An important clue in the sonographic diagnosis of internal carotid artery agenesis: ipsilateral common carotid artery hypoplasia

The ambiguous "internal carotid artery"-Ultrasound diagnosis of congenital absence of the internal carotid artery: A case report and review of the literature

RATIONALE

Congenital anatomical variation of internal carotid artery (ICA) rarely occurs, and congenital absence of the ICA is even rarer. Few reports are available on the diagnosis of congenital absence of the ICA by carotid doppler ultrasound (CDUS), and most cases have been identified by computed tomographic angiography (CTA) or digital subtraction angiography (DSA).

PATIENT CONCERNS

A 61-year-old male was admitted to our hospital due to dizziness for more than half a month. He was hypertensive and had been drinking and smoking for many years.

DIAGNOSES

The patient was diagnosed by carotid doppler ultrasound with congenital absence of the right ICA, confirmed by CTA and DSA. A nodular aneurysm in the anterior communicating artery was observed by CTA and DSA.

INTERVENTIONS

After relevant preoperative examinations were performed, the patient underwent right craniotomy and clipping of the aneurysm under general anesthesia 8 days after admission.

OUTCOMES

The patient recovered well after surgery and no relapses has been observed.

LESSONS

Congenital absence of the ICA is rare and usually diagnosed by CTA or DSA in clinical practice. If radiologists do not have adequate knowledge about the associated ultrasonic characteristics, a missed diagnosis may occur. As a noninvasive and rapid screening tool for cervical vascular diseases, carotid doppler ultrasound offers a new approach for the diagnosis of congenital absence of the ICA.

Unilateral developmental absence of internal carotid artery with contralateral middle cerebral artery occlusion

PURPOSE

Developmental absence of the internal carotid artery (ICA) is a rare congenital anomaly that results from an insult to the third aortic arch or dorsal aorta during early embryogenesis. Patients are often asymptomatic and are diagnosed incidentally during imaging to investigate neurological complaints.

METHODS

We report a rare finding of an absent ICA during a workup of stroke in a middle-aged patient.

RESULTS

CT brain perfusion (CTP) and CT angiography (CTA) revealed the right middle cerebral artery (MCA) thrombotic stroke with the demonstration of contralateral left ICA absence. The patient showed spontaneous recovery, and no thrombolysis or neurointervention was considered.

CONCLUSIONS

This article highlights the importance of screening the head CT on bone window settings in case of the non-visualization of ICA to differentiate congenital absence from a steno-occlusive disease. It also illustrates the role of Magnetic resonance imaging (MRI) and MR Angiography (MRA) in demonstrating further possible vascular anomalies, structural brain malformations, and collateral circulation.

Internal carotid artery agenesis disclosed by carotid ultrasonography

(Upper panels) Ultrasonography showed caliber difference of common carotid arteries (right side: 0.39 cm; left side: 0.70 cm) for right internal carotid artery agenesis. (Lower panels) Bilateral ophthalmic arteries showed anterograde flow with 50% flow reduction over right side (right: peak systolic velocity, PSV [23.3 cm/s]; end diastolic velocity, EDV [7.0 cm/s]; left: PSV [47.0/s] EDV [14.2 cm/s]).

Imaging Challenges in the Diagnosis of Anatomical Variations of the Supra-Aortic Vessels: A Case Report and Review of Literature

A 73-year-old woman was referred to our Cardiology Department due to recurrent headaches and dizziness. She had a history of hypertension of 10 years. In the territorial hospital, left internal carotid artery significant stenosis was suspected. Neurological examination and laboratory tests were normal. A neck vascular ultrasound was performed, showing a low bifurcation of the left common carotid artery (CCA) and a hypoplastic left internal carotid artery (ICA) with a sinuous path at the cervical level. Therefore, a computed tomographic (CT) angiography examination of the head and neck vessels was performed. The images confirmed the presence of a hypoplastic left ICA, anatomic variation in the left CCA, and also showed that the left vertebral artery (VA) was stemming directly from the aortic arch, exhibiting a kinking trajectory.

Neuroradiological findings in Alagille syndrome

Alagille syndrome (ALGS) is a multisystemic disease caused by mutations in genes of Notch pathway, which regulates embryonic cell differentiation and angiogenesis. Clinically, ALGS is characterized by cholestasis, cardiac defects, characteristic facial features, skeletal and ophthalmologic abnormalities. The aim of this review is to illustrate neuroradiological findings in ALGS, which are less well-known and prevalent, including cerebrovascular anomalies (such as aneurysms, dolichoectasia, Moyamoya syndrome and venous peculiarities), Chiari 1 malformation, craniosynostosis, intracranial hypertension, and vertebral anomalies (namely butterfly vertebra, hemivertebra, and craniocervical junction anomalies). Rarer cerebral midline malformations and temporal bone anomalies have also been described.

Congenital absence of the internal carotid artery with intercavernous anastomosis

Congenitally absent internal carotid artery with intercavernous anastomosis is an exceedingly rare vascular anomaly. We report such a case in a 65-year-old man with chronic symptoms resembling sporadic transient ischemic attacks. While these patients are usually asymptomatic due to compensatory collateralization, they are at increased risk of aneurysm formation, and thus proper identification is important. This report serves as both a case of a very rare anomaly and as a lesson on how to avoid this misdiagnosis by carotid duplex sonography. Additionally, we review the limited number of published cases of congenitally absent internal carotid artery with intercavernous anastomosis.

Agenesis of the internal carotid artery

Agenesis of the internal carotid artery is a rare anomaly. It is usually asymptomatic because of the presence of anastomoses, but it can be associated with complications, especially when there is evidence of other anatomical abnormalities or severe atherosclerotic disease. We report the case of a 63-year-old female patient with hypertension and diabetes and a history of intracranial aneurysm clipping. Doppler ultrasonography and computed tomography angiography of the carotid and vertebral arteries showed unilateral agenesis of the left internal carotid artery. This report aims to highlight the importance of suspecting vascular malformations during investigation of neurological conditions. Internal carotid agenesis has a significant association with intracranial aneurysms and their early detection can spare the patient serious complications.