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INTRODUCTION Unintentional weight loss is an important clinical problem. The role of CT is not firmly established in the workup of these patients. The aim of this study is to determine the diagnostic yield of CT Thorax, Abdomen and Pelvis (CT TAP) in patients with unexplained weight loss and to determine whether clinical or laboratory variables are associated with positive CT findings. METHODS A retrospective review was performed of CT TAP examinations over 12 months with weight loss as an indication. Patients' electronic records and radiology reports were reviewed. Clinical and laboratory variables were assessed for correlation with positive findings on CT. RESULTS 461 CT TAP studies with weight loss as the primary indication were identified. 124 were excluded; 82 due to a recent history of malignancy, 41 because CT TAP was used for staging of a new malignancy and one study was incomplete. This left 337 eligible examinations. 217 studies had findings of no clinical relevance, 50 studies were normal, 40 studies identified a possible cause of weight loss and 30 studies identified a definite cause. Of the 40 where a possible cause was identified, further work up led to a diagnosis which explained the weight loss in 13 patients. The diagnostic yield of CT TAP was 12.8%. Age, abdominal symptoms, degree of weight loss, anaemia, tumour markers and LDH did not significantly correlate with positive findings on CT. CONCLUSION CT TAP is a helpful investigation in patients with unexplained weight loss with a diagnostic yield of 12.8%.

Background. The role of kidney volume measurement in predicting the donor and recipient kidney function is not clear. Methods. We measured kidney volume bilaterally in living kidney donors using CT angiography and assessed the association with the donor remaining kidney and recipient kidney (donated kidney) function at 1 year after kidney transplantation. Donor volume was categorized into tertiles based on lowest, middle, and highest volume. Results. There were 166 living donor and recipient pairs. The mean donor age was 44.8 years (SD ± 10.8), and donor mean BMI was 25.5 (SD ± 2.9). The recipients of living donor kidneys were 64% male and had a mean age of 43.5 years (SD ± 13.3). Six percent of patients experienced an episode of cellular rejection and were maintained on dialysis for a mean of 18 months (13–32) prior to transplant. Kidney volume was divided into tertiles based on lowest, middle, and highest volume. Kidney volume median (range) in tertiles 1, 2, and 3 was 124 (89–135 ml), 155 (136–164 ml), and 184 (165–240 ml) with donor eGFR ml/min (adjusted for body surface area expressed as ml/min/1.73 m2) at the time of donation in each tertile, 109 (93–129), 110 (92–132), and 101 ml/min (84–117). The median (IQR) eGFR in tertiles 1 to 3 in kidney recipients at 1 year after donation was 54 (44–67), 62 (50–75), and 63 ml/min (58–79), respectively. The median (IQR) eGFR in tertiles 1 to 3 in the remaining kidney of donors at 1 year after donation was 59 (53–66), 65 (57–72), and 65 ml/min (56–73), respectively. Conclusion. Bigger kidney volume was associated with better eGFR at 1 year after transplant in the recipient and marginally in the donor remaining kidney.

OBJECTIVE Evaluate the efficacy and quality of life associated with conservative treatment of acute uncomplicated appendicitis. SUMMARY BACKGROUND DATA Conservative management with antibiotics only has emerged as a potential treatment option for acute uncomplicated appendicitis. However the reported failure rates are highly variable and there is a paucity of data in relation to quality of life. METHODS Symptomatic patients with radiological evidence of acute, uncomplicated appendicitis were randomized to either intravenous antibiotics only or undergo appendectomy. RESULTS One hundred eighty-six patients underwent randomization. In the antibiotic-only group, 23 patients (25.3%) experienced a recurrence within 1 year following randomization. There was a significantly better EQ-VAS quality of life score in the surgery group compared with the antibiotic-only group at 3 months (94.3 vs 91.0, P < 0.001) and 12 months postintervention (94.5 vs 90.4, P < 0.001). The EQ-5D-3L quality-of-life score was significantly higher in the surgery group indicating a better quality of life (0.976 vs 0.888, P < 0.001). The accumulated 12-month sickness days was 3.6 days shorter for the antibiotics only group (5.3 vs 8.9 days; P < 0.01). The mean length of stay in both groups was not significantly different (2.3 vs 2.8 days, P = 0.13). The mean total cost in the surgery group was significantly higher than antibiotics only group (€4,816 vs €3,077, P < 0.001). CONCLUSIONS Patients with acute, uncomplicated appendicitis treated with antibiotics only experience high recurrence rates and an inferior quality of life. Surgery should remain the mainstay of treatment for this commonly encountered acute surgical condition.

Main recommendations1. ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia. Strong recommendation, high quality evidence. ESGE/ESGAR do not recommend barium enema in this setting. Strong recommendation, high quality evidence.2. ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors. Strong recommendation, low quality evidence. ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete. Weak recommendation, low quality evidence.3. When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms. Strong recommendation, high quality evidence. Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation. Very low quality evidence. ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms. Strong recommendation, high quality evidence. In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms. Weak recommendation, low quality evidence.4. Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors. Strong recommendation, high quality evidence. ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer. Weak recommendation, low quality evidence.5. ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs. Strong recommendation, moderate quality evidence. ESGE/ESGAR also suggest the use of CCE in this setting based on availability. Weak recommendation, moderate quality evidence.6. ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in this setting. Very low quality evidence.7. ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in post-polypectomy surveillance. Very low quality evidence.8. ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation. Strong recommendation, low quality evidence. 9. ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp >= 6 mm detected at CTC or CCE. Follow-up CTC may be clinically considered for 6-9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia. Strong recommendation, moderate quality evidence.Source and scopeThis is an update of the 2014-15 Guideline of the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). It addresses the clinical indications for the use of imaging alternatives to standard colonoscopy. A targeted literature search was performed to evaluate the evidence supporting the use of computed tomographic colonography (CTC) or colon capsule endoscopy (CCE). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence.

