with those on CECT in the arterial phase, whereas in the portal phase ICC faded out more obviously on CEUS than on CECT. CEUS had the same accuracy as CECT in diagnosing ICCs, and so can be used as a new modality for the characterization of ICC.     

肾动脉狭窄的肾脏CT血流灌注参数研究

目的:探讨利用CT血流灌注参数研究肾动脉狭窄患者肾脏血流状况。方法:高血压患者36人,分为肾动脉狭窄组(24人)和对照组(12人),进行肾脏CT电影扫描获得动态序列图像,通过AW影像工作站计算肾脏皮质血流灌注参数,分析肾脏皮质血流灌注与肾动脉狭窄的关系。结果:肾动脉狭窄>75%组肾皮质单位体积血流量(BF)(189.9±102.3ml/100g/min)低于对照组(308.4±99.9ml/100g/min),有显著差异(P=0.026)。肾动脉狭窄50%-75%组及狭窄>75%组肾皮质微血管容积(BV)(24.6±7.6ml/100g,21.4±12.6ml/100g)低于对照组(41.1±14.1ml/100g),有非常显著差异(P=0.008,0.001)。各组之间平均通过时间(MTT)、毛细血管表面通透性(PS)无显著性差异(P>0.05)。结论:明显肾动脉狭窄的肾脏皮质BF、BV下降,CT血流灌注参数可以为评估肾动脉狭窄的肾脏是否缺血提供帮助。     

CT evaluation of wall thickening in the alimentary tract

Computed tomography (CT) of the alimentary tract, when performed with adequate distention of the organ being examined and in the true axial plane, provides valuable information about the intramural or extramural extent of pathologic conditions. Neoplastic, vascular, and inflammatory diseases can all result in wall thickening of the alimentary tract. Wall thicknesses greater than 5 mm in the esophagus, stomach, and colon and 4 mm or greater in the small bowel are considered abnormal. If the thickened wall has a target or double-ringed appearance, it is most likely caused by benign disease. In general, the CT findings of asymmetric or focal wall thickening, nodularity, and thickening greater than 1.5 cm suggest a malignant process. Although it is commonly associated with benign disease, diffuse thickening can also result from some infiltrating malignant diseases. Careful review of CT scans for evidence of metastatic disease and adenopathy and correlation with clinical information aid in the differential diagnosis.     

囊性纤维病病人结肠壁冗余的CT表现

目的描述囊性纤维病(cystic fibrosis,CF)病人结肠壁冗余的表现、患病率和可能的并发症。材料与方法本研究得到临床医学伦理委员会同意,并遵从HIPAA。回顾性分     

Helical CT screening for hepatocellular carcinoma in patients with cirrhosis: frequency and causes of false-positive interpretation

OBJECTIVE: The purpose of our study was to determine the specificity of helical CT for depiction of hepatocellular carcinoma in a population of patients with cirrhosis. SUBJECTS AND METHODS: Single-detector helical CT screening was undertaken in 1329 patients with cirrhosis who were referred for transplantation. The patients underwent one or more helical CT examinations over 30 months and were followed up for an additional 19 months or until transplantation. We predominantly used unenhanced and biphasic contrast-enhanced techniques with infusions of 2.5-5.0 mL/sec. Four hundred thirty patients underwent transplantation within this period. Liver specimens were sectioned at 1-cm intervals, with direct comparison of imaging and pathologic findings and histologic confirmations of all lesions. Prospective preoperative helical CT reports were used for the primary data analysis. A retrospective unblinded review was undertaken to determine characteristics of false-positive lesions diagnosed as hepatocellular carcinoma. RESULTS: Thirty-five patients (8%) had false-positive diagnoses for hepatocellular carcinoma based on helical CT. Twenty of these patients (5%) showed hypoattenuating lesions seen during one of the three helical CT examination phases. Fifteen patients (3%) had hyperattenuating lesions seen during the arterial phase. Among the 15 hyperattenuating lesions, CT revealed the causes to be transient benign hepatic enhancement (n = 3), hemangiomas (n = 2), fibrosis (n = 2), peliosis (n = 1), volume averaging (n = 1), low-grade dysplastic nodule (n = 1), or undetermined (n = 5). Of the 20 hypoattenuating lesions, the causes were shown to be fibrosis (n = 8), focal fat (n = 4), infarcted regenerative nodules (n = 2), regenerative nodules (n = 1), fluid trapped at the dome of the liver (n = 1), hemangioma (n = 1), or undetermined (n = 3). Follow-up helical CT in 13 (72%) of 18 patients allowed a change in the diagnosis of hepatocellular carcinoma to a finding of no cancer present. CONCLUSION: Helical CT screening for hepatocellular carcinoma in patients with cirrhosis has a substantial false-positive detection rate. Although most of lesions were hypoattenuating, a few hyperenhancing arterial phase lesions were proven not to be hepatocellular carcinoma. An awareness of imaging characteristics and follow-up imaging can help radiologists avoid a mistaken diagnosis in many patients.     

