Detection Of Intracranial Aneurysms Research Articles

A priori knowledge integration for the detection of cerebral aneurysm.

The detection of intracranial aneurysms is of a paramount effect in the prevention of cerebral subarachnoid hemorrhage. We propose in this paper, a new approach to detect cerebral aneurysm in digital subtraction angiography (DSA) images by fusing several sources of knowledge. After a brief description of a priori knowledge that the expert has provided about cerebral aneurysm, we propose a system architecture including fuzzy modeling and data fusion. The results on the studied cases are very promising.

Outflow angle measurement: a simple approach for the differential diagnosis of intracranial protrusion with a branch artery arising from its top.

Magnetic resonance angiography (MRA) is an important diagnosis method for the detection of intracranial aneurysms (IAs), but it is not useful for differentiating between IA and infundibular dilatation (ID) in patients in whom imaging shows an intracranial protrusion with a branch artery at its top. The objective of this study was to introduce a new approach-measurement of the outflow angle (OA)-for differentiating between IA and ID in such cases. The study included 7 patients with a total of 9 protrusions. The protrusions were separately reviewed on MRA and DSA images. We first diagnosed the protrusions using OA approach. An OA≥90° was considered indicative of an IA and an OA<90° was considered indicative of an ID. The diagnosis by the OA method was compared with diagnosis by the gold standard-DSA. Among the 9 intracranial protrusions, 5 were IAs and 4 were IDs. The OAs of 5 IAs were all≥90°; the average OA of the 5 IAs was 115.20°. The OAs of the 4 IDs were all<90°; the average OA of the 4 IDs was 59.50°. The diagnosis results by the OA method were in agreement with DSA diagnosis in all cases. The OA method can discriminate between IA and ID in patients in whom imaging shows an intracranial protrusion with a branch artery at its top. The method is simple and convenient, and can be easily applied in clinical practice. It can be especially useful for novice neuroradiologists.

Evolution from invasive arterial puncture to a venous access for cerebral angiography: “Cath Lab to CT suite”

Background: Digital subtraction angiography (DSA) is considered as the gold standard in the evaluation of intracranial aneurysms. This study was undertaken to evaluate the effectiveness of computed tomogram angiography (CTA) in the detection and accurate characterization of intracranial aneurysms in suspected cases of nontraumatic subarachnoid hemorrhage. The importance of three‑dimensional volume rendering of the intracranial vasculature and it’s used as an aid in improving diagnostic capabilities with regards to intracranial aneurysms in multi‑detector computed tomography angiography (MDCTA), was stressed upon. This study also tried to probe whether MDCTA alone can be used in detection and treatment of intracranial aneurysms in emergency situations. Materials and Methods: Suspected cases of nontraumatic acute subarachnoid hemorrhage, over an 18 months period, underwent CTA in 16‑slice‑computed tomography suite. Fifty cases where CTA demonstrated intracranial aneurysms were studied. A set protocol of three‑dimensional reconstruction was followed. Comparison of findings of MDCTA with surgical notes was performed. DSA was done in ambiguous cases. Results: Aneurysm was confidently diagnosed by CTA in 48 cases, and further confirmed on surgery. In doubtful cases, DSA was performed and then diagnosed as aneurysm. Thus, the sensitivity of CTA is diagnosing aneurysm is 96.6%, with a specificity of 100%. Conclusions: Digital subtraction angiography is an invasive, relatively costly, procedure to be done by highly skilled personnel with serious complication rate of 1%. This can be replaced by MDCTA, which is noninvasive, cost effective and easy to perform, and DSA can be reserved for doubtful or difficult cases. Following a set protocol of three‑dimensional reconstruction helps in reducing errors.

Blob Enhancement and Visualization for Improved Intracranial Aneurysm Detection

Several researches have established that the sensitivity of visual assessment of smaller intracranial aneurysms is not satisfactory. Computer-aided diagnosis based on volume rendering of the response of blob enhancement filters may shorten visual inspection and increase detection sensitivity by directing a diagnostician to suspicious locations in cerebral vasculature. We proposed a novel blob enhancement filter based on a modified volume ratio of Hessian eigenvalues that has a more uniform response inside the blob-like structures compared to state-of-the-art filters. Because the response of proposed filter is independent of the size and intensity of structures, it is especially sensitive for detecting small blob-like structures such as aneuryms. We proposed a novel volume rendering method, which is sensitive to signal energy along the viewing ray and which visually enhances the visualization of true positives and suppresses usually sharp false positive responses. The proposed and state-of-the-art methods were quantitatively evaluated on a synthetic dataset and 42 clinical datasets of patients with aneurysms. Because of the capability to accurately enhance the aneurysm’s boundary and due to a low number of visualized false positive responses, the combined use of the proposed filter and visualization method ensures a reliable detection of (small) intracranial aneurysms.

