Imaging investigation of cervicocranial artery dissection by using high resolution magnetic resonance VWI and MRA: qualitative and quantitative analysis at different stages

Abstract

Background: To explore the value of magnetic resonance angiography (MRA) and high resolution magnetic resonance vessel wall imaging (HRMR-VWI) in cervicocranial artery dissection (CCAD) for the disease diagnosis, course staging and treatment. On the basis of qualitative evaluation, this study also extract the changes of different stages in vessel wall in different vessel segments to identify imaging indicators for the quantitative evaluation of CCAD.

Methods: We retrospectively enrolled 34 patients with CCAD (38branches) with conventional MRA and HRMR-VWI examinations. Two radiologists independently analyzed imaging features of vessel wall and lumen in the different stages, and the typical sign detection of artery dissection were compared between MRA and HRMR-VWI. Then the parameters of vessel wall was quantitatively evaluated by the post-processing software (Vesselmass, Leiden University Medical Center, Leiden, The Netherlands.

Results: HRMR-VWI revealed typical sign detection of artery dissection in all patients in the acute and subacute stage. Among them, the intimal flap/double lumen sign ditection were more common than the MRA, there was significant difference (P = 0.012). MRA revealed typical sign detection of artery dissection in more than half the patients, and the detection was no significant difference at the chronic stage between MRA and HRMR-VWI (P = 1.000/1.000/0.761). In the acute and subacute stage, the typical sign detection of intramural hematoma and Grade II enhancement revealed by HR-MRI was higher than the observations in the chronic stage (P = 0.000/0.000/0.016), while there was no significant difference by MRA (P = 0.902). The values of wall thickness, relative signal intensity of vessel wall enhancement, relative signal intensity of intramural hematoma (IMH), and percentage of stenosis in CCAD decreased from acute to subacute and then to chronic stages. Each quantitative parameter in patients with CCAD in the early stages (i.e., acute and subacute stages) was significantly different from that in patients with CCAD in the recovered group at chronic stage (P < 0.05). Wall thickness and relative signal intensity of vessel wall enhancement in patients with CCAD in the early stages were not significantly different from those in patients with CCAD in the incompletely recovered group at chronic stage (P > 0.05).

Conclusions: As the only noninvasive imaging technology, HRMR-VWI displays the structure of the vessel wall in vivo, showing not only excellent performance in the early diagnosis of CCAD, but also describing the changes of different stages in the qualitative and quantitative characteristics of vessel wall. It also helps to guide the diseasediagnosis, course staging and treatment of CCAD. Although the diagnostic efficacy of MRA was not as good as HRMR-VWI, it should be the first choice of method for routine examination in evaluating CCAD, especially at the chronic stage of CCAD.

Keywords: Cervicocranial artery dissection; Different stages; High resolution magnetic resonance vessel wall imagin; Magnetic resonance angiography.

Fig. 1

Outlines of the external and internal lumen contours in the 2D cross-sectional images using the vessel mass software. The entire vessel wall area was automatically divided into ten evenly spaced segments by two contours. a-d The normal vessel wall contour; e-h the intramural hematoma (IMH) contour; and i-l the double-lumen contour

Fig. 2

Images of a 48-year-old male patient who presented with transient loss of consciousness and acute headache for 6 h. a Computed tomography angiography (CTA) showed that the M1 segment was slightly swollen at the end, which was not obvious (see arrow). This patient was diagnosed as normal at the time of admission. b Computed tomography (CT) showing the subarachnoid hemorrhage of the patient; c-d 1 month later, diffusion-weighted imaging (DWI) and susceptibility weighted imaging (SWI) showing saccular aneurysm; e magnetic resonance angiography (MRA) showing an aneurysm at the M1 segment (see arrow); and f-h high-resolution magnetic resonance imaging (HRMR-VWI) showing aneurysmal protrusion with thickened residual wall at the end of the M1 segment and a crescent-shaped hematoma under the tunica adventitia (see arrow)

Fig. 3

Images of a 27-year-old female patient who presented with a headache and dizziness for 8 h. f Acute infraction/ischemia in the left cerebellar hemisphere. a-b, c MRA revealed V2–V4 tapered stenosis (red arrows), and regularity and local aneurysmal dilatation of the V3 segment vessel wall of the left vertebral artery. d HRMR-VWI showing extensive IMH (red arrow) of the right V2–V4 segments, compressing and narrowing the true lumen; and e intimal-flap-tearing (yellow arrows) in the left V3 segment and an IMH in the left V3–V4 segments, compressing and narrowing the true lumen

Fig. 4

Images of a 65-year-old male patient who presented with repeated dizziness for more than 11 years and recurrence for more than 1 month. a, d, g MRA showing irregularity and aneurysmal dilatation of the vessel wall of the C1 segment of the right internal carotid artery. The wall of the C1 segment of the left internal carotid artery was not smooth, but no obvious abnormality was observed. b-c Imaging features of the double lumen and confined thickening of the vessel wall, showing Level 1 vessel wall enhancement; e-f the posterior wall of the lumen was thickened with confined thickening and Level 0 enhancement

Fig. 5

Images of a 56-year-old female patient who presented with repeated headache for more than 10 years and recurrence for 1 month. a, d, g MRA showing irregularity of the vessel wall and aneurysmal dilatation and protrusion of the C1 segment of the right internal carotid artery. The vessel wall of the C1 segment of the right internal carotid artery also had irregularity and aneurysmal dilatation. b-c, e-f HRMR-VWI showing imaging features of the double lumen and limited thickening of the vessel wall, as well as Level 1 vessel wall enhancement (red arrows), pseudoaneurysm formation with limited thickening of the vessel wall and Level 2 vessel wall enhancement (green arrows), and intimal-flap-tearing of the C1 segment of the left internal carotid artery (yellow arrows)

Fig. 6

HR-MRI images of two patients. a-d HRMR-VWI taken at admission of a 55-year-old male patient who presented with repeated headache for 3 years. A thrombotic aneurysm of the V4 segment of the right vertebral artery, compressing the brain stem (mass effect) was observed. e-i HR-MRI taken during physical examination of a 43-year-old female patient with a history of hypertension showed a thrombotic aneurysm of the V4 segment of the right vertebral artery, and the compressed vessel was slightly narrowed

Fig. 7

Quantitative parameters of vessel walls of CCAD at different stages

Fig. 8

Quantitative parameters of vessel walls of CCAD at different stages