CO2 or air cholangiography reduces the risk of post-ERCP cholangitis in patients with Bismuth type IV hilar biliary obstruction.

BACKGROUND: Endoscopic biliary stenting by endoscopic retrograde cholangiopancreatography (ERCP) is the most common form of palliation for malignant hilar obstruction. However, ERCP in such cases is associated with a risk of cholangitis. The incidence of post-ERCP cholangitis is particularly high in Bismuth type IV hilar obstruction, and this risk is further increased when the contrast injected for cholangiography is not drained. The present study aims to compare the incidence of cholangitis associated with the use of a contrast agent, air and CO2 for cholangiography in type IV hilar biliary lesions. METHODS: The clinical data of consecutive 70 patients with type IV hilar obstruction, who underwent ERCP from October 2013 to November 2017, were retrospectively analyzed. These patients were divided into three groups based on the agent used for cholangiography: group A, contrast (n = 22); group B, air (n = 18); group C, CO2 (n = 30). These three methods of cholangiography were chronologically separated. Prior to the ERCP, MRCP was obtained from all patients to guide the endoscopic intervention. RESULTS: At baseline, there was no significant difference in terms of the patient's age, gender, symptoms and liver function tests among the three groups (P > 0.05). The complication rates were significantly higher in group A than in groups B and C (63.6% vs. 26.7 and 27.8%, P < 0.05). The incidence of post-ERCP cholangitis was significantly higher in group A (P < 0.05), while the incidence of post-ERCP pancreatitis and bleeding were similar in the three groups. After the ERCP, the mean hospital stay was shorter in groups B and C, when compared to group A (P < 0.05). However, there was no significant difference in the 30-day mortality rate among the three groups (P > 0.05). Furthermore, there was no significant difference between groups B and C in terms of primary end points. CONCLUSION: CO2 or air cholangiography during ERCP for type IV hilar obstruction is associated with reduced risk of post-ERCP cholangitis, when compared to conventional contrast agents.

Diagnostic accuracy of pneumo-CT-cystography in the detection of bladder rupture in patients with blunt pelvic trauma.

PURPOSE: To evaluate the diagnostic utility of bladder air distension (pneumo-CT-cystography) in the detection of bladder rupture in patients with blunt pelvic trauma. MATERIALS AND METHODS: 843 patients with blunt pelvic trauma were evaluated. Intravenous contrast-enhanced CT was performed for trauma staging. 97 of 843 patients had clinical and radiological signs of possible bladder injury and underwent retrograde air distension. RESULTS: Among 97 patients, 31/97 showed CT signs of bladder rupture, of which 5/31 (16%) intraperitoneal, 25/31 (81%) extraperitoneal and 1/31 (3%) combined. 23 of these patients underwent surgery, which confirmed bladder injury in 100% of cases. The other 8 patients were managed conservatively, and follow-up studies showed disappearance of free air. Among the 66/97 patients with no signs of bladder injury, 38/66 had surgery, which confirmed bladder integrity, while 28/66 were managed conservatively and showed no signs of bladder rupture at clinico-radiological follow-up examinations. CONCLUSIONS: CT evaluation of urinary bladder after retrograde air distension (pneumo-CT-cystography) may be a reliable diagnostic tool in the detection of bladder rupture in patients with blunt pelvic trauma. This technique is faster, cheaper and allows to overcome some of the limitations of conventional CT-cystography.

Is Intussusception a Middle-of-the-Night Emergency?

OBJECTIVES: Intussusception is the most common abdominal emergency in pediatric patients aged 6 months to 3 years. There is often a delay in diagnosis, as the presentation can be confused for viral gastroenteritis. Given this scenario, we questioned the practice of performing emergency reductions in children during the night when minimal support staff are available. Pneumatic reduction is not a benign procedure, with the most significant risk being bowel perforation. We performed this analysis to determine whether it would be safe to delay reduction in these patients until normal working hours when more support staff are available. METHODS: We performed a retrospective review of intussusceptions occurring between January 2010 and May 2015 at 2 tertiary care institutions. The medical record for each patient was evaluated for age at presentation, sex, time of presentation to clinician or the emergency department, and time to reduction. The outcomes of attempted reduction were documented, as well as time to surgery and surgical findings in applicable cases. A Wilcoxon rank test was used to compare the median time with nonsurgical intervention among those who did not undergo surgery to the median time to nonsurgical intervention among those who ultimately underwent surgery for reduction. Multivariable logistic regression was used to test the association between surgical intervention and time to nonsurgical reduction, adjusting for the age of patients. RESULTS: The median time to nonsurgical intervention was higher among patients who ultimately underwent surgery than among those who did not require surgery (17.9 vs 7.0 hours; P < 0.0001). The time to nonsurgical intervention was positively associated with a higher probability of surgical intervention (P = 0.002). CONCLUSIONS: Intussusception should continue to be considered an emergency, with nonsurgical reduction attempted promptly as standard of care.

