Diagnosis of deep vein thrombosis using 3D black-blood thrombus imaging (BTI): preliminary clinical experience

Abstract

Background Deep vein thrombosis (DVT) is a common but elusive illness that can lead to fatal pulmonary embolism and sudden death. Effective treatment of DVT requires accurate evaluation of thrombus distribution and stage. MRI is one of diagnostic imaging modalities for DVT, and two conventional methods are MPRAGE[1] and CE-MRV[2]. Recently, 3D T1-weighted variable-flipangle turbo spin-echo (SPACE) was proposed as a black-blood technique that permits more direct visualization of DVT[3]. However, signal suppression of tremendously slow venous blood flow remains a challenge for SPACE. The unsuppressed blood signal could be a confounder in thrombus detection[3]. We hypothesized that the 3D black-blood thrombus imaging (BTI) technique[4] that combines SPACE with DANTE black-blood preparation[5] (DANTE-SPACE) might address the above issue. Methods Experiment The IRB-approved study was performed on a 3T scanner (Siemens TimTrio, Germany). DANTE-SPACE was first optimized on 8 healthy subjects (4 F 4 M, age 25 ± 4) and then tested on 12 patients (6 F 6 M, age 52 ± 13) with DVT. The optimized parameters for DANTE included: FA 15°, pulse trains 175, RF gap 1 ms, gradient 20 mT/m. The parameters for SPACE included: 3D coronal imaging with a resolution of 1.1 × 1.1 × (1.1-1.3) mm (interpolated to 0.55 × 0.55 × [0.55-0.65] mm),TR/ TE 650/9.8 ms, turbo factor 40, GRAPPA 2, scan time ~4 min. The scan was targeted to the thrombus region that was pre-determined by ultrasound within 3 days. Conventional SPACE, MPRAGE, and CE-MRV were conducted for comparison.