Dermot E. Malone

Evidence-based radiology: how to quickly assess the validity and strength of publications in the diagnostic radiology literature

The aim of this study was to show how evidence-based medicine (EBM) techniques can be applied to the appraisal of diagnostic radiology publications. A clinical scenario is described: a gastroenterologist has questioned the diagnostic performance of magnetic resonance cholangiopancreatography (MRCP) in a patient who may have common bile duct (CBD) stones. His opinion was based on an article on MRCP published in “Gut.” The principles of EBM are described and then applied to the critical appraisal of this paper. Another paper on the same subject was obtained from the radiology literature and was also critically appraised using explicit EBM criteria. The principles for assessing the validity and strength of both studies are outlined. All statistical parameters were generated quickly using a spreadsheet in Excel format. The results of EBM assessment of both papers are presented. The calculation and application of confidence intervals (CIs) and likelihood ratios (LRs) for both studies are described. These statistical results are applied to individual patient scenarios using graphs of conditional probability (GCP). Basic EBM principles are described and additional points relevant to radiologists discussed. Online resources for EBR practice are identified. The principles of EBM and their application to radiology are discussed. It is emphasized that sensitivity and specificity are point estimates of the “true” characteristics of a test in clinical practice. A spreadsheet can be used to quickly calculate CIs, LRs and GCPs. These give the radiologist a better understanding of the meaning of diagnostic test results in any patient or population of patients.

Hepatocellular Carcinoma: Illustrated Guide to Systematic Radiologic Diagnosis and Staging According to Guidelines of the American Association for the Study of Liver Diseases

Hepatocellular carcinoma is a malignancy that predominantly occurs in the setting of cirrhosis. Its incidence is rising worldwide. Hepatocellular carcinoma differs from most malignancies because it is commonly diagnosed on the basis of imaging features alone, without histologic confirmation. The guidelines from the American Association for the Study of Liver Diseases (AASLD) are a leading statement for the diagnosis and staging of hepatocellular carcinoma, and they have recently been updated, incorporating several important changes. AASLD advocates the use of the Barcelona Clinic Liver Cancer (BCLC) staging system, which combines validated imaging and clinical predictors of survival to determine stage and which links staging with treatment options. Each stage of the BCLC system is outlined clearly, with emphasis on case examples. Focal liver lesions identified at ultrasonographic surveillance in patients with cirrhosis require further investigation. Lesions larger than 1 cm should be assessed with multiphasic computed tomography or magnetic resonance imaging. Use of proper equipment and protocols is essential. Lesions larger than 1 cm can be diagnosed as hepatocellular carcinoma from a single study if the characteristic dynamic perfusion pattern of arterial hyperenhancement and venous or delayed phase washout is demonstrated. If the imaging characteristics of hepatocellular carcinoma are not met, the alternate modality should be performed. Biopsy should be used if neither modality is diagnostic of hepatocellular carcinoma. Once the diagnosis has been made, the cancer should be assigned a BCLC stage, which will help determine suitable treatment options. Radiologists require a systematic approach to diagnose and stage hepatocellular carcinoma with appropriate accuracy and precision.

Portal venous gas: detection by gray-scale and Doppler sonography in the absence of correlative findings on computed tomography

Two cases are described in which portal venous gas (PVG) was detectable by ultrasound, but the liver appeared normal on computed tomography (CT). The finding of PVG was associated with ischemic bowel in one case but was a benign finding in the other case. The gray-scale and Doppler ultrasound findings associated with PVG are described. This case report illustrates two key points. First, ultrasound may detect gas within the portal venous system when CT is negative. Second, when PVG is detected on ultrasound, urgent clinical assessment followed by contrast-enhanced CT is indicated to assess for associated intestinal ischemia.

Percutaneous radiofrequency ablation of lung tumors: evaluation of the literature using evidence-based techniques.

