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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