Utility of minimal preparation computed tomography colonography in detecting colorectal cancer in elderly and frail patients.

BACKGROUND: Colorectal cancers result in substantial morbidity and mortality to the Australian society each year. The usual investigation for bowel malignancy is optical colonoscopy (OC), with computed tomography colonography (CTC) used as an alternative investigation. The catharsis and colon insufflation associated with these investigations pose a higher risk in the elderly and frail. Risks include perforation, serum electrolyte disturbance and anaesthesia/sedation risks. Minimal preparation computed tomography colonography (MPCTC) eliminates these risks. AIMS: To audit the accuracy of a MPCTC programme for the investigation of colonic masses in symptomatic elderly and frail patients. METHODS: This paper audits a 6-year period of MPCTC in an Australian tertiary referral hospital. A total of 145 patients underwent MPCTC during the study period. RESULTS: There were seven true positives, two false positives and two false negatives. Analysis of this population indicates a sensitivity of 0.78 (95% CI 0.51-1.05), specificity of 0.99 (95% CI 0.97-1.01), positive predictive value (PPV) of 0.78 (95% CI 0.51-1.05) and negative predictive value (NPV) of 0.99 (95% CI 0.97-1.01). These findings are concordant with other published studies. CONCLUSIONS: This audit confirms that minimal preparation CT colonography is a reasonable alternative to OC and CTC in detecting colorectal cancer in symptomatic elderly and frail patients, without the procedural risks inherent in more invasive investigations. For most patients, MPCTC ruled out significant colorectal carcinoma with a high NPV.

Peritoneal Insufflation Facilitates CT-Guided Percutaneous Jejunostomy Replacement.

OBJECTIVE: The purpose of this report was to examine whether peritoneal insufflation can facilitate CT-guided percutaneous jejunostomy replacement. CONCLUSION: Peritoneal insufflation allowed clear differentiation of the adherent jejunum from adjacent bowel, permitting confident direct puncture into the adherent jejunum without the need for jejunopexy anchors.

Intentional right atrial exit for microcatheter infusion of pericardial carbon dioxide or iodinated contrast to facilitate sub-xiphoid access.

OBJECTIVES: We test the safety of transatrial pericardial access using small catheters, infusion of carbon dioxide (CO2 ) or iodinated contrast to facilitate sub-xiphoid access, and catheter withdrawal under full anticoagulation. BACKGROUND: Sub-xiphoid pericardial access is required for electrophysiological and structural heart interventions. If present, an effusion protects the heart from needle injury by separating the myocardium from the pericardium. However, if the pericardium is 'dry' then there is a significant risk of right ventricle or coronary artery laceration caused by the heart beating against the needle tip. Intentional right atrial exit is an alternative pericardial access route, through which contrast media could be infused to separate pericardial layers. METHODS: Transatrial pericardial access was obtained in a total of 30 Yorkshire swine using 4Fr or 2.8Fr catheters. In 16 animals, transatrial catheters were withdrawn under anticoagulation and MRI was performed to monitor for pericardial hemorrhage. In 14 animals, iodinated contrast or CO2 was infused before sub-xiphoid access was obtained. RESULTS: Small effusions (mean 18.5 ml) were observed after 4Fr (1.3 mm outer-diameter) but not after 2.8Fr (0.9 mm outer-diameter) transatrial catheter withdrawal despite full anticoagulation (mean activated clotting time 383 sec), with no hemodynamic compromise. Pericardial CO2 resorbed spontaneously within 15 min. CONCLUSIONS: Intentional transatrial exit into the pericardium using small catheters is safe and permits infusion of CO2 or iodinated contrast to separate pericardial layers and facilitate sub-xiphoid access. This reduces the risk of right ventricular or coronary artery laceration. 2.8Fr transatrial catheter withdrawal does not cause any pericardial hemorrhage, even under full anticoagulation.

Volumetric analysis of colonic distention according to patient position at CT colonography: diagnostic value of the right lateral decubitus series.