TH‐CD‐206‐11: An Ellipsoid Convex Enhancement Filter Based Computer‐Aided Diagnostic Framework of Intracranial Aneurysms in MRA Images

Purpose:For early detections of asymptomatic intracranial aneurysms, computer aided diagnostic (CAD) frameworks of intracranial aneurysms in magnetic resonance angiography (MRA) images were developed with various enhancement filters. However, discrimination between aneurysms and false positive structures, such as bending or branching portions of vessels could still be a challenging task for the enhancement filters. Therefore, we focused on developing an ellipsoid convex enhancement (ECE) filter based CAD framework, which is capable of enhancing aneurysms while reducing the effect on bending and branching portions of vessels, for detection of intracranial aneurysm candidate.Methods:The proposed ECE filter was designed for selectively enhancing aneurysms with certain ellipsoid convex shapes, whose ratios of the shortest to longest diameters correspond to the ratio of reciprocals of the square roots of the first and third eigenvalues of Hessian matrices. This filter was applied to artificial images with Gaussian ellipsoid models and clinical MRA images of 30 patients (Male: 10, Female: 20; age: 48 to 86 years, mean: 69.2) with 31 unruptured aneurysms (longest diameter: 2.0 to 5.5 mm, mean: 3.7 mm) based on a leave‐one‐out‐by‐patient test.Results:The proposed ECE filter reduced the average contrast for false positive Gaussian ellipsoid models by 51.4%. The number of false positives per patient decreased from 41.1 to 22.8 at a sensitivity of 87% by using the ECE filter.Conclusion:The ellipsoid convex enhancement filter based CAD framework of intracranial aneurysms in MRA images would be useful by providing a higher contrast between aneurysms and false positive structures such as bending or branching portions of vessels.

Cerebral CTA with Low Tube Voltage and Low Contrast Material Volume for Detection of Intracranial Aneurysms.

Multidetector row CTA has become the primary imaging technique for detecting intracranial aneurysms. Technical progress enables the use of cerebral CTA with lower radiation doses and contrast media. We evaluated the diagnostic accuracy of 80-kV(peak) cerebral CTA with 30 mL of contrast agent for detecting intracranial aneurysms. Two hundred four patients were randomly divided into 2 groups. Patients in group A (n = 102) underwent 80-kVp CTA with 30 mL of contrast agent, while patients in group B (n = 102) underwent conventional CTA (120 kVp, 60 mL of contrast agent). All patients underwent DSA. Image quality, diagnostic accuracy, and radiation dose between the 2 groups were compared. Diagnostic image quality was obtained in 100 and 99 patients in groups A and B, respectively (P = .65). With DSA as reference standard, diagnostic accuracy on a per-aneurysm basis was 89.9% for group A and 93.9% for group B. For evaluating smaller aneurysms (<3 mm), the diagnostic accuracy of groups A and B was 86.3% and 90.8%, respectively. There was no difference in diagnostic accuracy between each CTA group and DSA (all, P > .05) or between the 2 CTA groups (all, P > .05). The effective dose in group A was reduced by 72.7% compared with group B. In detecting intracranial aneurysms with substantial radiation dose and contrast agent reduction, 80-kVp/30-mL contrast CTA provides the same diagnostic accuracy as conventional CTA.

Semi-automatic detection and segmentation algorithm of saccular aneurysms in 2D cerebral DSA images

ObjectiveTo detect and segment cerebral saccular aneurysms (CSAs) in 2D Digital Subtraction Angiography (DSA) images. Patients and methodsTen patients underwent Intra-arterial DSA procedures. Patients were injected with Iodine-containing radiopaque material. A scheme for semi-automatic detection and segmentation of intracranial aneurysms is proposed in this study. The algorithm consisted of three major image processing stages: image enhancement, image segmentation and image classification. Applied to the 2D Digital Subtraction Angiography (DSA) images, the algorithm was evaluated in 19 scene files to detect 10 CSAs. ResultsAneurysms were identified by the proposed detection and segmentation algorithm with 89.47% sensitivity and 80.95% positive predictive value (PPV) after executing the algorithm on 19 DSA images of 10 aneurysms. Results have been verified by specialized radiologists. However, 4 false positive aneurysms were detected when aneurysms’ location is at Anterior Communicating Artery (ACA). ConclusionThe suggested algorithm is a promising method for detection and segmentation of saccular aneurysms; it provides a diagnostic tool for CSAs.

