Preoperative CT in patients with surgically resectable pancreatic adenocarcinoma: does the time interval between CT and surgery affect survival?

PURPOSE: The preoperative imaging-to-surgery time interval (ISI) influences the risk of unexpected progression (UP) found at surgery for pancreatic adenocarcinoma. We aimed to assess whether ISI influences disease recurrence and/or survival. METHODS AND MATERIALS: A single-institution, ethics board-approved retrospective analysis of all patients who underwent attempted resection of pancreatic (PDAC) or periampullary adenocarcinoma (AmpAC) between 1st January 2010 and 31st December 2015 was performed. All patients underwent preoperative abdominal computed tomography (CT). Exclusion criteria were borderline resectable disease and neoadjuvant chemo/radiotherapy. Patients were followed up until 30th June 2016. The population was divided into ISI ≥/<25 days. Kaplan-Meier and Cox regression survival analyses were performed. RESULTS: 239 patients underwent surgical exploration. UP was found in 29 (12.1%) and these patients had longer ISI (median 46 vs. 29 days, p < 0.05). When intention-to-treat analysis was performed, there was no difference in overall survival (OS) between patients with ISI ≥/<25. In those who underwent resection, ISI did not influence disease-free survival (DFS) or OS for PDAC (n = 174). For AmpAC (n = 36), ISI ≥ 25 days was associated with longer OS (p < 0.05) but did not influence DFS. Longer ISI was independently associated with improved OS on regression analysis for AmpAC. CONCLUSION: Performing surgery for resectable pancreatic adenocarcinoma within 25 days of abdominal CT reduces the chance of UP but does not confer a survival benefit. For those who undergo resection of AmpAC, a longer ISI was associated with longer OS. This probably represents a more biologically indolent disease in this cohort.

Is diffusion-weighted MRI sufficient for follow-up of neuroendocrine tumour liver metastases?

AIM: To assess if diffusion-weighted imaging (DWI) alone could be used for follow-up of neuroendocrine hepatic metastases. MATERIAL AND METHODS: This was a retrospective study, approved by the institutional review board. Twenty-two patients with neuroendocrine liver metastases who had undergone more than one liver magnetic resonance imaging (MRI) examination, (including DWI and using hepatocyte-specific contrast medium) were evaluated. Up to five metastases were measured at baseline and at each subsequent examination. The reference standard measurement was performed on the hepatocyte phase by one reader. Three independent readers separately measured the same lesions on DWI sequences alone, blinded to other sequences, and recorded the presence of any new lesions. RESULTS: The longest diameters of 317 liver metastases (91 on 22 baseline examinations and a further 226 measurements on follow-up) were measured on the reference standard by one reader and on three b-values by three other readers. The mean difference between DWI measurements and the reference standard measurement was between 0.01-0.08 cm over the nine reader/b-value combinations. Based on the width of the Bland and Altman interval containing approximately 95% of the differences between the reader observation and the mean of reference standard and DWI measurement, the narrowest interval over the nine reader/b-value combinations was -0.6 to +0.7 cm and the widest was -0.9 to 1 cm. In the evaluation of overall response using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria, the weighted kappa statistic was between 0.49 and 0.86, indicating moderate-to-good agreement between the reference standard and DWI. CONCLUSION: The visualisation and measurement of hepatic metastases using DWI alone are within acceptable limits for clinical use, allowing the use of this rapid technique to restage hepatic disease in patients with neuroendocrine metastases.

Comparative Effectiveness of Imaging Modalities for the Diagnosis of Intestinal Obstruction in Neonates and Infants:: A Critically Appraised Topic.