OBJECTIVE: The purpose of this study was to compare total colonic gas volume and segmental luminal distention according to patient position on CT colonography (CTC), as well as to determine which two views should constitute the routine protocol. MATERIALS AND METHODS: Volumetric analysis was retrospectively performed on CTC examinations from 146 adults (mean age, 59.2 years; 81 men and 65 women; mean body mass index [BMI], 30.9) for whom supine, prone, and right lateral decubitus series were sequentially obtained using continuous low-pressure CO2 insufflation. Total colonic gas volumes were assessed using a novel automated volumetric tool. In addition, two radiologists scored distention by segment using a 4-point scale (4=optimal; 3=adequate; 2=inadequate; 1=collapsed). RESULTS: Mean (±SD) colonic gas volumes for supine, prone, and decubitus positioning were 1617±567, 1441±505, and 1901±627, respectively (p<0.001). Colonic volume was highest on the right lateral decubitus series in 73.3% (107/146) and lowest in 6.2% (9/146) of cases, whereas the prone series was highest in 0.7% (1/146) and lowest in 73.3% (107/146) of cases. Overall mean segmental reader scores and percentages of inadequate or collapsed for supine, prone, and decubitus positions were 3.48, 3.33, and 3.71 and 10.4%, 12.1%, and 4.2%, respectively (p<0.001). The only mean segmental scores below 3.0 were the sigmoid colon on supine (2.68) and prone (2.58) series, compared with 3.23 on decubitus series (p<0.001). Improvement in distention in both decubitus and supine positions over the prone position increased further with increasing BMI (p<0.001). CONCLUSION: The right lateral decubitus position consistently yields the best colonic distention at CTC and significantly improves evaluation of the sigmoid colon. Prone distention was the worst, particularly as BMI increased. Routine supine and decubitus positioning should be considered for standard CTC protocols, particularly in obese individuals. Automated volumetric analysis provides for rapid objective assessment of colonic distention.

Using pneumo-computerized tomography as a quantitative assessment of result in submucous fibrosis patients treated with surgical release and free flap reconstruction.

OBJECTIVE: This study investigates the efficacy of oral submucous fibrosis release and free flap reconstruction. STUDY DESIGN: Pneumo-computerized tomography (pneumo-CT) was used to evaluate postoperative changes in the buccal vestibular volume during maximum blowing. METHODS: From March 2003 to November 2008, 9 patients underwent 18 microvascular flap reconstructions after oral submucous fibrosis release. The preoperative and postoperative buccal vestibular volumes were determined by capturing the air density in the selected region on CT images, which were composed of 0.75-mm-thick slices that were then summated using analysis software (Biomedical Imaging Resource; Mayo Foundation, Rochester, MN). RESULTS: Postoperative results were measured for a mean follow-up period of 15 months (range, 6-36 mo). There was significant improvement in the interincisal distance from 12.44 (8.35) mm preoperatively to 32.56 (7.322) mm postoperatively (P = 0.000). There was an accompanying significant increase in the buccal vestibular volume from 5.66 (3.92) mL preoperatively to 9.38 (4.96) mL postoperatively on the right side (P = 0.032) and from 6.44 (4.20) mL preoperatively to 9.64 (4.65) mL postoperatively (P = 0.048) on the left side. CONCLUSIONS: Adequate release of the mucosa and resurfacing with a free flap can increase the interincisal distance and improve the maximal buccal vestibular volume. Air-contrast pneumo-CT studies demonstrate an improvement in buccal mucosal elasticity.

Safety of percutaneous endoscopic gastrostomy in high-risk patients.

Percutaneous endoscopic gastrostomy (PEG) is a minimally invasive procedure. However, failure to transilluminate the anterior wall of the stomach or visualize the indentation of the physician's finger represents the most frequent obstacles encountered by the endoscopist in safely completing PEG tube placement. We described several methods to safely assess PEG placement in high-risk patients. An abdominal plain film after gastric insufflated with 500 mL of air is obtained before PEG in patients. The body of the stomach near the angularis, equidistant from the greater and lesser curves, was defined as the optimal gastric puncture point. The location of the puncture points varied greatly, being situated over the right upper quadrant in 31% of patients, left upper in 59%, left lower in 5%, and right lower quadrant in 5% of patients. If there is any question of safe puncture site selection, safe track technique can be used to provide the information of depth and angle of the puncture tract. Computed tomography can provide detailed anatomy and orientation along the PEG tube and show detailed anatomical images along the PEG tract. Computed tomography-guided PEG tube placement is used when there is difficulty either insufflating the stomach, or the patients had previous surgery, or anatomical problems. Full assessment of the position of the stomach and adjacent organs prior to gastric puncture may help minimize the risk for potential complications and provide safety for the high-risk patients.