Subtraction CT angiography for the detection of intracranial aneurysms: A meta-analysis.

The aim of this meta-analysis was to investigate the accuracy of subtraction computed tomography angiography (CTA) for diagnosing intracranial aneurysms. A systematic literature search up to January 1, 2013 was performed in PubMed. Two independent reviewers selected 8 studies that compared subtraction CTA with digital subtraction angiography. Data from the studies were used to construct a 2×2 contingency table on a per-patient basis in ≥5 diseased and 5 non-diseased patients, with additional data on a per-aneurysm basis. Overall, subtraction CTA had a pooled sensitivity of 99% [95% confidence interval (CI), 95-100%] and specificity of 94% (95% CI, 86-97%) for detecting and ruling out cerebral aneurysms, respectively, on a per-patient basis. On a per-aneurysm basis, the pooled sensitivity was 96% (95% CI, 90-99%), and the specificity was 91% (95% CI, 85-95%). In conclusion, subtraction CTA is a highly sensitive, specific and non-invasive method for the diagnosis and evaluation of intracranial aneurysms.

磁気共鳴血管画像における脳動脈瘤のコンピュータ支援検出と将来展望

磁気共鳴血管画像における脳動脈瘤のコンピュータ支援検出と将来展望

Detection and characterization of intracranial aneurysms: a 10-year multidetector CT angiography experience in a large center

BackgroundCT angiography (CTA) is increasingly used for the detection, characterization, and follow-up of intracranial aneurysms. A lower threshold to request a CT angiogram may render a patient population that differs...

Risk Factors Associated With the Presence of Unruptured Intracranial Aneurysms.

With the increased investigation of cerebral arteries using magnetic resonance angiography in the general population, the detection of unruptured intracranial aneurysms (UIAs) has increased. Understanding the distribution and factors associated with UIAs might be helpful for understanding the pathomechanism. Subjects who underwent magnetic resonance angiography with a health examination at the Health Screening and Promotion Center were enrolled. The incidence and risk factors of UIAs (age, sex, hypertension, diabetes mellitus, smoking, alcohol, and coronary artery disease) were investigated by comparing patients with and without UIAs. These risk factors were also investigated by the UIA location, distal internal carotid artery, anterior cerebral artery and middle cerebral artery (MCA), MCA bifurcation, anterior and posterior communicating artery, and posterior circulation. Among 187 166 subjects who received health examination, 18 954 underwent magnetic resonance angiography. Of them, 367 (1.93%) had UIAs. Age (odds ratio [OR], 1.02; P=0.003), women (OR, 2.00; P<0.001), hypertension (OR, 2.21; P<0.001), smoking (OR, 1.66; P=0.001), and coronary artery disease (OR, 0.23; P<0.001) were independently associated with the presence of UIAs. Hypertension was associated with most UIAs, except for those located at sidewalls (anterior cerebral artery and MCA). MCA aneurysms were associated with old age and smoking. Distal internal carotid artery, posterior communicating artery, and MCA-bifurcation aneurysms were associated with female sex. Anterior communicating artery aneurysms were associated with smoking and alcohol. Posterior circulation UIAs were only associated with hypertension. Coronary artery disease was negatively associated with anterior circulation aneurysms. The risk factors for UIAs differ by their location, compared with the control. Interestingly, the presence of coronary artery disease was protective against the presence of UIAs.

CT angiography in non-traumatic subarachnoid hemorrhage: the importance of arterial attenuation for the detection of intracranial aneurysms.

