Jaap Stoker

Polyp miss rate determined by tandem colonoscopy: a systematic review

BACKGROUND AND AIMS:Colonoscopy is the best available method to detect and remove colonic polyps and therefore serves as the gold standard for less invasive tests such as virtual colonoscopy. Although gastroenterologists agree that colonoscopy is not infallible, there is no clarity on the numbers and rates of missed polyps. The purpose of this systematic review was to obtain summary estimates of the polyp miss rate as determined by tandem colonoscopy.METHODS:An extensive search was performed within PUBMED, EMBASE, and the Cochrane Library databases to identify studies in which patients had undergone two same-day colonoscopies with polypectomy. Random effects models based on the binomial distribution were used to calculate pooled estimates of miss rates.RESULTS:Six studies with a total of 465 patients could be included. The pooled miss rate for polyps of any size was 22% (95% CI: 19–26%; 370/1,650 polyps). Adenoma miss rate by size was, respectively, 2.1% (95% CI: 0.3–7.3%; 2/96 adenomas ≥10 mm), 13% (95% CI: 8.0–18%; 16/124 adenomas 5–10 mm), and 26% (95% CI: 27–35%; 151/587 adenomas 1–5 mm). Three studies reported data on nonadenomatous polyps: zero of eight nonadenomatous polyps ≥10 mm were missed (0%; 95% CI: 0–36.9%) and 83 of 384 nonadenomatous polyps <10 mm were missed (22%; 95% CI: 18–26%).CONCLUSIONS:Colonoscopy rarely misses polyps ≥10 mm, but the miss rate increases significantly in smaller sized polyps. The available evidence is based on a small number of studies with heterogeneous study designs and inclusion criteria.

Inflammatory bowel disease diagnosed with US, MR, scintigraphy, and CT: meta-analysis of prospective studies.

PURPOSE To compare, by performing a meta-analysis, the accuracies of ultrasonography (US), magnetic resonance (MR) imaging, scintigraphy, computed tomography (CT), and positron emission tomography (PET) in the diagnosis of inflammatory bowel disease (IBD). MATERIALS AND METHODS MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched for studies on the accuracy of US, MR imaging, scintigraphy, CT, and PET, as compared with a predefined reference standard, in the diagnosis of IBD. Sensitivity and specificity estimates were calculated on per-patient and per-bowel-segment bases by using a bivariate random-effects model. RESULTS Thirty-three studies, from a search that yielded 1406 articles, were included in the final analysis. Mean sensitivity estimates for the diagnosis of IBD on a per-patient basis were high and not significantly different among the imaging modalities (89.7%, 93.0%, 87.8%, and 84.3% for US, MR imaging, scintigraphy, and CT, respectively). Mean per-patient specificity estimates were 95.6% for US, 92.8% for MR imaging, 84.5% for scintigraphy, and 95.1% for CT; the only significant difference in values was that between scintigraphy and US (P = .009). Mean per-bowel-segment sensitivity estimates were lower: 73.5% for US, 70.4% for MR imaging, 77.3% for scintigraphy, and 67.4% for CT. Mean per-bowel-segment specificity estimates were 92.9% for US, 94.0% for MR imaging, 90.3% for scintigraphy, and 90.2% for CT. CT proved to be significantly less sensitive and specific compared with scintigraphy (P = .006) and MR imaging (P = .037) CONCLUSION No significant differences in diagnostic accuracy among the imaging techniques were observed. Because patients with IBD often need frequent reevaluation of disease status, use of a diagnostic modality that does not involve the use of ionizing radiation is preferable.

Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE): Determining Therapeutic Goals for Treat-to-Target.

