Atherosclerosis is a major cause of ischemic stroke [1-2]. The high resolution magnetic resonance imaging (MRI) of vessel wall can detect nonstenotic atherosclerotic plaque missed by luminal angiography. This work aims to develop a multi-channel radiofrequency (RF) coil system with high spatial resolution capability and large longitudinal coverage for the intracranial and extracranial artery wall imaging in one setting.A “24+8” channel coil system for simultaneous imaging of extracranial and intracranial arterial wall is developed by combining the designed 24-channel head coil [3] with a separate 8-channel carotid coil as shown in Fig. 1. The “24+8” channel coil system is compared with the “12+4+8” configuration [4] (12-channel head coil combing with 4-channel neck coil and 8-channel carotid coil) for their SNR distribution. Phantom study: A cylindrical phantom (filled with 1.24g/L NiSO4•6H2O and 2.62g/L NaCl, from Siemens) measuring 160mm in diameter and 320mm in length is used to evaluate the coil system's sensitivity over an area of interest large enough to cover the head and neck. A gradient echo (GRE) sequence with the following parameters is used for image acquisitions: TR = 300ms, TE = 10ms, bandwidth = 130Hz/pixel, FOV = 320×320mm², slice thickness = 3mm, acquisition matrix = 256×256, flip angle = 60 degree. Sagittal and coronal images are acquired. Noise images are acquired by setting transmit voltage to zero on the scanner. The covariance root sum of squares (Cov-SoS) [5] method was used to reconstruct the images. The SNR map was calculated based on reference [5]. In-vivo study: A patient previously diagnosed to have both intracranial and extracranial atherosclerosis is recruited and scanned with the proposed “24+8” channel coil system to validate its ability to image vessel walls. A T1w-SPACE sequence, modified to support DANTE with improved CSF signal suppression, is used. The 3D imaging volume covers the area from the extracranial to intracranial arteries. Imaging parameters are: FOV = 159×212mm², ETL = 35, ESP = 4.34ms, resolution matrix = 256×336, TR/TE = 1140/27ms, bandwidth = 531Hz/ pixel, averages = 1.4 (21), iPAT = 2, partition = 72, total time = 7m36s. Figure 2 (A1-A4) shows how the SNR varies with the imaging volume in the proposed “24+8” channel coil system and the “12+4+8” configuration. Their SNR variation over the 320mm region is also shown in Fig. 2 (A5-A6). In the head region, the SNR of the proposed “24+8” channel coil system is significantly higher than that of the “12+4+8” configuration. In the carotid region, the SNR of the proposed “24+8” channel coil system is almost identical to that of the “12+4+8” configuration. The curve reconstruction results of pre-contrast left and right intracranial and extracranial arterial vessel wall for the patient obtained with the proposed coil system are shown in Fig. 3(a) with isotropic spatial resolution of 0.6mm3. The plaques at M1 segment of the mid cerebral artery and carotid bifurcations are demonstrated in Fig. 3(b) and (c). The vessel wall of intracranial and extracranial artery and surrounding tissues visualization can be clearly depicted in this case. This manifests that the proposed “24+8” channel coil system is capable of intracranial and extracranial arterial vessel wall imaging in human examinations.In this study, a “24+8” channel coil system is developed by combining a 24-channel head coil with dedicated 8-channel carotid coil for MR imaging of intracranial and extracranial arteries wall. Compared to the “12+4+8” configuration, the proposed “24+8” channel coil system is superior in terms of SNR in head part and nearly the same in neck part. The high resolution images with 0.6 mm³ are obtained with the proposed “24+8” channel coil system from a patient in vivo. For the “24+8” channel coil system, the SNR is not sufficient in upper torso. Some optimizations of the “24+8” channel coil system are needed in the future study to image the arterial vessel wall in upper torso.