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Evaluating of intracranial artery dissection using 3D-SNAP high resolution magnetic resonance:the prospective study

Min Tang¹, Jinglong Gao¹, Xin Zhang¹, Jie Gao¹, Xiaoling Zhang¹, Xiaohong Wu¹, and Zhizheng Zhuo²

¹Shaanxi Provincial People`s Hospital, xi`an, China, ²Clinical science, Philips Healthcare China, Beijin, China

Synopsis

The characteristics of intracranial artery dissection were firstly observed using three dimensional simultaneous non-contrast angiography and intra plaque hemorrhage (3D-SNAP) high-resolution magnetic resonance imaging, including intramural hematoma, double lumen and intimal flap. 43 patients were enrolled. The discovery rate of intramural hematoma, false lumen thrombosis were significantly higher in the intracranial artery dissection by 3D-SNAP than other MRI sequences. The discovery rate of double lumen and intimal flap using 3D-SNAP were minor superior to CE-T1WI sequences. The diagnosis efficiency of 3D-SNAP sequences was only lower CE-T1WI, it was the highest diagnostic efficacy in combination with 3D-SNAP and CE-T1WI sequences. Therefore, the application of 3D-SNAP would rise diagnosis rate of intracranial artery dissection, and it may become the first-line screening technology to evaluate the risk factors of stroke caused for intracranial artery dissection.

Introduction

Intracranial arterial dissection (ICAD) is a major cause for stroke in young and middle-aged people, and often causes serious complications with ischemia and hemorrhage. At present, the intraluminal imaging (DSA, CTA and MRA) cannot fully reveal the direct signs of intracranial artery dissection, their can diagnose 32%-50% in ICAD, susceptibility weighted imaging (SWI) cannot clearly observe intramural hematoma, false lumen thrombosis and duble lumen caused for magnetic sensitive artifact, slow blood flow, the all factors will reduces to the discovery rate of intracranial artery dissection [1]. However, The SNAP sequence can simultaneouly provide a full 3D luminal MRA and a naturally registered 3D intraplaque hemorrhage (IPH) visualization in a single acquisition. It can obtain good contrast among lumen, wall and IPH in plaque due to suppress blood flow signal [2]. The histopathology of intracranial arterial dissection is intramural hematoma, double lumen and intimal flap due to the intimal tear and vasa vasorum of the outer and middle membranes rupture. Therefore, the purpose of this study is to explore the pathological features of intracranial artery dissection using 3D-SNAP, to improve the diagnostic accuracy and guide clinic treatment.

Methods

We prospectively recruited patients with transient ischemic attack（TIA） or acute neurological deficit compatible with headache and dizziness from Jan 2015 to Mar 2018, patients with a history of trauma, poor image quality and clinical findings suggestive of vasculitis were excluded from study. The study was approved by local IRB. They were devided into the ICAD group (n=18) and the non-dissection group (n=25). The inclusion criteria of ICAD were as follows [3]: (a) evidence of VAD on digital subtraction angiography (DSA), (b) findings of double-lumen sign, intimal flap or intramural hematoma. The inclusion criteria of nondissection group were as follows: (a) ischemic stroke, (b) no evidence of pathognomonic ICAD imaging. All patients were performed TOF-MRA, T1WI-VISTA, T2WI, 3D-SNAP and CE-T1WI using Philips Ingenia 3.0 T MRI (ingenia, Philips Medical Systems, The Netherlands),following parameters: TR/TE:10/5ms, FOV=160*160mm2, acquisition matrix=512X512, image resolution=1*1*1mm2, acceleration factor=2, slice thickness= 0.5 mm (no gap), acquisition time approximately 3.32 minutes. Image analysis: The 3D-SNAP original data were imported into PHILIPS MR WorkSpace postprocessing workstation to generate axial view, coronal view, surface reconstruction and minimum density projection. The all patients were double-blinded analyzed image findings every sequences. The Kappa analysis was used to evaluate the consistency of the 2 physicians. The independent sample t test or chi-square test was used for clinic data, image findings between ICAD group and the non-dissection group. ROC curve was used to evaluate diagnostic efficiency of each sequence in intracranial artery dissection. P<0.05 is considered statistically significant.

