Ultrasonographic criteria for diagnosing a dissection of the internal carotid artery

To evaluate the usefulness of various sonographic criteria for detecting a dissection of the internal carotid artery (ICA).

Twenty-three consecutive patients displaying typical clinical symptoms of ICA dissection were identified. The diagnosis of dissection in these cases was confirmed by MRI/MRA or arteriography. The sonographic examination was the first technical investigation and involved the combined use of Doppler and duplex sonography. The value of different sonographic criteria was evaluated for the identification of ICA dissection: 1) Morphological criteria: intramural haematoma or double lumen. 2) Haemodynamic findings of distal stenosis/occlusion in combination with suddenly appearing clinical signs of a space-occupying lesion in the respective region (Horner's syndrome, lower cranial nerve palsies). 3) Haemodynamic signs of distal stenosis/occlusion with ensuing recanalisation within a few weeks.

Morphological criteria alone allowed detection of a dissection in 47,8 % of patients. By the combined use of morphological and haemodynamic criteria ICA dissections were identified on admission in 73.9 % and after an average of 4.5 weeks (at the latest after 6 weeks) in 91.3 % of the patients.

ICA dissections can be identified sonographically with high sensitivity. In some of the cases, however, definite diagnosis can only be provided by follow-up evaluation.