IntroductionBiologic and small-molecule therapies have revolutionised the treatment of moderate-to-severe inflammatory bowel disease (IBD). A significant proportion of patients experience early or delayed treatment failure. Patients with IBD with greater visceral obesity are less likely to respond to biologics. Sarcopenia has been identified as a predictor of disease severity and need for rescue therapy in acute severe ulcerative colitis. The aim of this study is to assess the feasibility of a physician-derived exercise programme in patients with IBD commencing biologic or small-molecule therapy in addition to the effect on physical fitness, body composition and objective measures of quality of life, fatigue scores and disease activity.Methods and analysisThis is a randomised controlled feasibility study comparing the effects of a physician-derived exercise programme and standard medical care (biologic/small-molecule therapy) with standard care alone in patients with moderate to severe IBD. Patients with IBD in the intervention group will undergo a structured exercise programme for 20 weeks. Both IBD groups will carry out body composition, disease activity and quality-of-life assessments at baseline, week 12 and week 26. The primary objective is to assess the feasibility of the physician-derived exercise programme in patients with IBD commencing disease-modifying therapies. Secondary endpoints include a change in cardiorespiratory fitness, disease activity/inflammation, fatigue, health-related quality of life outcomes and body composition between the two IBD groups. Exploratory endpoints include validation of anterior thigh ultrasound for sarcopenia screening, assessment of proinflammatory cytokines and markers of immunometabolism.Ethics and disseminationThis study has received ethical approval from the Beaumont Hospital Ethics committee on 22 October 2021 (reference number 21/21). Data generated or analysed during this study will be published as an article and supplementary appendix in relevant medical journals. The data will also be presented at national and international conferences.Trial registration numberNCT05174754.

INTRODUCTION There are few existing severity scoring systems in the literature, and no formally widely accepted chest X-ray template for reporting COVID-19 infection. We aimed to modify the chest X-ray COVID-19 severity scoring system from the Brixia scoring system with placement of more emphasis on consolidation and to assess if the scoring tool could help predict intubation. METHODS A severity chest X-ray scoring system was modified from the Brixia scoring system. PCR positive COVID-19 positive patient's chest X-rays admitted to our hospital over 3 months were reviewed and correlated with; non-invasive ventilation, intubation and death. An analysis was performed using a receiver operating curve to predict intubation from all admission chest X-rays. RESULTS The median score of all 325 admission chest X-rays was 3 (Interquartile range (IQR) 0-6.5). The median score of admission chest X-rays of those who did not require ICU admission and survived was 1.5 (IQR 0-5); and 9 (IQR 4.75-12) was median admission score of those requiring intubation. The median scores of the pre-intubation ICU chest X-rays was 11.5 (IQR 9-14.125), this increased from a median admission chest X-ray score for this group of 9 (P-value

Magnetic resonance imaging provides detailed visualisation, identification and extent assessment of many anal disorders. While many studies are performed in the evaluation of malignant processes such as anorectal carcinoma, the primary focus of this pictorial review is benign lesions, which involve the anal canal and perianal spaces. This pictorial review will illustrate the MRI appearances of a variety of benign conditions, which predominantly affect the anal canal, including abscess, fistulae, lipomas, developmental cysts and inflammatory conditions. MRI aids in the identification and characterisation of these abnormalities, of coexisting complications and differentiation from other perineal abnormalities. This pictorial review highlights the spectrum of non-malignant processes involving the perianal region.

Colorectal cancer accounts for 11% of all cancer-related deaths in Ireland. With the aim of diagnosing these cancers at an earlier stage, and detecting premalignant lesions, the National Screening Service (NSS) offered a fecal immunochemical test (FIT) to all individuals aged 60 to 69. All individuals in the age range were contacted by post and invited to participate in the programme. Those with a positive FIT result were offered a colonoscopy in an internationally accredited unit. From an eligible population of 488,628, 196,238 individuals participated giving an uptake of 40.2%. Commencing at a FIT threshold of 20 μg Hg/g feces, the positivity rate was 8.6%, which overwhelmed colonoscopy capacity and, thus, the threshold was increased to 45 μg, resulting in an overall 5% positivity rate. A total of 520 individuals had cancer detected (68.3% stage I or II), of which 104 were removed endoscopically (pT1s). Adenomas were present in 54.2% of all colonoscopies, 17.4% deemed high risk. Despite a lower uptake, males were twice as likely to have colorectal cancers as females and had a 59% increased rate of high-risk adenomas diagnosed. Challenges facing the programme include increasing participation, especially among males, and increasing colonoscopy capacity. The ability to alter the sensitivity of FIT to match colonoscopy capacity is a valuable option for such a programme as it ensures that the maximum public health benefit can be achieved within available resources.

Appendiceal tumours are uncommon neoplasms of the gastrointestinal tract. An understanding of the imaging appearances facilitates an accurate radiological description, which guides surgical and oncological management. In this study, a retrospective review of the CT imaging and histopathology of all cases of appendiceal tumours discussed at the oncology multidisciplinary meetings in a single centre, over an 8-year period (2012-2019) is performed. The array and incidence of both common and rare pathologies are investigated, and important characteristic imaging findings for radiologists to recognize are highlighted.

Objectives To develop imaging guidelines for patients with fistula-in-ano and other causes of anal sepsis. Methods An expert group of 13 members of the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) used a modified Delphi process to vote on a series of consensus statements relating to the imaging of patients with potential anal sepsis. Participants first completed a questionnaire to gather practice information and to help frame the statements posed. Results In the first round of voting, the expert group scored 51 statements of which 45 (88%) achieved immediate consensus. The remaining 6 statements were redrafted following input from the expert group and consensus achieved for all during a second round of voting, including an additional statement drafted. No statement was rejected due to a lack of consensus. After redrafting to improve clarity, 53 individual statements were presented. Conclusion These expert consensus statements can be used to guide appropriate indication, acquisition, interpretation and reporting of medical imaging for patients with potential fistula-in-ano and other causes of anal sepsis. Key Points • Medical imaging, notably magnetic resonance imaging, is used widely for the diagnosis and monitoring of fistula-in-ano and other causes of anal and perianal sepsis. • While the indexed medical literature is clear that diagnostic accuracy is potentially excellent, this depends on competent image acquisition and interpretation. • In order to facilitate this, the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) has produced expert consensus guidelines regarding the imaging of fistula-in-ano and related conditions.