Computed tomography angiography (CTA) is today the primary method for the detection of intracranial aneurysms. The technique has evolved considerably during the last decade, and it is important to establish criteria for high image quality, especially with regard to improving the diagnosis of small aneurysms. To evaluate diagnostic accuracy and image quality by arterial attenuation of CTA in patients with non-traumatic subarachnoid hemorrhage (SAH). Between 2005 and 2011, CTA and digital subtraction angiography (DSA) were performed in 326 patients with non-traumatic SAH. Sensitivity and specificity for aneurysm detection were evaluated per patient, per aneurysm, and per ruptured aneurysm. The image quality of CTA was evaluated by arterial attenuation measurements (mean Hounsfield units [HU]) in the internal carotid artery (ICA). In all, 285 aneurysms in 235 patients were detected by DSA, 19 aneurysms were missed on CTA, and 223 aneurysms were classified as ruptured. In 91 patients, no aneurysm was found. Correct diagnosis with CTA was made in 28 patients with perimesencephalic hemorrhage. Sensitivity and specificity (95% confidence interval) calculated per patient were 91.6% (87.3-94.9) and 87.9% (79.8-93.6), respectively, per aneurysm 93.3% (89.7-95.9) and 88% (79.9-93.6), and per ruptured aneurysm 94.9% (91.3-97.3) and 96.7% (90.7-99.3). Arterial attenuation (in HU) in CTA revealing true positive ruptured aneurysms and true negative aneurysms (mean 535 ± 110 HU) differed significantly (P = 0.02) from false negative ruptured aneurysms (mean 424 ± 30 HU). CTA has high sensitivity and specificity for the detection of ruptured aneurysms. The sensitivity is related to arterial attenuation in the ICA.

3D bone subtraction CT angiography for the evaluation of intracranial aneurysms: a comparison study with 2D bone subtraction CT angiography and conventional non-subtracted CT angiography.

Bone subtraction computed tomography angiography (BSCTA) is better able to facilitate the detection of intracranial aneurysms adjacent to bone structures compared to conventional non-subtracted CTA (CNSCTA). However, the comparison of the diagnostic accuracy of three-dimensional (3D) and two-dimensional (2D) BSCTA and conventional CTA in evaluating intracranial aneurysms remains unclear. To evaluate whether 3D BSCTA has a superior diagnostic accuracy to those of 2D BSCTA and CNSCTA in a single center with the same instrument. Sixty-three patients received 3D BSCTA, 2D BSCTA, and NSCTA for the detection and treatment planning of suspected intracranial aneurysms. The angiography readouts were reviewed by two independent radiologists. The sensitivity of CTA in detecting aneurysm was analyzed on a per-aneurysm and per-patient basis, using 3D digital subtraction angiography (DSA) and surgical findings as the gold standard. The potential of endovascular treatment or surgical clipping was also assessed based on information provided by the CTA. A total of 66 aneurysms were detected in 54 patients. The overall sensitivity, specificity, positive, and negative predictive values of 3D BSCTA were all 100%, and these values for 2D BSCTA were 98.1%, 100%, 100%, and 90%, respectively. The total sensitivity, specificity, positive, and negative predictive values of CNSCTA were 94.4%, 100%, 100%, and 75%, respectively. Finally, 100%, 98.1%, and 85.2% patients received appropriate treatment decisions after 3D BSCTA, 2D BSCTA, and CNSCTA imaging, respectively. 3D BSCTA has a higher sensitivity for the detection of small aneurysms and aneurysms adjacent to bone compared to 2D BSCTA or CNSCTA, which were still able to obtain sufficient information for the detection of intracranial aneurysms and therapeutic decision-making.

Detection of unruptured intracranial aneurysms on noninvasive imaging. Is there still a role for digital subtraction angiography?

Background:To determine the utility of digital subtraction angiography (DSA) in patients with unruptured intracranial aneurysms (UIA) detected on noninvasive imaging, such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA). The follow-up of patients with untreated UIAs involves serial imaging; however, this diagnosis may be based on false positive (FP) results. We examined the incidence of FPs in our institutional series.Methods:DSAs performed at our institution from January 2011 to June 2014 were retrospectively reviewed and patients referred with UIA detected on noninvasive imaging were selected. Clinical presentation as well as aneurysm location, size, and number reported on DSA and noninvasive imaging were assessed.Results:Two hundred and eighty six patients (mean age 56.8 years, female 74.8%) with a total of 355 UIA were included. Thirty-one patients had a symptomatic presentation. Analysis per patient showed the pooled FP rate of noninvasive imaging was 15%. MRA FP was 13% (22/171) and CTA FP was 18% (22/120). FP increased significantly with aneurysm size < 3.5 mm on MRA (P < 0.001) and <4.0 mm on CTA (P = 0.01). Mean aneurysm size among symptomatic patients was significantly larger (P < 0.001) as compared to the incidental group (17.8 vs. 7.7 mm). No location was significantly susceptible to false detection of aneurysms.Conclusion:DSA detection of FP UIA diagnosed on noninvasive imaging is significantly higher for aneurysms <4.0 mm. Accurate diagnosis with DSA may eliminate the need for further follow-up and its associated negative psychological and economic effects. Within the limitations of this retrospective study, we conclude that DSA has a diagnostic role in small aneurysms detected on noninvasive imaging.

