Thomas C. Lauenstein MD, Presenter: Nothing to Disclose

Lale Umutlu MD, Abstract Co-Author: Consultant, Bayer AG

Anja Fischer, Abstract Co-Author: Nothing to Disclose

Anton Quinsten, Abstract Co-Author: Nothing to Disclose

Christian Kloeters MD, Abstract Co-Author: Nothing to Disclose

Sonja Kinner MD, Abstract Co-Author: Nothing to Disclose

The throracic outlet syndrome (TOS) is defined as a positional compression of the subclavian and vertebral artery. TOS can be diagnosed by magnetic resonance angiography (MRA) performed in association with postural maneuvers. However, this technique requires high amounts of gadolinium and exact timing of contrast delays. A new time-resolved MRA technique (TWIST) combines parallel imaging with a 3D view sharing implementation. Thus, 3D datasets can be collected with high temporal resolution and only little intravenous gadolinium. We aimed to assess whether TOS can be diagnosed with TWIST MRA.

21 patients with suspected TOS were included. Examinations were performed on a 1.5-T system (MAGNETOM Avanto; Siemens). A Body Matrix RF surface coil was used for signal reception of the upper thorax. Following the i.v. administration of 3cc gadobutrol (Gadovist, Bayer) at a flow-rate of 3 cc/s, 20 consecutive coronal T1-weighted 3D datasets were acquired using a TWIST protocol (TR/TE/flip = 2.5ms/0.9ms/25°; matrix: 384x202; 60slices; temporal resolution: 3.0s). The acquisition was performed twice: with the arms alongside the body and after elevation. Images were analyzed with regards to stenotic changes of the subclavian arteries. Results of subsequent B-mode and color duplex ultrasonography were used as the standard of reference.

6 patients did not reveal a stenosis of the right or left subclavian artery. In 15 patients a compression of the subclavian artery was observed after arm elevation (unilateral n=9, bilateral n=6). Findings were confirmed by the standard of reference.

TWIST MRA is a fast and robust technique to identify patients with TOS.

MRA should be applied using the TWIST technique to diagnose TOS as only a small amount of gadolinium is applied. In addition, high temporal resolution overcomes the need for exact contrast timing.

Lauenstein, T, Umutlu, L, Fischer, A, Quinsten, A, Kloeters, C, Kinner, S, Time-resolved MR Angiography with Interleaved Stochastic Trajectories (TWIST) for the Diagnosis of Thoracic Outlet Syndrome.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11012022.html