BACKGROUND Prospective renal donors are a select population of healthy individuals who have been thoroughly screened for significant comorbidities before they undergo multi-detector computed tomography angiography and urography (MDCT). PURPOSE The aim of this study is to describe the anatomy of potential living renal donor subjects using MDCT over a 2-year period. The primary objective is to identify the renal arterial anatomy variations, with a secondary objective of identifying venous and collecting system/ureteric variations. MATERIALS AND METHODS A prospective study was performed of prospective living kidney transplant donors at a national kidney transplant centre. Study inclusion criteria were all potential kidney donors who underwent MDCT during the living-donor assessment process over a 2-year period. RESULTS Our cohort included 160 potential living donors who had MDCT; mean age was 45.6 years (range, 21-71). Two renal arteries were identified on the left in 40 subjects (25%) and on the right in 42 subjects (26.3%). A total of 3 or more renal arteries were identified on the left in 7 subjects (4.4%) and on the right in 7 subjects (4.4%). On the left, the distances between multiple arteries ranged from 1 mm to 43 mm, and on the right, they were 1 mm to 84 mm. CONCLUSIONS Conventionally described anatomy was only seen on the left side in 70.6% and 69.4% on the right side of subjects. Single renal arteries are seen in 54.4% showing that conventional anatomy has a relatively low incidence.

Same-day CT colonography (CTC) following incomplete optical colonoscopy allows patients to avoid both a delayed diagnosis and the need for repeat bowel preparation. The aim of our study is to establish the diagnostic quality of same-day CT colonography following an incomplete optical colonoscopy.We performed a retrospective review of patients undergoing same-day CT colonography following an incomplete colonoscopy at our center between July 2015 and December 2017 (N = 245). We divided the large bowel into thirteen subsegments in each patient. Using a semiquantitative scoring system, the quality of bowel preparation, adequacy of fecal tagging, and luminal distension were assessed in each subsegment on all views performed. A combined score for each subsection was obtained.Ninety-nine percent of studies did not require a repeat CTC or optical colonoscopy. Median values for bowel preparation and fecal tagging were satisfactory across the bowel segments for the cohort and luminal distension was acceptable in all but three patients.Same-day CTC should be considered in centers with capacity, following an incomplete optical colonoscopy. Same-day completion CTCs are of high diagnostic quality and this approach allows patients to avoid repeat bowel cleansing or a delayed diagnosis.• Same-day CT colonography is a high-quality examination that can be performed following incomplete optical colonoscopy. • Same-day CT colonography should be considered for patients with incomplete optical colonoscopy in centers with the capacity to offer this service. • Same-day CTC can avoid a delay in diagnosis and avoids repeat bowel preparation.

Aims: Both fluoroscopic water-soluble contrast swallow (FWSCS) and CT water-soluble contrast swallow (CTWSCS) are widely performed as a routine in the post-esophagectomy patient to assess for anastomotic leak. Several prospective studies have compared FWSCS and CTWSCS; however, no synthesis of the data exists. Materials and Methods: Systematic review and meta-analysis of diagnostic test accuracy studies comparing FWSCS and CTWSCS in the adult patient following esophagectomy for malignancy was performed in accordance with PRISMA guidelines. Results: Three diagnostic test accuracy studies met the inclusion criteria, directly comparing FWSCS and CTWSCS in 185 patients. FWSCS demonstrated high specificity (98%), but low sensitivity (64%). CTWSCS can be categorized as normal, mediastinal gas without contrast leak, or leakage of oral contrast. Visible leakage of oral contrast demonstrated high specificity (98%) but low sensitivity (56%). The presence of mediastinal gas increased sensitivity (84%), but reduced specificity (85%). The higher sensitivity of CTWSCS over FWSCS failed to reach significance (P = 0.125). Conclusion: CTWSCS shares the high specificity of FWSCS. Its higher sensitivity increases its utility as a rule-out test in the postoperative period. Additional factors that may influence decision-making are described.

Routine low dose non-contrast CT of the abdomen and pelvis has been suggested prior to same day completion CT colonography (CTC) to assess for occult perforation at preceding incomplete colonoscopy, before further gaseous insufflation at CTC. The aim of our study is to examine the incidence of clinically significant perforation at low dose CT. We also examine the benefits of low dose pre-scan in assessing adequacy of bowel preparation and identifying any other relevant contraindications to CT colonography. We conducted a retrospective review of all low dose non-contrast CTs performed following failed colonoscopies over a 4-year period (n = 392). We also assessed the adequacy of bowel preparation on a scale of 1–5, in order of increasingly adequate preparation. Incidentally noted bowel pathology and contraindications to CT colonography were also recorded. No perforation was identified either prospectively or in the course of our retrospective review. However, 15 patients (3.8%) were found to have potential contraindications to CT colonography, including: acute diverticulitis, acute colitis, and poor bowel preparation. Overall, the bowel preparation was felt to be adequate (≥ 3) in 86% percent of patients. Two patients (0.5%) identified prospectively had their CT colonography postponed due to poor bowel preparation.

Computed tomographic (CT) colonography comprises thin-section CT scanning of the prepared, gas-distended colon, acquired in more than one patient position. The test is widely available internationally and is highly sensitive for colorectal cancer, including significant polyps and early colorectal cancers (SPECC). In this article, we will discuss the basic technique of CT colonography, its diagnostic performance, the challenge of detecting serrated polyps and handling of diminutive polyps. Since CT colonography permits a detailed assessment of polyp morphology, radiologists must communicate their descriptions of the CT appearances of larger polyps accurately and using widely-accepted terminology. This allows services to plan their resection strategy for these larger lesions in timely fashion and ensure availability of appropriate staff and equipment for that patient. Close collaboration between all members of the multi-disciplinary team will ensure that all patients have access to high-quality colonic imaging services.