[Carbon dioxide angiography in EVAR: basic principles, indications and limitations]. / Die CO2-Angiografie bei EVAR-Prozeduren: Grundlagen, Indikationen und Grenzen.

Compared to open surgery, endovascular aneurysm repair has shown superior results in terms of morbidity and mortality. Therefore the 2011 published Practical Guidelines for Abdominal Aortic Aneurysm Repair (EVAR) demand an individual evaluation of every patient concerning an EVAR solution. To reduce the risk of contrast-associated complications such as severe allergic reactions hyperthyroidism or contrast-induced nephropathy with permanent loss of renal function, the use of carbon dioxide should be considered for every case. The imaging software solutions are part of the modern angiography technique and the imaging quality of CO2 angiography is equivalent or even better as compared to conventional angiography when the patient is appropriately prepared and positioned.

The peroral pneumocolon revisited: a valuable fluoroscopic and CT technique for ileocecal evaluation.

The peroral pneumocolon represents a time-honored but somewhat forgotten and underutilized technique for improved ileocecal evaluation at small bowel fluoroscopy. The peroral pneumocolon entails fluoroscopically guided gaseous insufflation per rectum following the arrival of barium at the cecum at conventional small bowel follow-through examination. In most cases, high-quality double contrast evaluation of the terminal ileum can be achieved, often superior to enteroclysis examination for this critical location. The peroral pneumocolon improves diagnostic confidence, including assessment of disease activity, and may result in a reversal of the diagnostic impression. This simple procedure will be discussed and a spectrum of fluoroscopic findings with CT and endoscopic correlation will be provided to demonstrate the added yield of this technique in the evaluation of known or suspected Crohn's disease. Application of the pneumocolon technique to CT for combined small and large bowel evaluation ("CT coloenterography") will also be discussed, which represents an attractive new option for investigating inflammatory bowel disease and other bowel-related conditions. Through the use of automated low-pressure carbon dioxide delivery per rectum, supplemented by IV glucagon for relaxation of the ileocecal valve, a CT-based pneumocolon examination may prove to be a useful hybrid technique for bowel evaluation in the future.

A randomized, controlled, double-blind trial of air insufflation versus carbon dioxide insufflation during ERCP.

BACKGROUND: Visualization during GI endoscopy requires distention of the bowel lumen. Carbon dioxide (CO(2)) insufflation decreases postprocedure abdominal discomfort and distension after colonoscopy, but there have been few published studies on its use in ERCP. OBJECTIVE: To assess the safety and efficacy of CO(2) insufflation during ERCP. DESIGN: Double-blind, controlled, randomized trial. SETTING: Tertiary-care referral center. PATIENTS: This study involved consecutive patients referred for ERCP, excluding those with known CO(2) retention or with chronic use of opiate medications. INTERVENTION: Insufflation of CO(2) versus insufflation of air. MAIN OUTCOME MEASUREMENTS: Primary outcomes were abdominal pain assessed on a visual analogue scale and abdominal distension. Secondary outcomes included transcutaneous CO(2) levels (pCO(2)) and procedural complications. RESULTS: We analyzed 74 patients, 38 in the air group and 36 in the CO(2) group. Pain scores were similar in both groups 1-hour postprocedure (16 vs 11 mm in the CO(2) and air groups, respectively; P = .29) as well as over the subsequent 24 hours. There were also no significant differences between groups in abdominal distension or pCO(2) levels. There were 13 patients with complications in the air group and 5 in the CO(2) group (P = .04; nominal significance removed by Bonferroni correction), although most complications were minor in nature. LIMITATIONS: Single-center study. CONCLUSION: The use of CO(2) for insufflation during ERCP was safe in a tertiary-care referral population. However, use of CO(2) during ERCP did not lead to decreased postprocedural pain or less abdominal distension, so its role in this procedure remains in question. NCT00685386.

Esophageal cancer: pneumo-64-MDCT.

