title: Magnetic resonance imaging of lymphatic vessels without image subtraction: a practicable imaging method for routine clinical practice?
abstract: OBJECTIVE
  To assess the feasibility of a time-efficient, high-resolution magnetic resonance lymphangiography (HR MRL) protocol without image subtraction for the detection of lymphatic vessels in patients with primary and secondary lymphedema.
  
  
  METHODS
  Three consecutive patients with lymphedema of the lower extremities (2 primary bilateral, 1 secondary unilateral) underwent HR MRL without image subtraction. An amount of 9 mL of gadodiamide and 1 mL of mepivacaine hydrochloride 1% were subdivided into 5 portions and injected intracutaneously into the dorsal aspect of each foot outside the scanner before image acquisition. Magnetic resonance imaging was performed with a 1.5-T system equipped with high-performance gradients. For HR MRL, a 3-dimensional, spoiled gradient-echo sequence (Volumetric Interpolated Breath-hold Examination) was used. The extent and distribution of the lymphedema was evaluated using a heavily T2-weighted, 3-dimensional turbo-spin echo sequence.
  
  
  RESULTS
  The HR MRL bilaterally detected the inguinal lymph nodes and the lymphatic vessels in the lower and upper leg in the 2 patients with primary lymphedema. In the patient with left-sided secondary lymphedema, the inguinal lymph nodes and the lymphatic vessels in the lower and upper leg were depicted on the right side. The diameter of the displayed lymphatic vessels varied between 1 and 5 mm. Three-dimensional, maximum-intensity projection images of different angles of view provided detailed outlining of the lymphatic vessels and differentiation from veins, which showed a lower signal intensity.
  
  
  CONCLUSIONS
  The HR MRL without image subtraction is safe, technically feasible, and has the potential to become a diagnostic imaging tool in daily clinical practice because of its time efficiency.
authors.affiliation: Division of Diagnostic Radiology, Department of Radiology, University Hospital of Freiburg, Freiburg, Germany. lohrmann@mrs1.ukl.uni-freiburg.de
authors.forename: Christian
authors.initials: C
authors.lastname: Lohrmann
authors.forename: Etelka
authors.initials: E
authors.lastname: Foeldi
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Bartholomä
authors.forename: Mathias
authors.initials: M
authors.lastname: Langer
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage; D003287:Contrast Media / Q000008:administration & dosage; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007866:Leg / Q000473:pathology; D042601:Lymphatic Vessels / Q000473:pathology*; D008209:Lymphedema / Q000175:diagnosis*; D008220:Lymphography / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D013382:Subtraction Technique
chemical_list: D000779:Anesthetics, Local; D003287:Contrast Media; C064925:gadodiamide; D008619:Mepivacaine; D019786:Gadolinium DTPA