Purpose: Comparison of different MR-examination techniques for the diagnosis of acute spontaneous internal carotid artery dissection.
Patients and methods: 13 patients (age range 23-59 years) with symptomatic spontaneous dissection of the internal carotid artery were examined. The MRI protocol contained a transverse spin echo sequence, a time-of-flight MR-angiography and a coronal fat suppressed T1-weighted sequence. The earliest examination was performed three days after symptom onset. Follow-up extended up to 30 months. We compared the three different sequences to find out the one that demonstrated the hematoma best.
Results: MR-angiography shows a narrowing of the vessel diameter in early examinations. During the subacute stage methemoglobin can obscure this finding. From the third day on fat suppressed T1-weighted images showed a hyperintense hematoma that strongly contrasted to the surrounding fatty tissue. Fat suppressed images showed a hyperintense hematoma up to 10 months after symptom onset while MRA and spin echo sequences did not.
Conclusions: Fat suppressed T1-weighted images are superior in showing vessel wall hematoma and should thus be used in the standard MR-protocol for spontaneous internal carotid artery dissection.