Identification of Internal Carotid Artery Dissection by Transoral Carotid Ultrasonography

Abstract

Background and Purpose: Conventional transsurface carotid ultrasonography (TSCU) via the cervical surface often fails to detect dissection of the extracranial internal carotid artery (ICA). The role of transoral carotid ultrasonography (TOCU) in the detection of ICA dissection was examined. Method: Patients with unilateral extracranial ICA dissection identified by digital subtraction angiography (DSA) from our database of patients with ischemic stroke or transient ischemic attack (TIA) were reviewed. Findings of dissection were compared between TSCU and TOCU. Results: Eight patients (7 men, 37–69 years old), including 7 with ischemic stroke and 1 with TIA, had ICA dissection. By DSA, dissection was identified between the first and third vertebrae in 4 patients and from the third cervical vertebra to the intracranial level in the remaining 4. TOCU images revealed an intimal flap as definite evidence of dissection in all patients. In 7 patients, color flow signals were not seen in false lumens, indicating thrombosed lumens. Four patients showed morphological changes of dissection on follow-up TOCU, including a patient with recovery of color flow signals in false lumens. The diameter of the dissected ICA was 7.3 ± 0.7 mm and that of the contralateral ICA was 4.9 ± 0.6 mm (p = 0.008). In contrast, TSCU did not enable any conclusive findings of ICA dissection to be made in any patient. Six patients had intramural hematoma on T₁-weighted MRI, and 2 had an intimal flap with a double lumen on magnetic resonance angiography. Conclusion: TOCU has advantages over TSCU in achieving an accurate diagnosis and follow-up evaluation of ICA dissection.

Utility of transoral and transcranial ultrasonography in the diagnosis of internal carotid dissection: a case report

“…With this method, ICA dissection is visualized as a refinement in color Doppler mode, with low velocities in pulsed wave Doppler, as evidenced in our case [6]. Suzuki et al [7] published a series of cases demonstrating the usefulness of transoral US in the diagnosis of ICA dissection, which is comparable to that of digital subtraction angiography and MRA. Benninger et al [8] reported the usefulness of the combination of the assessment or neck and intracerebral vessels using US in the diagnosis of this entity, based mainly on identifying altered arterial flow patterns.…”

Sudden-onset anisocoria in a patient with upper respiratory tract infection

“…3,4 Transoral carotid ultrasonography (e) is a relatively novel diagnostic tool that has been used to investigate distal flow in the extracranial internal carotid artery. 5 In our patient, an urgent CT angiogram showed eccentric luminal narrowing of the distal cervical and petrous segments of the right carotid artery at the skull base, consistent with carotid artery dissection ( Figure 1A). Because the dissection extended intracranially, involving the petrous portion, we started antiplatelet therapy with acetylsalicylic acid (ASA) 81 mg/d.…”

Contrast‐enhanced transoral carotid ultrasonography for the diagnosis and follow‐up of extracranial internal carotid artery dissection: A case report

“…Ultrasound contrast agents can be used repeatedly without nephrotoxicity. Conventional TOCU is well suited to observing lesions located in the upper extracranial ICA, making it a useful modality in the diagnosis and follow‐up evaluation of extracranial ICA dissections and aneurysms . However, color Doppler TOCU imaging may not be always able to clearly delineate the vessel lumen from the intramural hematoma because of color blurs.…”