Changes of size and shape of small, unruptured intracranial aneurysms in repeated computed tomography angiography studies.

Abstract

IntroductionUnruptured intracranial aneurysms (UIAs) are frequently detected in noninvasive imaging studies such as computed tomography angiography (CTA) or magnetic resonance angiography (MRA). If small, UIAs are observed in these modalities in order to detect growth or shape change, but there are many questions about proper protocol of the follow-up.AimTo assess changes of small (< 7 mm) UIAs dome size and shape in repeated CTA studies as predictors of growth and rupture.Material and methodsOne hundred and ten UIAs (10 posterior circulation) in 70 patients (55 women) were observed, with a cumulative observation time of 333.32 years. Aneurysms’ dome and neck perpendicular dimensions were measured in the first and the last CTA study at least twice with the developed application. Confidence intervals (CI) for measurements and dome shape parameters were calculated. For aneurysms ruptured during follow-up intermediate studies were analyzed. Patients’ clinical information was recorded. The aneurysm growth detection algorithm integrated CI and spatial resolution of the CT scanner.ResultsTwenty-three aneurysms increased in volume, 10 in height and 14 in dome width. Volume increased in 90% of cases of height and 93% of width increase. Posterior circulation aneurysms grew faster than anterior ones (p < 0.003), but calculated time to significant size increase (eT) did not differ between the groups due to higher CI in the posterior circulation. Analysis of eT with Kaplan-Meier curves showed that 75% of growing aneurysms could be detected in the first 3 years of observation. During the follow-up 3 aneurysms bled, and they grew faster than other growing aneurysms. Two of the bleeding aneurysms formed daughter sacs.ConclusionsDome volume assessment is superior to single dimension assessment in aneurysm growth detection. Confidence intervals assessment helps to avoid overestimation of growth. Seventy-five percent of growing aneurysms could be detected in the first 3 years of observation. Daughter sac formation and fast increase in size are strong predictors of aneurysm rupture.

Control study of low tube voltage computed tomography angiography (CTA) and digital subtraction angiography (DSA) in diagnosing intracranial micro‐aneurysm

“…IMA is not uncommon, accounting for approximately 25% of the total number of patients with IC rupture; however, it can cause severe SAH. CTA has been clinically used as a routine means of diagnosing IA owing to its high speed and effective diagnosis ; ‐ ; however, it is also controversial because of its radiation problems, as well as the detection rate of IMA . It is therefore necessary to further discuss the feasibility of L‐CTA in displaying IMA.…”

“…CTA has been clinically used as a routine means of diagnosing IA owing to its high speed and effective diagnosis 3; 10-12 ; however, it is also controversial because of its radiation problems, as well as the detection rate of IMA. [9][10][11][12]15 It is therefore necessary to further discuss the feasibility of L-CTA in displaying IMA. Currently, there has been no control study comparing L-CTA and 3DRA in displaying IMA.…”

“…Approximately 80–90% of spontaneous subarachnoid hemorrhage (SAH) is caused by the rupture of IA, and the mortality of untreated aneurysmal SAH in the first month is as high as 43–67%; therefore, early diagnosis and treatment is essential. Although magnetic resonance angiography (MRA) is a radiation‐free alternative for the diagnosis of IA, and MRA imaging has been developed in recent years, its results may be affected owing to long acquisition times, flow empty phenomena, and SAH patients' disturbance‐induced movement artifacts. Computed tomography angiography (CTA) plays an increasingly important role in screen suspected IA patients, and has been widely used as a routine diagnostic tool for IA .…”

“…Computed tomography angiography (CTA) plays an increasingly important role in screen suspected IA patients, and has been widely used as a routine diagnostic tool for IA . However, the accuracies of CTA in diagnosing intracranial micro‐aneurysms (IMA) vary from 61% to 98.2%; moreover, the detection rate of IMA when CTA is utilized is controversial, yet the detection rate of IMA is an important indicator for judging CTA's sensitivity. In addition, the radiation dose of CT scanning is also a matter of concern .…”

Treatment of Unruptured Cerebral Aneurysms with the Mineralocorticoid Receptor Blocker Eplerenone—Pilot Study

“…The overall annual rupture rate (median size, 4 mm). 10,[13][14][15] In our eplerenone-treated patients (mean aneurysmal size, 4.6 mm) it was .65%, and no aneurysms smaller than 9 mm ruptured. In UCAS Japan 10 the annual rupture rate for aneurysms measuring 3-4, 5-6, and 7-9 mm were .36%, .50%, and 1.69%, respectively.…”