Influence of selective photon shield combined with sinogram affirmed iterative reconstruction on image quality and radiation dose of dual-energy CT angiography for the diagnosis of intracranial aneurysms

Objective To investigate the influence of selective photon shield combined with sinogram affirmed iterative reconstruction(SAFIRE) on image quality and radiation dose of dual-energy CTA for the diagnosis of intracranial aneurysms. Methods The study retrospectively analyzed 80 patients with spontaneous subarachnoid hemorrhage, who were diangosed having intracranial aneurysms by three-dimensional DSA and surgery and underwent cerebral CTA examination. According to CTA scanning method, the patients were divided into conventional group and experimental group (n=40 for each). All patients underwent head CTA in dual energy mode with selective photon shield (SPS) technology. The scanning protocols of conventional group were tube voltages 80 kV and sn 140 kV, tube currents 300 mAs and 150 mAs, filtered back projection (FBP) reconstruction. The scanning protocols of experimental group were tube voltages 80 kV, sn 140 kV, tube currents 200 mAs, 100 mAs, SAFIRE reconstruction. Objective image quality evaluation indexes included the average CT value of all parts (occipital lobe, the anterior cerebral artery, middle cerebral artery and posterior cerebral artery), the background noise, the signal-to-noise ratio (SNR) and contrast to noise ratio (CNR), and subjective image quality was also assessed. Radiation dose was recorded. With 3D DSA or operation findings as gold standard, coincidence rate of intracranial aneurysm detection was calculated both in experimental group and conventional group. Objective image quality evaluation index and radiation dose both in conventional group and experimental group were compared with two independent two-sample t test, subjective image scores with non parameter test of independent samples. Results The noise of occipital lobe, the anterior cerebral artery, middle cerebral artery and posterior cerebral artery were (5.34±1.22), (39.94±15.96), (39.94±15.96) and (23.17± 5.51) HU in conventional group, (4.44 ± 1.08), (24.91 ± 9.36), (35.03 ± 13.65) and (20.61 ± 5.08) in experimental group (the value of t test were 2.508,3.742,2.788 and 2.563, P 0.05). Image quality scores of the conventional group and experimental group were (4.86± 0.07) and (4.67±0.21) without statistical difference (Z=- 0.443,P=0.621). CTDIvol and ED were (20.61 ± 1.07) mGy and (0.79 ± 0.04) mSv in conventional group and (13.59 ± 1.27) mGy and (0.54 ± 0.06) mSv in experimental group (the value of t test were 24.039 and 15.813, P<0.01). With 3D DSA or operation findings as gold standard, intracranial aneurysm diagnosis coincidence of experimental group was 100.0% (29/29), while coincidence rate of conventional group was 96.0% (25/26). Conclusion SPS combined with SAFIRE techniques applied in dual energy CTA for the diagnosis of intracranial aneurysms could improve the quality of CT image and reduce the radiation dosage and have a high diagnosis accuracy. Key words: Intracranial aneurysm; Tomography, X-ray computed; Radiation dosage; Image quality

Diagnostic accuracy of contrast enhancement MRI versus CTA in diagnosis of intracranial aneurysm in patients with non-traumatic subarachnoid hemorrhage

Aim of the studyThe most common cause of spontaneous SAH is the rupture of cerebral aneurysm. So it is very important to exclude it from circulation as soon as possible using endovascular therapy. The aim was to determine whether contrast enhancement magnetic resonance angiography (CEMRA) is preferable to computed tomography angiography (CTA) in detection of intracranial aneurysm in patients presenting with non-traumatic subarachnoid hemorrhage (SAH). Patients and methodsTwenty-five patients who presented with non-traumatic SAH underwent CEMRA and CTA for detection of aneurysms. Digital subtraction angiography (DSA) was used as standard of reference. ResultsCEMRA and CTA were done for all patients. A total of 22 aneurysms were detected in 25 patients. 15 patients with single aneurysm, 2 patients with two aneurysms, one patient with 3 aneurysms and in 7 patients no aneurysm was found. CEMRA and CTA angiograms were interpreted for the detection of aneurysms, site and size. ConclusionThe diagnostic performance of CEMRA does not significantly differ from that of CTA in patients presenting with SAH.

Non-invasive diagnosis of intracranial aneurysms.