RATIONALE AND OBJECTIVES: The purpose of this study was to critically appraise and compare the diagnostic performance of imaging modalities that are used for the diagnosis of upper and lower gastrointestinal (GI) tract obstruction in neonates and infants. METHODS: A focused clinical question was constructed and the literature was searched using the patient, intervention, comparison, outcome method comparing radiography, upper GI contrast study, and ultrasound in the detection of upper GI tract obstruction such as duodenal atresia and stenosis, jejunal and ileal atresia, and malrotation and volvulus. The same methods were used to compare radiography and contrast enema in the detection of lower GI tract obstruction such as meconium plug syndrome, meconium ileus, Hirschsprung disease, and imperforate anus. Retrieved articles were appraised and assigned a level of evidence based on the Oxford University Centre for Evidence-Based Medicine hierarchy of validity for diagnostic studies. RESULTS: There were no sensitivities/specificities available for the imaging diagnosis of duodenal atresia or stenosis, jejunal or ileal atresias, meconium plug, and meconium ileus or for the use of cross-table lateral radiography for the diagnosis of rectal pouch distance from skin in imperforate anus. The retrieved sensitivity for the detection of malrotation on upper GI contrast study is 96%, and the sensitivity for the diagnosis of midgut volvulus on upper GI contrast study is 79%. The retrieved sensitivity and specificity for the detection of malrotation with volvulus on ultrasound were 89% and 92%, respectively. The retrieved sensitivity and specificity for the detection of Hirschsprung disease on contrast enema were 70% and 83%, respectively. The retrieved sensitivity of invertogram for the diagnosis of rectal pouch distance from skin in imperforate anus is 27%. The retrieved sensitivities of perineal ultrasound and colostography for the diagnosis of rectal pouch distance from skin in imperforate anus were 86% and 100%, respectively. CONCLUSIONS: There is limited evidence for the imaging diagnosis of duodenal atresia and stenosis, jejunal and ileal atresias, meconium plug, meconium ileus, and imperforate anus, with recommended practice based mainly on low-quality evidence or expert opinion. The available evidence supports the use of upper GI contrast study for the diagnosis of malrotation and volvulus, with ultrasound as an adjunct to diagnosis. Contrast enema is useful in the investigation of suspected Hirschsprung disease, but a negative study does not outrule the condition. Colostography is the investigation of choice for the work-up of infants with complex anorectal malformations before definitive surgical repair.

Which is the best current guideline for the diagnosis and management of cystic pancreatic neoplasms? An appraisal using evidence-based practice methods.

BACKGROUND AND AIM: Cystic pancreatic neoplasms (CPNs) are an increasingly diagnosed entity. Their heterogeneity poses complex diagnostic and management challenges. Despite frequently encountering these entities, particularly in the context of the increased imaging of patients in modern medicine, doctors have to rely on incomplete and ambiguous published literature. The aim of this project was to review the guidelines relating to CPNs using evidence-based practice (EBP) methods. METHODS: A search of both the primary and secondary literature was performed. Five sets of guidelines were identified which were then methodologically appraised by the AGREE II instrument, a validated and widely utilised tool for guideline development assessment. RESULTS: The 2014 'Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms' were found to be the most methodologically sound guidelines, on the basis of both the overall score and average weighted domain score. CONCLUSIONS: The current best guidelines were identified. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument can be used for retrospective review of published guidelines or as a roadmap for guideline-writing groups. All guidelines found were methodologically limited. Further longitudinal/prospective studies are required to improve the level of evidence. KEY POINTS: • Cystic pancreatic neoplasms (CPNs) are an increasingly encountered entity in modern medicine. • Clinical uncertainty remains with regard to optimal diagnostic and management strategies. • The Italian consensus guidelines for cystic pancreatic neoplasms are currently the best guidelines.

Subclassification of small bowel Crohn's disease using magnetic resonance enterography: a review using evidence-based medicine methodology.

Magnetic resonance enterography (MRE) has a growing role in imaging small bowel Crohn's disease (SBCD), both in diagnosis and assessment of treatment response. Certain SBCD phenotypes respond well to biologic therapy and others require surgery; MRE has an expanding role in triaging these patients. In this review, we evaluate the MRE signs that subclassify SBCD using evidence-based medicine (EBM) methodology and provide a structured approach to MRE interpretation.

Pancreaticoduodenectomy: expected post-operative anatomy and complications.