Purpose The aim of this study was to evaluate the literature for articles assessing radiofrequency ablation (RFA) for pulmonary malignancy. Materials and Methods The “bottom-up” approach to evidence-based practice was applied by 2 reviewers to the retrieval and appraisal of original research articles published on pulmonary RFA between 2002 and 2009. Primary lung cancer and pulmonary metastases data were analyzed separately. The relationship between the percentage of local recurrence rate and lesion size, patient age, follow-up duration, and time to local recurrence was assessed using Spearmans rank correlation. Discrete time series were used to evaluate time trends. Results Secondary evidence yielded 1 review of 26 observational studies. Primary evidence yielded 46 studies that seemed suitable for detailed appraisal. A total of 2905 ablations were performed in 1584 patients. Eight studies evaluated primary lung cancers alone, 11 evaluated pulmonary metastases alone, 25 evaluated both, and 2 did not specify the histology. Results revealed trends toward increasing use of conscious sedation over general anesthesia, increasing use of multitined probes, decreasing size of nodule selection, and use of positron emission tomography/computed tomography as the optimal follow-up tool. Mean morbidity was 24.6%. The most prevalent side effects included pneumothorax (28.3%), pleural effusions (14.8%), and pain (14.1%). Procedure-related mortality ranged from 0 to 5.6, with an overall procedure-related mortality rate of 0.21%. There were 282 (12.2%) local recurrences occurring at a mean of 13 months. The mean overall survival rate was 59.4%, and the cancer-specific survival rate was 82.6%. Conclusions This evidence-based practice review of pulmonary RFA shows it to be a promising treatment for pulmonary malignancy in carefully selected patient populations. Studies with higher levels of evidence, including case-control, prospective nonrandomized and randomized trials, that compare RFA with alternative contemporary local treatments are urgently needed.

Acute Budd–Chiari syndrome with liver failure: The experience of a policy of initial interventional radiological treatment using transjugular intrahepatic portosystemic shunt

Background and Aims:  The optimal management of acute Budd–Chiari syndrome (BCS) with liver failure is controversial. Options include anticoagulation, portal systemic shunting or liver transplantation. In recent years, transjugular intrahepatic portosystemic shunts (TIPS) have been tried in place of shunt surgery. We report our experience with a policy of initial interventional radiological treatment (TIPS) in this patient group.

Do all non-calcified echogenic renal lesions found on ultrasound need further evaluation with CT?

BackgroundThis 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).MethodsThe 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.ResultsThree 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.ConclusionsFrom 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.

Cystic Fibrosis below the Diaphragm: Abdominal Findings in Adult Patients

Cystic fibrosis (CF) is the most common lethal autosomal recessive disease in the white population. Mutation of the CF transmembrane conductance regulator gene on chromosome 7 results in production of abnormally viscous mucus and secretions in the lungs of patients with CF. A similar pathologic process occurs in the gastrointestinal tract, pancreas, and hepatobiliary system. Inspissated mucus causes luminal obstruction and resultant clinical and radiologic complications associated with the disease process. Pancreatic involvement can result in exocrine and endocrine insufficiency, pancreatic atrophy, fatty replacement, or lipomatous pseudohypertrophy. Acute and chronic pancreatitis, pancreatic calcification, cysts, and cystosis also occur. Hepatic manifestations include hepatic steatosis, focal biliary and multilobular cirrhosis, and portal hypertension. Biliary complications include cholelithiasis, microgallbladder, and sclerosing cholangitis. The entire digestive tract can be involved. Distal ileal obstruction syndrome, intussusception, appendicitis, chronic constipation, colonic wall thickening, fibrosing colonopathy, pneumatosis intestinalis, gastroesophageal reflux, and peptic ulcer disease have been described. Renal manifestations include nephrolithiasis and secondary amyloidosis. The educational objectives of this review are to reveal the abdominal manifestations of CF to facilitate focused analysis of cross-sectional imaging in adult patients. Life expectancy in patients with CF continues to improve because of a combination of aggressive antibiotic treatment, improved emphasis on nutrition and physiotherapy, and development of promising new CF transmembrane conductance regulator modulators. As lung function and survival improve, extrapulmonary conditions, including hepatic and gastrointestinal malignancy, will be an increasing cause of morbidity and mortality. Awareness of the expected abdominal manifestations of CF may assist radiologists in identifying acute inflammatory or neoplastic conditions. (©)RSNA, 2015.