Segmental wall thickening in the colonic loop distal to colonic carcinoma at CT: importance and histopathologic correlation

PURPOSE: To determine the importance of the finding of segmental wall thickening in the colonic loop distal to colonic carcinoma at computed tomography (CT) by means of histopathologic correlation. MATERIALS AND METHODS: Thirteen consecutive patients whose helical CT scans showed segmental wall thickening (>1 cm in maximal width, >5 cm in length) in the colonic loop distal to colonic carcinoma were included. The thickness and length of an involved segment, location, morphologic tumor type, CT patterns of wall thickening, and pericolic changes were evaluated. Surgical pathologic findings in all 13 patients were correlated with CT findings. RESULTS: The involved segment distal to the colonic carcinoma showed circumferential wall thickening with a preserved wall layer pattern at CT. Pericolic changes of varying degrees were seen in 10 patients. Histopathologic examination revealed submucosal and subserosal edema (n = 6), chronic inflammation and fibrosis (n = 5), or both (n = 1), and no histopathologic alteration (n = 1). The tumors were mostly fungating (n = 11), larger than 5 cm in the greatest dimension (n = 12), located in the ascending colon (n = 10), and extended to pericolic adipose tissue (n = 11). CONCLUSION: Colonic carcinoma, especially a large fungating type involving the ascending colon with pericolic infiltration, can produce segmental wall thickening in the distal segment at CT, which represents edema or colitis at histopathologic examination.     

Gallbladder wall thickening: patients without intrinsic gallbladder disease

Retrospective analysis of 22 patients with increased gallbladder wall thickness (4--10 mm) in the absence of gallbladder disease revealed that 19 were hypoalbuminemic (albumin less than 3.6 g/dl). To test the hypothesis that hypoalbuminemia was a causal factor, gallbladder wall thickness was measured in 40 patients selected prospectively solely on the basis of hypoalbuminemia. This group was compared to 25 normal volunteers. Hypoalbuminemic patients had significantly thickened gallbladder walls compared to volunteers (p less than 10(-9)). This thickening was associated not only with hypoalbuminemia, but also with increased main portal vein diameter, which reflects portal venous blood pressure. Gallbladder wall thickening unrelated to intrinsic gallbladder disease seems to be influenced by the same parameters as ascites formation--plasma colloid oncotic pressure and portal venous pressure.     

Enhancement patterns of focal liver masses: discordance between contrast-enhanced sonography and contrast-enhanced CT and MRI

OBJECTIVE: The purpose of this study was to investigate the origin of the infrequent discordance between the contrast enhancement patterns of liver lesions on sonography and those on CT and MRI. Forty-four discordant cases were reviewed retrospectively. CONCLUSION: Four categories of discordance were identified, one of which is unexplained. Contrast agent diffusion caused portal venous phase discordance in malignant tumors (n = 6) whereby CT and MRI contrast material diffused through the vascular endothelium into the tumor interstitium, concealing washout. Sonographic microbubbles were purely intravascular and showed washout. Arterial phase timing discordance occurred in metastatic lesions (n = 10) with hypervascularity and rapid washout on contrast-enhanced sonography. CT arterial imaging performed later showed hypovascularity. Rapidly enhancing hemangiomas (n = 7) exhibited hypervascularity on CT when contrast-enhanced sonography also showed peripheral nodules and fast centripetal progression. Discordance caused by fat in lesions (n = 4) or liver (n = 10) reflected the inherent echogenicity of fat on sonography compared with its low attenuation on CT and low signal intensity on MRI. Infrequent cases of discordance remain unexplained. Recognition of the cause of the infrequent disagreement in enhancement patterns on contrast-enhanced sonography with those on CT and MRI improves diagnostic interpretation.