High temporal and spatial resolution 3D time‐resolved contrast‐enhanced magnetic resonance angiography of the hands and feet

Abstract

Methods are described for generating 3D time-resolved contrast-enhanced MR angiograms of the hands and feet. Given targeted spatial resolution and frame times, it is shown that acceleration of about one order of magnitude or more is necessary. This is obtained by a combination of 2D Sensitivity Encoding (SENSE) and homodyne (HD) acceleration methods. Image update times from 3.4 to 6.8 sec are provided in conjunction with view sharing. Modular receiver coil arrays are described which can be designed to the targeted vascular region. Images representative of the technique are generated in the vasculature of the hands and feet in volunteers and in patient studies.

Non-Contrast-Enhanced MR Angiography (NCE-MRA) of the Hand Using Flow-Sensitive Dephasing (FSD)-Prepared Steady-State Free Precession (SSFP) in Patients with Rheumatoid Arthritis

“…Previous works have demonstrated that FSD preparation with suitable motion-sensitized gradients can suppress complex blood flow in the hand or foot arteries [11,12]. In this study, 96 % of vascular segments detected by FSD-NCE-MRA could be used for clinical diagnosis, which is significantly higher than dynamic CE-MRA (Table 1) and conventional enhancement angiography reported in previous investigations [15]. This superior imaging quality is resulted from the larger SNR and higher spatial resolution.…”

“…This superior imaging quality is resulted from the larger SNR and higher spatial resolution. The spatial resolution of FSD-NCE-MRA in this study was adjusted to 0.9 mm in each direction, which is significantly higher than that achieved using CE-MRA for detecting the peripheral arteries [15] and almost equivalent to the high-resolution CE-MRA of hand arteries [16]. Considering the typical circuitous paths and small luminal diameters (1-2 mm) of hand arteries, obtaining homogeneous submillimeter spatial resolution in each direction could enhance diagnostic accuracy in patients with the hand arterial lesions.…”

Acute Arterial Thrombosis of the Hand

“…15 Obtaining high-quality images can require considerable time and is complicated by scatter from adjacent ACUTE ARTERIAL THROMBOSIS OF THE HAND veins and the complex timing required for contrastenhanced image acquisition. Using time-resolution, contrast-enhanced magnetic resonance imaging, and extremity-specific coils, Haider et al 16 obtained magnetic resonance images depicting radial and ulnar digital vessels. However, the techniques used to visualize arteries at the digital level are not yet widespread and MRA remains limited by the inability to perform concomitant interventional procedures.…”

Unenhanced MR Angiography of the Foot: Initial Experience of Using Flow-Sensitive Dephasing–prepared Steady-State Free Precession in Patients with Diabetes

“…However, with conventional bolus-chase multi-station technique, it is a challenge for CE-MRA to depict pedal arteries without venous contamination due to the short contrast first-pass window in the arteries [10]. Recently, time-resolved CE-MRA technique has been developed to prevent venous contamination in the foot [11], but multiple injections of contrast agent are required if more regions of the lower extremities are needed to scan [12–15]. In addition, due to the potential risk of nephrogenic systemic fibrosis, the use of gadolinium-based MR contrast agent should be avoided in patients with severe renal insufficiency [16], which is more prevalent in diabetic patients [17, 18].…”