Serdar Geyik

Hacettepe University, Engüri, Ankara, Turkey

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Publications (44)97.01 Total impact

  • Journal of vascular and interventional neurology 11/2014; 7(4):6-7.
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    ABSTRACT: Spinal intramedullary arteriovenous malformations are uncommon and a challenging type of neurosurgical entities. They are rarely located to cervical segment. On the other hand, although hemangiomas are relatively common bone tumors, cervical involvement is again rare and clinically significant ones are infrequent.
    European Spine Journal 10/2014; 24(1). DOI:10.1007/s00586-014-3620-4 · 2.47 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE:The Pipeline Embolization Device was reported to be safe and effective in the treatment of sidewall aneurysms, preserving the patency of the vessels covered by the construct. However, to date, the safety and efficacy of this device in treating bifurcation aneurysms remains unknown. We report our preliminary experience with the use of the Pipeline Embolization Device in the management of MCA aneurysms located at the bifurcations, including mid- and long-term follow-up data.MATERIALS AND METHODS:Wide-neck MCA aneurysms, which give rise to a bifurcating or distal branch in which other endovascular techniques are thought to be unfeasible or more risky, were included. Data including demographics, aneurysm features, antiplatelet therapy, complications, and angiographic follow-up results for up to 30 months were recorded.RESULTS:Twenty-five aneurysms located at the MCA bifurcation (n = 21) or distal (n = 4) were treated. Of these, 22 were small and 3 were large. A single device was used in all but 2. No deaths occurred in the series. All patients had at least 1 control angiographic study, 21 of which were DSA (3-30 months), which showed that 12 of the rising branches were patent whereas 6 were filling in reduced caliber and 3 were occluded asymptomatically. According to the last angiographic follow-up, complete occlusion was revealed in 21 of 25 aneurysms (84%).CONCLUSIONS:The Pipeline Embolization Device provides a safe and effective treatment alternative for wide-neck MCA aneurysms that give rise to a bifurcating or distal branch when other endovascular techniques are thought to be unfeasible or more risky.
    American Journal of Neuroradiology 09/2013; 35(3). DOI:10.3174/ajnr.A3692 · 3.68 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE:Stent-assisted coil embolization has become one of the most preferred techniques in the treatment of wide-neck intracranial aneurysms; however, long-term patency and safety of the self-expanding neurostents and their role in durability of the endovascular treatment has remained ambiguous. We sought to retrospectively examine the long-term results of self-expanding stent usage in conjunction with coil embolization in treatment of wide-neck cerebral aneurysms.MATERIALS AND METHODS:We coiled 500 wide-neck cerebral aneurysms with different types of self-expanding neurostent assistance in 468 patients. Patient and aneurysm characteristics, pharmacologic therapy protocol, complications, and initial occlusion grades were analyzed. Patients underwent angiographic follow-up at 6 months to 7 years after treatment. DSA or MRA images of all patients were analyzed to assess the occlusion rate of aneurysms and patency of the parent artery.RESULTS:Enterprise (n = 340), Solitaire (n = 98), Wingspan (n = 41), LEO (n = 16), and Neuroform (n = 5) stent systems were used in this series. Stent-related thromboembolic events occurred in 21 patients and intraoperative rupture occurred in 4 patients. Initially, complete occlusion was achieved in 42.2% of the aneurysms, and, according to the last follow-up data, the rate had progressed to 90.8%. Recanalization rate at 6 months was 8%, whereas the late recanalization rate was 2%.CONCLUSIONS:The use of stents in endovascular treatment provides high rates of complete occlusion and low rates of recurrence at a long-term follow-up study.