OBJECTIVES:The Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) program was initiated by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD). It examined potential treatment targets for inflammatory bowel disease (IBD) to be used for a “treat-to-target” clinical management strategy using an evidence-based expert consensus process.METHODS:A Steering Committee of 28 IBD specialists developed recommendations based on a systematic literature review and expert opinion. Consensus was gained if ≥75% of participants scored the recommendation as 7–10 on a 10-point rating scale (where 10=agree completely).RESULTS:The group agreed upon 12 recommendations for ulcerative colitis (UC) and Crohn’s disease (CD). The agreed target for UC was clinical/patient-reported outcome (PRO) remission (defined as resolution of rectal bleeding and diarrhea/altered bowel habit) and endoscopic remission (defined as a Mayo endoscopic subscore of 0–1). Histological remission was considered as an adjunctive goal. Clinical/PRO remission was also agreed upon as a target for CD and defined as resolution of abdominal pain and diarrhea/altered bowel habit; and endoscopic remission, defined as resolution of ulceration at ileocolonoscopy, or resolution of findings of inflammation on cross-sectional imaging in patients who cannot be adequately assessed with ileocolonoscopy. Biomarker remission (normal C-reactive protein (CRP) and calprotectin) was considered as an adjunctive target.CONCLUSIONS:Evidence- and consensus-based recommendations for selecting the goals for treat-to-target strategies in patients with IBD are made available. Prospective studies are needed to determine how these targets will change disease course and patients’ quality of life.

Imaging techniques for assessment of inflammatory bowel disease: Joint ECCO and ESGAR evidence-based consensus guidelines

The management of patients with IBD requires evaluation with objective tools, both at the time of diagnosis and throughout the course of the disease, to determine the location, extension, activity and severity of inflammatory lesions, as well as, the potential existence of complications. Whereas endoscopy is a well-established and uniformly performed diagnostic examination, the implementation of radiologic techniques for assessment of IBD is still heterogeneous; variations in technical aspects and the degrees of experience and preferences exist across countries in Europe. ECCO and ESGAR scientific societies jointly elaborated a consensus to establish standards for imaging in IBD using magnetic resonance imaging, computed tomography, ultrasonography, and including also other radiologic procedures such as conventional radiology or nuclear medicine examinations for different clinical situations that include general principles, upper GI tract, colon and rectum, perineum, liver and biliary tract, emergency situation, and the postoperative setting. The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas such as the comparison of diagnostic accuracy between different techniques, the value for therapeutic monitoring, and the prognostic implications of particular findings.

Diagnostic Imaging of Colorectal Liver Metastases with CT, MR Imaging, FDG PET, and/or FDG PET/CT: A Meta-Analysis of Prospective Studies Including Patients Who Have Not Previously Undergone Treatment

PURPOSE To obtain diagnostic performance values of computed tomography (CT), magnetic resonance (MR) imaging, fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET), and FDG PET/CT in the detection of colorectal liver metastases in patients who have not previously undergone therapy. MATERIALS AND METHODS A comprehensive search was performed for articles published from January 1990 to January 2010 that fulfilled the following criteria: a prospective study design was used; the study population included at least 10 patients; patients had histopathologically proved colorectal cancer; CT, MR imaging, FDG PET, or FDG PET/CT was performed for the detection of liver metastases; intraoperative findings or those from histopathologic examination or follow-up were used as the reference standard; and data for calculating sensitivity and specificity were included. Study design characteristics, patient characteristics, imaging features, reference tests, and 2 × 2 tables were recorded. RESULTS Thirty-nine articles (3391 patients) were included. Variation existed in study design characteristics, patient descriptions, imaging features, and reference tests. The sensitivity estimates of CT, MR imaging, and FDG PET on a per-lesion basis were 74.4%, 80.3%, and 81.4%, respectively. On a per-patient basis, the sensitivities of CT, MR imaging, and FDG PET were 83.6%, 88.2%, and 94.1%, respectively. The per-patient sensitivity of CT was lower than that of FDG PET (P = .025). Specificity estimates were comparable. For lesions smaller than 10 mm, the sensitivity estimates for MR imaging were higher than those for CT. No differences were seen for lesions measuring at least 10 mm. The sensitivity of MR imaging increased significantly after January 2004. The use of liver-specific contrast material and multisection CT scanners did not provide improved results. Data about FDG PET/CT were too limited for comparisons with other modalities. CONCLUSION MR imaging is the preferred first-line modality for evaluating colorectal liver metastases in patients who have not previously undergone therapy. FDG PET can be used as the second-line modality. The role of FDG PET/CT is not yet clear owing to the small number of studies. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100729/-/DC1.

