Visualisation of intracranial aneurysms by transcranial duplex sonography

Abstract

We examined 72 patients with 89 angiographically confirmed intracranial aneurysms, using transcranial colour-coded duplex sonography (TCCD) to determine the location and size of the aneurysm. The patients were admitted for coil embolisation of their aneurysm following subarachnoid haemorrhage or because of a cranial nerve palsy. Using a 2/2.25 MHz transducer, 42 aneurysms (47%) were seen satisfactorily through the temporal bone window or foramen magnum. In 24 cases (27%) image quality was insufficient as a result of a poor bone window, of the aneurysm having a diameter of less than 6 mm or of its being in an unfavorable location. In 23 other cases (26%) it was not possible to detect the aneurysm. Thrombosed structures could be demonstrated using TCCD in 8 of 12 giant intracavernous or basilar artery aneurysms, and in 15 of 19 aneurysms treated by platinum coil embolisation. TCCD offers a noninvasive method for monitoring progressive intra-aneurysmal thrombosis following coil embolisation and for follow-up of patients with untreatable fusiform aneurysms, should this be required. Detection of small aneurysms is limited by spatial resolution and insonation angles.

Detection of intracranial aneurysms with unenhanced and echo contrast enhanced transcranial power Doppler

“…A significant relation was found between the size of the aneurysms as measured by DSA and transcranial power Doppler, in agreement with a previous study21; however, transcranial power Doppler consistently underestimated the size. The difficulty in comparing aneurysm sizes by DSA and ultrasound is compounded by the different imaging planes.…”

“…As the sensitivity in our study approaches 100% for these aneurysms, there is relevance in screening for large, unruptured aneurysms and for surveillance of such aneurysms. This study confirms the findings of previous work,21 in which the rate of aneurysm detection by transcranial power Doppler is not sufficient at present to be applied as an indiscriminate screening tool. With the use of contrast agents, transcranial power Doppler may be valuable in the detection or monitoring of large intracranial aneurysms, which attract treatment considerations.…”

“…Becker et al 14 detected 76% of aneurysms, which was higher than that detected by angiography (73%). The detection rate of Klotzsch et al 21 was, however, comparable with our study (47%) despite the prior knowledge of the presence of an aneurysm.…”

“…Using a Toshiba Powervision SSA-380 ultrasound machine with a multifrequency transcranial probe (2–3 MHz), the circle of Willis was insonated through the temporal bone window (bilaterally) in both the coronal and transverse planes21 22 and the occipital window for visualisation of the vertebral and basilar arteries 2224 Both conventional colour and power Doppler were employed; however, all aneurysms were measured in the power Doppler mode.…”

Multislice computerized tomography angiography in the evaluation of intracranial aneurysms: a comparison with intraarterial digital subtraction angiography

“…To identify patients harboring unruptured aneurysms among the numerous persons admitted to the emergency department for headaches that mimic SAH, accurate noninvasive imaging methods that allow assessment of intracranial aneurysms are of considerable interest. 38,39 Noninvasive screening methods currently under investigation include the following: CT angiography,2,11,[14][15][16]20,22,25,27,[33][34][35][36][37]3,4,6,12,17,18,23,24,26,[29][30][31]13,32 Compared with conventional IADS angiography, CT angiography is simpler and quicker to organize and perform. In the emergency setting, CT angiography can be performed immediately after a diagnosis of SAH has been given based on a routine nonenhanced CT scan of the brain.…”