[Multi-slice CT angiography in the diagnosis and characterization of cerebral aneurysms]
To assess the diagnostic accuracy of multislice computed tomography angiography in the detection and characterization of cerebral aneurysms. Multislice CT angiography and DSA were performed in 41 patients suspected to have intracranial aneurysms. A volume rendering method was used to produce three-dimensional CT angiograms. The diameter, location, neck and branching pattern of aneurysms were evaluated with CT angiography and DSA and compared with each other. Of 41 patients, DSA depicted 44 aneurysms in 33 patients. Multislice CT angiography depicted 44 aneurysms in 34 patients. One aneurysm demonstrated with DSA was not detected at multislice CT angiography. One aneurysm demonstrated with multislice CT angiography and confirmed at surgery was not demonstrated with DSA. There was no false positive aneurysm in multislice CT angiography. There were 4 aneurysms smaller than 3 mm and multislice CT angiography demonstrated all these aneurysms. In 9 aneurysms, the neck and branching pattern could only be shown with multislice CT angiography. Sensitivity and specificity of multislice CT angiography were 97.7% and 87.5%, respectively. Multislice CT angiography has a high sensitivity and specificity in the diagnosis of intracranial aneurysms and is superior to DSA in the delineation of the aneurysm neck and branching pattern. Multislice technology with submillimeter collimation improves the detection of small aneurysms and the delineation of the neck of the aneurysms.
[Show abstract] [Hide abstract] ABSTRACT: A potential hazard in midline posterior fossa craniectomy may be the injury of vertebral artery. That's why vertebral artery evaluation prior to surgery may prevent dangerous complications. Advancements in multidetector computed tomography (MDCT) have provided detailed demonstration of the vertebral artery at the craniocervical junction and its relationships with atlas and axis. We aimed to define the normal anatomic relationship of the V2 and V3 part of the vertebral artery on MDCT. In total, 33 patients underwent MDCT angiography scan with suspected cranial aneurysm. V2 and V3 segments of vertebral artery were evaluated. Eight measurements (B, C, D, E, G, H, X, and Y line) were taken from MDCT images. For B and C, a line initially passing through the body of axis and spinous process and determining the midline was formed. Then, the vertical distance of vertebral artery from the level of transverse foramen of axis and loop to this midline was measured. For D and G, the vertical distance of vertebral artery to the midline from the upper and lower margin levels of transverse foramen of atlas was measured after a line establishing the midline passing through the anterior and posterior tubercles of atlas was drawn first. For E, transverse diameter of vertebral artery was measured at the loop level of V2 segment. For H, the vertical distance at the point where vertebral artery entered dura in the line passing from the midline of foramen magnum at anterior-posterior plane was measured. For X and Y, two different points of horizontal part of the vertebral artery were determined. One of these two points was the lateral one which was the origin of the horizontal part in the transverse foramen, the other was the intersection point on atlas. Average distances for both sides from transverse foramen of the axis, the loop of axoatlantal part and the lower border of the atlas of the vertebral artery to the midline were 20.97 mm on the right, 22.29 mm on the left; 27.19 mm on the right, 28.34 mm on the left; and 25.75 mm on the right and 27.21 mm on the left, respectively. Average distances for both sides from the upper border of the atlas, and at its penetration through dura were 27.40 mm on the right, 28.94 mm on the left; and 10.90 mm on the right and 10.93 mm on the left, respectively. Distances between spinous process and intersection of vertebral artery with horizontal part were 35.79 mm on the right and 36.63 mm on the left laterally, and 22.27 mm on the right and 22.62 mm on the left medially. MDCT angiography is a powerful test to demonstrate the vasculature of the head and neck. Bony structures and adjacent vessel morphology can be evaluated by this technique. The evaluation of craniocervical region prior to surgery with MDCT may be helpful to avoid intraoperative vascular injuries.
- "CTA is a rapidly developing technology with great potential. Postprocessing techniques for CTA include maximal intensity projection (MIP), multiplanar reconstruction (MPR), and volume rendering (VR) that are done at the three-dimensional (3D) workstation   . "
- [Show abstract] [Hide abstract] ABSTRACT: AMAÇ Akut subaraknoid kanamal› (SAK) olgularda sereb- ral anevrizmalar›n saptanmas›nda spiral BT anji- yografinin (BTA) tan›sal doruluunun araflt›r›lma- s› GEREÇ VE YÖNTEM Non-travmatik SAK nedeniyle 32 olguya spiral BT anjiyografi ve DSA tetkikleri yap›ld›. BTA verileri maksimum intensite projeksiyon (MIP) yöntemi kullan›larak elde edildi. BTA ve DSA bulgular› anev- rizma varl›¤›, boyutu ve lokalizasyonu yönünden deerlendirilerek birbiriyle karfl›laflt›r›ld› BULGULAR DSA'da 32 olguda, boyutlar› 3 ile 13 mm aras›nda deiflen toplam 34 anevrizma gösterilirken 4 olgu- da anevrizma saptanmad›. BTA'da anterior komini- kan arter lokalizasyonundaki bir anevrizma göste- rilemedi. BTA dier tüm olgularda anevrizma yeri- ni, boyutunu ve oryantasyonu göstermede DSA ile korelasyon gösterdi. BTA'n›n intrakranyal anevriz- malar›n tan›s›ndaki sensitivitesi %97, spesifitesi %100 olarak bulundu. SONUÇ Spiral BTA, SAK'l› olgularda intrakranyal anevriz- malar›n tan›s›nda doruluu yüksek, ucuz ve no- ninvaziv bir görüntüleme yöntemi olup acil cerrahi gerektiren durumlarda DSA'ya alternatif güvenilir bir modalite olarak uygulanabilir . Anahtar sözcükler: ● intrakranyal anevrizma ● subaraknoid kanama ● tomografi, bilgisayarl› spiral
- [Show abstract] [Hide abstract] ABSTRACT: To investigate the diagnostic accuracy of spiral CT angiography (CTA) in detection of cerebral aneurysms in cases with acute subarachnoid hemorrhage (SAH). Spiral CT angiography and DSA examinations were performed in 32 cases due to non-traumatic SAH. CTA data were obtained by maximum intensity projection (MIP) method. CTA and DSA findings were evaluated and compared in terms of existence of aneurysm, size and location. In 32 patients, DSA detected 34 aneurysms with diameters ranging from 3 to 13 mm while four cases were free of aneurysms. With CTA, an aneurysm at anterior communicating artery location could not be demonstrated. In all other cases CTA correlated well with DSA in detecting the site, size and orientation of the aneurysms. It was found that CTA sensitivity was 97% and specificity was 100% in diagnosis of intracranial aneurysms. Spiral CTA is a highly accurate, cheap and non-invasive imaging method in diagnosis of intracranial aneurysms in cases with SAH and can be used as a safe alternative method to DSA when emergency surgery is needed.