BACKGROUND: Pre-surgical characterization and staging of esophageal cancer with only one imaging method could be useful since gastric invasion determines the scope of resection and the kind of surgery to be performed. Our aim is to demonstrate the usefulness of Pneumo-64-MDCT (PnCT64) in the presurgical characterization of esophageal neoplasms in correlation with surgical findings. MATERIALS AND METHODS: A total of 50 patients with diagnosis of esophageal neoplasm were prospectively studied. A 14 French Foley catheter was used transorally in all patients. Air was instilled through the catheter to achieve esophageal distension. A 64-row MDCT scan was performed and the tumor was characterized according to scope, shape and anatomic location by using multiplanar 3D reconstructions and virtual endoscopy. Wall infiltration and presence of adenopathies were analyzed. RESULTS: Adequate gastroesophageal distension was achieved in all patients. In 44/50 patients, wall thickening was observed, and in 34/50 regional adenopathies were found. In 29/50 patients the lesion was found in the lower third and in the gastroesophageal junction. The surgical correlation for wall infiltration was 85.7%. CONCLUSIONS: PnCT64 proved to be useful and safe for identification of esophageal wall thickening and presurgical characterization. Optimal distension allowed definition of both upper and lower borders of the tumors located in the gastroesophageal junction, of utmost importance to determine the surgical approach.

An interactive teaching device simulating intussusception reduction.

Intussusception is relatively uncommon, occurring in 0.5 to 2.3 cases per 1,000 live births in the USA. Radiology residents, therefore, have few opportunities to participate in intussusception reduction during training, and practicing radiologists encounter it infrequently. Training is essential, as successful reduction avoids surgery. The judgment involved in reducing an intussusception is best gained with experience. We developed a training device that simulates fluoroscopic intussusception reduction with air. The device consists of a doll that contains a cylinder with similar stress and strain characteristics to the human colon. The trainee pumps air into the cylinder through a rectal tube using a standard hand-held air reduction pump. A sensor measures the pressure within the chamber and transmits readings to a computer, which displays images from actual intussusception reductions based on the pressure maintained within the device. A random component in the software gives the user a new experience each time and models uncertainties in the actual reduction process, including perforation. This intussusception reduction simulator can enhance resident education, giving residents the opportunity to practice this technique before employing it on a real patient. The simulator can also help practicing radiologists become more comfortable with intussusception air reduction.

[Usefulness of Pneumo-64-MDCT in the presurgical evaluation of esophageal cancer]. / Utilidad de la neumotomografia multislice 64 en la evaluación prequirúrgica del cáncer esofágico.

BACKGROUND: Pre-surgical characterization and staging of esophageal and esophagogastric union cancer with only one imaging method could be useful for the therapeutic strategy. OBJECTIVE: 1) To evaluate the sensitivity of Pneumo-64-MSCT (PnCT64) in the diagnosis of esophageal-cardial wall thickening in correlation with anatomopathological and postsurgical findings. 2) To evaluate the usefulness of gastric distension in the presurgical planning of esophageal cancer, especially those located in the gastroesophageal junction. METHODS: Twenty-four patients with endoscopic diagnosis of esophageal and cardial cancer were prospectively studied with PnCT64 before surgery. CT's were performed with a 64 row CT scanner and in order to achieve esophageal distension, CO2 was instilled with an automated insufflator through a Foley catheter. Mural thickening was evaluated as well as its scope, shape and anatomic location by using different type of reconstructions. PnCT64 findings were correlated with anatomopathological staging. RESULTS: In 21 patients an asymmetric wall thickening was observed with a sensitivity of 86.4% in correlation with anatomopathological findings. Adequate gastroesophageal distension defining the limits of the lesions was achieved in all patients. CONCLUSION: PnCT64 showed high sensitivity in the diagnosis of esophageal and cardial thickening. Gastric distension proved to be useful for the presurgical evaluation defining both upper and lower borders of the tumors located in the gastroesophageal junction.

[Diagnostic criteria for surgical correction of exudative otitis media in children].

A total of 118 children with exudative otitis media were available for observation in this study. Pneumatization of the mastoid process was evaluated by the roentgenoplanimetric technique. A large fraction of patients (48%) with acute exudatived otitis media showed pneumatic type of pneumatization whereas sclerotic pneumatization predominated in children with chronic exudative otitis media (68%). Retractions significantly more frequently developed in ears with the sclerotic type of pneumatization of the mastoid process (91%) than in case of pneumatic pneumatization. Based on these data, the children were divided into two groups, one comprising 25 patients with acute exudative otitis, the other 35 ones with recurrent disease. It is concluded that children with the symptomocomplex characterized by low level of pneumatization of the mastoid process, conductive or mixed hearing loss with a bone-air interval of 30-50 dB, and type B tympanogram are in need of early surgical intervention.

Cholangitis prevention in endoscopic Klatskin tumor palliation: air cholangiography technique.

