Noninvasive depiction of the lenticulostriate arteries with time-of-flight MR angiography at 7.0 T

Abstract

Objective: The lenticulostriate arteries (LSAs) are small penetrating branches which are feeding the basal ganglia. Thus far, no noninvasive imaging method has been capable of visualizing the LSAs. We explore the possibilities of three-dimensional time-of-flight (TOF) MR angiography (MRA) at 7 T to visualize the LSAs.

Subjects and methods: We included 10 healthy volunteers (age range, 19-46 years; 4 men, 6 women). TOF MRA was performed on a 7.0-tesla ultra-high-field MR system equipped with a volume transmit and 16-channel receive head coil. Images were acquired with a 0.6-mm isotropic resolution with a scan time of 9 min and 33 s. The mean length and number of LSAs (with standard deviations) were evaluated on coronal and sagittal maximum intensity projections of the axial source data set.

Results: The mean total number of LSAs (+/- standard deviation) visualized on the left and right side combined was 7.0 +/- 1.8. Per side, the average number of visualized LSAs was 3.5 +/- 1.1, and the maximum number of visualized LSAs was 5. The mean length of the visualized LSAs was 23 +/- 6.6 mm. The most laterally visualized LSAs showed the longest length (29 +/- 5.0 mm), with a stepwise decrease in length for the more medially visualized LSAs.

Conclusion: We show the ability of TOF MRA at 7.0 T to image the LSAs. Direct imaging of these LSAs in clinical studies may increase the understanding of the pathophysiology of brain tissue changes, such as lacunar infarcts, which are thought to be caused by small-vessel disease.