OBJECTIVES Prospective renal donors are a select population of healthy individuals who have been thoroughly screened for significant comorbidities before they undergo multidetector computed tomography. Our aim was to determine the prevalence of incidental findings on preoperative multidetector computed tomography in a healthy cohort of potential living donors for kidney transplant. MATERIALS AND METHODS A prospective study was performed of prospective living kidney transplant donors at a national kidney transplant center. Study inclusion criteria were all potential kidney donors who underwent multidetector computed tomography during the living-donor assessment process over a 5-year period (January 2012 to 2017). RESULTS Our cohort included 375 potential living donors who had multidetector computed tomography; mean age was 44.33 years (range, 21-71.5 y). In total, there were 228 incidental findings identified in 158 individuals. Of the 375 potential donors, 193 (51%) proceeded to living donor nephrectomy. On multidetector computed tomography, 97 incidental findings were identified in the donor cohort versus 131 in the cohort that did not proceed to donation. Bosniak 1 renal cysts were the most common incidental finding (n = 46) followed by liver cysts < 1.5 cm (n = 42) and urinary tract calculi (n = 21). There was 1 incidentally detected pathologically proven malignancy. CONCLUSIONS A variety of incidentally detected lesions of moderate to high importance were detected in this healthy donor cohort. Individuals undergoing assessment with multidetector computed tomography for living donor nephrectomy should be counseled on medical, financial, and psychological implications of incidentally detected lesions during the kidney transplant evaluation process.

Encapsulating peritoneal sclerosis (EPS) is arguably the most serious complication of chronic peritoneal dialysis (PD) therapy with extremely high mortality rates. We aimed to establish the rates of EPS and factors associated with its development in a single center.We retrospectively reviewed the records of all our PD patients from 1 January 1989 until 31 December 2008. All suspected cases were confirmed at laparotomy. Multifactorial models adjusted for potentially confounding variables such as age and sex.Eleven cases of EPS were identified giving a prevalence rate of 1.98%. Median duration on PD was substantially longer in affected versus unaffected patients (42.5 months versus 13.8 months; p = 0.0002). EPS patients had experienced a mean of 3.54 previous cases of peritonitis (1 infection per year versus 0.71 per year in unaffected patients; p = 0.075). Six patients died (54.5%) due to intra-abdominal sepsis including all five who presented with small bowel obstruction. Three patients had an omentectomy and adhesiolysis performed with a successful outcome.Our study reinforces the link between duration on PD and EPS. While mortality was high in our cohort, emerging surgical techniques demonstrate a favorable outcome that can be achieved even in severely affected cases.

Purpose: To retrospectively evaluate the positive predictive value (PPV) of computed tomographic (CT) colonography performed in patients who were referred for further examination after incomplete colonoscopy. Materials and Methods: This HIPAA-compliant retrospective study was approved by the institutional review board; informed consent was waived. We identified 546 consecutive patients (mean age, 64.1 years; 401 [73.4%] women) who underwent CT colonography after incomplete colonoscopy between November 1999 and December 2002. A retrospective chart review was performed if CT colonography depicted endoscopically nonvisualized lesions 6 mm or greater in diameter. Repeat colonoscopy rate, endoluminal findings, and PPV of CT colonography were determined. Subsequent colonoscopic findings were used as the reference standard. Results: In 72 (13.2%) patients, CT colonography depicted 88 endoscopically nonvisualized lesions 6 mm or greater. Of 11 patients reported to have 12 masses (≥20 mm), at subsequent colonoscop...

Computed tomographic (CT) colonography continues to evolve rapidly. Advances in scanning and display technologies, encouraging performance data, and increased utilization necessitate clarification and standardization of results reporting in CT colonography. There are several reasons for this. First and most important, standardized reporting can better assist patients and referring physicians in making management decisions on the basis of the results of CT colonography. The precedent of the mammography Breast Imaging Reporting and Data System, or BI-RADS, schema is a strong incentive to provide a similar structure for CT colonography. Second, as more examinations are performed, the likelihood increases that radiologists interpreting results of a CT colonography examination performed at one center will require comparison to examination results and reports generated at other sites. As has been seen with mammography, a common set of terms facilitates this kind of assessment (1). Third, as utilization of CT colonography increases, our colleagues in other medical specialties, the various third-party payers, and the general public will insist on larger-scale evaluations of examination performance, examination quality, patient outcome, and cost. Here again, a common approach to interpretation will assist us in meeting these demands. Finally, a common scheme for reporting facilitates structured reporting. The purpose of this communication is to facilitate clear and consistent communication of CT colonography results. The authors—an ad hoc group of investigators active in the area of CT colonography—have collaborated to develop a reporting scheme that is coupled to recommendations for follow-up. Our group, the Working Group on Virtual Colonoscopy, includes members of the American College of Radiology Colon Cancer Committee. On the basis of our collective experience and a review of the relevant literature, we present a practical guide to the interpretation of CT colonography results: the CT Colonography Reporting and Data System, or “C-RADS.” Future multidisciplinary collaboration and longitudinal data may lead to a refinement of the terms and concepts we present here; our effort is a starting point in which we attempt to address the needs of current practice. Adequate training and rigorous quality control of examination performance are essential elements for maximizing the potential of CT colonography; however, these related topics will not be discussed here. Instead, we will focus on the interpretation and follow-up of CT colonography results in three parts: first, a description of terms useful for reporting the size, morphologic features, and location of polyps and masses; second, a description of a classification scheme for colonic lesions and suggestions for follow-up; Published online 10.1148/radiol.2361041926 Radiology 2005; 236:3–9 1 From the Division of Abdominal Imaging and Intervention, Department of Radiology/ White 270, Massachusetts General Hospital, Boston, MA 02114 (M.E.Z.). The complete list of author affiliations is at the end of this article. Received November 12, 2004; accepted November 15. Address correspondence to M.E.Z. (e-mail: mzalis@partners.org).

