[Show abstract][Hide abstract] ABSTRACT: To characterize vascular lesions in SSc disease with high-resolution magnetic resonance angiography (Micro-MRA) of the finger.
Eight SSc subjects and eight age- and sex-matched healthy controls were recruited for this study. Among the SSc subjects, the mean +/- s.d. age was 54.5 +/- 4.9 yrs, and the mean +/- s.d. duration of disease was 8.3 +/- 8.4 yrs. The numbers of SSc subjects that had telangiectasia, calcinosis and impaired finger flexion were 3, 2 and 3, respectively. The 2D time-of-flight micro-MRA was performed on a 3T clinical MRI scanner using a custom-designed finger coil with an in-plane resolution of 0.16 x 0.21 mm(2) and slice thickness of 1.2 mm. The data for the proper palmar digital artery lumen area, the number of visible dorsal digital veins and a semi-quantitative vascular score, which evaluates the overall integrity of digital vessels, were independently evaluated by two experienced reviewers who were blinded to the status of the subject.
Micro-MRA detected significant differences in the digital vasculature between SSc subjects and healthy volunteers. The SSc subjects had a significantly decreased digital artery lumen area (0.13 +/- 0.06 vs 0.53 +/- 0.26 mm(2), P < 0.001), a reduced number of digital veins (0.63 +/- 1.06 vs 3.13 +/- 0.99, P = 0.001) and a lowered overall vascular score (1.75 +/- 1.04 vs 3.5 +/- 0.53, P = 0.001). The study also found that both the digital artery lumen area (Pearson's; r = -0.72, P = 0.044) and vascular scores (Spearman's; rho = -0.75, P = 0.047) of the SSc subjects were inversely correlated with the duration of the disease.
Micro-MRA can be used to identify and quantitatively characterize the vascular disease in SSc fingers. The parameters derived from micro-MRA could potentially be used as prospective biomarkers for clinical evaluation.
Full-text · Article · Aug 2008 · Rheumatology (Oxford, England)
[Show abstract][Hide abstract] ABSTRACT: Introduction Multi contrast black blood (BB) carotid imaging is important for atherosclerosis diagnosis and accurate plaque component characterization [1, 2]. However, the most popular blood suppression methods, such as inflow pre-saturation band and double inversion recovery (DIR) are still susceptible to plaque mimicking flow artifacts that come from stagnant or slow flow. An alternative technique originally named 'diffusion preparation' sequence in combination with SSFP sequence has recently been proposed as a BB technique for vessel wall imaging . This method, however, actually achieves BB effect by de-phasing rather than diffusion effect. Therefore, we would prefer to avoid the term 'diffusion', but naming it as motion sensitized driven equilibrium (MSDE) sequence. Unlike multi-contrast turbo spin echo (TSE) sequence, SSFP technique has a limited ability to discriminate plaque components. In this report, the MSDE preparation sequence is combined with the TSE sequence and compared to a previously validated multislice DIR sequence . Methods Sequence Fig. 1 shows the MSDE sequence that is used in this study. The sequence is fully balanced around the 180º pulse. In the presence of flow, the flow suppression efficiency is determined by the de-phasing among moving spins, which is further determined by first and higher order gradient moments. To avoid any phase incoherence of the static spin, the total zeroth gradient moment value is kept to be zero. Optimization The BB capability of MSDE pre-pulse was first validated on a flow phantom (Phantom by Design, Bothell, WA). It was then optimized for in vivo scan to achieve the best blood suppression efficiency and also avoid significant signal drop caused by diffusion and T2 decay. All scans were performed on a 3T scanner (Philips Achieva R1.5.4, Best, Netherlands). A healthy volunteer (32, Male) was scanned after obtaining the informed consent. Oblique carotid artery scans (TR/TE 2000/8ms, FOV 160*160ms, slice thickness 2mm) with various first gradient moment values were performed at the same location. CNR between sternocleido muscle and lumen is used as the optimization goal. The sequence that presents highest CNR was chosen in the following comparison study. In vivo comparison The MSDE sequence is compared with the previously validated multi-slice DIR sequence  with TI of 290ms. Both MSDE and mDIR sequences use exactly the same T2w TSE readout sequence. The readout parameters are: TR/TE 4000/53ms, FOV 160*160mm, matrix 256*256, slice thickness 2mm, NSA 1. To compare the blood suppression efficiency, transversal MR images around carotid bifurcation were acquired on 3 atherosclerotic patients (mean age 59, 2M1F) after obtaining informed consents. After the images are acquired, the following comparisons were conducted.