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Helen M Fenlon

Publications and source records attributed to Helen M Fenlon.

10 recordsLinked to original sources

Colonic surveillance by CT colonography using axial images only.

Patients at increased risk of colon cancer require strict colon surveillance. Our objective was to establish the efficacy of 2D axial CT colonography as a surveillance test when performed in routine clinical practice. Eighty-two patients at increased risk of colon cancer underwent CT colonography followed by conventional colonoscopy on the same morning. CT colonography studies were performed on a four-ring multidetector CT scanner (100 mAs, 120 kVp, 4 x 2.5 collimation) and were interpreted by two radiologists using 2D axial images only. Results were correlated with findings at colonoscopy. Note was made of subsequent histology reports from polypectomy specimens. A total of 52 polyps were detected at colonoscopy. Using 2D axial images alone, with no recourse to 2D multiplanar or 3D views, the sensitivity of CT colonography was 100, 33 and 19% for polyps larger than 9, 6-9 and smaller than 6 mm, respectively. Per-patient specificities were 98.8, 96 and 81.5%, respectively. Twenty-nine percent of polyps smaller than 1 cm were adenomatous and there were no histological features of severe dysplasia. CT colonography is a useful colon surveillance tool for patients at increased risk of colon cancer. It has a high specificity for identifying patients who should proceed to colonoscopy and polypectomy, while allowing further colon examination to be deferred in patients with normal studies. Using 2D axial images only, CT colonography can be performed as part of the daily CT workload, with a very low rate of referral for unnecessary colonoscopy.

Adenomatous Polyps↗

Efficacy of IV Buscopan as a muscle relaxant in CT colonography.

The aim of this study was to examine the efficacy of IV Buscopan as a muscle relaxant in CT colonography in terms of colonic distension and polyp detection, and to determine its particular efficacy in patients with diverticular disease. Seventy-three consecutive patients were randomised to receive IV Buscopan or no muscle relaxant prior to CT colonography. CT colonography was performed using a Siemens Somatom 4-detector multislice CT scanner. The following parameters were recorded: degree of colonic distension using a 4-point scale; diagnostic adequacy of colonic distension; presence or absence of diverticular disease; and presence of colonic polyps. Accuracy of polyp detection was assessed using subsequent conventional colonoscopy as a gold standard. There was no significant difference between the two groups in the number of segments that were deemed to be optimally or adequately distended (p=0.37). Although IV Buscopan did improve distension of certain segments, this effect was not sufficient to improve the number of diagnostically adequate studies in the Buscopan group (p=0.14). In patients with diverticular disease, IV Buscopan did not have any significant effect on segments affected by diverticulosis but was associated with an improvement in distension of more proximal segments. There was no significant difference between the two groups in terms of polyp detection (p=0.34). The addition of prone scanning to supine scanning was found to be the most useful technique for maximising colonic distension. Intravenous Buscopan at CT colonography does not improve the overall adequacy of colonic distension nor the accuracy of polyp detection. In patients with sigmoid diverticular disease IV Buscopan improves distension of more proximal colonic segments and may be useful in selected cases, but our results do not support its routine use for CT colonography.

Adult↗

Virtual colonoscopy.

Computerized tomographic colonography (CT colonography) is a new, non-invasive technique that has been developed over the last few years; it looks at the large bowel in detail. In this chapter we look at how the examination is performed and we consider how the images are displayed. We describe the normal features of the colon, as seen using this technique, as well as the features of common pathological conditions. We will discuss screening for colorectal cancer and the performance of CT colonography; we compare the latter with other procedures currently employed in the screening and diagnosis of colorectal pathology. We consider the difficulties in interpreting these CT colonographic images and look at ways to overcome such difficulties. Finally we discuss future developments of this exciting, new technique.

Colon↗

Informatics in radiology (infoRAD): portable toolkit for providing straightforward access to medical image data.

Computer-aided analysis of medical images usually involves the development of custom software applications that interpret, process, and ultimately display medical image data. The interpretation stage involves decoding the image data and presenting them to the application developer for further processing. A toolkit has been created specifically for interpreting medical image data; it thus acts as a platform for development of medical imaging applications. The toolkit, which is referred to as NeatMed, is intended to reduce development time by eliminating the need for the application developer to deal directly with medical image data. NeatMed was implemented by using Java, a programming language with a range of attractive features including ease of use, extensive support material, and portability. NeatMed was developed specifically for use in a research environment. Straightforward to use and well documented, it is intended as an alternative to commercially available medical imaging toolkits. NeatMed currently provides support for the Digital Imaging and Communications in Medicine and Analyze medical image file formats. Support material including sample source code is available via the Internet; links to related resources are also provided. Most important, NeatMed is freely available and its continuing development is motivated by requests and suggestions from end users.

Confidentiality↗

Cystic duct remnant and the 'post-cholecystectomy syndrome'.

Post-cholecystectomy syndrome refers to a wide spectrum of conditions that pose a challenging diagnostic dilemma. Cystic duct remnant, defined as a residual duct greater than 1 cm in length, may, in the presence of stones, cause post-cholecystectomy syndrome. In this report, 4 patients with post-cholecystectomy syndrome due to cystic duct remnant are described. All underwent laparoscopic cholecystectomy and one was converted to open. The patients presented with pain 10 months to 9 years post-cholecystectomy and investigations demonstrated cystic duct remnant. All patients underwent successful resection with resolution of symptoms. In this era of laparoscopic surgery, where surgery favors a long cystic duct remnant, we should be aware of cystic duct stones as a possible cause of postcholecystectomy syndrome. This report highlights magnetic resonance cholangiopancreatography as the optimal method for evaluating the biliary tract in these cases.

Adult↗