    American Journal of Neuroradiology 07/2013; 34(11). DOI:10.3174/ajnr.A3574 · 3.68 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE:The goal of endovascular treatment of cerebral bifurcation aneurysms is to achieve safe coiling of the sac along with preserving patency of the diverging branches. Our purpose was evaluate procedural safety and efficacy as well as the long-term durability of endovascular treatment of bifurcation aneurysms with double stent-assisted coiling.MATERIALS AND METHODS:One hundred eighty-one consecutive patients with bifurcation aneurysms were included in this series. Technical failure occurred in 3 aneurysms (1.5%); 188 patients with 193 aneurysms treated with double stent-assisted coiling were retrospectively evaluated; 113 aneurysms were located at middle cerebral artery bifurcation, 42 at the anterior communicating artery, 22 at the basilar artery bifurcation, and the remaining 16 at the internal carotid artery bifurcation; 132 were small (<10 mm), 56 were large (10-25 mm), and 5 were giant (>25 mm).RESULTS:The technical success rate of double-stent application was 98.5% (193 aneurysms). In total, there were 5 procedural complications with an associated rate of 2.7%, one of which led to death (0.5%). Delayed ischemic stroke occurred in 2 patients (1.1%). Overall, permanent morbidity occurred in 2 patients, with associated rate of 1.1%. Follow-up was obtained in 186 aneurysms (96.4%), and recanalization occurred in 4 aneurysms (2.2%). In subgroup analysis, the recanalization rate was 3.8% for large aneurysms and 40% for giant aneurysms. No recanalization occurred in small aneurysms.CONCLUSIONS:Dual stent-assisted coiling of cerebral aneurysms is a feasible and safe procedure. It may offer a curative solution with long-term durability for treatment of wide-neck small and large aneurysms.
    American Journal of Neuroradiology 03/2013; 34(9). DOI:10.3174/ajnr.A3464 · 3.68 Impact Factor
  • Neurological Sciences 02/2013; 34(10). DOI:10.1007/s10072-013-1318-8 · 1.50 Impact Factor
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    ABSTRACT: Flow-diverting devices now offer a new treatment alternative for cerebral aneurysms. We present the results of a large single-center series of patients treated with the PED, including long-term follow-up. Between November 2008 and September 2011, sidewall aneurysms with a wide neck (≥4 mm) or unfavorable dome-neck ratio (≤1.5); large/giant, fusiform, dissecting, blisterlike, and recurrent sidewall aneurysms; aneurysms at difficult angles; and aneurysms in which a branch was originating directly from the sac were treated with the PED. Patients were premedicated with dual antiplatelet medications. Data, including demographics, aneurysm features, clinical presentation, complications, results, and follow-up information, for up to 2 years are presented. Two hundred fifty-one aneurysms in 191 patients were treated. Of these, 96 (38.3%) were large or giant (≥10 mm). In 34/251 (13.5%), PEDs were used for retreatment. Adjunctive coiling was performed in 11 aneurysms (2.1%). The mean number of devices per aneurysm was 1.3. One aneurysm ruptured in the fourth month posttreatment (0.5%), and symptomatic in-construct stenosis was detected in 1 patient (0.5%) treated with percutaneous transarterial angioplasty. Any event rate was 27/191 (14.1%), with a permanent morbidity of 1% and mortality of 0.5%. Control angiography was available in 182 (95.3%) patients with 239 (95.2%) aneurysms. In 121 aneurysms (48.2%), 1- to 2-year control angiography was available. The aneurysm occlusion rate was 91.2% in 6 months, increasing to 94.6%. Use of the PED is safe, efficacious, and durable in cerebral aneurysm treatment, with low morbidity-mortality and high occlusion rates as confirmed with mid- to long-term control angiography.
    American Journal of Neuroradiology 07/2012; 33(8):1436-46. DOI:10.3174/ajnr.A3246 · 3.68 Impact Factor
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    ABSTRACT: Carotid-cavernous aneurysm accounts for 2-9% of all intracranial aneurysms. The rupture of carotid-cavernous aneurysm is usually caused by a trauma. Nevertheless, spontaneous rupture may rarely be encountered. Here, we report a term pregnant woman who was diagnosed to have a spontaneous carotid-cavernous fistula due to carotid-cavernous aneurysm rupture and was managed with detachable balloon and coils immediately after cesarean section.
