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首页> 外文期刊>Journal of Clinical Ultrasound: JCU >Transcranial color-coded duplex sonography, magnetic resonance angiography, and computed tomography angiography: methods, applications, advantages, and limitations.
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Transcranial color-coded duplex sonography, magnetic resonance angiography, and computed tomography angiography: methods, applications, advantages, and limitations.

机译：经颅彩色编码双工超声检查，磁共振血管造影和计算机断层造影血管造影：方法，应用，优点和局限性。

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Transcranial color-coded duplex sonography (TCCD), magnetic resonance angiography (MRA), and computed tomography angiography (CTA) are novel noninvasive or minimally invasive techniques for the study of the intracranial circulation. TCCD is relatively inexpensive and permits bedside examination. It improves the accuracy and reliability of conventional transcranial Doppler studies. The main limitation of TCCD are the ultrasonic windows. They restrict the area of insonation to the major cerebral arteries and the proximal part of its branches, lower the spatial resolution, and may prevent transtemporal insonation. Using MRA, both large and small intracranial arteries and veins can be imaged by selecting the appropriate imaging parameters. MRA provides morphologic information about the cerebral vessels, relying on blood flow as the physical basis for generating contrast between stationary tissues and moving spins. MRA is highly sensitive for the detection of occlusive disease in large intracranial arteries. However, with bright blood techniques the degree of stenosis tends to be exaggerated. Flow direction, eg, in collaterals, can be determined by selective or phase-contrast MRA. Perfusion imaging techniques provide information about blood flow at the capillary level. Diffusion imaging depicts molecular motion. TCCD and MRA used in combination or alone may eliminate the need for intra-arterial digital subtraction angiography (DSA) in most patients studied for occlusive cerebrovascular disease. DSA may be reserved for those patients where there is disagreement among the noninvasive techniques, and for the diagnosis of cerebral aneurysms and arteriovenous malformations. CTA relies on spiral CT technology and intravenous contrast injection. To date, intracranial use has been predominantly for the diagnosis of aneurysms. The role of CTA for the detection of nonaneurysmal intracranial vascular disease has yet to be established.
机译：经颅彩色编码双工超声（TCCD），磁共振血管造影（MRA）和计算机断层造影血管造影（CTA）是研究颅内循环的新型无创或微创技术。 TCCD相对便宜，并且可以在床旁检查。它提高了常规经颅多普勒研究的准确性和可靠性。 TCCD的主要限制是超声波窗口。它们将共鸣区域限制在主要的脑动脉及其分支的近端，降低了空间分辨率，并可能防止跨颞声共鸣。通过使用MRA，可以通过选择适当的成像参数对大，小颅内动脉和静脉成像。 MRA依靠血流作为在固定组织和运动自旋之间产生对比的物理基础，提供有关脑血管的形态学信息。 MRA对大颅内动脉闭塞性疾病的检测高度敏感。然而，使用鲜血技术时，狭窄程度倾向于被夸大。可以通过选择性或相衬MRA确定流向，例如侧支流。灌注成像技术可提供有关毛细血管水平的血流信息。扩散成像描绘了分子运动。在大多数研究闭塞性脑血管疾病的患者中，将TCCD和MRA组合使用或单独使用可能无需进行动脉内数字减影血管造影（DSA）。 DSA可以保留给那些非侵入性技术存在分歧的患者，以及诊断脑动脉瘤和动静脉畸形的患者。 CTA依靠螺旋CT技术和静脉造影剂注射。迄今为止，颅内使用主要用于诊断动脉瘤。 CTA在检测非动脉瘤性颅内血管疾病中的作用尚未确定。

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