Pancreaticoduodenectomy is a complex, high-risk surgical procedure performed for tumours of the pancreatic head and other periampullary structures. The rate of perioperative mortality has decreased in the past number of years but perioperative morbidity remains high. This pictorial review illustrates expected findings in early and late post-operative periods, including mimickers of pathology. It aims to familiarize radiologists with the imaging appearances of common and unusual post-operative complications. These are classified into early non-vascular complications such as delayed gastric emptying, post-operative collections, pancreatic fistulae and bilomas; late non-vascular complications, for example, biliary strictures and hepatic abscesses; and vascular complications including haemorrhage and ischaemia. Options for minimally invasive image-guided management of vascular and non-vascular complications are discussed. Familiarity with normal anatomic findings is essential in order to distinguish expected post-operative change from surgical complications or recurrent disease. This review summarizes the normal and abnormal radiological findings following pancreaticoduodenectomy.

Diagnostic performance of MDCT, PET/CT and gadoxetic acid (Primovist(®))-enhanced MRI in patients with colorectal liver metastases being considered for hepatic resection: initial experience in a single centre.

PURPOSE: To compare the relative diagnostic performance of MDCT, PET/CT and Primovist-enhanced MRI (P-MRI) in the pre-resection work-up of colorectal cancer (CRC) liver metastases. METHOD AND MATERIALS: This was a retrospective study of consecutive referrals for CRC liver metastases. All patients had MDCT, PET/CT and P-MRI examinations within 3 months of each other. They were divided into 2 groups: resected and unresected. Patients in the resected group underwent liver resection within 3 months of the imaging studies. In the unresected group, patients were unresectable by imaging criteria or are awaiting surgery. Standard of reference (SOR) was intra-operative ultrasound findings and pathology for the resected group. Intermodality comparison was the SOR for the unresected group. Number of lesions identified by each imaging modality for each patient was recorded. Sensitivity (95% CI) and PPV were calculated for each imaging modality in the resected group. RESULTS: There were 19 patients in the resected group and 11 patients in the unresected group. The sensitivity (96%) and PPV (0.91) of P-MRI were both superior to that of MDCT (P = 0.0009) and PET/CT (P = 0.0003). Intermodality comparison showed that P-MRI detected more lesions than MDCT and PET/CT. CONCLUSION: The sensitivity and PPV of P-MRI was superior to that of MDCT and PET/CT. P-MRI probably has the most added value if used after MDCT and PET/CT in patients still considered eligible for liver resection.

CT colonography and transient bacteraemia: implications for antibiotic prophylaxis.

OBJECTIVES: To determine the prevalence of transient bacteraemia after CT colonography (CTC). METHODS: Blood cultures were obtained at 5, 10 and 15 min after CTC from 100 consecutive consenting patients. Blood samples were cultured in both aerobic and anaerobic media and positive blood culture samples were analysed by a microbiologist. RESULTS: Blood culture samples were positive for growth in sixteen patients. All positive blood culture samples were confirmed skin contaminants. There were no cases of significant bacteraemia. The estimated significant bacteraemia rate as a result of CTC is 0-3.7%, based on 95% confidence intervals around extreme results using Wilson's score method. CONCLUSIONS: American Heart Association and National Institute for Clinical Excellence guidelines advise that antibiotic prophylaxis before lower gastrointestinal endoscopy is not indicated in patients with at risk cardiac lesions (ARCL) as the risk of a transient bacteraemia leading to infective endocarditis is low. These data show that the prevalence of transient bacteraemia after CTC is also low. It follows that patients with ARCL do not require antibiotic prophylaxis before CTC.

Plain X-ray and computed tomography of the orbit in cases and suspected cases of intraocular foreign body.