    Journal of Obstetrics and Gynaecology Research 12/2011; 38(2):427-30. DOI:10.1111/j.1447-0756.2011.01703.x · 0.93 Impact Factor
  • Journal of Neurosurgery 07/2011; 115(1):77-77. · 3.23 Impact Factor
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    ABSTRACT: Stent-assisted endovascular treatment and flow diversion techniques are increasingly used for the management of wide-neck intracranial aneurysms. We report our initial clinical experience using a new flow diversion technique for the endovascular management of bifurcation aneurysms. Eight bifurcation aneurysms were treated by placing 2 stents in Y-configuration with no accompanying endosaccular packing. This treatment technique aimed at flow diversion was selected in these cases because 1) the aneurysm was giant and causing mass effect, 2) the emanating branches were incorporated within the sac, or 3) the aneurysm was too small. Aneurysms were located at middle cerebral (5 aneurysms) and basilar artery bifurcations (3 aneurysms). Five aneurysms were small, 1 was large, and 2 were partially thrombosed giant. Closed-cell stents were used in all Y-stent placement procedures. In all aneurysms, both stents could be placed at the intended locations without any procedural complication. Follow-up angiograms obtained at 3 months to 2 years demonstrated that all stents were patent except for one with asymptomatic P1 occlusion. Complete occlusion with remodelled bifurcation was observed in all middle cerebral artery bifurcation aneurysms and the large basilar tip aneurysm. Residual filling despite reduction in size was observed in both of the partially thrombosed giant aneurysms at 2-year and 3-month follow-up angiograms, respectively. Flow diversion with double stent placement in Y-configuration provided successful and stable aneurysm occlusion. The technical and clinical results achieved are highly encouraging that this technique may contribute to the endovascular treatment of these complex bifurcation aneurysms.
    American Journal of Neuroradiology 04/2011; 32(7):1262-8. DOI:10.3174/ajnr.A2475 · 3.68 Impact Factor
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    ABSTRACT: The purpose of this study was to present the authors' clinical experience and long-term angiographic and clinical follow-up results in 350 patients with brain arteriovenous malformations (AVMs) treated using prolonged intranidal Onyx injection with a very slow "staged" reflux technique described by the authors. Three hundred and fifty consecutive patients with brain AVMs treated using Onyx between 1999 and 2008 and in whom definitive status for endovascular treatment was reached are presented. There were 206 (59%) male and 144 (41%) female patients, with a mean age of 34 years. There were 607 endovascular sessions performed. Onyx was the only agent used for intranidal injections in all patients, but in 42 patients high-concentration N-butyl cyanoacrylate glue was used adjunctively to close high-flow direct arteriovenous intra- or perinidal fistulas, or when a feeding vessel or nidus perforation and/or dissection occurred. Angiographically confirmed obliteration was achieved in 179 patients (51%) with only endovascular treatment; 1 patient died due to intracranial hemorrhage after the treatment. Twenty-two patients underwent resection, and 136 patients were sent to radiosurgery after endovascular treatment. In 4 patients embolization therapy was discontinued, and 5 additional patients refused the suggested complementary surgery. In all 178 surviving patients who had angiographically confirmed AVM obliteration by embolization alone, 1-8 years of control angiography (mean 47 months) confirmed stable obliteration, except for 2 patients in whom a very small recruitment was noted in the 1st year on control angiography studies, despite initial apparent total obliteration (recanalization rate 1.1%). In the entire series, 5 patients died; the mortality rate was 1.4%. The permanent morbidity rate was 7.1%. With the prolonged intranidal injection technique described herein, Onyx allows the practitioner to achieve higher rates of anatomical cures compared with the cure rates obtained previously with other embolic agents. More importantly, due to this technique's much more effective intranidal penetration, it allows high-grade AVMs to be made radiosurgically treatable in a group of patients for whom there has been no treatment alternative.
