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Increasingly, constructive thought is being given to non-interpretive competencies in Radiology training and practice. Two of these are “Practice-Based Learning” and “Systems-Based Practice”. These areas are evolving. It seems likely that, in some way, the paradigm of “Evidence-Based Practice” (EBP) derived from the McMaster/Centre for Evidence-Based Medicine (CEBM) methodology will form part of these new disciplines. This introductory article sets the scene for this Feature Section in Abdominal Imaging consisting entirely of short “Critically Appraised Topics” produced using EBP techniques. It is hoped that this will stimulate further discussion and consideration of the potential role of EBP in radiology education.

Malone DE
Department of Radiology, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland. dmalone@ucd.ie

BACKGROUND: The purpose of this study is to evaluate recently reported outcomes for treatment options for proximal cholangiocarcinoma (CCA). MATERIALS AND METHODS: Standard evidence based practice techniques were used to formulate a question, search, appraise and evaluate the retrieved literature. Our question was “In patients with CCA, how do stenting alone, stenting in addition to brachytherapy (BT) or photodynamic therapy (PDT), resection and orthotopic liver transplantation with neoadjuvant chemoradiation (OLT) compare for long-term survival? RESULTS: Level 1b survival data was available for stenting alone (179 days), BT and metal stenting (388 days) and PDT with plastic stenting (493 days) and no survival difference was evident with metal vs. plastic stenting or unilateral vs. bilateral stenting. Five year survival data (level 3) was available for OLT (80%), formally curative trisegmentectomy with or without portal vein resection (72% and 52%) and hepatectomy (18%-23%). CONCLUSION: All patients with proximal CCA should be reviewed by a multidisciplinary team to determine appropriate treatment. For unresectable CCA, patients should be assessed for OLT with neoadjuvant chemoradiation, while those who are unsuitable would appear to have the longest survival with PDT. Extended resection in operable candidates may improve survival over right or left hepatectomy but increased perioperative mortality is a consideration.

Killeen RP　Harte S　Maguire D　Malone DE
Department of Radiology, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland. rokilleen@yahoo.com

In clinical radiology, there are numerous examples of new techniques that were initially enthusiastically promoted and then subsequently abandoned when early promise was not realized in routine patient care. Appropriateness of new or established interventional radiology techniques to specific clinical conditions must be determined from clinical experience, from communication with experts in the field and/or careful review of available medical literature, and on an individual patient basis by means of review of clinical notes and diagnostic imaging studies. For patients with liver neoplasms, regional techniques such as radiofrequency ablation (RFA) have been developed and are now the subject of ongoing research. This article describes the utilization of Evidence-Based Practice (EBP) techniques as a means of deciding the appropriateness of percutaneous RFA in treating colorectal liver metastases (CLM).

McGrane S　McSweeney SE　Maher MM
Department of Radiology, Cork University Hospital, University College Cork, Cork, Ireland.

BACKGROUND: This is a study using Evidence Based Practice (EBP) technique to evaluate if non-calcified renal lesions detected with ultrasound, suspected to represent an angiomyolipoma (AML), need a CT to rule out a renal cell carcinoma (RCC). METHODS: The secondary and primary literature were searched for all relevant information. This was appraised for validity and strength. The results from the papers with the highest level of evidence were grouped together and analyzed. RESULTS: Three papers in the primary literature constituted the highest level of evidence. In total these three papers examined 220 lesions. The prevalence of AML was 45% in this sample. Overall, hyperechoic non-calcified renal lesions had a sensitivity of 0.99 (95% confidence interval (CI) 0.97-1.00), a specificity of 0.43 (95% CI 0.34-0.51), a positive predictive value (PPV) of 0.58 and a negative predictive value (NPV) of 0.98 for AMLs. 57.4% of RCCs were hyperechoic to renal parenchyma. Two of the studies found that posterior acoustic shadowing had a sensitivity of 0.34 (95% CI 0.40-0.56) and a specificity of 1.0 (95% CI 1.0-1.0) for AML. CONCLUSIONS: From the surprisingly limited evidence available in the literature, it must be concluded that all non-calcified echogenic renal lesions detected with ultrasound need a CT to rule out an RCC.

