Lionel Arrivé Hôpital Saint-Antoine Paris

Hanoi Nov 7th 2015

Introduction

�  Anatomy of lymphatic system is complex. �  Classical contrast lymphography is no more

performed, it was a rather invasive procedure specifically in patients with lymphoedema

�  Lymphoscintigraphy has a poor spatial resolution �  MR lymphography with very heavily T2-weighted

MR images provides an excellent analysis of both lymphatics vessels and lymph nodes without need of any contrast media

Non contrast MR lymphography

•  No need of any contrast injection •  Very heavily T2-weighted MR images •  High signal intensity of stationary fluid •  Low signal intensity of blood and tissue

Diagnosis of lymphoedema with MR lymphography

•  Positive diagnosis: collection around muscular area, subcutaneous infiltration with a honeycomb pattern and dermal thickening

•  Severity of lymphoedema and controlateral evaluation

•  Differential diagnosis: lipoedema •  Pattern of lymphoedema : aplasic, hypoplasic,

hperplasic/dysplasic

Secondary lymphoedema

•  Lower limbs or upper limbs •  Surgery (lymphadenectomy)

and/or radiation therapy •  Localisation of obstruction •  Evaluation of distal dilatation

Retroperitoneal lymphatic system Multiple anatomic variants

� Alternating bands of constriction (valves) and dilatation

� Marked variations from thin or prominent thick channels, parallel or converging vessels, vascular plexus

� The cisterna chyli is described as a saccular area of dilatation at the L1-L2 level at confluence of right and left lymphatic trunks

� Abdominal confluence of lymphatic trunks

Abdominal lymphatic vessels Multiple anatomic variants

•  HEPATIC LYMPHATIC VESSELS – Deep and superficial drainage: small – Retroportal vessels : commonly seen

•  PROXIMAL MESENTERIC VESSELS – Commonly observed – Join retroperitonal vessels

•  PANCREATIC LYMPHATICS VESSELS – Multiple and frequently demonstrated

The « so-called » cystic lymphangioma

•  Developmental abnormality characterized by lack of communications of regional vessels resulting in marked dilatation

•  Retroperitoneal lymphangioma are more common than mesenteric lymphangioma

•  Multilocular, elongated shaped, fluid-filled cystic lesion either bulky or infiltrative Ø Continuous spectrum of change from normal variants to cystic lymphangioma

Hepatic lymphatic pathology •  Hepatic lymphatic vessel dilatation is

observed in many liver diseases •  Dilatation of both superficial and deep

system are commonly observed in portal hypertension

•  Short localized dilatation is observed in severe chronic biliary obstruction

•  Lymphedema and lymphatic vessel dilatation are observed in many diseases and after liver transplantation

Lymphatic pathology of the spleen

•  Splenic cystic lymphangioma is common •  Imaging features are markedly variable

from multiple small and cystic to heterogeneous and large lesion

Ø It is of paramount importance to demonstrate associated lymphatic vessels abnormalities to strengthen the diagnosis

Lymphatic pathology of the kidney

•  Filariasis-related chyluria remains endemic in many countries

•  Chyluria is also observed in primary or secondary lymphangiectasia

Ø It is important to demonstrate the site

and level of communication between lymphatic vessels and urinary system

Post operative conditions •  Dilatation of the lymphatic vessels and of

the cisterna chyli is commonly observed after retro peritoneal, esophageal or pancreatic surgery (lymphadenectomy)

•  Post operative lymphoceles are common •  Lymphatic injury may result in large chylous

collection, chylous ascites and chylothorax Ø MR lymphography commonly

demonstrates the site, the level and the cause of the leak

Conclusion

•  Non invasive imaging procedure •  Spatial resolution still suboptimal •  Unique imaging modality for evaluation

of lymphatic system anatomy •  Common lymphatic abnormalities such

as cystic lymphangioma, lymphedema, lymphatic dilatation

•  Other uncommon diseases