    Journal of Neurosurgery 04/2011; 115(1):78-88. DOI:10.3171/2011.2.JNS09830 · 3.15 Impact Factor
  • Journal of Neurosurgery 04/2011; 114(4):943-943. · 3.23 Impact Factor
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    ABSTRACT: Incomplete initial occlusion rates and relatively less long-term durability remain as major problems of endovascular treatment of cerebral aneurysms. Stent-assisted coiling is a well-established current solution to overcome these problems. Double-stent treatment with a Y-configuration has been previously reported to improve the application of coiling to wide-neck bifurcation aneurysms. Herein, a novel technique of X-configured stent-assisted coiling for treatment of wide-neck and complex AcomA aneurysms is described.
    American Journal of Neuroradiology 06/2010; 32(6):E113-7. DOI:10.3174/ajnr.A2111 · 3.68 Impact Factor
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    ABSTRACT: The purpose of this paper was to present the safety, efficacy, and clinical/angiographic follow-up results of HyperForm balloon-assisted endosaccular coil occlusion of distal anterior circulation bifurcation aneurysms. Over a 7-year period, the authors treated 864 middle cerebral artery, distal anterior cerebral artery bifurcation, and anterior communicating artery aneurysms by means of coil embolization with HyperForm balloon assistance in 800 patients. In 37 aneurysms, 2 HyperForm balloons were used simultaneously for remodeling. The overall mortality rate was 7.1%, including 1.4% procedural mortality. Various neurological deficits were present at discharge in 8.9% of the patients, and 4.4% had permanent disabling morbidity 6 months posttreatment (modified Rankin Scale score ≥ 2). Thromboembolic complications developed during the treatment of 15 aneurysms (1.7%) causing morbidity or mortality in 10 cases (1.3%). There were 14 intraoperative perforations (1.6%). In all 14 cases, the HyperForm balloon saved patients from severe bleeding. The perforation led to morbidity or mortality in 3 cases (0.4%); there were no negative consequences in 11. There were 726 patients with 757 aneurysms (87.6%) available for follow-up. Control angiograms were obtained at 6 months in 386 patients, at 1 year in 267, and at 2 years in 104, revealing an 82% complete obliteration rate according to the most recent follow-up angiograms. The satisfactory results obtained in this experience demonstrate that HyperForm balloon remodeling provides strong benefits for the endovascular management of middle cerebral, anterior cerebral, and anterior communicating artery aneurysms without increasing the risk of treatment. Not only does this technique allow for the safe treatment of these aneurysms, but it also expands the indications of endovascular treatment to include aneurysms that otherwise cannot be treated with simple coil embolization.
    Journal of Neurosurgery 05/2010; 114(4):944-53. DOI:10.3171/2010.3.JNS081131 · 3.15 Impact Factor
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    ABSTRACT: The primary goal of this matched-pair analysis was to evaluate the durability of the treatment results with Cerecyte coils in comparison with that of bare platinum coils in terms of angiographic occlusion rates at follow-up. Eighty aneurysms treated with Cerecyte coils were included in this study to carry out a matched-pair analysis. Every aneurysm treated with Cerecyte coils was matched with an aneurysm treated with bare platinum coils. Matching of the aneurysms was done according to the aneurysm size, location, neck size, initial occlusion grade, and clinical presentation. The initial treatment results were similar in both groups as part of a matching protocol. Subgroup analysis revealed a significant difference in the durability of occlusion in aneurysms that showed Raymond Class I obliteration on follow-up angiograms (69 [86.2%] in the Cerecyte group vs 51 [63.8%] in the control group, p = 0.002). Further thrombosis to Raymond Class I occlusions was higher in the Cerecyte group (17 [77.3%] of 22 vs 8 [36.4%] of 22 aneurysms). Cerecyte coils provide further thrombosis and more durable results than bare platinum coils following coil embolization of cerebral aneurysms.