Patients need to be examined for intracranial aneurysms if they have had a subarachnoid hemorrhage. The preferred technique in this situation is CT angiography. Screening can be done for familial forms or for elastic tissue disorders, for which the first line investigation is magnetic resonance angiography. These non-invasive methods have now taken over from conventional angiography that was reserved for the pretreatment phase. A good technical knowledge of these imaging methods, their artifacts and misleading images enables reliable detection of intracranial aneurysms and for an accurate report to be returned to clinicians.

Detection and characterization of unruptured intracranial aneurysms: Comparison of 3 T MRA and DSA

To compare magnetic resonance angiography (MRA) at 3 Tesla (3T) and digital subtraction angiography (DSA) for the detection and characterization of unruptured intracranial aneurysms (UIA). This study has been approved by our local ethical committee. From February to August 2010, 40 consecutive patients with UIA contemporarily underwent MRA at 3T including time-of-flight (TOF-MRA) and contrast enhanced (CE-MRA) techniques and DSA. MR images were independently reviewed by 3 radiologists and DSA images were reviewed by 2 radiologists together. Interobserver and intertechnique agreements were assessed for aneurysm detection and characterization including maximal diameter, neck width and the presence of a bleb or a branch arising from the sac. DS angiography revealed 56 aneurysms. Mean sensitivity and positive predictive value of MRA were 91.4% and 93.4% respectively. For UIA < 3 mm and those ≥ 3 mm, MRA had a mean sensitivity of 74.1% and 100% respectively. Intertechnique and interobserver agreements were substantial for the measurement of UIA maximal diameter (mean κ, 0.607 and 0.601 respectively) and were moderate and fair for neck width measurement respectively (mean κ, 0.456 and 0.285 respectively). For bleb detection, intertechnique and interobserver agreements were fair and slight respectively (mean κ, 0.312 and 0.116 respectively) whereas both were slight for detection of branches arising from the sac (mean κ, 0.151 and 0.070 respectively). MR angiography at 3T has a high sensitivity for the detection of UIA. However, it remains significantly inferior to DSA for morphological characterization of UIA.

64-section multidetector CT angiography for evaluation of intracranial aneurysms: comparison with 3D rotational angiography

To assess the diagnostic performance of 64-section computed tomography angiography (CTA) for detection of cerebral aneurysms by comparison with the new gold standard three-dimensional (3D) digital subtraction angiography (DSA). A total of 128 patients who underwent both 64-section CTA and 3D DSA for suspected intracranial aneurysms were included. The location, size, and shape of the aneurysm were assessed and compared with 3D DSA results. The sensitivity, specificity, positive and negative predictive values of 64-section CTA were calculated by using 3D DSA as reference standard. According to the reference standard, a total of 145 aneurysms were detected at 3D DSA in 118 patients. Of these 145 aneurysms, 64-section CTA detected 139 aneurysms in 118 patients. The sensitivity of CTA for detection of aneurysm was 95.8% on a per-aneurysm basis. All missed aneurysms were non-causative very small aneurysms in patients harboring multiple aneurysms. On a per-patient basis, the sensitivity, specificity, positive and negative predictive values were 100%. Compared with the new gold standard 3D DSA, 64-section CTA offers high sensitivity and specificity for detection of intracranial aneurysms. It could be readily used as a screening imaging method for detection of intracranial aneurysms.

Comparison of 64 Dedector Cranial CT Angiography with Intra-Arterial DSA For Detection of Intracranial Aneurysms

The purpose of our study was to compare findings of 64 detector cranial computed tomographic angiography (CTA) and convention al digital subtraction angiography (DSA) mainly in patients with acute subarachnoid hemorrhage (SAH) headache and diplopia. Between March 2007 and May 2009, 65 consecutive patients were admitted with clinical symptoms and signs of intracranial aneurysm. 44 of 67 detected aneurysms were confirmed during surgery or endovascular embolization. DSA was performed in the 3 days after CTA. CT angiograms and conventional angiographies were studied by two radiologists, who performed aneurysm detection and characterisation of morphological features. Using CTA and DSA, we detected 67 aneurysms in 50 patients. 15 patients did not have any aneurysms in both DSA and CTA. There was no difference between the two modalities in the number of the detected aneurysms. But two aneurysms were falsely located before surgery with CTA. They were located in posterior communicating artery (PcoA) but, had been thought to be located at the internal carotid artery supraclinoid segment at CTA. CTA has an equal sensitivity as DSA in the detection of intracranial aneurysms. It has 100% detection rate in anterior communicating artery and middle cerebral artery bifurcation aneurysms, but aneurysms at some locations, like the ones at PcoA, were hard to detect with CTA. DSA preserves its diagnostic value for detection of posterior circulation aneurysms.