J Korean Radiol Soc.  1995 Jul;33(1):87-92.

Peri portal Low-Attenuation: A CT Sign of Lymphatic Obstruction

• Lee SH
• Han YM
• Choi KC
• Kim CS
• Lee SY
• Chung GH
• Sohn MH
• Yang DH
• Lee YW

Abstract

PURPOSE
Periportal low attenuation, defined as a low attenuation rim around the portal vein and its branches which is seen on contrast material-enhanced CT scans, has been described in a variety of conditions. We tried to document that lymphatic obstruction is one of the major cause of periportal low attenuation.
METHODS
AND MATERIALS: We retrospectively analyzed 57 cases of periportal low attenuation on abdominal CT scans and also reviewed the surgical records in 32 cases. Lymph node enlargement in the hepatoduodenal ligament which is a main lymphatic channel from the liver were analyzed and calculated the ratio of the transeverse diameter between the inferior vena cava and the aorta at the level of right adrenal gland. After complete surgical interruption of the lymphatic drainage from the liver in a dog, follow up CT scans were obtained and correlated with pathologic findings.
RESULTS
Fifty patients(88%) had underlying disease which could cause impairment of lymphatic drainage. Periportal low attenuation was identified in several clinical conditions, including surgical lymph node dissection, lymphadenopathy in the hepatoduodenal ligament, blunt trauma. In animal model, CT scan showed prominent periportal low attenuation at 5 days after surgery. Histologic examination revealed numerous dilated lymphatic vessels and a marked lymphedema in the connective tissues surrounding the portal vein and its major branches.
CONCLUSION
One of the major.cuase of periportal low attenuation was impaired lymphatic drainage and periportal low attenuation corresponding to the numerous dilated lymphatic vessels and a marked lymphedema in the connective tissues surrounding the portal vein and its major branches.

MeSH Terms

Adrenal Glands
Animals
Aorta
Connective Tissue
Dogs
Drainage
Follow-Up Studies
Ligaments
Liver
Lymph Node Excision
Lymph Nodes
Lymphatic Diseases
Lymphatic Vessels
Lymphedema
Models, Animal
Portal Vein
Retrospective Studies
Tomography, X-Ray Computed
Vena Cava, Inferior