MR Angiography with Existing Modalities in the Initial Diagnosis of Peripheral Arterial Disease - Essay Example

MR Angiography with Existing Modalities in the Initial Diagnosis of Peripheral Arterial Disease. A Critical Review Huegli, Aschwanden, Bongartz, Jaeger, et.al. (2006). Intraarterial MR Angiography and DSA in Patients with Peripheral Arterial Occlusive Disease: Prospective Comparison. Radiology 239(3). 901 The general purpose of this study was to evaluate the effectiveness of MR against the standard which is DSA in determining patients with peripheral arterial occlusive disease. The knowledge is available through studies that have been done and this study will be used to compare to those. The outcomes are realistic and there are studies that support the outcomes One that is an example was completed by Winterer, Schaefer, and Uhrmeister (2002) in which they contrasted the MR angiography against the DSA and had similar outcomes. The researchers involved were all a part of the Departments of Radiology at the University Hospital of Basei, each was an MD with the exception of one that is a PhD. There are no notations found indicating where funding is from but the study is ethics approved There are some important issues that could be solved if the MR stands up against the DSA. These according to Huegli et.al. (2006), are, "absence of x-ray exposure, lack of nephrotoxic iodinated contrast media administration and absence of allergic reaction, three dimensional vascular delineation and excellent bone and tissue contrast." This is an important problem to solve and there were no unrealistic demands on participants nor were there any ethical issues with consenting or treatment There was a wide range of research done though not all of the research appears to be directly related to the study. The search strategy is not noted in this study and a short search from this writer turned up three contrasting studies within a short amount of time that are not included in the research list. The research is not critically appraised and there is little conflicting evidence though there were also no documented limits in the literature review. The sample used included all patients that met the criteria determined over a 6 month period for one clinic. These were 20 patients, ages 38-86 who were consecutively enrolled in the study. This was a consecutive group so there were no biases and there was nothing random about the sampling. It is troubling that there is not mention of consent but there is ethics committee approval. Individuals were not tracked well, however, there were twenty patients in the beginning and there were many more stenosis and occlusions so many of them had more than one. The study design was OK but a randomized control study might have been more effective with a larger sampling size and a control group. Data was collected from recorded results from each patients testing Results were well linked to the previous questions asked. They were also well broken down and comparative figures done. There did not seem to be any lost data. The conclusions that were made in this case were related to the results of the study as the study does show positive results. The ethics of this study were not well defined or discussed. This is in comparison to Rohrl, Kinz and Katja (2009) study in which there was a much stronger discussion about privacy and the fact that the patients were ask by someone else prior to consenting whether they would even want to be involved in the study and in Grijalba, and Esandi (2010) in which the reading was done by someone not involved in the study. Andreisek G, Pfammatter T, Goepfert K, etal. (2007). Peripheral Arteries in Diabetic Patients: Standard Bolus-Chase and Time-resolved MR Angiography. Radiology 242(2). The purpose of this second study is similar to the purpose of the first. They felt the need to determine if MR angiography would work as well as DSA which has been the standard. The reasons are important as there is a need to find a less invasive study with less allergic response to conduct this diagnosis with. This makes the problem significant as an allergic reaction in a diabetic patient might very well cause the very thing that is trying to be diagnosed. Written informed consent was obtained from each patient and in each case the patient had been ask ahead of time so they could make their decision before going in for consent. This is much better documented than in the previous study. In this case, research questions are well developed and stem from the hypothesis. The literature search seems to be well carried out with good coverage of the issue. There is no critical review of the literature in this case. Two of the studies that were found for comparison using a CINAHL based study are also on this list of literature. There is no clear description of how the search was done in the study. Consecutive diabetic patients were consented for the study. There were 31. There appeared to be not coercion and they were all regular patients of this particular clinic. The sampling of course was not random and could present bias however, this seems to be overcome by the fact that a second reader was used that was not involved in the study and a Wilcoxon signed rank test was used to determine if there was a significant difference in the readings. The research ethics committee did review and approve the study. All of the participants did show up as accounted for at the beginning and the end of the study. The study design as a consecutive study works in this case but again, would have been more convincing if it had been a randomized study with a control group as was the study performed by Schaper, Franssen, and Buijberts (2000) in which there were two study groups and a control group showing approximately the same results. The results of this study showed that TRICKS depicted peripheral vascular disease of the lower extremity better than that of the MR or the DSA. This was well related to their question and the results seemed to reflect a good answer to the problem. The conclusions were well related to the results and the recommendation to make this diagnostic procedure of choice was well documented as was the results by Krause, Pabst, and Kenn (2004). Leiner T, Kessels A, Nelemans P. etal.