Increased utilization of cross-sectional imaging has resulted in increased detection of incidental renal tumors. The noninvasive characterization of renal tissue has important implications for the diagnosis of renal malignancies and treatment monitoring. Recently, multiple breath-hold averaged proton magnetic resonance spectroscopy (1H-MRS) performed at high field has enabled the use of this noninvasive metabolic profiling technique for the investigation of the abdomen. Multiple breath-hold averaged1H-MRS at high field (3T) was obtained in the kidneys of 10 healthy volunteers and in renal cell carcinoma tumors of 14 patients. The spectra of normal kidneys showed four main groups of resonances: 1) at 5.4–5.6 ppm, attributed to C6 of cholesterol and the unsaturated parts of the olefinic region of fatty acids; 2) at 4.7 ppm, attributed to the residual water signal; 3) at 3.2 ppm, attributed to trimethylamine moiety of choline metabolites; and 4) at 1.3 and 0.9 ppm, attributed to the methylenes and terminal methyls of lipids. The ratio of the signal at 5.4 ppm to that of 1.3 ppm was 19-fold lower in renal cell carcinomas than in healthy kidneys, tied P = 0.0003 Mann-Whitney U-test, suggesting a decrease in both free cholesterol and the degree of unsaturation of fatty acids in the malignant tissue. This metabolic shift is in agreement with previous ex vivo studies of human renal cell carcinoma. The ability to detect renal metabolic shifts noninvasively may improve the specificity of preoperative renal tissue characterization and may provide a new modality for treatment monitoring.

A recently developed parallel magnetic resonance (MR) imaging technique, parallel imaging with an augmented radius in k space, was used to accelerate the volumetric interpolated breath-hold examination (VIBE) performed in 20 patients referred for clinical liver imaging. Nonaccelerated MR images were also acquired in these patients. A five-point scale was used to score the quality of the images. The acceleration resulted in reduced image quality: The nonaccelerated images had a significantly higher (P.05) mean score--3.8 +/- 0.3 (SD), indicating good quality--than the accelerated images--3.0 +/- 0.3, indicating acceptable quality. However, for three patients who could not hold their breath for the duration necessary for nonaccelerated imaging, less severe breathing artifacts on the accelerated images resulted in improved quality compared with the quality of the nonaccelerated images. Parallel MR imaging-accelerated VIBE may be beneficial for patients who have difficulty sustaining a breath hold for the duration necessary to perform nonaccelerated imaging.

Many professional societies in the United States recommend screening for colorectal cancer in asymptomatic, average-risk adults, beginning at 50 years of age. Screening achieves two goals: the detection of early-stage nonmetastatic cancers that are surgically curable and the identification and removal of benign adenomatous polyps, the precursor lesions of nearly all adenocarcinomas. Several approaches to screening are available, ranging from the least expensive and least invasive, fecal occult-blood testing, to the more costly and invasive procedures — flexible sigmoidoscopy, barium enema, and colonoscopy. Each of these tests has inherent strengths and weaknesses related to cost, risk, sensitivity, specificity, and availability. . . .

For proper evaluation of the accuracy of CT colonography, prospective multiinstitutional trials would be ideal. Until these trials are available, data can be collectively analyzed. The purpose of this study is to use metaanalysis to assess the reported accuracy of CT colonography compared with conventional colonoscopy for detecting colorectal polyps.Articles comparing CT colonography and conventional colonoscopy were identified, and a standardized form was used to extract relevant study data. Fisher's exact test and the Mantel-Haenszel test were used for pooling of data. A 95% confidence interval (CI) was selected to determine sensitivity and specificity, and the Kruskal-Wallis exact test was used to identify trends relating to polyp size. Meta-analysis methods were used to test strength of results. Comparisons were made for the percentage of polyps detected grouped by size (or = 10 mm, 6-9 mm,or = 5 mm) and the percentage of patients identified who had polyps of the same size.Fourteen studies fulfilled all the study inclusion criteria and gave a total of 1,324 patients and 1,411 polyps. The pooled per-patient sensitivity for polyps 10 mm or larger was (sensitivity [95% CI]) 0.88 (0.84-0.93), for polyps 6-9 mm it was 0.84 (0.80-0.89), and for polyps 5 mm or smaller it was 0.65 (0.57-0.73). The pooled per-polyp sensitivity for polyps 10 mm or larger was 0.81 (0.76-0.85), for polyps 6-9 mm it was 0.62 (0.58-0.67), and for polyps 5 mm or smaller it was 0.43 (0.39-0.47). Sensitivity for detection of polyps increased as the polyp size increased (p0.00005). The pooled overall specificity for detection of polyps larger than 10 mm was 0.95 (0.94-0.97).The specificity and sensitivity of CT colonography are high for polyps larger than 10 mm.

Background & Aims: No multicenter study has been reported evaluating the performance and interobserver variability of computerized tomographic colonography. The aim of this study was to assess the accuracy of computerized tomographic colonography for detecting clinically important colorectal neoplasia (polyps ≥10 mm in diameter) in a multi-institutional study. Methods: A retrospective study was developed from 341 patients who had computerized tomographic colonography and colonoscopy among 8 medical centers. Colonoscopy and pathology reports provided the standard. A random sample of 117 patients, stratified by criterion standard, was requested. Ninety-three patients were included (47% with polyps ≥10 mm; mean age, 62 years; 56% men; 84% white; 40% reported colorectal symptoms; 74% at increased risk for colorectal cancer). Eighteen radiologists blinded to the criterion standard interpreted computerized tomography colonography examinations, each using 2 of 3 different software display platforms. Results: The average area under the receiver operating characteristic curve for identifying patients with at least 1 lesion ≥10 mm was 0.80 (95% lower confidence bound, 0.74). The average sensitivity and specificity were 75% (95% lower confidence bound, 68%) and 73% (95% lower confidence bound, 66%), respectively. Per-polyp sensitivity was 75%. A trend was observed for better performance with more observer experience. There was no difference in performance across software display platforms. Conclusions: Computerized tomographic colonography performance compared favorably with reported performance of fecal occult blood testing, flexible sigmoidoscopy, and barium enema. A prospective study evaluating the performance of computerized tomography colonography in a screening population is indicated.

