Pozzi Mucelli R, Shariat Razavi I, Tarjan Z, Pozzi Mucelli F, Magnaldi S
Istituto di Radiologia, Università di Trieste.
Radiol Med. 1995 Mar;89(3):237-44.
Three-dimensional Computed Tomographic Angiography (3D CTA) is a new imaging technique for vascular structures. This study was aimed at investigating the diagnostic role of 3D CTA in the intracranial and extracranial arteries. Fifteen patients with intracranial artery disease (thirteen with aneurysms and two with arteriovenous malformations) and fifteen patients with stenosis of the common, internal or external carotid arteries underwent 3D CTA. All patients had been examined with intraarterial angiography. The CT examinations were performed with dynamic scanning during intravenous contrast agent administration. Three-millimeter thick contiguous slices were obtained in the cervical region and 1.5-mm contiguous slices in the intracranial region. CT findings were processed to produce 3D views on an independent workstation. 3D CTA results were compared with those of intraarterial DSA in all cases. Agreement was found in 13 of 15 cases of intracranial vascular abnormalities, and in 26 of the 30 carotid arteries in classifying the severity of the stenosis. The 3D views, which exhibit an excellent image quality, seem to be comparable to angiography in the intracranial and extracranial arteries. The main advantages of this technique are: 1) its low invasivity since only an intravenous contrast agent injection is required; 2) its easy and fast acquisition (2-3 minutes are needed if a non-spiral CT unit is used and less than one minute with spiral CT); 3) good demonstration of the calcified plaques which can be also removed with the softwares available at the workstation, to show the overall vessel lumen; 4) thanks to its simplicity the examination can also be performed in emergency (i.e. in patients with subarachnoid hemorrhage, if plain CT is positive for subarachnoid bleeding). Its main limitations are: 1) the need of an adequate concentration of contrast agent in the vessels; 2) artifacts due to calcified and bone structures; 3) no information about vessel inflow; 4) limited discrimination between arteries and veins in some areas (cavernous sinus); 5) limited field of view compared to angiography.
三维计算机断层血管造影（3D CTA）是一种用于血管结构的新型成像技术。本研究旨在探讨3D CTA在颅内和颅外动脉中的诊断作用。15例颅内动脉疾病患者（13例患有动脉瘤，2例患有动静脉畸形）和15例颈总动脉、颈内动脉或颈外动脉狭窄患者接受了3D CTA检查。所有患者均接受了动脉内血管造影检查。CT检查在静脉注射造影剂期间进行动态扫描。在颈部区域获得3毫米厚的连续切片，在颅内区域获得1.5毫米厚的连续切片。对CT结果进行处理，以便在独立的工作站上生成三维视图。在所有病例中，将3D CTA结果与动脉内数字减影血管造影（DSA）结果进行比较。在15例颅内血管异常病例中的13例以及在30条颈动脉中的26条中，在狭窄严重程度分类方面发现了一致性。三维视图具有出色的图像质量，在颅内和颅外动脉方面似乎与血管造影相当。该技术的主要优点是：1）侵入性低，因为仅需静脉注射造影剂；2）采集简便快速（如果使用非螺旋CT设备需要2 - 3分钟，使用螺旋CT则不到1分钟）；3）能很好地显示钙化斑块，还可使用工作站上的软件去除钙化斑块，以显示血管腔全貌；4）由于其操作简单，该检查也可在紧急情况下进行（例如蛛网膜下腔出血患者，如果平扫CT显示蛛网膜下腔出血阳性）。其主要局限性是：1）血管内需要足够浓度的造影剂；2）钙化和骨骼结构导致的伪影；3）无关于血管流入的信息；4）在某些区域（海绵窦）动脉和静脉之间的鉴别有限；5）与血管造影相比视野有限。
