Objective
To update quality standards for CT colonography based on consensus among opinion leaders within the European Society of Gastrointestinal and Abdominal Radiology (ESGAR)

/pdf/the-second-esgar-consensus-statement-on-ct-colonography-3gqdn4wysv.pdf

The second ESGAR consensus statement on CT colonography

Objective To examine use of CT colonography (CTC) in the English Bowel Cancer Screening Programme (BCSP) and investigate detection rates. Design Retrospective analysis of routinely coded BCSP data. Guaiac faecal occult blood test (gFOBt)-positive screenees undergoing CTC from June 2006 to July 2012 as their first-line colonic investigation were included. Abnormalities found at CTC, subsequent polyp, adenoma and cancer detection and positive predictive value (PPV) were calculated. Detection rates were compared with those observed in gFOBt-positive screenees investigated by colonoscopy. Multilevel logistic regression was used to examine factors associated with variable detection. Results 2731 screenees underwent CTC. Colorectal cancer (CRC) or polyps were suspected in 1027 individuals (37.6%; 95% CI 33.8% to 41.4%); 911 of these underwent confirmatory testing. 124 screenees had CRC (4.5%) and 533 had polyps (19.5%), 468 adenomatous (17.1%). Overall detection was 24.1% (95% CI 21.5% to 26.6%) for CRC or polyps and 21.7% (95% CI 19.2% to 24.1%) for CRC or adenoma. Advanced neoplasia was detected in 504 screenees (18.5%; 95% CI 16.1% to 20.8%). PPV for CRC or polyp was 72.1% (95% CI 66.6% to 77.6%). By comparison, 9.0% of 72 817 screenees undergoing colonoscopy had cancer and 50.6% had polyps; advanced neoplasia was detected in 32.7%. CTC detection rates and PPV were higher at centres with experienced radiologists (>1000 examinations) and at high-volume centres (>175 cases/radiologist/annum). Centres using three-dimensional interpretation detected more neoplasia. Conclusions In the BCSP, detection rates after positive gFOBt are lower for CTC than colonoscopy, although populations undergoing the two tests are different. Centres with more experienced radiologists have higher detection and accuracy. Rigorous quality assurance of BCSP radiology is needed.

https://gut.bmj.com/content/gutjnl/63/6/964.full.pdf

Use of CT colonography in the English Bowel Cancer Screening Programme

Objective: CT colonography (CTC) is recommended after positive faecal occult blood testing (FOBt) when colonoscopy is incomplete or infeasible. We aimed to estimate the sensitivity and specificity of CTC for colorectal cancer and adenomatous polyps following positive FOBt via systematic review. Methods: The MEDLINE, EMBASE, AMED and Cochrane Library databases were searched for CTC studies reporting sensitivity and specificity for colorectal cancer and adenomatous polyps. Included subjects had tested FOBt-positive by guaiac or immunochemical methods. Per-patient detection rates were summarized via forest plots. Meta-analysis of sensitivity and specificity was conducted using a bivariate random effects model and the average operating point calculated. Results: Of 538 articles considered, 5 met inclusion criteria, describing results from 622 patients. Research study quality was good. CTC had a high per-patient average sensitivity of 88.8 % (95 % CI 83.6 to 92.5 %) for ≥6 mm adenomas or colorectal cancer, with low between-study heterogeneity. Specificity was both more heterogeneous and lower, at an average of 75.4 % (95 % CI 58.6 to 86.8 %). Conclusion: Few studies have investigated CTC in FOBt-positive individuals. CTC is sensitive at a ≥6 mm threshold but specificity is lower and variable. Despite the limited data, these results suggest that CTC may adequately substitute for colonoscopy when the latter is undesirable. Key Points: • FOBt is the most common mass screening test for colorectal cancer. • Few studies evaluate CT colonography after positive FOBt. • CTC is approximately 89 % sensitive for ≥6 mm adenomas/cancer in this setting. • Specificity is lower, at approximately 75 %, and more variable. • CT colonography is a good alternative when colonoscopy is undesirable. © 2014 European Society of Radiology.

/pdf/sensitivity-and-specificity-of-ct-colonography-for-the-3ica4cs07x.pdf

Sensitivity and specificity of CT colonography for the detection of colonic neoplasia after positive faecal occult blood testing: systematic review and meta-analysis

Screening and surveillance for colorectal cancer: state of the art

Primary central nervous system lymphoma (PCNSL) is a rare aggressive high-grade type of extranodal lymphoma. PCNSL can have a variable imaging appearance and can mimic other brain disorders such as encephalitis, demyelination, and stroke. In addition to PCNSL, the CNS can be secondarily involved by systemic lymphoma. Computed tomography and conventional MRI are the initial imaging modalities to evaluate these lesions. Recently, however, advanced MRI techniques are more often used in an effort to narrow the differential diagnosis and potentially inform diagnostic and therapeutic decisions.

Neuroimaging in Central Nervous System Lymphoma.

Objective
To determine the positive predictive value (PPV) for polyps ≥6 mm detected at CT colonography (CTC) performed without cathartic preparation, with low-dose iodine faecal tagging regimen and to evaluate patient experience.

CT colonography without cathartic preparation: positive predictive value and patient experience in clinical practice.

Background/Objectives: Primary central nervous system lymphoma (PCNSL) is a rare tumour with poor prognosis. Due to the increased number of patients with PCNSL over the past two decades our purpose are to describe magnetic resonance imaging (MRI) and Computed Tomography (CT) findings in (PCNSL) of the brain, and to study the differences between immunocompetent and immunodeficient patients with PCNSL. Methods : A retrospective, descriptive study was performed with 59 patients diagnosed of PCNSL in two hospitals from 1997 to 2010. Immunocompetent (n=38) and immunodeficient (n=21) patients were compared and differences between both groups were analyzed. Patients were evaluated according to sex, age, median time from clinical symptoms presentation to pathologic diagnosis, clinical symptoms, location, number of lesions, size, MRI and CT characteristics. Significance was defined as p < 0.05. Results : MRI findings: 50% of lesions in immunocompetent and 52.4% in immunodeficient group were heterogeneous, 89.5% of lesions in immunocompetent and 85,7% in immunodeficient were hypo-isointense on T1WI; 63.2% of lesions in immunocompetent and 76.2% in immunodeficient group were hyperintense on T2WI. CT images: 48.39% of lesions in immunocompetent and 20% in immunodeficient group were hyperdense. Statistically significant differences between immunocompetent and immunodeficient patients were found when evaluating the age ( p < 0.000) and median time from clinical symptoms presentation to pathologic diagnosis ( p < 0.008). Conclusions: MRI and CT are able to define imaging characteristics of PCNSL, promoting a quick diagnosis. There are no significant differences between immunocompetent and immunodeficient patients for MR and CT features.

/pdf/findings-at-presentation-in-primary-cns-diffuse-large-b-cell-kip9dr7k3f.pdf

Manuela Fontanillo Fontanillo

Papers

CT colonography without cathartic preparation: positive predictive value and patient experience in clinical practice.

Findings at presentation in primary CNS diffuse large B-cell lymphoma of the brain: A comparison of immunocompetent and immunodeficient patients