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

Purpose: It has been proposed that there is an increased frequency of pancreatic abnormalities in patients with primary sclerosing cholangitis (PSC). Our purpose is to compare the frequency of pancreatic abnormalities detected at MRI in patients with PSC and to compare these findings with those found in a matched cohort with other liver diseases. Method: We identified 29 patients who had either a histologic or an endoscopic retrograde cholangiopancreatography diagnosis of PSC and 29 age- and gender-matched patients with liver disease without PSC who underwent MRI at 1.5 T. The protocol included breath-hold T1-weighted gradient echo, echo train, fast spin echo, T2-weighted images and dynamic gadolinium-enhanced MRI. Two blinded readers retrospectively evaluated the MR images for abnormalities of pancreatic size and morphology, T1 and T2 signal intensity, duct size and irregularities, arterial-phase contrast enhancement, focal pancreatic masses, cystic lesions, peripancreatic fluid/edema, ascites, and capsular-like rim surrounding the pancreas. Results: The prevalence of pancreatic and peripancreatic abnormalities was 10 of 29 (35%) in PSC patients and 14 of 29 (48%) in control patients. MR findings included ascites (9 PSC, 12 controls), peripancreatic edema (7 PSC, 11 controls), atrophy (4 PSC, 3 control), increased T2 signal (3 PSC, 4 controls), cystic lesions (2 PSC, 3 controls), abnormal Tl signal (1 PSC, 2 controls), and dilated pancreatic ducts (3 PSC, 2 controls). Quantitative parameters were not significantly different between PSC patients and the control subjects with pancreatic findings. Conclusion: There is no significant difference in pancreatic abnormalities detected on MRI between patients with PSC and those with other liver diseases.

Summary Hutch diverticula are rare congenital diverticula. The general consensus is that they occur secondary to a congenital failure of normal muscle development around the ureteral orifice where Waldeyer sheath anatomically covers the space between the intravesical ureter and muscular layer of the bladder. Our case highlights the radiological appearance of Hutch diverticula and the need for contrast-enhanced imaging to enable accurate evaluation and diagnosis. It illustrates how the presence of periureteric diverticula can contribute to ureteric obstruction and calculus formation; complicate the interpretation of renal tract imaging and the subsequent management of renal calculi.

SUMMARY This article reviews the currently available MR imaging techniques that can be used to perform MR imaging of the liver. Breath-hold T1-weighted GRE sequences, STIR, and half-Fourier single-shot TSE comprise the basic liver examination, depending on MR scanner constraints. Heavily T2-weighted images are useful for characterization of benign lesions such as cysts and hemangiomas, while timed contrast-enhanced 3D spoiled GRE images are important for lesion characterization and possibly improved detection of small lesions not seen on unenhanced images.

Because current techniques for examination and imaging of perianal fistulas tend to underestimate the extent, location, and course of perianal fistulas--information essential for decisions about surgical management--the use of hydrogen peroxide was investigated as an image-enhancing contrast agent for confirmation of the presence of and improvement in the depiction of fistulas during endoanal ultrasonography (US). After conventional endoanal US was performed with a side-fire 7.5- or 10.0-MHz rotating endoprobe, external perianal openings were cannulated and approximately 1 mL of peroxide was administered. After reinsertion of the endoprobe, the entire course of the echogenic fistula, including its relation to the internal and external sphincters and the levator ani muscle, was depicted in real time in three dimensions. This depiction of fistulas permits accurate classification, which facilitates surgical planning. In experience with more than 60 patients, peroxide-enhanced endoanal US was found to be a useful technique for documentation of the presence, number, and internal course of perianal fistulas and for characterization of abnormalities seen at endosonography performed without use of contrast enhancement. In addition, the technique permitted surgeons to stratify patients into treatment groups and has been especially useful for planning surgical treatments.

Diverticular disease is common among the elderly. Because of the advanced age and muted symptoms and signs of many of those affected, diagnosis can be difficult. Consequently, great demands are placed on the physician to diagnose and treat clinically evident diverticular disease. Endoscopic, radiologic, and surgical advances have increased the availability of more definitive therapies for patients with complicated diverticular disease and diverticular hemorrhage.

179 he term “intraductal papillary mucinous tumor of the pancreas” has been introduced as a unifying label for mucin-producing pancreatic neoplasms previously referred to as papillary and villous adenomas, mucinous duct ectasia, and mucin-producing adenomas and carcinomas with or without invasion. Unique clinical, radiologic, and pathologic characteristics of intraductal papillary mucinous tumors of the pancreas have been described [1]. Radiologic examination is necessary for treatment planning because imaging features may indicate the site of tumor origin in the pancreas in addition to extent of spread.

To determine if intravenously administered contrast material improves overall reader confidence in the assessment of the colon, large-bowel wall conspicuity, and diagnostic accuracy in the detection of colorectal polyps and cancers at computed tomographic (CT) colonography.Two hundred patients underwent CT colonography in both supine and prone positions. A five-point scale was used to assess the effect of contrast enhancement on overall reader confidence and bowel wall conspicuity. Eighty-one patients underwent CT colonography with complete colonoscopic or surgical correlation; diagnostic accuracy was compared in 48 patients who received contrast material and 33 who did not.Bowel preparation was ideal in 38 (19%) of 200 patients. Enhanced prone CT images had significantly better scores for reader confidence (4.9 +/- 0.1 vs 4.6 +/- 0.1, P:.005) and bowel wall conspicuity (4.6 +/- 0.2 vs 4.2 +/- 0.2, P:.005) compared with those of nonenhanced prone images despite no significant difference in bowel distention (3.8 +/- 0.2 vs 3.9 +/- 0. 1, P: =.8). Enhancement significantly improved the ability to depict medium (6-9-mm) polyps (75% vs 58%, P:.05). Three large (10-19-mm) polyps were detected only with contrast enhancement; two remained submerged despite dual positioning.The use of intravenously administered contrast material significantly improved reader confidence in the assessment of bowel wall conspicuity and the ability of CT colonography to depict medium polyps in suboptimally prepared colons.