    Journal of Neurosurgery 10/2009; 112(4):709-13. DOI:10.3171/2009.8.JNS081372 · 3.15 Impact Factor
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    ABSTRACT: The WingSpan stent is a new self-expandable neurovascular stent designed for endovascular treatment of intracranial atheromatous lesions. The authors report their experience with the use of this stent for the endovascular treatment of intracranial aneurysms. Thirty-seven patients with 40 wide-necked intracranial aneurysms were treated using the WingSpan stent. Twenty-two aneurysms (55%) were small and 18 (45%) were large or giant. In all but 4 aneurysms, embolization was completed by packing the aneurysm sac with platinum coils. In 4 dissecting aneurysms that were fusiform or too small and wide necked to be catheterized, the stent was used alone. In these cases, the stent bridged the aneurysm neck to allow for flow redirection and the potential stent-induced endothelization effect. Follow-up angiograms obtained in 3 of 4 aneurysms, treated with only stent placement, demonstrated aneurysmal thrombosis and parent artery remodeling in 2 patients and moderate decrease in size in 1. Follow-up angiography obtained at 6 months to 1 year in 31 aneurysms after stent-supported coil embolization demonstrated complete occlusion in 23 aneurysms (74.2%) with a progressive thrombosis rate of 66.7% (10 of 15 aneurysms), and a recanalization rate of 16.1%. In treating wide-necked intracranial aneurysms, the WingSpan Stent System is very flexible, secure, and effective. Its delivery system is very easy and exact in that it exerts higher outward radial force, thus providing an excellent conformability and a strong scaffold to hold the coils in place. It may offer an effective treatment when used alone in some fusiform or very wide-necked, small dissecting aneurysms in which other surgical or endovascular treatment strategies are not deemed feasible.
    Journal of Neurosurgery 10/2008; 109(3):445-53. DOI:10.3171/JNS/2008/109/9/0445 · 3.23 Impact Factor
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    ABSTRACT: Craniofacial venous vascular malformations cause severe cosmetic problems and yet these lesions are not candidates for transcatheter embolisation owing to the lack of arterial feeders. The purpose of this study was to evaluate the effectiveness of pre-operative embolisation of these lesions with N-butyl 2-cyanoacrylate (NBCA) via direct puncture. Between September 2003 and April 2006, 13 patients (7 female; age range, 6-64 years; mean, 16.7 years) were embolised with direct puncture and injection of NBCA. All of the patients were referred from plastic surgery with an operational plan. Angiography performed in all patients showed no or little arterial staining. NBCA diluted with iodized oil at a ratio of 1:6 (18%) was injected via a percutaneously placed 21 gauge needle. Complete embolisation was achieved in 8 patients and partial embolisation in the remaining 5. A total of 18 sessions of embolisation were performed on 13 patients. Nine patients underwent only one embolisation session, three patients underwent two sessions and only one patient underwent three sessions. The mean volume of NBCA used per session was 5.8 ml, ranging from 1-12 ml. All patients underwent a successful surgical resection to improve cosmetic disfigurement within 10-15 days after the embolisation procedure. Mean follow-up time was 22 months. One patient experienced skin necrosis on her nose after embolisation. No other complications related to the procedure were observed. In conclusion, pre-operative NBCA embolisation with direct puncture is a safe and easy procedure. It can increase the success of the surgical treatment of these lesions.
    The British journal of radiology 10/2008; 81(972):935-9. DOI:10.1259/bjr/66893325 · 2.02 Impact Factor
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    ABSTRACT: The Cerecyte coils were developed to improve long-term stability of embolized cerebral aneurysms by producing an increased fibrous reaction over the neck of the aneurysms. We report our preliminary clinical experience with mid-term follow-up. Seventy-eight consecutive patients with 84 intracranial aneurysms treated exclusively with Cerecyte coils were included in this study. Forty-eight aneurysms were ruptured and 36 were incidental. Twenty-two aneurysms were small with (<10 mm) small neck (<4 mm) (SASN); 55 were small with wide neck (>or=4 mm) (SAWN); six were large (10-25 mm) (L); and one was giant (G) (>25 mm). The embolization technique was the same with that in standard bare coiling. Immediate post-procedure angiography demonstrated complete aneurysm occlusion in 69%, neck remnant in 29.8% and incomplete occlusion in 1.2%. Follow-up angiography was obtained in 80 aneurysms in a period of time ranging from 6 months to 2 years. The overall recanalization rate was 11.3%, and the re-treatment rate was 6.3%; in the subgroup analysis, recanalization rates were 4.5% in S/S; 9.8% in S/W; and 33.3% in large aneurysms. The only giant aneurysm also showed recanalization. Procedure-related morbidity and mortality rates were 2.6% and 1.3%, respectively. Our midterm results showed a relatively low rate of recurrence compared to those reported for platinum coils with morbidity and mortality rates comparable to those with standard bare platinum coils. The efficacy of Cerecyte coils in the long term will be specifically addressed by the ongoing randomized Cerecyte coil trial.
