Background and Aims

Ultrahigh-field strength 7 Tesla (7T) MRI provides a high signal to noise ratio which allows higher spatial resolution imaging and consequently its availability, for the first time allows visualisation of the very small perforating (Lenticulostriate, LSA) arteries non-invasively in humans. Using Time-of-Flight MR angiography technique, 7T MRI can be used to obtain angiographic imaging of these small cerebral vessels. The aim of this study was to visualize LSA arising from the Middle Cerebral and Anterior Cerebral arteries using ToF MRA at 7T.

Methods

Pilot study of 5 healthy subjects (mean age 39.4±19.2 years) with no history of neurological disease or vascular pathology who underwent 3D ToF MRA technique on a whole-body human 7T MR system equipped with a 32-channel receive coil. Set protocols were modified in between subject scans to achieve the best possible resolution, with scan time of 10 minutes. LSAs were identified on axial and coronal maximum intensity projections of 15mm thickness.

Results

The images showed good contrast between the LSAs and the background. On average, 5.0±1.2 stems and 7.2±1.5 branches of LSAs were visualized on both left and right sides. Across all LSAs identified, mean length was 22.6±9.9 mm. 3D volume rendered images of the ToF MRA (image) was used to ensure landmarks and confirm LSA origin.

Conclusions

This pilot study shows our ability to visualise LSAs using 7T ToF MRA. This technique can be exploited in understanding the underlying arterial pathology in patients with lacunar infarcts caused by cerebral small vessel disease stroke.

Clinical Trail Registration: https://clinicaltrials.gov/ct2/show/NCT04330222