AIMS: We prospectively compared two breath-hold magnetic resonance cholangiopancreatography (MRCP) sequences: single-shot rapid acquisition with relaxation enhancement (RARE) and multislice half-Fourier acquisition single-shot turbo spin echo (HASTE) in imaging the pancreaticobiliary system. PATIENTS AND METHODS: The diagnostic accuracy of single-shot RARE and multislice HASTE was studied in 34 subjects who had undergone conventional cholangiopancreatography. Overall image quality, duct conspicuity, image artifact, signal intensity and contrast-to-noise ratios were assessed independently by two radiologists who were unaware of the underlying diagnosis. RESULTS: Both sequences had comparable diagnostic accuracy regarding a normal biliary system, choledocholithiasis, extra-hepatic and intra-hepatic strictures. Single-shot RARE was superior to multislice HASTE in diagnosing a normal pancreatic system, pancreatic and intrahepatic duct strictures, while providing significantly better image quality (mean ± SE 3.7 ± 0.07 vs 3.3 ± 0.08: P = 0.02) and significantly less image artifact (mean ± SE 3.6 ± 0.07 vs 3.2 ± 0.08: P = 0.01). Single-shot RARE provided significantly better duct conspicuity regarding the pancreatic duct within the body (2.7 ± 0.2 vs 2.1 ± 0.2: P = 0.003) and tail (2.4 ± 0.2 vs 1.6 ± 0.2; P = 0.0001), as well as the intrahepatic ducts (3.0 ± 0.1 vs 2.6 ± 0.1: P = 0.004) but there was no significant difference regarding the remainder of the biliary tree. CONCLUSION: Single-shot RARE provides superior image quality, duct conspicuity with the added advantage of less image artifact and shorter acquisition time. However, volume averaging can cause common bile duct stones to be missed. Therefore, multislice HASTE sequences should still be acquired if choledocholithiasis is suspected. Larger studies are required to assess the diagnostic efficacy of single-shot RARE sequences in pancreatic duct and intra-hepatic duct disease.Morrin, M. M. (2000). Clinical Radiology 55 , 866–873.

The purpose of this case report is to describe the CT imaging features of pulmonary toxicity from gemcitabine, a relatively new chemotherapeutic agent, in three patients. CT features of gemcitabine pulmonary toxicity include ground glass opacity (n = 3), thickened septal lines (n = 3), and reticular opacities (n = 3). Distribution is diffuse and bilateral, and may be symmetric (n = 2) or asymmetric (n = 1). Clinical symptoms and imaging findings are potentially reversible with steroid therapy.

OBJECTIVE. Because laparoscopic cholecystectomy has become the accepted treatment for symptomatic cholelithiasis, radiologists frequently encounter patients who have had this surgery. Although the radiologic features of postoperative bile duct injury are well documented, the imaging features of less well-known complications remain poorly described. One such unusual complication is abscess formation caused by dropped gallstones.CONCLUSION. Although the incidence of dropped gallstones is an uncommon complication of laparoscopic cholecystectomy, it should be recognized as a potential source of both intraabdominal and intrathoracic abscess formation in any patient presenting months to years after undergoing laparoscopic cholecystectomy. These abscesses are not necessarily confined to the right upper quadrant.

Lung ventilation imaging using inhaled oxygen as a contrast medium was performed using both a 0.2 and a 1.5 T clinical magnetic resonance (MR) scanner in eight volunteers. Signal-to-noise-ratios (SNRs) of the ventilation images as well as T1 values of the lung acquired with inhalation of 100% oxygen and room air were calculated. The SNR was 9.7 ± 3.0 on the 0.2 T MR system and 69.5 ± 28.8 on the 1.5 T system (P < 0.001). The mean T1 value on the 0.2 T MR system with subjects breathing room air was 632 ± 54 msec; with 100% oxygen, it was 586 ± 41 msec (P < 0.01). At 1.5 T, the mean values were 904 ± 99 msec and 790 ± 114 msec, respectively (P < 0.0001). We conclude that MR oxygen-enhanced ventilation imaging of the lung is feasible with an open configured 0.2 T MR system. J. Magn. Reson. Imaging 1999;9:838–841. © 1999 Wiley-Liss, Inc.

We evaluated the clinical usefulness of endoluminal CT colonography after an incomplete colonoscopy.We prospectively studied 40 patients in whom the cecum could not be reached endoscopically despite adequate bowel preparation. Endoluminal CT colonography (120 kVp, 120 mA, 3-mm collimation, pitch of 2, 1.5-mm interval reconstruction) was performed within 2 hr of incomplete colonoscopy. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal images were analyzed. Twenty-six patients (65%) underwent barium enema immediately after endoluminal CT colonography. We analyzed colonic distention; duration of endoluminal CT colonography; patient tolerance; number of colonic segments seen at colonoscopy, endoluminal CT colonography, and barium enema; and reasons for incomplete colonoscopy as well as colonic and extracolonic findings.Duration of endoluminal CT colonography was 14.2 +/- 4.6 min (mean +/- SD). Endoluminal CT colonography was better tolerated than colonoscopy or barium enema (p.001). Probable causes for incomplete colonoscopy were identified at endoluminal CT colonography in 74% of 40 patients. Baseline colonic distention in the region of the transverse and right colon was considered adequate before additional air insufflation; however, the addition of air significantly enhanced colonic distention throughout the entire colon (p.001). Endoluminal CT colonography adequately revealed 96% of all colonic segments; in comparison, barium enema adequately revealed 91% of all segments (p.05).In patients with incomplete colonoscopy, endoluminal CT colonography successfully showed the previously unrevealed colon in more than 90% of patients. Endoluminal CT colonography is a rapid, well-tolerated technique that provides clinically useful colonic and extracolonic information and should be considered for all patients who undergo incomplete colonoscopy.