    Neuroradiology 05/2008; 50(9):787-93. DOI:10.1007/s00234-008-0399-1 · 2.37 Impact Factor
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    ABSTRACT: To determine the incidence of venous thromboembolism (VTE) after removal of retrievable inferior vena cava (IVC) filters. Retrospective study was conducted of 67 patients who underwent 72 consecutive filter retrievals at a single institution. Data collected included VTE status at the time of filter placement, anticoagulant medications at the time of filter retrieval and afterward, new or recurrent VTE after filter removal, and insertion of subsequent filters. Patient questionnaires were completed in 50 cases, chart review in all patients. At the time of filter placement, 30 patients had documented VTE, 19 had a history of treated VTE, and 23 were at risk for but had neither previous nor present VTE. Mean duration of follow-up after filter removal was 20.6 months +/- 10.9. A total of 52 patients (57 filters) received anticoagulation and/or antiplatelet medications after filter removal. There were two documented episodes of recurrent deep vein thrombosis (2.8% of filters removed), both in patients who had VTE at the time of filter placement and underwent therapeutic anticoagulation at the time of filter removal. One of these patients (1.4% of filters removed) also experienced pulmonary embolism. Of the 23 patients without VTE when the filter was placed, none developed VTE after filter removal. Four patients (5.5% of filters removed) required subsequent permanent filters, three for complications of anticoagulation, one for failure of anticoagulation. VTE was rare after removal of IVC filters, but was most likely to occur in patients who had VTE at the time of filter placement.
    Journal of Vascular and Interventional Radiology 05/2008; 19(4):504-508. DOI:10.1016/j.jvir.2007.11.016 · 2.15 Impact Factor
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    ABSTRACT: To present our experience using the Amplatzer vascular plug in various arterial and venous systems, and follow-up results. Between May 2005 and October 2006, 20 Amplatzer vascular plugs were used to achieve occlusion in 20 vessels in 12 patients (10 male, 2 female) aged between 24 and 80 years (mean age, 55 years). Localization and indications for embolotherapy were as follows: pulmonary arteriovenous malformations (n = 3; 9 vessels), internal iliac artery embolization before stent-graft repair for aortoiliac aneurysms (n = 4; 4 vessels), preoperative (right hemipelvectomy) embolization of bilateral internal iliac arteries (n = 1), bilateral internal iliac aneurysms (n = 1), large thoracic side branch of the left internal mammary artery coronary by-pass graft causing coronary steal syndrome (n = 1), closure of a transjugular intrahepatic portosystemic shunt (n = 1), and testicular vein embolization for a varicocele (n = 1). The technical success rate was 100%, with total occlusion of all the targeted vessels. Only one device was used to achieve total occlusion of the targeted vessel in all patients (device size range, 6-16 mm in diameter). No major complications occurred. Target vessel occlusion time after deployment of the Amplatzer vascular plug was 6-10 min in pulmonary arteries (mean, 7.5 min) and 10-35 min (mean, 24.4 min) in systemic arteries. Mean follow-up was 6.7 months (range, 1-18 months). Embolization with the Amplatzer vascular plug is safe, feasible, and technically simple with appropriate patient selection in various vascular territories.
    Diagnostic and interventional radiology (Ankara, Turkey) 04/2008; 14(1):35-9. · 1.43 Impact Factor