AIM: To evaluate the roles of plain X-ray and computed tomography (CT) orbital imaging in cases and suspected cases of intraocular foreign body (IOFB). METHODS: Retrospective review of clinical and radiological data relating to 204 consecutive cases and suspected cases of IOFB.SettingRoyal Victoria Eye and Ear Hospital, Dublin, Ireland. RESULTS: Plain X-rays were performed in the absence of clinically evident ocular penetration in 177 (87%) cases, and no IOFB was demonstrated in any of these radiographs. Twenty-seven (13%) plain X-ray radiographs were obtained in the presence of clinically evident ocular penetration, and an IOFB was clinically visible in 19 (70%) of these cases. CT scans were undertaken in 21 (10%) of the 204 patients. Of these CT images, 9 (43%) and 12 (57%) were undertaken in the absence and presence of clinically evident ocular penetration, respectively. None (0%) and all (100%) of the CT scans obtained in the absence and presence of clinically evident ocular penetration demonstrated an IOFB, respectively. CONCLUSION: Plain X-ray and CT orbital imaging are non-contributory in the absence of clinically evident ocular penetration. In the presence of clinically evident ocular penetration, and where an IOFB is clinically visible, plain X-ray orbital radiography may have a role in excluding multiple IOFBs. In the presence of clinically evident ocular penetration, but where an IOFB is not clinically visible, CT orbital imaging remains the investigation of choice, and the role of pre-CT plain X-ray orbital radiography, as recommended by the guidelines of the Royal College of Radiologists, merits re-evaluation.

Achievable outcomes in the management of proximal cholangiocarcinoma: an update prepared using "evidence-based practice" techniques.

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.

Minimal preparation computed tomography instead of barium enema/colonoscopy for suspected colon cancer in frail elderly patients: an outcome analysis study.

AIM: To evaluate the efficacy of minimal preparation computed tomography (MPCT) in diagnosing clinically significant colonic tumours in frail, elderly patients. MATERIALS AND METHODS: A prospective study was performed in a group of consecutively referred, frail, elderly patients with symptoms or signs of anaemia, pain, rectal bleeding or weight loss. The MPCT protocol consisted of 1.5 l Gastrografin 1% diluted with sterile water administered during the 48 h before the procedure with no bowel preparation or administration of intravenous contrast medium. Eight millimetre contiguous scans through the abdomen and pelvis were performed. The scans were double-reported by two gastrointestinal radiologists as showing definite (>90% certain), probable (50-90% certain), possible (<50% certain) neoplasm or normal. Where observers disagreed the more pessimistic of the two reports was accepted. The gold standard was clinical outcome at 1 year with positive end-points defined as (1) histological confirmation of CRC, (2) clinical presentation consistent with CRC without histological confirmation if the patient was too unwell for biopsy/surgery, and (3) death directly attributable to colorectal carcinoma (CRC) with/without post-mortem confirmation. Negative end-points were defined as patients with no clinical, radiological or post-mortem findings of CRC. Patients were followed for 1 year or until one of the above end-points were met. RESULTS: Seventy-two patients were included (mean age 81; range 62-93). One-year follow-up was completed in 94.4% (n=68). Mortality from all causes was 33% (n=24). Five histologically proven tumours were diagnosed with CT and there were two probable false-negatives. Results were analysed twice: assuming all CT lesions test positive and considering "possible" lesions test negative [brackets] (95% confidence intervals): sensitivity 0.88 (0.47-1.0) [0.75 (0.35-0.97)], specificity 0.47 (0.34-0.6) [0.87 (0.75-0.94)], positive predictive value 0.18 [0.43], negative predictive value 0.97 [0.96], positive likelihood ratio result 1.6 [5.63], negative likelihood ratio result 0.27 [0.29], kappa 0.31 [0.43]. Tumour prevalence was 12%. A graph of conditional probabilities was generated and analysed. A variety of unsuspected pathology was also found in this series of patients. CONCLUSIONS: MPCT should be double-reported, at least initially. "Possible" lesions should be ignored. Analysis of the graph of conditional probability applied to a group of frail, elderly patients with a high mortality from all causes (33% in our study) suggests: (1) if MPCT suggests definite or probable carcinoma, regardless of the pre-test probability, the post-test probability is high enough to warrant further action, (2) frail, elderly patients with a low pre-test probability for CRC and a negative MPCT should not have further investigation, (3) frail, elderly patients with a higher pre-test probability of CRC (such as those presenting with rectal bleeding) and a negative MPCT should have either double contrast barium enema (DCBE) or colonoscopy as further investigations or be followed clinically for 3-6 months. MPCT was acceptable to patients and clinicians and may reveal significant extra-colonic pathology.

The value of digital personal dosemeters in angiography/interventional radiology: preliminary experience.

