chapter  16
14 Pages

MR of the Lymphatics

WithAlberto Alonso-Burgos, Emilio García Tutor, Teresa Pérez de la Fuente, and Ángeles Franco López

Once blood constituents leave the microvascular exchange blood vessels, it becomes interstitial fluid. Lymph is the fluid that is formed when interstitial fluid enters the initial lymphatic vessels of the lymphatic

CONTENTS

16.1 Lymphatic Vascular System ...................................................................................................................................... 353 16.1.1 Mechanisms of Lymph Transport .............................................................................................................. 354

16.2 Lymphedema .............................................................................................................................................................. 355 16.2.1 Classification ................................................................................................................................................. 355

16.2.1.1 Primary Lymphedema ................................................................................................................ 355 16.2.1.2 Secondary Lymphedema ............................................................................................................ 356

16.2.2 Clinical Presentation .................................................................................................................................... 356 16.2.3 Treatment ....................................................................................................................................................... 357

16.2.3.1 Conservative Therapy ................................................................................................................. 357 16.2.3.2 Surgical Therapy .......................................................................................................................... 357

16.3 MR for the Lymphatics: How and When? .............................................................................................................. 358 16.3.1 Establishing a Reference System and How to Locate a Lymphatic ....................................................... 358

16.3.1.1 Lower Limbs Studies ................................................................................................................... 359 16.3.1.2 Upper Limbs Studies ................................................................................................................... 360 16.3.1.3 Locating a Lymphatic .................................................................................................................. 360

16.3.2 MRL Technique ............................................................................................................................................. 360 16.3.2.1 MRL Technical Parameters ........................................................................................................ 360 16.3.2.2 Contrast-Medium Application ................................................................................................... 361

16.3.3 Visual Image Analysis ................................................................................................................................. 363 16.4 Radiological Findings ................................................................................................................................................ 364 16.5 Limitations to MRL .................................................................................................................................................... 365 Bibliography ........................................................................................................................................................................... 365

system (Figure 16.1). This lymphatic vascular system serves key physiological functions:

• Maintains fluid homeostasis by absorbing water and macromolecules from the interstitium

• Enables uptake of dietary lipids and vitamins in the intestine and serves as a trafficking route for immune cells

The lymphatic system can be broadly divided into the conducting system and the lymphoid tissue.