Computed tomography and magnetic resonance imaging in staging of uterine cervical carcinoma: a systematic review

OBJECTIVE The goal of this article is to systematically review the available evidence on the diagnostic performance of computed tomography (CT) and magnetic resonance imaging (MRI) in staging of cervical carcinoma. METHODS A comprehensive computer literature search was performed in MEDLINE and EMBASE databases from January 1985 to May 2002. Two reviewers independently scored methodological quality of included studies and extracted relevant data for data analysis. A bivariate random effect approach was used to summarize estimates of sensitivity and specificity values. Covariates were added to this model to study the influence of sample size, publication year, methodological criteria, and MRI techniques on summary estimates. RESULTS Fifty-seven articles were included. In 49 articles one imaging modality was evaluated (MRI, 38; CT, 11), and in 8 articles, both. Inclusion criteria were: minimum of 10 patients included, histopathology as reference standard, sufficient data presented to construct 2(x) 2 tables. The exclusion criterion was: data reported elsewhere in more detail. Sensitivity estimates for parametrial invasion were 74% (95% C: 68-79%) for MRI and 55% (95% CI: 44-66%) for CT, and for lymph node involvement, 60% (95% CI 52%-68%) and 43% (95% CI: 37-57%), respectively. MRI and CT had comparable specificities for parametrial invasion and lymph node involvement. For bladder invasion and rectum invasion the sensitivities for MRI were respectively 75% (95% CI: 66-83%) and 71% (95% CI: 53-83%), higher compared with CT. The specificity in evaluating bladder invasion for MRI was significantly higher compared with CT: 91% (95% CI: 83-95%) for MRI and 73% (95% CI: 52-87%) for CT. The specificities for rectum invasion were comparable. Differences in patient sample size, publication year, methodological criteria, and MRI techniques had no effect on the summary estimates. CONCLUSIONS For overall staging of cervical carcinoma, MRI is more accurate than CT.

The diagnostic accuracy of US, CT, MRI and 1H-MRS for the evaluation of hepatic steatosis compared with liver biopsy: a meta-analysis

ObjectiveTo meta-analyse the diagnostic accuracy of US, CT, MRI and 1H-MRS for the evaluation of hepatic steatosis.MethodsFrom a comprehensive literature search in MEDLINE, EMBASE, CINAHL and Cochrane (up to November 2009), articles were selected that investigated the diagnostic performance imaging techniques for evaluating hepatic steatosis with histopathology as the reference standard. Cut-off values for the presence of steatosis on liver biopsy were subdivided into four groups: (1) >0, >2 and >5% steatosis; (2) >10, >15 and >20%; (3) >25, >30 and >33%; (4) >50, >60 and >66%. Per group, summary estimates for sensitivity and specificity were calculated. The natural-logarithm of the diagnostic odds ratio (lnDOR) was used as a single indicator of test performance.Results46 articles were included. Mean sensitivity estimates for subgroups were 73.3–90.5% (US), 46.1–72.0% (CT), 82.0–97.4% (MRI) and 72.7–88.5% (1H-MRS). Mean specificity ranges were 69.6–85.2% (US), 88.1–94.6% (CT), 76.1–95.3% (MRI) and 92.0–95.7% (1H-MRS). Overall performance (lnDOR) of MRI and 1H-MRS was better than that for US and CT for all subgroups, with significant differences in groups 1 and 2.ConclusionMRI and 1H-MRS can be considered techniques of choice for accurate evaluation of hepatic steatosis.

Acute appendicitis: meta-analysis of diagnostic performance of CT and graded compression US related to prevalence of disease.

