A noncontrast-enhanced pulse sequence optimized to visualize human peripheral vessels

Abstract

The purpose of this paper is to present a pulse sequence optimized to visualize human peripheral vessels. The optimized MR technique is a 3D multi-shot balanced non-SSFP gradient echo pulse sequence with fat suppression. Several imaging parameters were adjusted to find the best compromise between the contrast of vascular structures and muscle, fat, and bone. Most of the optimization was performed in the knee and calf regions using multi-channel SENSE coils. To verify potential clinical use, images of both healthy volunteers and volunteers with varicose veins were produced. The balanced non-SSFP sequence can produce high-spatial-resolution images of the human peripheral vessels without the need for an intravenous contrast agent. Both arteries and veins are displayed along with other body fluids. Due to the high spatial resolution of the axial plane source or reconstructed images, the need for procedures to separate arteries from veins is limited. We demonstrate that high signals from synovial joint fluid and cystic structures can be suppressed by applying an inversion prepulse but at the expense of reduced image signal-to-noise and overall image quality.

Visualization of deep veins and detection of deep vein thrombosis (DVT) with balanced turbo field echo (b‐TFE) and contrast‐enhanced T1 fast field echo (CE‐FFE) using a blood pool agent (BPA)

“…One unsolved aspect is whether the use of contrast-enhanced MRI adds significant diagnostic value, or just costs, potential complications, and discomfort for the patient. This study investigated image quality and the ability to visualize the deep veins and DVT of the lower limb using two novel MRI venography techniques: b-TFE with fat suppression optimized for imaging of peripheral vessels (8) and CE-FFE with BPA. The two sequences acquire axial raw data and allow multiple plane reconstructions and 3D multi-intensity projections.…”

“…Four patients had DVT of the right limb, and mean symptom duration was 8.3 days (range, [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Figure 3 shows examples of patients with DVT and direct and indirect findings of venous thrombosis in calf, knee, and thigh in corresponding images of the two MRI techniques.…”

“…Recently, a three-dimensional (3D) multishot balanced turbo field echo (b-TFE), a.k.a. non-steadystate free-precession (transient SSFP), gradient-echo pulse sequence with fat suppression has been developed and optimized for the visualization of peripheral vessels (8). The b-TFE technique has several favorable characteristics including high signal-to-noise ratio, rapid acquisition, and flow-independent high signal from vessels, making it suited for cardiovascular imaging (9,10).…”

Diagnostic cross-sectional imaging of arterial diseases: really noninvasive?

“…Gjesdal et al [2] also used a balanced non-SSFP sequence which seems to be very promising. This sequence provides high blood-to-muscle contrast which, in combination with fat suppression, makes peripheral unenhanced MR angiography feasible (eg of the lower limbs).…”

“…For example, three recent major articles published during 2009-2010 show that it is possible to greatly reduce the risks of these techniques, by using unenhanced MRA on one hand [1,2], and by reducing both the amount of contrast medium and radiation dose required for CTA on the other [3].…”