Primary Research In Diagnosis Of Intracranial Aneu-rysms Among DSA,3D-CTA

PurposeConventional angiography generally selective intracranial digital subtraction angiography (DSA) , has been the criterion standard for the detection and characterization of intracranial aneurysms. This high resolution translates into relatively high sensitivity and specificity for aneurysm detection with a reported 90% -95% and 5% -10% false negative rate. The false negative rate is generally due not to limitations of specific resolution but to physical limitations of the angiography equipment that may make it difficult to obtain the optimal projection need to detect some intracranial aneurysms. In the other cases, it is not possible to know a priori which is the specific projection that will render findings. DSA has several addition disadvantages, including the high skill level that is required to perform invasiveness requiring artierial.CT angiography ( CTA) is a comparatively new noninvasive image technique. Images can be safely obtained by a trained technologist without the need for arterial paneture or eatheter manipulation . CTA is not associated with significant patient risks. CTA data can be viewed from unlimited projection in both 2Dand 3D modes, facilitating the task of aneurysm detection. CTA has been reported to be the only study perform before surgery in a significant number of cases and has been shown to reveal aneurysms when DSA results are negative. Others question the usefulness of CTA in detection of small aneurysms, generally defined in the literature as measuring <5mm.If a technique is to serve as a noninvasive replacement for DSA in the detection of aneurysms , the sensitivity and specificity of that technique for aneurysms should indefine to or higher than those of DSA , our purpose was to evalu-ate the usefulness of CTA for patients with aneurysms by using optimized acquisition.Materials and methodsBetween 2003 - 2005 a total of 48 patients underwent CTA and DSA for suspected or known aneurysms. Criteria for inclusion in the study required both CTA and DSA studies. If DSA was found to positive and CTA negative ,the patients also had to undergo surgery (coiling or clipping) for inclusion in the stud-y. Data were gathered and analyzed with approval of the CMU. All CTA studies were performed using a helical technique with routine clinical GE hi - speed . All patients were positioned supine . DSA consisted of three - or four vessel, multiple projection biplane angiography performed by neuradiologist using by Seldinger technique. Patients with positive CTA and DSA results or surgically proven aneurysms served as ture positives. CTA false negatives were defined as negative, CTA results in cases with aneurysm found by surgery or by using DSA, CTA false positive were defined as positive , CTA results in cases in which DSA or surgery were negative for aneurysms.ResultCTA prospectively detected 51 aneurysms in 51 of 54. Three patient were negative by CTA were detected by 2D and 3D DSA, one patient was detected by only 3D DSA was negative by 2D DSA and CTA, and 44 patients were underwent surgery ( coiling and clipping) , 50 aneurysms were conformed by DSA . Two aneurysms found by CTA were revealed by 2D DSA. Two aneurysms found by CTA were not revealed by 3D DSA . Data show that the smallest aneurysms is 1.7 mm, the biggest is 20.5 mm . One patient was negative by CTA and DSA...