1351720 - Staging a Successful Dynamic Contrast-Enhanced Magnetic Resonance Lymphangiogram with Congenital Heart Disease

Background: Dynamic contrast-enhanced magnetic resonance (MR) lymphangiography (DCMRL) is an emerging technique for the detection of lymphatic channels following single ventricle palliation.  Proper equipment and facility set-up is essential for a successful DCMRL.

Methods: Staging of the initial part of the procedure should be done in zone 3 of the MR suite with enough space to hold staff (MR technicians and nurses), physicians, and equipment, including the anesthesia console, ultrasound machine for access, and MR table trolley (Figure 1).  The MR trolley allows the table to be undocked from the magnet in zone 4, and taken to zone 3, where the interventional team can drape the patient and maintain sterility.
 
Four fiducial markers are added to the patients torso to assist with 3-dimensional overlay interventional planning.  In zone 3,  after the environment has been made sterile, two 25g needles are inserted using ultrasound guidance into bilateral inguinal lymph nodes (Figure 2). After access is obtained, usage of the MR table trolley ensures no further transfers to minimize risk of dislodging the needles.  The interventionalist injects contrast into bilateral inguinal lymph nodes simultaneously to start the dynamic portion of the DCMRL.

DCMRL was performed using a 1.5-T magnet (Philips Ingenia) using diluted gadobutrol (Gadavist, Bayer Healthcare) at a dose of 0.1 ml/kg, administered by timed manual hand injection at a rate of 1-2 ml/sec. Scanning parameters were as follows: repetition time 4.2ms; echo time 1.2 ms; temporal resolution 35 ms; isotropic voxel size, 1.4 x 1.4 x 1.4 mm.

Prior to dynamic contrast, T2-weighted 3-dimensional turbo spin echo imaging was performed with maximal intensity projection reconstructions to provide additional information on lymphatic burden.  Time-resolved angiography was performed using 3-dimensional steady state free precession imaging without motion compensation and without keyhole imaging to provide instantaneous image reconstruction and real time imaging during contrast injection (Figure 3). Following completion of contrast injection, an additional T1-weighted 3-dimensional balanced steady state free precession imaging sequence was performed.

Results: Patients were referred for known lymphatic leakage (chylothorax, plastic bronchitis, chylopericardium, or protein losing enteropathy). Of the 27 cases that were performed, 54 inguinal lymph nodes were successfully accessed with only one infiltrate. Cases were transported for intervention following DCMRL.

Conclusion: With this framework, a successful DCMRL program for lymphatic intervention can be established to facilitate treatment for pediatric patients with lymphatic abnormalities.  This methodology allows for excellent success of intervention with minimal complications by utilizing space in MR zone 3 for equipment and staff, sterilization, and inguinal access, an MR compatible table trolley system to transport the patient in and out of zone 4 and an adjoining interventional suite for lymphatic intervention.