(2005). Peripheral Arterial Disease: Comparison of Color Duplex US and Contrast-enhanced MR Angiography for Diagnosis. Radiology. 235:699- 708. The purpose of this study was a little different in the fact that it is a prospective study to determine if the color duplex ultrasonography MR and MR angiographic finding for PAD are comparable. Funders are not noted and potential outcomes are realistic and could define diagnostic testing that should be used at first level. Most of the diagnosis of PAD is done by history and physical and patients often end up in surgery when they have intermittent claudication. Approximately 100,000 people undergo endoscopic or surgical treatment annually according to Leiner, Kessels, and Nelemans. This makes this a significant problem as this disease often happens with diabetics and the numbers of diabetics in this country are increasing rapidly (Kreitner, Kalden, Neufang, 2009). The literature search is not very inclusive as there are only 33 studies listed for the whole paper and there is no mention of how the search was done or any critical analysis of the literature. The sample here is better than in the other two studies. There were 249 patients included in this study and each had at least one lesion. 152 underwent DSA and the others color contrast MR Angiography. The patients were randomized to the two studies and consenting was done ahead of time. The study was also approved by the institutional review board. 295 patients were actually referred and for various reasons some chose not to be part of the study. There was clear evidence of the informed consent as well as the ethics review. The design for the study was good in the fact that it was randomized but it would have been even better if it had had a control group which this one did not. The results were quadratic rated and the McNemar test was used to show interobserver agreement before results were considered in the data so data was pretty tightly controlled. The results in this case showed that" the comparison between contrast-enhanced MR angiography and duplex US provide evidence that contrast enhanced MR angiography is more sensitive and specific for diagnosis and preinterventional work up of PAD" (Leiner, Kessels, Nelemans, 2005). This is directly connected to the original question and shows some answer to the problem, although admitted by the researchers, there may be a need for more follow-up on this study. This is in contrast to a study done by Waugh & Sacharias (1992) in which there were more complications noted with MRA than with DSA and therefore the opposite suggestion was made. This research was well developed and reviewed by ethics providing a second reviewer and a contrast between the two reviewers assuring that the results were correct before they were added to the data. There was a significant strength in the note that there were patients who chose not to do the study and the fact that all of the patients were consented prior to the study taking place. Works Cited Andreisek G, Pfammatter T, & Goepfert K. (2007). Peripheral arteries in diabetic patients: standard bolus-chase and time resolved MR angiography. Radiology 242 (2). Grijalba F, & Esandi M. (2010). Comparison of gadofosveset-enhanced three-dimensional magnetic resonance angiography with digital subtraction angiography for lower- extremity peripheral arterial occlusive disease. Acta Radilogica 51(6). Huegli, R, Aschwanden M, & Bongartz G. (2006). Intra-arterial MR Angiography and DSA in Patients with Peripheral Arterial Occlusive Disease: Prospective Comparison. Radiology. 239(3). Krause UJ, Pabst T, Kenn W, Wittenbert G. (2004). Time resolved contrast enhanced magnetic resonance angiography of the lower extremity. Angiology. 55. 119-125. Kreitner KF, Kalden P, Neufang A. et.al. (2009). Diabetes and peripheral arterial occlusive disease prospective comparison of contrast enhanced three-dimensional MR angiography with conventional digital subtraction angiography. AJR Am J Roentgenol. 174. Leiner T, Kessels A, Nelemans P. (2005). Peripheral arterial disease: comparison of color duplex US and contrast-enhanced MR Angiography for Diagnosis. Radiology. 235: 699-708. Rohrl B, Kunz R, & Oberholzer K, et.al. (2009). Gadofosveset-enhanced MR angiography of the pedal arteries in patients with diabetes mellitus and comparison with selective intra-arterial DSA. European Radiology.19(12).2993-3001. Schaper NC, Franssen MH, Huijberts MS. Peripheral vascular disease and type 2 diabetes mellitus. Diabetes Metabolism Research. 16 (1): 11-15. Waugh HR, Sacharias N.(1996). Arteriographic complications in the DSA era. Radiology 182:243-246. Winterer J, Schaefer O, Uhrmeister P. et.al. (2002). Contrast enhanced MR angiography in the assessment of relevant stenoses in occlusive disease of the pelvic and lower limb arteries: diagnostic value of a two-step examination protocol in comparison to conventional DSA. European Journal of Radiology. 41(2). 153. Read More