Spiral CT angiography and surgical correlations in the evaluation of intracranial aneurysms

Abstract

We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 +/- 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3-0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 +/- 0.12 cm vs 1.09 +/- 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients.

Detection of Aneurysms by 64-Section Multidetector CT Angiography in Patients Acutely Suspected of Having an Intracranial Aneurysm and Comparison with Digital Subtraction and 3D Rotational Angiography

“…The sensitivities in initial studies of SSCTA varied widely, ranging from 67% to 100%, with significant difficulty noted in detecting aneurysms less than 4 mm. [17][18][19][20][21][22] When 4MSCTA emerged, results among several studies were also variable but largely demonstrated that the sensitivity was more than 90% in aneurysms at or more than 4 mm, whereas the results for aneurysms less than 4 mm in size were controversial; in particular, the NPVs were reported as far under 90% on a per-aneurysm basis of evaluation, suggesting that smaller aneurysms less than 4 mm could be missed by 4MSCTA. [9][10][11] Similar but slightly improved results have been reported with 16MSCTA, with further improved NPVs and sensitivity, though there still remains some difficulty in aneurysms less than 3-4 mm.…”

Diagnostic Value Of 64-slice Cta In Detection Of Intracranial Aneurysm In Patients With Sah And Comparison Of The Cta Results With 2d-dsa And Intraoparetaive Findings

“…Single slice CTA studies reported sensitivities varying from 67% to 100% (9)(10)(11)(12)(13)(14). With the introduction of multi-slice technology, spatial and temporal resolution of CT has increased dramatically, and this increased the diagnostic value of CTA in detecting intracranial aneurysms.…”

Prevalence of Intracranial Aneurysms Found on Computed Tomography Angiogram in Patients Presented with Traumatic Subarachnoid Haemorrhage

“…After 7 days, plain CT is positive in only 50% of cases in SAH. Literature had been reporting that CTA processed a sensitivity ranges between 67% to 100% and specificity between 50% to 100% in diagnosing intracranial haemorrhage [24][25][26]. However, lumbar puncture should be performed in any patient with suspected SAH and negative or equivocal results on plain CT head [27].…”