Impact of magnetic resonance enterography in the management of small bowel Crohn's disease.

Introduction Magnetic resonance enterography (MRE) is a relatively new imaging modality that involves small bowel distension with orally administered fluid. Few studies have assessed its impact on patient management. Aim The aim of this study was to determine whether MRE influenced the management of patients with established small bowel Crohn’s disease (CD). Materials and methods From a prospectively maintained database of patients with inflammatory bowel disease, we identified patients with small bowel CD who underwent MRE between January 2007 and December 2010. The results of the MRE and subsequent changes in patient management within 1 month were evaluated. Results Thirty women and 27 men with CD were included. Seven patients (12%) had a normal MRE. Forty-two of 57 (74%) patients had a change in management, and 41/50 (82%) patients with an abnormal MRE had changes in management (P<0.0008). After MRE, 20/42 (47%) patients had surgery and 22/42 (53%) had changes in medical treatment. Patients with stricturing disease had more surgical intervention (P=0.02), and patients with active disease on MRE had more medical intervention (P=0.0001). Patients with two or more abnormalities on MRE had more surgery compared with medical therapy (P=0.02). Conclusion The majority of patients with small bowel CD had a change in management as a result of the MRE. Because of its high clinical impact on patient management, MRE should become one of the preferred methods of small bowel evaluation in CD. Specific MRE findings may help to stratify treatment options, however, further work is required to validate this.

Mass lesions in chronic pancreatitis: benign or malignant? An “evidence-based practice” approach

The diagnosis of a pancreatic mass lesion in the presence of chronic pancreatitis can be extremely challenging. At the same time, a high level of certainty about the diagnosis is necessary for appropriate management planning. The aim of this study was to establish current best evidence about which imaging methods reliably differentiate a benign from a malignant lesion, and show how that evidence is best applied. A diagnostic algorithm based on Bayesian analysis is proposed.

Videoconferencing of a national program for residents on evidence-based practice: early performance evaluation.

PURPOSE The aim of this study was to evaluate the effectiveness of the medium of videoconferencing for the delivery of a course for radiology residents in practice-based learning (PBL), including evidence-based practice, at centers geographically separated from the principal teaching site. MATERIALS AND METHODS Twenty-one participants (second-year radiology residents) at 8 centers in a radiology training program were included. The course in PBL was delivered over 16 weekly 1-hour sessions. There were 8 local education site coordinators (staff radiologists), who had completed an intensive 1-day course at the principal teaching site. The host site was linked to the participant sites using videoconferencing technology. Course evaluation included 1) a 5-point Likert-type scale and an open-ended evaluation questionnaire midway through the course (week 8) and a summation questionnaire after its completion (week 16) and 2) a consultation forum held during the penultimate session. The data responses to the questionnaires were entered in a spreadsheet, and the data were analyzed. Qualitative data were manually coded and analyzed for common themes. Descriptive statistical analyses were performed. RESULTS Eighty-five percent of evaluation questionnaires and 53% of summation questionnaires were returned. The overall satisfaction of the participants with course content was high, with median rating of 4 on the 5-point scale. All participants agreed that videoconferencing as a medium did not hinder adequate discussion among centers and worked well as an interactive teaching method (median, 4). Local coordinators were satisfied with local technical support and training (median, 4), and overall, the module was rated highly, with ratings of 4 from both residents and local coordinators. Seventy-one percent of residents and 86% of local coordinators reported that they would have been unable to participate in the course without videoconferencing. All participants completed the course requirements satisfactorily. The overall rating of audio quality was good (median, 4), but there was dissatisfaction with the quality of the visual aids used. Comments reflected a desire for a shorter, more condensed course; improvement of the quality of visual aids; and more emphasis on research appraisal. CONCLUSION Although videoconferencing is a valuable educational tool and works well as a didactic teaching method, challenges with interactive discussion between centers require further exploration. This technology allows the inclusion of trainers and trainees who may otherwise be unable to participate. In multicenter programs, this can be fundamental to the feasibility and sustainability of educational programs in newer competencies, for which a lack of a critical mass of educators and students can be problematic for individual centers.