PURPOSE This study was a head-to-head comparison of graded compression ultrasonography (US) and computed tomography (CT) in helping diagnose acute appendicitis with an emphasis on diagnostic value at different disease prevalences, commonly occurring in various hospital settings. MATERIALS AND METHODS MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched from January 1966 to February 2006. Prospective trials were selected if they (a) compared graded compression US and CT in the same patient population; (b) included more than 10 patients, otherwise, the study was considered a case report; (c) evaluated mainly adults or adolescents; (d) used surgery and/or clinical follow-up as reference standard; and (e) reported data to calculate 2 x 2 contingency tables for graded compression US and CT. Estimates of sensitivity, specificity, and positive and negative likelihood ratios (LRs) for US and CT were calculated. Posttest probabilities after CT and US were calculated for various clinically relevant prevalences. RESULTS Six studies were included, evaluating 671 patients (mean age range, 26-38 years); prevalence of acute appendicitis was 50% (range, 13%-77%). Positive LR was 9.29 (95% confidence interval [CI]: 6.9, 12.6) for CT and 4.50 (95% CI: 3.0, 6.7; P = .011) for US, yielding posttest probabilities for positive tests of 90% and 82%, respectively. Negative LR was 0.10 (95% CI: 0.06, 0.17) for CT and 0.27 (95% CI: 0.17, 0.43) for US (P = .013), resulting in posttest probabilities of 9% and 21%, respectively. Posttest probabilities for positive tests were markedly decreased at lower prevalences. CONCLUSION In head-to-head comparison studies of diagnostic imaging, CT had a better test performance than did graded compression US in diagnosing appendicitis. Ignoring the relationship between prevalence (pretest probability) and diagnostic value may lead to an inaccurate estimation of diagnostic performance.

Ultrasonography, computed tomography and magnetic resonance imaging for diagnosis and determining resectability of pancreatic adenocarcinoma: a meta-analysis.

Objective: To compare ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) in the diagnosis and determination of resectability of pancreatic adenocarcinoma. Methods: Articles reporting US, CT, or MRI data of patients with known or suspected pancreatic adenocarcinoma and at least 20 patients verified with histopathology, surgical findings, or follow-up were included. A bivariate random effects approach was used to calculate sensitivity and specificity for diagnosis and resectability of pancreatic adenocarcinoma. Results: Sixty-eight articles fulfilled all inclusion criteria. For diagnosis, sensitivities of helical CT, conventional CT, MRI, and US were 91%, 86%, 84%, and 76% and specificities were 85%, 79%, 82%, and 75% respectively. Sensitivities for MRI and US were significantly lower compared with helical CT (P = 0.04 and P = 0.0001). For determining resectability, sensitivities of helical CT, conventional CT, MRI, and US were 81%, 82%, 82, and 83% and specificities were 82%, 76%, 78%, and 63% respectively. Specificity of US was significantly lower compared with helical CT (P = 0.011). Conclusions: Helical CT is preferable as an imaging modality for the diagnosis and determination of resectability of pancreatic adenocarcinoma.

Imaging Patients with Acute Abdominal Pain

UNLABELLED Acute abdominal pain may be caused by a myriad of diagnoses, including acute appendicitis, diverticulitis, and cholecystitis. Imaging plays an important role in the treatment management of patients because clinical evaluation results can be inaccurate. Performing computed tomography (CT) is most important because it facilitates an accurate and reproducible diagnosis in urgent conditions. Also, CT findings have been demonstrated to have a marked effect on the management of acute abdominal pain. The cost-effectiveness of CT in the setting of acute appendicitis was studied, and CT proved to be cost-effective. CT can therefore be considered the primary technique for the diagnosis of acute abdominal pain, except in patients clinically suspected of having acute cholecystitis. In these patients, ultrasonography (US) is the primary imaging technique of choice. When costs and ionizing radiation exposure are primary concerns, a possible strategy is to perform US as the initial technique in all patients with acute abdominal pain, with CT performed in all cases of nondiagnostic US. The use of conventional radiography has been surpassed; this examination has only a possible role in the setting of bowel obstruction. However, CT is more accurate and more informative in this setting as well. In cases of bowel perforation, CT is the most sensitive technique for depicting free intraperitoneal air and is valuable for determining the cause of the perforation. Imaging is less useful in cases of bowel ischemia, although some CT signs are highly specific. Magnetic resonance (MR) imaging is a promising alternative to CT in the evaluation of acute abdominal pain and does not involve the use of ionizing radiation exposure. However, data on the use of MR imaging for this indication are still sparse. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/content/253/1/31/suppl/DC1.