Farrelly C　Delaney H　McDermott R　Malone D
Radiology Department, St. James’s Hospital, James’s Street, Dublin 8, Dublin, Ireland. farrellycormac@gmail.com

BACKGROUND: We wondered whether noncontrast CT performs better than the intravenous urogram (IVU) in the detection of urinary calculi. METHODS: A comprehensive search of the literature was undertaken in order to answer the above question. Both primary and secondary sources of evidence were searched. The retrieved evidence was then appraised. RESULTS: The strongest evidence was in a meta-analysis by Worster and colleagues (level 1a evidence according to the Oxford/CEBM levels of evidence). This was an analysis of four studies with a total of 296 patients who underwent intravenous urogram and noncontrast CT. This study shows that CT has better diagnostic performance than IVU for the detection of urinary stones. CONCLUSIONS: The literature suggests that CT should be utilized in preference to IVU for patients with suspected urolithiasis.

Shine S
Department of Radiology, Mater Misericordiae University Hospital, Eccles Street, Dublin 7, Ireland. sueshine@eircom.net

Abdominal Imaging,2008,000,1. no12

Recent advances in CT and MR technology, particularly the advent of multidetector CT (MDCT), the advent of rapidly changing gradients in industry standard MRI scanners, enabling ultrafast sequences, have led to an expansion in the role of cross sectional imaging in the investigation of small bowel disorders. We conducted an evidence-based review of MR enteroclysis (MRE) and how it performs in comparison to CT enteroclysis (CTE) and the gold standard of conventional enteroclysis (CE) for diagnosis of small bowel Crohn’s disease and small bowel neoplasia. We used the standard 5 step evidence-based medicine method of ask, search, appraise, apply and evaluate. We found 3 relevant level 1B studies, and one level 3B study. No studies evaluating MRE in small bowel neoplasia were found. MRE does not perform as well as CE in evaluation of fine mucosal detail, but the additional extraluminal detail, and absence of ionising radiation enhances its overall performance. It was not possible to establish the relative diagnostic performances of MRE and CTE from existing literature. CTE does involve patient irradiation. For patients in whom jejunal intubation and enteroclysis is considered to evaluate the small bowel, MRE should be considered the first-line investigation, local resources and expertise permitting.

Ryan ER　Heaslip IS
Department of Radiology, St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland. ronan.ryan@st-vincents.ie

Barium enteroclysis has been traditionally used in the diagnosis of small bowel Crohn’s disease. Recently CT enteroclysis has been developed as an alternative imaging technique for small bowel Crohn’s disease. A search and critical appraisal of the literature was performed to determine which technique is better for diagnosis of Crohn’s disease. The best current evidence indicates that CT enteroclysis is a good test for the diagnosis of Crohn’s disease but barium enteroclysis may also be required in a small group of patients.

Kerr JM
Department of Radiology, Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland. jenniekerr@yahoo.co.uk

Acute pancreatitis is a disease with a broad spectrum of findings that varies in severity from mild interstitial or edematous pancreas to severe forms with significant local and systemic complications that are associated with a substantial degree of morbidity and mortality. Several scoring systems are used to assess the severity and predict the outcome and prognosis of acute pancreatitis. These include the Ranson, Acute Physiology And Chronic Health Evaluation II (APACHE II) and Glasgow scales. The CT severity index (CTSI) derived by Balthazar et al. has become widely used for description of CT findings in acute pancreatitis. The purpose of this project was to examine the current best evidence about regarding the effect of using a CTSI on patient outcome and its value in comparison with other widely used scoring systems.

Alhajeri A　Erwin S
Faculty of Radiologists, Royal College of Surgeons in Ireland and St Vincent’s University Hospital (SVUH), Dublin, Ireland. nhajri@gmail.com

Cholangiocarcinoma is a serious but common complication of primary sclerosing cholangitis (PSC) that is often difficult to diagnose. The aim of this study was to conduct an evidence based radiology review of the diagnostic modalities used to identify cholangiocarcinoma in patients with PSC. A systematic review of the current best evidence was carried out and a diagnostic algorithm for cholangiocarcinoma in PSC is proposed.

Walker SL　McCormick PA
National Liver Unit, St. Vincent’s University Hospital, Elm Park, Dublin 4, Ireland. slw007@gmail.com