INTRODUCTION: Endoscopic biliary drainage is the treatment of choice for inoperable hilar cholangiocarcinoma (so-called Klatskin tumor). Cholangitis is the main complication post-endoscopic retrograde cholangiopancreatography (ERCP) in Klatskin patients, specially when medium contrast is injected into biliary tree that could not be subsequently drained. Bacterial cholangitis is the principal cause of mortality in these patients. The aim of this study is to analyze cholangitis rate resulting from the use of air versus iodine contrast to obtain cholangiography during ERCP. METHODS: In 9 years, 188 inoperable Klatskin patients were recruited and divided into two groups: iodine (A) or air (B) contrast cholangiography, respectively. We used air or iodine contrast to obtain cholangiography before hilar stricture stenting. We retrospectively compared these data in both groups. RESULTS: The group B had a significant lower rate of cholangitis than group A in Bismuth type II (p < 0.05), in Bismuth type III (p < 0.05), and in the Bismuth type IV population (p < 0.05). CONCLUSION: The air contrast cholangiography is a safe and effective method, and it appears justified as a routine procedure to prevent or reduce the risk of post-ERCP cholangitis, specially in Klatskin patients (p < 0.005).

Potential extraperitoneal space continuous with the peri-intestinal space: CT evidence and anatomical evaluation in patients with pneumatosis intestinalis without intestinal ischemia.

PURPOSE: Extraperitoneal spaces, such as the mesenteric space and the retroperitoneal space, can serve as areas that enable a reduction in the pressure exerted by extraperitoneal fluid collection and infiltrating diseases. In clinical practice, understanding the existence of these decompression spaces (or pathways) is very important for making accurate diagnoses. Here, we evaluated potential anatomical extraperitoneal spaces based on the extraluminal gas distribution in patients with pneumatosis intestinalis without intestinal ischemia. METHODS: The computed tomography scans of ten patients with pneumatosis intestinalis without intestinal ischemia were reviewed, and the anatomic location of the extraluminal gas distribution was investigated. RESULTS: Four patients were diagnosed as having pneumatosis intestinalis of the small intestine and six were diagnosed as having pneumatosis intestinalis of the large intestine. Mesenteric pneumatosis was observed in nine (90%) of the ten patients. The potential anatomical extraperitoneal spaces (or decompression pathways) were classified as follows: mesenteric (n = 3), retroperitoneal (n = 4), and direct (n = 5). CONCLUSIONS: The distributions of the extraluminal gas were classified into three categories, and each location may characterize a different decompression pathway. The existence of a potential extraperitoneal space continuous with the peri-intestinal space was confirmed in living subjects.

CT colonography for incomplete or contraindicated optical colonoscopy in older patients.

OBJECTIVE: Our purpose was to assess the performance of CT colonography (CTC) in patients older than 60 years who were referred because colonoscopy was contraindicated or incomplete. MATERIALS AND METHODS: Over a 2-year period, 61 patients underwent CTC at our institution, 42 of whom (26 women, 16 men) were 60 years old or older (range, 60-87 years; mean age, 71 years). After 24-48 hours of ingesting only clear liquids and after colonic cleansing, fecal tagging, and automated CO2 insufflation, patients were scanned using a 16-MDCT scanner. Images were obtained with the patient in the supine and prone positions and as needed in the right or left decubitus position. Axial 2D and 3D endoluminal views were evaluated on a dedicated workstation. RESULTS: Contraindications to colonoscopy in 12 (29%) of the 42 patients were as follows: anticoagulation (n = 8), increased anesthesia risk (n = 3), and poor tolerance for colonoscopy preparation (n = 1). Incomplete colonoscopy in the other 30 patients (71%) was due to diverticular disease (n = 10), colonic redundancy (n = 10), adhesions (n = 3), residual colonic content (n = 3), sigmoid stricture (n = 1), ventral hernia (n = 1), and unknown cause (n =2). No complications were observed. Optimal distention of the entire colon was achieved in 38 patients (90%). Thirty-nine (93%) of the 42 patients had abnormal findings: diverticular disease (n = 25), one or more polyps (n = 22), a mass lesion (n = 1), a lipoma (n = 1), and inflammatory stricture (n = 1). Extracolonic findings potentially requiring further evaluation or treatment were observed in 26 patients (62%). CONCLUSION: CTC using CO2 insufflation was well tolerated and successful in imaging the entire colon in most of the 42 patients, despite the presence of sigmoid diverticular disease or colonic redundancy.