Feasibility of angiographic CT in peri-interventional diagnostic imaging: a comparative study with multidetector CT

Abstract

Background and purpose: The ability to perform neuroimaging on the angiography suite is important in making decisions during neurointerventions. Our aim was the evaluation of ACT as a fast available diagnostic tool during and after neuroendovascular procedures and the comparison of ACT with postinterventional MDCT.

Materials and methods: Eighty-four peri-interventional ACT acquisitions were obtained and evaluated: 38 after coil embolization of cerebral aneurysms, 16 after intracranial angioplasty with stent placement, and 30 after endovascular mechanical thrombectomy and lysis. Interventions and ACTs were performed on a biplane angiography system equipped with flat panel detectors. Postprocessing was performed on a dedicated workstation, and multiplanar reformations were generated. Reference studies were performed on a 16- or 128-section MDCT scanner. All studies were independently evaluated by 3 blinded neuroradiologists. The Wilcoxon test was applied for the statistical analysis.

Results: ACT and MDCT images were of equal diagnostic quality in most cases related to the supratentorial ventricular system and the detection of hemorrhages (subarachnoidal, intraparenchymal, and intraventricular). Regarding the supratentorial ventricular system, an adequate diagnostic quality was assigned to 94% of the ACT acquisitions. For the detection of hemorrhage, no statistically significant difference was noted between ACT and MDCT. However, for the infratentorial region, ACT performed relatively poorly compared with MDCT. The diagnostic evaluation of gray matter (basal ganglia, insular cortex, and central cortex) by ACT is not sufficient, with <20% of the acquisitions scoring a diagnostic value.

Conclusions: After neuroendovascular procedures and within the angiography suite, ACT enables an immediate detection of peri-interventional hemorrhage or hydrocephalus. However, for the detection of cerebral infarction, ACT is not yet reliable.

Fig 1.

A, A 51-year-old man with a symptomatic middle cerebral artery stenosis. B, After percutaneous transluminal angioplasty and application of a Wingspan stent (Boston Scientific, Natick, Massachusetts), DSA depicts the successful vessel reconstruction. C, Stent conformity and deployment are displayed on 3D reconstructions after postprocessing the same volume dataset that provided us with the ACT. The postinterventional ACT (D) shows an SAH and contrast-agent accumulation primarily in the right lateral sulcus. MDCT (E) verifies this finding. The supratentorial ventricular system can be sufficiently evaluated in both examinations. The old right anterior cerebral artery infarction can be diagnosed on MDCT (E) but is undetectable on the ACT examination (D). F, Follow-up MDCT after 3 days shows complete resolution of SAH.

Fig 2.

A 65-year-old man. A, Lateral occipital artery angiogram shows a tentorial dural fistula and a venous aneurysm. B–E, The ACT examination (B ) after EVD application and diagnostic angiography depicts a large IVH and a small IPH of the right parietal lobe. Small amounts of SAH in a frontal sulcus on the left side can also be detected on the ACT examination (D, arrow ). These findings can be confirmed on MDCT images (C and E ). The exact position of EVD catheter tip can be accurately depicted on both examinations.

Fig 3.

A, Ruptured distal carotid artery aneurysm of a 72-year-old man with acute SAH, Hunt and Hess 4. B, After endovascular treatment with Guglielmi detachable coils (Boston Scientific). C–F, ACT images (C and E) show the SAH and IVH as well as dilation of the supratentorial ventricular system. In contrast to MDCT (F), the fourth ventricle cannot be evaluated in the ACT examination (E) due to beam hardening artifacts. After implantation of a lumbar drain, follow-up MDCT scans (D and F) show a slight decrease of the lateral ventricle size.

Fig 4.

A, A 63-year-old woman with acute basilar artery thrombosis. B and C, After recanalization of the artery with a Penumbra System (Penumbra, Alameda, California) (B), an acute ischemic lesion of the right thalamus can be seen on the ACT images (C). There is no complication in the form of an IPH or SAH. Typical ring artifacts can be seen on ACT and should not be confused with areas of cerebral edema. D, The follow-up MDCT after 2 hours confirms the thalamic infarction but also depicts a right occipital lobe infarction, which was undetectable on the ACT examination.