This chapter is a series of short essays composed by key researchers and advocates of computed tomography colonography from several different countries. I hope this will help document some important historical information regarding the development of computed tomography colonography on a global scale. This information is not available in print in any single source and often incorporates a historical perspective never before appearing in print. Each section has its own style, content, and references. The essays are listed in alphabetical order of the country discussed: Argentina, Austria, Belgium, Canada, France, Germany, Ireland, Israel, Italy, Japan, Korea, Sweden, and the United Kingdom. Authors provided photographs of themselves and/or their research team, which are provided in an appendix at the back of the book.

Purpose To compare diagnostic accuracy and patient tolerance of MR colonography with intravenous contrast and luminal air (MRC) to conventional colonoscopy (CC). Materials and methods IRB approval and written informed consent were obtained. Forty-six patients, both screening and symptomatic, underwent MRC followed by CC. The MRC technique employed 3D T1W spoiled gradient echo sequences performed after the administration of gadopenetate dimeglumine, with parallel imaging. The diagnostic accuracy and tolerance of patients for MRC was compared to CC. Results Twenty-four polyps were detected in eighteen patients with CC (5 polyps ≥10 mm, 4 polyps 6–9 mm, 15 polyps ≤5 mm). MRC was 66.7% (12/18) sensitive and 96.4% (27/28) specific for polyp detection on a per-patient basis. When analyzed by polyp size, sensitivity and specificity of MRC was 100% (5/5) and 100% (19/19), respectively, for lesions greater than 10 mm, 100% (4/4) and 100% (20/20) for lesions 6–9 mm, and sensitivity of 20% (3/15) lesions less than 5 mm. The sensitivity and specificity of MRC for detecting significant lesions (>6 mm) was 100% (9/9) and 100% (15/15), respectively. Regarding tolerance of the exams, there were no significant differences between MRC and CC. Thirty-five percent ( n = 16) of patients preferred MRC as a future screening test compared to 33% ( n = 15) for CC. Conclusion MRC using air as an intraluminal contrast agent is a feasible and well-tolerated technique for detecting colonic polyps ≥6 mm in size. Further studies are warranted.

The objective of this article is to describe the experience of the National CT Colonography Trial with radiologist training and qualification testing at CT colonography (CTC) and to correlate this experience with subsequent performance in a prospective screening study.Ten inexperienced radiologists participated in a 1-day educational course, during which partial CTC examinations of 27 cases with neoplasia and full CTC examinations of 15 cases were reviewed using primary 2D and 3D search. Subsequently 15 radiologists took a qualification examination composed of 20 CTC cases. Radiologists who did not pass the first qualification examination attended a second day of focused retraining of 30 cases, which was followed by a second qualification examination. The results of the initial and subsequent qualification tests were compared with reader performance in a large prospective screening trial.All radiologists took and passed the qualification examinations. Seven radiologists passed the qualification examination the first time it was offered, and eight radiologists passed after focused retraining. Significantly better sensitivities were obtained on the second versus the first examination for the retrained radiologists (difference = 16%, p0.001). There was no significant difference in sensitivities between the groups who passed the qualification examination the first time versus those who passed the second time in the prospective study (88% vs 92%, respectively; p = 0.612). In the prospective study, the odds of correctly identifying diseased cases increased by 1.5 fold for every 50-case increase in reader experience or formal training (p0.025).A significant difference in performance was observed among radiologists before formalized training, but testing and focused retraining improved radiologist performance, resulting in an overall high sensitivity across radiologists in a subsequent, prospective screening study.

OBJECTIVE. The purpose of this article is to present the spectrum of radiologic findings of encapsulating peritoneal sclerosis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD).CONCLUSION. Although a rare diagnosis, encapsulating peritoneal sclerosis in patients undergoing CAPD has a high morbidity and mortality. Diagnosis is often delayed because clinical features are insidious and nonspecific. Radiologic imaging may be helpful in the early diagnosis of encapsulating peritoneal sclerosis and in facilitating timely intervention for CAPD patients with encapsulating peritoneal sclerosis.

Full colonic preparation can be onerous and may be poorly tolerated in frail elderly patients. The purpose of this study was to prospectively assess the image quality and diagnostic yield of limited-preparation CT colonography (CTC) in elderly patients with suspected colorectal cancer who were deemed medically unfit or unsuitable for colonoscopy.A prospective study was performed of 67 elderly patients with reduced functional status referred for CTC. Participants were prescribed a limited bowel preparation consisting of a low-residue diet for 3 days, 1 L of 2% oral diatrizoate meglumine (Gastrografin) 24 hours before CTC, and 1 L of 2% oral Gastrografin over the 2 hours immediately before CTC. No cathartic preparation was administered. All colonic segments were graded from 1 to 5 for image quality (1, unreadable; 2, poor; 3, equivocal; 4, good; 5, excellent) and reader confidence. Clinical and conventional colonoscopy follow-up findings were documented, and all colonic and extracolonic pathologic findings were documented.Overall image quality and reader confidence in the evaluation of the colon was rated good or excellent in 84% of the colonic segments. Colonic abnormalities were identified in 12 patients (18%), including four colonic tumors, two polyps, and seven colonic strictures. Incidental extraintestinal findings were detected in 43 patients (64%), including nine patients with lesions radiologically consistent with malignancy.Limited-preparation low-dose CTC is a feasible and useful minimally invasive technique with which to evaluate the colon and exclude gross pathology (mass lesions and polyps1 cm) in elderly patients with diminished performance status, yielding good to excellent image quality.