New interventional procedures tend to involve longer screening times than were hitherto used in radiology. A careful audit of technique and shielding facilities needs to be performed to ensure that patient and operator doses are optimised. This paper explores the use of digital dosemeters to evaluate operator dose. Equipment related parameters, e.g. screening time, dose-area-product (DAP) readings, were not found to be strongly correlated to operator dose. The real time display on the electronic dosemeter is a non-intrusive indicator of the efficacy of operator protection strategies.

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.

Applying 'technology assessment' and 'evidence based medicine' theory to interventional radiology. Part 1: Suggestions for the phased evaluation of new procedures.

AIM: To compare and contrast interventional radiology (IR) clinical and research practices with the technology assessment and evidence-based medicine (EBM) paradigms and make suggestions for the phased evaluation of new IR procedures. MATERIALS AND METHODS: Course literature of the Association of University Radiologists' 'Basic Technology Assessment for Radiologists' course and the McMaster University Health Information Research Unit's 'How to Teach Evidence-Based Medicine 1999' course were used to identify major publications in each discipline. A computer search was performed to seek other relevant literature. A model of traditional development of IR procedures was developed. Suggestions for the phased evaluation of IR procedures were derived. RESULTS: As in diagnostic radiology, several levels of progressively stronger IR study design can be described and related to EBM 'levels of evidence'. These range from case reports and case series through case-control and cohort studies to randomized controlled trials (RCTs). The major weakness in the existing IR literature is the predominance of small, uncontrolled, case series. Randomized controlled trials are likely to provide the best possible evidence of effectiveness. They are expensive and randomization is sometimes unethical or impractical. Case-control and cohort studies have been under-utilized. Evidence-based medicine indices of benefit and harm have not yet been applied in IR and may have clinical advantages over traditional statistical methods. A literature search (10 years) using MeSH terms 'radiology, interventional' and 'efficacy' yielded 30 papers. Combining 'radiology, interventional' and 'evidence-based medicine' yielded no papers. Comparative searches substituting the term 'diagnostic imaging' for 'radiology, interventional' yielded 4883 and 62 papers, respectively. CONCLUSION: Principles of technology assessment and EBM can be applied to the investigation of new IR procedures. A tool is needed to simplify the application of EBM analytic methods. Better education in research methods is needed to raise the levels of evidence provided by the bulk of IR research and allow new procedures to be introduced into practice appropriately. Malone, D. E. & MacEneaney, P. M. (2000). Clinical Radiology55, 929-937.

Applying 'evidence-based medicine' theory to interventional radiology. Part 2: a spreadsheet for swift assessment of procedural benefit and harm.

AIM: To design a spreadsheet program to analyse interventional radiology (IR) data rapidly produced in local research or reported in the literature using 'evidence-based medicine' (EBM) parameters of treatment benefit and harm. MATERIALS AND METHODS: Microsoft Excel(TM)was used. The spreadsheet consists of three worksheets. The first shows the 'Levels of Evidence and Grades of Recommendations' that can be assigned to therapeutic studies as defined by the Oxford Centre for EBM. The second and third worksheets facilitate the EBM assessment of therapeutic benefit and harm. Validity criteria are described. These include the assessment of the adequacy of sample size in the detection of possible procedural complications. A contingency (2 x 2) table for raw data on comparative outcomes in treated patients and controls has been incorporated. Formulae for EBM calculations are related to these numerators and denominators in the spreadsheet. The parameters calculated are benefit - relative risk reduction, absolute risk reduction, number needed to treat (NNT). Harm - relative risk, relative odds, number needed to harm (NNH). Ninety-five per cent confidence intervals are calculated for all these indices. The results change automatically when the data in the therapeutic outcome cells are changed. A final section allows the user to correct the NNT or NNH in their application to individual patients. RESULTS: This spreadsheet can be used on desktop and palmtop computers. The MS Excel(TM)version can be downloaded via the Internet from the URL ftp://radiography.com/pub/TxHarm00.xls. CONCLUSION: A spreadsheet is useful for the rapid analysis of the clinical benefit and harm from IR procedures.