Results

The age between ICAD group and the non-dissection was statistically significant (P＜0.05) (Tab.1).There was significant difference in the displaying rates of intramural hematoma, double lumen, intimal flap signs in ICAD on TOF-MRA, T2WI, T1WI-VISTA, SNAP and CE-T1WI(Tab.2,Fig.1). The SNAP was the most sensitive method for diagnosis of intramural hematoma, the CE-T1WI was the most sensitive to display double lumen and intimal flap signs(Fig.2). Areas of TOF-MRA, T2WI, T1WI-VISTA, SNAP, CE-T1WI, SNAP combined with CE-T1WI under ROC curves to diagnose ICAD were 0.663, 0.492, 0.729, 0.741, 0.752 and 0.824, respectively (Fig.3).

Discussion

3D-SNAP high-resolution magnetic resonance imaging was used for evaluation of ICAD for the first time, our results showed that the intramural hematoma, false lumen with or without thrombosis discovery rate of intracranial artery dissection were significantly higher than other imaging sequence, the discovery rate of double lumen and intimal flap using 3D-SNAP were minor superior to other sequences (P<0.05), SNAP might become a powerful tool in detecting intramural hematoma and false lumen. The single sequence diagnosis efficiency in 3D-SNAP was only lower CE-T1WI, it was the highest diagnostic efficacy in combination with 3D-SNAP and CE-T1WI sequences. The application of 3D-SNAP would significantly improve the detection rate of intracranial arterial dissection and bring benefits for ICAD patients with renal insufficiency, pregnancy and contrast allergy. It might be the most effective first line screening technology to evaluate the risk factors of stroke caused for ICAD.

Conclusion

3D-SNAP is a noninvasive and effective method which has the greatest development potential and the most promising prospects to evaluate intracranial artery dissection

Acknowledgements

The authors would like to thank Philips Healthcare for their technical assistance.

References

[1]. Han M, Rim N J, Lee J S, et al. Feasibility of high-resolution MR imaging for the diagnosis of intracranial vertebrobasilar artery dissection[J]. European Radiology, 2014, 24(12):3017-3024.

[2].Wang J, Börnert P, Zhao H, Hippe DS, Zhao X, Balu N, et al. Simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) imaging for carotid atherosclerotic disease evaluation. Magn Reson Med. 2013; 69(2):337–345

[3].Maruyama H, Nagoya H, Kato Y, et al. Spontaneous cervicocephalic arterial dissection with headache and neck pain as the only symptom. J Headache Pain 2012;13:247-53.

Figures

Tab. 1 Comparison of the clinic data between the intracranial artery dissection group and the nondissection group

Tab.2 Comparison of the IAD findings among the all sequences on HRMRI

Fig. 1 A 46 years old man with suffered from progressive neck pain, dizziness for 11 days. The absence of abnormality findings in the right vertebral on the TOF_MRA; An aneurysmal dilatation, double lumen and intimal ﬂap in the right vertebral on the T2WI, the false lumen showed inhomogeneous hypointensity（as indicated by the arrows）; An aneurysmal dilatation and double lumen in the right vertebral on the coronal T1WI, the false lumen showed inhomogeneous hyperintensity（as indicated by the arrows）; An aneurysmal dilateation, double lumen, false lumen with contrast enhancement and intimal ﬂap in the right vertebral on the CE-T1WI and PD（as indicated by the arrows）; A double lumen in the right vertebral on the 3D-SNAP, the ture/false lumen showed apparent hypo/hyper-intensity（as indicated by the arrows）.

Fig. 2 A 43 years old man presenting with dizziness and walking unstable for 6 days. The absence of abnormality findings in the basilar artery on the TOF_MRA,T2WI,T1WI-VISTA and PD; An double lumen and intimal ﬂap in the basilar artery on the CE-T1WI（as indicated by the arrows）; An intramural hematoma showed hyperintensity in the basilar artery on the 3D-SNAP（as indicated by the arrows）.

Fig.3 Comparison of diagnostic efficacy of each sequences ROC curves

Proc. Intl. Soc. Mag. Reson. Med. 27 (2019)

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